Power semiconductor device and method for manufacturing a power semiconductor device

Abstract

The present application is to solve the problem of insufficient contact of the heat dissipation surface of the power semiconductor device and the reduction of heat dissipation performance. The power semiconductor device of the present application makes the heat conduction layer (5) abut against the heat dissipation surface (4a) of the circuit body (100), and makes the heat dissipation member (7) abut against the outside of the heat conduction layer (5) on the side of the heat dissipation surface (4a) of the circuit body (100). The fixing member (8) is made to abut against the side of the circuit body opposite to the heat dissipation surface. Then, the connecting member (9) is made to penetrate the end portions of the heat dissipation member and the fixing member. Fig. 3 shows the state before the bolt and the nut of the fastening connecting member, and the heat dissipation member is kept in the shape of being bent in such a way that the central portion thereof protrudes toward the side of the circuit body. The bolt and the nut of the fastening connecting member are fixedly secured in such a way as to sandwich the circuit body at both ends of the heat dissipation member and the fixing member. The heat dissipation member is elastically deformed, and the heat dissipation member abuts against the heat dissipation surface of the circuit body through the heat conduction layer, and surface pressure is applied from the heat dissipation member to the heat dissipation surface.

Description

Technical Field

[0001] This invention relates to a power semiconductor device and a method for manufacturing the power semiconductor device. Background Technology

[0002] In recent years, hybrid and electric vehicles have become increasingly popular in order to reduce their environmental impact. Improving the performance of components used in hybrid and electric vehicles is a key focus, and power conversion devices that convert direct current to alternating current are no exception, requiring miniaturization and cost reduction.

[0003] To miniaturize power semiconductor devices, which generate a lot of heat in the electronic components constituting power conversion devices, it is necessary to improve cooling performance. In Patent Document 1, a fastening force is applied to the outer periphery of the power semiconductor device to fix the heat dissipation surface of the power semiconductor device to the cooling surface of the housing. Existing technical documents Patent documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2017-212401 Summary of the Invention The problem that the invention aims to solve

[0005] In the past, the heat dissipation surface of power semiconductor devices was not sufficiently close, resulting in reduced heat dissipation performance. Problem-solving methods

[0006] The power semiconductor device of the present invention includes: a circuit body in which a power semiconductor element is built; a first heat dissipation member disposed on a first heat dissipation surface side of the circuit body to dissipate heat from the circuit body; and a fixing member disposed on the side of the circuit body opposite to the first heat dissipation surface, wherein the first heat dissipation member, which is bent and protrudes toward the center of the first heat dissipation surface side, is elastically deformed to fit tightly against the first heat dissipation surface side by connecting and fixing the first heat dissipation member and the fixing member. In the manufacturing method of the power semiconductor device of the present invention, a first heat dissipation member that is bent and protrudes toward the center of the circuit body is disposed on the first heat dissipation surface of the circuit body in which the power semiconductor element is built in, and a fixing member is disposed on the side of the circuit body opposite to the first heat dissipation surface. The first heat dissipation member and the fixing member are connected and fixed so that the first heat dissipation member is elastically deformed and surface pressure is applied to the first heat dissipation surface of the circuit body. The method for manufacturing a power semiconductor device of the present invention comprises: a first heat dissipation member protruding towards the center of the circuit body on a first heat dissipation surface of a circuit body in which a power semiconductor element is incorporated; a second heat dissipation member protruding towards the center of the circuit body on a second heat dissipation surface on the opposite side of the first heat dissipation surface of the circuit body; the first heat dissipation member and the second heat dissipation member are connected and fixed so that the first heat dissipation member and the second heat dissipation member are elastically deformed to apply surface pressure to the first heat dissipation surface and the second heat dissipation surface of the circuit body. Invention Effects

[0007] According to the present invention, the tightness of the contact with the heat dissipation surface can be improved, thereby improving the heat dissipation performance. Attached Figure Description

[0008] Figure 1 It is a cross-sectional view of the circuit. Figure 2 This is a cross-sectional view of a power semiconductor device, showing the first process. Figure 3 This is a cross-sectional view of a power semiconductor device, showing the second process. Figure 4 This is a cross-sectional view of a power semiconductor device, showing the third process. Figure 5 (A) and (B) are simplified cross-sectional views of the heat dissipation component before and after fixing. Figure 6 It refers to the surface pressure distribution of the heat conduction layer. Figure 7 (A) and (B) are simplified cross-sectional views of the heat dissipation component before and after fixing in the comparative example. Figure 8 This is the surface pressure distribution of the heat-conducting layer in the comparative example. Figure 9 This is a cross-sectional view of a modified example 1 of a power semiconductor device. Figure 10 This is a cross-sectional view of a modified example 2 of a power semiconductor device. Figure 11 This is a cross-sectional view showing a modified example 3 of the heat dissipation component. Figure 12 This is a cross-sectional view of the power semiconductor device according to the second embodiment, showing the first process. Figure 13 This is a cross-sectional view of the power semiconductor device according to the second embodiment, showing the second process. Figure 14 This is a cross-sectional view of a modified example 4 of a power semiconductor device. Detailed Implementation

[0009] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following description and drawings are examples for illustrating the present invention; appropriate omissions and simplifications have been made to clarify the description. The present invention can also be implemented in various other ways. Unless otherwise specified, the constituent elements can be singular or plural.

