The present disclosure relates to vapor chambers for heatsinks.
A traditional remote heatpipe heatsink may be used as a heatsink to cool a high-power density application specific integrated circuit (ASIC). The remote heatpipe heatsink faces challenges that can yield unpredictable thermal (cooling) performance due to multiple factors. A first factor that can limit the thermal performance is a distance from a condenser to a radiator and to heatpipes (or to a vapor chamber (VC)) of the remote heatpipe heatsink. A second factor that can limit thermal performance is the space available for the heatpipes. While employing more heatpipes adjacent to a cold plate translates to better thermal performance than employing less heatpipes, space limitations can make it difficult to increase the number of heatpipes near the cold plate. A third factor that can limit thermal performance relates to flow control of a working fluid in the heatpipe heatsink. For example, failure to control the gas-liquid two-phase flow inside a large-sized vapor chamber of the heatpipe heatsink adversely impacts long-distance heat transfer by the heatpipe heatsink.
In an embodiment, a vapor chamber for a heatsink comprises: a housing having an exterior surface with an area to be positioned adjacent to a heat source, an interior surface to enclose contiguous chambers including an evaporator chamber adjacent to the area, a condenser chamber spaced from the evaporator chamber, and a connector chamber connecting the evaporator chamber to the condenser chamber, and interior walls that partition the contiguous chambers into channels that have open near ends adjacent to the evaporator chamber, wherein the channels extend from the open near ends, through the connector chamber, and into the condenser chamber, to provide fluid communication between the evaporator chamber and the condenser chamber; a wick on the interior surface of the housing that contains the evaporator chamber, the condenser chamber, and the connector chamber, and on the interior walls of the channels; and a working fluid in the contiguous chambers to circulate between the evaporator chamber and the condenser chamber via the channels to transfer heat away from and cool the heat source.
In another embodiment, a vapor chamber heatsink comprises: a vapor chamber including: a housing to form an evaporator that contains an evaporator chamber, a condenser spaced-apart from the evaporator and that contains a condenser chamber, and a connector section that connects the evaporator to the condenser and contains a connector chamber, the housing including interior walls that partition the connector chamber and the condenser chamber into channels that have open near ends adjacent to the evaporator chamber, wherein the channels extend from the open near ends, through the connector chamber, and into the condenser chamber, to provide fluid communication between the evaporator chamber and the condenser chamber; a wick on an interior surface of the evaporator, the connector section, and the condenser, and on the interior walls of the channels; and a working fluid to circulate between the evaporator chamber and the condenser chamber via the channels; a cold plate fixed to the evaporator to apply heat from a heat source to the evaporator; and a heat fin stack fixed to the condenser.
Embodiments presented herein include (i) a vapor chamber (VC) structure (also referred to simply a “VC”), and (ii) a remote directional VC heatsink that incorporates the VC structure to cool a heat source. The VC structure and the remote directional VC heatsink that incorporates the VC structure are described generally in connection with
Housing 102 includes a planar top area plate 108 formed in the T-shape and a planar bottom area plate 110 (hidden from view in
Housing 102 comprises a series of integrally formed contiguous housing sections including an evaporator 120, a condenser 122 spaced-apart (and thus “remote”) from the evaporator along a length of housing 102, and a phase-change connector section (referred to simply as a “connector”) 124 connecting the evaporator to the condenser. Evaporator 120 and connector 124 are connected in series to form a leg of the T-shape formed by housing 102, while condenser 122 forms a crossbar of the T-shape that is joined to the leg of the T-shape at a midpoint of the crossbar/condenser. Evaporator 120, connector 124, and condenser 122 enclose/contain a series of contiguous chambers, respectively, including an evaporator chamber 120c, a connector chamber 124c connecting the evaporator chamber to the condenser chamber, and a condenser chamber 122c that are in fluid communication with each other, and that collectively form large chamber 116. The working fluid may flow within and between chambers 120c-124c. Evaporator chamber 120c, connector chamber 124c, and condenser chamber 122c have respective volumes V1, V2, and V3 defined by their length (L), width (W), and height (H)) dimensions shown in
At a high-level, VC heatsink 200 is configured to cool the heat source (e.g., the ASIC) in contact with the cold plate of metal block structure 204 due to interactions between VC structure 100 including the working fluid, the metal block structure, and heat fin stack 206. For example, heat from the heat source spreads radially across evaporator 120 and vaporizes any working fluid present in evaporator chamber 120c to a vapor (e.g., steam). Interior channels (described below) formed within housing 102 direct the vapor from evaporator chamber 120c through connector chamber 124c into condenser chamber 122c, where the vapor condenses to a liquid. The liquid flows from condenser chamber 122c back to evaporator chamber 120c through connector chamber 124c, and the cycle repeats to cool the heat source, as will be described in further detail below.
