Power semiconductor device and power conversion device

Abstract

A first surface shape of the module base (10) and a second surface shape of the heat sink base (14) are fitted to each other, whereby the module base (10) and the heat sink base (14) are fixed to each other. One of the first surface shape and the second surface shape includes a first convex portion (51) and a second convex portion (52), and the other includes a first concave portion (61) fitted to the first convex portion (51) and a second concave portion (62) fitted to the second convex portion (52). The first convex portion (51) has a distal end in contact with the first concave portion (61), and the second convex portion (52) has a distal end (TE) separated from the second concave portion (62).

Description

Technical Field

[0001] The present disclosure relates to a power semiconductor device and a power conversion device, and more particularly to a power semiconductor device having a heat sink base and a power conversion device having the power semiconductor device. Background Art

[0002] International Publication No. 2018 / 079396 (Patent Document 1) discloses a semiconductor device. The semiconductor device includes a power module and a heat dissipation component. The power module includes a semiconductor element, a metal component on which the semiconductor element is mounted, and a seal that seals the semiconductor element and exposes at least a portion of the metal component. Any one of a plurality of recesses and protrusions is formed on the metal component, and the other of a plurality of recesses and protrusions is formed on the heat dissipation component. The metal component and the heat dissipation component are integrated at a plurality of recesses and protrusions where a plurality of recesses and a plurality of protrusions contact. The dimension in the height direction of a first recessed convex portion as a part of a plurality of recessed convex portions is larger than the dimension in the height direction of a second recessed convex portion other than the first recessed convex portion among the plurality of recessed convex portions.

[0003] In the above-mentioned method for manufacturing a semiconductor device, the concave and convex parts are caulked to form a whole with the metal component and the heat sink component. At this time, the first concave part and the first convex part constituting the first concave-convex part having a larger dimension in the height direction than the second concave-convex part have the function of offsetting the power module with respect to the heat sink in a manner inclined with respect to the original joining manner so as not to form a whole, in other words, have the function of a guide mechanism.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2018 / 079396 Summary of the invention

[0007] Problems to be solved by the invention

[0008] If the relative positions of the components that are integrated by the caulking process deviate from the ideal positions in the design due to at least one of the inclination between the components and the overlap deviation between the components, the load required to complete the caulking process, that is, the necessary load, sometimes becomes larger. According to the above-mentioned semiconductor device, the positional deviation can be suppressed by the guide mechanism, but it may not be possible to fully suppress the positional deviation. Therefore, even if a guide mechanism is provided, the necessary load may increase due to the positional deviation. In addition, depending on the design of the semiconductor device, the provision of a guide mechanism is sometimes not allowed. If a precise alignment process is performed before the caulking process, a guide mechanism is not required, but the introduction of such a process has a large burden on manufacturing. In addition, not only the positional deviation but also the dimensional error of the components will lead to an increase in the necessary load.

[0009] As described above, due to manufacturing deviations that cause at least one of positional offset and dimensional error, the load required for the caulking process may increase. On the other hand, simply adjusting the design of the concave and convex parts to reduce the required load can easily lead to a decrease in the strength of the caulking joint and an increase in the thermal contact resistance in the caulking joint.

[0010] The present disclosure is completed to solve the above-mentioned problems, and one of its purposes is to provide a power semiconductor device that can suppress the increase in the necessary load of the caulking process caused by manufacturing deviation, and can also suppress the decrease in the strength of the caulking joint and the increase in thermal contact resistance in the caulking joint.

[0011] Means for solving problems

[0012] The power semiconductor device disclosed in the present invention includes a module base, a semiconductor element, a resin sealing portion, and a heat sink base. The module base has a mounting surface and a back surface opposite to the mounting surface in the thickness direction. The semiconductor element is mounted on the mounting surface of the module base. The resin sealing portion seals the semiconductor element on the mounting surface of the module base. The heat sink base has: a mounting surface, which is mounted on the back surface of the module base; and a heat dissipation surface, which is opposite to the mounting surface in the thickness direction. The first surface shape of the back surface of the module base and the second surface shape of the mounting surface of the heat sink base are mutually fitted, so that the back surface of the module base and the mounting surface of the heat sink base are fixed to each other. One of the first surface shape and the second surface shape includes a first convex portion and a second convex portion, and the other includes a first concave portion fitted with the first convex portion and a second concave portion fitted with the second convex portion. The first convex portion has a terminal end in contact with the first concave portion, and the second convex portion has a terminal end separated from the second concave portion.

[0013] Effects of the Invention

[0014] According to the present disclosure, it is possible to suppress an increase in the load required for caulking due to manufacturing variations, and also to suppress a decrease in the strength of caulking and an increase in thermal contact resistance in caulking. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a cross-sectional view schematically showing the structure of the power semiconductor device according to the first embodiment.

[0016] Figure 2 It roughly indicates Figure 1 2 is a cross-sectional view of a power semiconductor device before a module base and a heat sink base are caulked and joined.

[0017] Figure 3 It roughly indicates Figure 2 A partial top view of the structure on the back side of the module base is shown.

[0018] Figure 4 Yes means Figure 3 A partial top view of a modified example of the back side of the module base is shown.

[0019] Figure 5 Yes means Figure 3 A partial top view of a modified example of the back side of the module base is shown.

[0020] Figure 6 It roughly indicates Figure 1 A partial cross-sectional view of the structure of the second protrusion and the second recess shown.

[0021] Figure 7 This is a partial cross-sectional view schematically showing a state immediately before a caulking step in a method for manufacturing a power semiconductor device according to a comparative example.

[0022] Figure 8 This is a partial cross-sectional view schematically showing a state immediately after the caulking step in the method for manufacturing a power semiconductor device according to the comparative example is completed.

[0023] Fig. 9 This is a partial cross-sectional view schematically showing a state immediately before the caulking step in the method for manufacturing the power semiconductor device according to the first embodiment.

[0024] Fig.10 This is a partial cross-sectional view schematically showing a state immediately after the caulking step in the method for manufacturing a power semiconductor device according to the comparative example is completed.

[0025] Fig.11 Yes means Figure 2 A cross-sectional view of a modified example of the heat sink shown.

[0026] Fig.12 Yes means Figure 2 A cross-sectional view of a modified example of the heat sink shown.

[0027] Fig.13 It roughly indicates Figure 2 A cross-sectional view of a modification of the power semiconductor device shown is a state before a module base and a heat sink base are caulked and joined.

[0028] Fig.14 is an example Fig.13 A partial cross-sectional view showing the dimensions of the module base and heat sink base.

[0029] Fig.15 It roughly indicates Figure 2A cross-sectional view of a modification of the power semiconductor device shown is a state before a module base and a heat sink base are caulked and joined.

