CN115666100A - Heat radiation structure and power module assembly - Google Patents

Abstract

The application provides a heat radiation structure and power module assembly, heat radiation structure includes first heat conductor and second heat conductor. The first heat conductor comprises a body, and an input port and an output port which protrude out of the body, wherein the body is provided with a first groove and a second groove which are oppositely arranged. The first groove is communicated with the input port and the output port, the input port is used for inflow of cooling liquid, and the output port is used for outflow of the cooling liquid. The second groove is internally provided with a first fin group. The second heat conductor comprises a heat conduction substrate and a second fin group connected with the heat conduction substrate, the second fin group is contained in the first groove, and the second heat conductor is made of boron arsenide. This application heat radiation structure and power module subassembly have the first heat-conducting body and the second heat-conducting body of liquid cooling effect and air-cooled effect through the setting, have found the multimedium radiating passage of air-cooled and liquid cooling to can promote the radiating effect by a wide margin.

Description

Heat radiation structure and power module assembly

Technical Field

The present application relates to the field of semiconductor heat dissipation technologies, and in particular, to a heat dissipation structure and a power module assembly including the same.

Background

The power module is an electronic device which internally comprises a chip and a corresponding circuit and is externally packaged by plastic packaging materials. For a conventional power module (e.g., a silicon power module), an existing heat dissipation structure generally includes a heat dissipation plate made of pure copper material and a heat sink for accommodating a cooling liquid, and adopts a single-channel heat dissipation form of air cooling or liquid cooling. However, as semiconductor technology advances, more powerful power modules (e.g., silicon carbide power modules) are increasingly used, and the heat dissipation capability of the heat dissipation structure is also more challenging.

Practical use and test results show that the heat dissipation performance of the conventional single-channel heat dissipation structure is insufficient, the heat dissipation requirement of a high-power (silicon carbide) power module is difficult to meet, and the performance of the high-power module is limited.

Disclosure of Invention

In view of this, the present application provides a heat dissipation structure and a power module assembly capable of improving heat dissipation effect.

An embodiment of the present application provides a heat dissipation structure, which includes a first heat conductor and a second heat conductor. The first heat conductor comprises a body, and an input port and an output port which protrude from the body, and the body is provided with a first groove and a second groove which are oppositely arranged. The first groove is communicated with the input port and the output port, the input port is used for inflow of cooling liquid, and the output port is used for outflow of the cooling liquid. And a first fin group is arranged in the second groove. The second heat conductor comprises a heat conduction substrate and a second fin group connected with the heat conduction substrate, the second fin group is contained in the first groove, and the second heat conductor is made of boron arsenide.

In one embodiment, the second fin group includes a plurality of second heat dissipation fins arranged at intervals. The arrangement direction of the plurality of second radiating fins is perpendicular to the direction from the input port to the output port, the extension direction of each second radiating fin is consistent with the direction from the input port to the output port, and the orthographic projection of each second radiating fin is wavy.

In one embodiment, the number of the input ports is plural, and the plural input ports are arranged along the arrangement direction of the plural second heat dissipation fins.

In one embodiment, the first fin group includes a plurality of first heat dissipation fins arranged at intervals. The arrangement direction of the first radiating fins is consistent with the direction from the input port to the output port, and the extension direction of each first radiating fin is perpendicular to the direction from the input port to the output port.

In one embodiment, the input port is located lower than the bottom wall of the first groove, and the output port is located lower than the bottom wall of the first groove in the thickness direction of the first heat conductor.

In one embodiment, the body is further provided with a first communicating cavity for communicating the input port with the first groove, and a second communicating cavity for communicating the output port with the first groove.

An embodiment of the present application provides a power module assembly, which includes the heat dissipation structure and the power module as described above, where the power module is disposed on a surface of the second heat conductor, which is away from the first heat conductor.

In one embodiment, the power module assembly further comprises a third thermal conductor disposed between the power module and the second thermal conductor.

In one embodiment, the third thermal conductor includes at least one of a thermal silicone grease, a liquid metal, or a thermal gel.

