A power module

Abstract

The present invention provides a power module, which includes a power device, a ceramic substrate, a heat sink and power terminals. The heat sink includes a heat dissipation substrate and a heat dissipation component. The heat dissipation substrate includes a first surface and a second surface which are oppositely arranged. The ceramic substrate is disposed on the first surface of the heat dissipation substrate, and the heat dissipation component is disposed on the second surface of the heat dissipation substrate; the power device is disposed on the ceramic substrate; the power terminals are located at the edge positions of the ceramic substrate. One end of the power terminals is connected to the ceramic substrate, and the power terminals are also thermally connected to the first surface of the heat dissipation substrate through an insulating and thermally conductive material structure, adding a low-thermal-resistance thermal conduction path from the power terminals to the heat sink through the insulating and thermally conductive material structure, realizing efficient cooling of the power terminals at a lower cost, preventing the risk of thermal failure of the power terminals, and at the same time improving the integration degree of the power module.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation, and particularly to a power module. Background Art

[0002] In existing power modules, large current conduction is generally achieved between power terminals (usually copper terminals) and the system. Since the current-carrying cross-sectional area of the power terminals is generally small, the conduction loss of the power terminals is large. Moreover, due to limitations such as the layout of power devices, the power terminals are generally arranged at the peripheral edge positions of the power module, which is in the secondary heat dissipation area. Therefore, the thermal resistance of the heat conduction path from the power terminals to the radiator is large, the temperature of the terminals is relatively high, and there is a risk of thermal failure of terminal soldering.

[0003] To solve the problem of excessive temperature of the power terminals, the commonly adopted solution is to thermally conduct the terminals to the equipment housing through an insulating and thermally conductive material on the system side to achieve shell attachment heat dissipation. However, this solution requires secondary assembly of the module, which affects the integration of the module and the assembly of the system. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a power module, including a power device, a ceramic substrate, a radiator, and a power terminal. The radiator includes a heat dissipation substrate and a heat dissipation component. The heat dissipation substrate includes a first surface and a second surface arranged opposite to each other. The ceramic substrate is arranged on the first surface of the heat dissipation substrate, and the heat dissipation component is arranged on the second surface of the heat dissipation substrate; the power device is arranged on the ceramic substrate; the power terminal is located at the edge position of the ceramic substrate, one end of the power terminal is connected to the ceramic substrate, and the power terminal is also thermally conductively connected to the first surface of the heat dissipation substrate through an insulating and thermally conductive material structure.

[0005] Preferably, the first surface of the heat dissipation substrate is provided with a first convex structure, and the first convex structure is thermally conductively connected to the power terminal through the insulating and thermally conductive material structure.

[0006] Preferably, the first convex structure is integrally formed with the heat dissipation substrate, and the material of the first convex structure is the same as that of the heat dissipation substrate.

[0007] Preferably, a first groove is provided on the surface of the first convex structure facing the power terminal, a second convex structure adapted to the first groove is provided on the power terminal, and there is a gap between the second convex structure and the first groove, and the gap is filled with the insulating and thermally conductive material structure.

[0008] Preferably, an insulating layer is further provided on the outer periphery of the first convex structure.

[0009] Preferably, the power terminal is provided with a concave section bent towards the heat dissipation substrate, and the concave section is thermally connected to the heat dissipation substrate through the insulating and heat-conducting material structure.

[0010] Preferably, the heat dissipation substrate completely envelopes the projected area of the ceramic substrate.

[0011] Preferably, the heat conduction coefficient of the insulating and heat-conducting material structure is greater than 2 W / m·K.

[0012] Preferably, the insulating and heat-conducting material structure is a polymer structure.

[0013] Preferably, the insulating and heat-conducting material structure is a ceramic structure.