[0030] Fig.16 It roughly indicates Figure 2 A cross-sectional view of a modification of the power semiconductor device shown is a state before a module base and a heat sink base are caulked and joined.

[0031] Fig.17 It roughly indicates Figure 2 A cross-sectional view of a modification of the power semiconductor device shown is a state before a module base and a heat sink base are caulked and joined.

[0032] Fig.18 This is a cross-sectional view schematically showing a state immediately before the caulking step in the method for manufacturing the power semiconductor device according to the first embodiment.

[0033] Fig.19 This is a cross-sectional view schematically showing a state during a caulking step in the method for manufacturing a power semiconductor device according to the first embodiment.

[0034] Fig. 20 This is a cross-sectional view schematically showing a state immediately after the caulking step in the method for manufacturing the power semiconductor device according to the first embodiment is completed.

[0035] Fig.21 This is a plan view for explaining a modified example of the caulking step in the method for manufacturing the power semiconductor device according to the first embodiment.

[0036] Fig. 22 This is a cross-sectional view schematically showing a modification of the caulking step in the method for manufacturing the power semiconductor device according to the first embodiment.

[0037] Fig.23 This is a cross-sectional view schematically showing the structure of a power semiconductor device according to the second embodiment.

[0038] Fig.24 It roughly indicates Fig.23 2 is a cross-sectional view of a power semiconductor device before a module base and a heat sink base are caulked and joined.

[0039] Fig.25 It is a cross-sectional view schematically showing the structure of a power semiconductor device according to a third embodiment.

[0040] Fig.26 This is a cross-sectional view schematically showing one step in the method for manufacturing a power semiconductor device according to the third embodiment.

[0041] Fig. 27This is a cross-sectional view schematically showing one step in the method for manufacturing a power semiconductor device according to the third embodiment.

[0042] Fig.28 This is a block diagram schematically showing the configuration of a power conversion device according to a fourth embodiment. DETAILED DESCRIPTION

[0043] Hereinafter, the embodiments will be described based on the accompanying drawings. In addition, in the following drawings, the same or corresponding parts are marked with the same reference numerals, and their descriptions are not repeated. In addition, in this specification, the term "metal" refers not only to pure metals but also alloys unless otherwise specified.

[0044] <Implementation method 1>

[0045] Figure 1 1 is a cross-sectional view schematically showing the structure of a power semiconductor device 101 according to Embodiment 1. The power semiconductor device 101 includes a power module portion 1 and a heat sink portion 2. The power semiconductor device 101 is a device in which the power module portion 1 and the heat sink portion 2 are integrated, in other words, a heat sink-integrated power module. Figure 2 This is a cross-sectional view schematically showing the state before the module base 10 of the power module part 1 and the heat sink base 14 of the heat sink part 2 are joined by the caulking process. In addition, hereinafter, the caulking of the module base and the heat sink base is sometimes referred to as "heat sink caulking". In addition, the timing of heat sink caulking in the manufacture of the power semiconductor device 101 is not limited to one, and this is also the same in other embodiments. Figure 2 This corresponds to the case where the heat sink is swaged separately in the final step in the manufacturing process.

[0046] The power module unit 1 includes a module base 10 , at least one semiconductor element 5 (semiconductor chip), and a resin sealing unit 4 (molding member). In addition, the power module unit 1 may include a lead frame 3 .

[0047] The module base 10 has a mounting surface PM and a thickness direction ( Figure 1 and Figure 2The back side PO opposite to the mounting surface PM in the longitudinal direction (in the longitudinal direction) of the module base 10. The semiconductor element 5 is mounted on the mounting surface PM of the module base 10. In this assembly, for example, a bonding material 6 composed of solder can be used. The semiconductor element 5 includes a power semiconductor element. The power semiconductor element is, for example, a switching element or a freewheeling diode. The semiconductor element 5 can be a semiconductor element using a wide bandgap semiconductor, that is, a wide bandgap semiconductor element. The wide bandgap semiconductor is, for example, SiC (silicon carbide). The resin sealing portion 4 seals the semiconductor element 5 on the mounting surface PM of the module base 10. The lead frame 3 (metal electrode) can be mounted on the mounting surface PM of the module base 10, and an insulating sheet 9 can be provided between the lead frame 3 and the mounting surface PM. The lead frame 3 is electrically connected to the semiconductor element 5. In addition, for this electrical connection, a wiring component (typically a bonding wire) not shown in the figure can be used. The lead frame 3 has a portion covered by the resin sealing portion 4 and a portion protruding outward from the resin sealing portion 4.

[0048] The heat sink unit 2 includes a heat sink base 14. The heat sink base 14 has a mounting surface PF mounted on the back surface PO of the module base 10 and a heat dissipation surface PR opposite to the mounting surface PF in the thickness direction. In addition, in the present embodiment, the heat sink unit 2 includes heat dissipation fins 15 mounted on the heat dissipation surface PR of the module base 10. The heat dissipation fins 15 are mounted on the caulking portion 11 of the module base 10 by caulking. Hereinafter, this caulking is sometimes referred to as "fin caulking".

[0049] The module base 10 of the power module part 1 and the heat sink base 14 of the heat sink part 2 are prepared separately and then joined to each other by heat sink caulking. Therefore, the design of the heat sink part 2 can be changed without changing the design of the module base 10, and the heat dissipation capacity for removing heat from the semiconductor element 5 can be adjusted by this change. As design elements of the heat sink part 2 for adjusting the heat dissipation capacity, there are, for example, the size of the heat sink base 14 in the in-plane direction perpendicular to the thickness direction, the number of heat dissipation fins 15, the size of each heat dissipation fin 15, etc. By changing the design of the heat sink part 2 according to the required heat dissipation capacity, the design of the common module base 10 can be applied, so the productivity of the power module part 1 can be improved. In addition, there is no need to change the design of the mold used to make the module base 10, so the increase in mold cost can be avoided.

[0050] The module base 10 is made of metal. For example, the module base 10 is made of aluminum or an aluminum alloy and is manufactured by cutting, die casting, forging or extrusion. The heat sink base 14 is made of metal. For example, the heat sink base 14 is made of aluminum or an aluminum alloy and is manufactured by cutting, die casting, forging or extrusion. The heat sink fins 15 are made of, for example, a metal plate (rolled product) such as aluminum or an aluminum alloy.

