Cold plate and electronic device

Abstract

A cold plate is configured to be thermally coupled to a heat source of a motherboard. The cold plate has an inlet channel, a heat exchange chamber, a peripheral channel and an outlet channel. The heat exchange chamber communicates with the inlet channel. The peripheral channel communicates with the inlet channel, and surrounds the heat exchange chamber. The outlet channel communicates with the heat exchange chamber and the peripheral channel.

Description

Technical Field

[0001] This invention relates to a cold plate and an electronic device. Prior Technology

[0002] Liquid metal is a relatively new thermal interface material with a high thermal conductivity. However, due to its high electrical conductivity and fluidity, if proper protective measures are not taken and liquid metal spills from the wafer and comes into contact with surrounding electronic components, damage may occur.

[0003] To prevent liquid metal spillage, a common solution is to coat the chip with resin, which protects the surrounding components and also acts as a barrier to prevent liquid metal from spilling out of the chip area. Adding a heatsink module then seals the liquid metal between the chip and the heatsink.

[0004] While adding a resin enclosure can significantly reduce the likelihood of overflow, if the resin surface becomes uneven during coating due to factors such as surface roughness around the chip, insufficient sealing between the resin and the heat dissipation module can allow liquid metal to leak out from tiny gaps. Therefore, researchers in this field are currently working to address these issues. Summary of the Invention

[0005] The present invention provides a cold plate and an electronic device that can prevent liquid metal from overflowing from the gap between the heat dissipation module and the resin, so as to ensure that the liquid metal does not come into contact with the electronic components around the chip.

[0006] One embodiment of the present invention discloses a cold plate for thermally coupling to a heat source on a motherboard through a thermal interface material. The cold plate has a liquid inlet channel, a heat exchange chamber, a peripheral flow channel, and a liquid outlet channel. The heat exchange chamber is connected to the liquid inlet channel. The peripheral flow channel is connected to the liquid inlet channel and surrounds the heat exchange chamber. The liquid outlet channel connects the heat exchange chamber and the peripheral flow channel.

[0007] Another embodiment of the present invention discloses an electronic device comprising a motherboard module. The motherboard module includes a motherboard, a thermal interface material, and a cold plate. The motherboard includes a circuit board and a heat source, the heat source being disposed on the circuit board. The cold plate is thermally coupled to the heat source of the motherboard through the thermal interface material. The cold plate has a liquid inlet channel, a heat exchange chamber, a peripheral flow channel, and a liquid outlet channel. The heat exchange chamber is connected to the liquid inlet channel. The peripheral flow channel is connected to the liquid inlet channel and surrounds the heat exchange chamber. The liquid outlet channel connects the heat exchange chamber and the peripheral flow channel.

[0008] According to the cold plate and electronic device disclosed in the above embodiments, the heat exchange chamber and the peripheral flow channel of the cold plate are both connected to the liquid inlet channel and the liquid outlet channel, and the peripheral flow channel surrounds the heat exchange chamber, allowing the low-temperature working fluid entering the cold plate from the liquid inlet channel to flow in the peripheral flow channel. Therefore, the outer heat interface material can solidify into a solid state when it flows to the part where the peripheral flow channel of the cold plate is located, forming a wall to prevent the inner heat interface material from continuing to flow outward, thus ensuring that the heat interface material does not come into contact with the electronic components around the heat source.

[0009] The above description of the content of this invention and the following description of the embodiments are used to demonstrate and explain the principles of this invention, and to provide a further explanation of the scope of the patent application of this invention. Simple Explanation of the Diagram

[0010] Figure 1 shows a partial cross-sectional view of an electronic device according to some embodiments of the present invention. Figure 2 shows an exploded cross-sectional view of a motherboard module according to some embodiments of the present invention. Figure 3 shows a top view of a cold plate according to some embodiments of the present invention. Figure 4 shows a schematic diagram of the cold plate of the motherboard module of some embodiments of the present invention placed on the motherboard. Figure 5 shows a schematic diagram of the flow of thermal interface material on the motherboard after the cold plate is pressed down in some embodiments of the present invention. Implementation

[0011] Please refer to Figure 1, which shows a partial cross-sectional view of an electronic device 1 according to some embodiments of the present invention. The structural features of Figure 1 can be applied to other embodiments of the present invention.

[0012] Electronic device 1 includes a motherboard module 2. In some embodiments, electronic device 1 may also include a cabinet 3 and a carrier 4. The carrier 4 is, for example, a tray or bracket. The motherboard module 2 is configured to be mounted within the cabinet 3 via the carrier 4, but is not limited thereto. In other embodiments, the motherboard module may also be mounted in other types of housings.

