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Publication numberUS20020195231 A1
Publication typeApplication
Application numberUS 10/219,255
Publication dateDec 26, 2002
Filing dateAug 16, 2002
Priority dateApr 9, 2001
Publication number10219255, 219255, US 2002/0195231 A1, US 2002/195231 A1, US 20020195231 A1, US 20020195231A1, US 2002195231 A1, US 2002195231A1, US-A1-20020195231, US-A1-2002195231, US2002/0195231A1, US2002/195231A1, US20020195231 A1, US20020195231A1, US2002195231 A1, US2002195231A1
InventorsWing Siu
Original AssigneeSiu Wing Ming
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Laminated heat transfer device and method of producing thereof
US 20020195231 A1
Abstract
A laminated heat transfer device for cooling or thermal energy transport applications and a method of manufacture thereof. In various implementations, the laminated heat transfer device provides complex duct channels for efficient cooling. The various implementations are compatible and integrateable with each other.
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Claims(58)
What is claimed is:
1. A laminated heat transfer device, comprising
a base; and
a vane formed from a plurality of laminae, each lamina having a plurality of fins and a conduction core,
wherein the laminae are stacked according to a predetermined sequence.
2. The laminated heat transfer device of claim 1, further comprising:
at least one guide rod to guide the stacking of laminae.
3. The laminated heat transfer device of claim 1, further comprising:
an alignment fixture to guide the stacking of laminae.
4. The laminated heat transfer device of claim 3, wherein the stacking of laminae comprises folding a lamina upon itself.
5. The laminated heat transfer device of claim 3, wherein the stacking of laminae comprises piling a lamina upon itself.
6. The laminated heat transfer device of claim 3, wherein the stacking of laminae comprises a combination of folding and piling a lamina.
7. The laminated heat transfer device of claim 1, wherein the laminae are of equal size or varying size.
8. The laminated heat transfer device of claim 1, wherein the laminae are shaped like spokes of a wheel.
9. The laminated heat transfer device of claim 1, wherein at least one of the laminae is shaped like a web.
10. The laminated heat transfer device of claim 1, wherein the fins of the heat sink form a spiral.
11. The laminated heat transfer device of claim 1, wherein the heat sink is a ducting-type heat sink.
12. A laminated heat transfer device, comprising
a base; and
a porous structure formed from a plurality of first and second laminae, each lamina having a plurality of shaped openings,
wherein the laminae are stacked according to a predetermined sequence.
13. The laminated heat transfer device of claim 12, wherein the stacking of laminae comprises folding a lamina upon itself.
14. The laminated heat transfer device of claim 12, wherein the stacking of laminae comprises piling a lamina upon itself.
15. The laminated heat transfer device of claim 12, wherein the stacking of laminae comprises a combination of folding and piling a lamina.
16. The laminated heat transfer device of claim 12, wherein the first and second laminae are alternately stacked and wherein the laminae are stacked horizontally or vertically.
17. The laminated heat transfer device of claim 12, wherein the shaped openings of each lamina are uniformly spaced.
18. The laminated heat transfer device of claim 12, wherein the shaped openings of each lamina are non-uniformly spaced.
19. The laminated heat transfer device of claim 12, wherein the shaped openings of each lamina are non-uniformly sized.
20. The laminated heat transfer device of claim 12, wherein the shaped openings of each lamina comprise the shapes of a rectangle, an oval, or a circle.
21. The laminated heat transfer device of claim 12, wherein the laminae are of equal size or varying size.
22. The laminated heat transfer device of claim 12, wherein the laminated heat transfer device is a heat sink.
23. The laminated heat transfer device of claim 22, wherein the heat sink is a porous-type heat sink.
24. The laminated heat transfer device of claim 12, further comprising:
two end plates, and
wherein the openings of the primary and secondary laminae are different sizes in order to form grooves when the laminae are stacked together.
25. The laminated heat transfer device of claim 24, wherein the primary and secondary laminae are cut to form channels across the laminae toward the end plates when the laminae are stacked together.
26. The laminated heat transfer device of claim 24, further comprising:
two plates, each plate being formed with a plurality of slits and positioned before the respective end plate.
27. The laminated heat transfer device of claim 24, wherein the laminated heat transfer device is a heat pipe.
28. The laminated heat transfer device of claim 12, further comprising:
two end plates, and
wherein the openings of the primary and secondary laminae are the same size in order to form grooves when the laminae are stacked together.