[0014] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0015] The present invention provides a power module. The power terminal is located at the edge position of the ceramic substrate. One end of the power terminal is connected to the ceramic substrate, and the power terminal is also thermally connected to the first surface of the heat dissipation substrate through an insulating and heat-conducting material structure, adding a low thermal resistance heat conduction path from the power terminal to the radiator through the insulating and heat-conducting material structure, realizing efficient cooling of the power terminal at a lower cost, preventing the risk of thermal failure of the power terminal, and improving the integration degree of the power module at the same time. Description of the Drawings

[0016] Figure 1 is a three-dimensional structure schematic diagram of a power module provided by an embodiment of the present invention;

[0017] Figure 2 is a three-dimensional structure schematic diagram of the other side of a power module provided by an embodiment of the present invention;

[0018] Figure 3 is a side view of a power module provided by an embodiment of the present invention;

[0019] Figure 4 is Figure 3 the enlarged view of part A in

[0020] Figure 5 is a connection structure schematic diagram of a power terminal and a heat dissipation substrate provided by Embodiment 2 of the present invention;

[0021] Figure 6 is a connection structure schematic diagram of a power terminal and a heat dissipation substrate provided by Embodiment 3 of the present invention Figure 1 ;

[0022] Figure 7 is a connection structure schematic diagram of a power terminal and a heat dissipation substrate provided by Embodiment 3 of the present invention Figure 2 . Detailed Embodiments

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order different from those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices. The terms "on" and "above" and any variations thereof are intended to describe a positional relationship and do not represent a direct contact relationship between the described objects.

[0025] Please refer to Figures 1 to 4 , the present invention provides a power module, including a power device 2, a ceramic substrate 3, a heat sink 4 and a power terminal 1. The heat sink 4 includes a heat dissipation substrate 401 and a heat dissipation component 402. The heat dissipation substrate 401 includes a first surface and a second surface arranged oppositely. The ceramic substrate 3 is disposed on the first surface of the heat dissipation substrate 401, and the heat dissipation component 402 is disposed on the second surface of the heat dissipation substrate 401; the power device 2 is disposed on the ceramic substrate 3.

[0026] The present invention does not limit the specific structure and quantity of the ceramic substrate 3. At the same time, it does not specifically limit how many power devices 2 can be disposed on the ceramic substrate 3, which can be set according to actual usage requirements.

[0027] As an embodiment, the ceramic substrate 3 includes a top copper layer 301, a ceramic layer 302, and a bottom copper layer 303 which are sequentially arranged. The power device 2 is fixed on the top copper layer 301 through a thermally and electrically conductive interface material 7 such as sintered silver or solder. The bottom copper layer 303 is fixed on the first surface of the heat dissipation substrate 401 through a thermally conductive interface material 8 such as solder, thermal grease or other materials. To prevent incomplete diffusion of the heat source (power device 2) resulting in local hot spots, thereby affecting the heat exchange performance of the radiator 4, in this embodiment, it is preferred that the first surface of the heat dissipation substrate 401 completely envelopes the projected area of the ceramic substrate 3, that is, the area of the heat dissipation substrate 401 is larger than the area of the ceramic substrate 3, with the aim of completely enclosing the ceramic substrate 3.

[0028] The bottom copper layer 303 of the ceramic substrate 3 is fixed on the radiator 4 through solder, thermal grease or other materials to achieve mechanical and thermally conductive connection with the radiator 4.

[0029] The second surface of the heat dissipation substrate 401 is the surface facing away from the ceramic substrate 3, and a heat dissipation component 402 is provided on this surface. The specific structure of the heat dissipation component 402 is not limited in the present invention and can be set according to actual usage requirements. As an embodiment, the heat dissipation component 402 includes several cylinders, elliptical cylinders, retaining walls or other heat dissipation columns that can increase the surface area.

[0030] The power terminal 1 is located at the edge position of the ceramic substrate 3. One end of the power terminal 1 is connected to the ceramic substrate 3, and the power terminal 1 is also thermally conductively connected to the first surface of the heat dissipation substrate 401 through an insulating thermally conductive material structure 5, adding a low thermal resistance heat conduction path from the power terminal 1 to the radiator 4 through the insulating thermally conductive material structure 5, achieving efficient cooling of the power terminal 1 at a lower cost, preventing the risk of thermal failure of the power terminal 1, and at the same time improving the integration degree of the power module.