[0013] Figure 2 shows an exploded cross-sectional view of the motherboard module 2 according to some embodiments of the present invention. Figure 3 shows a top view of the cold plate 30 according to some embodiments of the present invention. The structural features of Figures 2 and 3 can be applied to other embodiments of the present invention.

[0014] The motherboard module 2 includes a motherboard 10, a thermal interface material 20, and a cold plate 30. The motherboard 10 includes a circuit board 11 and a heat source 12, with the heat source 12 disposed on the circuit board 11. The cold plate 30 is thermally coupled to the heat source 12 of the motherboard 10 through the thermal interface material 20. The cold plate 30 has a liquid inlet channel 31, a heat exchange chamber 32, an outer flow channel 33, and a liquid outlet channel 34. The heat exchange chamber 32 is connected to the liquid inlet channel 31. The outer flow channel 33 is connected to the liquid inlet channel 31 and surrounds the heat exchange chamber 32. The liquid outlet channel 34 connects the heat exchange chamber 32 and the outer flow channel 33.

[0015] In some embodiments, the thermal interface material 20 may be a metal that can change phase between liquid and solid states, and has thermal conductivity and high electrical conductivity.

[0016] In some embodiments, the heat source 12 of the motherboard 10 may be a central processing unit (CPU) or a graphics processing unit (GPU). In some embodiments, the motherboard 10 may also include a plurality of on-board components 13 disposed on the circuit board 11 and located around the heat source 12. The on-board components 13 may be electronic components other than the CPU or GPU, such as capacitors.

[0017] In some embodiments, the cold plate 30 further has a thermal coupling surface 35 and a contact surface 36. The thermal coupling surface 35 corresponds to (e.g., opposite to) the heat exchange chamber 32 and is used to thermally couple to the heat source 12 of the motherboard 10 through the thermal interface material 20. The contact surface 36 is located around the thermal coupling surface 35 and corresponds to (e.g., opposite to) the peripheral flow channel 33. The contact surface 36 is configured to correspond to the on-board components 13 of the motherboard 10.

[0018] In some embodiments, the thermal coupling surface 35 and the contact surface 36 of the cold plate 30 are coplanar, but this is not a limitation. In other embodiments, the thermal coupling surface and the contact surface may not be coplanar.

[0019] In some embodiments, the cold plate 30 has a groove 37 that separates the peripheral flow channel 33 from the heat exchange chamber 32. The groove 37 is used to accommodate a portion of the heat interface material 20. In some embodiments, the groove 37 is annular, but not limited thereto. In other embodiments, the groove may not be annular, and there may be multiple grooves arranged in a ring.

[0020] In some embodiments, the motherboard module 2 further includes an annular insulating member 40, which is disposed between the contact surface 36 of the on-board components 13 and the cold plate 30 and blocks the thermal interface material 20. In some embodiments, the annular insulating member 40 is elastic and is made of, for example, resin. In some embodiments, the annular insulating member 40 may be pre-positioned on the contact surface 36 of the cold plate 30 or on the on-board components 13 of the motherboard 10 before the cold plate 30 is assembled to the motherboard 10.

[0021] In some embodiments, the motherboard 10 further includes an annular frame 14 disposed on the circuit board 11 and in contact with the outer edge of the heat source 12, with the orthographic projection of the groove 37 entirely located on the annular frame 14. That is, the groove 37 is located directly above the annular frame 14. The annular frame 14 contacts the annular insulator 40. In some embodiments, the opposite sides of the annular insulator 40 contact the components 13 on the board, the contact surface 36, and the annular frame 14, respectively.

[0022] In some embodiments, the peripheral flow channel 33 of the cold plate 30 is not directly connected to the heat exchange chamber 32. In some embodiments, the liquid inlet channel 31 of the cold plate 30 has a first branch 311 and a second branch 312, the first branch 311 being connected to the heat exchange chamber 32 and the second branch 312 being connected to the peripheral flow channel 33. In some embodiments, the liquid inlet channel 31 of the cold plate 30 also has a main inlet 313, the first branch 311 being connected to the main inlet 313 and the second branch 312 being connected to the main inlet 313. In some embodiments, the liquid outlet channel 34 of the cold plate 30 has a first outlet 341 and a second outlet 342, the first outlet 341 being connected to the heat exchange chamber 32 and the second outlet 342 being connected to the peripheral flow channel 33. In some embodiments, the liquid outlet channel 34 of the cold plate 30 further has a main confluence 343, the first outlet 341 is also connected to the main confluence 343, and the second outlet 342 is also connected to the main confluence 343.