In one embodiment, the number of the power modules is multiple, and the number of the input ports is multiple. The number of the input ports is consistent with that of the power modules, and the arrangement direction of the power modules is consistent with that of the input ports.

This application heat radiation structure and power module subassembly have the first heat conductor and the second heat conductor of liquid cooling effect and air-cooled effect through the setting, have constructed the multimedium radiating passage of air-cooled and liquid cooling to can promote the radiating effect by a wide margin (promote 20% ~ 40%). And the second heat conductor is made of a high-heat-conduction boron arsenide material, so that the heat dissipation performance can be effectively improved. In addition, the power module cooling system is also provided with a plurality of input ports corresponding to the number and the positions of the power modules, so that the balanced cooling effect of each power module can be realized, and the problems of uneven heat dissipation effect, large temperature difference and low overall heat dissipation performance of a single input port are solved, thereby being beneficial to the development of the power modules in the high-power direction, and being capable of improving the reliability and the service life of the power modules.

Drawings

Fig. 1 is a schematic structural diagram of a heat dissipation structure according to an embodiment of the present application.

Fig. 2 is an exploded view of the heat dissipation structure shown in fig. 1.

Fig. 3 is a schematic structural diagram of a first heat conductor of the heat dissipation structure shown in fig. 1 according to an embodiment.

Fig. 4 is a top view of the first thermal conductor of fig. 3.

Fig. 5 is a side view of the first thermal conductor of fig. 3.

FIG. 6 is a schematic cross-sectional view of the first thermal conductor of FIG. 3 taken along line VI-VI.

Fig. 7 is a schematic structural diagram of a second heat conductor of the heat dissipation structure shown in fig. 1 according to an embodiment.

Fig. 8 is a top view of the second thermal conductor of fig. 7.

Fig. 9 is a schematic structural diagram of a power module assembly according to an embodiment of the present application.

Fig. 10 is an exploded view of the power module assembly shown in fig. 9.

Description of the main elements

Heat dissipation structure 100

First heat conductor 10

A second heat conductor 20

Body 11

Input port 12

Output port 13

Heat conductive substrate 21

Second fin group 22

First surface 101

Second surface 102

First side 103

Second side 104

Third side 105

Fourth side 106

First groove 110

Second groove 120

First fin group 111

First heat dissipating fin 112

First communicating chamber 113

The second communicating chamber 114

Second heat dissipating fin 220

Power module assembly 1000

Power module 200

Third heat conductor 30

The following detailed description will further describe embodiments of the present application in conjunction with the above-described figures.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this application belong. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the present application.

It should be noted that all directional indicators (such as up, down, left, right, front, back \8230;) in the embodiments of the present application are only used to explain the relative positional relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

It will be understood that when a layer is referred to as being "on" another layer, it can be directly on the other layer or intervening layers may be present. In contrast, when a layer is referred to as being "directly on" another layer, there are no intervening layers present.

In addition, in the description of the present application, "a plurality" means at least two, e.g., two, three, etc., unless explicitly specified otherwise.

Embodiments of the present application are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate constructions) of the present application. Thus, variations in the shapes of the illustrations as a result of manufacturing processes and/or tolerances are to be expected. Accordingly, embodiments of the present application should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. The regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of the device and are not intended to limit the scope of the application.

Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following embodiments, features of the embodiments may be combined with each other without conflict.

Referring to fig. 1 and 2, in one aspect, a heat dissipation structure 100 is provided, which includes a first heat conductor 10 and a second heat conductor 20.

Referring to fig. 3 to 6, the first heat conductor 10 includes a body 11. The body 11 is substantially a rectangular parallelepiped structure, and includes a first surface 101, a second surface 102, a first side 103, a second side 104, a third side 105, and a fourth side 106, which are disposed opposite to each other, the first side 103, the second side 104, the third side 105, and the fourth side 106 are sequentially disposed along a periphery of the first surface 101 and connected to the second surface 102, the first side 103 is disposed opposite to the third side 105, and the second side 104 is disposed opposite to the fourth side 106.