[0031] In the present invention, the power terminal 1 and the heat dissipation substrate 401 can be directly or indirectly connected through the insulating thermally conductive material structure 5. The following lists several specific embodiments for detailed description.

[0032] Embodiment 1

[0033] Please refer to Figure 3, in this embodiment, the power terminal 1 is located at the edge position of the ceramic substrate 3, and one end of the power terminal 1 is electrically connected to the ceramic substrate 3 by ultrasonic welding or other means, and the other end of the power terminal 1 extends out of the ceramic substrate 3. Since the distance between the power terminal 1 and the first surface of the heat dissipation substrate 401 is relatively large, therefore, at the projection of the power terminal 1 on the first surface of the heat dissipation substrate 401, a first convex structure 6 with a certain height is provided on the first surface of the heat dissipation substrate 401. The first convex structure 6 is lower than the vertical height from the power terminal 1 to the first surface of the heat dissipation substrate 401. An insulating and heat-conducting material structure 5 with a certain thickness is provided on the first convex structure 6, and the first convex structure 6 is thermally connected to the power terminal 1 through the insulating and heat-conducting material structure 5.

[0034] The first convex structure 6 can be a structure integral with the heat dissipation substrate 401, then the first convex structure 6 can be made of the same material as the heat dissipation substrate 401. The first convex structure 6 can also be a structure integral with the insulating and heat-conducting material structure, then the first convex structure 6 can be made of the same material as the insulating and heat-conducting material structure 5, and the first convex structure 6 is thermally connected to the heat dissipation substrate 401 through the heat-conducting material. To obtain a better heat-conducting effect, in this embodiment, it is preferred that the first convex structure 6 is integrally formed with the heat dissipation substrate 401, then the first convex structure 6 is preferably made of the same material as the heat dissipation substrate 401. To reduce costs and the complexity of assembly, in this embodiment, it is preferred that the first convex structure 6 is integrally formed with the heat dissipation substrate 401 by forging or other means.

[0035] The insulating and heat-conducting material structure 5 has a certain thickness. Preferably, the thermal conductivity coefficient of the insulating and heat-conducting material structure 5 is greater than 2W / m·K, and the insulating and heat-conducting material structure 5 has a certain compressibility, such as a compression amount of 10%-50%, to absorb tolerances.

[0036] The insulating and heat-conducting material structure 5 is in contact with the power terminal 1. In this embodiment, no specific limitation is imposed on the material of the insulating and heat-conducting material structure 5. For example, it can be a polymer, such as a thermal gel, etc., or it can also be a ceramic. The ceramic and the power terminal 1 can be connected by active brazing or other means.

[0037] To meet the creepage distance safety requirements, an insulating layer, such as a polymer insulating layer, can be provided on the outer periphery of the first convex structure 6. Together with the insulating and heat-conducting material structure 5, it forms the outer insulation of the first convex structure 6, which can reduce the working temperature of the power terminal 1 while reducing the short-circuit risk between the power terminal 1 and the radiator 4.

[0038] In this embodiment, by adding a heat-conducting path between the heat dissipation substrate 401 and the power terminal 1, the working temperature of the power terminal 1 can be significantly reduced, the risk of thermal failure can be reduced, and at the same time, the integration degree of the power module can be improved.

[0039] Embodiment 2

[0040] This embodiment makes further improvements on the basis of Embodiment 1. Specifically, please refer to Figure 5 , a first groove 601 is provided on the surface of the first convex structure 6 in Embodiment 1 facing the power terminal 1, and a second convex structure 9 adapted to the first groove 601 is provided on the power terminal 1, and the second convex structure 9 faces the first groove 601. There is a gap between the second convex structure 9 and the first groove 601, and the gap is filled with an insulating and heat-conducting material structure 5.