[0051] like Figure 1 As shown, the surface shape of the back side PO of the module base 10 (hereinafter also referred to as the "first surface shape") and the surface shape of the mounting surface PF of the heat sink base 14 (hereinafter also referred to as the "second surface shape") are fitted together, so that the back side PO of the module base 10 and the mounting surface PF of the heat sink base 14 are fixed to each other. One of the first surface shape and the second surface shape includes a first convex portion 51 and a second convex portion 52, and the other includes a first concave portion 61 fitted with the first convex portion 51 and a second concave portion 62 fitted with the second convex portion 52. Figure 1 and Figure 2 In the example shown, the second surface shape includes a first convex portion 51 and a second convex portion 52 , and the first surface shape includes a first concave portion 61 and a second concave portion 62 .

[0052] Figure 3 The back side PO of the module base 10 is schematically shown. Figure 2 ) is a partial top view of the structure. The plane layout perpendicular to the thickness direction of the recess group 60 including the first recess 61 and the second recess 62 includes a first direction ( Figure 3 in the longitudinal direction) and in a second direction perpendicular to the first direction ( Figure 3 In addition, the convex portion group including the first convex portion 51 and the second convex portion 52 may also have a planar layout corresponding to the above-mentioned planar layout. Figure 4 and Figure 5 They are respectively Figure 3 In these variations, the planar layout of the recess group 60 perpendicular to the thickness direction includes: a plurality of patterns P1 extending along a first direction (longitudinal direction in the figure) and arranged at intervals in a second direction (lateral direction in the figure) perpendicular to the first direction; and at least one pattern P2 extending along a third direction (lateral direction in the figure) different from the first direction. In particular, Figure 5 In the variation example, as shown by the double-dashed line in the figure, a pattern extending discontinuously along the first direction is included.

[0053] Figure 6 : is a partial cross-sectional view schematically showing the structure of the second convex portion 52 and the second concave portion 62 in a cross-sectional view parallel to the thickness direction. The second convex portion 52 has a tip TE separated from the second concave portion 62. Therefore, a gap GP is formed between the second convex portion 52 and the second concave portion 62. Figure 6 In the example, the end TE of the second protrusion 52 is a substantially flat surface ( Figure 6The second protrusion 52 is a surface that protrudes with a substantially uniform height H52 (the lower surface in the middle). The end TE of the second protrusion 52 is separated from the second recess 62, and on the other hand, the side surface of the second protrusion 52 is in contact with the side wall of the second recess 62. The height H52 is preferably greater than 0.5 mm. The end TE of the second protrusion 52 has a width W52 of the second protrusion 52. The second recess 62 has a width W62 at the position of the end TE of the second protrusion 52 in the thickness direction. The width W52 is preferably greater than 65% and less than 100% of the width W62. Here, the width dimension is the dimension in the direction perpendicular to the extension direction, for example Figure 3 to Figure 5 The distance HG between the end TE of the second convex portion 52 and the bottom surface of the second concave portion 62 is greater than zero, and may be greater than 0.1 mm, or may be greater than 0.2 mm.

[0054] The first convex portion 51( Figure 1 ) has a tip in contact with the first recess 61. In a cross-sectional view parallel to the thickness direction ( Figure 1 ), there is no need to form a gap between the first convex portion 51 and the first concave portion 61, but a gap may be formed between the first convex portion 51 and the first concave portion 61. The gap is preferably smaller than the gap GP ( Figure 6 ), preferably having an area of ​​50% or less of the area of ​​the first recess 61. The height H52 ( Figure 6 ) is smaller than the height of the first protrusion 51.

[0055] For the purpose of caulking, surface pressure is at least partially applied between the first protrusion 51 and the first recess 61. It is not necessary to apply surface pressure between the second protrusion 52 and the second recess 62, but surface pressure may be at least partially applied. When surface pressure is applied, the maximum surface pressure between the second protrusion 52 and the second recess 62 is preferably lower than the maximum surface pressure between the first protrusion 51 and the first recess 61. Figure 6 In the illustrated cross-sectional view, surface pressures SP1 and SP2 are applied to the right and left sides of the first convex portion 51. As a modification, surface pressure SP1 or surface pressure SP2 may be zero. As another modification, surface pressure SP1 and surface pressure SP2 may be zero.

[0056] In addition, in the gap GP( Figure 6 ), a fluid (typically air) can flow when the power semiconductor device 101 is operating. This promotes heat dissipation from the heat sink 2. This effect is particularly significant when forced air cooling using a fan or the like is applied.

[0057] In addition, the processing state can be checked by observing the gap GP during or after the heat sink caulking process. For example, the area of ​​the gap GP in the in-plane direction perpendicular to the extension direction of the second recess 62 can be observed. Such observation can be performed, for example, by measuring the projection area of ​​light passing through the gap GP. The state of the heat sink caulking process can be automatically checked by an automatic inspection device having a mechanism for performing such measurement.

[0058] Figure 7 as well as Figure 8 The diagrams are partial cross-sectional views schematically showing states immediately before and immediately after a caulking step in a method for manufacturing a power semiconductor device according to a comparative example. Fig. 9 as well as Fig.10 1 and 2 are partial cross-sectional views schematically showing the states just before and just after the caulking process in the method for manufacturing the power semiconductor device 101 of the first embodiment. Figure 7 and Figure 8 ) is the same as that of the first embodiment. Fig. 9 and Fig.10 ) is different, the comparative example ( Figure 7 and Figure 8 ) has the second concave portion 62 but does not have the second convex portion 52 ( Fig. 9 and Fig.10 : this embodiment).

[0059] In the comparative example ( Figure 7 and Figure 8 ), if the caulking process is started when the positional offset between the heat sink base 14Z and the module base 10 is so large that it cannot be ignored, the module base 10 needs to be plastically deformed in such a way that the first recess 61 is further expanded compared to a case where there is substantially no positional offset. At this time, since the interior of the second recess 62 is completely hollow, the second recess 62 can be shrunk relatively freely in such a way as to absorb the expansion of the first recess 61. Therefore, even if there is a certain degree of positional offset, the necessary load in the caulking process hardly increases. On the other hand, due to the reduction of the second recess 62, the surface pressure between the first convex portion 51 and the first recess 61 is reduced. As a result, there is a possibility that the strength of the caulking joint will be reduced and the thermal contact resistance in the caulking joint will be increased.

[0060] On the other hand, in the present embodiment 1 ( Fig. 9 and Fig.10 ) is performed, the second protrusion 52 is provided on the heat sink base 14. Fig. 9), at least one of the following first and second conditions is satisfied. As the first condition, the height H52B of the second convex portion 52 is smaller than the depth H62B of the second concave portion 62. As the second condition, the width W52B of the end of the second convex portion 52 is smaller than the width W62B of the bottom of the second concave portion 62.

