Power module, power module manufacturing method, and power conversion device

Abstract

This power module comprises: a semiconductor chip; a lead frame with the semiconductor chip mounted on one surface thereof; a module base with the lead frame disposed on one surface thereof; a main terminal, which is a portion of the lead frame; a mold part for sealing the semiconductor chip, the lead frame, and the module base such that the main terminal is exposed; a heat sink having a base part integrated with the other surface of the module base exposed from the mold part, and a plurality of heat dissipating fins protruding to the opposite side of the module base of the base part; a bus bar connected to a first main surface of the main terminal or a second main surface on the side opposite from the first main surface; and a terminal block that is fixed on the base part of the heat sink and disposed between the main terminal or the bus bar and the base part. The second main surface of the main terminal faces the heat sink, and the first main surface of the main terminal faces the side opposite from the heat sink.

Description

[Technical field]

[0001] The present disclosure relates to a power module, a method for manufacturing a power module, and a power conversion device. [Background technology]

[0002] For example, Patent Document 1 discloses a heat sink-integrated power module having a power module section, a fin base, and heat dissipation fins. The power module section includes a module base, a power semiconductor element mounted on the module base, and a molded resin that seals the power semiconductor element. The fin base includes a heat dissipation diffusion section to which the heat dissipation fins are attached, and a base section formed on the heat dissipation diffusion section and to which the module base is joined. The module base is provided with a first uneven section, and the base section is provided with a second uneven section that fits with the first uneven section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 675904 Summary of the Invention [Problem to be solved by the invention]

[0004] When the current flowing through the power module increases, the current flowing through the main terminal also increases, causing a large rise in temperature in the main terminal. In order to suppress the temperature rise in the main terminal, it is widely and commonly practiced to connect a bus bar (external terminal) to the main terminal.

[0005] However, the technology described in Patent Document 1 does not include a structure for connecting a bus bar to the main terminal, and so there is a concern that the temperature rise of the main terminal will be large.

[0006] Therefore, an object of the present disclosure is to provide a technique capable of suppressing a temperature rise in a main terminal by connecting an external terminal to the main terminal in a power module with an integrated heat sink. [Means for solving the problem]

[0007] A power module according to the present disclosure includes a semiconductor element, a frame having the semiconductor element mounted on one surface thereof, a module base having the frame disposed on one surface thereof, a main terminal which is a part of the frame, a molded portion which seals the semiconductor element, the frame, and the module base so that the main terminal is exposed, a base portion which is integrated with the other surface of the module base exposed from the molded portion, and a heat sink having a plurality of heat dissipation fins which protrude from the base portion on the side opposite to the module base, and an external terminal connected to a first main surface of the main terminal or a second main surface opposite to the first main surface; before Base part The outer periphery of the surface on the module base side and the main terminal or the external terminal and the base portion are fixed on the On the outer periphery of the surface on the module base side and a displacement control structural member disposed between the heat sink and the second main surface of the main terminal faces the heat sink, and the first main surface of the main terminal faces away from the heat sink. Effect of the Invention

[0008] According to the present disclosure, since terminal forming processing is not required on the first and second main surfaces of the main terminal, the areas of the first and second main surfaces can be increased. As a result, in a power module with an integrated heat sink, an external terminal can be connected to the main terminal, making it possible to suppress a temperature rise in the main terminal.

[0009] The objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings. [Brief description of the drawings]

[0010] [Figure 1]FIG. 1 is a cross-sectional view of a power module according to a first embodiment. [Diagram 2] FIG. 2 is a top view of the power module according to the first embodiment. [Diagram 3] FIG. 4 is a top view of a power module according to a modified example of the first embodiment. [Figure 4] 10 is a cross-sectional view showing a connection between a main terminal and a bus bar included in a power module according to a modified example of the first embodiment. FIG. [Diagram 5] FIG. 4 is a top view of a power module according to a modified example of the first embodiment. [Figure 6] FIG. 4 is a top view of a power module according to a modified example of the first embodiment. [Figure 7] 11 is a cross-sectional view showing a connection by screw fastening between a main terminal and a bus bar provided in a power module according to a modified example of the first embodiment. FIG. [Figure 8] 13 is a top view showing connection by screw fastening between a main terminal and a bus bar provided in the power module according to a modified example of the first embodiment. FIG. [Figure 9] 11 is a cross-sectional view showing a connection by screw fastening between a main terminal and a bus bar with nuts provided in a power module according to a modified example of the first embodiment. FIG. [Figure 10] 10 is a cross-sectional view showing a connection by screw fastening between a nut-equipped main terminal and a bus bar provided in a power module according to a modified example of the first embodiment. FIG. [Figure 11] 10 is a cross-sectional view showing a connection by screw fastening between a main terminal on which a screw fastening auxiliary member provided in a power module according to a modification of the first embodiment is disposed and a bus bar. FIG. [Figure 12] 10 is a cross-sectional view showing the positional relationship between a main terminal and a screw fastening auxiliary member included in a power module according to a modified example of the first embodiment. FIG. [Figure 13] 10 is a cross-sectional view showing the positional relationship between a main terminal and an elastic screw-fastening auxiliary member included in a power module according to a modified example of the first embodiment. FIG. [Figure 14] 10 is a cross-sectional view showing a connection by soldering between a main terminal and a bus bar included in a power module according to a modified example of the first embodiment. FIG. [Figure 15]11 is a cross-sectional view showing a connection by welding between a main terminal and a bus bar included in a power module according to a modified example of the first embodiment. FIG. [Figure 16] 10 is a cross-sectional view showing a connection by crimping between a main terminal and a bus bar provided in a power module according to a modified example of the first embodiment. FIG. [Figure 17] FIG. 4 is a cross-sectional view of a power module according to a modified example of the first embodiment. [Figure 18] FIG. 4 is a cross-sectional view of a power module according to a modified example of the first embodiment. [Figure 19] FIG. 4 is a cross-sectional view of a power module according to a modified example of the first embodiment. [Figure 20] FIG. 11 is a cross-sectional view of a power module according to a second embodiment. [Figure 21] FIG. 11 is a top view of a power module according to a second embodiment. [Figure 22] 11 is a cross-sectional view showing a connection by screw fastening between a terminal block and a heat sink included in a power module according to a second embodiment. FIG. [Figure 23] 13 is a cross-sectional view showing a connection by soldering between a terminal block and a heat sink included in a power module according to a modified example of the second embodiment. FIG. [Figure 24] 13 is a cross-sectional view showing a connection by welding between a terminal block and a heat sink included in a power module according to a modified example of the second embodiment. FIG. [Diagram 25] 13 is a cross-sectional view showing a connection by crimping between a terminal block and a heat sink included in a power module according to a modified example of the second embodiment. FIG. [Figure 26] 11 is a cross-sectional view showing a connection by screw fastening between a main terminal and a bus bar provided in a power module according to a modified example of the second embodiment. FIG. [Figure 27] 11 is a cross-sectional view showing a connection by soldering between a main terminal and a bus bar included in a power module according to a modified example of the second embodiment. FIG. [Figure 28] 11 is a cross-sectional view showing a connection by welding between a main terminal and a bus bar included in a power module according to a modified example of the second embodiment. FIG. [Figure 29]11 is a cross-sectional view showing a connection by crimping between a main terminal and a bus bar provided in a power module according to a modified example of the second embodiment. FIG. [Diagram 30] 13 is a cross-sectional view showing a connection by screw fastening between a main terminal and a bus bar using a main terminal with nuts or a bus bar with nuts provided in a power module according to a modified example of the second embodiment. FIG. [Diagram 31] 13 is a cross-sectional view showing the arrangement of a terminal block having a positioning structure included in a power module according to a modified example of the second embodiment. FIG. [Diagram 32] 13A to 13C are a cross-sectional view, a side view, and a top view showing the arrangement of a terminal block having a positioning structure provided in a power module according to a modified example of the second embodiment. [Diagram 33] 13 is a cross-sectional view showing a clearance between a main terminal and a terminal block included in a power module according to a modified example of the second embodiment. FIG. [Diagram 34] 13 is a cross-sectional view showing connection by screw fastening between a main terminal and a bus bar when a clearance exists between the main terminal and the terminal block included in the power module according to the modified example of the second embodiment. FIG. [Diagram 35] 13 is a cross-sectional view showing the clearance between the main terminal and the terminal block when a terminal block with elastic function provided in the power module according to the modified example of the second embodiment is used. FIG. [Diagram 36] 11 is a cross-sectional view showing a connection by screw fastening between a main terminal, a bus bar, and a terminal block provided in a power module according to a third embodiment. FIG. [Figure 37] 11 is a cross-sectional view showing a connection by soldering of a main terminal, a bus bar, and a terminal block included in a power module according to a third embodiment. FIG. [Figure 38] 11 is a cross-sectional view showing a connection by welding between a main terminal, a bus bar, and a terminal block included in a power module according to a third embodiment. FIG. [Figure 39] 11 is a cross-sectional view showing a connection by crimping between a main terminal, a bus bar, and a terminal block provided in a power module according to a third embodiment. FIG. [Diagram 40] 11 is a cross-sectional view showing a terminal block having a nut-fall-out prevention metal member provided in a power module according to embodiment 3. FIG. [Diagram 41] FIG. 11 is a cross-sectional view showing a state in which a power module according to a third embodiment is used as a product. [Diagram 42] FIG. 1 is a cross-sectional view showing a typical power module during product use. [Diagram 43] 11 is a cross-sectional view showing a clearance between a main terminal and a terminal block included in a power module according to a third embodiment. FIG. [Diagram 44] 11 is a cross-sectional view showing connection by screw fastening of a main terminal, a bus bar, and a terminal block when a clearance exists between the main terminal and the terminal block included in the power module according to the third embodiment. FIG. [Diagram 45] 13 is a cross-sectional view showing the clearance between a main terminal and a terminal block when a terminal block with an elastic function provided in the power module according to the third embodiment is used. FIG. [Figure 46] FIG. 11 is a block diagram showing a configuration of a power conversion system to which a power conversion device according to a fourth embodiment is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Embodiment 1> The first embodiment will be described below with reference to the drawings. Fig. 1 is a cross-sectional view of a power module 202 according to the first embodiment. Fig. 2 is a top view of the power module 202 according to the first embodiment.

