Contact cooling device

Abstract

A high performance cooling device including multiple, relatively thin plates, each having patterns formed thereon that, as arranged within the device, cause turbulence in a fluid passing within the cold plate. Adjacent ones of the plates within the cold plate are arranged such that fluid passing channels within their patterns are arranged crosswise. The plates may be arranged such that the fluid passing channels within the adjacent plate patterns are at an included angle of between 36 and 60 degrees. Manufacturing of the device includes stacking the plates in an alternating fashion such that the channels within the pattern of each plate are crosswise with respect to the channels in the pattern of an adjacent plate. A pair of end plates, which are stacked at the top and bottom of the assembly, do not have an etched pattern and allow for fluid input and output ports. During operation of the disclosed device, the ports bring fluid, such as a coolant, into and out of the device.

Description

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] N/A

BACKGROUND OF THE INVENTION

[0003] The present invention relates generally to a cooling apparatus and more specifically to a design for a contact cooling device operable to introduce turbulence into a cooling fluid for improved cooling characteristics.

[0004] As it is generally known, overheating of various types of electronic components may result in their failure or destruction. The need for effective heat removal techniques in this area is accordingly a basic problem. Various types of systems have been designed to cool electronic components in order to increase the MTBF (Mean Time Between Failure) of those components. In some existing systems, fluid has been passed through cold plates or heat sinks in order to transfer heat away from devices or components to be cooled. While such existing systems have sometimes been effective in certain applications, there is an ongoing need to provide improved thermal transfer characteristics in such devices.

[0005] Accordingly, it would be desirable to have a cooling device that provides improvements in thermal transfer characteristics over previous systems that have used fluid flows to facilitate cooling of attached or proximate electronic devices.

BRIEF SUMMARY OF THE INVENTION

[0006] A high performance cooling device is disclosed, wherein the cooling device includes multiple, relatively thin plates, each having patterns formed thereon causing turbulence in a fluid passing within the cold plate. Adjacent ones of the plates within the device have their patterns shifted so that flow channels within the adjacent patterns criss-cross each other, for example intersecting at some included angle within the range of 36 to 60 degrees. The plates therefore may be arranged such that adjacent plate patterns are effectively mirror images of each other.

[0007] In an illustrative embodiment, the plates within the cooling device are fabricated using relatively thin (0.040″-0.100″) copper plates that have been photo-etched, stamped, forged, cast, or which have been processed or produced in some other fashion to produce an advantageous pattern. Channels within the pattern formed on the copper plates induce turbulent flow to a fluid passing within the cooling device to increase the overall thermal transfer performance of the device. In one embodiment, a two pass design is used, in which inlet and outlet fluid ports are located on one end of the device. Alternatively, the disclosed device could be embodied in a one pass design, in which the inlet and outlet ports are located on opposite ends of the device.

[0008] In a preferred method of manufacturing the disclosed device, the plates are assembled by first plating the individual plates with an 85/15 tin lead solder or other suitable metal or alloy, to a thickness of 0.0005-0.003 inches. The individual plates are then stacked in an alternating fashion such that the channels of the patterns of adjacent plates are mirror images, for example crisscrossing at an included angle within the range of 36 to 60 degrees, or at some other suitable angle. A pair of end plates may be stacked at the top and bottom of the assembly, which may not have an etched pattern, or which may feature some other etched pattern than that of the interior plates, and which allow for fluid input and output ports. During operation of the disclosed device, the ports bring fluid in and out of the device. The fluid passing channels of the pattern may extend partly or completely across the width of the patterned plates.

[0009] Further during the disclosed process for making the disclosed device, the stacked plates are placed in a fixture and soldered in a vacuum or inert atmosphere. A mechanical load is applied to maintain contact pressure between the plates during this process. The fixture used for soldering the plates together can also be designed to provide for soldering various sized pads or blocks on the surface interfacing the components requiring cooling. In this way, a “custom topography” may be introduced to the surface interfacing with the components requiring cooling. Such an approach potentially eliminates an expensive machining operation.

[0010] Thus there is disclosed a new cooling device that provides improvements in thermal transfer characteristics over previous systems using fluid flows to facilitate cooling of attached or proximate electronic devices.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0011] The invention will be more fully understood by reference to the following detailed description of the invention in conjunction with the drawings, of which:

[0012] FIG. 1 shows the geometry of flow channels in a device including multiple plates adapted to include a pattern consistent with the disclosed system on one side;

[0013] FIG. 2 shows the structure of the disclosed device in an alternative embodiment; and

[0014] FIG. 3 shows a cross section of a soldering fixture which may be used to form a block of plates in accordance with an illustrative embodiment of the disclosed system.