[0023] Next, the process of assembling the cold plate 30 onto the motherboard 10 will be described below. First, as shown in Figure 2, the thermal interface material 20 is placed on the heat source 12 and the annular frame 14, wherein the thermal interface material 20 can be liquid or solid.

[0024] Next, please refer to Figure 4. Figure 4 shows a schematic diagram of the cold plate 30 of the motherboard module 2 of some embodiments of the present invention placed on the motherboard 10. The structural features of Figure 4 can be applied to other embodiments of the present invention. As shown in Figure 4, the cold plate 30 is placed on the motherboard 10 such that the thermal coupling surface 35 of the cold plate 30 contacts the side of the thermal interface material 20 away from the heat source 12, and the opposite sides of the annular insulating member 40 contact the contact surface 36 of the cold plate 30, the annular frame 14, and the components 13 on these boards, respectively. At this time, the cold plate 30 is in a pressure-waiting state, the liquid or solid thermal interface material 20 is not compressed, and a gap G is formed by maintaining a distance from the annular insulating member 40. If the thermal interface material 20 is solid at this time, it is then heated to become liquid.

[0025] Next, please refer to Figure 5. Figure 5 shows a schematic diagram of the flow of thermal interface material 20 on the motherboard 10 after the cold plate 30 is pressed down in some embodiments of the present invention. The structural features of Figure 5 can be applied to other embodiments of the present invention. As shown in Figure 5, an external force is applied to the cold plate 30 in the direction of the heat source 12 to move the cold plate 30, so that the cold plate 30 changes from a state to a state under pressure. At this time, part of the liquid thermal interface material 20 flows outward into the gap G and onto the contact surface 36 of the cold plate 30 facing away from the peripheral flow channel 33, and another part of the liquid thermal interface material 20 flows into the groove 37 of the cold plate 30, and the annular insulating member 40 stops the thermal interface material 20. Thus, the process of assembling the cold plate 30 onto the motherboard 10 is completed.

[0026] In the above embodiment, the heat exchange chamber 32 and the peripheral flow channel 33 of the cold plate 30 are both connected to the liquid inlet channel 31 and the liquid outlet channel 34. The peripheral flow channel 33 surrounds the heat exchange chamber 32, allowing the low-temperature working fluid entering the cold plate 30 from the liquid inlet channel 31 to flow in the peripheral flow channel 33. Therefore, the outer heat interface material 20 can solidify into a solid state when it flows to the part of the peripheral flow channel 33 of the cold plate 30, forming a wall to prevent the inner heat interface material 20 from continuing to flow outward. Thus, it can be ensured that the heat interface material 20 will not come into contact with the plate components 13 around the heat source 12.

[0027] Furthermore, in the above embodiment, by means of the main inlet portion 313 of the liquid inlet channel 31 being connected to the heat exchange chamber 32 and the peripheral flow channel 33 through the first branch portion 311 and the second branch portion 312 respectively, and the heat exchange chamber 32 and the peripheral flow channel 33 being connected to the main confluence portion 343 through the first outlet portion 341 and the second outlet portion 342 of the liquid outlet channel 34 respectively, the heat exchange chamber 32 and the peripheral flow channel 33 can be arranged in parallel. Therefore, the working fluid entering the peripheral flow channel 33 will not absorb heat from the heat source 12, so as to ensure that the working fluid in the peripheral flow channel 33 remains at a low temperature and the heat interface material 20 can solidify.

[0028] It should be noted that the heat exchange chamber 32 and the peripheral flow channel 33 are not limited to being arranged in parallel. In other embodiments, the heat exchange chamber and the peripheral flow channel may be arranged in series, and the liquid inlet channel, the peripheral flow channel, the heat exchange chamber, and the liquid outlet channel are connected sequentially. In another embodiment, the heat exchange chamber and the peripheral flow channel may be independent of each other and have no communication relationship. That is, the cold plate may not have a main inlet and a main confluence, and the path formed by the first branch, the heat exchange chamber, and the first outlet may be independent of the path formed by the second branch, the peripheral flow channel, and the second outlet.

[0029] In the above embodiments, the configuration in which the orthographic projection of the groove 37 is completely located on the annular frame 14 ensures that the position of the groove 37 does not sacrifice the contact area of ​​the thermal coupling surface 35 between the heat source 12 and the cold plate 30, thereby avoiding affecting the heat exchange efficiency between the heat source 12 and the cold plate 30.