[0012] 1 and 2, the power module 202 is a heat sink integrated power module, and includes a power module section 9 and a heat sink 13. The power module section 9 includes a plurality of semiconductor chips 1 (semiconductor elements), a lead frame 3 (frame), an insulating sheet 4, a module base 5, a molded section 8, and a plurality of bus bars 10 (external terminals).

[0013] A plurality of semiconductor chips 1 are mounted on the upper surface (one surface) of a lead frame 3. The lead frame 3 is arranged via an insulating sheet 4 attached to the upper surface (one surface) of a module base 5. The molded portion 8 is made of mold resin, and seals the semiconductor chips 1, lead frame 3, insulating sheet 4, and module base 5 so that the main terminals 7, which are part of the lead frame 3, and the lower surface (the other surface) of the module base 5 are exposed.

[0014] The heat sink 13 has a base portion 11 integrated with the lower surface (the other surface) of the module base 5, and a plurality of heat dissipation fins 12 protruding downward from the base portion 11 (the side opposite to the module base 5). A plurality of concave fitting portions 5a are provided on the lower surface (the other surface) of the module base 5. A plurality of convex fitted portions 11a that can be fitted with the fitting portions 5a are provided on the upper surface (the surface on the module base 5 side) of the base portion 11 except for the outer periphery. The module base 5 and the heat sink 13 are integrated by fitting the fitting portions 5a with the fitted portions 11a. The fitting portions 5a and the fitted portions 11a may be provided continuously or discontinuously in the depth direction of the module base 5 and the base portion 11, respectively.

[0015] After the molding, molding is performed to form terminals, thereby forming the control terminals 6 and the main terminals 7 that are parts of the lead frame 3. However, molding to form the terminals is not essential and can be omitted.

[0016] Next, the main terminal 7 and the control terminal 6 will be described. The main terminal 7 and the control terminal 6 are part of the lead frame 3, and are connected to the semiconductor chip 1 inside the molded portion 8 by a wiring member (not shown) such as an aluminum wire. However, the wiring member does not necessarily have to be an aluminum wire, and may be electrically connected by, for example, a metal wire such as a copper wire, or a metal plate using a joining member such as solder. The main terminal 7 and the control terminal 6 are integrated by molding while being exposed from the molded portion 8.

[0017] The multiple (four) main terminals 7 extend in a left-right direction (first direction) that is parallel to the base portion 11 of the heat sink 13, and are exposed from the molded portion 8. Specifically, two of the main terminals 7 are formed linearly so as to extend leftward from the left end of the molded portion 8, and the remaining two main terminals 7 are formed linearly so as to extend rightward from the right end of the molded portion 8. A second main surface (lower surface) opposite to the first main surface (upper surface) of each of the main terminals 7 faces the heat sink 13, and the first main surface (upper surface) of each of the main terminals 7 faces the opposite side to the heat sink 13 (upward).

[0018] Here, when a large current flows through the power module, the thickness of the lead frame 3 including the main terminals 7 and the control terminals 6 is often increased from the viewpoint of current density. For this reason, when attempting to bend a thick lead frame 3 by terminal formation processing, the press tonnage becomes large, raising concerns about an increase in the size of the equipment and a decrease in productivity.