VC structure 100 is now described in further detail with reference to
As best shown in
Each of interior walls IW1-IW7 has a respective vertical side of height H1 (see
In connector chamber 124c, interior sidewalls IW1-IW7 are equally spaced-apart from each other across width W1 and extend in parallel with each other along their lengths (in parallel with length L2, shown in
In condenser chamber 122c, interior sidewalls IW1-IW3 turn or branch leftward (e.g., in a first direction), away from the center axis/center interior wall IW4, in a stepped fashion to retain their parallel spaced relationship in the condenser chamber. The turn may be a hard right-angle (i.e., 90°) turn to the left as shown, or may be a curved right-angle turn to the left along a bend. In another example, the turn may be less than a right-angle turn, e.g., an 80° turn. From there, interior sidewalls IW1-IW3 extend leftward (e.g., in the first direction) in parallel with each other (and in parallel with width W2 of condenser chamber 122c) toward a left edge E5 of condenser 122. In the example of
In condenser chamber 122c, opposite to interior sidewalls IW1-IW3, interior sidewalls IW5-IW7 turn or branch to the right (e.g., in a second direction generally opposite to the first direction), away from the center axis/center interior wall IW4, in a stepped fashion to retain their parallel spaced relationship. The turn may be a hard right-angle turn to the right as shown, or may be a curved right-angle turn to the left along a bend. In another example, the turn may be less than a right-angle turn, e.g., an 80° turn. From there, interior sidewalls IW5-IW7 extend rightward (e.g., in the second direction) in parallel with each other toward a right edge E7 of condenser 122. In the example of
With reference to
As mentioned above, VC heatsink 200 is configured to cool the heat source (e.g., the ASIC) in contact with the cold plate of metal block structure 204 due to interactions between VC structure 100 including its working fluid, the metal block structure, and heat fin stack 206. More specifically, evaporator 120 receives/absorbs heat generated by the heat source fixed to the cold plate and efficiently spreads the heat in two (planar) dimensions (e.g., radially, as shown in
Because condenser 122 is remote from the heat source, the condenser is cooler (i.e., lower in temperature than) evaporator 120. The lower temperature condenses the vapor in condenser chamber 122c to a liquid. The liquid adheres to the wick coating the interior surfaces of condenser 122 and the sides of channels C1-C8. Open left far ends 306L and open right far ends 306R of channels C1-C4 and C5-C7, respectively, encourage mixing between and movement of the vapor and liquid in condenser chamber 122c near the edges of condenser 122. Due to capillary pressure, the liquid flows directionally in/along wick 602 from condenser chamber 122c back to evaporator chamber 120c, through/along channels C1-C8. The directional flow of liquid is shown by dashed arrows in
An advantage of the configuration of channels C1-C8 is that they constrain the flow of vapor and liquid in opposite directions of one dimension (along the length of connector 124 and the width of condenser 122, but not in the vertical/height direction), which increases transportation speed and efficiency. That is, channels C1-C8 force gas-liquid flow in a directional order to enhance thermal performance. Moreover, circulation of the working fluid does not depend on gravity.