29. The laminated heat transfer device of claim 28, wherein the primary and secondary laminae are cut to form channels across the laminae toward the end plates when the laminae are stacked together.
30. The laminated heat transfer device of claim 26, further comprising:
two plates, each plate being formed with a plurality of slits and positioned before the respective end plate.
31. The laminated heat transfer device of claim 27, wherein the laminated heat transfer device is a heat pipe.
32. A laminated heat transfer device, comprising
a base; and
a plurality of laminae formed with thermo-electric junctions, the laminae being stacked according to a predetermined sequence wherein a first group of laminae are attached to the base and a second group of laminae are thermally isolated.
33. The laminated heat transfer device of claim 32, wherein the stacking of laminae comprises folding a lamina upon itself.
34. The laminated heat transfer device of claim 32, wherein the stacking of laminae comprises piling a lamina upon itself.
35. The laminated heat transfer device of claim 32, wherein the stacking of laminae comprises a combination of folding and piling a lamina.
36. The laminated heat transfer device of claim 32, wherein the laminated heat transfer device is a split-body Peltier device.
37. A laminated heat transfer device, comprising the laminated heat transfer device as claimed in claim 1 formed integrally with the laminated heat transfer device as claimed in claim 24.
38. A laminated heat transfer device, comprising the laminated heat transfer device as claimed in claim 12 formed integrally with the laminated heat transfer device as claimed in claim 24.
39. A laminated heat transfer device, comprising the laminated heat transfer device as claimed in claim 24 formed integrally with the laminated heat transfer device as claimed in claim 32.
40. A laminated heat transfer device, comprising the laminated heat transfer device as claimed in claim 1 formed integrally with the laminated heat transfer device as claimed in claim 25.
41. A laminated heat transfer device, comprising the laminated heat transfer device as claimed in claim 12 formed integrally with the laminated heat transfer device as claimed in claim 25.
42. A laminated heat transfer device, comprising the laminated heat transfer device as claimed in claim 25 formed integrally with the laminated heat transfer device as claimed in claim 32.
43. A method of producing a laminated heat device, comprising
specifying a three-dimensional structure as a plurality of laminae;
producing the laminae from sheets of working material;
stacking the laminae according to a predetermined sequence with a guiding structure; and
connecting the laminae.
44. The method of producing a laminated heat transfer device of claim 43, wherein the stacking of laminae comprises folding a lamina upon itself.
45. The method of producing a laminated heat transfer device of claim 43, wherein the stacking of laminae comprises piling a lamina upon itself.
46. The method of producing a laminated heat transfer device of claim 43, wherein the stacking of laminae comprises a combination of folding and piling a lamina.
47. The method of producing a laminated heat transfer device of claim 43, wherein the laminated heat transfer device is a heat sink.
48. The method of producing a laminated heat transfer device of claim 43, wherein the laminated heat transfer device is a heat pipe.
49. A laminated heat transfer device, comprising a plurality of capillary structures formed from a plurality of lamina, the laminae having geometric features, the laminae being stacked according to a predetermined sequence.
50. The laminated heat transfer device of claim 49, further comprising two end plates.
51. The laminated heat transfer of device of claim 49, wherein the laminae being stacked comprises folding lamina upon itself.
52. The laminated heat transfer device of claim 49, wherein the laminae being stacked comprises piling lamina upon itself.
53. The laminated heat transfer device of claim 49, wherein the lamina being stacked comprises a combination of folding and piling lamina.
54. A laminated heat transfer device, comprising a plurality of capillary structures formed from a plurality of lamina, the laminae being of different sizes, the laminae being stacked according to a predetermined sequence.
55. The laminated heat transfer device of claim 54, further comprising two end plates.
56. The laminated heat transfer of device of claim 54, wherein the laminae being stacked comprises folding lamina upon itself.
57. The laminated heat transfer device of claim 54, wherein the laminae being stacked comprises piling lamina upon itself.
58. The laminated heat transfer device of claim 54, wherein the lamina being stacked comprises a combination of folding and piling lamina.
Description
CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. application Ser. No. 10/084,138, filed on Feb. 28, 2002, which claims priority under 35 USC 119(e) to U.S. application Ser. No. 60/282,170, filed on Apr. 9, 2001, the entire contents of which are incorporated by reference.