[0010] To facilitate understanding of the invention, the positions, sizes, shapes, and extents of the constituent elements shown in the accompanying drawings sometimes do not represent their actual positions, sizes, shapes, and extents. Therefore, the invention is not necessarily limited to the positions, sizes, shapes, and extents shown in the accompanying drawings.

[0011] [First Implementation Method] Figure 1 This is a cross-sectional view of circuit body 100. Circuit body 100 is integrated into power semiconductor device 200, which will be described later.

[0012] like Figure 1 As shown, the circuit body 100 is composed of a power semiconductor element 1, a bonding material 2, a first conductor 3, an insulating layer 4, and a sealing resin 10. The back electrode of the power semiconductor element 1 is bonded to the first conductor 3 using the bonding material 2, and a thermally conductive insulating layer 4 is connected to the surface of the first conductor 3 opposite to the surface where the power semiconductor element 1 is connected. Then, the insulating layer 4 is sealed with the sealing resin 10 so that its surface is exposed, thereby forming the circuit body 100. The surface of the insulating layer 4 exposed from the sealing resin 10 becomes the heat dissipation surface 4a of the circuit body 100.

[0013] The bonding material 2 is formed from solder material, sintering material, etc. The first conductor 3 is formed, for example, from copper, copper alloy, or aluminum, aluminum alloy, etc.

[0014] The insulating layer 4 is a component that conducts heat generated from the power semiconductor element 1 to the heat dissipation component 7 described later, and is formed of a material with high thermal conductivity and high insulation withstand voltage. For example, ceramics such as alumina, aluminum nitride, and silicon nitride are used, or insulating sheets or adhesives containing micro powders of these materials are used.

[0015] Figure 2 This is a cross-sectional view of a power semiconductor device 200, showing the first step in manufacturing the power semiconductor device 200 with the necessary components configured.

[0016] like Figure 2 As shown, the heat conduction layer 5 is disposed on one side of the heat dissipation surface 4a of the circuit body 100. The heat conduction layer 5 uses grease, thermal interface material (TIM), etc.

[0017] Furthermore, the heat dissipation member 7 is disposed on the outer side of the heat conduction layer 5 on the heat dissipation surface 4a side of the circuit body 100. The heat dissipation member 7 has a shape that is bent so as to bulge towards the circuit body 100 from its central portion. The heat dissipation member 7 is shown as an example of a porous tube cooling water channel with multiple tubular cooling water channels 7a that serve as flow paths for cooling water. Holes 7b are provided at both ends of the heat dissipation member 7 for the connecting member 9, which will be described later, to pass through.

[0018] Regarding the shape of the heat dissipation member 7, which bends towards the circuit body 100, it is formed using a metal mold with a bending shape when processed by extrusion molding. This allows the bent heat dissipation member 7 to be formed without increasing the number of processes or cost. Alternatively, it can be warped by stamping to form the bent heat dissipation member 7. The cooling water pipe 7a is also processed by extrusion molding. The heat dissipation member 7 is formed from a thermally conductive component, such as Cu, Cu alloys, Cu-C, Cu-CuO composite materials, or Al, Al alloys, AlSiC, Al-C composite materials.

[0019] The fixing member 8 is positioned on the side of the circuit body 100 opposite to the heat dissipation surface 4a. The fixing member 8 has a surface parallel to the surface of the circuit body 100 opposite to the heat dissipation surface 4a, and holes 8b are provided at both ends of the fixing member 8 for the connecting member 9 (described later) to pass through. The fixing member 8 is made of composite materials such as Cu, Cu alloy, Cu-C, Cu-CuO, or composite materials such as Al, Al alloy, AlSiC, Al-C, or metals such as stainless steel.

[0020] As described below, the connecting member 9 is a component that connects and fixes the heat dissipation member 7 and the fixing member 8 at their respective ends. The connecting member 9 may use, for example, stainless steel bolts and nuts.

[0021] Figure 3 This is a cross-sectional view of the power semiconductor device 200, showing the second step in manufacturing the power semiconductor device 200 with the necessary components incorporated.

[0022] like Figure 3 As shown, the heat-conducting layer 5 abuts against the heat dissipation surface 4a of the circuit body 100. Furthermore, the heat dissipation member 7 abuts against the outer side of the heat-conducting layer 5 on the heat dissipation surface 4a side of the circuit body 100. The fixing member 8 abuts against the opposite side of the heat dissipation surface 4a of the circuit body 100. Then, the connecting member 9 passes through the respective ends of the heat dissipation member 7 and the fixing member 8. Figure 3 The state before the bolts and nuts fastening the connecting member 9 are shown is shown, with the heat dissipation member 7 maintaining a shape in which its central part is bent toward the circuit body 100.

[0023] Figure 4This is a cross-sectional view of the power semiconductor device 200, showing the third step in manufacturing the power semiconductor device 200.

[0024] like Figure 4 As shown, bolts and nuts of connecting member 9 are securely fixed at both ends of heat dissipation member 7 and fixing member 8 in a manner that clamps the circuit body 100. At this time, heat dissipation member 7 elastically deforms, and as a result, heat dissipation member 7 is in close contact with heat dissipation surface 4a of circuit body 100 through heat conduction layer 5, and surface pressure is applied from heat dissipation member 7 to heat dissipation surface 4a.

