Patent Application
20230207426
The present invention relates to the field of (1) microscale or millimeter scale active heat transfer devices or arrays (HTDs or HTAs) with single stage or multiple stage jetting structures that provide directed fluid flow to a primary heat transfer surface or impact surface for use in providing thermal management of semiconductors or other devices during fabrication, or testing, (2) cold plates incorporating such devices or arrays as well as inlet and outlet interfaces with single stage or multistage divisions that are in addition to any such stages that form part of an HTD or HTA wherein the cold plate provides for cooling or temperature moderation of a heat source, (3) systems incorporating such HTAs and/or cold plates that may additionally include pumps, heat exchangers, and/or filters as well as additional active or passive cooling or heating elements, and (4) electrochemical, multi-layer fabrication of micro-scale or mesoscale three-dimensional structures, parts, components, or devices where each layer is formed from a plurality of deposited materials and more specifically use of such methods in forming in whole or in part such microscale HTDs or HTAs.
Thermal Management
Current and next generation high performance electronic devices are reaching such high heat flux levels that new liquid cooling strategies are required. To tackle this problem, liquid cooled micro-heat exchangers have been in development for some time, though they have not seen wide commercial penetration. One reason for this is that these next generation micro-cooling systems with complex inner geometries require equally complex manufacturing technologies in order to fabricate them. This being the case, many micro-cooling concepts have been conceptualized using CFD modelling tools, though they cannot be implemented without appropriate manufacturing technology to realize them physically.
An example of a thermal management cold plate can be found in a paper entitled “Direct Liquid Jet-Impingement Cooling with Micron Sized Nozzle Array and Distributed Return Architecture” by Thomas Brunschwiler, Hugo Rothuizen, Matteo Fabbri, Urs Kloter, Bruno Michel, R. J. Bezame, and Govindarajan Natarajan from the Thermal and Thermalmechanical Phenomena in Electronics Systems 2006, ITERM '06 conference.
A second example of a thermal management system for semiconductor devices and other sources can be found in U.S. Pat. No. 9,953,899 (Microfabrica Docket No. P-US349-A-MF).
A third example of a thermal management system can be found in a conference paper entitled, “A New Hybrid Heat Sink with Impinging Micro-Jet Arrays and Microchannel Fabrication Using High Volume Additive Manufacturing by A. J. Robinson, W, Tan, R. Kempers, J. Colenbrander, N. Bushnell, and R. Chen from the January 2017 33rd Thermal Measurement, Modeling & Management Symposium (SEMITHERM).
A fourth example of thermal management systems and an analysis of them can be found in the University of Sheffield thesis entitled “Evaluation of Thermal Management Solutions for Power Semiconductors by Manoj Balakrishnan and labeled with a date of May 2016.
Each of these patent applications and other publications are incorporated herein by reference as if set forth here in full.
Electrochemical Fabrication:
Electrochemical fabrication techniques for forming three-dimensional structures from a plurality of adhered layers have been, and are being, commercially pursued by Microfabrica® Inc. (formerly MEMGen Corporation) of Van Nuys, Calif. under the process names EFAB and MICA FREEFORM®.
Various electrochemical fabrication techniques were described in U.S. Pat. No. 6,027,630, issued on Feb. 22, 2000 to Adam Cohen.
A related method for forming microstructures using electrochemical fabrication techniques is taught in U.S. Pat. No. 5,190,637 to Henry Guckel, entitled “Formation of Microstructures by Multiple Level Deep X-ray Lithography with Sacrificial Metal Layers”.
Electrochemical fabrication provides the ability to form prototypes and commercial quantities of miniature objects, parts, structures, devices, and the like at reasonable costs and in reasonable times. In fact, electrochemical fabrication, and in particularly multi-layer electrochemical fabrication, is an enabler for the formation of many structures that were hitherto impossible to produce. Electrochemical fabrication opens the spectrum for new designs and products in many industrial fields. Even though electrochemical fabrication offers this capability, and it is understood that electrochemical fabrication techniques can be combined with designs and structures known within various fields to produce new structures, certain uses for electrochemical fabrication provide designs, structures, capabilities and/or features not known or obvious in view of the state of the art.
A need exists in various fields for miniature devices having improved characteristics, improved operational capabilities, reduced fabrication times, reduced fabrication costs, simplified fabrication processes, greater versatility in device design, improved selection of materials, improved material properties, more cost effective and less risky production of such devices, and/or more independence between geometric configuration and the selected fabrication process.
Some embodiments of the invention are directed to heat transfer arrays (HTAs) that may be placed in contact with, or in proximity to, operating semiconductors, other operating heat sources, or heat sink materials in contact with such semiconductors or heat sources to provide enhanced cooling or heat dissipation. These heat transfer arrays may take the form of microjet arrays, hybrid microchannel microjet arrays, integrated fin and microjet arrays, and even hybrid microchannel and integrated fin and microjet arrays. In some embodiments, the HTAs may be accompanied by heating elements that can provide for two directional temperature control wherein the heating elements may be located between the HTA(s) and the heat source to be temperature modulated or in another position relative to the HTAs or the heat source. Such heating elements may provide general heating or area specific heating depending either on anticipated heat production by the source or measured temperature variations that are to be moderated. If necessary, such heating elements may be electrically isolated from any conductive material forming the HTA. In combination with appropriate inlet and outlet headers and or manifolds, these heat transfer arrays and optional heating elements might be called cold plates or active heat sinks. In combination with pumps, heat exchangers, appropriate functional connections (e.g. tubing, channels), optional filters, optional sensors (e.g. pressure, temperature, flow, and the like), and optional storage reservoirs, and the like, these cold plates (individually or in groups) may form thermal management control systems.
Some embodiments may provide heat transfer arrays that may be located side-by-side or in lateral proximity to each other to provide extended lateral cooling of a surface.
Some embodiments may provide heat transfer arrays that include N inlet splitting or passage dividing stages and R outlet passage recombination stages where N>R.
Some embodiments may provide heat transfer arrays and/or cold plates with inlets and outlets located vertically above the heat transfer array jetting elements.
Some embodiments may provide heat transfer arrays and/or cold plates having first inlet path-to-jet outlet orifice flow impedances, or average impedances, Zi, and second post jetting-to-outlet flow impedances, or average impedances, Zo, where the inlet flow impedance is greater than the outlet flow impedance, such as, for example, where Zi/(Zo+Zi) has a value greater than 0.55, 0.6, 0.7, 0.8, 0.9, or even 0.95.
Some embodiments provide heat transfer arrays or cold plates that are laterally scalable without inlet or outlet passage causing one or more lateral regions of a heat transfer array to have a significantly reduced heat transfer rate (RHTR) compared to the other heat transfer rates of the array or the overall average heat transfer rate (AHTR) of the array where the significantly less is defined as the ratio of RHTR/AHTR being less than 60%, 70%, 80%, or 90%.
Some embodiments provide heat transfer arrays or cold plates with one or more (1) wells with nearest neighbor flow path connections, (2) wells with second nearest neighbor flow path connections, (3) wells with a mixture of nearest and second nearest neighbor flow path connections, (4) well walls with non-flow channels that provide thermal expansion/contraction stress relief, (5) individual jets that direct flow into multiple wells, (6) jets with one configuration and wells with another, (7) Spacers on jets, on well walls, or on both, (8) spacers on a single jet or a well that provide lateral displacement inhibition in only one direction but not the opposite direction or in only one direction and not the perpendicular direction, (9) tabs on a jet that engage well walls to provide vertical positioning of the jets relative to the walls, (10) one or more tabs on a jet that provide balanced vertical force on the jet when encountering a well wall but where such balanced force is provided by tabs on a plurality of grouped jets, or (11) tabs that are attached to one of a jet wall or a corresponding well wall wherein the tabs provide a lateral restoring force to the relative position of the jet wall and the well wall when a displacement force is exerted on one relative to the other.
In some embodiments, heat transfer arrays and their formation take advantage of the unmatched heat transfer coefficients and surface temperature uniformity associated with impinging microjet arrays together with the high surface area per unit volume associated with microchannels as can be implemented using multi-layer, multi-material electrochemical deposition (i.e., electrodeposition or electroless deposition) methods. Heat transfer arrays and inlet and outlet header or manifold designs may be modeled using computational fluid dynamics (CFD), for example, ANSYS Fluent Version 16.2 in combination with the capabilities of Microfabrica's MICA FREEFORM® process. In some embodiments, an extreme target heat flux of 1000 W/cm2 was considered along with a maximum surface temperature of 65° C. and a maximum surface temperature variation of below 10° C. Hydraulically, pressure drop was considered along with an overall volumetric flow rate limitation of 0.5 L/min for a 4 mm×4 mm package. In some embodiments, the heat transfer array was simulated using single phase laminar flow solver in Fluent and simulation of inlet and outlet headers. The simulations were multi-physics in nature as they included the heat flow throughout the internal solid metallic structures as well as the thermal field within the fluid. The designs of some embodiments, as simulated achieved their design goals, with a surface average heat transfer coefficient of 360 kW/m2K, for a flow rate of 0.5 L/min, and pressure drop of 1 atm. With an imposed heat flux of 1000 W/cm2, this may translate into a maximum surface temperature less than 58° C. and a surface temperature variation as small as 6° C.
It is an object of some embodiments of the invention to provide improved micro-scale or millimeter scale thermal management devices including variations of liquid (e.g., water) cooled heat transfer arrays.
It is an object of some embodiments of the invention to provide for the fabrication of such heat transfer array devices using multi-layer, multi-material electrochemical fabrication methods.
It is an object of some embodiments of the invention to provide improved micro-scale or millimeter scale thermal management devices including heat transfer arrays that can better manage or tolerate stresses resulting from thermal contraction and expansion or to minimize the extent of differential expansion.
It is an object of some embodiments of the invention to provide improved micro-scale or millimeter scale thermal management devices including heat transfer arrays that provide more uniform heat transfer rates.
It is an object of some embodiments of the invention to provide improved micro-scale or millimeter scale thermal management devices including heat transfer arrays that are configured to provide more improved lateral tiling.
Other objects and advantages of various embodiments of the invention will be apparent to those of skill in the art upon review of the teachings herein. The various embodiments of the invention, set forth explicitly herein or otherwise ascertained from the teachings herein, may address one or more of the above objects alone or in combination, or alternatively may address some other object ascertained from the teachings herein. It is not necessarily intended that any specific objects be addressed by any single aspect or embodiment of the invention.
In a first aspect of the invention, a microjet heat transfer array, comprises: (a) a plurality of microjet structures for directing fluid from at least one group inlet onto at least one surface of a primary heat exchange region, wherein the primary heat exchange region is selected from the group consisting of: (1) a surface of a heat source or a plurality of separated surfaces of a heat source, (2) at least one surface in proximity to one or more heat source surfaces wherein a separation distance between the at least one surface onto which jetting occurs and a surface or a plurality of separate surfaces of a heat source is selected from the group consisting of (i) <=10 mm, (ii) <=5 mm, (iii) <=2 mm, (iv) <=1 mm, (v) <500 um, (vi) <=200 um, (vii) <=100 um, (viii) <=50 um, (ix) <=20 um, and x) <=10 um; (3) at least one surface of a solid material separated from a surface or a plurality of separate surfaces of a heat source by a gap that is occupied by at least one highly conductive transfer material that may be a different solid, a semi-liquid, or a liquid wherein a thickness of the gap is selected from the group consisting of (i) <=10 mm, (ii) <=5 mm, (iii) <=2 mm, (iv) <=1 mm, (v) <500 um, (vi) <=200 um, (vii) <=100 um, (viii) <=50 um, (ix) <=20 um, and x) <=10 um; and (4) at least one surface of a solid that is in intimate contact with a surface or a plurality of separate surfaces of a heat source; and (b) a plurality of post jetting flow paths to direct the fluid from the primary heat exchange region to at least one group outlet, wherein the at least one surface of the primary heat exchange region onto which jetting occurs is closer, in the jetting direction, to the surface or the plurality of separate surfaces of the heat source than are the plurality of post jetting flow paths.
In a second aspect of the invention, a hybrid microjet and microchannel heat transfer array, comprises: (a) a plurality of microjet structures for directing a heat transfer fluid from at least one group inlet onto at least one surface of a primary heat exchange region that is similar to that noted in the first aspect; and (b) a plurality of post jetting microchannel flow paths to direct the heat transfer fluid from the primary heat exchange region to at least one group outlet, wherein the at least one surface of the primary heat exchange region onto which jetting occurs is closer, in the jetting direction, to the surface or the plurality of separate surfaces of the heat source than are the microchannel flow paths.
