Power assembly

Abstract

The invention discloses a power assembly. The power assembly comprises a power device packaging module; and the radiator is provided with a cavity for accommodating a cooling working medium and a plurality of hollow radiating fins. Wherein the power device packaging module is connected with the radiator, a first capillary structure layer and a second capillary structure layer are arranged in the cavity, the first capillary structure layer is arranged on the surface of the power device packaging module, and the second capillary structure layer is arranged on the surface of the radiator; an evaporation area of the cooling working medium is formed on the surface of the power device packaging module, a condensation area of the cooling working medium is formed by the hollow heat dissipation fins, and the cooling working medium is condensed in the hollow heat dissipation fins and then flows back to the first capillary structure layer from the second capillary structure layer. The radiator used by the power assembly has the advantages of being light in weight, saving material cost and being large in heat dissipation area, heat can be evenly diffused to all the heat dissipation fins through evaporation of the cooling working medium, rapid heat dissipation is achieved through evaporation-cooling circulation of the cooling working medium, and the heat dissipation efficiency is remarkably improved.

Description

Technical Field

[0001] The present invention discloses a power component; more specifically, it discloses a power component with a capillary structure radiator. Background Art

[0002] Semiconductor power devices such as IGBT chips, MOSFET chips, etc. are widely used in various power electronic devices. When such power devices work, they will generate a large amount of heat. If the generated heat cannot be dissipated in time, it will seriously affect the operation of the power device and its surrounding electronic components. Therefore, the design of the heat dissipation structure is particularly important.

[0003] The traditional fin radiator usually includes a plurality of heat dissipation fins. The heat generated by the power device can diffuse through the heat dissipation fins to achieve the purpose of cooling. However, this type of fin radiator is generally formed by die-casting molds or machining metal block materials. It not only has a large weight and volume, but also has uneven heat dissipation effects. The temperature of the heat dissipation fins close to the power device will be significantly higher than that of the heat dissipation fins far from the power device, and the full effect of all heat dissipation fins cannot be fully utilized.

[0004] The heat pipe is another commonly used heat dissipation structure. The capillary structure provided inside the heat pipe can enable heat to quickly diffuse throughout the heat pipe and have a relatively uniform distribution. However, the problem with it is that the heat dissipation area is limited, and the overall heat dissipation efficiency still needs to be improved. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the main purpose of the present invention is to provide a power component with better heat dissipation effect and lightweight.

[0006] To achieve the above main purpose, the present invention discloses a power component, which includes:

[0007] A power device packaging module, which internally packages one or more power devices;

[0008] A radiator, which has a cavity for accommodating a cooling working fluid and a plurality of hollow heat dissipation fins;

[0009] The power device packaging module is connected to the radiator and seals the cavity. A first capillary structure layer and a second capillary structure layer are provided in the cavity. The first capillary structure layer is arranged on the surface of the power device packaging module, and the second capillary structure layer is arranged on the surface of the radiator;

[0010] The surface of the power device packaging module forms an evaporation area of the cooling working fluid, and the hollow heat dissipation fins form a condensation area of the cooling working fluid. After the cooling working fluid condenses in the hollow heat dissipation fins, it flows back from the second capillary structure layer to the first capillary structure layer.

[0011] According to a specific embodiment of the present invention, the radiator is provided with a prismatic frame body, the power device packaging module is arranged in the prismatic frame body, and a plurality of the hollow heat dissipation fins are arranged on at least one side wall of the prismatic frame body.

[0012] Further, the first capillary structure layer is provided on each of the four surfaces of the power device packaging module connected to the prismatic frame body, and the second capillary structure layer is provided on the four side walls of the prismatic frame body and the inner surfaces of the hollow heat dissipation fins.

[0013] According to a specific embodiment of the present invention, the power device packaging module is provided with a heat conduction substrate, the heat conduction substrate includes a core board, a first copper foil layer located on the first side surface of the core board, and a second copper foil layer located on the second side surface of the core board. The core board is a ceramic core board or an insulating core board embedded with ceramic blocks. The first copper foil layer is connected to the first capillary structure layer, and the second copper foil layer is connected to the power device.