[0025] In this embodiment, before the power semiconductor device 200 is manufactured, the heat dissipation member 7 has a curved shape that protrudes towards the circuit body 100 from its central portion, functioning as a leaf spring. Therefore, after the power semiconductor device 200 is manufactured, the heat dissipation member 7 is elastically deformed by the fixing member 8 and the connecting member 9, and is fixed to the heat dissipation surface 4a of the circuit body 100 through the heat conduction layer 5. Thus, without the need for additional leaf springs or other components, surface pressure can be generated over a wide range of the heat conduction layer 5, particularly along the heat dissipation path in the central portion. As a result, the contact thermal resistance of the heat conduction layer 5 is reduced, and the heat dissipation performance of the power semiconductor device 200 is improved.

[0026] Figure 5 (A) is a simplified cross-sectional view of the heat dissipation component 7 before it is fixed. Figure 5 (B) is a simplified cross-sectional view of the heat dissipation component 7 after it is fixed. Figure 6 It is the surface pressure distribution of the heat dissipation component 7 on the heat conduction layer 5 after the heat dissipation component 7 is fixed. Figure 6 The horizontal axis represents the distance from the center 5c of the heat conduction layer 5, which is the dimensionless value obtained by setting the center 5c of the heat conduction layer 5 to 0 and the end 5d of the heat conduction layer 5 to 1. Figure 6 The vertical axis represents the surface pressure exerted by the heat dissipation component 7 on the heat conduction layer 5. Figure 6 This indicates the results of finite element method simulation of the surface pressure distribution of heat conduction layer 5.

[0027] According to this embodiment, the heat dissipation member 7 has a shape that is bent so as to protrude from its central portion toward the circuit body 100. Figure 5 The state of the heat dissipation component 7 shown in (A) before it is fixed becomes Figure 5 In the case of the fixed state of the heat dissipation component 7 shown in (B), the surface pressure distribution of the heat conduction layer 5 is as follows: Figure 6 As shown. Figure 6 As shown by curve P, the surface pressure applied from the heat dissipation member 7 to the heat conduction layer 5 in the compression direction is applied equally over the entire distance.

[0028] That is, the heat dissipation member 7, which is bent in a shape that protrudes towards the circuit body 100, is elastically deformed by connecting members 9 such as bolts and nuts, such that the amount of protrusion of the heat dissipation member 7 towards the circuit body 100 decreases. Preferably, the protrusion of the fixed heat dissipation member 7 is either slightly protruding towards the circuit body 100 or becomes flat. Then, after the heat dissipation member 7 is fixed, as... Figure 6 As shown, a surface pressure in the compression direction is generated across the entire surface of the heat conduction layer 5 at the interface with the heat dissipation member 7. Furthermore, the surface pressure between the heat dissipation member 7 and the heat conduction layer 5 can be set such that the pressure at the center of the circuit body 100 is greater than that at the ends of the circuit body 100. Moreover, the heat dissipation member 7, when fixed by elastic deformation, can be configured to be convex towards the circuit body 100 at its center, or flat across its entire surface towards the circuit body 100.

[0029] For comparison with this embodiment, Figure 7 (A) Figure 7 (B) Figure 8 This is a comparative example using an unbent heat dissipation component 7'.

[0030] Figure 7 (A) is a simplified cross-sectional view of the heat dissipation component 7' before it is fixed. Figure 7 (B) is a simplified cross-sectional view of the heat dissipation component 7' after it has been fixed. Figure 8 This refers to the surface pressure distribution of the heat dissipation component 7' on the heat conduction layer 5 after the heat dissipation component 7' has been fixed. Figure 8 This indicates the results of finite element method simulation of the surface pressure distribution of heat conduction layer 5.

[0031] The heat dissipation component 7' has a flat plate shape, and in the heat dissipation component 7' has a flat Figure 5 The state of the heat dissipation component 7' shown in (A) before it is fixed becomes Figure 5 In the case of the fixed state of the heat dissipation component 7' shown in (B), the surface pressure distribution of the heat conduction layer 5 is as follows: Figure 8 As shown. Figure 8 As shown by curve Q, tension is applied to the central part of the heat conduction layer 5, and surface pressure in the compression direction is applied to both ends of the heat conduction layer 5.

[0032] That is, such as Figure 8 As shown, with the heat dissipation member 7' in the shape of an unbent flat plate fixed at both ends, the heat dissipation member 7' elastically deforms by indenting towards the circuit body 100, using the end of the circuit body 100 as a fulcrum. In this case, as... Figure 8As shown, the surface pressure distribution generated in the heat conduction layer 5 only generates compressive surface pressure near the periphery of the fulcrum at the end of the circuit body 100, and no compressive surface pressure is generated near the center of the heat dissipation component 7.

[0033] exist Figure 4 In the power semiconductor device 200 of this embodiment, when the power semiconductor device 200 is operated, the power semiconductor element 1 generates heat. This heat is conducted to the bonding material 2 and the first conductor 3, further conducted to the insulating layer 4 and the heat-conducting layer 5, and dissipated to the heat dissipation member 7. At this time, the temperature rise is greatest at the periphery of the power semiconductor element 1, so it is important to improve the heat dissipation performance of the area of ​​the heat-conducting layer 5 close to the power semiconductor element 1. That is, compared with the end of the heat-conducting layer 5 away from the circuit body 100 of the power semiconductor element 1, the compressibility surface pressure of the heat-conducting layer 5 does not decrease near the central part of the power semiconductor element 1, so the power semiconductor device 200 of this embodiment can obtain high heat dissipation performance.