Numerous variations of the first and second aspects of the invention exist and include, for example: (1) the array of the second aspect wherein the at least one surface on to which jetting occurs comprises a plurality of jetting well surfaces with each jetting well surface surrounded by walls that direct fluid away from the jetting well surface into the microchannel flow paths; (2) the array of the first variation wherein each of the plurality of jetting surfaces is configured to directly receive jetted fluid from a single jet orifice; (3) the array of the second aspect where each of the plurality of jetting surfaces is configured to directly receive jetted fluid from a group consisting of two or more jet orifices; (4) the array of any of first or second aspects or first to third variations wherein the jets have elongated cross-sectional configurations (i.e. in a plane perpendicular to a jetting direction) with a length to width aspect ratio selected from the group consisting of (i) <=10 to 1, (ii) <=5 to 1, (iii) <=3 to 1, or (iv) <=2 to 1; (5) the array of the fourth variation wherein the length of the elongated cross-sectional configurations have an orientation that extends parallel to a primary flow direction of the fluid as the fluid flows from an inlet to the plurality of microjets; (6) the array of the second aspect, or any of the first to fifth variations as they depend directly or indirectly from the second aspect wherein the microchannels direct fluid received from the jetting structures along paths that flow past outside walls of the microjet structures initially in a direction that is substantially anti-parallel to the direction of jetting and then in a direction that is substantially perpendicular to the direction of jetting; (7) the array of the first variation, or any of second to sixth variations as they depend from the first variation, wherein the inlet is spaced further from the surface on to which jetting occurs than does a flow path through the microchannels after the fluid leaves the jetting wells; (8) the array of any of the first or second aspects or first to seventh variations wherein the device is configured to interface with a heat source that comprises a semiconductor device; (9) the array of any of the first or second aspects or first to eighth variations wherein the device comprises a component selected from the group consisting of (A) an IC; (B) a microprocessor; (C) an SOC; (D) an RFIC, e.g. an RF transmitter or RF receiver; (E) an optical transmitter or receiver; (F) a power amplifier; (G) a GPU; (H) a CPU; (I) a DSP; (J) an ASIC; (K) an APU; (L) an LED; (M) a laser diode; (N) a power electronic device, e.g. a power inverter or a power converter; (0) a photonic device, (P) a propulsion system; (Q) a solar array, e.g. for a micro satellite; (R) a radiator, e.g. for a micro satellite; (S) an engine of a micro drone; (T) a spacecraft component such as an SSPA; (U) a traveling wave tube amplifier; (V) a package that holds one or more of the devices of (A)-(T), and (W) a stack or plurality of stacks of devices sandwiched between separated heat transfer arrays or interleaved with multiple heat transfer arrays; (10) the array of either of the first or second aspects any of variations (1)-(7) wherein the density of jets is varies spatially, at least in part, based on spatial heat generation of the semiconductor device, wherein the jetting structures are placed laterally closer together in the regions where average heat production is highest compared to areas where heat production is lowest; (11) the array of any variations (8), or (9) or (10) as they depend from variation (8), wherein the majority of the heat exchange from a solid to the fluid occurs via a surface of a first metal and wherein selected portions of the array are formed from a second metal of higher thermal conductive than the first metal such that heat conductivity as a whole is improved relative to the heat conductivity if the second metal were replaced with the first metal; (12) the array of either aspect (1) or (2) or variations (1) to (11) wherein regions on to which jetted fluid impinges are strengthened with a material different from that used to form the side walls of the jetting structures; (13) the array of either aspect (1) or (2) or variations (1) to (12) wherein the array comprises a plurality of adhered planar layers of at least one material where successive layers can be distinguished by stair-stepped configurations and wherein layers extend laterally in a cross-sectional dimension and a layer stacking axis is substantially parallel to a direction of fluid jetting; (14) the array of either aspect (1) or (2) or variations (1) to (13) wherein the heat to be removed requires a heat flux, from at least a portion of the primary heat transfer region, selected from the group consisting of (i) >=200 W/cm2, (ii) >=400 W/cm2 and (iii) >=800 W/cm2); (15) the array of either aspect (1) or (2) or variations (1) to (14) wherein the temperature of the surface or the plurality of separate surfaces of the heat source are to be held to a temperature selected from the group consisting of (i) <=100° C., (ii) <=80° C., and (iii) <=65° C.; (16) the array of either aspect (1) or (2) or variations (1) to (15) wherein a variation in temperature over the surface or the plurality of surfaces of the heat source is to be held at a temperature selected from the group consisting of (i) <=20° C., (ii) <=15° C., and (iii) <=10° C.; (17) the array of either aspect (1) or (2) or variations (1) to (16) wherein a flow of the heat transfer fluid through the array is selected from the group consisting of (i) <=2.0 L/min per 4 mm×4 mm area covered by the array, (ii) <=1 L/min per 4 mm×4 mm area covered by the array, and (iii) <=0.5 L/min per 4 mm×4 mm area covered by the array; (18) the array of either aspect (1) or (2) or variations (1) to (17) wherein the heat source has a surface area covered by the array selected from the group consisting of (i) <=900 sq mm, (ii) <=400 sq mm, (iii) <=100 sq mm, (iv) <=25 sq. mm, (v) <=20 sq. mm, and (vi) <=16 sq. mm; (19) the array of aspect 2, and the first-eighteenth variations as they depend directly or indirectly from aspect 2 wherein at least a portion of the plurality of microjetting structures provide flow paths with a cross-sectional dimension in the range of 15 to 300 um and more preferably in the range of 30-200 um; (20) the array the second aspect or any of the first to nineteenth variations as they depend directly or indirectly from aspect 2 wherein at least a portion of the post jetting microchannels have a cross-sectional dimension in the range of 15-300 um and more preferably in the range of 30-150 um; (21) the array of either the first or second aspects or any of the first to twentieth variations wherein distal ends of a plurality of jetting structures are spaced from the at least one surface of the primary heat exchange region by length in the range of 15-200 um and preferably in the range of 30-100 um; (22) the array of either the first or second aspect or any of the first to twenty-first variations wherein a first height of at least a plurality of post jetting microchannels is in the range of 40 to 600 um and more preferably in the range of 80-300 um, and wherein the first height is measured along a portion of the microchannels that directs fluid flow in a direction substantially anti-parallel to a direction of flow of fluid through the jetting structures; (23) the array of either the first or second aspect and any of the first to twenty-second variations wherein a height of at least a plurality of the jetting structures is in the range of 300 urn to 1 mm and more preferably in the range of 400-800 urn; (24) the array of either the first or second aspect or any of the first to twenty-third variations wherein a height of at least a plurality of the jets is in the range of 300 urn to 1 mm and more preferably in the range of 400-800 urn wherein a second height of at least a plurality of post jetting microchannels is in the range of 300-2000 urn and more preferably in the range of 600-1000 urn, wherein the second height is measured along a portion of the microchannels that directs fluid flow in a direction substantially perpendicular to the direction of flow of fluid through the jetting structures; (25) the array of either the first or second aspect or any of the first to twenty-fourth variations wherein a jetting well height extends from the at least one surface of the primary heat exchange region to a height that is above a height at which fluid exits the jetting structures; (26) the array of either the first or second aspect or any of the first to twenty-fifth variations wherein the array is configured to use a heat transfer fluid that is a liquid; (27) the array of the twenty-sixth variation wherein the liquid comprises water; (28) The array of either the twenty-sixth or twenty-seventh variation wherein the water does not undergo a phase change during a process of cooling a semiconductor; (29) the array of either the first or second aspect and any of the first to twenty-eighth variations wherein a solid material separating two adjacent jetting wells comprises a core material surrounded at least partially by a shell material wherein the core material has a higher thermal conductivity than does the shell material and also has a lower yield strength; or (30) the array of either the first or second aspect or any of the first to twenty-ninth variations wherein the plurality of jetting structures function as fins that contact the at least one surface of the at least one primary heat exchange region whereby a lowest portion of the plurality of jetting structures is in solid-to-solid contact with the at least one surface of the primary heat exchange region while at least one opening exists in the jetting structures above the at least one surface of the primary heat exchange region such that the jetted fluid is free from an enclosing jetting channel within the jetting structure to impinge on the at least one surface of the primary heat exchange region.
In a third aspect of the invention, a microjet heat transfer array, comprises: (a) a plurality of fins with each fin providing an embedded microjet for directing fluid from at least one group inlet onto at least one surface of a primary heat exchange region that is similar to that noted in the first aspect; (b) a plurality of post jetting microchannel flow paths to direct the fluid from the primary heat exchange region to at least one group outlet, wherein the plurality of fins provide a solid conductive heat flow path from the at least one surface onto which jetting occurs.
Numerous variations of the third aspect exist including, for example: (1) the array of the third aspect wherein the surface onto which jetting occurs is closer, in the jetting direction, to the heat source than are the plurality of post jetting microchannel flow paths; (2) the array of the third aspect wherein each fin provides a plurality of conductive solid contact paths directly to the surface of the primary heat exchange region onto which jetting occurs; or (3) the array of the third aspect wherein each fin has an elongated cross-sectional configuration. Other variations are similar to those noted for the first and second aspects of the invention so long as those variations do not contradict or otherwise nullify the features of the third aspect.
In a fourth aspect of the invention, a micro cold plate, comprises: (a) at least one fluid inlet (e.g. a header or manifold); (b) at least one fluid outlet (e.g. a header or manifold); (c) a microjet heat transfer array similar to that of the first aspect.
In a fifth aspect of the invention, a micro cold plate, comprises: (a) at least one fluid inlet (e.g. a header or manifold); (b) at least one fluid outlet (e.g. a header or manifold); (c) a hybrid microjet and microchannel heat transfer array similar to that of the second aspect.
Numerous variations of the fourth and fifth aspects of the invention exist. Some such variations are analogous to the variations of the first and second aspects as well as to variations of those variations, mutatis mutandis, for example where the variation would apply to a cold plate as opposed to a heat transfer array.
In a sixth aspect of the invention, a micro cold plate, comprises: (a) at least one group fluid inlet; (b) at least one group fluid outlet; (c) a microjet heat transfer array similar to that of the third aspect.
Numerous variations of the sixth aspect of the invention exist. Some such variations are analogous to those noted above for the third aspect of the invention, mutatis mutandis, for example where the variation would apply to a cold plate as opposed to a heat transfer array. Other variations are similar to those noted for the fourth and fifth aspects of the invention so long as those variations do not contradict or otherwise nullify the features of the sixth aspect.
In a seventh aspect of the invention, a thermal management system for a semiconductor device, comprises: (1) at least one micro cold plate similar to that of the fourth aspect; (2) at least one flow path to move heated fluid, directly or indirectly, from the fluid outlet header or manifold of the at least one micro cold plate to a heat exchanger; (3) at least one flow path to move cooled fluid, directly or indirectly, from the heat exchanger back into the inlet header or manifold of the at least one micro cold plate; and (4) at least one pump functionally configured to direct the fluid through the at least one cold plate to the heat exchanger and back to the at least one cold plate.
In an eighth aspect of the invention, a thermal management system for a semiconductor device, comprises: (1) at least one micro cold plate similar to that of the fifth aspect; (2) at least one flow path to move heated fluid, directly or indirectly, from the fluid outlet header or manifold of the at least one micro cold plate to a heat exchanger; (3) at least one flow path to move cooled fluid, directly or indirectly, from the heat exchanger back into the inlet header or manifold of the at least one micro cold plate; and (4) at least one pump functionally configured to direct the fluid through the at least one cold plate to the heat exchanger and back to the at least one cold plate.
Numerous variations of the seventh and eighth aspects of the invention exist. Some such variations are analogous to the variations of the first and second aspects as well as to variations of those variations, mutatis mutandis, for example where the variations would apply to a system as opposed to a heat transfer array. Additional variations, include, for example: (1) a filter being located along the flow path between the outlet and the pump; (2) a filter being located along the flow path between pump and the inlet; (3) a filter being located along the flow path between pump and the heat exchanger; (4) the pump being mounted to a header or manifold of the cold plate; (5) the pump being spaced from the cold plate; (6) at least one temperature sensor and a control system for turning on the pump when a detected temperature is greater than a high temperature set point; (7) at least one temperature sensor and a control system for turning off the pump when a detected temperature is less than a low temperature set point; (8) the system comprises a plurality of microjet arrays with at least two of the arrays spaced from one another to remove heat from separated portions of a single integrated circuit; (9) the system comprises a plurality of microjet arrays with at least two of the arrays spaced from one another to remove heat from two different integrated circuits; (10) at least one pressure sensor to monitor fluid pressure in the flow paths; and (11) the micro cold plate comprises a single structure that provides both the inlet header or manifold and the outlet header or manifold.
In a ninth aspect of the invention, a thermal management system for a semiconductor device, comprises: (1) at least one micro cold plate, comprising: (a) at least one fluid inlet header or manifold; (b) at least one fluid outlet header or manifold; (c) a microjet and microchannel heat transfer array similar to that of the third aspect; (2) at least one flow path to move heated fluid, directly or indirectly, from the fluid outlet header or manifold of the at least one micro cold plate to a heat exchanger; (3) at least one flow path to move cooled fluid, directly or indirectly, from the heat exchanger back into the inlet header or manifold of the at least one micro cold plate; and (4) at least one pump functionally configured to direct the fluid through the at least one cold plate to the heat exchanger and back to the at least one cold plate.
Numerous variations of the ninth aspect of the invention exist. Some such variations are analogous to those noted above for the third aspect of the invention, mutatis mutandis, for example where the variation would apply to a system as opposed to a heat transfer array. Other variations are similar to those noted for the seventh and eighth aspects of the invention so long as those variations do not contradict or otherwise nullify the features of the ninth aspect.
In a tenth aspect of the invention, a method for the batch formation of a plurality of heat transfer arrays, comprises: (a) forming a plurality of successively formed layers wherein each successive layer comprises at least two materials and is formed on and adhered to a previously formed layer, one of the at least two materials being a structural material and the other of the at least two materials being a sacrificial material, and wherein the forming of each of the plurality of successive layers comprises: (i) depositing a first of the at least two materials; (ii) depositing a second of the at least two materials; (iii) planarizing the first and second materials to set a boundary level for the layer; and (b) after the forming of the plurality of successive layers, separating at least a portion of the sacrificial material from multiple layers of the structural material to reveal the plurality of heat transfer arrays, wherein each of the plurality of heat transfer arrays is similar to a heat transfer array of the first aspect.
In an eleventh aspect of the invention, a method for the batch formation of a plurality of heat transfer arrays, comprises: (a) forming a plurality of successively formed layers wherein each successive layer comprises at least two materials and is formed on and adhered to a previously formed layer, one of the at least two materials is a structural material and the other of the at least two materials is a sacrificial material, and wherein the forming of each of the plurality of successive layers comprises: (i) depositing a first of the at least two materials; (ii) depositing a second of the at least two materials; (iii) planarizing the first and second materials to set a boundary level for the layer; and (b) after the forming of the plurality of successive layers, separating at least a portion of the sacrificial material from multiple layers of the structural material to reveal the plurality of heat transfer arrays, wherein each of the plurality of heat transfer arrays, is similar to that of the second aspect.
Numerous variations of the tenth and eleventh aspects of the invention exist. Some such variations are analogous to the variations of the first and second aspects as well as to variations of those variations, mutatis mutandis, for example where the variations would apply to a method for fabricating a heat transfer array as opposed to a heat transfer array itself.
In a twelfth aspect of the invention, a method for the batch formation of a plurality of heat transfer arrays, comprises: (a) forming plurality of successively formed layers wherein each successive layer comprises at least two materials and is formed on and adhered to a previously formed layer, one of the at least two materials is a structural material and the other of the at least two materials is a sacrificial material, and wherein the forming of each of the plurality of successive layers comprises: (i) depositing a first of the at least two materials; (ii) depositing a second of the at least two materials; (iii) planarizing the first and second materials to set a boundary level for the layer; and (b) after the forming of the plurality of successive layers, separating at least a portion of the sacrificial material from multiple layers of the structural material to reveal the plurality of heat transfer arrays, wherein each of the plurality of heat transfer arrays is similar to that of the third aspect.
Numerous variations of the twelfth aspect of the invention exist. Some such variations are analogous to those noted above for the third aspect of the invention, mutatis mutandis, for example where the variation would apply to a method of fabrication as opposed to a heat transfer array. Other variations are similar to those noted for the tenth and eleventh aspects of the invention so long as those variations do not contradict or otherwise nullify the features of the twelfth aspect. Still further variations include, for example: (1) the array being configured to use a heat transfer fluid that is a liquid; (2) where the liquid of the first further variation comprises water; or (3) wherein the liquid of the first or second further variation does not undergo a phase change during a process of cooling a semiconductor.
In a thirteenth aspect of the invention, a method for the batch formation of a plurality of heat transfer arrays, comprises: (a) forming a plurality of successively formed layers wherein each successive layer comprises at least two materials and is formed on and adhered to a previously formed layer, one of the at least two materials is a structural material and the other of the at least two materials is a sacrificial material, and wherein the forming of each of the plurality of successive layers comprises: (i) depositing a first of the at least two materials; (ii) depositing a second of the at least two materials; (iii) planarizing the first and second materials to set a boundary level for the layer; and (b) after the forming of the plurality of successive layers, separating at least a portion of the sacrificial material from multiple layers of the structural material to reveal the plurality of heat transfer arrays, wherein the each of the plurality of heat transfer arrays, comprises features selected from the group consisting of: (1) a microjet array, (2) a plurality of microjet structures and microchannels that receive fluid after being jetted from jetting structures, and (3) a plurality of fins and microjet structures wherein the fins comprise at least a portion of the jetting structures including jetting channels and jetting orifices.