TECHNICAL FIELD

[0002] This invention relates to a laminated heat transfer device for cooling or thermal energy transport applications.

BACKGROUND

[0003] Heat is a by-product of electronic systems and the efficient removal of heat is key to preventing failure of electronics. For electronics, the most common methods of heat removal are heat sinks, heat-pipes, and Peltier devices.

[0004] Heat sinks (also known as heat-fins) are conduction-convection devices that remove heat by conducting heat away from a source and then eject the heat into a working fluid through convection. A heat sink balances the conduction and the convection processes so that conduction resistance is not too large, while convection resistance is small. In general, conduction resistance will increase as the fin's design is changed to yield a smaller convection resistance. Heat sinks can be either a ducting type or a porous type. A ducting-type heat sink channels the flow from a source so that the fluid flows over a maximum area of the heat sink. This is particularly important, for example, where the size of the heat sink is larger than the fan, and without the channeling function, less surface undergoes forced-convective cooling. In contrast, a porous-type heat sink does not channel the flow, but instead allows the fluid to flow to or from three directions. One example is a porous metallic foam, where the fluid flow can come from any of the three orthogonal directions, and as such, these heat sinks are useful in situations where the flow area is larger than the heat sink.

[0005] A heat-pipe is a heat-transfer device that relies on the evaporation and condensation of a working liquid. Normally, the liquid evaporates from the hot side (called evaporator side) and travels as a vapor to the cold side where it condenses back into liquid (called condenser side). The liquid must then be carried back to the evaporator side so that the cycle can start anew, which is typically done by using a porous wick and the capillary action of the liquid. As the heat of vaporization is typically very large, the heat-pipe is generally capable of a relatively large heat transfer rate. Indeed, heat-flux as high as 20 W/sq-cm has been reported for complex wicking structures.

[0006] A Peltier device is a thermoelectric device where heat is absorbed and rejected as an electric current flows through dissimilar conductors. Current Peltier devices have thermal back-diffusion.

SUMMARY

[0007] A laminated heat transfer device can be a laminated ducting-type heat sink, a laminated porous-type heat sink with an integrated base, a laminated heat-pipe, a laminated split-body Peltier device, or any combination of these.

[0008] A laminated ducting-type heat sink includes ducting channels for efficient air flow. Naturally convecting heat sinks include chimneys with varying or constant cross-sectional areas for flow-acceleration to provide fanless solutions. A ducting-type heat sink includes cross-linkages to use the spaces between the guiding vanes. This device is compatible and integrateable with the laminated heat-pipe and/or laminated split-body Peltier devices, described below.

[0009] A laminated porous-type heat sink includes an integrated base structure to minimize contact resistance. The depth of the base and its footprint varies with specific thermal requirement. This device accommodates a spatially varying porous structure to balance the convective and conductive thermal resistances. This device is also compatible and integrateable with the laminated heat-pipe and/or laminated split-body Peltier devices, described below.

[0010] A laminated heat-pipe varies in size and can have different wicking structures without using a sintering process. The wicking structure is an integral part of the overall heat-pipe to minimize thermal resistance. By stacking multiple laminae to form a hollow enclosure, the wicking structure comes from either stacking the laminae and/or aligning the laminae. This device is compatible and integrateable with the laminated heat sinks and/or the laminated split-body Peltier devices.

[0011] A laminated split-body Peltier device includes stacked multiple laminae such that each layer is an electrically conducting element of P-type and N-type materials. This device is compatible and integrateable with the laminated heat sinks and/or the laminated heat-pipe.

[0012] A method to produce the different implementations of a laminated heat transfer device is also provided. The method includes designing a three-dimensional structure into series of planar elements (laminae), which may or may not be self-repeating depending on the three-dimensional requirements; producing the laminae from sheets of working material by stamping, punching, etching, cutting, plating or other material forming process that are known in the art; stacking the laminae together according to a predetermined sequence. Each lamina may have separate parts which are functionally connected by diffusive bonding, welding, weaving, plating, bonding with inter-connective material, or any inter-connective method, or combination of inter-connective method and material forming process, or any combination thereof. The laminae can be formed from laminated working materials. The series of laminae can be connected in sequence, depending on the stacking process, or not connected in sequence.