[0061] In this embodiment 1 ( Fig. 9 and Fig.10 ), if the caulking process is started when the positional offset between the heat sink base 14 and the module base 10 is so large that it cannot be ignored, the module base 10 needs to be plastically deformed in a manner that the first recess 61 is further enlarged, compared with the case where there is substantially no positional offset. At this time, since a second convex portion 52 that is smaller than the second recess 62 is inserted into the interior of the second recess 62, as the second recess 62 shrinks in a manner that absorbs the expansion of the first recess 61, the contact between the second recess 62 and the second convex portion 52 deepens, and the surface pressure between them increases. As the second recess 62 shrinks, the surface pressure between the first convex portion 51 and the first recess 61 decreases. This leads to a decrease in the strength of the caulking joint and an increase in the thermal contact resistance in the caulking joint. On the other hand, as described above, the contact between the second recess 62 and the second convex portion 52 deepens, and the surface pressure between them increases, which leads to an increase in the strength of the caulking joint and a decrease in the thermal contact resistance in the caulking joint. Therefore, it is possible to suppress a decrease in the strength of caulking and an increase in the thermal contact resistance in caulking, which are concerns in the comparative example.

[0062] According to the first embodiment, the first convex portion 51 has a tip ( Figure 1 ), and the second convex portion 52 has an end TE ( Figure 6). Thus, in the caulking process in the manufacture of the power semiconductor device 101, the caulking process of the first convex portion 51 and the first concave portion 61 can be started before the caulking process of the second convex portion 52 and the second concave portion 62. At this time, due to the manufacturing deviation of at least one of the positional offset and the dimensional error, it is sometimes difficult to perform the caulking process of the first convex portion 51 and the first concave portion 61. In this case, if the caulking process is continued, the surface pressure between the first convex portion 51 and the first concave portion 61 increases, thereby causing plastic deformation such that the second concave portion 62 is reduced. By this plastic deformation, the increase in the surface pressure between the first convex portion 51 and the first concave portion 61 can be suppressed. Therefore, it is possible to avoid an excessive increase in the necessary load for the caulking process. On the other hand, the excessive reduction of the second concave portion 62 is prevented by being hindered by the second convex portion 52. Therefore, it is possible to avoid the surface pressure between the first convex portion 51 and the first concave portion 61 being too small. Therefore, it is possible to suppress the decrease in the strength of the caulking joint and the increase in the thermal contact resistance in the caulking joint caused by the excessively small surface pressure between the first protrusion 51 and the first recess 61. Based on the above, it is possible to suppress the increase in the necessary load for the caulking process caused by manufacturing deviation, and it is also possible to suppress the decrease in the strength of the caulking joint and the increase in the thermal contact resistance in the caulking joint.

[0063] The above-mentioned effects make it possible to increase the positional deviation allowed during the heat sink caulking process. This can improve the productivity of the power semiconductor device. In addition, a simpler tool can be used as a tool for the heat sink caulking process.

[0064] In addition, a large load required for the caulking process may sometimes reduce the productivity of the power semiconductor device or reduce the reliability due to damage to the components of the power semiconductor device. Phenomena that lead to reduced reliability include damage to the semiconductor element 5 (semiconductor chip), cracking of the semiconductor element 5, changes in the characteristics of the semiconductor element 5, cracking of the resin sealing portion 4, reduction in the insulation withstand voltage of the power semiconductor device 101, or peeling between components of the power semiconductor device 101. As described above, by suppressing the necessary load, productivity can be improved or reliability can be improved. From another point of view, as described above, since the necessary load is suppressed, the positional deviation of the components being caulked can be further allowed. As a result, the productivity of the power semiconductor device can be improved.

[0065] If the second convex portion 52 and the second concave portion 62 are in contact with each other as a result of the plastic deformation of the second concave portion 62, this also helps to suppress the increase in thermal contact resistance. In addition, if the surface pressure is applied between the second convex portion 52 and the second concave portion 62, this also helps to suppress the decrease in bonding strength.

[0066] In addition, the surface of the heat sink 15 may be embossed to impart tiny depressions. The heat sink 15 may be produced by a stamping process using a mold. If the embossing process is performed during the stamping process, the increase in the cost for the embossing process can be largely avoided. The heat dissipation area is increased by the embossing process, thereby improving the heat dissipation performance. In addition, in the case of stacking the heat sink 15 as a component used in the manufacture of the power semiconductor device 101, if the heat sink 15 is embossed, the contact area between the heat sink fins 15 is reduced, and thus the surface friction between the heat sink fins 15 is reduced. By reducing the surface friction, the production equipment for the fin calendering process can be simplified and the production cycle can be shortened, thereby improving productivity. Furthermore, if the heat sink fins 15 are embossed, the embossed portions 11 of the heat sink base 14 penetrate deeper into the embossed portions of the heat sink fins 15 than the portions of the heat sink fins 15 that are not embossed, thereby exerting an anchoring effect. As a result, the thickness direction ( Figure 1 and Figure 2 As a result, the vertical tensile strength of the heat dissipation fin 15 after the fin caulking process is improved.

[0067] In particular, when the heat sink fin 15 is harder than the heat sink base 14, the caulking portion 11 of the heat sink base 14 stays along the surface of the heat sink fin 15 and undergoes plastic deformation during the fin caulking process, and it is difficult for it to bite into the inside of the surface. Therefore, by pre-implementing the embossing process, the vertical tensile strength of the heat sink fin after the fin caulking process is particularly improved. On the other hand, when the heat sink base 14 is harder than the heat sink fin 15, the caulking portion 11 of the heat sink base 14 easily bites into the inside of the surface of the heat sink fin 15 during the fin caulking process, thereby exerting an anchoring effect. Therefore, when the heat sink base 14 is harder than the heat sink fin 15, the effect of the embossing process on the heat sink fin 15 is small. Therefore, from the viewpoint of the vertical tensile strength of the heat sink fin 15 after the fin caulking process, it is preferable to perform at least one of the processing of embossing the surface of the heat sink fin 15 and the processing of selecting a material harder than the material of the heat sink fin 15 as the material of the heat sink base 14. For example, when the material of the radiator base 14 is aluminum 6000 series material and the material of the heat sink fin 15 is aluminum 1000 series material, the vertical tensile strength of the heat sink fin 15 is approximately 2.5 to 3.6 times compared to the case where the material of the radiator base 14 and the material of the heat sink fin 15 are both aluminum 1000 series materials.

[0068] However, the material of the heat sink base 14 and the material of the heat sink fins 15 are not limited to aluminum-based materials, and may be different materials from each other. For example, from the viewpoint of heat dissipation capacity, the heat dissipation capacity is improved by making the heat sink fins 15 from a copper-based plate having a higher thermal conductivity than that of an aluminum-based material. In addition, the heat sink unit 2 is manufactured by joining the heat sink base 14 and the heat sink fins 15 prepared separately by caulking, and the processing constraints (aspect ratio) of the die-casting process or the extrusion process when the heat sink base 14 and the heat sink fins 15 are manufactured separately do not become a problem, so the heat sink fins can be designed relatively freely to improve the heat dissipation capacity of the heat sink unit 2.