Numerous variations of the thirteenth aspect of the invention exist. Some such variations are analogous to those noted above for the first to ninth aspects of the invention, mutatis mutandis, for example where the variation would apply to a method of fabrication as opposed to a heat transfer array. Other variations are similar to those noted for the tenth to twelfth aspects of the invention so long as those variations do not contradict or otherwise nullify the features of the thirteenth aspect. Still further variations include, for example: (1) the method further comprising: (c) designing a 3D representation of the heat transfer array in 3D CAD, (d) dividing the representation into a plurality of stacked layer representations of successive cross-sections of the heat transfer array, and (e) providing further processing of the cross-sectional data to derive fabrication data for the heat transfer array, wherein the fabrication data is used in creating the successively formed layers; (2) wherein the array is configured to use a heat transfer fluid that is a liquid; (3) the liquid of the second further variation comprises water; (4) the array is configured such that the liquid of the second or third further variations does not undergo a phase change during a process of cooling a semiconductor; (5) the heat transfer array is formed primarily of one or more metals; and (6) a metal of the fifth further variation is deposited by electrodeposition.
In a fourteenth aspect of the invention, a method for the formation of a micro cold plate for semiconductor cooling, comprises: (a) forming a heat transfer array comprising: (1) forming a plurality of successively formed layers, wherein each successive layer comprises at least two materials and is formed on and adhered to a previously formed layer, one of the at least two materials is a structural material and the other of the at least two materials is a sacrificial material, and wherein each successive layer defines a successive cross-section of the three-dimensional structure, and wherein the forming of each of the plurality of successive layers comprises: (i) depositing a first of the at least two materials; (ii) depositing a second of the at least two materials; (iii) planarizing the first and second materials to set a boundary level for the layer; and (2) after the forming of the plurality of successive layers, separating at least a portion of the sacrificial material from multiple layers of the structural material to reveal the three-dimensional parts; (b) supplying a fluid inlet in the form of a header or manifold and a fluid outlet in the form of a header or manifold; and (c) attaching the microjet array to the fluid inlet and fluid outlet, wherein each of the heat transfer array, comprises features selected from the group consisting of: (1) a microjet array, (2) a plurality of microjet structures and microchannels that receive fluid after being jetted from jetting structures, and (3) a plurality of fins and microjet structures wherein the fins comprise at least a portion of the jetting structures including jetting channels and jetting orifices.
Numerous variations of the fourteenth aspect of the invention exist. Some such variations are analogous to those noted above for the first to ninth aspects of the invention, mutatis mutandis, for example where the variation would apply to a method of fabrication as opposed to a heat transfer array. Other variations are similar to those noted for the tenth to thirteen aspects of the invention so long as those variations do not contradict or otherwise nullify the features of the fourteenth aspect.
In a fifteenth aspect of the invention, a method for forming a thermal management control system for semiconductor cooling, comprises: (a) forming at least one heat transfer array using a process similar to that set forth in the fourteenth aspect; (b) supplying at least one fluid inlet in the form of a header or manifold and at least one fluid outlet in the form of a header or manifold; (c) providing at least one semiconductor device, at least one heat exchanger, and at least one pump; (d) attaching the at least one microjet array to the at least one fluid inlet and at least one fluid outlet; (e) functionally coupling the semiconductor device and the microjet array; (f) providing and functionally connecting at least one flow path to move heated fluid, directly or indirectly, from the fluid outlet header or manifold to a heat exchanger; (g) providing and functionally connecting at least one flow path to move cooled fluid, directly or indirectly, from the heat exchanger back into the inlet header or manifold; and (h) providing and functionally connecting at least one pump to direct the fluid through the at least one cold plate to the heat exchanger and back to the at least one cold plate, wherein each of the heat transfer array, comprises features selected from the group consisting of: (A) a microjet array, (B) a plurality of microjet structures and microchannels that receive fluid after being jetted from jetting structures, and (C) a plurality of fins and microjet structures wherein the fins comprise at least a portion of the jetting structures including jetting channels and jetting orifices.
Numerous variations of the fifteenth aspect of the invention exist. Some such variations are analogous to those noted above for the first to ninth aspects of the invention, mutatis mutandis, for example where the variation would apply to a method of fabrication as opposed to a heat transfer array. Other variations are similar to those noted for the tenth to fourteenth aspects of the invention so long as those variations do not contradict or otherwise nullify the features of the fifteenth aspect.
In a sixteenth aspect of the invention, a method of cooling a semiconductor device, comprises: (a) providing at least one heat transfer array, comprising a plurality of stacked and adhered layers comprising at least one metal wherein each of the at least one heat transfer array comprises features selected from the group consisting of: (1) a microjet array, (2) a plurality of microjet structures and microchannels that receive fluid after being jetted from jetting structures, and (3) a plurality of fins and microjet structures wherein the fins comprise at least a portion of the jetting structures including jetting channels and jetting orifices. (b) placing the heat transfer array in physical contact with or in proximity to the semiconductor device to be cooled to form a primary heat transfer region having at least one cooling fluid impingement surface; (c) pumping a cooling fluid into at least one inlet of the heat transfer array such that the cooling fluid is jetted onto the impingement surface to extract heat therefrom, then passing the heated cooling fluid to at least one outlet of the heat transfer array, while continuing to extract heat from the heat transfer array, and then on to a heat exchanger where heat is removed from the cooling fluid to produce cooled cooling fluid; and (d) circulating the cooled cooling fluid from the heat exchanger back into the at least one inlet array of the heat transfer array to repeat a flow cycle to draw heat from the at least one semiconductor device.
Numerous variations of the sixteenth aspect of the invention exist. Some such variations provide added features similar to those found in the previous aspects of the invention or in their variations. In some such variations the array is configured to use a heat transfer fluid that is a liquid, in others the liquid may be water, and in still others the cooling process may be provided to remove heat from a semiconductor device.
In a seventeenth aspect of the invention, a heat transfer array includes: (a) a plurality of microjet structures for directing fluid from at least one group inlet onto at least one surface of a primary heat exchange region, wherein the primary heat exchange region is selected from the group consisting of: (I) at least one surface of a heat source; (II) at least one surface in proximity to a heat source surface wherein a separation distance between the at least one surface onto which jetting occurs and at least one surface of a heat source is less than 10 millimeters; (III) at least one surface of a solid material separated from a surface of a heat source by a gap that is occupied by at least one highly conductive transfer material that is selected from the group consisting of: (A) a solid, (B) a semi-liquid, (C) a liquid, and (D) a gaseous material having a heat conductivity that is greater than that of aluminum; (b) a plurality of post jetting flow paths to direct the fluid from the primary heat exchange region to at least one group outlet comprising paths selected from the group consisting of: (I) flow paths that extend antiparallel to the jetting direction along a length that is greater than a width of the flow path that extends radially away from the jet, (II) flow paths that extend antiparallel to the jetting direction along a length that is greater than a height of a last stage of a multi-stage jet, (III) flow paths that extend through well walls that connect an interior of a jetting well to an interior of another jetting well, (IV) flow paths that extend through well walls that connect an interior of a jetting well to an interior of another jetting well wherein a width of a flow path connecting two such wells is less than a nominal diameter of one of the two such wells, and (V) flow paths that maintain the majority of the fluid from a given jet within a lateral extent from that jet that is no more than N lateral separation distances of neighboring jets before such fluid reaches a vertical separation from the jetting surface that is greater a height of the jetting channel of that jet, where N is selected from the group consisting of 1, 2, 3, 4, and 5.
Numerous variations of the seventeenth aspect of the invention existing and including for example: (a) a jetting configuration in combination with pre-jetting and post jetting fluid flow paths that provide the array with a uniform vertical heat conductivity across lateral dimensions of the heat transfer array with a possible exception of an external lateral wall region surrounding the array where uniformity has a maximum heat conductivity difference selected from the group consisting of: (I) less than 25%, (II) less than 20%, (III) less than 15%, (IV) less than 10%, and (V) less than 5%; (b) a configuration allowing two-dimensional side-by-side tiling of heat transfer arrays while maintaining a uniform vertical heat conductivity across the group of tiled arrays where uniformity has a maximum heat conductivity difference selected from the group consisting of: (I) less than 25%, (II) less than 20%, (III) less than 15%, (IV) less than 10%, and (V) less than 5%; (c) a number of inlet to jetting flow path splitting (or dividing levels) equal to N and a number of post jetting recombination stages equal to M, where N>M, and wherein a jet height is consider to be a height of associated with a final stage of the jet; (d) the at least one inlet comprises a plurality of inlets with at least a portion of the inlets being located above the jetting area of the plurality of microjet structures, wherein the at least portion of the inlets comprise an amount selected from the group consisting of: (I) a majority of the inlets, (II) more than 67% of the inlets, and (III) all the inlets; (e) the at least one inlet comprises a single inlet with the single inlet being located above the jetting area of the plurality of microjet structures; (f) the at least one outlet comprises a plurality of outlets with at least a portion of the outlets being located above the jetting area of the plurality of microjet structures, wherein the at least portion of the outlets comprise an amount selected from the group consisting of: (I) a majority of the inlets, (II) more than 67% of the inlets, and (III) all the inlets; (g) the at least one outlet comprises a single outlet with the single outlet being located above the jetting area of the plurality of microjet structures; (h) the HTA forming part of a cold plate that further comprises a manifold connected to the at least one inlet, with the manifold being located entirely above a region that is limited to all jetting structures, post jetting flow paths and intervening regions; (i) the HTA forming part of a cold plate that further comprises a manifold connected to the at least one outlet, with the manifold being located entirely above a region that is limited to all jetting structures, post jetting flow paths and intervening regions; (j) the heat transfer array having an inlet to jetting orifice flow impedance of I and a post jetting to exit impedance of J where I>J by an amount selected from the group consisting of: (1) at least 20%, (II) at least 50%, (II) at least 100%, (III) at least 200%, and (IV) at least 400%; (k) the heat transfer array having an average inlet to jetting orifice flow impedance (per jet) of I and an average post jetting to exit (per jet) impedance of J where I>J by an amount selected from the group consisting of: (I) at least 20%, (II) at least 50%, (III) at least 100%, (IV) at least 200%, and (V) at least 400%; (I) the heat transfer array is configured to be laterally scalable while providing uniform heat transfer rates from one side of the array to an opposite side of the array, where such rates per unit area within an average for the entire per unit area selected from the group consisting of: (I) within 5%, (II) within 10%, (III) within 20%, and (IV) within 30% wherein the unit area consists of no fewer than an area associated with 5% of plurality of jets; (m) the heat transfer array is configured such that the existence of a flow inlet region of the array does not cause any first portion of the heat transfer array to have a first heat transfer rate (HTR1) that is substantially different from a second heat transfer rate (HTR2) of a second similarly sized portion of the heat transfer array wherein substantially different is a difference in heat transfer rate that greater than D, where D is selected from the group consisting of: (I) 40%, (II) 30%, (III) 20%, (IV) 10%, and (V) 5%, and wherein the first and second portions include primary heat transfer regions that undergo jetting from a number of jets that is no less than an amount J where J is selected from the group consisting of (I) 20%, (II) 10%, and (III) 5% of the jets of the array; (n) the heat transfer array is configured such that the existence of a flow outlet region of the array does not cause any first portion of the heat transfer array to have a first heat transfer rate (HTR1) that is substantially different from a second heat transfer rate (HTR2) of a second similarly sized portion of the heat transfer array wherein substantially different is a difference in heat transfer rate that greater than D, where D is selected from the group consisting of: (I) 40%, (II) 30%, (III) 20%, (IV) 10%, and (V) 5%, and wherein the first and second portions include primary heat transfer regions that undergo jetting from a number of jets that is no less than an amount J where J is selected from the group consisting of no less than four jets and also no less (I) 20%, (II) 10%, and (III) 5% of the jets of the array; (o) the heat transfer array has wells into which jets provide fluid flow, wherein at least one condition exists that is selected from the group consisting of: (I) at least a portion of the wells have at least one nearest neighbor flow path connection; (II) at least a portion of the wells have at least one second nearest neighbor flow path connection; (III) at least a portion of the wells have a mixture of nearest and second nearest neighbor flow path connections; (IV) at least a portion of the well walls have non-flow channels that provide thermal expansion/contraction stress relief; (V) at least each of a portion of the jets direct a flow of fluid into a plurality of wells; (VI) at least a portion of the jets have configurations that are different from a configuration of their respective wells; (VII) at least a portion of the jets have configurations that are different from a configuration of other jets; (VIII) at least a portion of the wells have configurations that are different from a configuration of other wells; (IX) at least a portion of some jets each comprise at least one spacer on a side wall of the jets that sets a minimum spacing of other portions of such jets from their respective well walls; (X) at least a portion of some wells comprise walls that hold an inward extending spacer that sets a minimum spacing of the well walls from their respective jets; (XI) at least one spacer attached to a single jet that provides lateral displacement inhibition in only one direction but not in a direction selected form the group consisting or: (A) the opposite direction, and (B) a perpendicular direction; (XII) at least one spacer attached to a single well that provides lateral displacement inhibition of a respective jet in only one direction but not in a direction selected form the group consisting or: (A) the opposite direction, and (B) a perpendicular direction; (XIII) at least one tab connected to a jet that interacts with a well wall to provide a desired vertical spacing between a bottom of the jet and a jetting surface; (XIV) at least one tab connected to a jet that does not provide a balanced vertical force on the jet when encountering a well wall but where such a balanced forced is provided by tabs on a plurality of grouped jets; (XV) at least two deflectable tabs attached to at least one jet that provide a lateral restoring force when the at least one jet is misaligned with a defined location within at least one well; (XV1) at least two deflectable tabs attached to at least two partially opposing walls of at least one well which provide at least one respective jet with a lateral restoring force when the at least one respective jet is misaligned with a defined location with the at least one well; and (p) the separation distance is selected from the group consisting of an amount less than (I) 5 mm, (II) 2 mm, (III) 1 mm, (IV) 500 um, (V) <=200 um, (VI) <=100 um, (VII) <=50 um, (VIII) <=20 um, and (IX) <=10 um.
In an eighteenth aspect of the invention a micro cold plate, includes: (a) at least one fluid inlet selected from the group consisting of: (1) at least one header, and (2) at least one manifold; (b) at least one fluid outlet selected from the group consisting of: (1) at least one header, and (2) at least one manifold; (c) a heat transfer array according to the seventeenth aspect of the invention.
In a nineteenth aspect of the invention a micro cold plate, include: (a) at least one fluid inlet selected from the group consisting of: (1) at least one header, and (2) at least one manifold; (b) at least one fluid outlet selected from the group consisting of: (1) at least one header, and (2) at least one manifold; (c) a heat transfer array according to the seventeenth aspect of the invention and at least one of the variations of the seventh aspect of the invention noted above.
In a twenty-first aspect of the invention, a thermal management systems includes: (a) a micro cold plate according to the eighteenth aspect of the invention, (b) at least one flow path to move heated fluid, from the fluid outlet to at least one heat exchanger; (c) at least one flow path to move cooled fluid, directly or indirectly, from the at least one heat exchanger back into the fluid; and (d) at least one pump functionally configured to direct the fluid through the a loop including to, through, and out of the at least one cold plate and to, through, and out of the heat exchanger.