[0013] The stacking process can use a guide structure, which can be integrated with the final product or not. Attachment is through thermal, pressure, sonic, chemical driven process, or any combination thereof. The attachment process can include additional interfacial material, and occur at the same time or after the stacking of some or all laminae.

[0014] In a first general aspect, a laminated heat transfer device includes a base and a vane formed from a plurality of laminae. Each lamina has a plurality of fins and a conduction core. The laminae are stacked according to a predetermined sequence.

[0015] The laminated heat transfer device may include some or all of the following features. The laminated heat transfer device also includes at least one guide rod to guide the stacking of laminae. The laminated heat transfer device also includes an alignment fixture to guide the stacking of laminae.

[0016] The stacking of laminae includes folding a lamina upon itself. Alternatively, the stacking of laminae includes piling a lamina upon itself. In another alternative, the stacking of laminae includes a combination of folding and piling a lamina.

[0017] The laminae are of equal size or varying size. Alternatively, the laminae are shaped like spokes of a wheel. In another alternative, at least one of the laminae is shaped like a web.

[0018] The fins of the heat sink form a spiral. The heat sink is a ducting-type heat sink.

[0019] In a second general aspect, a laminated heat transfer device includes a base and a porous structure formed from a plurality of first and second laminae. Each lamina has a plurality of shaped openings. The laminae are stacked according to a predetermined sequence.

[0020] The laminated heat transfer device may include some or all of the following features. The stacking of laminae comprises folding a lamina upon itself. Alternatively, the stacking of laminae includes piling a lamina upon itself. In another alternative, the stacking of laminae includes a combination of folding and piling a lamina.

[0021] The first and second laminae are alternately stacked and the laminae are stacked horizontally or vertically. The shaped openings of each lamina are uniformly or non-uniformly spaced. Alternatively, the shaped openings of each lamina are non-uniformly sized. In another alternative, the shaped openings of each lamina include the shapes of a rectangle, an oval, or a circle.

[0022] The laminae are of equal size or varying size. The laminated heat transfer device is a heat sink. The heat sink is a porous-type heat sink.

[0023] The laminated heat transfer device also includes two end plates. The openings of the primary and secondary laminae are different sizes in order to form grooves when the laminae are stacked together. Alternatively, the primary and secondary laminae are cut to form channels across the laminae toward the end plates when the laminae are stacked together.

[0024] The laminated heat transfer device can also include two plates. Each plate can be formed with a plurality of slits and positioned before a respective end plate.

[0025] The laminated heat transfer device is a heat pipe.

[0026] The laminated heat transfer device also includes two end plates. The openings of the primary and secondary laminae are the same size in order to form grooves when the laminae are stacked together. Alternatively, the primary and secondary laminae are cut to form channels across the laminae toward the end plates when the laminae are stacked together.

[0027] The laminated heat transfer device can also include two end plates. Each plate can be formed with a plurality of slits and positioned before a respective end plate.

[0028] The laminated heat transfer device is a heat pipe.

[0029] In a third general aspect, a laminated heat transfer device includes a base and a plurality of laminae formed with thermo-electric junctions. The laminae are stacked according to a predetermined sequence wherein a first group of laminae are attached to the base and a second group of laminae are thermally isolated.

[0030] The laminated heat transfer device may include some or all of the following features. The stacking of laminae includes folding a lamina upon itself. Alternatively, the stacking of laminae includes piling a lamina upon itself. In another alternative, the stacking of laminae comprises a combination of folding and piling a lamina.

[0031] The laminated heat transfer device is a split-body Peltier device.

[0032] In other aspects, a laminated heat transfer device includes combinations of ducting-type or porous-type laminated heat transfer devices formed integrally with porous-type laminated heat transfer device or split-body Peltier devices.

[0033] In another aspect, a method of producing a laminated heat device includes specifying a three-dimensional structure as a plurality of laminae, producing the laminae from sheets of working material, stacking the laminae according to a predetermined sequence with a guiding structure, and connecting the laminae.