[0069] Fig.11 It represents the heat sink 2 ( Figure 2 ) is a cross-sectional view of a heat sink 2M of a modified example. In the manufacture of the heat sink 2M, the heat sink base 14M and the heat dissipation fins 15M are initially formed as one body, so there is no need for fin caulking. The heat sink 2M is manufactured, for example, by extrusion, cutting or forging. Fig.12 It represents the heat sink 2 ( Figure 2 ) is a cross-sectional view of a heat sink 2N of a modified example. In the manufacture of the heat sink 2N, the heat sink base 14N and the heat dissipation fins 15N are initially formed as one body, so that the fin caulking process is not required. The heat sink 2N is manufactured by, for example, die casting.

[0070] Fig.13 is a schematic diagram of a power semiconductor device 101 ( Figure 2 ), a cross-sectional view of a state before the module base 10A and the heat sink base 14A are fastened together in a modified example of the present invention. A guide recess 63 is provided in the surface shape (first surface shape) of the back side PO of the module base 10A. The depth of the guide recess 63 is greater than the depth of the first recess 61 and the depth of the second recess 62. In addition, a guide protrusion 53 is provided in the surface shape (second surface shape) of the mounting surface PF of the heat sink base 14A. The depth of the guide protrusion 53 is greater than the depth of the first protrusion 51 and the depth of the second protrusion 52. Fig.13 In the example shown, guide recesses 63 are provided at two locations (left and right in the figure) on the back surface PO of the module base 10A, and guide protrusions 53 are provided at two locations (left and right in the figure) on the mounting surface PF of the heat sink base 14A. Fig.14 is an example Fig.13 A partial cross-sectional view of the module base 10A and the dimensions of the heat sink base 14A are shown.

[0071] When the heat sink caulking process starts, the module base 10A and the heat sink base 14A can be roughly positioned using the guide protrusion 53 and the guide recess 63. In addition, as the caulking process proceeds, the guide protrusion 53 slides in the guide recess 63, so that the positional deviation can be corrected to a certain extent. Due to this effect, the positional deviation allowed during the heat sink caulking process becomes larger. As a result, the productivity of the power semiconductor device can be improved. In addition, as an auxiliary tool for the heat sink caulking process, a simpler auxiliary tool can be used.

[0072] In the heat sink caulking process, as described above, the surface pressure between the second concave portion 62 and the second convex portion 52 increases as the second concave portion 62 is reduced, and the load required for the caulking process increases to a certain extent. The degree of increase can be appropriately controlled by adjusting the number and size of the second convex portion 52 and the second concave portion 62. Fig.15 and Fig.16 The following are the modified examples under this viewpoint. Fig.15 In FIG. 5 , the module base 10B has only one second recess 62, and the heat sink base 14B has only one second protrusion 52. Fig.16 In the embodiment, the module base 10C has the second recessed portions 62 at alternate locations between the first recessed portions 61 , and the heat sink base 14B has the second convex portions 52 at alternate locations between the first convex portions 51 .

[0073] Fig.17 is a schematic diagram of a power semiconductor device 101 ( Figure 2 ) is a cross-sectional view of a state before the module base 10 and the heat sink base 14 are caulked and joined to each other. Figure 2 ) In contrast, in this modification, the surface shape (first surface shape) of the back surface PO of the module base 10D includes the first convex portion 51 and the second convex portion 52, and the surface shape (second surface shape) of the mounting surface PF of the heat sink base 14D includes the first concave portion 61 and the second concave portion 62. In addition, the features of this modification can also be applied to the above-mentioned modification of the present embodiment 1 and other embodiments described later.

[0074] The above-mentioned heat sink caulking process and fin caulking process can be performed simultaneously. Figure 18 to Figure 20 They are schematic diagrams of a power semiconductor device 101 ( Figure 1 ) in the manufacturing method of the present invention, a cross-sectional view of the state just before the caulking process, during the caulking process, and just after the caulking process is completed. Fig.18 and Fig.19Insert the heat dissipation fin 15 into the fin insertion groove 20 of the heat sink base 14. Then, insert the auxiliary tool 21 into the caulking portion 11 of the heat sink base 14. Then, in a state where the power module part 1 is in contact with the mounting surface PF of the heat sink base 14, a load is applied between the power module part 1 and the auxiliary tool 21 in the thickness direction. In this way, the heat sink caulking process and the fin caulking process are performed simultaneously. This method is suitable for use Figure 3 The floor plan layout is shown.

[0075] Alternatively, the back surface PO of the power module unit 1 may be pressed against the heat sink unit 2M ( 240 ) supported by a tool similar to the tool 23. Fig.11 ) or radiator 2N( Fig.12 ) is applied with a load to the mounting surface PF to perform the heat sink caulking process. The auxiliary tool in this case is different from the auxiliary tool 23, and it is preferred that the tip portion thereof does not have a tapered shape but has a wide flat surface.

[0076] Alternatively, the heat sink caulking process may be performed after the fin caulking process. Fig.21 is a top view for explaining the method, Fig. 22 2 is a cross-sectional view for explaining this method. In this method, a jig 23 is used to support the outer area PR2 around the inner area PR1 where the heat dissipation fins 15 are mounted in the heat dissipation surface PR of the heat sink 2 formed by the fin caulking process. The heat sink caulking process is performed by applying a load in a manner that the back surface PO of the power module 1 is pressed against the mounting surface PF of the heat sink 2 supported by the jig 23. This method is applicable to heat sinks that do not use Figure 3 The floor plan shown in the example (for example, using Figure 4 or Figure 5 The floor plan shown).

[0077] <Implementation method 2>

[0078] Fig.23 1 is a cross-sectional view schematically showing the structure of a power semiconductor device 102 according to the second embodiment. The power semiconductor device 102 includes a heat sink base 14S instead of the power semiconductor device 101 ( Figure 1 ) of the heat sink base 14. The other structures are the same as those of the above-mentioned embodiment 1 ( Figure 1 and Figure 2 ) have roughly the same structure. Fig.24 It roughly indicates Fig.23 The power semiconductor device 102 is shown in a cross-sectional view of a state before the module base 10 and the heat sink base 14S are caulked and joined.