[0034] like Figure 4 As shown, in order to elastically deform and fix the heat dissipation member 7, it is necessary to clamp the circuit body 100 with connecting members 9 such as bolts and nuts, and apply a load to both ends of the heat dissipation member 7 from the opposite side. In this case, it is preferable that the rigidity of the load-bearing portion at the end of the heat dissipation member 7 is higher than the rigidity of the heat dissipation portion (i.e., the elastically deformable portion) at the center of the heat dissipation member 7. By making the rigidity of the load-bearing portion at the end higher than the rigidity of the heat dissipation portion (i.e., the elastically deformable portion), the heat dissipation portion can be effectively elastically deformed when a heavy load is applied by forcibly displacing the end with the connecting members 9 such as bolts. For example, it is preferable that the plate thickness of the load-bearing portion of the heat dissipation member 7 is greater than the base thickness of the heat dissipation portion provided with cooling water pipes. Therefore, when a heavy load is applied by forcibly displacing the heat dissipation member 7 with the connecting members 9, the heat dissipation portion can be effectively elastically deformed. Then, compressive stress can be generated in a wide region including the central portion of the heat conduction layer 5. As a result, the contact thermal resistance of the heat conduction layer 5 is reduced, and a power semiconductor device 200 with high heat dissipation performance can be realized.

[0035] (Variation Example 1) Figure 9 This is a cross-sectional view showing a modified example of the power semiconductor device 200. Regarding... Figure 4 The same parts are given the same symbol and their descriptions are omitted. In place of... Figure 4 The insulating layer 4 shown is in Figure 9 This is different from the previous one, which has a ceramic substrate 11 with a conductor.

[0036] like Figure 9As shown, the ceramic substrate 11 with conductor has a first conductor layer 11b disposed on one side of the ceramic substrate 11a and a second conductor layer 11c disposed on the other side. The first conductor layer 11b of the ceramic substrate 11 with conductor is connected to the first conductor 3 by a bonding material 12.

[0037] The first conductor layer 11b and the second conductor layer 11c are formed, for example, of copper, copper alloy, or aluminum, aluminum alloy, etc. The bonding material 12 is formed of solder material, sintering material, etc. By using the ceramic substrate 11 with conductors, a power semiconductor device 200 with high voltage resistance and high heat dissipation is provided.

[0038] (Variation Example 2) Figure 10 This is a cross-sectional view showing a modified example of the power semiconductor device 200. Regarding... Figure 4 The same parts are given the same symbol and their descriptions are omitted. Figure 4 The cross-sectional shape of the cooling water pipe 7a of the heat dissipation component 7 shown is different in this modified example.

[0039] In the first embodiment, the cross-sectional shape of the cooling water pipe 7a of the heat dissipation component 7 is shown to be rectangular. In this modified example, as... Figure 10 As shown, the cooling water pipe 7a has a hexagonal cross-sectional shape, and a tapered portion 7c is formed on the sidewall of the cooling water pipe 7a facing the circuit body 100. By forming the tapered portion 7c on the sidewall of the cooling water pipe 7a, the surface pressure of the heat dissipation member 7, which is in close contact with the heat conduction layer 5, can be made more uniform. When the cross-sectional shape of the cooling water pipe 7a is rectangular, the heat dissipation member 7 becomes substantially thinner at the rectangular side facing the circuit body 100, so the surface pressure of the heat dissipation member 7, which is in close contact with the heat conduction layer 5, may be weaker at the location of the cooling water pipe 7a. Furthermore, the cross-sectional shape of the cooling water pipe 7a is not limited to hexagonal; it can also be pentagonal, triangular, etc., as long as the sidewall of the cooling water pipe 7a forms a tapered portion 7c, and the cross-sectional shape of the cooling water pipe 7a tapers towards the circuit body 100. Moreover, the cross-sectional shape of the cooling water pipe 7a can also be elliptical, in which case the tapered portion 7c of the sidewall of the cooling water pipe 7a becomes a curve.

[0040] In the power semiconductor device 200 of this modified example, uniform compressive stress can be generated on the heat conduction layer 5 by the heat dissipation member 7, which can reduce the contact thermal resistance of the heat conduction layer 5 and realize a power semiconductor device 200 with high heat dissipation performance.

[0041] (Variation Example 3) Figure 11 This is a cross-sectional view showing a modified example of the power semiconductor device 200. Components other than the heat dissipation component 7 and... Figure 2Similarly, the structure of the manufactured power semiconductor device 200 is the same as... Figure 4 Same. In this variant, the configuration density of the cooling water pipe 7a is different.

[0042] like Figure 11 As shown, the cooling water pipes 7a provided on the heat dissipation member 7 are densely arranged in the central part of the heat dissipation member 7 and sparsely arranged towards the ends of the heat dissipation member 7. Preferably, the rigidity of the load-bearing portion at the ends of the heat dissipation member 7 is higher than the rigidity of the heat dissipation portion in the central part of the heat dissipation member 7. By making the rigidity of the load-bearing portion at the ends higher than the rigidity of the heat dissipation portion, when a heavy load is applied by forcibly displacing the ends using connecting members such as bolts, the heat dissipation portion can be effectively elastically deformed.

[0043] After the power semiconductor device 200 is manufactured, the heat dissipation component 7 is elastically deformed by the fixing component 8 and the connecting component 9, and the heat dissipation component 7 is fixed in close contact with the heat dissipation surface 4a of the circuit body 100 through the heat conduction layer 5.