With reference to
Operation 802 includes providing a housing having (i) an exterior surface with an area to be positioned adjacent to the heat source, (ii) an interior surface to enclose contiguous chambers including an evaporator chamber adjacent to the area, a condenser chamber spaced from the evaporator chamber, and a connector chamber connecting the evaporator chamber to the condenser chamber, and (iii) interior walls that partition the contiguous chambers into channels that have open near ends adjacent to the evaporator chamber. The channels extend from their open near ends, through the connector chamber, and into the condenser chamber, to provide fluid communication between the evaporator chamber and the condenser chamber.
Operation 804 includes providing a wick that coats the interior surface of the housing that contains the evaporator chamber, the condenser chamber, and the connector chamber, and coats the interior walls that form the channels.
Operation 806 includes providing a working fluid in the contiguous chambers.
Operation 808 includes, by the evaporator chamber, receiving heat from the heat source, which causes the working fluid in the evaporator chamber to vaporize from a liquid to a vapor.
Operation 810 includes, by the channels, directing the vapor from the evaporator chamber to the condenser chamber.
Operation 812 includes (i) by the channels, spreading the vapor in the condenser chamber in opposite directions to edges of the condenser chamber, and (ii) by the condenser chamber, condensing the vapor to the liquid.
Operation 814 includes, by the wick, transporting the liquid from the condenser chamber, along the interior walls forming the channels, to the evaporator chamber.
The VC heatsink provides a higher cooling and thermal performance compared to conventional heatpipe heatsinks. The VC heatsink also avoids drying-out of the wick at the evaporator. The VC heatsink reduces metal (e.g., copper) usage, and weight compared to the conventional heatpipe heatsinks.
In some aspects, the techniques described herein relate to an apparatus in the form of a vapor chamber for a heatsink including: a housing having (i) an exterior surface with an area to be adjacent to a heat source, (ii) an interior surface to enclose contiguous chambers including an evaporator chamber adjacent to the area, a condenser chamber spaced from the evaporator chamber, and a connector chamber connecting the evaporator chamber to the condenser chamber, and (iii) interior walls that partition the contiguous chambers into channels that have open near ends adjacent to the evaporator chamber, wherein the channels extend from the open near ends, through the connector chamber, and into the condenser chamber, to provide fluid communication between the evaporator chamber and the condenser chamber; a wick on the interior surface of the housing that contains the evaporator chamber, the condenser chamber, the connector chamber, and on the interior walls of the channels; and a working fluid in the contiguous chambers to circulate between the evaporator chamber and the condenser chamber via the channels to transfer heat away from and cool the heat source.
In some aspects, the techniques described herein relate to a vapor chamber, wherein: the housing has a length and a width that is transverse to the length; the evaporator chamber is spaced from the condenser chamber along the length; and the channels include first channels and second channels that extend through the connector chamber in parallel with each other on a first side and a second side of the width, respectively, and branch away from each other in the condenser chamber.
In some aspects, the techniques described herein relate to a vapor chamber, wherein the open near ends of the channels terminate at an edge of the evaporator chamber so as not to enter the evaporator chamber, and the channels terminate at open far ends of the channels within the condenser chamber.
In some aspects, the techniques described herein relate to a vapor chamber, wherein the open near ends of the channels terminate at an edge of the evaporator chamber so as not to enter the evaporator chamber, and the channels terminate at closed far ends of the channels that are joined to the housing in the condenser chamber.
In some aspects, the techniques described herein relate to a vapor chamber, wherein the housing includes: top and bottom area plates, spaced-apart from each other by a height that is transverse to a length and a width of the housing, the top and bottom area plates having respective edges that are joined together to form contiguous housing sections that enclose the contiguous chambers.
In some aspects, the techniques described herein relate to a vapor chamber, wherein the contiguous housing sections form an evaporator, a condenser spaced-apart from the evaporator along the length, and a connector section connecting the evaporator to the condenser that respectively contain the evaporator chamber, the condenser chamber, and the connector chamber.
In some aspects, the techniques described herein relate to a vapor chamber, wherein an outer surface of the evaporator includes the area to be adjacent to the heat source.
In some aspects, the techniques described herein relate to a vapor chamber, wherein, to cool the heat source: the evaporator is configured to spread the heat from the heat source across the evaporator to cause the working fluid to vaporize from a liquid to a vapor; the channels are configured to direct the vapor from the evaporator to the condenser; the condenser is configured to condense the vapor to the liquid; and the wick is configured to transport the liquid from the condenser, along the interior walls forming the channels, to the evaporator.