[0019] In the first embodiment, as described above, the second main surface (lower surface) opposite to the first main surface (upper surface) of the main terminal 7 faces the heat sink 13, and the first main surface (upper surface) of the main terminal 7 faces the opposite side (upward) from the heat sink 13. In other words, by forming the main terminal 7 having a large terminal cross-sectional area so as to extend horizontally relative to the molded portion 8, terminal formation processing is not required on the first and second main surfaces of the main terminal 7, and the areas of the first and second main surfaces can be increased. Also, since only the control terminal 6 having a small terminal cross-sectional area is formed and processed as necessary, there is no need to increase the size of the equipment, improving productivity.

[0020] Furthermore, by connecting the bus bar 10 to the main terminal 7, it is no longer necessary to increase the length of the main terminal 7 from the viewpoint of heat dissipation, and the length can be shortened. The area of ​​the lead frame 3 including the main terminal 7 can be reduced by the amount of the shortened length of the main terminal 7. This makes it possible to take out a number of shapes from one lead frame (multiple pieces), and it is possible to improve productivity. Alternatively, the area of ​​the lead frame 3 inside the power module 202 can be increased by the amount of the shortened length of the main terminal 7 while keeping the area of ​​the lead frame 3 including the main terminal 7 the same. This improves the degree of freedom in designing the arrangement of the semiconductor chip 1 and the electrical wiring, and it is possible to improve heat dissipation.

[0021] <Modification of the first embodiment> Next, a description will be given of a modification of embodiment 1. Figures 3(a) and (b) are top views of a power module 202 according to a modification of embodiment 1.

[0022] As shown in FIG. 3(a), the main terminal 7 may be L-shaped when viewed from above, or as shown in FIG. 3(b), the main terminal 7 may be U-shaped when viewed from above. However, the shape of the main terminal 7 is not limited to this and can be freely designed. By using such a shape, it is possible to reduce the stress applied to the interface between the main terminal 7 and the molded portion 8 when the main terminal 7 is connected to the bus bar 10. Furthermore, it is also possible to reduce the stress applied to the interface between the main terminal 7 and the molded portion 8 when vibrations occur during use of the product, thereby improving the vibration resistance of the product.

[0023] FIG. 4 is a cross-sectional view showing a connection between a main terminal 7 and a bus bar 10 included in a power module 202 according to a modification of the first embodiment. As shown in FIG. 4, the main terminal 7 may have a crank shape in a cross-sectional view. Specifically, the main terminal 7 has a first parallel portion 7a exposed from the molded portion 8 in a first direction parallel to the base portion 11 of the heat sink 13, a first vertical portion 7b extending from the first parallel portion 7a in a second direction vertical to the first parallel portion 7a, and a second parallel portion 7c extending from the first vertical portion 7b in the first direction. The bus bar 10 is connected to a first main surface of the second parallel portion 7c of the main terminal 7.

[0024] As shown in Fig. 4, by bending the main terminal 7 during the terminal formation process, the bent portion has an elastic function, so that it is possible to reduce the stress applied to the interface between the main terminal 7 and the molded portion 8 when the main terminal 7 is connected to the busbar 10. Similarly, it is possible to reduce the stress applied to the interface between the main terminal 7 and the molded portion 8 when vibration occurs during use of the product, so that the vibration resistance of the product is improved. Note that although the shape of the main terminal 7 shown in Fig. 4 requires bending, the second parallel portion 7c extends in the horizontal direction, so that, for example, one busbar 10 with a large area can be stably connected to two main terminals 7.

[0025] Here, as shown in FIG. 2, the power module 202 according to the first embodiment has a structure in which the main terminals 7 are arranged on two sides of the molded part 8 and the control terminals 6 are arranged on the other two sides when viewed from above. However, the arrangement of the main terminals 7 and the control terminals 6 is not limited to this. FIGS. 5 and 6 are top views of the power module 202 according to a modification of the first embodiment. As shown in FIG. 5, the main terminals 7 may be arranged on one side and the control terminals 6 on the other two sides, or as shown in FIG. 6, the main terminals 7 and the control terminals 6 may be arranged in a mixed manner on one side, and thus the design can be freely performed. In this way, by arranging the main terminals 7 and the control terminals 6 on multiple sides of the power module 202, there is an advantage that the degree of freedom in designing the electrical wiring (e.g., aluminum wire) inside the power module 202 is increased.

[0026] Fig. 7 is a cross-sectional view showing a screw-fastened connection between main terminal 7 and bus bar 10 included in power module 202 according to a modification of embodiment 1. Fig. 8 is a top view showing a screw-fastened connection between main terminal 7 and bus bar 10 included in power module 202 according to a modification of embodiment 1.

[0027] As shown in Fig. 7, the easiest and most productive method of connecting the main terminal 7 and the bus bar 10 is to fasten the main terminal 7 to the bus bar 10 using a screw 14 and a nut 15. The screw fastening will now be described. As shown in Fig. 8, a cut hole 7d is provided in the main terminal 7, and a cut hole 10a is provided in the bus bar 10 at a position corresponding to the cut hole 7d. The screw fastening is performed by fastening the nut 15 to the shaft of the screw 14 with the shank of the screw 14 inserted through the cut hole 10a and the cut hole 7d.

[0028] Note that the busbar 10 may be disposed above the main terminal 7, with the screws 14 disposed above the busbar 10 and the nuts 15 disposed below the main terminal 7, and the connection may be made by fastening with the screws, or the busbar 10 may be disposed below the main terminal 7, with the screws 14 disposed above the main terminal 7 and the nuts 15 disposed below the busbar 10, and the connection may be made by fastening with the screws. Note that, although this reduces productivity, it is also possible to switch the screws 14 and nuts 15 in each arrangement and fasten with the screws.

[0029] Fig. 9 is a cross-sectional view showing a screw-fastened connection between main terminal 7 and nut-equipped bus bar 16 provided in power module 202 according to a modified example of embodiment 1. Furthermore, in order to connect bus bars 10 with good productivity, it is also possible to use nut-equipped bus bar 16 having nuts 15 inserted into bus bar 10 as shown in Fig. 9, and connect main terminal 7 and nut-equipped bus bar 16 by screw-fastening.

[0030] Fig. 10 is a cross-sectional view showing a screw-fastened connection between nut-equipped main terminal 17 included in power module 202 according to a modification of embodiment 1 and bus bar 10. Fig. 11 is a cross-sectional view showing a screw-fastened connection between main terminal 7, on which screw fastening auxiliary member 18 included in power module 202 according to a modification of embodiment 1 is disposed, and bus bar 10.

[0031] Similarly, as shown in Fig. 10, it is also possible to use a nut-equipped main terminal 17 in which a nut 15 is inserted into a main terminal 7, and connect it to the bus bar 10 by screw fastening. In this case, a lead frame 3 in which a nut 15 is inserted into the main terminal 7 is used and molded. Alternatively, after molding, the nut 15 is inserted into the main terminal 7 after terminal formation processing. Either method makes it possible to connect the nut-equipped main terminal 17 to the bus bar 10 by screw fastening.