[0044] Furthermore, in this modified example, an example is shown where the cross-sectional shape of the cooling water pipe 7a is rectangular. However, as described in Modification 2, the cross-sectional shape of the cooling water pipe 7a can also be hexagonal, pentagonal, triangular, elliptical, etc., forming a conical structure 7c. Further, a large cross-sectional shape of the cooling water pipe 7a can be arranged in the central part of the heat dissipation member 7, and a small cross-sectional shape of the cooling water pipe 7a can be arranged towards the end of the heat dissipation member 7. Additionally, the heat dissipation member 7 shown in this modified example can also be applied to the power semiconductor device 200 described in Modification 1, which is provided with a ceramic substrate 11 containing a conductor. According to this modified example, when the heat dissipation member 7 is subjected to a heavy load by applying a forced displacement using the connecting member 9, the heat dissipation part is effectively elastically deformed, and compressive stress is easily generated near the center of the heat conduction layer 5. In addition, since the temperature of the central part of the power semiconductor element 1, which is close to the heat generation, becomes the highest, heat dissipation can be improved by densely forming water channels in the central part.

[0045] [Second Implementation] Figure 12 This is a cross-sectional view showing the power semiconductor device 210 in this embodiment, illustrating the first process. Regarding the first embodiment... Figure 2 The same reference numerals are used for the same parts of the power semiconductor device 200 shown, and their descriptions are omitted. In this embodiment, instead of Figure 2 The difference lies in the fact that the fixed member 8 shown is equipped with a heat dissipation member 17. The first embodiment shows an example of a power semiconductor device 200 with single-sided cooling, but this embodiment shows an example of a power semiconductor device 210 with double-sided cooling.

[0046] like Figure 12 As shown, each electrode of the power semiconductor element 1 is held by a first conductor 3 and a second conductor 13 arranged face-to-face with each electrode. The power semiconductor element 1 and the first conductor 3 and second conductor 13 are bonded by bonding materials 2 and 12, respectively. The first conductor 3 and second conductor 13 are formed, for example, of copper, copper alloy, or aluminum, aluminum alloy, etc. The bonding materials 2 and 12 are formed of solder material, sintering material, etc. The first conductor 3 is connected to the back electrode of the power semiconductor element 1, and the second conductor 13 is connected to the surface electrode. The second conductor 13 is shown as an example formed from the same component, but it can also be formed by joining multiple components.

[0047] Thermally conductive insulating layers 4 and 14 are attached to the surfaces of the first conductor 3 and the second conductor 13 opposite to the surfaces connected to the power semiconductor element 1. The insulating layers 4 and 14 are components that conduct heat generated from the power semiconductor element 1 to the heat dissipation components 7 and 17, and are formed of materials with high thermal conductivity and high dielectric strength. For example, ceramics such as alumina, aluminum nitride, and silicon nitride, or insulating sheets or adhesives containing micropowders of these materials can be used.

[0048] The circuit body 110 is formed by sealing with sealing resin 10 so that the surfaces of insulating layers 4 and 14 are exposed. The surfaces of insulating layers 4 and 14 exposed from the sealing resin 10 become heat dissipation surfaces 4a and 14a of the circuit body 110.

[0049] Thermally conductive layers 5 and 15 are provided in a manner that allows them to be thermally connected to the heat dissipation surfaces 4a and 14a of the circuit body 110. The thermally conductive layers 5 and 15 can be made of grease, thermal interface material (TIM), or the like. Heat dissipation members 7 and 17 are disposed on the surface of the thermally conductive layers 5 and 15 opposite to the side of the circuit body 110. Heat dissipation members 7 and 17 are disposed in a manner that clamps the circuit body 110, and a connecting member 9 is provided to connect and fix the heat dissipation members 7 and 17 by clamping the circuit body 110 at both ends.

[0050] The heat dissipation components 7 and 17 have a curved shape that protrudes towards the circuit body 110 from their central portion. The heat dissipation components 7 and 17 illustrate an example of a perforated cooling water channel with multiple tubular cooling water passages 7a and 17a that serve as flow paths for cooling water. Holes 7b and 17b, described later, are provided at both ends of the heat dissipation components 7 and 17 for the connecting member 9 to pass through.

[0051] Regarding the shape of the heat dissipation components 7 and 17 that bend towards the circuit body 110, when processing by extrusion molding, a metal mold with a bending shape is used to form them. This allows the bent-shaped heat dissipation components 7 and 17 to be formed without increasing the number of processes or cost. Alternatively, the bent-shaped heat dissipation components 7 and 17 can also be formed by warping through stamping. Furthermore, the cooling water pipes 7a and 17a are processed by extrusion molding. The heat dissipation components 7 and 17 are formed from thermally conductive components, such as composite materials like Cu, Cu alloys, Cu-C, and Cu-CuO, or composite materials like Al, Al alloys, AlSiC, and Al-C.

[0052] As described below, the connecting member 9 is a component that connects and fixes the heat dissipation member 7 and the heat dissipation member 17 at their respective ends. The connecting member 9 may use, for example, stainless steel bolts and nuts.