The body 11 is provided with a first groove 110 and a second groove 120 which are oppositely arranged. The first groove 110 is formed by the first surface 101 of the body 11 partially recessed toward the second surface 102. The second groove 120 is formed by the second surface 102 of the body 11 partially recessed toward the first surface 101 and extends through the fourth side 106 and the second side 104. The second groove 120 is provided with a first fin group 111, the first fin group 111 extends from the fourth side 106 to the second side 104, and the surface of the first fin group 111 facing away from the bottom wall of the second groove 120 is flush with the second surface 102 or slightly lower than the second surface 102. The first fin group 111 and the body 11 may be integrally formed or separately formed. In the present embodiment, the first fin group 111 is integrally formed with the main body 11.

The first heat conductor 10 further includes an input port 12 protruding from the first side surface 103 of the body 11 and an output port 13 protruding from the third side surface 105 of the body 11, and the first groove 110 is communicated with the input port 12 and the output port 13. The input port 12 is used for the inflow of a cooling fluid (not shown), and then the cooling fluid enters the first groove 110 and flows out through the output port 13, so as to construct a liquid cooling channel to take away heat. The number of the input ports 12 may be plural, and the number of the output ports 13 may be one. The shape of the input port 12 or the output port 13 may be regular or irregular such as cylindrical, square, etc., and the application is not limited thereto. In this embodiment, the number of the input ports is three. The cooling fluid may be, but is not limited to, one or more of water, ethanol, or glycol.

Referring to fig. 7 and 8, the second heat conductor 20 includes a heat conducting substrate 21 and a second fin group 22 connected to the heat conducting substrate 21, and the heat conducting substrate 21 and the second fin group 22 may be integrally formed. The second fin group 22 is accommodated in the first groove 110 (see fig. 6), and the height of the second fin group 22 is consistent with the depth of the first groove 110. The heat conductive substrate 21 covers an opening of the first recess 110.

The material of the second heat conductor 20 includes Boron Arsenide (BAs), that is, the heat conducting substrate 21 and the second fin group 22 may be made of a boron arsenide material. The thermal conductivity of the boron arsenide is 1300W/mK, which is more than three times of that of pure copper (400W/mK) in the traditional heat conduction material. The second heat conductor 20 is made of a boron arsenide material, so that the heat dissipation capability of the heat dissipation structure 100 can be greatly improved.

As shown in fig. 6, in some embodiments, the first fin group 111 includes a plurality of first heat dissipating fins 112 arranged at intervals. A plurality of first heat dissipation fins 112 are arranged along a direction from the input port 12 to the output port 13, and each of the first heat dissipation fins 112 extends in a direction substantially perpendicular to the direction from the input port 12 to the output port 13 (i.e., in a direction from the fourth side 106 toward the second side 104 or substantially parallel thereto).

The first fin set 111 may be made of a metal material, such as but not limited to copper, aluminum or an alloy material. In other embodiments, the first heat sink fins 112 may also be made of other materials, such as graphite or composite materials; alternatively, the first heat dissipation fin 112 may also include a core layer (not shown) and a coating layer (not shown) coated outside the core layer, one of the core layer and the coating layer is made of a metal material, and the other is made of graphene. The first fin group 111 may dissipate heat through natural flow of air, or may perform forced air cooling through an external air duct (not shown) to further improve the heat dissipation effect.

As shown in fig. 6, in some embodiments, along the thickness (height) direction of the first heat conductor 10, the input port 12 is located lower than the bottom wall of the first recess 110, and the output port 13 is located lower than the bottom wall of the first recess 110. Specifically, when the shape of the input port 12 or the output port 13 is cylindrical, the highest point of the input port 12 or the output port 13 is lower than the bottom wall of the first groove 110; when the shape of the input port 12 or the output port 13 is square, the surface of the input port 12 or the output port 13 close to the first surface 101 is lower than the bottom wall of the first groove 110; when the shape of the input port 12 or the output port 13 is irregular, the highest point of the input port 12 or the output port 13 is lower than the bottom wall of the first groove 110. That is, the input port 12 and the output port 13 are inclined to the first groove 110, and are not arranged in parallel on the same horizontal line. Thus, the cooling liquid can have better contact effect with the second fin group 22 (see fig. 7) of the second heat conductor 20 after being input into the first groove 110, so that the heat dissipation performance of the heat dissipation structure 100 can be improved.