In a twenty-second aspect of the invention a thermal management system includes: (a) a micro cold plate according to the nineteenth aspect of the invention, (b) at least one flow path to move heated fluid, from the fluid outlet to at least one heat exchanger; (c) at least one flow path to move cooled fluid, directly or indirectly, from the at least one heat exchanger back into the fluid; and (d) at least one pump functionally configured to direct the fluid through the a loop including to, through, and out of the at least one cold plate and to, through, and out of the heat exchanger.
In other aspects of the invention, the heat transfer arrays may not be microscale or millimeter scale devices but instead macroscale devices that provide cooling of large scale structures and devices such as internal combustion engine blocks, jet engines, rocket engines, various high heat transfer components of engines, combustion chambers, power converters, electrical resistors, batteries, light sources, lasers, and the like. Such macroscale heat transfer arrays may be fabricated by various methods including traditional machining and assembly methods or additive fabrication methods such as stereolithography and casting, selective laser sintering, and other direct and indirect metal deposition methods. In some such embodiments, heat transfer array features, fluid channels, jet diameters, well sizes, fluid flow rates, and the like may be scaled with the device size or may retain micro-scale or millimeter scale dimensions as appropriate. In some such embodiments, the dimensions set forth herein for some devices' features may vary from those set forth while ratios of at least some dimensions may or may not scale.
Other aspects of the invention will be understood by those of skill in the art upon review of the teachings herein. These other aspects of the invention may provide various combinations of the aspects presented above as well as provide other configurations, structures, functional relationships, processes, and uses that have not been specifically set forth above.
FIG. 6D1 illustrates a side cross-sectional view of a portion of an HTA showing two jets, a cooling fluid impact surface or jetting surface, and a portion of a fluid return path that moves fluid past the jets wherein the cold plate includes jets formed from a first material, well walls formed from a second material, and an impact surface formed from a third material wherein the materials may be different.
FIGS. 6D2-6D5 show top views of four different versions of the structure of FIG. 6D1 showing different example configurations of fluid flow paths that might provide isolation of initial fluid return paths or connections between initial fluid return paths from different jets relative to one another (i.e., post jetting flow paths), wherein the fluid flow paths remain isolated until the tops of the well walls are exceeded (FIG. 6D2), wherein pairs of return paths have a passage that joins pairs of return paths to one another to provide further surface area for fluid to extract heat from the solid walls of the wells or fin structures (FIG. 6D3), wherein pairs of individual jets occupy combined well structures (FIG. 6D4), or wherein the individual return paths are joined to one another via crossed pairs of flow paths (FIG. 6D5).
FIG. 6E1 illustrates a side cross-sectional view of an HTA similar to that of FIG. 6D1 with the exception that the side-by-side pair of jets are not separated by a wall but have an opening between them that can act as a common fluid return path.
FIG. 6E2 to FIG. 6E7 illustrate six example top views of the heat transfer array portion of FIG. 6E1 with each example providing a two-by-two array of jets and with each having a different pattern of jetting well configurations and/or well connections that form part of post jetting group of fluid return paths with all sharing a common cross-sectional view as shown in FIG. 6E1, wherein FIG. 6E2 shows top and bottom side-by-side jet pairs having individual jetting wells that are connected by a single relatively narrow fluid flow path that is similar to that of FIG. 6D3 but rotated by 90° about an axis perpendicular to a plane of the top view; FIG. 6E3 shows each of the upper and lower pairs of side-by-side jets sharing a common well similar to that of FIG. 6D4 but rotated by 90° about an axis perpendicular to a plane of the top view; FIG. 6E4 shows that each jet of the two-by-two array has its own jetting well but with a relatively narrow fluid flow path (e.g. having a width less than ¼ of the corresponding width of the well and perhaps even less than ⅛ of the well width) connecting the closest edges of the wells to their nearest neighbors such that four connection paths join the four wells together; FIG. 6E5 shows that the four wells have similar connective paths as those shown in FIG. 6E4 but with the paths having moderate widths (e.g. between ¼ and ½ of the width of the individual wells) as opposed to relatively small widths; FIG. 6E6 illustrates a configuration where all four jets share a single well without any intermediate well wall or fin elements; and where FIG. 6E7 shows a configuration where all four jets have their own wells but with relatively narrow flow paths not only connecting nearest neighbors but also second nearest neighbors (i.e. the diagonal neighbors).
FIG. 7A1 provides a vertical cross-section of part of a jetting array having a plurality of jets, a plurality of wells, and a jetting surface wherein these three primary features may be formed from different materials and wherein some well walls include hollow regions that may or may not allow fluid flow but can provide some level of stress relief during changes in temperature or when operational temperatures are significantly different from fabrication temperatures, particularly when the well structure(s) or well wall fins are formed from a different material than that of the jetting surface.
FIG. 7A2 provides a top view of the array of FIG. 7A1 where it can be seen that the array provides a 2×2 configuration of jets and wells, the wells do not include fluid flow paths that connect them, and the hollow regions shown in FIG. 7A1 do not extend to the top of the wells.
FIG. 7A3 and FIG. 7A4 provide two cut views of alternative array hollow structure configurations that meet the constraints shown in FIG. 7A1 and FIG. 7A2 wherein the hollow regions of FIG. 7A3 are provided in the form of a number of discontinuous segments that form a grid pattern bisecting the well walls or fin structures around the well depressions while FIG. 7A4 provide a similar pattern of hollow regions where the paths are continuous in nature as opposed to being discontinuous.
FIGS. 7B1-7B4 provide longitudinal and lateral cross-sectional views of part of a jetting array having hollow regions within portions of the fin or well walls as did FIGS. 7A1-7A4 but with those hollow regions having a different configuration relative to those of FIGS. 7A1-7A4, wherein FIG. 7B1 provides a vertical or longitudinal cross-section (in a X-Z plane) showing that in the plane of the cross-section, hollow regions exist within the outer well walls but not in the central well wall, while FIGS. 7B2 and 7B3 provide cut views of the array of FIG. 7B1 along cut lines 7B2-7B2 and 7B3-7B3, and FIG. 7B4 provides a cross-section view along cut line of 7B4-7B4 of FIG. 7B3.
FIGS. 8A1 and 8A2, respectively, provide a vertical cross-section view in an X-Z plane and a cut view in an X-Y plane looking upward along the Z axis wherein jet walls, jet flow paths, jetting surface(s), and solid elements that vertically join the bottom of the jet walls to the jetting surface exist, wherein the solid elements convert the jetting functionality to a combined jetting and fin functionality (i.e., the combined jet and solid elements, or finjets, take on a dual jetting and a solid heat conductive fin functionality).
FIG. 8B1 and FIG. 8B2 provide examples of the heat array configuration of FIGS. 8A1 and 8A2 in two different states of formation according to another embodiment of the invention wherein FIG. 8B1 shows the jetting surface and the well walls formed separately from the jets and the connective elements while FIG. 8B2 shows the state of the process after the two portions are vertically shifted to form the complete array of FIGS. 8A1 and 8A2.
FIG. 8C1 and FIG. 8C2 are similar to those of FIGS. 8A1 and 8A2 with the exception that the connective elements that join the jets and the jetting surface are wider than the jet walls themselves and provide contact to the well walls in addition to the jetting surface wherein in FIG. 8C2, it can be seen that the connective elements do not provide a ring-like structure as do the jet walls but instead define discrete contact regions around which jetted fluid can flow. In other embodiments, other configurations are possible including the jets, the well walls, and the connective elements all being formed from the same material.
FIG. 8D1 and FIG. 8D2 are similar to those of FIGS. 8A1 and 8A2 with two exceptions: (1) the narrower connective elements are individually centered relative to the jet walls that they contact and (2) instead of just two elements bridging the jetting gap between each jet and the jetting surface, four connective elements are used.
FIGS. 8E1 and 8E2 respectively provide a configuration to be assembled as a vertical cross-sectional view and a downward looking cut view (FIG. 8E1) and as a vertical cross-sectional fully assembled view (FIG. 8E2) wherein the connective elements are provided with a pattern that allows placement of the jets using reasonable assembly processes that will always result in appropriate vertical support for the jets along with adequate jetting, connecting, and post jetting flow paths even without perfect lateral alignment of the jets and the well by positioning and sizing the standoffs relative to one another to always allow support and fluid flow.
FIGS. 8F1 and 8F2 provide views of another jetting array configuration but with a different type of bridging structure or connective elements that join the jets to the well walls as opposed to joining or contacting the jets to the jetting surface wherein FIG. 8F1 provides a vertical cross-sectional view and FIG. 8F2 provides an upward looking horizontal, or lateral, cut view along the cut line in FIG. 8F1 wherein the connective elements provide for a desired lateral alignment of the jets and the well walls and may also provide for retained vertical alignment along with the jets and the well walls and may also provide improved stress tolerances during temperature variations particularly when the jetting surface and the well walls or jets are made of different materials with different coefficients of thermal expansion, and wherein a single bridging element is provided for each jet.
FIGS. 8G1 and 8G2 provide views of another jetting array configuration with bridging structures or connective elements similar to those of FIGS. 8F1 and 8F2 that join the jets to the well walls but where one jet of the pair has two such bridging structures oriented along one lateral axis while the other has two bridging or connective elements oriented along a perpendicular lateral axis as can be seen in FIG. 8G2 which is taken along the cut line shown in FIG. 8G1.
FIGS. 8H1 and 8H2 provide views of a jetting structure in a preassembly state and a post assembly state, respectively, wherein a jetting surface and well walls are shown laterally aligned but vertically separated from the jets and bridging elements as shown in FIG. 8H1 while the jetting surface, well walls, jets and bridging elements are shown after assembly from both a cross-section vertical perspective (lower portion of FIG. 8H2) and a top view (upper portion of FIG. 8H2).
FIGS. 8I1-8I3 provide three views of another embodiment of a small heat transfer array where jets and wells are provided with elements for constraining excess movement while still allowing some movement wherein FIGS. 8I1 and 8I2, respectively, provide vertical cross-sectional views of the array structure before and after loading of the jetting elements into vertical positions relative to a jetting surface, well walls, and laterally extending guidance tabs that inhibit lateral movement of the jets relative to the well walls beyond an amount predefined by the gaps between the jet walls and the end of the tabs while FIG. 8I3 provides an up-facing cut view of the structure along the cut line of FIG. 8I2.
FIGS. 8J1 and 8J2 provide two up-facing lateral views from the same perspective as noted in FIG. 8I3 but where the motion limiting/constraining tabs have different configurations as compared to those of FIGS. 8I1-8I3.
FIGS. 8K1 and 8K2 provide both a vertical cross-sectional view (FIG. 8K1) and an up-facing cut view along the cut line of FIG. 8K1 (FIG. 8K2) of an alternative embodiment where the movement limiting tabs of
FIGS. 8L1 and 8L2 provide both a vertical cross-sectional view (FIG. 8L1) and an up-facing cut view along the cut line of FIG. 8L1 (FIG. 8L2) of an alternative embodiment where the movement limiting spacers of FIGS. 8K1-8K2 have been shifted slightly upward away of the bottom of the jets and attached to the well walls instead of the jet walls wherein the spacers limit lateral jet and well movement to an acceptable amount.
FIGS. 8M1 and 8M2 are similar to that of FIGS. 8L1 and 8L2 but where the movement limiting spacers extend the entire height of the well walls and have modified lateral positions but still inhibit relative lateral motion to an acceptable level.
FIGS. 8N1 and 8N3 provide three views of another embodiment of a small array configuration where jets and wells are provided with elements for biasing movement of jets laterally toward the center of wells during vertical loading of the jets into the well walls wherein FIG. 8N1 provides an illustration of a side cross-sectional view of the jets prior to vertical loading into well walls and where the well walls include compliant or elastic tab elements that can contact the jet walls during loading to provide centering alignment by an excess biasing force being exerted by bending of the alignment tabs on either side when the jets are loaded closer to that side than the other side and wherein FIG. 8N2 provides a side cross-sectional view after loading and automatic lateral centering along with cutting/viewing direction line of FIG. 8N3, while FIG. 8N3 provides an up facing view of the lateral (XY) features of the array along the cut line of FIG. 8N2 as well as providing a cut line showing the relationship between the structure of
FIGS. 8O1-8O3 provide similar images to those provided in FIGS. 8N1-8N3 with the exception that the alignment tabs are attached to the jets as opposed to the well walls.
FIG. 9A1 provides a cross-sectional side view of a jetting/support structure and surrounding support flange where the support structure includes a pair of longitudinally extended elements (e.g., rings) that are radially separated by a radially extending spacer to provide improved compliance in the positioning of the jet relative to one or more mounting structures (not shown) that support the jet in the region of the outer flange with the jet able to have additional compliant behavior due to the rings and spacer while FIG. 9A2 provides a top view of the structure of FIG. 9A1.
FIGS. 9N1-9N3 provide cross-sectional side views of jetting/support structures similar to those of
FIG. 9O1 provides a schematic side view representation of cross-sections of four segments that can be conceptually combined to form a multi-jet array wherein a left segment is provided with a left side wall, two intermediate segments without side walls, and a right segment with a right side wall, wherein each segment includes a jetting base and a single jet similar to that of
FIG. 9O2 provides a schematic representation of the segments of FIG. 9O1 laterally shifted to depict the array resulting from the combination.
FIGS. 9Q1-9Q4 provide schematic side view representations of cross-sections of the jet array of FIG. 9O2 with addition of various well wall (or fin wall) configurations including various fluid flow and/or stress relief passages, wherein FIG. 9Q1 shows the well walls without lateral passages for either stress relief or fluid flow, FIG. 9Q2 shows the array with a single passage located between segments (i.e., four segments and thus three intermediate passages), FIG. 9Q3 shows a passage between the intermediate segments and the left and right side walls of the array, while FIG. 9Q4 shows that each segment includes a passage near but not at its own left and right ends.
FIGS. 9T1 and 9T2 provide segments similar to those of
FIGS. 10A1-10A3 provide three different cross-sectional side views during different states of the assembly of jetting structures and associated jetting side wall structures with a jetting base and associated base side wall structures.
FIGS. 10B1-10B3 provide three different cross-sectional side views during assembly of jetting structures and associated jetting side wall structures with a jetting base and associated base side wall structures similar to that of FIGS. 10A1 to 10A3 with the exception that the edges of the jetting side wall structures slide past deflectable, lateral, inward facing extensions or tabs attached to the base side walls to potentially aid in lateral or vertical alignment.
FIG. 11C1 provides a side cross-sectional view of a heat transfer array having two jets shown laterally displaced (with potentially additional jets located in front of and behind the cross-section of the page), a jetting surface, exit channels running between the sides of the jets and fin or well walls to a lateral running exit channel located above the well walls and running past an upper portion of the jets above which a single centrally located fluid entry port and a single, right side fluid exit port is shown.
FIGS. 11C2 and 11C3 show two lateral cross-sectional views taken from cuts C2 and C3 respectively of FIG. 11C1 wherein FIG. 11C2 shows not only vertical flow paths around each jet (by the dotted elements) but also a lateral flow path to right while FIG. 11C3 shows the primary flow paths as being vertical as the fluid is moving primarily upward in the channels surrounding individual jets (i.e. channels that are bounded by the well or fin walls and the jet walls).