[0053] Figure 13 This is a cross-sectional view of the power semiconductor device 210 in this embodiment, showing the second process. like Figure 13 As shown, the heat-conducting layers 5 and 15 abut against the heat dissipation surfaces 4a and 14a of the circuit body 110. Furthermore, the heat dissipation member 7 abuts against the outer side of the heat-conducting layer 5 on the heat dissipation surface 4a side of the circuit body 110. The heat dissipation member 17 abuts against the outer side of the heat-conducting layer 15 on the heat dissipation surface 14a side of the circuit body 110. Then, the connecting member 9 passes through the respective ends of the heat dissipation member 7 and the heat dissipation member 17. Figure 13 This indicates the state before the bolts and nuts of the fastening connecting member 9 are tightened, and the heat dissipation members 7 and 17 maintain a bent shape with their central portion protruding towards the circuit body 110.

[0054] Next, the third step of the power semiconductor device 210 in this embodiment will be described. exist Figure 13 In the shown state, the bolts and nuts of the connecting member 9 are securely fixed at both ends of the heat dissipation member 7 and the heat dissipation member 17 in a manner that clamps the circuit body 110. At this time, the heat dissipation member 17 serves as a fixing member for the heat dissipation member 7, and the heat dissipation member 7 serves as a fixing member for the heat dissipation member 17. At this time, the heat dissipation members 7 and 17 elastically deform, resulting in the heat dissipation members 7 and 17 being in close contact with the heat dissipation surfaces 4a and 14a of the circuit body 110 through the heat conduction layers 5 and 15, and surface pressure is applied from the heat dissipation members 7 and 17 to the heat dissipation surfaces 4a and 14a.

[0055] The heat dissipation members 7 and 17, which are curved and protrude towards the circuit body 110, are elastically deformed by the fastening of the connecting member 9, such that the amount of protrusion of the heat dissipation members 7 and 17 towards the circuit body 110 decreases. Preferably, the protrusion of the fixed heat dissipation members 7 and 17 is slightly protruding towards the circuit body 110 or becomes flat. This allows surface pressure in the compression direction to be generated in a wide region, including the center of the heat conduction layers 5 and 15. Furthermore, the surface pressure of the heat dissipation members 7 and 17 in contact with the heat conduction layers 5 and 15 can be set such that the central portion of the circuit body 110 is greater than the end portion. Moreover, the heat dissipation members 7 and 17, in their elastically deformed and fixed state, can be configured such that the central portion of the heat dissipation members 7 and 17 is convex towards the circuit body 110, or that the entire surface of the heat dissipation members 7 and 17 is flat towards the circuit body 110. As a result, the contact thermal resistance of the heat conduction layers 5 and 15 is reduced, enabling the realization of a power semiconductor device 210 with high heat dissipation performance.

[0056] Furthermore, in this embodiment, an example is shown where the cross-sectional shape of the cooling water pipes 7a and 17a is rectangular. However, as described in Variation 2 of the first embodiment, the cross-sectional shape of the cooling water pipes 7a and 17a can also be hexagonal, pentagonal, triangular, elliptical, or other structures forming a conical portion 7c. Moreover, as described in Variation 3 of the first embodiment, the cooling water pipes 7a and 17a provided on the heat dissipation members 7 and 17 are densely formed in the central part of the heat dissipation members 7 and 17, and sparsely formed towards the ends of the heat dissipation members 7 and 17. Furthermore, as described in Variation 1 of the first embodiment, a ceramic substrate with a conductor can be provided instead of the insulating layers 4 and 14.

[0057] According to this embodiment, when the circuit body 110 is cooled on both sides, heat dissipation members 7 and 17, which are bent in a shape that protrudes toward the circuit body 110, are arranged to clamp the circuit body 110 and are fixed by elastic deformation of the heat dissipation members 7 and 17. Thus, a power semiconductor device 210 with high heat dissipation can be obtained without adding a fixing member 8.

[0058] (Variation Example 4) Figure 14 This is a cross-sectional view showing a modified example of the power semiconductor device 210. Regarding... Figure 13 The same parts are given the same symbol and their descriptions are omitted. Figure 13 The heat dissipation components 7 and 17 shown have different structures.

[0059] Figure 14 This indicates the second step in this variation. For example... Figure 14As shown, heat dissipation components 18 and 19 have heat dissipation fins 18a and 19a on their surfaces. The shape of the heat dissipation fins 18a and 19a can also be a pin heat dissipation fin, a straight heat dissipation fin, or a corrugated heat dissipation fin.

[0060] The heat dissipation components 18 and 19 are formed of conductive components, such as composite materials like Cu, Cu alloys, Cu-C, Cu-CuO, or composite materials like Al, Al alloys, AlSiC, Al-C.

[0061] Heat dissipation members 18 and 19 are formed in a curved shape that protrudes from their central portion toward the circuit body 110. Heat dissipation member 18 abuts against the outer side of the heat conduction layer 5 on the heat dissipation surface 4a side of the circuit body 110. Heat dissipation member 19 abuts against the outer side of the heat conduction layer 15 on the heat dissipation surface 14a side of the circuit body 110. Then, connecting member 9 passes through the respective ends of heat dissipation members 18 and 19. Figure 14 The state before the bolts and nuts fastening the connecting member 9 are shown, with the heat dissipation members 18 and 19 maintaining a bent shape in which their central portion protrudes toward the circuit body 110.