DETAILED DESCRIPTION OF THE INVENTION

[0015] All disclosures of provisional patent application serial No. 60/371,883, entitled “CONTACT COOLING DEVICE”, filed Apr. 11, 2002, are hereby incorporated herein by reference.

[0016] A high performance cooling device is disclosed, which may, for example, be fabricated using an assembly of relatively thin (0.040″-0.100″) copper plates that each include a pattern having a number of fluid flow channels. The pattern may be formed on the patterned plates using any appropriate technique, for example by photo-etching, stamping, forging, casting or other processes.

[0017] FIG. 1 shows an example embodiment 10 of the disclosed cooling device. As shown in FIG. 1, a first set of channels 12 are defined by a first plate within the device 10, while a second set of channels 14 are defined by a second plate within the device 10. In the illustrative embodiment of FIG. 1, the flow channels 12 and 14 have been formed in corresponding copper plates to form the patterned plates stacked within the resulting device 10.

[0018] FIG. 1 further shows a fluid inlet port 18 allowing fluid to pass into the device, an input coolant distribution plenum 16 for passing fluid to the channels 12, and an output coolant distribution plenum 17 for collecting fluid from the channels 12 and passing the fluid to a fluid outlet port 19. While, for purposes of illustration, FIG. 1 shows inlet and outlet ports only with regard to the plate including the channels 12, the plate including the channels 14 may also include its own inlet and outlet ports.

[0019] The illustrative embodiment shown in FIG. 1 illustrates how the fluid flow channels 12 and 14 of adjacent plates are arranged cross wise to each other when the plates are joined together. Such an arrangement introduces turbulence into a liquid that is flowed through the device, thereby improving the thermal performance of the device 10.

[0020] The illustrative embodiment of FIG. 1 may be implemented as a two pass design, where a fluid inlet port and a fluid outlet port are located on the same end of the device 10. Alternatively, a single pass design may be used, in which inlet and outlet ports are configured on opposite ends of the device 10.

[0021] For purposes of explanation, the fluid flow channels 12 and 14 may have a depth of between 0.027 to 0.060 inches and a width of between 0.045 and 0.080 inches. The angle of the channels 12 may, for example, be between 18 and 30 degrees with respect to a lengthwise side of the device 10, while the angle of the channels 14 may be between negative 18 and negative 30 degrees with respect to that side of the device. The specific angles of and numbers of channels shown in the illustrative embodiments of FIGS. 1-3 are for purposes of illustration only, and the present invention may be embodied with numbers of channels and channel angles other than those shown.

[0022] FIG. 2 illustrates the assembly of an alternative embodiment of the disclosed system. As shown in FIG. 2, a first end plate 20 includes a fluid inlet port 22 and a fluid outlet port 24. A first plate 26 includes a patterned portion 28 defined by at least a first set of angled bars arranged crosswise defining a first set of fluid flow channels on a first side of the plate 26. The patterned portion 28 of the plate 26 may itself further include a second set of angled bars defining a second set of fluid flow channels arranged crosswise with respect to the first set of fluid flow channels on an opposite side of said plate 26. The angled bars of the patterned portion 28 are, for example, substantially rectangular, and extend in an angular fashion between the lengthwise sides of the plate 26. In the case where the patterned portion 28 defines two sets of fluid flow channels arranged crosswise to each other, then the plate 29 includes a similar patterned section 31 defining two sets of channels arranged crosswise with respect to each other. Alternatively, the plate 26 may only define one set of fluid flow channels extending angularly between its lengthwise sides, in which case the plate 29 would include a single set of fluid flow channels arranged crosswise with respect to the fluid flow channels of plate 26.

[0023] The angle of the flow channels may be any appropriate predetermined angle. For example, the angle of the flow channels in a first plate with respect to a given side of the device may be within a range of 18 to 30 degrees, and within a range of between −18 to −30 degrees in the adjacent plate with respect to the same side of the device. In this way, the channels of adjacent plates run criss-cross, or crosswise, at an angle to each other. The included angle with respect to the intersection of channels in adjacent plates may, accordingly, be within the range of 36 to 60 degrees.

[0024] Further as shown in FIG. 2, a second end plate 33 is used, having a patterned portion 35 etched therein defining some number of fluid flow channels. The first end plate 20, plates 26 and 29, and second end plate 33 are joined together through any appropriate means to form the alternative embodiment of the disclosed cooling device shown in FIG. 2.