[0034] The method of producing a laminated heat transfer device may include some or all of the following. The stacking of laminae includes folding a lamina upon itself. Alternatively, the stacking of laminae includes piling a lamina upon itself. In another alternative, the stacking of laminae includes a combination of folding and piling a lamina.

[0035] The laminated heat transfer device is a heat sink. Alternatively, the laminated heat transfer device is a heat pipe.

[0036] In another general aspect, a laminated heat transfer device includes a plurality of capillary structures formed from a plurality of lamina. The laminae have geometric features. The laminae are stacked according to a predetermined sequence.

[0037] The laminated heat transfer device may include some or all of the following features. The laminated heat transfer device also includes two end plates. Stacking the laminae includes folding lamina upon itself. Alternatively, stacking the laminae includes piling lamina upon itself. In another alternative, stacking the lamina includes a combination of folding and piling lamina.

[0038] In another general aspect, a laminated heat transfer device includes a plurality of capillary structures formed from a plurality of lamina. The laminae are of different sizes. The laminae are stacked according to a predetermined sequence.

[0039] The laminated heat transfer device may include some or all of the following features. The laminated heat transfer device also includes two end plates. Stacking the laminae includes folding lamina upon itself. Alternatively, stacking the laminae includes piling lamina upon itself. In another alternative, stacking the laminae includes a combination of folding and piling lamina.

[0040] The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

[0041] Exemplary implementations are depicted in the attached figures, in which:

[0042]FIG. 1a illustrates an implementation of a laminated ducting-type heat sink;

[0043]FIG. 1b is an exploded perspective view of an individual lamina of FIG. 1a;

[0044]FIG. 1c shows illustrates an implementation of a laminated ducting-type heat sink with cross-linkages;

[0045]FIG. 2a illustrates a laminated porous-type heat sink with an integrated base;

[0046]FIG. 2b is a cross-sectional view of the porous structure of FIG. 2a;

[0047]FIG. 2c is an exploded perspective view of an individual lamina of FIG. 2a;

[0048]FIG. 2d is another exploded perspective view of the individual lamina of FIG. 2a;

[0049]FIG. 2e is an exploded perspective view of an individual lamina of a porous-type heat sink with varying pores;

[0050]FIG. 3a illustrates an implementation of a laminated ducting-type heat sink for natural convection applications;

[0051]FIG. 3b is an exploded perspective view of an individual lamina of FIG. 3a;

[0052]FIG. 4a illustrates a laminated heat-pipe;

[0053]FIG. 4b is an exploded perspective view of an individual lamina of the laminated heat-pipe with an integrated wicking structure;

[0054]FIG. 4c is an exploded perspective view of the laminated heat-pipe with another integrated wicking structure;

[0055]FIG. 4d is a close-up view of laminae of the laminated heat-pipe with a wicking structure;

[0056]FIG. 5a illustrates a laminated split-body Peltier device;

[0057]FIG. 5b is an exploded perspective view of an individual lamina of the device of FIG. 5a;

[0058]FIG. 6a illustrates an implementation of a porous heat sink with an integrated heat-pipe;

[0059]FIG. 6b illustrates an implementation of a split-body Peltier device with an integrated heat-pipe;

[0060]FIG. 6c illustrates a combination of a laminated heat pipe and a laminated heat sink in which the cavity and capillary structure extend from the base to the fins of the heat sink;

[0061]FIG. 6d illustrates another combination of a laminated heat pipe and a laminated heat sink in which an additional extended surface protrudes from the fins of the heat sink;

[0062]FIGS. 7a and 7 b illustrate the implementation of the laminated porous type heat sink of FIG. 2a in which the laminae are folded to form the three-dimensional structure of the device; and

[0063]FIGS. 7c and 7 d illustrate the implementation of the laminated heat pipe of FIG. 4a in which the laminae are folded to form the three-dimensional structure of the device.