[0062] In the third process, Figure 14 In the shown state, bolts and nuts of connecting member 9 are securely fixed at both ends of heat dissipation member 18 and heat dissipation member 19, clamping the circuit body 110. At this time, heat dissipation members 18 and 19 elastically deform, resulting in heat dissipation members 18 and 19 being in close contact with the heat dissipation surfaces 4a and 14a of the circuit body 110 through the heat conduction layers 5 and 15, applying surface pressure from heat dissipation members 18 and 19 to heat dissipation surfaces 4a and 14a. The heat dissipation members 18 and 19 have higher rigidity at their load-bearing ends than at their central portions, thus effectively causing elastic deformation of the central portion when a heavy load is applied by forcibly displacing the ends with connecting members 9 such as bolts. Figure 14 As shown, the thickness of the end portion of the heat dissipation members 18 and 19, which serves as the load-bearing portion, is set to be greater than the thickness of the central portion. Preferably, the protrusion of the fixed heat dissipation members 18 and 19 is either slightly protruding towards the circuit body 110 or flat. As a result, surface pressure in the compression direction can be generated in a wide region including the center of the heat conduction layers 5 and 15. Consequently, the contact thermal resistance of the heat conduction layers 5 and 15 is reduced, and a power semiconductor device 210 with high heat dissipation performance can be obtained.

[0063] exist Figure 14 In the figure, the outer cover of the heat sink 18a and 19a of the heat dissipation components 18 and 19 is omitted, but the cover can also be provided to form a flow path for cooling water.

[0064] exist Figure 14The example described is a heat dissipation member 18, 19 with heat sinks 18a, 19a provided on both sides of the circuit body 110, but it can also be combined with... Figure 4 Similarly, a heat dissipation component 18 with a heat sink 18a is provided on one side of the circuit body 100.

[0065] In the embodiments described above, an example is shown where the sealing resin 10 includes insulating layers 4 and 14, and is sealed except for the heat dissipation surfaces 4a and 14a. However, the sealing resin 10 can also seal up to the first conductor 3 and the second conductor 13. The same effect can be obtained if the insulating layers 4 and 14 are connected to the first conductor 3 and the second conductor 13, respectively.

[0066] Furthermore, in the above embodiments, the case where there is only one power semiconductor element 1 has been described, but it can also be applied to power semiconductor devices 200 and 210 that have multiple power semiconductor elements 1 built in.

[0067] According to the embodiment described above, the heat dissipation members 7, 17, 18, and 19, which are bent in a manner protruding towards the central portion of the circuit bodies 100 and 110, are elastically deformed, causing the heat dissipation members 7, 17, 18, and 19 to function as leaf springs. The heat dissipation members 7, 17, 18, and 19 are pressed against the heat dissipation surface of the central portion of the circuit bodies 100 and 110, generating surface pressure in the compression direction. As a result, the contact thermal resistance between the heat dissipation surface of the circuit bodies 100 and 110 and the heat dissipation members 7, 17, 18, and 19 is reduced, enabling the realization of power semiconductor devices 200 and 210 with high heat dissipation performance.

[0068] The following effects can be obtained by implementing the methods described above. (1) The power semiconductor device 200 includes: a circuit body 100 in which a power semiconductor element 1 is built; a heat dissipation member 7 disposed on the heat dissipation surface 4a side of the circuit body 100 and dissipating heat from the circuit body 100; and a fixing member 8 disposed on the side of the circuit body 100 opposite to the heat dissipation surface 4a. The heat dissipation member 7, which is bent and protrudes towards the center of the heat dissipation surface 4a side, is elastically deformed to fit tightly against the heat dissipation surface 4a side by connecting the fixing heat dissipation member 7 and the fixing member 8. As a result, the tightness of the fit against the heat dissipation surface can be improved, thereby improving the heat dissipation performance.

[0069] (2) In the manufacturing method of the power semiconductor device 200, a curved heat dissipation member 7 protruding towards the center of the circuit body 100 is disposed on the heat dissipation surface 4a of the circuit body 100 in which the power semiconductor element 1 is built in. A fixing member 8 is disposed on the side of the circuit body 100 opposite to the heat dissipation surface 4a. The heat dissipation member 7 and the fixing member 8 are connected and fixed, so that the heat dissipation member 7 elastically deforms and applies surface pressure to the heat dissipation surface 4a of the circuit body 100. As a result, the tightness of the contact with the heat dissipation surface can be improved, thereby improving the heat dissipation performance.

[0070] (3) In the manufacturing method of the power semiconductor device 210, a curved heat dissipation member 7 protruding towards the center of the circuit body 110 is disposed on the heat dissipation surface 4a of the circuit body 110 in which the power semiconductor element 1 is built in. On the heat dissipation surface 14a of the circuit body 110 opposite to the heat dissipation surface 4a, a curved heat dissipation member 17 protruding towards the center of the circuit body 110 is disposed. The heat dissipation member 7 and the heat dissipation member 17 are connected and fixed so that the heat dissipation member 7 and the heat dissipation member 17 are elastically deformed, and surface pressure is applied to the heat dissipation surface 4a and the heat dissipation surface 14a of the circuit body 110. As a result, the tightness of the contact with the heat dissipation surface can be improved, and the heat dissipation performance can be improved.

[0071] This invention is not limited to the embodiments described above. Other embodiments within the scope of the technical concept of this invention are also included within the scope of this invention, as long as they do not impair the characteristics of this invention. Additionally, it may be a structure that combines the above embodiments and multiple variations. Symbol Explanation

[0072] 1…power semiconductor element, 2…bonding material, 3…first conductor, 4, 14…insulating layer, 4a, 14a…heat dissipation surface, 5, 15…heat conduction layer, 7, 17, 18, 19…heat dissipation component, 7a, 17a…cooling water pipe, 7c…cone, 8…fixing component, 9…connecting component, 10…sealing resin, 11…ceramic substrate with conductor, 11a…ceramic substrate, 11b…first conductor layer, 11c…second conductor layer, 12…bonding material, 13…second conductor, 18a, 19a…heat sink, 100, 110…circuit body, 200, 210…power semiconductor device.