[0079] The heat sink base 14S has an in-plane direction ( Fig.23 and Fig.24 The heat dissipation surface PR ( Fig.23 and Fig.24 The outer side surface PP is arranged to be biased toward the heat dissipation surface PR (in other words, biased toward the lower surface of the heat sink base 14S) in the thickness direction relative to the mounting surface PF. Fig.23 and Fig.24 As described above, in the second embodiment, as a surface opposite to the heat dissipation surface PR, an outer side surface PP is provided in addition to the mounting surface PF. Therefore, in the second embodiment, the outer surface area of ​​the heat dissipation surface PR is larger than the outer surface area of ​​the mounting surface PF.

[0080] The heat sink base 14S can be regarded as having a module mounting portion 14a constituting the mounting surface PF, and a heat diffusion portion 14d constituting the outer side surface PP and the heat dissipation surface PR. The heat diffusion portion 14d is separated from the module base 10 by the module mounting portion 14a. In the in-plane direction, the heat diffusion portion 14d extends to the outside of the module mounting portion 14a. In addition, the boundary ( Fig.23 as well as Fig.24 The dashed lines in the figure may be imaginary.

[0081] The portion of the lead frame 3 protruding from the resin sealing portion 4 is not opposed to the mounting surface PF in the thickness direction, but is opposed to the outer side surface PP at a distance D2. The distance D2 corresponds to the insulation distance between the lead frame 3 and the heat sink base 14S (typically, the distance separated by air). On the other hand, the lead frame 3 and the heat sink base 14 ( Figure 1 :Implementation 1) The insulation distance is equivalent to the distance D1 ( Figure 1 ), which is roughly the same as the thickness of the module base 10. Therefore, in the above-mentioned embodiment 1, in order to increase the insulation distance, it is necessary to increase the thickness of the module base 10. If the thickness of the module base 10 is too large, the productivity of the power semiconductor device is reduced. Specifically, first, the heat capacity of the module base 10 becomes larger, so in the formation process of the resin sealing portion 4 in the manufacture of the power semiconductor device 101, that is, the molding process, the time required to raise the temperature to the process temperature becomes longer, so the productivity is reduced. Second, the mold used in the molding process becomes larger, so the device for molding also becomes larger, thereby reducing productivity. Third, since the mold used in the molding process becomes larger, its heat capacity also becomes larger, so the time required to raise the mold to the process temperature becomes longer, thereby reducing productivity.

[0082] According to the second embodiment, the outer side surface PP is arranged to be closer to the heat dissipation surface PR than the mounting surface PF in the thickness direction. Thus, the distance between the lead frame 3 protruding from the resin sealing portion 4 and the outer side surface PP of the heat sink base 14S opposed thereto in the thickness direction, that is, the insulation distance, can be increased without relying solely on the thickness of the module base 10.

[0083] <Implementation method 3>

[0084] Fig.25 It is a cross-sectional view schematically showing the structure of a power semiconductor device 103 according to the third embodiment. Fig.26 and Fig. 27 It is a cross-sectional view schematically showing steps in a method for manufacturing the power semiconductor device 103 .

[0085] The heat sink base 14P includes: a third recess 64; and a pin part 29, which has an insertion portion inserted into the third recess 64 and a protrusion protruding from the third recess 64. The second protrusion 52 is formed by the protrusion. In addition, the boundary between the third recess 64 and the pin part 29 can be actually observed. The third recess 64 of the heat sink base 14P is composed of a first metal material, and the pin part 29 of the heat sink base 14P is composed of a second metal material. The portion of the heat sink base 14P other than the pin part 29 can be composed of the first metal material. The second metal material can be the same as or different from the first metal material. In the latter case, it is preferred that the second metal material is a material harder than the first metal material, thereby suppressing the plastic deformation of the second protrusion 52 during the heat sink calendering process. Therefore, the increase in the surface pressure between the second recess 62 and the second protrusion 52 caused by the reduction of the second recess 62 can be made more rapid. Therefore, the effect described in embodiment 1 can be further improved. In addition, the structure other than the above is different from the above-mentioned embodiment 1 ( Figure 1 ) have roughly the same structure.

[0086] According to the present embodiment, after the mounting surface PF having the first protrusion 51 is formed (see Fig.26 ), the second protrusion 52 is provided on the mounting surface PF by inserting the pin member 29 (see Fig. 27 ). Thus, when forming the first protrusion 51, it is not necessary to simultaneously form the second protrusion 52. Therefore, it is possible to reduce the difficulty of manufacturing the heat sink base 14P in consideration of the aspect ratio of the mounting surface PF and the like.

[0087] In addition, as a modified example, refer to Fig.17As described above, the second protrusion 52 and the third recess 64 into which it is inserted may be included in the surface shape (first surface shape) of the back surface PO of the module base, instead of being included in the surface shape (second surface shape) of the mounting surface PF of the heat sink base. In this case, the third recess 64 of the module base is made of the first metal material, and the pin component 29 of the module base is made of the second metal material. The portion of the module base other than the pin component 29 may be made of the first metal material. The second metal material may be the same as or different from the first metal material. In the latter case, the second metal material is preferably a harder material than the first metal material.

[0088] <Implementation method 4>

[0089] This embodiment applies the power semiconductor device of at least one of the above-mentioned embodiments 1 to 3 to a power conversion device. The application of the power semiconductor device of embodiments 1 to 3 is not limited to a specific power conversion device. Hereinafter, as embodiments 1 to 3, the case where the power semiconductor device of at least one of embodiments 1 to 3 is applied to a three-phase inverter will be described.

[0090] Fig.28 : is a block diagram showing the configuration of a power conversion system to which the power conversion device according to the present embodiment is applied.

[0091] Fig.28 The power conversion system shown is composed of a power supply 100, a power conversion device 200, and a load 300. The power supply 100 is a DC power supply, and supplies DC power to the power conversion device 200. The power supply 100 can be composed of various power supplies, for example, it can be composed of a DC system, a solar cell, a storage battery, or a rectifier circuit or an AC / DC converter connected to an AC system. In addition, the power supply 100 can also be composed of a DC / DC converter that converts the DC power output from the DC system into a predetermined power.

[0092] The power conversion device 200 is a three-phase inverter connected between the power source 100 and the load 300, converts the direct current supplied from the power source 100 into alternating current, and supplies the alternating current to the load 300. Fig.28 As shown, the power conversion device 200 includes: a main conversion circuit 201, which converts direct current into alternating current and outputs it; and a control circuit 203, which outputs a control signal for controlling the main conversion circuit 201 to the main conversion circuit 201.

[0093] Load 300 is a three-phase motor driven by the AC power supplied from power converter 200. Load 300 is not limited to a specific use, and is used as a motor mounted on various electrical devices, for example, a hybrid vehicle, an electric vehicle, a railway vehicle, an elevator, or an air conditioner.