[0064] Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

[0065]FIG. 1a illustrates an implementation of a laminated ducting-type heat sink 100. Alternatively, the heat sink could have a spiral-vane configuration. The heat sink 100 includes a base 110 and the vanes 130. The base 110 conducts heat from the source (not shown), such as an electronic device, to the vanes 130. The base 110 is made out of thermally-conductive materials, such as copper, and its thickness is a function of the applied heat-flux and the airflow over the vanes. In general, the larger the applied heat-flux, the thicker the base to spread the heat over the base. Typically, the base 110 is approximately 5 mm.

[0066]FIG. 1b shows two guiding rods 111, which are functionally attached to the base 110 through interference fitting, chemical bonding, soldering, brazing, or any other similar techniques known in the art. The guiding rods 111 are made of metals or polymers, and guide the stacking of the laminae 120 through the guiding holes 121. Each lamina has fins 122 and a conduction core 123, so that the heat conducts from the base 110 through the conduction core 123 toward the fins 122. As the conduction core 123 reduces the overall thermal resistance, its diameter needs to be sufficiently large to enable the heat to effectively diffuse from the base 110 to the top-most lamina with minimal resistance. While the exact diameter will depend on the flow rate impinging on the structure, the diameter of the conduction core 123 is generally between 5 and 20 mm.

[0067] The fins 122 eject heat into the working fluid. The width of the fins is generally less than 2 mm. The base of the fins 122 may touch at the conduction core 123 or may be spaced apart. In addition to ejecting heat, the fins 122 of the laminae 120 form the vanes 130 of the final product 100 to provide radial ducting of the working fluid. The laminae 120 may have similar or different shapes, or depending on the final product 100. Each lamina 120 is a thermal conductor and is preferably made from metal. The laminae 120 can be obtained by stamping, punching, etching, and/or plating processes from sheets of working materials. The thickness of each lamina is determined by the lamina production process. For example, a stamping process is applied for copper material with a thickness of approximately 1 mm or less. However, the thinner the working material, the more laminae needed to complete a product. The balance between tool-life, production rate, and product quality is an operational issue determined on the production floor. In this implementation, the laminae 120 are stacked and functionally joined together to yield the final product 100. The joining between the laminae 120 and with the base 110 can be accomplished with soldering, brazing, welding, plating, chemical bonding, diffusion bonding, or any similar process known in the art. The stacking process can be performed through the aforementioned guiding rods 111 or through an alignment fixture (not shown). Furthermore, the stacking and joining can be accomplished in one or multiple processes.

[0068] Alternatively, the laminae are formed by a single lamina that is then folded upon itself to form the three-dimensional structure of the device. Laminae 120 formed of thermally conductive materials, for example, copper or aluminum, are used in the folded laminae implementation. Alternatively, the laminae are piled upon each other to form the three-dimensional structure of the device. Alternatively, a combination of folding and piling can be used to form the three-dimensional structure of the device.

[0069] Another implementation of the laminated ducting-type heat sink includes cross-linkages between the guiding vanes. As shown in FIG. 1c, laminae 140 with cross-linkages 141 are introduced periodically to render a structure that effectively utilizes the space between the guiding vanes. These cross-linkages 141 increase the number of heat conduction paths and the amount of convective surface area.

[0070]FIG. 2a illustrates a laminated porous-type heat sink with an integrated base. Heat sink 200 includes a base 210 and a porous structure 220. As shown in FIG. 2b, the porous structure allows the working fluid to pass through in three directions. As shown in FIG. 2c, this is obtained by stacking together primary laminae 221 and secondary laminae 222 having different opening designs so that the base 210 is formed as an integral part of the assembly 200. Alternatively, the primary and secondary laminae 221, 222 can be stacked perpendicular to the base (FIG. 2d). The openings in the laminae are rectangular, but can be oval, circular, or other shape. In addition, the openings on the individual laminae can be spatially non-uniform to provide a heat sink with spatially varying porosity (FIG. 2e). This configuration allows optimization of the heat-conduction path relative to the fluid flow. In general, the thickness, materials and process of stacking and joining the laminae are similar to those described above.

[0071] Alternatively, the lamina is folded upon itself to form laminae layers to form the device structure. In another alternative, the laminae is piled upon itself to form the three-dimensional structure of the device. Alternatively, a combination of folding and piling can be used to form the three-dimensional structure of the device.