[0014] Further, a plurality of the hollow heat dissipation fins are arranged on the side wall of the frame body of the radiator facing the heat conduction substrate. An interval part is arranged between the hollow heat dissipation fins. A plurality of support protrusions are arranged along the length direction of the interval part. The support protrusions pass through the first capillary structure layer and the second capillary structure layer and are connected to the heat conduction substrate.

[0015] Further, the first capillary structure layer has a hollow convex column sleeved outside the support protrusion, and the front end of the hollow convex column is in contact with the second capillary structure layer.

[0016] According to a specific embodiment of the present invention, the radiator is arranged on one side of the power device packaging module where the heat conduction substrate is provided, and the heat conduction substrate is connected to the radiator to seal the cavity.

[0017] According to a specific embodiment of the present invention, convex portions are formed by squeezing inward on two opposite side walls of each of the hollow heat dissipation fins, so that the second capillary structure layer forms abutting portions that abut against each other at the convex portions.

[0018] According to a specific embodiment of the present invention, the radiator is obtained by integrally forming a metal plate provided with the second capillary structure layer. The metal plate is a copper foil plate with a thickness of 0.1 mm to 1.0 mm.

[0019] According to a specific embodiment of the present invention, the first capillary structure layer is a first copper mesh with a thickness of 0.2 mm to 0.8 mm, and the second capillary structure layer is a second copper mesh with a thickness of 0.1 mm to 0.5 mm.

[0020] The technical solution of the present invention has the following beneficial effects:

[0021] (1) The radiator with hollow heat dissipation fins has a larger heat dissipation area, lighter weight, and significantly reduces the material consumption and cost of the radiator compared with the traditional fin radiator. Compared with the traditional flat-shaped isothermal radiator, it has a larger heat dissipation area.

[0022] (2) The surface of the power device packaging module is provided with a first capillary structure layer, and the inner surface of the hollow heat dissipation fin is provided with a second capillary structure layer. During the heat conduction process, an evaporation area is formed on the surface of the power device packaging module, and a condensation area is formed on the hollow heat dissipation fin. The heat inside the power device packaging module can be quickly diffused through the evaporation of the liquid cooling working medium, and the heat can be evenly conducted to all the heat dissipation fins quickly through the evaporation-cooling cycle of the cooling working medium, significantly improving the heat dissipation efficiency.

[0023] (3) Preferably, the heat-conducting substrate for installing the power device is in direct contact with the cooling working medium. Compared with the heat dissipation structures of traditional fin radiators and heat pipes that need to connect the power device through an intermediate heat-conducting medium / structure, it is beneficial to reduce the number of heat transfer interfaces and thermal resistance.

[0024] (4) Preferably, the radiator has a prismatic frame body, and the four surfaces where the power device packaging module is connected to the prismatic frame body can all be used as the evaporation area of the cooling working medium for heat dissipation, forming a three-dimensional heat dissipation channel, enabling the heat to be transferred to the radiator more quickly.

[0025] In order to more clearly illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Description of the Drawings

[0026] Figure 1 is the overall structure schematic diagram of Embodiment 1 of the present invention;

[0027] Figure 2 is the connection structure diagram of the radiator and the ceramic substrate in Embodiment 1 of the present invention;

[0028] Figure 3 is the exploded structure schematic diagram of the radiator and the ceramic substrate in Embodiment 1 of the present invention;

[0029] Figure 4 is the structure schematic diagram of the radiator in Embodiment 1 of the present invention;

[0030] Figure 5 is the structure schematic diagram of the second copper mesh in Embodiment 1 of the present invention;

[0031] Figure 6 is the front view of the radiator and the second copper mesh in Embodiment 1;

[0032] Figure 7 is Figure 6 the A-A sectional view of;

[0033] Figure 8 is Figure 6 the B-B sectional view of;

[0034] Figure 9 is the schematic structural view of the first copper mesh in Embodiment 1;

[0035] Figure 10 is the structural view of the power device package module removed in Embodiment 1 of the present invention;

[0036] Figure 11 is the schematic structural view of the heat dissipation component in Embodiment 2 of the present invention;

[0037] Figure 12 is the schematic structural view of the heat sink in Embodiment 2 of the present invention;

[0038] Figure 13 is the schematic structural view of the heat conduction substrate in another embodiment of the present invention. Specific Embodiments

[0039] In the following description, many specific details are set forth in conjunction with the embodiments to facilitate a full understanding of the present invention. However, it should be understood that the following embodiments and detailed description are for illustrative purposes only and do not limit the scope of protection of the present invention.