In some aspects, the techniques described herein relate to a vapor chamber, wherein the housing has a T-shape such that the evaporator and the connector section are connected in series to form a leg of the T-shape and the condenser forms a crossbar of the T-shape that is joined to the leg of the T-shape.
In some aspects, the techniques described herein relate to a vapor chamber, wherein the interior walls are configured to form first channels and second channels of the channels that extend through the connector section in parallel with each other on a first side and a second side of the width, respectively, and extend away from each other in the condenser.
In some aspects, the techniques described herein relate to a vapor chamber, wherein the interior walls (i) have top and bottom edges joined to the top and bottom area plates along lengths of the interior walls, and (ii) are spaced-apart from each other across the width so as to be parallel with each other along the lengths of the interior walls.
In some aspects, the techniques described herein relate to a vapor chamber, wherein the housing includes copper, and the wick includes sintered copper.
In some aspects, the techniques described herein relate to an apparatus in the form of a vapor chamber heatsink including: a vapor chamber including: a housing to form an evaporator that contains an evaporator chamber, a condenser spaced-apart from the evaporator and that contains a condenser chamber, and a connector section that connects the evaporator to the condenser and contains a connector chamber, the housing including interior walls that partition the connector chamber and the condenser chamber into channels that have open near ends adjacent to the evaporator chamber, wherein the channels extend from the open near ends, through the connector chamber, and into the condenser chamber, to provide fluid communication between the evaporator chamber and the condenser chamber; a wick on an interior surface of the evaporator, the connector section, and the condenser, and on the interior walls of the channels; and a working fluid to circulate between the evaporator chamber and the condenser chamber via the channels; a cold plate fixed to the evaporator to apply heat from a heat source to the evaporator; and a heat fin stack fixed to the condenser.
In some aspects, the techniques described herein relate to a vapor chamber heatsink, wherein: the channels extend in parallel through the connector chamber along a length of the connector chamber, and the channels extend in parallel along a width of the condenser chamber that is transverse to the length.
In some aspects, the techniques described herein relate to a vapor chamber heatsink, wherein: the channels include first channels and second channels that (i) extend through the connector chamber in parallel on a first side and a second side of the width, respectively, and (ii) branch away from each other in the condenser chamber.
In some aspects, the techniques described herein relate to a vapor chamber heatsink, wherein the housing has a T-shape such that the evaporator and the connector section are connected in series to form a leg of the T-shape and the condenser forms a crossbar of the T-shape that is joined to the leg of the T-shape.
In some aspects, the techniques described herein relate to a vapor chamber heatsink, wherein, to cool the heat source: the evaporator is configured to spread the heat across the evaporator to cause the working fluid to vaporize from a liquid to a vapor; the channels are configured to direct the vapor from the evaporator to and across the condenser; the condenser is configured to condense the vapor to the liquid; and the wick is configured to transport the liquid from the condenser, along the channels, to the evaporator.
In some aspects, the techniques described herein relate to a method including: providing a housing having (i) an exterior surface with an area to be positioned adjacent to a heat source, (ii) an interior surface to enclose contiguous chambers including an evaporator chamber adjacent to the area, a condenser chamber spaced from the evaporator chamber, and a connector chamber connecting the evaporator chamber to the condenser chamber, and (iii) interior walls that partition the contiguous chambers into channels that have open near ends adjacent to the evaporator chamber, wherein the channels extend from the open near ends, through the connector chamber, and into the condenser chamber, to provide fluid communication between the evaporator chamber and the condenser chamber; providing a wick on the interior surface of the housing that contains the evaporator chamber, the condenser chamber, the connector chamber, and on the interior walls of the channels; providing a working fluid in the contiguous chambers; by the evaporator chamber, receiving heat from the heat source, which causes the working fluid to vaporize from a liquid to a vapor; by the channels, directing the vapor from the evaporator chamber to the condenser chamber; by the condenser chamber, condensing the vapor to the liquid; and by the wick, transporting the liquid from the condenser chamber, along the interior walls forming the channels, to the evaporator chamber.