Further, as shown in fig. 6, the body 11 is further provided with a first communicating chamber 113 for communicating the input port 12 with the first groove 110, and a second communicating chamber 114 for communicating the output port 13 with the first groove 110. A certain angle is formed between the bottom wall of the first groove 110 and each of the first communicating cavity 113 and the second communicating cavity 114, and in this embodiment, each of the first communicating cavity 113 and the second communicating cavity 114 is obliquely and downwardly disposed to communicate the first groove 110 with the input port 12 or the output port 13.

As shown in fig. 7, in some embodiments, the second fin group 22 includes a plurality of second heat dissipation fins 220 arranged at intervals, and the arrangement direction of the plurality of second heat dissipation fins 220 is substantially perpendicular to the direction from the input port 12 to the output port 13 (see fig. 4). The extending direction of each second heat dissipation fin 220 is consistent with (approximately parallel to) the direction from the input port 12 to the output port 13, so that the cooling liquid can smoothly flow along the extending direction of the second heat dissipation fins 220, and the heat dissipation efficiency is improved. The orthographic projection of each second heat dissipation fin 220 on the heat conduction substrate 21 is a wave shape, and it can be understood that the wave shape can be regarded as formed by connecting a plurality of S-shaped curves. Compared with the conventional linear fins, the wavy second heat dissipation fins 220 have a larger effective contact area with the cooling liquid (which can be increased by about 30%); compared with the cylindrical fins, the second heat dissipation fins 220 are subjected to smaller pressure and smaller loss when the cooling liquid flows through.

As shown in fig. 2 and 7, in some embodiments, the input port 12 is provided in a plurality, and a plurality of the input ports 12 are arranged along the arrangement direction of the plurality of second heat dissipation fins 220.

Referring to fig. 9 and fig. 10, in another aspect, a power module assembly 1000 is further provided, which includes the heat dissipation structure 100 and the power module 200, where the power module 200 is disposed on a surface of the second heat conductor 20 facing away from the first heat conductor 10.

In some embodiments, as shown in fig. 9 and 10, the power module assembly 1000 further comprises a third thermal conductor 30, the third thermal conductor 30 being disposed between the power module 200 and the second thermal conductor 20. The thickness of the third thermal conductor 30 is small, which can be used to fill the small gap between the power module 200 and the second thermal conductor 20, and most of the surface of the power module 200 close to the third thermal conductor 30 is in contact with the surface of the second thermal conductor 20.

Further, the material of the third thermal conductor 30 may be, but not limited to, at least one of thermal grease, liquid metal (gallium synthetic metal, etc.), or thermal gel.

The third heat conductor 30 has good heat dissipation and heat conduction performance, and is beneficial to conducting heat generated by the power module 200 to the second heat conductor 20 and the first heat conductor 10. In addition, compare in the traditional way of welding power module 200 on the heat-conducting plate with the tin cream, this application directly sets up power module 200 on the surface of second heat-conducting body 20, and the clearance between is filled with third heat-conducting body 30, has avoided the radiating adverse effect of low heat-conducting tin cream to power module 200.

As shown in fig. 9 and 10, in some embodiments, the number of the power modules 200 is plural. The number of the input ports 12 is consistent with the number of the power modules 200, and is also multiple. The arrangement direction of the plurality of power modules 200 is the same as the arrangement direction of the plurality of input ports 12, and the position of each input port 12 approximately corresponds to the position of one power module 200. Compare in the design of single input port, this application is through setting up a plurality of input ports 12 that all correspond with power module 200's quantity and position, and the coolant liquid can flow in first recess 110 of first heat conductor 10 through each input port 12, and then can realize the balanced cooling effect to each power module 200, has improved the problem that single input port radiating effect is uneven, the difference in temperature is great and overall heat dispersion is lower.