[0032] Furthermore, if the main terminal 7 is formed to extend horizontally, when screwing the main terminal 7 and the bus bar 10 together, by inserting a screw fastening auxiliary member 18 as shown in FIG. 11, the main terminal 7 and the bus bar 10 can be connected together by screwing with good productivity.

[0033] In addition, by arranging auxiliary screw fastening member 18 and connecting main terminal 7 and bus bar 10 by screw fastening, it is possible to control the displacement applied to main terminal 7 when screwed fastening, and it is possible to reduce the stress applied to the interface between molded portion 8 and main terminal 7 when screwed fastening, which has the advantage of reducing the defect rate.

[0034] Fig. 12 is a cross-sectional view showing the positional relationship between a main terminal 7 and a screw fastening auxiliary member 18 included in a power module 202 according to a modification of the first embodiment. Fig. 13 is a cross-sectional view showing the positional relationship between a main terminal 7 and a screw fastening auxiliary member 20 with elasticity function included in a power module 202 according to a modification of the first embodiment.

[0035] Here, due to the tolerance of each component and warping of the molded portion 8, the positional relationship in the height direction between the main terminal 7 and the screw fastening auxiliary member 18 on which the nut 15 is arranged does not necessarily have zero clearance, as shown in FIG. 12. In other words, as shown in FIG. 12, there is either a clearance (displacement) between the main terminal 7 and the screw fastening auxiliary member 18, or the main terminal 7 and the screw fastening auxiliary member 18 interfere with each other. If the displacement applied when connecting the busbar 10 to the main terminal 7, that is, the clearance between the main terminal 7 and the screw fastening auxiliary member 18, is large, there is a concern that a large stress will be applied to the interface between the molded portion 8 and the main terminal 7 during screw fastening, causing peeling and cracking at the interface. For this reason, it is desirable to reduce the clearance between the main terminal 7 and the screw fastening auxiliary member 18.

[0036] As shown in FIG. 13, by using a screw fastening auxiliary member 20 with elastic function, in which an elastic material 19 is disposed between a screw fastening auxiliary member 18 and a base portion 11, it is possible to make a connection with higher productivity and also to pass a large current through the power module 202.

[0037] Fig. 14 is a cross-sectional view showing connection by solder 2 between main terminal 7 and bus bar 10 provided in power module 202 according to a modification of embodiment 1. Fig. 15 is a cross-sectional view showing connection by welding between main terminal 7 and bus bar 10 provided in power module 202 according to a modification of embodiment 1. Fig. 16 is a cross-sectional view showing connection by crimping between main terminal 7 and bus bar 10 provided in power module 202 according to a modification of embodiment 1.

[0038] Here, the connection between the main terminal 7 and the bus bar 10 can be made not only by screw fastening, but also by any other connection method, such as connection using a bonding material such as solder 2 as shown in Fig. 14, connection by welding as shown in Fig. 15, or connection by crimping as shown in Fig. 16. Any of the connection methods can obtain sufficient connection strength, stably reduce the contact electrical resistance and contact thermal resistance, and increase the contact area between the bus bar 10 and the main terminal 7, thereby suppressing the temperature rise of the main terminal 7 during product use. Here, reference numeral 22a in Fig. 15 indicates a welded portion.

[0039] It is also possible to combine several connection methods, such as screw fastening and crimping. By combining connection methods, the connection strength can be further improved, the contact electrical resistance and contact thermal resistance can be further stably reduced, and the contact area between the busbar 10 and the main terminal 7 can be further increased compared to the case where only one type of connection is used, so that the temperature rise of the main terminal 7 during product use can be further suppressed.

[0040] <Other Modifications> 17 to 19 are cross-sectional views of a power module 202 according to a modified example of the first embodiment. FIG. 1 shows an example in which a crimped heat sink is used as the heat sink 13, in which a base portion 11 and a plurality of heat dissipation fins 12 are integrated by crimping. The base portion 11 is processed by machining, die-casting, forging, extrusion, or the like, and is made of aluminum or an aluminum alloy. The heat dissipation fins 12 are made of a plate material such as aluminum or an aluminum alloy, which makes it possible to achieve both workability and heat dissipation properties.

[0041] However, both the base portion 11 and the heat dissipation fins 12 are not limited to being made of aluminum material, and they may be a combination of different materials. For example, from the standpoint of heat dissipation capacity, by making the heat dissipation fins 12 out of a copper-based plate material, which has a higher thermal conductivity than aluminum-based materials, the heat dissipation capacity can be further improved compared to the case of aluminum-based materials.

[0042] Furthermore, the heat sink 13 is not limited to a crimped heat sink, but may be an extruded heat sink made by extrusion processing as shown in FIG. 17, a machined heat sink made by cutting processing, a forged heat sink made by forging, or a die-cast heat sink made by die-cast processing as shown in FIG. 18.

[0043] 19, the module base 5 and the heat sink 13 may be integrated with a bonding material such as solder 2 and an adhesive. It is also possible to integrate the module base 5 and the heat sink 13 with each other by combining a number of methods, such as using a crimping process and a bonding material.

[0044] The module base 5 is processed by machining, die casting, forging, extrusion, or the like, and is made of aluminum or an aluminum alloy. However, the material of the module base 5 is not limited to aluminum, and by using a copper-based plate material that has a higher thermal conductivity than aluminum-based materials, the heat dissipation capacity is further improved compared to aluminum-based materials.

[0045] The semiconductor chip 1 may be made of silicon or wide bandgap semiconductors such as silicon carbide and gallium nitride.

[0046] The material of the lead frame 3 and the bus bar 10 is preferably a copper-based material or an aluminum-based material from the viewpoint of electrical resistivity and workability, but is not limited to this so long as it is a metallic material.

[0047] <Effects> As described above, in the first embodiment, the power module 202 comprises a semiconductor chip 1, a lead frame 3 having the semiconductor chip 1 mounted on one side thereof, a module base 5 having the lead frame 3 arranged on one side thereof, a main terminal 7 which is a part of the lead frame 3, a molded portion 8 which seals the semiconductor chip 1, the lead frame 3, and the module base 5 so that the main terminal 7 is exposed, a heat sink 13 which is integrated with the other side of the module base 5 exposed from the molded portion 8, and a bus bar 10 which is connected to a first main surface of the main terminal 7 or a second main surface opposite to the first main surface, wherein the second main surface of the main terminal 7 faces the heat sink 13 and the first main surface of the main terminal 7 faces the opposite side to the heat sink 13.

[0048] The method for manufacturing the power module 202 also includes a step (a) of connecting the bus bar 10 to the first or second main surface of the main terminal 7 by screwing, bonding, or crimping.

[0049] Therefore, since terminal forming processing is not required on the first and second main surfaces of the main terminal 7, the areas of the first and second main surfaces can be increased. As a result, in the heat sink-integrated power module 202, the bus bar 10 can be connected to the main terminal 7, making it possible to suppress a temperature rise in the main terminal 7. As a result, it becomes possible to pass a large current through the power module 202.