[0040] Embodiment 1

[0041] As Figures 1-4 shown, the power component of Embodiment 1 includes a power device package module 100 and a heat sink 20. The heat sink 20 has a plurality of hollow heat dissipation fins 22 and a cavity 24 for accommodating a cooling working medium. The power device package module 100 includes a heat conduction substrate 10, one or more power devices (not shown in the figure) disposed on the heat conduction substrate 10, and a package body 101 (such as a packaging resin) for packaging the power devices. The heat conduction substrate 10 is exposed from one side of the package body 101. The heat sink 20 is disposed on the side of the power device package module 100 where the heat conduction substrate 10 is provided, and the heat conduction substrate 10 is connected to the heat sink 20 to seal the cavity 24. Preferably, a negative pressure environment is formed in the cavity 24 to promote the evaporation-condensation cycle of the cooling working medium.

[0042] In the present invention, the connection between the heat sink 20 and the heat conduction substrate 10 can be achieved by welding connection or fixed connection with fasteners (such as screws or bolts), and the present invention does not limit this. The cooling working medium can be any one or more of water, ethanol, acetone, etc., and the present invention does not limit this.

[0043] In the present invention, the heat-conducting substrate 10 preferably adopts an AMB (active metal brazing) ceramic substrate, which can not only play an electrical insulation role but also has good heat-conducting effect. Specifically, the heat-conducting substrate 10 includes a first copper foil layer 12 on its first side surface, a second copper foil layer 13 on its second side surface, and a ceramic core board 11 disposed between the first copper foil layer 12 and the second copper foil layer 13. The first copper foil layer 12 is used to connect a first copper mesh 31 as an example of the first capillary structure layer, and the second copper foil layer 13 is used to connect a power device. In the present invention, the second copper foil layer 13 may form a conductive circuit or may not be provided with a conductive circuit, which can be specifically set according to needs, and the present invention does not limit this.

[0044] As Figure 4 shown, in Embodiment 1, the radiator 20 includes a generally plate-shaped frame body 21, a plurality of hollow heat dissipation fins 22, and a plurality of spacer portions 23. The frame body 21 is hermetically connected to the first copper foil layer 12 of the heat-conducting substrate 10. The spacer portions 23 and the hollow heat dissipation fins 23 are alternately arranged in the frame body 21. A recessed portion 241 is formed in the frame body 21, and the recessed portion 241 and the internal flow channel 242 of the hollow heat dissipation fin 22 constitute a cavity 24. The spacer portion 23 constitutes the bottom wall of the recessed portion 24, and the hollow heat dissipation fin 22 extends toward the side of the spacer portion 23 away from the frame body 21. Each of the hollow heat dissipation fins 23 is in a flat plate shape and includes two parallel side walls 221, and an internal flow channel 242 is formed between the two side walls 221.

[0045] Further, a second copper mesh 32 as an example of the second capillary structure layer is provided on the inner side surface of the hollow heat dissipation fin 22. Both ends 325 of the second copper mesh 32 are in contact with the first copper mesh 31 to form a continuous capillary structure, promoting the liquid cooling working medium to flow back from the second copper mesh 32 to the first copper mesh 31.

[0046] In the embodiment of the present invention, the thickness of the first copper mesh 31 as an example of the first capillary structure layer may be 0.2 mm to 0.8 mm, more specifically 0.3 mm to 0.5 mm; the thickness of the second copper mesh 32 as an example of the second capillary structure layer may be 0.1 mm to 0.5 mm, more specifically 0.1 mm to 0.3 mm. Preferably, the thickness of the first copper mesh 31 is greater than the thickness of the second copper mesh 32 to store / absorb more liquid cooling working medium and promote more rapid heat conduction in the heat-conducting substrate 10.