FIG. 11E1 shows a vertical cross-sectional view of a heat transfer array or cold plate that looks similar to that of
FIG. 11F1 provides a vertical cross-sectional view of a cold plate including a heat transfer array similar to that of FIG. 11E1 along with a manifold structure located on top of a transfer array wherein the array includes the three vertical inlet splitting levels and where the heat transfer array and manifold structure are separated by a seal level while FIGS. 11F2 and 11F3 provide lateral cross-sectional cuts at levels F2 and F3, respectively, of FIG. 11F1.
FIGS. 35B1-35B2 provide a side view and top view of the well structure of
FIGS. 37A1-37G6 provide various views of a heat transfer array segment, or elements of such a segment, wherein the array structure only includes single stage (1×4) split along with a segmented well structure and a jetting surface structure.
FIGS. 38A1-38E12 provide various views of a four jet portion of a heat transfer array having two (1×4) vertical splitting levels along with a well structure and a jetting surface structure, or portions of such a four jet portion wherein the wells and jets are joined to each other along a substantial portion of their lengths with a gap and offset jetting surface contact structure at the bottom so as to force jetted fluid to move not only radially and vertically to an outlet passage but instead to move radially, vertically a short distance than circumferentially and then vertically again.
FIGS. 39A1-39E22 provide various views of a four jet portion of a heat transfer array having two (1×4) vertical splitting levels along with a well structure and a jetting surface structure, or portions of such a four jet portion, wherein the wells and jets are joined to each other via bridging element that is part of every other layer with successive bridges being circumferentially rotated so as to force jetted fluid to move not only radially and vertically to an outlet passage but instead to move radially and then back and forth vertically and circumferentially a number of times while traversing the height of the well or fin wall.
FIGS. 40A1-40G11 provide various views of a 16 jet portion of a heat transfer array having a single (1×4) vertical flow path split between an inlet and the jets and wherein above the split structure a compliance enhancing vertically extending recess exists in a connection plate that joins neighboring inlet and outlet openings to reduce a risk of thermal expansion differences resulting in damaging levels of stress being be transmitted between jets and well walls and or thermal expansion differences causing heat transfer efficiency losses as a result of jets and wells being misaligned.
FIGS. 41A1-41I11 provide various views of a 16 jet portion of a heat transfer array having a single (1×4) vertical flow path split between an inlet and the jets and wherein (1) above the split structure, a compliance enhancing vertically extending recess exists in a connection plate that joins neighboring inlet and outlet openings to reduce a risk of thermal expansion differences resulting in damaging levels of stress being transmitted between jets and well walls and/or thermal expansion differences causing heat transfer efficiency losses as a result of jets and wells being misaligned, (2) individual well jets are fixedly joined by a plurality of bridge elements (e.g. four) that extend the length of the wells other than at the junction of the jetting surface and the wells and that divide the post jetting path for each well into a plurality of isolated flow paths (e.g. four), (3) diagonal paths connecting the isolated post jetting flow paths from four wells to one another, and to one another, and (4) extended flow paths that join selected central portions of diagonal flow paths together that result in groups of wells having higher levels of stress separation from one another than do individual wells.
Electrochemical Fabrication in General
In some variations, the structure may be separated from the substrate. For example, release of the structure (or multiple structures if formed in a batch process) from the substrate may occur when releasing the structure from the sacrificial material particularly when a layer of sacrificial material is positioned between the first layer of the structure and the substrate. Alternative methods may involve, for example, the use of a dissolvable substrate that may be separated before, during or after removal of the sacrificial material, machining off the substrate before or after removal of the sacrificial material, or use of a different intermediate material that can be dissolved, melted or otherwise used to separate the structure(s) from the substrate before, during, or after removal of the sacrificial material that surround the structure(s).
Various embodiments of various aspects of the invention are directed to formation of three-dimensional structures from materials, some, or all, of which may be electrodeposited or electroless deposited (as illustrated in
The various embodiments, alternatives, and techniques disclosed herein may form multi-layer structures using a single patterning technique on all layers or using different patterning techniques on different layers. For example, various embodiments of the invention may perform selective patterning operations using conformable contact masks and masking operations (i.e. operations that use masks which are contacted to but not adhered to a substrate), proximity masks and masking operations (i.e. operations that use masks that at least partially selectively shield a substrate by their proximity to the substrate even if contact is not made), non-conformable masks and masking operations (i.e. masks and operations based on masks whose contact surfaces are not significantly conformable), adhered masks and masking operations (masks and operations that use masks that are adhered to a substrate onto which selective deposition or etching is to occur as opposed to only being contacted to it), and/or selective patterned deposition of materials (e.g. via extrusion, jetting, or controlled electrodeposition) as opposed to masked patterned deposition. Conformable contact masks, proximity masks, and non-conformable contact masks share the property that they are preformed and brought to, or in proximity to, a surface which is to be treated (i.e. the exposed portions of the surface are to be treated). These masks can generally be removed without damaging the mask or the surface that received treatment to which they were contacted or located in proximity to. Adhered masks are generally formed on the surface to be treated (i.e. the portion of that surface that is to be masked) and bonded to that surface such that they cannot be separated from that surface without being completely destroyed or damaged beyond any point of reuse. Adhered masks may be formed in a number of ways including: (1) by application of a photoresist, selective exposure of the photoresist, and then development of the photoresist, (2) selective transfer of pre-patterned masking material, and/or (3) direct formation of masks from computer-controlled depositions of material. In some embodiments, adhered mask material may be used as a sacrificial material for the layer or may be used only as a masking material which is replaced by another material (e.g., dielectric or conductive material prior to completing formation of a layer where the replacement material will be considered the sacrificial material of the respective layer. Masking material may or may not be planarized before or after deposition of material into voids or openings included therein.
Patterning operations may be used in selectively depositing material and/or may be used in the selective etching of material. Selectively etched regions may be selectively filled in or filled in via blanket deposition, or the like, with a different desired material. In some embodiments, the layer-by-layer build up may involve the simultaneous formation of portions of multiple layers. In some embodiments, depositions made in association with some layer levels may result in depositions to regions associated with other layer levels (i.e., regions that lie within the top and bottom boundary levels that define a different layer's geometric configuration). Such use of selective etching and/or interlaced material deposition in association with multiple layers is described in U.S. patent application Ser. No. 10/434,519, by Smalley, filed May 7, 2003, which is now U.S. Pat. No. 7,252,861, and which is entitled “Methods of and Apparatus for Electrochemically Fabricating Structures Via Interlaced Layers or Via Selective Etching and Filling of Voids”. This referenced application is incorporated herein by reference.
Temporary substrates on which structures may be formed may be of the sacrificial-type (i.e. destroyed or damaged during separation of deposited materials to the extent they cannot be reused) or non-sacrificial-type (i.e. not destroyed or excessively damaged, i.e. not damaged to the extent they may not be reused, e.g. with a sacrificial or release layer located between the substrate and the initial layers of a structure that is formed). Non-sacrificial substrates may be considered reusable, with little or no rework (e.g., by replanarizing one or more selected surfaces or applying a release layer, and the like) though they may or may not be reused for a variety of reasons.
Definitions of various terms and concepts that may be used in understanding the embodiments of the invention (either for the devices themselves, certain methods for making the devices, or certain methods for using the devices) will be understood by those of skill in the art. Some such terms and concepts are discussed herein while other such terms are addressed in the various patent applications to which the present application claims priority and/or which are incorporated herein by reference (e.g., U.S. patent application Ser. No. 16/840,305).
Thermal Control and Heat Transfer Arrays, Cold Plates, Systems, and Methods
In various embodiments of the invention, heat transfer arrays may be formed using the multi-layer, multi-material electrochemical methods, and other methods, set forth herein with any desired orientation relative to a stacking axis of the layers that form the device. However, in some embodiments, it is preferred that the formation orientation be such that the bottom part or bottom surface of the heat transfer array (i.e. the part in contact with or in closest proximity to the semiconductor device or other device or devices to be thermally managed) be formed parallel to the plane of the layers that are being stacked. In some embodiments, it is preferred that the primary jetting direction of fluid from the jetting structures be substantially perpendicular to the planes of the layers (i.e. substantially parallel to the stacking axis, i.e. preferable within 20 degrees of the stacking axis, more preferably within 10 degrees of the stacking axis, and even more preferable within 5 degrees of the stacking axis). In general, as used herein, the jetting direction is considered to be downward, regardless of the physical orientation of the jetting array during use. This terminology is not intended to convey a direction relative to a gravitational field unless specifically and unambiguously indicated as such. In some embodiments, the jets may have jetting directions that are intentionally not parallel to the stacking axis. In some embodiments, the heat transfer arrays may not have a bottom or at least may not have contiguous bottoms, but instead, the base of the array may be a semiconductor device (e.g. the back side of the wafer on which the active components are formed or a protective layer formed on the wafer material), other heat source, or other material or a material stack (not formed along with the other array structures) which act as an interface between the heat transfer array and the heat source. In some embodiments, the heat transfer array may have a rectangular configuration while in other embodiments, it may have a different configuration, e.g. a configuration that matches a shape and a size of a semiconductor chip or hot spots on the chip that are to undergo thermal management. In some embodiments, an individual heat transfer array may be formed as a single monolithic device while in other embodiments, heat transfer arrays may be formed as multiple elements that are bonded or otherwise joined one to another after formation. In some embodiments, multiple heat transfer arrays may be held apart from one another and even used in conjunction with multiple semiconductor devices. In some embodiments, heat transfer arrays may be formed with etching holes that allow removal of a sacrificial material after all layers have been formed or after formation of only a portion of the layers. Such etching holes may be filled in or sealed after the layer formation process or after etching but during the layer formation process. In other embodiments, a top or lid and/or base or bottom may be formed separately to allow efficient removal of sacrificial material. Other embodiments may not require special openings to remove sacrificial material. Various methods exist to handle sacrificial material removal and/or multi-component device assembly as are set forth in some of the patents and patent applications incorporated herein by reference.
Reference numbers are included in many of
FIG. 6D1 illustrates a side cross-sectional view of a portion of an HTA 610-D1 (which shows two jets 625, a cooling fluid impact surface 641 or jetting surface and a portion of a fluid return path 620 that moves fluid past the jets) wherein the cold plate 605 includes jets formed from a first material, well walls 656 formed from a second material, and an impact surface formed from a third material wherein the materials may be similar materials or different materials.
FIGS. 6D2-6D5 show top views of four different example configurations 610-D2 to 610-D5 that yield the same cross-sectional configuration illustrated in the structure 610-D1 of FIG. 6D1 showing fluid flow paths that might provide isolation of initial fluid return paths or connections between initial fluid return paths from different jets relative to one another (i.e., post jetting flow paths), wherein the fluid flow paths 620 remain isolated until the tops of the well walls are exceeded (FIG. 6D2), wherein each well of the left pair and of the right pair have a passage that joins them such that the combined return paths provide more surface area for fluid to extract heat from the solid walls of the wells or fin structures (FIG. 6D3), wherein pairs of individual jets 625 occupy combined well structures 655 (FIG. 6D4), or wherein the four individual return paths are joined to one another via crossed pairs of flow paths (FIG. 6D5).
FIG. 6E1 illustrates a side cross-sectional view of a portion of a heat transfer array or cold plate 610-E1 similar to that of FIG. 6D1 with the exception that the side-by-side pair of jets 625 shown have at least one common return path 620-V.
FIG. 6E2 to FIG. 6E7 illustrate six example top views 610-E2 to 610-E7 of the heat transfer array portion of FIG. 6E1 with each example providing a two-by-two array of jets and with each having a different jetting well configuration and/or well connections 655 that form part of post jetting group of fluid return paths with all sharing a common cross-sectional view as shown in FIG. 6E1 wherein FIG. 6E2 shows top and bottom side-by-side pairs having individual jetting wells 655 that are connected by a single relatively narrow fluid flow path that is similar to that of FIG. 6D3 but rotated by 90° about an axis perpendicular to a plane of the top view; FIG. 6E3 shows each of the upper and lower pairs of side-by-side jets 625 sharing a common well 655 similar to that of FIG. 6D4 but rotated by 90° about an axis perpendicular to a plane of the top view; FIG. 6E4 show that each jet 625 of the two-by-two array 640 has its own jetting well 655 but with a relatively narrow fluid flow path (e.g. having a width less than ¼ of the corresponding width of the well and perhaps even less than ⅛ of the well width) connecting the closest edges of the wells to their nearest neighbors such that four connection paths join the four wells together; FIG. 6E5 shows that the four wells 655 have similar connective paths as those shown in FIG. 6E4 but with the paths having moderate widths (e.g. between ¼ and ½ of the width of the individual wells) as opposed to relatively small widths; FIG. 6E6 illustrates a configuration where all four jets 625 share a single well 655 without any intermediate well wall or fin elements; and where FIG. 6E7 shows a configuration where all four jets 625 have their own wells 655 but with relatively narrow flow paths not only connecting nearest neighbors but also second nearest neighbors (i.e. the diagonal neighbors).
FIG. 6H1 illustrates jets 625 and wells 655 having different structural configurations from those shown in the previous examples wherein the wells are formed from neighboring hexagonal structures while jets are formed with spaced hexagonal structures, wherein the array includes five side-by-side jets, and wherein jetting from a single jet does not dispense fluid into a single well but into a plurality of wells (e.g. three wells) wherein portions of jet walls extend vertically into the wells while other portions of the jet walls contact the well walls or reside above the well walls while FIG. 6H2 illustrates a cut horizontal view of the array of FIG. 6H1 at cutline H2-H2 of FIG. 6H1, where it can be seen that the exemplified array not only has five side-by-side jets but has a total of three rows of jets, thus forming a 5×3 jet array 640, and wherein the well count is three times that of the jet count. In alternative embodiments, the array of jets and/or the array of wells may be formed with a combination of fitted hexagonal and triangular structures or structures with other polygonal or smooth surface configurations wherein the jets and the wells may have different configurations. In some variations, the jet walls may not extend into the well but end above the well walls.
While
FIG. 7A1 provides a vertical cross-section of part of a jetting array 740-A having a plurality of jets 725, a plurality of wells 755, and a jetting surface 741 wherein these three primary features may be formed from different materials and wherein some well walls include hollow regions 757 that may or may not allow fluid flow but can provide some level of stress relief during changes in temperature or when operational temperatures are significantly different from fabrication temperatures particularly when the well structure(s) or fins are formed from a different material than that of the jetting surface and especially material with different thermal coefficient of thermal expansion.
FIG. 7A2 provides a top view of the array 740-A of FIG. 7A1 where it can be seen that the array provides a 2×2 configuration of jets 725 and wells 755, the wells do not include fluid flow paths that connect them, and the hollow regions 757 shown in FIG. 7A1 do not extend to the top of the wells.
FIGS. 7A3 and FIG. 7A4 provide two cut views of the array 740-A of FIG. 7A2 illustrating two example hollow structure configurations wherein the hollow regions 757 of FIG. 7A3 are provided in the form of a number of discontinuous segments that form a grid pattern bisecting the well walls 756 or fin structures around the well depressions while FIG. 7A4 provides a similar pattern of hollow regions 757 but with the paths being continuous in nature as opposed to being discontinuous.