[0094] The following describes the details of the power conversion device 200. The main conversion circuit 201 includes a switching element and a freewheeling diode (not shown), and the switching element is used to switch, convert the direct current supplied from the power supply 100 into alternating current, and supply it to the load 300. Although there are various structures for the specific circuit structure of the main conversion circuit 201, the main conversion circuit 201 of this embodiment is a 2-level three-phase full-bridge circuit, which can be composed of 6 switching elements and 6 freewheeling diodes connected in anti-parallel with each switching element. Each switching element and each freewheeling diode of the main conversion circuit 201 is composed of a semiconductor module 202 equivalent to a power semiconductor device of at least one of the above-mentioned embodiments 1 to 3. The six switching elements are connected in series to form upper and lower arms, and each upper and lower arm constitutes each phase (U phase, V phase, W phase) of the full-bridge circuit. In addition, the output terminals of each upper and lower arm, that is, the three output terminals of the main conversion circuit 201, are connected to the load 300.

[0095] In addition, the main conversion circuit 201 includes a drive circuit (not shown) for driving each switching element. The drive circuit may be built into the semiconductor module 202 or may be a structure that includes the drive circuit separately from the semiconductor module 202. The drive circuit generates a drive signal for driving the switching element of the main conversion circuit 201 and supplies it to the control electrode of the switching element of the main conversion circuit 201. Specifically, according to the control signal from the control circuit 203 described later, a drive signal for turning the switching element into an on state and a drive signal for turning the switching element into an off state are output to the control electrode of each switching element. When the switching element is maintained in an on state, the drive signal is a voltage signal (on signal) above the threshold voltage of the switching element, and when the switching element is maintained in an off state, the drive signal becomes a voltage signal (off signal) below the threshold voltage of the switching element.

[0096] The control circuit 203 controls the switch elements of the main conversion circuit 201 to supply the desired power to the load 300. Specifically, the time (on time) at which each switch element of the main conversion circuit 201 should be in the on state is calculated according to the power to be supplied to the load 300. For example, the main conversion circuit 201 can be controlled by PWM control that modulates the on time of the switch element according to the voltage to be output. Then, a control instruction (control signal) is output to the drive circuit of the main conversion circuit 201, so that at each moment, the on signal is output to the switch element that should be in the on state, and the off signal is output to the switch element that should be in the off state. The drive circuit outputs the on signal or the off signal as a drive signal to the control electrode of each switch element according to the control signal.

[0097] In the power converter of this embodiment, at least one of the power semiconductor devices of Embodiments 1 to 3 is applied as a power semiconductor device including at least one of the switching element and the freewheeling diode of the main conversion circuit 201. This can improve productivity and reliability of the power converter.

[0098] In this embodiment, an example of applying the power semiconductor device of at least one of Embodiments 1 to 3 to a 2-level three-phase inverter is described, but the application of the power semiconductor device of at least one of Embodiments 1 to 3 is not limited to this, and can be applied to various power conversion devices. In this embodiment, it is a 2-level power conversion device, but it can also be a 3-level or multi-level power conversion device. When supplying power to a single-phase load, the power semiconductor device of at least one of Embodiments 1 to 3 can also be applied to a single-phase inverter. In addition, when supplying power to a DC load, etc., the power semiconductor device of at least one of Embodiments 1 to 3 can also be applied to a DC / DC converter or an AC / DC converter.

[0099] In addition, the power conversion device using the power semiconductor device of at least any one of embodiments 1 to 3 is not limited to the case where the load is an electric motor. For example, it can also be used as a power supply device for an electric discharge machine, a laser processing machine, an induction heating cooker, or a contactless power supply system. It can also be used as a power conditioner for a solar power generation system, a power storage system, etc.

[0100] In addition, the various embodiments can be freely combined, or the various embodiments can be appropriately modified or omitted.

[0101] <Notes>

[0102] Hereinafter, each aspect of the present disclosure will be collectively described as a supplementary note.

[0103] (Note 1)

[0104] A power semiconductor device (101-103, 101V), comprising:

[0105] A module base (10, 10A-10D) having a mounting surface (PM) and a back surface (PO) opposite to the mounting surface (PM) in a thickness direction;

[0106] A semiconductor element (5) mounted on the mounting surface (PM) of the module base (10, 10A-10D);

[0107] a resin sealing portion (4) that seals the semiconductor element (5) on the mounting surface (PM) of the module base (10, 10A to 10D); and

[0108] A heat sink base (14, 14A to 14D, 14M, 14N, 14P, 14S) having a mounting surface (PF) mounted on the back surface (PO) of the module base (10, 10A to 10D), and a heat dissipation surface (PR) opposite to the mounting surface (PF) in the thickness direction,

[0109] The first surface shape of the back surface (PO) provided on the module base (10, 10A to 10D) and the second surface shape of the mounting surface (PF) of the heat sink base (14, 14A to 14D, 14M, 14N, 14P, 14S) are mutually fitted, thereby the back surface (PO) of the module base (10, 10A to 10D) and the mounting surface (PF) of the heat sink base (14, 14A to 14D, 14M, 14N, 14P, 14S) are fixed to each other,

[0110] One of the first surface shape and the second surface shape includes a first convex portion (51) and a second convex portion (52), and the other includes a first concave portion (61) engaged with the first convex portion (51) and a second concave portion (62) engaged with the second convex portion (52).

[0111] The first convex portion (51) has a distal end in contact with the first concave portion (61), and the second convex portion (52) has a distal end (TE) separated from the second concave portion (62).

[0112] (Note 2)

[0113] The power semiconductor device (101-103, 101V) according to Supplementary Note 1, wherein:

[0114] In a cross-sectional view parallel to the thickness direction, a height (H52) of the second convex portion is greater than or equal to 0.5 mm, and a width (W52) of the second convex portion is greater than or equal to 65% and less than 100% of a width (W62) of the second concave portion.

[0115] (Note 3)

[0116] The power semiconductor device (101 to 103, 101V) according to Supplement 1 or 2, wherein:

[0117] In a cross-sectional view parallel to the thickness direction, no gap is formed between the first convex portion (51) and the first concave portion (61), or a gap smaller than a gap (GP) between the second convex portion (52) and the second concave portion (62) is formed.

[0118] (Note 4)

[0119] The power semiconductor device (101-103, 101V) according to any one of Supplementary Notes 1 to 3, wherein:

[0120] In a cross-sectional view parallel to the thickness direction, no gap is formed between the first convex portion (51) and the first concave portion (61), or a gap having an area less than 50% of the area of ​​the first concave portion (61) is formed.

[0121] (Note 5)

[0122] The power semiconductor device (101-103, 101V) according to any one of Supplementary Notes 1 to 4, wherein:

[0123] Surface pressure is at least partially applied between the first convex portion (51) and the first concave portion (61).