[0050] Furthermore, since bus bar 10 is connected to the first or second main surface of main terminal 7 by screw 14 and nut 15, bus bar 10 can be connected to main terminal 7 in a simple manner with good productivity.

[0051] The heat sink 13 also has a base portion 11 integrated with the other side of the module base 5, and a plurality of heat dissipation fins 12 protruding from the base portion 11 on the side opposite the module base 5, and the main terminals 7 extend in a first direction which is parallel to the base portion 11 of the heat sink 13, and are exposed from the molded portion 8.

[0052] Therefore, terminal forming processing is not required on the first and second main surfaces of the main terminal 7, and the areas of the first and second main surfaces can be increased. Also, since terminal forming processing is performed only on the control terminal 6 having a small terminal cross-sectional area as necessary, there is no need to increase the size of the equipment, and the productivity of the power module is improved.

[0053] In addition, the main terminal 7 has a first parallel portion 7a exposed from the molded portion 8 in a first direction which is parallel to the base portion 11 of the heat sink 13, a first vertical portion 7b extending from the first parallel portion 7a in a second direction which is vertical, and a second parallel portion 7c extending from the first vertical portion 7b in the first direction, and the busbar 10 is connected to the second parallel portion 7c of the main terminal 7.

[0054] Therefore, it is possible to reduce the stress applied to the interface between the main terminal 7 and the molded portion 8 when the main terminal 7 and the bus bar 10 are connected. Similarly, it is also possible to reduce the stress applied to the interface between the main terminal 7 and the molded portion 8 when vibrations occur during use of the product, improving the vibration resistance of the product.

[0055] In addition, an engaging portion 5a is provided on the other side of the module base 5, and a mating portion 11a that can engage with the engaging portion 5a is provided on the surface of the base portion 11 of the heat sink 13 facing the module base 5, and the module base 5 and the heat sink 13 are integrated by the engaging portion 5a and the mating portion 11a engaging with each other.

[0056] Therefore, integration can be achieved in a room temperature process, and the equipment does not become large and complicated, thereby improving productivity.

[0057] <Embodiment 2> Next, a power module 202 according to the second embodiment will be described. Fig. 20 is a cross-sectional view of the power module 202 according to the second embodiment. Fig. 21 is a top view of the power module 202 according to the second embodiment. Note that in the second embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0058] 20 and 21, in the second embodiment, the power module 202 further includes a terminal block 25 (a structural member for displacement control) in comparison with the first embodiment. The terminal block 25 is fixed onto the outer periphery of the base portion 11 of the heat sink 13, and is disposed between the main terminal 7 and the base portion 11.

[0059] 20, bus bar 10 is arranged above main terminal 7, and terminal block 25 is arranged below main terminal 7, but this is not limited thereto, and bus bar 10 may be arranged below main terminal 7, and terminal block 25 may be arranged further below bus bar 10. Terminal block 25 is made of resin from the viewpoints of workability and insulation. However, it is not necessarily required to be made of resin, and it may be made of a metal material.

[0060] Next, the connection between the terminal block 25 and the base portion 11, and the connection between the main terminal 7 and the bus bar 10 will be described. FIG. 22 is a cross-sectional view showing the connection between the terminal block 25 and the heat sink 13 included in the power module 202 according to the second embodiment by screw fastening. FIG. 23 is a cross-sectional view showing the connection between the terminal block 25 and the heat sink 13 included in the power module 202 according to the modified example of the second embodiment by solder 2. FIG. 24 is a cross-sectional view showing the connection between the terminal block 25 and the heat sink 13 included in the power module 202 according to the modified example of the second embodiment by welding. FIG. 25 is a cross-sectional view showing the connection between the terminal block 25 and the heat sink 13 included in the power module 202 according to the modified example of the second embodiment by crimping. FIG. 26 is a cross-sectional view showing the connection between the main terminal 7 and the bus bar 10 included in the power module 202 according to the modified example of the second embodiment by screw fastening. FIG. 27 is a cross-sectional view showing the connection between the main terminal 7 and the bus bar 10 included in the power module 202 according to the modified example of the second embodiment by solder 2. Fig. 28 is a cross-sectional view showing connection by welding between main terminal 7 and bus bar 10 included in power module 202 according to a modification of embodiment 2. Fig. 29 is a cross-sectional view showing connection by crimping between main terminal 7 and bus bar 10 included in power module 202 according to a modification of embodiment 2.

[0061] The terminal block 25 and the base portion 11 of the heat sink 13 may be fixed to each other by any of the following connection methods: screw fastening as shown in Fig. 22, connection using a bonding material such as solder 2 as shown in Fig. 23, connection using welding as shown in Fig. 24, or connection using crimping as shown in Fig. 25. The main terminal 7 and the bus bar 10 may be connected to each other by any of the following connection methods: screw fastening as shown in Fig. 26, connection using a bonding material such as solder 2 as shown in Fig. 27, connection using welding as shown in Fig. 28, or connection using crimping as shown in Fig. 29. Reference numeral 22a in Figs. 24 and 28 denotes a welded portion, and reference numeral 22b in Fig. 25 denotes a crimped portion.

[0062] By further providing terminal block 25, power module 202 can control the displacement applied to main terminal 7 and reduce the stress applied to the interface between molded portion 8 and main terminal 7, thereby reducing the rate of defects in the process of connecting bus bar 10 to main terminal 7. In addition, the clearance between main terminal 7 or bus bar 10 and terminal block 25 can be controlled when the product is in use. This makes it possible to reduce displacement during vibration, thereby reducing the stress applied to the interface between molded portion 8 and main terminal 7, improving the vibration resistance of the product.

[0063] Regarding the screw fastening structure, as shown in FIG. 26, nuts 15 are placed on terminal block 25 fixed to base portion 11 of heat sink 13, and main terminal 7 and bus bar 10 are connected; alternatively, terminal block 25 with nuts 15 placed thereon is fixed to base portion 11, and main terminal 7 and bus bar 10 are connected; this can be achieved in a simple manner with good productivity.

[0064] 30(a) and (b) are cross-sectional views showing a connection by screw fastening between a main terminal 7 and a bus bar 10 using a main terminal with nuts 17 or a bus bar with nuts 16 included in a power module 202 according to a modification of the second embodiment. As shown in Fig. 30(a), a space 25a for nuts 15 is provided in a terminal block 25, a main terminal with nuts 17 is used, a bus bar 10 is placed above the main terminal with nuts 17, and the connection is made by screw fastening. Alternatively, as shown in Fig. 30(b), a space 25a for nuts 15 may be provided in a terminal block 25, a bus bar with nuts 16 is used, a main terminal 7 is placed above the bus bar with nuts 16, and the connection may be made by screw fastening.