FIGS. 7B1-7B4 provide cross-sectional views of part of a jetting array 740-B having hollow regions 757 within portions of the fin or well walls 756 as did FIGS. 7A1-7A4 but with those hollow regions having a different configuration relative to those of FIGS. 7A1-7A4, wherein FIG. 7B1 provides a vertical cross-section (in an X-Z plane) showing that in the plane of the cross-section hollow regions exist within the outer well walls 756-O but not in the central well wall 756-C, while FIGS. 7B2 and 7B3 provide cut views of the array 740-B of FIG. 7B1 along cut lines 7B2-7B2 and 7B3-7B3 respectively, and FIG. 7B4 provides a cross-section view along cut line of 7B4-7B4 of FIG. 7B3.
In contrast to
FIGS. 8A1 and 8A2, respectively, provide a vertical cross-section view in an X-Z plane and a cut view in an X-Y plane looking upward along the Z axis wherein jet walls 835, jet flow paths 820, jetting surface(s) 841, and solid elements 845-J that vertically join the bottom of the jet walls to the jetting surface exist, wherein the solid elements convert the jetting functionality to a combined jetting and fin functionality (i.e., the combined jet and solid elements, or finjets, take on a dual jetting and a solid heat conduction or fin functionality). Different features of the array are shown with different hatching patterns to illustrate that they may be formed from different materials. The solid conductive elements or connective elements 845-J that join the jet walls 835 and the jetting surface 841 are shown having a width that is narrower than that of the jet walls themselves. In other embodiments, the connective elements and the fins may be formed of the same material and/or they have the same widths or the connective elements may be wider than the jet walls, while in other embodiments, other configurations may exist.
FIGS. 8B1 and 8B2, provide examples of the heat transfer array configuration 810 of FIGS. 8A1 and 8A2 in two different states of formation according to another embodiment of the invention wherein FIG. 8B1 shows the jetting surface 841 and the well walls 856 formed separately from the jets 825 and the connective elements 845-J while FIG. 8B2 shows the state of the process after the two portions are vertically shifted to form the complete array of FIGS. 8A1 and 8A2. In some variations, the connective elements may be bonded to the jetting surface while in other embodiments, they may only be contacted. In still other embodiments, other formation methods may be used including, for example: (1) other assembly methods, (2) formation in a final configuration, without assembly using an electrochemical fabrication method or other method, and (3) formation of jets, connective elements, and well walls together followed by subsequent bonding or contacting to a jetting surface.
FIGS. 8C1 and 8C2 are similar to FIGS. 8A1 and 8A2 with the exception that the connective elements 845-J that join the jets 825 and the jetting surface 841 are wider than the jet walls 835 themselves and provide contact to the well walls 856 in addition to the jetting surface 841. In FIG. 8C2, it can be seen that the connective elements 845-J do not provide a ring-like structure as do the jet walls 835 but instead define discrete contact regions around which jetted fluid can flow or leave the jet. In other embodiments, other configurations are possible including the jets, the well walls, and the connective elements all being formed from the same material.
FIGS. 8D1 and 8D2 are also similar to those of FIGS. 8A1 and 8A2 with two exceptions: (1) the narrower connective elements 845-J are individually centered relative to the jet walls 835 that they contact and (2) instead of just two elements bridging the jetting gap between each jet and the jetting surface (i.e. bridging the vertical or Z direction distance between the lower portion of the jet and the jetting surface), four connective elements are used. In other embodiments, different numbers of connective elements may be used and/or the bridging elements may have different configurations or be located in different positions.
FIGS. 8E1 and 8E2 respectively illustrate a jet-well-bridge configuration that may be assembled. FIG. 8E1 provides both a vertical cross-sectional view (upper portion of the figure) and a downward looking cut view (lower portion of the figure) while FIG. 8E2 provides a vertical cross-sectional fully assembled view wherein the connective elements 845-W are provided with a pattern that allows placement of the jets 825 using an assembly process that provides reasonable positioning but not necessarily highly precise positioning that will always result in appropriate vertical support for the jets along with adequate jetting, connecting, and post jetting flow paths even without perfect lateral alignment of the jets 825 and the wells 855. In other embodiments, other configurations may be used that provide for both improved assembly and desired jet to connective elements placement.
FIGS. 8F1 and 8F2 provide views of another jetting array configuration 840-F but with a different type of bridging structure or connective elements 839 that join the jets 825 to the well walls 856 as opposed to joining or contacting the jets to the jetting surface 841 (as was shown in FIGS. 8A1 to 8E2) wherein FIG. 8F1 provides a vertical cross-sectional view and FIG. 8F2 provides an upward looking horizontal, or lateral, cut view along the cut line in FIG. 8F1 wherein the connective elements 839 provide for a desired lateral alignment of the jets 825 and the well walls 856, may also provide for retained vertical alignment along (e.g. when the connective elements are bonded to, or formed monolithically) with the jets and the well walls, and may also provide improved stress tolerances during temperature variations (e.g. during use vs. non-use) particularly when the jetting surface and the well walls or jets are made of different materials with different coefficients of thermal expansion (CTEs), and wherein a single bridging element 839 is provided for each jet. In other embodiments, other bridging structure configurations are possible.
FIGS. 8G1 and 8G2 provide views of another jetting array configuration 840-G with bridging structures or connective elements 839 similar to those of FIGS. 8F1 and 8F2 that join the jets 825 to the well walls 856 but where one jet of the pair has two such bridging structures 839 oriented along one lateral axis while the other has two bridging or connective elements 839 oriented along a perpendicular lateral axis as can be seen in FIG. 8G2. In other embodiments, other configurations are possible and include bridging elements oriented along different axes, bridging elements located at different vertical heights, and even bridging elements connecting only some jet walls to well walls and not others (especially when the jets themselves are connected to one another at their upper ends (not shown in the present example as may be the case when jets are part of a branched or splitting network).
FIGS. 8H1 and 8H2 provide views of a jetting structure 840-H in a preassembly state and a post assembly state, respectively. In FIG. 8H1 a jetting surface 841 and well walls 856 are shown laterally aligned but vertically (or longitudinally) separated from the jets 825 and bridging elements 839 (FIG. 8H1) and jetting surface 841, well walls 856, jets 825 and bridging elements 839. FIG. 8H2 shows the components after assembly from both a cross-section vertical perspective (lower portion of FIG. 8H2) and a top view (upper portion of FIG. 8H2). Prior to assembly, the well walls 856 and the jetting surface 841 are mated or formed together as are the jets 825 and the bridge elements 839 wherein the bridge or connective elements 839 are configured to engage the tops of the well walls 856. In this type of configuration, as that of FIGS. 8G1 and 8G2, enhanced stress reduction across larger array configurations may be provided. In other variations, the well walls and the connective elements provide not only constraints on positioning along perpendicular axes, but they may also provide configurations, such as notches in the well walls or additional tabs below the connective elements to provide rigid or more compliant constraints on relative lateral movement. In some variations, vertical movement constraints and/or horizontal movement constraints may not be provided on every jet or well wall but only on selected jets and well walls to meet both positioning and compliance requirements.
FIGS. 8I1-8I3 provide three views of another embodiment of a small heat transfer array 810-I where jets 825 and wells 855 are provided with elements 848-T for constraining excess movement while still allowing some movement wherein FIGS. 8I1 and 8I2 provide vertical cross-sectional views of the array structure before (FIG. 8I1) and after (FIG. 8I2) loading of the jetting elements into vertical positions relative to a jetting surface 841, well walls 856, and laterally extending spacers or tabs 848-T that inhibit lateral movement of the jets relative to the well walls beyond an amount predefined by the gaps between the jet walls and the end of the tabs while FIG. 8I3 provides an up-facing cut view of the structure along the cut line of FIG. 8I2.
FIGS. 8J1 and 8J2 provide two up-facing lateral views from the same perspective as noted in FIG. 8I3 but where the motion limiting/constraining tabs 848 have different configurations as compared to those of FIGS. 8I1-8I3.
FIGS. 8K1 and 8K2 provide both a vertical cross-sectional view (FIG. 8K1) and an up-facing cut view along the cut line of FIG. 8K1 (FIG. 8K2) of an alternative embodiment where the movement limiting tabs of
FIGS. 8L1 and 8L2 provide both a vertical cross-sectional view (FIG. 8L1) and an up-facing cut view along the cut line of FIG. 8L1 (FIG. 8L2) of an alternative embodiment where the movement limiting spacers 848-W of FIGS. 8K1-8K2 have been shifted slightly upward away of the bottom of the jets 825 and attached to the well walls 856 instead of the jet walls 835 wherein the spacers may limit lateral jet and well movement to an acceptable amount.
FIGS. 8M1 and 8M2 are similar to that of FIGS. 8L1 and 8L2 but where the movement limiting spacers 848-W extend the entire height of the well walls 856 and have modified lateral positions but still inhibit relative lateral motion to an acceptable level. In some alternative embodiments, the spacers may be limited to more than half the height of the well walls but less than their whole height while in other embodiments, they may be limited to fractions of the height of the well walls, e.g. less than 1/10, less than ⅕, less than ⅓ or less than ½. In still other embodiments, spacers may be located at different vertical heights and even in a stacked manner with intermediate flow paths which force the vertical flow from jetting surface to the upper surface of the well to take on a lateral flow component (e.g. in a radial direction or in a circumferential direction) to cause breakup of the laminar flow in favor of turbulent flow to cause additional heat transfer from the well or fin walls to the flowing fluid.
FIGS. 8N1 and 8N3 provide three views of another embodiment of a small array configuration where jets 825 and wells 855 are provided with elements 847-W for biasing movement of jets laterally toward the center of wells during vertical loading of the jets into the well walls wherein FIG. 8N1 provides an illustration of a side cross-sectional view of the jets prior to vertical loading into well walls and where the well walls include compliant or elastic tab elements 847-W that can contact the jet walls 835 during loading to provide centering alignment by an excess biasing force being exerted by bending of the alignment tabs 847-W on either side when the jets are located closer to one side than the other side and wherein FIG. 8N2 provides a side cross-sectional view after loading and automatic lateral centering along with cutting/viewing direction line of FIG. 8N3. FIG. 8N3 provides an up facing view of the lateral (XY) features of the array along the cut line of FIG. 8N2 as well as providing a cut line showing the relationship between the structure of FIG. 8N3 and the cross-sectional view of FIG. 8N1. The elastic/compliant nature and the length of the tabs 847-W of FIGS. 8N1-8N3 provide guided loading along with guided alignment and potentially position maintenance as well as a heat flow connection between the well walls and the jet walls along with providing flow path splitting elements that may lead to enhanced turbulent flow and heat transfer. In other embodiments, fewer tabs may be provided while in still other embodiments, additional tabs may be provided that may or may not force or encourage additional lateral (e.g. circumferential) flow along the primary vertical flow path. In some embodiments, the tabs may induce a clockwise or counterclockwise flow in the fluid as it proceeds from the bottom of the well walls to the top of the well walls.
FIGS. 8O1-8O3 provide similar images to those provided in FIGS. 8N1-8N3 with the exception that the alignment tabs 847 are attached to the jets 825 as alignment tabs 847-J as opposed to being attached to the well walls 856. In other embodiments, other alignment tab configurations may be used to obtain similar functionality as well as additional functionalities such as vertical positioning of the jets relative to the well walls or jetting surface. For example, in some such alternatives, tabs may be provided on both the jets and the well walls while in other alternatives, some tabs may provide for contact and deflection upon loading while other tabs may not. Some tabs may simply function as lateral movement stops and or turbulent flow enhancers.
While FIGS. 8A1-8O3 have illustrated various examples of tabs, spacers, alignment structures and flow diverters, still other alternatives exist and may be implemented in other embodiments for one or more different purposes. These features may be implemented individually or in combination on larger arrays, in selected areas of larger arrays, or for selected groups of jets or wells on larger arrays. In some embodiments, one or more of these features may be implemented in conjunction with other feature enhancement discussed herein. The features of any of FIGS. 8A1-8O3 may be primarily provided, for example, for stress relief purposes while in other embodiments, the features may be implemented to maintain a desired level of flow uniformity or flow disparity between various jets, while in other embodiments, a combination of these purposes may be the motive for implementation.
FIG. 9A1 provides a cross-sectional side view of a jetting/support structure 937-A and surrounding support flange 937-F where the support structure 937 includes a larger width plate or disk-like structure and a smaller width plate or disk-like structure separated by a pair of longitudinally extended elements 937-V (e.g., in this embodiment, they are rings) that are radially separated by a radially extending spacer 937-H to provide improved compliance in the positioning of the jet 925 relative to one or more mounting structures (not shown) that support the jet in the region of the outer flange 937-F with the jet able to have additional or enhanced compliant behavior due to the rings 937-V and spacer 937-H while FIG. 9A2 provides a top view of the structure 937 of FIG. 9A1. In other embodiments, the plate or disk-like structures, the flange, the support structure, the rings and spacer, and/or the jet configuration may take other forms such as, for example, circular or other smooth curved configurations, or other polygonal configurations. The rings and spacer may have different longitudinal heights, different radial spacing, and even sloped or stair-stepped configurations.
FIGS. 9N1-9N3 provide cross-sectional side views of jetting/support structures 937-N similar to those of
FIG. 9O1 provides a schematic side view representation of cross-sections of four segments that can be conceptually combined to form a multi-jet array 940 wherein a left segment is provided with a left side wall, two intermediate segments without side walls, and a right segment with a right side wall, wherein each segment includes a jetting base 941 and a single jet 925 similar to that of
FIG. 9O2 provides a schematic representation of the segments of FIG. 9O1 laterally shifted to depict the array 940 resulting from the example combination.
FIGS. 9Q1-9Q6 provide schematic side view representations of cross-sections of the jet array 940 of FIG. 9O2 with addition of various well wall 956 (or fin wall) configurations including various fluid flow 920 and/or stress relief passages 957, wherein FIG. 9Q1 shows the well walls without lateral passages for either stress relief or fluid flow, FIG. 9Q2 shows the array with a single passage located between segments (i.e., four array segments and thus three intermediate passages), FIG. 9Q3 shows a passage between the two intermediate array segments and the left and right side walls of the array (i.e. in some well walls but not in all well walls), FIG. 9Q4 shows that each array segment includes a passage near but not at its own left and right ends, thus resulting in two passages in some of the well walls or fin elements, FIG. 9Q5 shows well and passage configurations similar to that of FIG. 9Q4 but with the exception that the lower ends of the jet walls are joined to well walls via bridging elements; while FIG. 9Q6 depicts wells with passages but with passages in the well walls capped such that the passages may remain fluid free, hold a different fluid or other material, or allow fluid to flow via entrance and exit regions (not shown), thus resulting in two passages in some of the well walls or fin elements, FIG. 9Q5 shows well and passage configurations similar to that of FIG. 9Q4 but with the exception that the lower ends of the jet walls are joined to well walls via bridging elements; while FIG. 9Q6 depicts wells with passages but with passages in the well walls capped such that the passages may remain fluid free, hold a different fluid or other material, or allow fluid to flow via entrance and exit regions (not shown).