[0047] In other embodiments of the present invention, the first capillary structure layer and the second capillary structure layer may be a porous metal layer formed by sintered metal powder (such as copper powder), a capillary woven mesh formed by weaving fiber filaments or other metal wires (such as aluminum wires) other than copper wires, and / or capillary grooves machined on the inner wall of the cavity 24 (the surface of the first copper foil layer 12 and the inner surface of the radiator 20).

[0048] As shown Figures 5-8 in the figure, the second copper mesh 32 has a tortuous continuous structure adapted to the hollow heat dissipation fins 22, including a vertical wall 321 attached to the inner surface of the hollow heat dissipation fins 22 and a connecting portion 323 attached to the spacer portion 23. The vertical walls 321 are arranged in pairs, and each pair of vertical walls 321 includes a first vertical wall 321a and a second vertical wall 321b that are parallel to each other. The first vertical wall 321a and the second vertical wall 321b are respectively attached to the two side walls 221 of the hollow heat dissipation fins 22.

[0049] Preferably, one or more protruding portions 222 protruding inward are provided on the two opposite side walls 221 of each hollow heat dissipation fin 22. The protruding portions 222 can be obtained by locally extruding the radiator 20. After the protruding portions 222 are extruded and formed, corresponding abutting portions 322 protruding inward are formed on the first vertical wall 321a and the second vertical wall 321b of the second copper mesh 32, and the abutting portions 322 on the first vertical wall 321a and the second vertical wall 321b abut against each other. In this way, not only can the structural strength of the hollow heat dissipation fins 22 be enhanced, but also the connection reliability between the second copper mesh 32 and the hollow heat dissipation fins 22 can be improved. The protruding portions 222 are preferably strip-shaped structures extending along the height direction of the side wall 221, but are not limited thereto. For example, the protruding portions 222 are arranged in a dot matrix distribution on the side wall 221.

[0050] Furthermore, a plurality of support protrusions 231 are provided on the spacer portion 23 of the radiator 20 along its length direction. The support protrusions 231 can also be obtained by locally extruding the radiator 20. The support protrusions 231 are arranged to be connected to the heat conducting substrate 10, which not only helps to enhance the structural strength of the radiator 20 to better maintain the shape stability of the radiator 20, but also promotes the rapid conduction of the heat of the heat conducting substrate 10 to the radiator 20.

[0051] As shown Figure 5 in the figure, a through hole 324 for the support protrusion 231 to pass through is provided on the connecting portion 323 of the second copper mesh 32; as shown Figure 9 and 10 in the figure, a plurality of hollow protrusions 311 are provided on the first copper mesh 31. The hollow protrusions 311 are sleeved on the support protrusions 231, and the front ends of the hollow protrusions 311 are in contact with the second copper mesh 32 to increase the contact area between the two, so that the condensed liquid cooling working medium can flow back from the second copper mesh 32 to the first copper mesh 31 more quickly, accelerating the evaporation-cooling cycle of the cooling working medium.

[0052] When the heat generated by the power device enters the heat-conducting substrate 10, the first copper foil layer 12 on the inner surface of the heat-conducting substrate 10 in contact with the cooling working fluid forms an evaporation zone. The liquid cooling working fluid in the first copper mesh 31 will quickly absorb heat and form steam, taking away a large amount of thermal energy. Since the density of the steam working fluid is smaller than that of the liquid working fluid, under the action of the thermosiphon effect, the steam near the heat-conducting substrate 10 will quickly diffuse into the hollow heat-dissipating fins 22. When the steam contacts the relatively low-temperature heat-dissipating fins 22, the steam will quickly condense into a liquid and release thermal energy. The condensed liquid cooling working fluid flows back to the first copper mesh 31 under the capillary action of the second copper mesh 32, thus completing a cycle. With the help of this cycle of the cooling working fluid, heat can be evenly transferred to all the heat-dissipating fins 22, enabling them to effectively participate in heat dissipation.