[0030] It should be noted that the orthographic projection of the groove 37 is not limited to being entirely located on the annular frame 14. In other embodiments, if the arrangement of the groove does not excessively affect the heat exchange efficiency between the heat source and the cold plate, the orthographic projection of the groove may be partially or completely located on the heat source. That is, the orthographic projection of the groove may be partially located on the annular frame, or the orthographic projection of the groove may not be located on the annular frame at all. On the other hand, the annular frame 14 is an optional element and may be omitted in other embodiments.

[0031] In some embodiments, the groove 37 of the cold plate 30, which separates the peripheral flow channel 33 and the heat exchange chamber 32, not only accommodates a portion of the heat exchange material 20 but also reduces heat exchange between the heat exchange chamber 32 and the peripheral flow channel 33. This further ensures that the working fluid in the peripheral flow channel 33 is at a sufficiently low temperature to allow the heat exchange material 20 to solidify. It should be noted that the groove 37 is an optional structure and may be omitted in other embodiments.

[0032] In the above embodiments, the annular insulating member 40, with its opposite sides contacting the contact surface 36 of the cold plate 30, the annular frame 14, and the on-plate components 13, can further isolate the thermal interface material 20 from the on-plate components 13. It should be noted that the annular insulating member 40 is an optional component and may be omitted in other embodiments.

[0033] According to the cold plate and electronic device disclosed in the above embodiments, the heat exchange chamber and the peripheral flow channel of the cold plate are both connected to the liquid inlet channel and the liquid outlet channel, and the peripheral flow channel surrounds the heat exchange chamber, allowing the low-temperature working fluid entering the cold plate from the liquid inlet channel to flow in the peripheral flow channel. Therefore, the outer heat interface material can solidify into a solid state when it flows to the part where the peripheral flow channel of the cold plate is located, forming a wall to prevent the inner heat interface material from continuing to flow outward, thus ensuring that the heat interface material does not come into contact with the components on the plate around the heat source.

[0034] Furthermore, by connecting the main inlet section of the liquid inlet channel to the heat exchange chamber and the peripheral flow channel through the first branch and the second branch respectively, and connecting the heat exchange chamber and the peripheral flow channel to the main confluence section through the first outlet section and the second outlet section respectively, the heat exchange chamber and the peripheral flow channel can be configured in parallel. Therefore, the working fluid entering the peripheral flow channel will not absorb heat from the heat source, ensuring that the working fluid in the peripheral flow channel remains at a low temperature, which allows the heat interface material to solidify.

[0035] Furthermore, the grooves in the cold plate separate the outer flow channel and the heat exchange chamber. In addition to accommodating some of the heat exchange material, they also reduce the heat exchange between the heat exchange chamber and the outer flow channel, thereby ensuring that the working fluid in the outer flow channel is at a sufficiently low temperature so that the heat exchange material can solidify.

[0036] Although the present invention has been disclosed above with reference to the preferred embodiments described above, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of patent protection of the present invention shall be determined by the scope of the claims attached to this specification.

[0037] 1: Electronic devices 2: Motherboard Module 3: Server rack 4: Load-bearing components 10: Motherboard 11: Circuit Board 12: Heat source 13: Components on the board 14: Ring frame 20: Thermal interface materials 30: Cold Plate 31: Liquid Inlet Channel 311: First Branch 312: Second Branch 313: Main inflow section 32: Heat exchange chamber 33: Peripheral flow channel 34: Liquid outlet channel 341: First outflow section 342: Second outflow section 343: Main Convergence Section 35: Thermal coupling surface 36: Contact surface 37: Trench 40: Ring-shaped insulator G: Gap

Claims

1. A cold plate for thermally coupling to a heat source on a motherboard through a thermal interface material, the cold plate having: a liquid inlet channel; a heat exchange chamber communicating with the liquid inlet channel; a peripheral flow channel communicating with the liquid inlet channel and surrounding the heat exchange chamber; and a liquid outlet channel communicating with the heat exchange chamber and the peripheral flow channel.

2. The cold plate as claimed in claim 1, wherein the cold plate has a thermal coupling surface and a contact surface, the thermal coupling surface corresponding to the heat exchange chamber, the thermal coupling surface being used to thermally couple to the heat source of the motherboard through the thermal interface material, the contact surface being located around the thermal coupling surface and corresponding to the peripheral flow channel, the contact surface being configured to correspond to a plurality of on-board components of the motherboard.