FIGS. 9T1 and 9T2 provide segments similar to those of
FIGS. 10A1-10A3 provide three different cross-sectional side views during different states of the assembly of a small array. In FIG. 10A1, jetting structures 1025 with associated jetting guidance structures 1035-G are provided along with separate jetting base 1041 with associated well walls and guidance structure 1056-G wherein the state of the process is shown prior to deforming the jetting guidance structures 1035-G and prior to bringing the jetting structures 1025 and the base or well structure 1055 vertically together. FIG. 10A2 shows the state of the process after bending the jetting guidance structures 1035-G laterally inward to form sloped jetting guidance structures that can be aligned and inserted into an opening defined by the base or well guidance structures 1056-G so as to provide fine lateral alignment of the jetting and base or well structures when vertical shifting occurs. FIG. 10A3 shows the state of the process after vertically shifting the positions of the jetting structures 1025 with respect to the base or well structures 1055 and with such shifting being accompanied by one or more of: (1) enhanced lateral positioning of the jets and the well structures due at least in part to the sloped configuration of the jetting guidance structures, (2) the vertical positioning of the jetting structures and jetting guidance structures being at least partially dictated by the increased lateral width of the jetting guidance structures relative to the lateral width of the base or well guidance structures as vertical insertion occurs, and/or (3) ease of at least initial vertical insertion resulting from the sloped configuration of the jetting guidance structures.
FIGS. 10B1-10B3 provide three different cross-sectional side views showing various states of assembly of jetting structures 1025 and associated jetting guidance structures 1035-G with a jetting base 1041 and associated base or well guidance structures 1056-G similar to that of FIGS. 10A1 to 10A3 with the exception that the edges of the jetting guidance structures 1035-G slide past deflectable, lateral, inward facing, potentially elastic extensions or tabs 1047-G attached to the base or well guidance structures 1056-G to potentially aid in lateral or vertical alignment.
FIGS. 10A1-10B3 provided two examples of how assembly processes may be facilitated by use of sloped features and/or deflectable elements or elastic elements. Such enhancements may be implemented in different manners as will be apparent to those of skill in the art upon review of the teachings herein and may be applied to the formation of arrays of different sizes, different jet and well configurations. In some embodiments, the separate guidance structures may be merged with well walls and/or jets. In some embodiments, the guidance structures may also function as sealing elements and/or heat transfer elements.
FIG. 11C1 provides a side cross-sectional view of a small heat transfer array 1110 having two jets 1125 shown laterally displaced with potentially additional jets located in front of and behind the cross-section of the page, a jetting surface 1141, exit channels 1158-V running between the sides of the jets and fin or well walls 1156 to a lateral running exit channel 1158-A located above the well walls and running past an upper portion of the jets above which a single centrally located fluid entry port 1117 and a single, right side fluid exit port 1119 is shown.
FIGS. 11C2 and 11C3 show two lateral cross-sectional views taken from cuts C2 and C3 respectively of FIG. 11C1 wherein FIG. 11C2 shows not only vertical flow paths 1120-V around each jet 1125 (by the dotted elements which were out of the plane of the page in FIG. 11C1 but are within the plane of the page in this figure) but also a lateral flow path 1120-W to right while at the cross-sectional position of C3-C3 as shown in FIG. 11C3, the primary flow paths are vertical as the fluid is moving primarily upward in the channels 1158-V surrounding individual jets 1125 (i.e. channels bounded by the well or fin walls and the jet walls).
FIG. 11E1 shows a vertical cross-sectional view of a heat transfer array 1110-E or cold plate that looks similar to that of
FIG. 11F1 provides a vertical cross-sectional view of a cold plate 1105-F including a heat transfer array 1110-F below the seal level 1169-L similar to that of FIG. 11E1 along with a manifold structure 1115 located on top of a transfer array that includes the three vertical inlet splitting or staging levels 1117-S where the heat transfer array and manifold structure are separated by a seal 1169 at level 1169-L while FIGS. 11F2 and 11F3 provide lateral cross-sectional cuts at level F2 and F3 of FIG. 11F1. In some variations of the embodiments of
While
Arrows in
In some embodiments, the array of
In some preferred embodiments, though not necessarily all embodiments, the jetting structures also act as fins, or worded another way, some of the fin structures have embedded jets. In the depicted embodiments, the jetting impact surfaces are closer to a heat source surface (e.g. a semiconductor surface or other heat source surface) than is the primary exit path, channel, or level. These jetting surfaces may be considered to be located at the bottom of jetting wells with each jet having its own well and with the fluid exit path being above the floor of the jetting wells. In some embodiments, it is possible to have multiple jets (e.g. 2, 3 or 4 jets) share a jetting well while still having the primary fluid exit path being above the floor of the jetting wells. In some embodiments, the lower surface of the jet side walls (excluding bridging material that provides fin functionality) is located below (i.e. closer to the floor of the jetting wells than is the primary fluid exit channel) while in other embodiments, the lower extent of the jet side walls may be located above a primary fluid exit channel.
In some embodiments, jetting may occur directly on a heat source surface (e.g. a silicon or other surface of the semiconductor that is being cooled) while other embodiments may jet onto a floor of the transfer array which has been bonded to the semiconductor surface or to an independent jetting surface that has been transferred to the semiconductor surface or deposited directly thereon. Such an independent jetting surface may be located only in jetting well regions, in portions of jetting wells where substantially perpendicular impact of jetted fluid is to occur (e.g. within 15 degrees of perpendicular, within 10 degrees, within 5 degrees, or even within 1 or 2 degrees) or may be located as a complete coating applied to the semiconductor surface. In some embodiments, the semiconductor surface may be the back side of a semiconductor (i.e. the side opposite to where semiconductor device formation occurs). In some embodiments, the semiconductor surface may undergo etching or planarization to reduce its thickness prior to locating, applying or forming the transfer array (i.e. the microchannel, microjet array) thereon. In some embodiments, the reduction in thickness may be uniform while in other embodiments, the reduction in thickness may be non-uniform and may actually be used to form flow channels or jetting wells that may be used by the transfer array. In some embodiments, thinning may be followed by deposition of one or more materials to provide enhanced surface properties. In some embodiments, for example, semiconductor thickness may start in the range of 500-700 microns (ums) and be thinned to 400 microns, 300 microns or even less. In some embodiments, mounting the transfer array onto the semiconductor may occur by direct bonding, clamping the devices together with an intermediate thermal transfer material (e.g. solid or flowable) that may provide some thermal expansion stress relief. In still other embodiments, bonding or attachment to a semiconductor may not occur, but instead, the cooling device may be bonded or attached to another part of a semiconductor package such as a PCB, a PWB, or an integrated heat spreader (IHS) to which the semiconductor device is attached. Some embodiments that make use of an intermediate thermal grease may target a thickness of between 25-50 microns while bonding that occurs via solder may target solder thicknesses in the range of 25-75 microns. Some embodiments may use o-ring seals, solder, or other sealants when bringing separately formed elements into hermetic configuration. Some embodiments may make use of ultrasonic or diffusion bonding to ensure proper sealing.
In some embodiments, jets may change dimensions vertically along the flow path (e.g. by widening or narrowing at desired locations). In some embodiments, small corner regions may be filled in to minimize locations where fluid stagnation or low flow may exist so as to further enhance heat transfer. Such regions may exist in the inlet layer, the exit layer, or even the regions where well floors and well walls meet. In other embodiments, surface texturing may be added to key heat transfer regions to further enhance surface area contact and thus heat transfer.
In other embodiments, variations of the configurations shown in
In some embodiments, not shown, instead of a single elevated lip around the channel openings of the micro array, multiple concentric lips, or lips of other configurations may be formed on the micro-array surface and possibly one or more corresponding notches formed in the bonding surface of the header or manifold such that upon mounting and flowing of a bonding agent, some overlap or interlacing of surface features occurs. In some embodiments, the micro-array may be made to have recesses while the header may be made to have or more protrusions. In some embodiments, the regions between all successive lips may be filled with bonding or sealing material, while in other embodiments, only regions between a portion of the lips may receive bonding or sealing material. In some embodiments, the header may be formed in any of a variety of ways (e.g. by molding or by CNC machining) from aluminum, copper or any other suitable material. The heat transfer array or portions of the array may also be formed in a number of different manners such as by electrochemical multi-material, multi-layer methods as set forth herein. The array may be formed from a plurality of multi-material layers (including one or more structural materials on each layer and one or more sacrificial materials on each layer where the structural or sacrificial materials may be different on different layers). Structural materials may include, for example, nickel cobalt for strength, rhodium for wear resistance, copper for enhanced heat flow, palladium for strength or enhanced wettability, tungsten titanium (TiW) or epoxy or other material for use as a solder mask, a solder flux, or other bonding material or bonding promoter deposited as part of the layer formation process. Seed layers and dielectric materials (e.g. plastics or ceramics) may also be incorporated into the formation process as desired.
FIGS. 33F1, 33F2, and 33G provide isometric views of the three primary elements of the heat transfer array 3310: (1) the array of jets 3340 and associated inlet ports and vertical splitting levels, (2) the wells 3355 and associated well walls (or fins) 3356 into which the jets are positioned while in an operational state, and (3) a substrate or component which provides a jetting surface 3341 or surface that is the direct recipient of fluid which is expelled from the jetting orifices, wherein the jetting surface is separated from the jets and wells in the partially exploded view of FIG. 33F1, the jets are separated from the wells and jetting surface in the partially exploded view of FIG. 33F2, and all three elements are shown separated in the fully exploded view of
FIGS. 33K1-33K2 provide two different isometric views of the jetting and inlet structure 3315 of the heat transfer array (or array portion) 3310 of
FIGS. 33K4-1 to 33K4-8 each provide four different views of the jetting and inlet structure 3315 at different states in the process of forming the structure from the buildup of the eight stacked layers shown in FIG. 33K3, wherein the “−1” figure shows state after formation of the first layer, the “−2” figure shows state after formation of the second layer, and so on for each of the “−3” to “−8” figures, and wherein (a) an upper most portion of each figure provides a top view of the structural material portion of the just formed layer, (b) the next lower portion provides a side view of the structural material portion of the just formed layer, (c) the next lower portion provides a side view of the structural material of the already formed stack of layers, and (d) the lowest portion provides an isometric view of the structural material of the already formed stack of layers. From these figures, the channeling that provide fluid flow paths to and through the jet can readily be seen and understood by those of skill in the art.
FIGS. 33L1-33L3 shows various views of the well structure 3356 of the array of
FIGS. 33M1-33M2 shows various views of the jetting surface structure 3341 of the array 3310 of
FIGS. 35B1-35B2 provide a side view and top view of the well structure 3556 of
FIGS. 37A1-37A6 provide a number of views of a heat transfer array segment 3710 wherein the array structure only includes single stage (1×4) split along with segmented well structure 3756 and a jetting surface structure 3741 with FIGS. 37A1 and 37A2 showing an isometric view and a top view of the structure in a first rotational orientation (about a vertical axis or Z axis that extends in a layer stacking direction), while FIGS. 37A3 to 37A5 show the same structure as that of FIG. 37A1 but at different vertical orientations whereby by combination of the four illustrated views would provide a complete inlet and associated 16 jetting structures, and wherein the FIG. 37A6 shows the structure tilted so that the bottom of the jetting surface structure can be seen.
FIGS. 37B1-37B6 provide similar views to those shown in FIGS. 37A1-37A6 with the exception that the jetting surface structure has been removed so as to better illustrate the relationship between the jets 3725 and the wells 3755 wherein a recession of the bottom of the jets compared to the bottom of the wells can be seen in FIG. 37B6, the lack of inward facing protrusions on wells can be more clearly seen as compared to those existing in
FIGS. 37C1-37C6 provide similar views to those shown in FIGS. 37A1-37A6 and 37B1-37B6 with the exception that only the jetting structure and inlet path structure 3715 is shown.
FIGS. 37D1-37D2 illustrate the top and bottom views, respectively, of a combination of the four structural elements of FIGS. 37A1, 37A3, 37A4, and 37A5 that produce an array 3710-D with a single full inlet, four partial outlets at the corners, and total of 16 jets.
FIGS. 37E1-37E2 illustrate top and bottom views, respectively, of four copies of the combination of the four structural elements of FIGS. 37A1, 37A3, 37A4, and 37A5 as used to produce a heat transfer array or partial heat transfer array 3710-E with one full center outlet, four full intermediate inlets, four edge half outlets, and four corner quarter edge outlets, along 64 jets, 64 wells and associated connection paths.
FIGS. 37G1 to FIG. 37G6 each provide four different views of the jetting and inlet structure 3715 at different states in the process of forming the structure from the buildup of the six stacked layers shown in
FIGS. 38A1-38A4 provide four different isometric views of a four jet portion of a heat transfer array 3810 having two (1×4) vertical splitting levels along with a well structure 3856 and a jetting surface structure 3841 wherein the wells and jets are joined to each other along a substantial portion of their vertical lengths with a gap and offset jetting surface contact structure at the bottom so as to force jetted fluid to move not only radially and vertically to an outlet passage but in addition, to move radially, vertically a short distance than circumferentially, and then vertically again (e.g. to provide more forced fluid to fin contact and thus more heat transfer).
FIGS. 38C1-38C4 show several isometric views of portions of a jetting structure 3835 including structural elements 3839 that form a bridge between a circular jet wall and a circular well wall.
FIGS. 38E1-38E12 each provide four different views of the structure 3810 of
FIGS. 39A1-39A4 provide four different isometric views of a four jet portion of a heat transfer array 3910 having two (1×4) vertical splitting levels along with a well structure 3956 and a jetting surface structure 3941 wherein the wells 3955 and jets 3925 are joined to each other via bridging element 3939 that is part of every other layer with successive bridges being circumferentially rotated (i.e. rotated in Θ in a R, Θ, Z coordinate system centered on the middle of a jet, where Z extends along the build axis) so as to force jetted fluid to move not only radially and vertically to an outlet passage but instead to move radially and then back and forth vertically and circumferentially a number of times while traversing the height of the well or fin wall (e.g. to provide more forced fluid to fin contact and possibly more turbulent flow and thus more heat transfer).
FIGS. 39C1-39C4 provide a top view (FIG. 39C1) and several isometric views of a jetting structure 3935 including structural elements 3939 that form a bridge between a circular jet wall and a circular well wall where the back and forth rotation of the bridge elements can be seen. The depiction in FIGS. 39C1 to 39C4 is somewhat artificial and that the bridging elements are no more part of the jet structure than the well structure but instead all three configurations are part of a single monolithic structure.
FIGS. 39E1-38E22 each provide four different views of the structure 3910 of
FIGS. 40A1-40A2 provide two different isometric views of a 16 jet portion of a heat transfer array 4010 having a single (1×4) vertical flow path split between an inlet and the jets 4025 and wherein above the split structure a compliance enhancing vertically extending recess (or ring like notch or channel) exists in a connection plate 4037 that supports the jets 4025 and that joins neighboring inlet 4017 and outlet 4019 openings to reduce a risk of thermal expansion differences resulting in damaging levels of stress being transmitted between jets and well walls and/or thermal expansion differences causing heat transfer efficiency losses as a result of jets and wells being misaligned.