Claims

1. A power semiconductor device, characterized in that, have: The circuit body contains power semiconductor components; A first heat dissipation component is disposed on the first heat dissipation surface side of the circuit body to dissipate heat from the circuit body. as well as A fixing member is disposed on the side of the circuit body opposite to the first heat dissipation surface. By connecting and fixing the first heat dissipation component and the fixing component, the first heat dissipation component, which is bent and protrudes towards the center of the first heat dissipation surface, elastically deforms in a manner that it is in close contact with the first heat dissipation surface. The first heat dissipation component has multiple cooling water pipes formed by extrusion molding. The shape of the first heat dissipation component is formed using a bent metal mold during extrusion molding, or by warping during stamping. The bending stiffness of the portion of the first heat dissipation component that connects and fixes the first heat dissipation component and the fixing component is higher than the bending stiffness of the central portion of the first heat dissipation component. In the elastically deformed state, the first heat dissipation component is either convex or flat, protruding toward the circuit body.

2. The power semiconductor device according to claim 1, characterized in that, The fixing member is a second heat dissipation member disposed on the second heat dissipation surface side, which is the side opposite to the first heat dissipation surface side. By connecting and fixing the first heat dissipation component and the second heat dissipation component, the first heat dissipation component, which is bent and protrudes towards the center of the first heat dissipation surface, and the second heat dissipation component, which is bent and protrudes towards the center of the second heat dissipation surface, are elastically deformed in such a way that the circuit body is tightly attached to the first heat dissipation surface and the second heat dissipation surface respectively.

3. The power semiconductor device according to claim 2, characterized in that, The bending stiffness of the first heat dissipation component and the second heat dissipation component in the portion that connects and fixes the first heat dissipation component and the second heat dissipation component is higher than the bending stiffness of the central portion of the first heat dissipation component and the second heat dissipation component, respectively.

4. The power semiconductor device according to claim 1, characterized in that, The thickness of the first heat dissipation component, which connects and fixes the first heat dissipation component and the fixing component, is greater than the thickness of the central portion of the first heat dissipation component.

5. The power semiconductor device according to claim 3, characterized in that, The thickness of the plates of the first heat dissipation component and the second heat dissipation component that connect and fix the first heat dissipation component and the second heat dissipation component is greater than the thickness of the plate of the central part of the first heat dissipation component and the second heat dissipation component, respectively.

6. The power semiconductor device according to any one of claims 2, 3, and 5, characterized in that, In the elastically deformed state, the first heat dissipation component and the second heat dissipation component are either convex or flat, protruding toward the circuit body.

7. The power semiconductor device according to claim 2, characterized in that, The first heat dissipation component and the second heat dissipation component have multiple cooling water pipes formed by extrusion molding.

8. The power semiconductor device according to claim 1 or 7, characterized in that, The sidewall inside the cooling water pipe forms a cone-shaped portion facing the circuit body.

9. The power semiconductor device according to claim 7, characterized in that, The plurality of cooling water pipes are arranged in a dense configuration in the central portion of the first heat dissipation component and the second heat dissipation component.

10. The power semiconductor device according to claim 2, characterized in that, The first heat dissipation component and the second heat dissipation component have heat dissipation fins.

11. A method for manufacturing a power semiconductor device, characterized in that, A first heat dissipation member, which curves and protrudes towards the center of the circuit body, is disposed on the first heat dissipation surface of the circuit body containing power semiconductor components. A fixing member is disposed on the side of the circuit body opposite to the first heat dissipation surface. The first heat dissipation component and the fixing component are connected and fixed, so that the first heat dissipation component can be elastically deformed to apply surface pressure to the first heat dissipation surface of the circuit body. The first heat dissipation component has multiple cooling water pipes formed by extrusion molding. The shape of the first heat dissipation component is formed using a bent metal mold during extrusion molding, or by warping during stamping. The bending stiffness of the portion of the first heat dissipation component that connects and fixes the first heat dissipation component and the fixing component is higher than the bending stiffness of the central portion of the first heat dissipation component. In the elastically deformed state, the first heat dissipation component is either convex or flat, protruding toward the circuit body.

12. A method for manufacturing a power semiconductor device, characterized in that, A first heat dissipation member, which curves and protrudes towards the center of the circuit body, is disposed on the first heat dissipation surface of the circuit body containing power semiconductor components. On the second heat dissipation surface of the circuit body, opposite to the first heat dissipation surface, a curved second heat dissipation member protruding towards the center of the circuit body is disposed. The first heat dissipation component and the second heat dissipation component are connected and fixed so that the first heat dissipation component and the second heat dissipation component can be elastically deformed to apply surface pressure to the first heat dissipation surface and the second heat dissipation surface of the circuit body. The first heat dissipation component and the second heat dissipation component have multiple cooling water pipes formed by extrusion molding. The shapes of the first and second heat dissipation components are formed using a bent metal mold during extrusion molding, or by warping during stamping. The bending stiffness of the first heat dissipation component, which connects and fixes the first heat dissipation component and the second heat dissipation component, is higher than the bending stiffness of the central portion of the first heat dissipation component. In the elastically deformed state, the first heat dissipation component is either convex or flat, protruding toward the circuit body.

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