[0065] The soldered joint structure can be realized with good productivity by a simple method using a structure as shown in Fig. 27. The welded structure can be realized with good productivity by a simple method using welding or brazing as shown in Fig. 28.

[0066] Regarding the crimp connection structure, as shown in Fig. 29(a) and (b), a space 10b for crimping is provided in the busbar 10, and the busbar 10 and the main terminal 7 are connected by applying pressure from the busbar 10 to the main terminal 7 formed to correspond to the shape of the space 10b. This simple method can be realized with good productivity. In Fig. 29(a), the space 10b is triangular in cross section, and in Fig. 29(b), the space 10b is trapezoidal in cross section. In Fig. 29, pressure is applied from the busbar 10 to the main terminal 7, but this is not limited thereto, and a space may be provided in the main terminal 7, and pressure may be applied from the main terminal 7 to the busbar 10 for crimping.

[0067] FIG. 31 is a cross-sectional view showing the arrangement of terminal block 25 having a positioning structure included in power module 202 according to a modification of the second embodiment.

[0068] As shown in FIG. 31, by providing a positioning groove 26a on the base portion 11 of the heat sink 13 and providing a convex positioning portion 26 that can fit into the groove 11b on the terminal block 25, the terminal block mounting process can be simplified and productivity improved.

[0069] 32(a) and (b) are cross-sectional views showing the arrangement of terminal block 25 having a positioning structure included in power module 202 according to a modification of embodiment 2, and FIG. 32(c) is a side view. Also, FIG. 32(d) and (e) are top views showing the arrangement of terminal block 25 having a positioning structure included in power module 202 according to a modification of embodiment 2.

[0070] The positioning portion 26 of the terminal block 25 is not limited to the structure shown in FIG. 31, and may have any structure as long as it can determine the position of the terminal block 25 in at least one direction, for example, as shown in FIGS. 32(a) to (e). Specifically, as shown in FIG. 32(a), a positioning groove 26a may be provided in the terminal block 25, and a T-shaped positioning portion 26 in a cross-sectional view may be provided in the base portion 11. Alternatively, as shown in FIG. 32(b), the entire lower end portion of the terminal block 25 may be the positioning portion 26, and a groove 26a into which the positioning portion 26 can be fitted may be provided in the base portion 11. Alternatively, as shown in FIG. 32(c), two convex positioning portions 26 may be provided in the base portion 11, and two grooves 26a may be provided in the terminal block 25. Alternatively, as shown in FIG. 32(d), the positioning portion 26 provided in the base portion 11 may have a shape of two crosses connected together in a top view. Alternatively, as shown in FIG. 32(e), the two positioning portions 26 provided on the base portion 11 may both be cylindrical.

[0071] Next, the clearance between the main terminal 7 and the terminal block 25 will be described. Fig. 33 is a cross-sectional view showing the clearance between the main terminal 7 and the terminal block 25 included in the power module 202 according to the modification of the second embodiment. Fig. 34 is a cross-sectional view showing the connection by screw fastening of the main terminal 7 and the bus bar 10 in a case where a clearance exists between the main terminal 7 and the terminal block 25 included in the power module 202 according to the modification of the second embodiment. Fig. 35 is a cross-sectional view showing the clearance between the main terminal 7 and the terminal block 25 in a case where the terminal block 27 with elasticity function included in the power module 202 according to the modification of the second embodiment is used.

[0072] Due to the tolerance of each component and the occurrence of warping in the molded portion 8, the positional relationship in the height direction between the main terminal 7 and the terminal block 25 does not necessarily have a zero clearance, as shown in Fig. 33. In other words, as shown in Fig. 33, there will be either a clearance (displacement) between the main terminal 7 and the terminal block 25, or the main terminal 7 and the terminal block 25 will interfere with each other. If the displacement applied when connecting the main terminal 7 and the busbar 10, that is, the clearance between the main terminal 7 and the terminal block 25, is large, as shown in Fig. 34, a large stress will be applied to the interface between the molded portion 8 and the main terminal 7 when the screws are fastened, which may cause peeling and cracking at the interface, and therefore it is desirable to reduce the clearance between the main terminal 7 and the terminal block 25.

[0073] Therefore, by using a terminal block 27 with elastic function, in which an elastic material 19 is arranged between the terminal block 25 and the base portion 11 as shown in FIG. 35, it is possible to pass a large current through the power module 202 with even better productivity.

[0074] In the second embodiment, terminal block 25 with nuts 15 is used to connect main terminal 7 and bus bar 10 by screw fastening, but this is not limited thereto, and the same effect can be obtained by using terminal block 27 with elasticity function even when main terminal 7 and bus bar 10 are connected by soldering, welding, or crimping. Also, the main terminal 7 has been described as extending horizontally, but it may have a shape as shown in Fig. 4, in which case terminal block 25 is disposed between second parallel portion 7c and base portion 11, or between bus bar 10 disposed below second parallel portion 7c and base portion 11.

[0075] As described above, in the second embodiment, power module 202 is fixed onto base portion 11 of heat sink 13, and further includes terminal block 25 disposed between main terminal 7 or bus bar 10 and base portion 11.

[0076] In addition, the manufacturing method of the power module 202 includes a step (a) of connecting the bus bar 10 to the first or second main surface of the main terminal 7 by screwing, joining, or crimping, and a step (b) of fixing the terminal block 25 to the base portion 11 of the heat sink 13 while the terminal block 25 is in contact with the main terminal 7 or the bus bar 10.

[0077] Therefore, the displacement applied to the main terminal 7 can be controlled with good productivity, and it is possible to reduce the stress applied to the interface between the main terminal 7 and the molded portion 8 when the main terminal 7 is connected to the bus bar 10. Similarly, when the product is in use, the clearance between the main terminal 7 or the bus bar 10 and the terminal block 25 can be controlled, and it is possible to reduce the stress applied to the interface between the main terminal 7 and the molded portion 8 during vibration, improving the vibration resistance of the product.

[0078] Furthermore, since terminal block 25 is in contact with main terminal 7 or bus bar 10, the power module and terminal block 25 vibrate together during vibration, further improving the vibration resistance of the product.

[0079] In addition, the power module 202 further includes an elastic material 19 arranged between the terminal block 25 and the base portion 11. Therefore, even if there is a vertical clearance between the main terminal 7 or the bus bar 10 and the terminal block 25, the elastic material 19 enables the main terminal 7 or the bus bar 10 to come into contact with the terminal block 25.

[0080] <Embodiment 3> Next, a power module 202 according to embodiment 3 will be described. A cross-sectional view and a top view of the power module 202 according to embodiment 3 are similar to those of embodiment 2, and will be described using Fig. 20 and Fig. 21. Note that in embodiment 3, the same components as those described in embodiments 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.