[0053] In an embodiment of the present invention, the radiator 20 can be obtained by integrally forming a metal plate provided with the second copper mesh 32. Among them, the thickness of the metal plate can be 0.1 mm to 1.0 mm. The metal plate is preferably a copper foil plate, but is not limited thereto. For example, an aluminum foil plate can also be used.

[0054] In a specific embodiment, the radiator 20 and the second copper mesh 32 can be formed as follows: First, connect (such as bond or weld) the second copper mesh 32 to the surface of the metal plate; then, perform local extrusion forming on the metal plate to obtain the protruding part 222 and the supporting protrusion 231; then, bend the metal plate 20a and the second copper mesh 32 together to form the overall outer contour of the radiator 20; finally, seal the two ends of the hollow heat-dissipating fins 22 in the length direction, for example, heat-seal the two ends of the hollow heat-dissipating fins 22 together so that the two ends are sealed.

[0055] Further, as Figure 3 shown, the first copper foil layer 12 is provided with fluid channels 121 formed by etching. The fluid channels 121 communicate with the cavity 24, and the frame 21 of the radiator 20 is provided with through holes 211 communicating with the fluid channels 121. After completing the connection between the heat-conducting substrate 10 and the radiator 20, the cavity 24 can be evacuated and filled with the cooling working fluid through the through holes 211 and the fluid channels 121, and then the fluid channels 121 or the through holes 211 are sealed. For example, by heating the part of the frame 21 covering the fluid channels 121, the frame 21 is locally melted to seal the fluid channels 121.

[0056] Embodiment 2

[0057] Embodiment 2 is an improvement based on Embodiment 1. As Figure 11 and 12As shown, in Embodiment 2, the housing 21 of the radiator 20 forms a prismatic housing, and the power device packaging module 100 is disposed within the prismatic housing. Specifically, the prismatic housing 21 is provided with a first sidewall 21a, a second sidewall 21b, a third sidewall 21c, and a fourth sidewall 21d. The first sidewall 21a is connected to the heat-conducting substrate 10, and a plurality of hollow heat dissipation fins 22 are disposed on the first sidewall 21a. The second sidewall 21b is parallel to the first sidewall 21a, and its two ends parallel to the hollow heat dissipation fins 22 are respectively connected through the third sidewall 21c and the fourth sidewall 21d.

[0058] Depressions 241 are formed on the inner sides of the four sidewalls of the prismatic housing 21, and second copper meshes 32 as examples of the second capillary structure layer are provided on the inner surfaces of the four sidewalls of the prismatic housing 21 and the hollow heat dissipation fins 22. First copper meshes 31 as examples of the first capillary structure layer are provided on the four surfaces of the power device packaging module 100 connected to the prismatic housing 21. Compared with Embodiment 1 in which only the heat-conducting substrate 10 of the power device packaging module 100 serves as the evaporation area, in Embodiment 2, the four surfaces of the power device packaging module 100 connected to the prismatic housing 21 can all serve as evaporation areas for heat dissipation, forming a three-dimensional heat dissipation structure, enabling heat to be transferred to the hollow heat dissipation fins 22 of the radiator 20 more rapidly through the evaporation-cooling cycle of the cooling working fluid; meanwhile, the four sidewalls of the prismatic housing 21 can also participate in heat dissipation.

[0059] Further, a sealable through-hole 211 is provided on the second sidewall 21b of the prismatic housing 21, and the through-hole 211 is connected to the depression 241 provided on the inner wall of the prismatic housing 21, so as to facilitate evacuating the cavity 24 through the through-hole 211 and injecting the cooling working fluid. The through-hole 211 can also be provided on other sidewalls of the prismatic housing 21, and the present invention places no limitation thereon.

[0060] For other descriptions of Embodiment 2, reference can be made to Embodiment 1, which will not be elaborated herein.