In some aspects, the techniques described herein relate to a method, wherein the interior walls form first channels and second channels of the channels that extend through the connector chamber in parallel with each other on a first side and a second side of a width of the connector chamber, respectively, and extend away from each other in the condenser chamber.
In some aspects, the techniques described herein relate to a method, wherein the open near ends of the channels terminate at an edge of the evaporator chamber so as not to enter the evaporator chamber, and the channels terminate at open far ends of the channels in the condenser chamber.
Note that in this Specification, references to various features (e.g., elements, structures, nodes, modules, components, engines, logic, steps, operations, functions, characteristics, etc.) included in ‘one embodiment’, ‘example embodiment’, ‘an embodiment’, ‘another embodiment’, ‘certain embodiments’, ‘some embodiments’, ‘various embodiments’, ‘other embodiments’, ‘alternative embodiment’, and the like are intended to mean that any such features are included in one or more embodiments of the present disclosure, but may or may not necessarily be combined in the same embodiments.
It is also noted that the operations and steps described with reference to the preceding figures illustrate only some of the possible scenarios that may be executed by one or more components/entities discussed herein. Some of these operations may be deleted or removed where appropriate, or these steps may be modified or changed considerably without departing from the scope of the presented concepts. In addition, the timing and sequence of these operations may be altered considerably and still achieve the results taught in this disclosure. The preceding operational flows have been offered for purposes of example and discussion. Substantial flexibility is provided by the embodiments in that any suitable arrangements, chronologies, configurations, and timing mechanisms may be provided without departing from the teachings of the discussed concepts.
As used herein, terms such as first and second, left and right, and upper and lower, are relative and may be used in place of each other. For example, first and left (or right) may be used interchangeably, second and right (or left) may be used interchangeably, first and upper (or lower) may be used interchangeably, and second and lower (or upper) may be used interchangeably. As used herein, unless expressly stated to the contrary, use of the phrase ‘at least one of’, ‘one or more of’, ‘and/or’, variations thereof, or the like are open-ended expressions that are both conjunctive and disjunctive in operation for any and all possible combination of the associated listed items. For example, each of the expressions ‘at least one of X, Y and Z’, ‘at least one of X, Y or Z’, ‘one or more of X, Y and Z’, ‘one or more of X, Y or Z’ and ‘X, Y and/or Z’ can mean any of the following: 1) X, but not Y and not Z; 2) Y, but not X and not Z; 3) Z, but not X and not Y; 4) X and Y, but not Z; 5) X and Z, but not Y; 6) Y and Z, but not X; or 7) X, Y, and Z.
Each example embodiment disclosed herein has been included to present one or more different features. However, all disclosed example embodiments are designed to work together as part of a single larger system or method. This disclosure explicitly envisions compound embodiments that combine multiple previously discussed features in different example embodiments into a single system or method.
Additionally, unless expressly stated to the contrary, the terms ‘first’, ‘second’, ‘third’, etc., are intended to distinguish the particular nouns they modify (e.g., element, condition, node, module, activity, operation, etc.). Unless expressly stated to the contrary, the use of these terms is not intended to indicate any type of order, rank, importance, temporal sequence, or hierarchy of the modified noun. For example, ‘first X’ and ‘second X’ are intended to designate two ‘X’ elements that are not necessarily limited by any order, rank, importance, temporal sequence, or hierarchy of the two elements. Further as referred to herein, ‘at least one of’ and ‘one or more of’ can be represented using the ‘(s)’ nomenclature (e.g., one or more element(s)).
One or more advantages described herein are not meant to suggest that any one of the embodiments described herein necessarily provides all of the described advantages or that all the embodiments of the present disclosure necessarily provide any one of the described advantages. Numerous other changes, substitutions, variations, alterations, and/or modifications may be ascertained to one skilled in the art and it is intended that the present disclosure encompass all such changes, substitutions, variations, alterations, and/or modifications as falling within the scope of the appended claims.