FIGS. 40B1 and 40B2 provide different isometric views of the jet and inlet path structure 4015 of FIGS. 40A1 and 40A2.
FIG. 40C1 provides an isometric view of the well structure 4056 of FIGS. 40A1 and 40A2 while FIG. 40C2 provides a top view of the well structure with its diagonal flow paths 4020-W connecting the wells 4055 diagonally.
FIGS. 40F1 and 40F2 provide an isometric view of the heat transfer array portion 4010 shown in FIGS. 40A1 and 40A2 along with the mounted jetting surface structure 4037 while FIG. 40F2 provides a side view of the structure 4010 of FIG. 40F1 along with dimensional labels.
FIGS. 40G1-40G11 each provide four different views of the structure 4010 of
FIGS. 41A1-41A2 provides two different isometric views of a 16 jet portion of a heat transfer array 4110 having a single (1×4) vertical flow path split between an inlet and the jets 4125 and wherein (1) above the split structure, a compliance enhancing vertically extending recess exists in a connection plate 4137 that supports the jets 4125 and that joins neighboring inlet 4117 and outlet 4119 openings to reduce a risk of thermal expansion differences resulting in damaging levels of stress being transmitted between jets and well walls and/or thermal expansion differences causing heat transfer efficiency losses as a result of jets and wells being misaligned, (2) individual well jets 4125 are fixedly joined by a plurality of bridge elements 4138 (e.g. four) that extend the length of the wells 4155 other than at the junction of the jetting surface and the wells and that divide the post jetting path for each well into a plurality of isolated flow paths (e.g. four), (3) diagonal paths 4120-W connecting the isolated post jetting flow paths from four wells to one another, and to one another, and (4) extended flow paths 4120-W that join selected central portions of diagonal flow paths together that result in groups of wells having higher level of stress separation from one another than do individual wells.
FIGS. 41F1 and 41F2 provide an isometric view of the structure 4115 of
FIGS. 41H1 and 41H2 respectively provide an isometric view and a side view of the structure 4110 of FIGS. 41A1 and 41A2 combined with the jetting structure of
FIGS. 41I1-41I11 each provide four different views of the structure of FIGS. 41H1 and 41H2 including the jetting and inlet structure 4115, the well structure 4156, and jetting surface structure 4141 (as appropriate) at different states in the process of forming the structure from the buildup of the eleven stacked layers shown in FIG. 40H2, wherein the “I1” figure shows state after formation of the first layer, the “I2” figure shows state after formation of the second layer, and so on for each of the “I3” to “I11” figures, and wherein (a) an upper most portion of each figure provides a top view of the structural material portion of the just formed layer, (b) the next lower portion provides a side view of the structural material portion of the just formed layer, (c) the next lower portion provides a side view of the structural material of the already formed stack of layers, and (d) the lowest portion provides an isometric view of the structural material of the already formed stack of layers.
In some embodiments, devices (e.g. microjet and microchannel portions of the cold plate, i.e. the heat transfer array portion) may be fabricated by an additive layer process such as a multi-layer, multi-material process as set forth herein. Such devices may undergo post processing treatment or undergo one or more breaks in the middle of layer processing to modify the structural or surface configuration of the structures being formed or to apply additional processing steps that might not be effectively implementable after layer formation is complete (e.g. use of a high pressure abrasive particle flow to smooth sharp corners in fluid channels, application of coatings or surface treatments while access to such surfaces is not blocked by material forming subsequent layers, use of partial sacrificial material removal processes to make post layer formation of sacrificial material easier).
Some alternative embodiments may be created by selecting features associated with one or more embodiments or aspects and combining them with one or more features from one or more other embodiments or aspects.
Features of some embodiments include: (1) heat transfer arrays with multilevel microchannels that are integrated with microjet arrays where the two elements are connected via multiple levels to maximize heat transfer capability and efficiency; (2) corrosion and erosion may be minimized by using high strength electrodepositable materials (e.g. nickel cobalt (NiCo), palladium, rhodium, or the like in selected areas); (3) corrosion and erosion may be minimized or at least effectively managed by local thickening at impingement areas; (4) dimensions of features in a heat transfer array may be uniquely optimized for fluid flow, for example, slot jet dimensions and fin dimensions may vary from jet-to-jet and from inlet-to-outlet to optimize or at least bring heat transfer to a desired level of efficiency or effectiveness; and (5) heat transfer arrays and cold plates may be optimized to the unique requirements of specific heat sources by changing dimensions, directions of fluid flow, locations of inlets and outlets, and the like. In some embodiments, the fluid impingement surface or surfaces struck by flow from jets may act as the largest single area or areas of heat transfer while not necessarily providing for the majority of the heat transfer. For convenience, such area or areas may be termed primary heat transfer region(s) or area(s), though other regions such as regions between jet walls and well walls or within well channels may provide less, comparable, or even more total heat transfer. The relative contribution of each such region to heat transfer and to fluid pressure drop (or flow resistance) depends on surface area, fluid flow rate, temperature differential, flow turbulence, and the like. Modulation of variables such as, for example, number of jets, number of inlets, number of outlets, number of splitting chambers, size of splitting chambers, number of splitting levels, jet configuration, jet height, jet length, jet diameter, impact surface height, impact surface area, return channel width, return channel height, return channel length, locations of flow deflectors, variations in surface texture, surface and interior material properties, inclusion of stress relief structures, and the like, may be used to achieve a desired balance of fluid flow, fluid pressure differential, and heat flow or extraction capability. These parameters are not fixedly linked but can be independently adjusted using the design flexibility enabled by multi-layer electrochemical fabrication methods. To provide active temperature control from two temperature directions, some heat transfer arrays and/or some cold plates may incorporate heating elements (e.g. electrical heating elements) as well as cooling elements. In some embodiments, well-to-well flow paths or other flow paths may be provided to allow fluid flow from multiple jets to reach any specific area and/or to allow multi-path outflow of fluid from any given area to mitigate risk of array function failure due to blocked passages or a relatively small number of jets or other array elements (e.g. to maintain array functionality even in view of a 5%, 10%, 20% or even possibly 30% jet failure).
As noted previously, in some embodiments the bottom of each jet at one or more locations, e.g. at four locations, connect structurally to the surface onto which jetting occurs. This means that not only do the jets remove heat from the floor onto which jetting occurs via a flow of jetted fluid but also via heat conduction upward from the floor through the material of the jet wall. This means that the jet, in addition to functioning as a jet, also functions as a fin. Said another way, in these embodiments, these fin structures are hollow, and in addition to providing fin functionality, they also form jetting structures so as to provide overall improved heat removal and more effective use of volumetric space. These jets/fins also provide further heat removal, for example, via conducted heat by the portions of the jets/fins (portions below the top of the walls of the jetting wells) releasing conducted heat to the incoming jet stream via the interior surface of the jet structure and to the exiting jet stream via the external surface of the jetting/fin structure. In some embodiments, the upper surfaces of the jets may also remove further conducted heat via the flow of exhausted jetted fluid via the fluid flowing through a fluid exit path, channel, level or layer. Similarly the fins located between the jets that define the jetting wells also conduct heat away from the heat source via contact with exiting jetted fluid along their side walls and along their upper surfaces as well as along any supporting columns or jet side walls that extend upward therefrom. In some embodiments, like some of those shown, the fins (that also function as jets) are elongated to help with fluid flow by reducing flow resistance while at the same time providing more surface area for transferring heat from the side walls to the incoming and exiting fluid.
In some alternative embodiments, more than one inlet may be used, more than one outlet may be used, more than a single inlet level (e.g. in the Z-direction, e.g. direction parallel to an axis of layer stacking) and outlet level may be used.
In some embodiments, fluid flow through a whole thermal management system may involve transport of a trapped fluid from a primary heat pick up location, i.e. jetting impingement surface and primary heat transfer region, to an exit channel of a header or manifold, to a conventional heat exchanger (e.g. that removes heat by transferring to another fluid such as air or to a larger sink), to an optional filter (e.g. with a pore size of 10s of microns, to micron level or finer), to a pump, to an optional filter (e.g. micron level filter or finer), to an inlet of a header or manifold and back to the primary heat transfer location.
In some embodiments, a hybrid microjet and microchannel heat transfer array is provided to take advantage of the high convection performance of the microjet and the high surface area of a microchannel. In some embodiments, the microjet may include fin functionality. In some embodiments, cold plates are miniaturized by using a micro additive manufacturing process (such as those described herein) alone or in combination with traditional manufacturing to produce micro heat transfer arrays in high volume. In some embodiments, multilayer microchannels with microjets connecting the multiple layers creates 3-D flow behavior that generates high convection coefficients and heat transfer at all surfaces. In some embodiments, high strength materials like nickel cobalt (NiCo), or palladium, or anti-corrosion combinations of materials may be used to minimize corrosion and the generation of particles that can jam the fluid system and cause failure of pumps or jets. In some embodiments, volumes with high fluid velocities or turbulent flow may be reinforced (with hard materials such as rhodium) to minimize erosion of the surface over time. In some embodiments, composite material construction may be used to allow for optimizing strength, conductivity, and surface properties as needed.
Various embodiments of the invention may provide thermal management for various devices and the heat transfer arrays may be used to move heat generated by a variety of devices including for example: (1) an IC; (2) a microprocessor; (3) an SOC; (4) an RFIC, e.g. an RF transmitter or RF receiver; (5) an optical transmitter or receiver; (6) a power amplifier; (7) a GPU; (8) a CPU; (9) a DSP; (10) an ASIC; (11) an APU; (12) an LED; (13) a laser diode; (14) a power electronic device, e.g. a power inverter or a power converter; (15) a photonic devices, (16) a propulsion system; (17) a solar array, e.g. for a micro satellite; (18) a radiator, e.g. for a micro satellite; (19) an engine of a micro drone; (20) a spacecraft component such as an SSPA; (21) a traveling wave tube amplifier; (22) a package that holds one or more of the devices of (1)-(21), and (23) a stack or plurality of stacks of devices sandwiched between separated arrays or interleaved with multiple arrays.
Structural or sacrificial dielectric materials may be incorporated into various embodiments of the present invention in a variety of different ways. Such materials may form a third or higher material on selected layers or may form one of the first two materials deposited on some layers. Additional teachings concerning the formation of structures on dielectric substrates and/or the formation of structures that incorporate dielectric materials into the formation process and possibility into the final structures are set forth in a number of patent applications filed Dec. 31, 2003. The first of these filings is U.S. Patent Application No. 60/534,184, which is entitled “Electrochemical Fabrication Methods Incorporating Dielectric Materials and/or Using Dielectric Substrates”. The second of these filings is U.S. Patent Application No. 60/533,932, which is entitled “Electrochemical Fabrication Methods Using Dielectric Substrates”. The third of these filings is U.S. Patent Application No. 60/534,157, which is entitled “Electrochemical Fabrication Methods Incorporating Dielectric Materials”. The fourth of these filings is U.S. Patent Application No. 60/533,891, which is entitled “Methods for Electrochemically Fabricating Structures Incorporating Dielectric Sheets and/or Seed layers That Are Partially Removed Via Planarization”. A fifth such filing is U.S. Patent Application No. 60/533,895, which is entitled “Electrochemical Fabrication Method for Producing Multi-layer Three-Dimensional Structures on a Porous Dielectric”. Additional patent filings that provide teachings concerning incorporation of dielectrics into the an electrochemical fabrication process include U.S. patent application Ser. No. 11/139,262, filed May 26, 2005, now U.S. Pat. No. 7,501,328, by Lockard, et al., and which is entitled “Methods for Electrochemically Fabricating Structures Using Adhered Masks, Incorporating Dielectric Sheets, and/or Seed Layers that are Partially Removed Via Planarization”; and U.S. patent application Ser. No. 11/029,216, filed Jan. 3, 2005 by Cohen, et al., now abandoned, and which is entitled “Electrochemical Fabrication Methods Incorporating Dielectric Materials and/or Using Dielectric Substrates”. These patent filings are each hereby incorporated herein by reference as if set forth in full herein.
Some embodiments may employ diffusion bonding or the like to enhance adhesion between successive layers of material. Various teachings concerning the use of diffusion bonding in electrochemical fabrication processes are set forth in U.S. patent application Ser. No. 10/841,384 which was filed May 7, 2004 by Cohen et al., now abandoned, which is entitled “Method of Electrochemically Fabricating Multilayer Structures Having Improved Interlayer Adhesion” and which is hereby incorporated herein by reference as if set forth in full.
The patent applications and patents set forth below are hereby incorporated by reference herein as if set forth in full. The teachings in these incorporated applications can be combined with the teachings of the instant application in many ways: For example, enhanced methods of producing structures may be derived from some combinations of teachings, enhanced structures may be obtainable, enhanced apparatus may be derived, and the like.
Though various portions of this specification have been provided with headers, it is not intended that the headers be used to limit the application of teachings found in one portion of the specification from applying to other portions of the specification. For example, alternatives acknowledged in association with one embodiment or aspect, are intended to apply to all embodiments or aspects to the extent that the features of the different embodiments or aspects make such application functional and do not otherwise contradict or remove all benefits of the adopted embodiment or aspect. Various other embodiments of the present invention exist. Some of these embodiments may be based on a combination of the teachings set forth herein directly with various teachings incorporated herein by reference.
In view of the teachings herein, many further embodiments, alternatives in design and uses of the embodiments of the instant invention will be apparent to those of skill in the art. As such, it is not intended that the invention be limited to the particular illustrative embodiments, alternatives, and uses described above but instead that it be solely limited by the claims presented hereafter.
This application relates, as indicated, to the following applications with each being incorporated herein by reference: Which isDkt No.App. No.Continuity TypeApp. No.Which was FilednowFragmentThis applicationclaims benefit of63/162,8262021 Mar. 18pending397-AThis applicationis a CIP of17/174,2182021 Feb. 11pending349-E17/174,218is a CNT of16/840,3052020 Apr. 310,957,624349-D16/840,305is a CNT of16/373,5692019 Apr. 210,665,530349-C16/373,569is a CNT of15/951,4812018 Apr. 12lapsed349-B15/951,481is a CNT of15/283,0132016 Sep. 30 9,953,899349-A15/283,013claims benefit of62/355,5572016 Jun. 28expired339-E15/283,013claims benefit of62/321,8402016 Apr. 13expired339-D15/283,013claims benefit of62/316,4702016 Mar. 31expired339-C15/283,013claims benefit of62/274,0562015 Dec. 31expired339-B15/283,013claims benefit of62/235,5472015 Sep. 30expired339-A
| Number | Date | Country | |
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| 63162826 | Mar 2021 | US | |
| 62355557 | Jun 2016 | US | |
| 62321840 | Apr 2016 | US | |
| 62316470 | Mar 2016 | US | |
| 62274056 | Dec 2015 | US | |
| 62235547 | Sep 2015 | US |
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| Parent | 16840305 | Apr 2020 | US |
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| Parent | 16373569 | Apr 2019 | US |
| Child | 16840305 | US | |
| Parent | 15951481 | Apr 2018 | US |
| Child | 16373569 | US | |
| Parent | 15283013 | Sep 2016 | US |
| Child | 15951481 | US |
| Number | Date | Country | |
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| Parent | 17174218 | Feb 2021 | US |
| Child | 17699049 | US |