The power module 200 may include a chip and corresponding circuits, a package casing, and the like, and the type of the power module 200 is not limited in this application. Preferably, the chip is a silicon carbide chip or the like having a large heat generation amount and a high heat dissipation requirement.

This application heat radiation structure 100 and power module subassembly 1000 have constructed the multimedium heat dissipation channel of forced air cooling and liquid cooling through setting up first heat conductor 10 and the second heat conductor 20 that have liquid cooling effect and forced air cooling effect to can promote the radiating effect by a wide margin (promote 20% ~ 40%). Moreover, the second heat conductor 20 is made of a high thermal conductivity boron arsenide material, which can effectively improve the heat dissipation performance. In addition, the plurality of input ports 12 corresponding to the number and positions of the power modules 200 are further arranged, so that a balanced cooling effect of each power module 200 can be realized, and the problems of uneven heat dissipation effect, large temperature difference and low overall heat dissipation performance of a single input port are solved, so that the power module 200 can be favorably developed in the high-power direction, and the reliability and the service life of the power module 200 can be improved.

The above description is a few specific embodiments of the present application, but in practical applications, the present application is not limited to these embodiments. Other modifications and changes made by those skilled in the art based on the technical idea of the present application should fall within the scope of the present application.

Claims (10)

1. A heat dissipation structure, comprising:

the first heat conductor comprises a body, and an input port and an output port which protrude out of the body, the body is provided with a first groove and a second groove which are arranged oppositely, the first groove is communicated with the input port and the output port, the input port is used for inflow of cooling liquid, the output port is used for outflow of the cooling liquid, and a first fin group is arranged in the second groove; and

the second heat conductor comprises a heat conduction substrate and a second fin group connected with the heat conduction substrate, the second fin group is contained in the first groove, and the second heat conductor is made of boron arsenide.

2. The heat dissipation structure of claim 1, wherein the second fin group comprises a plurality of second heat dissipation fins arranged at intervals, the arrangement direction of the plurality of second heat dissipation fins is perpendicular to the direction from the input port to the output port, the extension direction of each second heat dissipation fin is the same as the direction from the input port to the output port, and the orthographic projection of each second heat dissipation fin is in a wave shape.

3. The heat dissipating structure of claim 2, wherein the number of the input ports is plural, and a plurality of the input ports are arranged along the arrangement direction of the plurality of second heat dissipating fins.

4. The heat dissipation structure of claim 1, wherein the first fin group comprises a plurality of first heat dissipation fins arranged at intervals, the arrangement direction of the plurality of first heat dissipation fins is consistent with the direction from the input port to the output port, and the extension direction of each first heat dissipation fin is perpendicular to the direction from the input port to the output port.

5. The heat dissipation structure of claim 1, wherein the input port is positioned lower than the bottom wall of the first recess and the output port is positioned lower than the bottom wall of the first recess in a thickness direction of the first heat conductor.

6. The heat dissipation structure of claim 1, wherein the body is further provided with a first communication chamber for communicating the input port with the first groove, and a second communication chamber for communicating the output port with the first groove.

7. A power module assembly, comprising the heat dissipation structure as recited in any one of claims 1 to 6 and a power module, wherein the power module is disposed on a surface of the second heat conductor facing away from the first heat conductor.

8. The power module assembly of claim 7, further comprising a third thermal conductor disposed between the power module and the second thermal conductor.

9. The power module assembly of claim 8, wherein the material of the third thermal conductor comprises at least one of a thermally conductive silicone grease, a liquid metal, or a thermally conductive gel.

10. The power module assembly of claim 7, wherein the number of the power modules is plural, the number of the input ports is identical to the number of the power modules, and an arrangement direction of the plurality of power modules is identical to an arrangement direction of the plurality of input ports.

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