3. The cold plate as claimed in claim 1, wherein the cold plate further has a groove that separates the peripheral flow channel and the heat exchange chamber, the groove being used to accommodate a portion of the heat interface material.

4. The cold plate as described in claim 3, wherein the groove is annular.

5. The cold plate as described in claim 2, wherein the thermal coupling surface and the contact surface are coplanar.

6. The cold plate as claimed in claim 1, wherein the liquid inlet channel of the cold plate has a first branch and a second branch, the first branch being connected to the heat exchange chamber and the second branch being the peripheral flow channel.

7. The cold plate as claimed in claim 1, wherein the liquid outlet channel of the cold plate has a first outlet portion and a second outlet portion, the first outlet portion being connected to the heat exchange chamber and the second outlet portion being connected to the peripheral flow channel.

8. The cold plate as claimed in claim 6, wherein the liquid inlet channel of the cold plate further has a main inlet portion, the first branch portion is further connected to the main inlet portion, and the second branch portion is further connected to the main inlet portion.

9. The cold plate as claimed in claim 7, wherein the liquid outlet channel of the cold plate further has a main manifold, the first outlet is also connected to the main manifold, and the second outlet is also connected to the main manifold.

10. The cold plate as described in claim 1, wherein the peripheral flow channel is not in direct communication with the heat exchange chamber.

11. An electronic device comprising: a motherboard module, comprising: a motherboard including a circuit board and a heat source disposed on the circuit board; a thermal interface material; and a cold plate thermally coupled to the heat source of the motherboard through the thermal interface material, the cold plate having: a liquid inlet channel; a heat exchange chamber communicating with the liquid inlet channel; a peripheral flow channel communicating with the liquid inlet channel and surrounding the heat exchange chamber; and a liquid outlet channel communicating with the heat exchange chamber and the peripheral flow channel.

12. The electronic device as claimed in claim 11, wherein the cold plate has a groove that separates the peripheral flow channel and the heat exchange chamber, the groove being used to accommodate a portion of the heat interface material.

13. The electronic device as claimed in claim 12, wherein the motherboard module further includes an annular insulating member, the motherboard further includes a plurality of on-board components located around the heat source, the cold plate has a contact surface corresponding to the peripheral flow channel, and the annular insulating member is disposed between the on-board components and the contact surface and blocks the heat interface material.

14. The electronic device as claimed in claim 13, wherein the annular insulating member is resilient.

15. The electronic device as claimed in claim 13, wherein the motherboard further includes an annular frame disposed on the circuit board and in contact with the outer edge of the heat source, the orthographic projection of the trench being entirely located on the annular frame, and the annular frame contacting the annular insulator.

16. The electronic device as claimed in claim 15, wherein the opposite sides of the annular insulator contact the on-board components, the contact surface, and the annular frame, respectively.

17. The electronic device as claimed in claim 12, wherein the trench is annular.

18. The electronic device as claimed in claim 11, wherein the cold plate further has a thermal coupling surface and a contact surface, the thermal coupling surface corresponding to the heat exchange chamber, the thermal coupling surface being used to thermally couple to the heat source of the motherboard through the thermal interface material, the contact surface being located around the thermal coupling surface and corresponding to the peripheral flow channel, the contact surface being configured to correspond to a plurality of on-board components of the motherboard.

19. The electronic device as claimed in claim 18, wherein the thermal coupling surface and the contact surface are coplanar.

20. The electronic device as claimed in claim 11, wherein the liquid inlet channel of the cold plate has a first branch and a second branch, the first branch communicating with the heat exchange chamber and the second branch being the peripheral flow channel.

21. The electronic device as claimed in claim 11, wherein the liquid outlet channel of the cold plate has a first outlet and a second outlet, the first outlet communicating with the heat exchange chamber and the second outlet communicating with the peripheral flow channel.

22. The electronic device as claimed in claim 20, wherein the liquid inlet channel of the cold plate further has a main inlet portion, the first branch portion is further connected to the main inlet portion, and the second branch portion is further connected to the main inlet portion.

23. The electronic device as claimed in claim 21, wherein the liquid outlet channel of the cold plate further has a main manifold, the first outlet is further connected to the main manifold, and the second outlet is further connected to the main manifold.

24. The electronic device as claimed in claim 11, wherein the peripheral flow channel is not in direct communication with the heat exchange chamber.

25. The electronic device as described in claim 11 further includes a cabinet, wherein the motherboard module is configured to be mounted in the cabinet.

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