[0072] One alternative, shown in FIG. 3a, is a laminated ducting-type heat sink 300 for natural convection applications. This heat sink 300 includes a base 310, an air intake 320, a converging duct 330, guiding vanes 340 and a conduction rod 350. In operation, a heat source (not shown) is applied to the bottom of the base 310, which conducts the heat to the guiding vanes 340 and the conduction rod 350. This conduction rod 350 should be sufficiently large in diameter to allow heat to conduct upwards, but sufficiently small to yield a large surface area to volume ratio. In general, the conduction rod 350 is approximately 3 to 5 mm in diameter, and this rod may be straight or ribbed (not shown) in order to maximize the heat transfer efficiency to the surrounding air. The conduction rod 350 is situated directly above the heat-source so most of the heat will travel up this conduction rod 350 and to the adjacent air, which then rises due to the buoyancy force. As the air rises, it is accelerated by the converging duct 330, which then entrains air at the intake 320 by creating a low-pressure condition. The guiding vanes 340 serve the dual purpose of radially directing air inward, while conducting heat from the base 310 to the converging duct 330, which further heats the air and increases the flow-rate within. The converging duct 330 should be a thermally conducting material, preferably a metal, such as copper or aluminum. In addition, a fan (not shown) can be placed on top of the heat sink to provide forced convective cooling, in which case, the guiding vanes 340 also serve the function of heat fins. As described above, the heat sink 300 is obtained by stacking and joining together the inlet laminae 321 and the duct laminae 331 as shown in FIG. 3b. By stacking together the inlet laminae 321, the air intake 320 and the guiding vanes 340 are created, and above these inlet laminae 321, the duct laminae 331 are stacked and functionally joined to render the converging duct structure 330.

[0073] Alternatively, the lamina is folded upon itself to form laminae layers to form the device structure. In another alternative, the lamina is piled upon itself to form the three-dimensional structure of the device. Alternatively, a combination of folding and piling of the lamina can be used to form the three-dimensional structure of the device.

[0074] In general, the thickness, materials and process of stacking and joining the laminae are similar to those described above, with the exception that the duct laminae 331 need to be thin to render a smooth curvature. In general, such laminae are approximately 0.5 mm in thickness, although thicker laminae can be accommodated by the appropriate use of chamfers. As before, the stacking process can be performed through guiding rods 311 or through an appropriate alignment fixture (not shown).

[0075] Another implementation is the laminated heat-pipe shown in FIG. 4a. This heat-pipe 400 includes alternately stacked primary 410 and secondary 420 laminae, and is terminated at the two ends by the end plates 430. Alternatively, the lamina is folded upon itself to form laminae layers to form the device structure. In another alternative, the lamina is piled upon itself to form the three-dimensional structure of the device. Alternatively, a combination of folding and piling of the lamina can be used to form the three-dimensional structure of the device.

[0076] Both the primary and secondary laminae 410, 420 have central openings, and thus render these laminae, rings. The openings may be rectangular, circular, oval, or other shape, and the amount of material remaining in the laminae 411, 421 should be sufficient to enable sealing between the laminae. In addition, the openings on the primary and secondary laminae 410, 420 are slightly different in size (approximately 0.2 to 1 mm) so that capillary grooves 440 are formed when the laminae are stacked together (FIG. 4b). These capillary grooves 440 function as the wick and circulate condensed liquid in the in-plane direction. The whole unit is sealed by functionally joining the two laminae 410, 420 along with the end plates 430. The sealing can be done after, during or before the heat-pipe is charged with liquid, and in the case of the latter, a valve (not shown) would be provided on the end plate. The sealing process can be a pressure and/or temperature activated process involving brazing, soldering, welding, chemical bonding, diffusion bonding or any other similar methods known in the art.

[0077] To further improve on the circulation process, the primary and secondary laminae 410, 420 include features 412, 422 that are aligned to form capillary channels 450 across the laminae and toward the two end plates 430, when the laminae are stacked together. This is shown in FIG. 4c where the two additional plates 460 with slits can be added before the end plates 430 to improve circulation. The capillary channels 450 should be sufficiently small to enable flow, but not too small to prevent the accurate alignment between the laminae. In general, these channels are approximately 0.1 to 0.5 mm in diameter. In addition, the cuts, as shown in FIG. 4d, can be increased (widened) to increase capillary action in the channels. Finally, the thickness, materials and process of stacking and joining the laminae are similar to those described in the above implementation. Alternatively, as described above, a combination of folding and piling the lamina can be used to form the three-dimensional structure of the device.