[0081] 20 and 21, in addition to the bus bar 10, a terminal block 25 fixed to the heat sink 13 is connected to the main terminal 7. Here, in FIG. 20, the bus bar 10 is arranged above the main terminal 7, and the terminal block 25 is connected below the main terminal 7, but this is not limited thereto, and the bus bar 10 may be arranged below the main terminal 7, and the terminal block 25 may be arranged further below the bus bar 10.

[0082] The terminal block 25 and the base portion 11 of the heat sink 13 may be fixed by any connection method, such as connection by screw fastening as shown in FIG. 22, connection by a bonding material such as solder 2 as shown in FIG. 23, connection by welding as shown in FIG. 24, or connection by crimping as shown in FIG. 25.

[0083] Fig. 36 is a cross-sectional view showing the connection by screw fastening of the main terminal 7, the bus bar 10, and the terminal block 25 provided in the power module 202 according to the third embodiment. Fig. 37 is a cross-sectional view showing the connection by solder 2 of the main terminal 7, the bus bar 10, and the terminal block 25 provided in the power module 202 according to the third embodiment. Fig. 38 is a cross-sectional view showing the connection by welding of the main terminal 7, the bus bar 10, and the terminal block 25 provided in the power module 202 according to the third embodiment. Figs. 39(a) and (b) are cross-sectional views showing the connection by crimping of the main terminal 7, the bus bar 10, and the terminal block 25 provided in the power module 202 according to the third embodiment.

[0084] Furthermore, the main terminals 7, the busbars 10, and the terminal block 25 may be connected by any method, such as screw fastening as shown in Fig. 36, connection using a joining material such as solder 2 as shown in Fig. 37, connection by welding as shown in Fig. 38, or connection by crimping as shown in Fig. 39(a) and (b). This makes it possible to control the displacement applied to the main terminals 7 with good productivity and reduce the stress applied to the interface between the molded portion 8 and the main terminals 7, thereby reducing the rate of defects in the process of connecting the main terminals 7 and the busbars 10.

[0085] Regarding the screw fastening structure, the nut 15 may be fixed to the terminal block 25 by any method, such as inserting the nut 15 when molding the terminal block 25, pressing the nut 15 after molding the terminal block 25, or joining the nut 15 using a joining material.

[0086] Fig. 40 is a cross-sectional view showing a terminal block 25 having a metal member 28 for preventing the nut from falling off, which is provided in a power module 202 according to embodiment 3. As shown in Fig. 40, in order to realize a power module 202 with even better productivity, a space 25a for arranging the nut 15 may be provided in the terminal block 25, the nut 15 may be arranged in the space 25a, a metal member 28 having a U-shape in cross section for preventing the nut from falling off may be arranged on the nut 15, and the metal member 28 may be inserted into the terminal block 25 in a state in which the upward movement of the nut 15 is restricted by the metal member 28.

[0087] As for the crimp connection structure, as shown in Fig. 39(a), a crimping space 25b is provided in terminal block 25, and pressure is applied from bus bar 10 to main terminal 7 and terminal block 25 to connect main terminal 7 and bus bar 10 to terminal block 25, or as shown in Fig. 39(b), a crimping space 10b is provided in bus bar 10, and pressure is applied from bus bar 10 to main terminal 7 and terminal block 25, which are formed to correspond to the shape of space 10b, to connect main terminal 7 and bus bar 10 to terminal block 25, thereby making it possible to realize the crimp connection structure in a simple manner with good productivity. Since main terminal 7 and bus bar 10 are connected to terminal block 25 fixed to heat sink 13 integrated with power module part 9, stress applied to main terminal 7 due to vibrations generated during use of the product can be reduced, improving the vibration resistance of the product.

[0088] Here, the reason why the vibration resistance is improved when the product is in use will be described. Fig. 41 is a cross-sectional view showing a state of power module 202 according to embodiment 3 when the product is in use. Fig. 42 is a cross-sectional view showing a general power module 302 when the product is in use.

[0089] As shown in FIG. 41, when the product is used, the heat sink 13 is fixed to the unit frame 29 of the product by screw fastening or the like. In a typical power module 302 as shown in FIG. 42, a terminal block 30 is arranged inside the power module 302, and the power module part 9 and the heat sink 13 are fixed by screws 14 with a heat dissipation member 34 such as thermal conductive grease between the power module part 9 and the heat sink 13, i.e., between the metal member 32 arranged under the insulating member 4 and the base part 11. Therefore, when the product vibrates, the unit frame 29 and the heat sink 13 vibrate in a fixed state, but the components (main terminal 7 and bus bar 10) located on the upper part of the power module part 9 connected to the heat sink 13 via the heat dissipation member 34 vibrate separately. As a result, excessive stress due to vibration is applied between the main terminal 7 and the bus bar 10, which may cause problems such as terminal breakage.

[0090] 41, power module 202 according to embodiment 3 includes terminal block 25 and main terminal 7 fixed to heat sink 13, and bus bar 10 connected to main terminal 7, so that power module 202 fixed to unit frame 29 and each connection part vibrate together. This makes it possible to reduce the stress applied to the interface between molded part 8 and main terminal 7 when the product vibrates, improving the vibration resistance of the product.

[0091] Fig. 43 is a cross-sectional view showing a clearance between the main terminal 7 and terminal block 25 included in the power module 202 according to the embodiment 3. Fig. 44 is a cross-sectional view showing a connection by screw fastening of the main terminal 7, the bus bar 10, and the terminal block 25 in a case where a clearance exists between the main terminal 7 and terminal block 25 included in the power module 202 according to the embodiment 3. Fig. 45 is a cross-sectional view showing the clearance between the main terminal 7 and terminal block 25 in a case where the terminal block 27 with elastic function included in the power module 202 according to the embodiment 3 is used.

[0092] Here, when connecting the main terminal 7, bus bar 10, and terminal block 25, tolerances of each component and warping of the molded portion 8 occur, so that the vertical positional relationship between the main terminal 7 and the terminal block on which the nut 15 is arranged does not necessarily result in zero clearance, as shown in Figure 43.

[0093] That is, as shown in Fig. 43, either a clearance (displacement) exists between the main terminal 7 and the terminal block 25 on which the nut 15 is arranged, or the terminal block 25 on which the nut 15 is arranged interferes with the main terminal 7. If the displacement that occurs when connecting the main terminal 7 to the busbar 10, that is, the clearance between the main terminal 7 and the terminal block 25 on which the nut 15 is arranged, is large, as shown in Fig. 44, a large stress is applied to the interface between the molded part 8 and the main terminal 7 when the screws are fastened, which may cause peeling and cracks at the interface, and therefore it is desirable to reduce the clearance between the main terminal 7 and the terminal block 25 on which the nut 15 is arranged.

[0094] Therefore, by using a terminal block 27 with elastic function, in which an elastic material 19 is arranged between the terminal block 25 on which the nut 15 is placed and the base portion 11 as shown in FIG. 45, it is possible to improve productivity and allow a large current to flow through the power module 202.