[0041] The second convex structure 9 can be a structure integral with the power terminal 1, then the second convex structure 9 can be of the same material as the power terminal 1. The second convex structure 9 can also be a structure integral with the insulating and heat-conducting material structure 5, then the second convex structure 9 can be of the same material as the insulating and heat-conducting material structure 5, and the second convex structure 9 is thermally connected to the power terminal 1 through a heat-conducting material. To obtain a better heat-conducting effect, in this embodiment, it is preferred that the second convex structure 9 is integrally formed with the power terminal 1, then the second convex structure 9 is preferably of the same material as the power terminal 1.

[0042] Since an insulating layer 10 is provided on the outer periphery of the first convex structure 6, therefore, through the insulating layer 10 and the insulating and heat-conducting material structure 5 to form the outer insulation of the first convex structure 6, it is possible to reduce the working temperature of the power terminal 1 while reducing the short-circuit risk between the power terminal 1 and the radiator 4.

[0043] Embodiment 3

[0044] In this embodiment, the power terminal 1 is provided with a concave section bent toward the heat dissipation substrate 401. Since the distance between the concave section and the first surface of the heat dissipation substrate 401 is small, therefore, the concave section is directly thermally connected to the heat dissipation substrate 401 through the insulating and heat-conducting material structure 5.

[0045] As an embodiment, please refer to Figure 6 , the concave section 101 is located at the middle position of the power terminal 1, the concave section 101 is formed by bending the middle part of the power terminal 1 toward the heat dissipation substrate 401, and the concave section 101 is directly thermally connected to the heat dissipation substrate 401 through the insulating and heat-conducting material structure 5.

[0046] As a second embodiment, please refer to Figure 7 , the concave section 101' is located at the end of the power terminal 1 far from the ceramic substrate 3, that is, the concave section 101' is formed by bending one end of the power terminal 1 far from the ceramic substrate 3 toward the heat dissipation substrate 401, and the concave section 101' is directly thermally connected to the heat dissipation substrate 401 through the insulating and heat-conducting material structure 5.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power module, characterized in that: The invention comprises a power device, a ceramic substrate, a heat sink and a power terminal, wherein the heat sink comprises a heat sink substrate and a heat sink assembly, wherein the heat sink substrate comprises a first surface and a second surface arranged opposite to each other, wherein the ceramic substrate is arranged on the first surface of the heat sink substrate, and the heat sink assembly is arranged on the second surface of the heat sink substrate; the power device is arranged on the ceramic substrate; the power terminal is located at an edge position of the upper surface of the ceramic substrate, one end of the power terminal is connected to the ceramic substrate, and the middle position of the power terminal is thermally connected to the first surface of the heat sink substrate through an insulating thermal conductive material structure; A first protrusion structure is provided on the first surface of the heat dissipation substrate, a first groove is provided on the surface of the first protrusion structure facing the power terminal, a second protrusion structure adapted to the first groove is provided at the middle position of the power terminal, a gap is provided between the second protrusion structure and the first groove, and the gap is filled with the insulating heat conductive material structure; Alternatively, a concave section bent toward the heat dissipation substrate is provided in the middle of the power terminal, and the concave section is thermally connected to the heat dissipation substrate via the insulating heat conductive material structure.

2. The power module according to claim 1, characterized in that: The first protrusion structure is integrally formed with the heat dissipation substrate, and the first protrusion structure and the heat dissipation substrate are made of the same material.

3. The power module according to claim 1, characterized in that: An insulating layer is also provided on the periphery of the first protruding structure.

4. The power module according to claim 1, characterized in that: The heat dissipation substrate completely encloses the projection area of ​​the ceramic substrate.

5. The power module according to claim 1, characterized in that: The thermal conductivity of the insulating thermally conductive material structure is greater than 2 W / m·K.

6. The power module according to claim 1, characterized in that: The insulating heat-conducting material structure is a polymer structure.

7. The power module according to claim 1, characterized in that: The insulating heat-conducting material structure is a ceramic structure.

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