[0124] (Note 6)

[0125] The power semiconductor device (101-103, 101V) according to any one of Supplementary Notes 1 to 5, wherein:

[0126] No surface pressure is applied between the second convex portion (52) and the second concave portion (62), or a maximum surface pressure lower than a maximum surface pressure between the first convex portion (51) and the first concave portion (61) is applied.

[0127] (Note 7)

[0128] The power semiconductor device (101-103, 101V) according to any one of Supplementary Notes 1 to 6, wherein:

[0129] Surface pressure is applied at least partially between the second convex portion (52) and the second concave portion (62).

[0130] (Note 8)

[0131] A power semiconductor device (102) according to any one of Supplementary Notes 1 to 7, wherein:

[0132] The heat sink base (14S) has an outer side surface (PP) arranged outside the mounting surface (PF) in an in-plane direction perpendicular to the thickness direction and opposite to the heat dissipation surface (PR).

[0133] The outer side surface (PP) is arranged to be closer to the heat dissipation surface (PR) than the mounting surface (PF) in the thickness direction.

[0134] (Note 9)

[0135] The power semiconductor device (101-103, 101V) according to any one of Supplementary Notes 1 to 8, wherein:

[0136] The planar layout of the recess group (60) including the first recess (61) and the second recess (62) perpendicular to the thickness direction includes a plurality of patterns extending along a first direction and arranged at intervals in a second direction perpendicular to the first direction.

[0137] (Note 10)

[0138] The power semiconductor device (101-103, 101V) according to any one of Supplementary Notes 1 to 8, wherein:

[0139] The planar layout perpendicular to the thickness direction of the recess group (60) including the first recess (61) and the second recess (62) includes: a plurality of patterns (P1) extending respectively along a first direction and arranged at intervals in a second direction perpendicular to the first direction; and at least one pattern (P2) extending along a third direction different from the first direction.

[0140] (Note 11)

[0141] A power semiconductor device (103) according to any one of Supplementary Notes 1 to 10, wherein:

[0142] The module base or the heat sink base includes: a third recess (64); and a component (29) having an insertion portion inserted into the third recess (64) and a protrusion portion protruding from the third recess (64), wherein the second protrusion (52) is constituted by the protrusion portion.

[0143] (Note 12)

[0144] A power conversion device (200) comprising:

[0145] A main conversion circuit (201) comprising a power semiconductor device (101-103, 101V) according to any one of Supplementary Notes 1 to 11, converting input power and outputting the converted power; and

[0146] A control circuit (203) outputs a control signal for controlling the main conversion circuit (201) to the main conversion circuit (201).

[0147] Description of symbols

[0148] 1: Power module part; 2, 2M, 2N: Heat sink part; 3: Lead frame; 4: Resin sealing part; 5: Semiconductor element; 10, 10A~10D: Module base; 14, 14A~14D, 14M, 14N, 14P, 14S: Heat sink base; 15, 15M, 15N: Heat dissipation fins; 29: Pin component; 51: First protrusion; 52: Second protrusion; 60: Recess group; 61: First recess; 62: Second recess; 64: Third recess; 101~103: Power semiconductor device; 200: Power conversion device; 201: Main conversion circuit; 203: Control circuit; PF: Mounting surface; PM: Assembly surface; PO: Back surface; PP: Outer side surface; PR: Heat dissipation surface.

Claims

1. A power semiconductor device comprising: A module base having a mounting surface and a back surface opposite to the mounting surface in a thickness direction; a semiconductor element mounted on the mounting surface of the module base; a resin sealing portion that seals the semiconductor element on the mounting surface of the module base; as well as a heat sink base having a mounting surface mounted on the back surface of the module base and a heat dissipation surface opposite to the mounting surface in the thickness direction, The first surface shape of the back side of the module base and the second surface shape of the mounting surface of the radiator base fit together, thereby fixing the back side of the module base and the mounting surface of the radiator base to each other. One of the first surface shape and the second surface shape includes a first convex portion and a second convex portion, and the other includes a first concave portion that fits with the first convex portion and a second concave portion that fits with the second convex portion. The first convex portion has a distal end in contact with the first concave portion, and the second convex portion has a distal end separated from the second concave portion.

2. The power semiconductor device according to claim 1, wherein: In a cross-sectional view parallel to the thickness direction, the height of the second convex portion is 0.5 mm or more, and the width of the second convex portion is 65% or more and less than 100% of the width of the second concave portion.

3. The power semiconductor device according to claim 1 or 2, wherein: In a cross-sectional view parallel to the thickness direction, no gap is formed between the first convex portion and the first concave portion, or a gap smaller than a gap between the second convex portion and the second concave portion is formed.

4. The power semiconductor device according to claim 1 or 2, wherein: In a cross-sectional view parallel to the thickness direction, no gap is formed between the first convex portion and the first concave portion, or a gap having an area that is 50% or less of an area of ​​the first concave portion is formed.

5. The power semiconductor device according to claim 1 or 2, wherein: A surface pressure is applied at least partially between the first convex portion and the first concave portion.

6. The power semiconductor device according to claim 1 or 2, wherein: No surface pressure is applied between the second convex portion and the second concave portion, or a maximum surface pressure lower than a maximum surface pressure between the first convex portion and the first concave portion is applied.

7. The power semiconductor device according to claim 1 or 2, wherein: A surface pressure is applied at least partially between the second convex portion and the second concave portion.

8. The power semiconductor device according to claim 1 or 2, wherein: The heat sink base has an outer side surface which is arranged outside the mounting surface in an in-plane direction perpendicular to the thickness direction and is opposite to the heat dissipation surface. The outer side surface is arranged to be closer to the heat dissipation surface than the mounting surface in the thickness direction.

9. The power semiconductor device according to claim 1 or 2, wherein: The planar layout of the recess group including the first recess and the second recess, which is perpendicular to the thickness direction, includes a plurality of patterns that extend along a first direction and are arranged at intervals in a second direction perpendicular to the first direction.

10. The power semiconductor device according to claim 1 or 2, wherein: A planar layout of a recess group including the first recess and the second recess, which is perpendicular to the thickness direction, includes: a plurality of patterns extending along a first direction and arranged at intervals in a second direction perpendicular to the first direction; and at least one pattern extending along a third direction different from the first direction.

11. The power semiconductor device according to claim 1 or 2, wherein: The module base or the heat sink base includes: a third recess; and a member having an insertion portion inserted into the third recess and a protrusion portion protruding from the third recess, wherein the second protrusion is constituted by the protrusion portion.

12. A power conversion device comprising: A main conversion circuit, comprising the power semiconductor device according to claim 1 or 2, which converts input power and outputs the converted power; and A control circuit outputs a control signal for controlling the main conversion circuit to the main conversion circuit.

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