[0025] In a method of manufacturing the disclosed cooling device, the disclosed device is assembled by first plating the individual patterned plates with an 85/15 tin lead solder or other suitable metal or alloy, to a thickness of 0.0005-0.003 inches. The individual patterned plates are then stacked in an alternating fashion such that the fluid flow channels of the pattern of each adjacent plate is crosswise with respect to its neighboring plate or plates. For example, each plate may be arranged in the stack so that its fluid flow channels are at a predetermined angle with respect to the fluid flow channels of its neighboring plates. The last plates put into the stack, which are stacked at the top and bottom of the assembly, are end plates which may or may not have an etched pattern, and which allow for input and output fluid ports. During operation of the disclosed device, the ports bring fluid into and out of the device.

[0026] Further during the disclosed manufacturing process, as shown in FIG. 2, the stacked patterned plates 30 and end plates 32 are placed in a fixture 34, and soldered in a vacuum or inert atmosphere. A mechanical load is applied to maintain contact pressure between the plates 30 and 32 during this process. The fixture 34 used for soldering the plates 30 and 32 together can also be designed or configured to provide for soldering various size pads or blocks to allow a method of offering “custom topography” to the surface interfacing with the components requiring cooling. This feature would eliminate an expensive machining operation. FIG. 2 shows a cross section of soldering fixture which has pockets 36 machined in place to precisely position the blocks 38 during soldering.

[0027] While the invention is described through the above exemplary embodiments, it will be understood by those of ordinary skill in the art that modification to and variation of the illustrated embodiments may be made without departing from the inventive concepts herein disclosed. Accordingly, the invention should not be viewed as limited except by the scope and spirit of the appended claims.

Claims

1. A cooling device, comprising: a plurality of patterned plates, each of said patterned plates having a pattern formed thereon, wherein said pattern includes a plurality of channels through which liquid can pass, and wherein said plates are arranged such that said channels of said pattern in a first one of said patterned plates are arranged substantially crosswise with respect to said channels of said pattern in a second, adjacent one of said plurality of patterned plates.

2. The cooling device of claim 1, wherein said plates are arranged such that each of said channels of said pattern in said first one of said patterned plates are arranged at an included angle of between 36 and 60 degrees with respect to said channels of said second, adjacent plate.

3. The cooling device of claim 2, further comprising a pair of end plates coupled to opposite sides of the device, wherein said end plates include an input port for allowing a fluid to enter said device and an output port for allowing a fluid to exit said device.

4. The cooling device of claim 3, wherein said plurality of patterned plates are formed primarily of copper.

5. The cooling device of claim 1, wherein said patterned plates are rectangular, and wherein said channels in said pattern extend angularly from a lengthwise side of said first one of said patterned plates, wherein said lengthwise side of said first one of said patterned plates corresponds to a lengthwise side of said device.

6. The cooling device of claim 5, wherein said channels in said pattern extend at an angle within the range of 18 to 30 degrees from said lengthwise side in said first one of said patterned plates.

7. The cooling device of claim 8, wherein said channels in said pattern extend at an angle within the range of negative 18 to negative 30 degrees from said lengthwise side in said second, adjacent one of said patterned plates.

8. A method of manufacturing a cooling device, comprising: forming a pattern on a plurality of plates to produce a plurality of patterned plates, wherein said pattern includes a plurality of channels through which liquid can pass; arranging said plurality of patterned plates in a stack such that said channels of said pattern in a first one of said patterned plates are crosswise with respect to channels in said pattern of a second, adjacent one of said plurality of patterned plates in said stack; and affixing a pair of end plates to said stack, wherein said pair of end plates include an input fluid port and an output fluid port.

9. The method if claim 8, wherein said forming said pattern on said plurality of plates to produce said plurality of patterned plates includes photo-etching said pattern onto said plurality of plates.

10. The method of claim 8, wherein said forming said pattern on said plurality of plates to produce said plurality of patterned plates includes stamping said pattern onto said plurality of plates.

11. The method of claim 8, wherein said forming said pattern on said plurality of plates to produce said plurality of patterned plates includes casting said plurality of plates to obtain said pattern.

12. The method of claim 8, wherein said forming said pattern on said plurality of plates to produce said plurality of patterned plates include forging said plurality of plates to obtain said pattern.

13. The method of claim 8, further comprising attaching a pair of end plates to said stack, wherein said end plates include an input port for allowing liquid into said cooling device, and an output port for allowing liquid out of said cooling device.

14. The method of claim 8, further comprising placing said stack into a fixture and soldering said patterned plates together while a mechanical load is applied to maintain contact pressure between the patterned plates in the stack.

15. The method of claim 14, further comprising soldering at least one pad on a component contact surface of said cooling device while soldering said patterned plates together.