[0078] Referring to FIG. 5a, a laminated split-body Peltier device 500 includes laminae 510 having thermoelectric junctions, such that one group of junctions 511 is functionally attached to the base 520, while a second group of junctions 512 is thermally isolated by distance to render a split-body configuration. In operation, group 512 is the hot junction, while group 511 is the cold junction. Attachment to the base can be accomplished by a chemical agent (curable adhesive), diffusive bonding, welding, soldering or any similar methods known in the art. The base 515 can be a thermal conductor and electrically insulated from the laminae 510 through oxides or polymers (not shown). Each lamina is approximately 0.2 to 2 mm thick and can be formed from N-type and P-type materials in a Z shape, obtained from sheets of dissimilar electrical conductors (metallic or polymeric) through stamping, etching, plating, and/or punching. Junctions 511, 512 can be formed by functionally joining together the P-type 513 and N-type 514 materials through welding, plating, soldering, diffusive bonding, and/or any other similar methods known in the art.

[0079] With the exception of the two ends 516, each individual lamina is electrically insulated by using an oxide or a polymer coating (not shown) and are stacked/joined together similar to the methods discussed for the first embodiment. The two ends 516 of each lamina are not insulated to enable electric current to pass through after the laminae are joined together. Two basic stacking arrangements are possible depending on whether the individual lamina is electrically connected in series or parallel. Electrical wires 517 are then functionally attached to the two ends 516 for connection with an external power source.

[0080] Alternatively, the stacking can be folding the lamina upon itself to form laminae layers to form the device structure, or piling the lamina upon itself, or a combination of folding and piling the lamina.

[0081] The devices shown in FIGS. 1-5 can be combined together in different ways to suit the final performance target. For example, as shown in FIG. 6a, the laminated heat sink and the laminated heat-pipe can be form one integral unit. Alternatively, the laminated heat-pipe and the laminated split-body Peltier device can form an integral unit (FIG. 6b). In another example, as shown in FIG. 6c, a combination of a laminated heat pipe and a laminated heat sink form an integrated heat pipe-heat sink device. The cavity and capillary structure extend from the base to the fins of the heat sink. Alternatively, the extended surface can protrude from the fins, as shown in FIG. 6d.

[0082] Referring to FIGS. 7a-7 d, the laminae are folded to form the three-dimensional structure of the device.

[0083] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made. Accordingly, other implementations are within the scope of the following claims.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US6842342 *Sep 12, 2003Jan 11, 2005Leohab Enterprise Co., Ltd.Heat sink
US7312985 *Mar 7, 2003Dec 25, 2007Lg Electronics Inc.Cooler of notebook personal computer and fabrication method thereof
US7650931Jun 9, 2008Jan 26, 2010Covergence Technologies LimitedVapor augmented heatsink with multi-wick structure
US20090323285 *Jun 23, 2009Dec 31, 2009Sony CorporationHeat transport device and electronic apparatus
US20120080166 *Oct 4, 2011Apr 5, 2012Cooler Master Co., Ltd.Liquid-cooling heat sink and heat exchanger thereof
WO2004088761A1 *Mar 31, 2004Oct 14, 2004Lucea AgLight-emitting panel
WO2006017301A2 *Jul 11, 2005Feb 16, 2006Thorrn Micro Technologies IncMicro-channel heat sink
Classifications
U.S. Classification165/104.33, 257/E23.103
International ClassificationF28F3/02, B21D53/04, H01L23/367, B23P15/26
Cooperative ClassificationB23P15/26, B21D53/04, B23P2700/12, B23P2700/10, F28F3/02, H01L23/3672
European ClassificationF28F3/02, B21D53/04, B23P15/26, H01L23/367F
Legal Events
DateCodeEventDescription
Aug 16, 2002ASAssignment
Owner name: CONVERGENCE TECHNOLOGIES, LTD., HONG KONG
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SIU, WING MING;REEL/FRAME:013210/0413
Effective date: 20020627