[0061] In other embodiments of the present invention, as Figure 13 shown, an insulating core board 14 such as an FR-4 core board can be used for electrical insulation between the first copper foil layer 12 and the second copper foil layer 13 of the heat-conducting substrate 10. A ceramic block 15 for heat conduction is embedded in the insulating core board 14. Wherein, copper-clad layers 16 can be provided on two opposite surfaces of the ceramic block 15, and the ceramic block 15 is connected to the first copper foil layer 12 and the second copper foil layer 13 through the corresponding copper-clad layers 16. As a variation, the ceramic block 15 can also be directly connected to the first copper foil layer 12 and the second copper foil layer 13. Further, the insulating core board 14 can include one or more FR-4 core boards, and inner conductive circuits can be provided in the insulating core board 14.

[0062] Although the present invention has been depicted through embodiments above, the above embodiments are only used to exemplarily describe the feasible embodiments of the present invention, rather than to limit the protection scope of the present invention. Any equivalent substitution or change made by those skilled in the art in accordance with the present invention shall also be covered by the protection scope defined by the claims of the present invention.

Claims

1. A power component, characterized in that Comprising: A power device packaging module internally encapsulating one or more power devices; A heat sink having a cavity for accommodating a cooling working fluid and a plurality of hollow heat dissipation fins; The power device packaging module is connected to the heat sink and seals the cavity. A first capillary structure layer and a second capillary structure layer are provided in the cavity. The first capillary structure layer is disposed on the surface of the power device packaging module, and the second capillary structure layer is disposed on the surface of the heat sink; An evaporation area of the cooling working fluid is formed on the surface of the power device packaging module, and a condensation area of the cooling working fluid is formed by the hollow heat dissipation fins. After the cooling working fluid condenses in the hollow heat dissipation fins, it flows back from the second capillary structure layer to the first capillary structure layer.

2. The power component according to claim 1, characterized in that: The heat sink is provided with a prismatic frame body, and the power device packaging module is disposed in the prismatic frame body. A plurality of the hollow heat dissipation fins are provided on at least one side wall of the prismatic frame body.

3. The power component according to claim 2, wherein: The first capillary structure layer is provided on four surfaces of the power device packaging module connecting to the prismatic frame body, and the second capillary structure layer is provided on four side walls of the prismatic frame body and the inner surfaces of the hollow heat dissipation fins.

4. The power component according to claim 1, characterized in that: The power device packaging module is provided with a heat conducting substrate. The heat conducting substrate includes a core board, a first copper foil layer on the first side surface of the core board, and a second copper foil layer on the second side surface of the core board. The core board is a ceramic core board or an insulating core board embedded with ceramic blocks. The first copper foil layer is connected to the first capillary structure layer, and the second copper foil layer is connected to the power device.

5. The power component according to claim 4, characterized in that: A plurality of the hollow heat dissipation fins are provided on the side wall of the frame body of the heat sink facing the heat conducting substrate. There are spacing portions between the hollow heat dissipation fins. A plurality of support protrusions are provided along the length direction of the spacing portions. The support protrusions pass through the first capillary structure layer and the second capillary structure layer and are connected to the heat conducting substrate.

6. The power component according to claim 5, wherein: The first capillary structure layer has a hollow convex column sleeved outside the support protrusion, and the front end of the hollow convex column is in contact with the second capillary structure layer.

7. The power component according to claim 4, characterized in that: The heat sink is disposed on one side of the power device packaging module where the heat conducting substrate is provided, and the heat conducting substrate is connected to the heat sink to seal the cavity.

8. The power component according to claim 1, characterized in that: Protrusions are formed by inward extrusion on two opposite side walls of each of the hollow heat dissipation fins, so that abutting portions that abut against each other are formed at the protrusions of the second capillary structure layer.

9. The power component according to claim 1, wherein: The heat sink is obtained by integrally forming a metal plate provided with the second capillary structure layer. The metal plate is a copper foil plate with a thickness of 0.1 mm to 1.0 mm.

10. The power component according to claim 1, characterized in that: The first capillary structure layer is a first copper mesh with a thickness of 0.2 mm to 0.8 mm, and the second capillary structure layer is a second copper mesh with a thickness of 0.1 mm to 0.5 mm.

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