[0095] In the third embodiment, the main terminal 7 and the bus bar 10 are connected by screw fastening using the terminal block 25 with the nut 15, but this is not limited thereto, and the same effect can be obtained when the main terminal 7 and the bus bar 10 are connected by soldering, welding, or crimping by using the terminal block 27 with elasticity function. Also, the main terminal 7 has been described as extending horizontally, but it may have a shape as shown in Fig. 4, in which case the terminal block 25 is disposed between the second parallel portion 7c and the base portion 11, or between the bus bar 10 disposed below the second parallel portion 7c and the base portion 11.

[0096] As described above, in embodiment 3, in addition to bus bar 10, terminal block 25 fixed to heat sink 13 is connected to main terminal 7, so that the stress applied to main terminal 7 due to vibrations generated during use of the product can be reduced, improving the vibration resistance of the product.

[0097] <Fourth embodiment> In this embodiment, the power module 202 according to the above-mentioned embodiments 1 to 3 is applied to a power conversion device. Although the application of the power module 202 according to the embodiments 1 to 3 is not limited to a specific power conversion device, a case where the power module 202 according to the embodiments 1 to 3 is applied to a three-phase inverter will be described below as embodiment 4.

[0098] FIG. 46 is a block diagram showing a configuration of a power conversion system to which the power conversion device according to this embodiment is applied.

[0099] The power conversion system shown in Fig. 46 is composed of a power source 100, a power conversion device 200, and a load 300. The power source 100 is a DC power source and supplies DC power to the power conversion device 200. The power source 100 can be composed of various things, for example, a DC system, a solar cell, or a storage battery, or it may be composed of a rectifier circuit connected to an AC system or an AC / DC converter. The power source 100 may also be composed of a DC / DC converter that converts DC power output from a DC system into a predetermined power.

[0100] The power conversion device 200 is a three-phase inverter connected between the power source 100 and the load 300, converts DC power supplied from the power source 100 into AC power, and supplies the AC power to the load 300. As shown in Fig. 46, the power conversion device 200 includes a main conversion circuit 201 that converts DC power into AC power and outputs it, and a control circuit 203 that outputs a control signal for controlling the main conversion circuit 201 to the main conversion circuit 201.

[0101] The load 300 is a three-phase motor driven by AC power supplied from the power conversion device 200. The load 300 is not limited to a specific use, but is a motor mounted on various electric devices, and is used as, for example, a motor for a hybrid car, an electric car, a railroad car, an elevator, or an air conditioner.

[0102] The power conversion device 200 will be described in detail below. The main conversion circuit 201 includes switching elements (not shown) and free wheel diodes (not shown), and converts DC power supplied from the power source 100 into AC power by switching the switching elements, and supplies the AC power to the load 300. There are various specific circuit configurations of the main conversion circuit 201, but the main conversion circuit 201 according to this embodiment is a two-level three-phase full bridge circuit, and can be configured with six switching elements and six free wheel diodes connected in reverse parallel to each switching element. The power module 202 according to any one of the above-mentioned embodiments 1 to 3 is applied to at least one of the switching elements and free wheel diodes of the main conversion circuit 201. Two switching elements of the six switching elements are connected in series to configure upper and lower arms, and each upper and lower arm configures each phase (U phase, V phase, W phase) of the full bridge circuit. The output terminals of each upper and lower arm, i.e., the three output terminals of the main conversion circuit 201, are connected to the load 300.

[0103] The main conversion circuit 201 also includes a drive circuit (not shown) for driving each switching element, but the drive circuit may be built in the power module 202, or the drive circuit may be provided separately from the power module 202. The drive circuit generates drive signals for driving the switching elements of the main conversion circuit 201 and supplies them to the control electrodes of the switching elements of the main conversion circuit 201. Specifically, in accordance with a control signal from a control circuit 203 (described later), the drive circuit outputs to the control electrodes of each switching element a drive signal for turning the switching element on and a drive signal for turning the switching element off. When maintaining a switching element in the on state, the drive signal is a voltage signal (on signal) equal to or higher than the threshold voltage of the switching element, and when maintaining a switching element in the off state, the drive signal is a voltage signal (off signal) equal to or lower than the threshold voltage of the switching element.

[0104] The control circuit 203 controls the switching elements of the main conversion circuit 201 so that a desired power is supplied to the load 300. Specifically, the control circuit 203 calculates the time (on time) for each switching element of the main conversion circuit 201 to be in the on state based on 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 switching elements according to the voltage to be output. Then, a control command (control signal) is output to a drive circuit provided in the main conversion circuit 201 so that an on signal is output to a switching element that should be in the on state at each time point, and an off signal is output to a switching element that should be in the off state. The drive circuit outputs an on signal or an off signal as a drive signal to the control electrode of each switching element according to this control signal.

[0105] In the power conversion device according to the present embodiment, the power modules 202 according to the first to third embodiments are applied as the switching elements and free wheel diodes of the main conversion circuit 201, and therefore it is possible to realize improvement in productivity.

[0106] In the present embodiment, an example in which the power module 202 according to the first to third embodiments is applied to a two-level three-phase inverter has been described, but the application of the power module 202 according to the first to third embodiments is not limited to this, and the power module 202 can be applied to various power conversion devices. In the present embodiment, the power module 202 is a two-level power conversion device, but it may be a three-level or multilevel power conversion device, and when power is supplied to a single-phase load, the power module 202 according to the first to third embodiments may be applied to a single-phase inverter. Also, when power is supplied to a DC load or the like, the power module 202 according to the first to third embodiments can be applied to a DC / DC converter or an AC / DC converter.

[0107] Furthermore, the power conversion device to which the power module 202 according to the first to third embodiments is applied is not limited to the case where the load described above is an electric motor, but can also be used, for example, as a power supply device for an electric discharge machine, a laser processing machine, an induction heating cooker, or a non-contact power supply system, and can also be used as a power conditioner for a solar power generation system, a power storage system, or the like.

[0108] Although this disclosure has been described in detail, the above description is illustrative in all respects and is not restrictive. It is understood that countless variations not illustrated can be envisioned.

[0109] It should be noted that the embodiments can be freely combined, and each embodiment can be modified or omitted as appropriate.

[0110] Various aspects of the present disclosure are summarized below as appendices.

[0111] (Appendix 1) A semiconductor element; a frame having the semiconductor element mounted on one surface thereof; a module base having the frame disposed on one surface thereof; A main terminal that is a part of the frame; a mold part that seals the semiconductor element, the frame, and the module base so that the main terminals are exposed; and a heat sink including a base portion integrated with the other surface of the module base exposed from the mold portion, and a plurality of heat dissipation fins protruding from the base portion on a side opposite to the module base; an external terminal connected to a first main surface of the main terminal or a second main surface opposite to the first main surface; before Base part The outer periphery of the surface on the module base side and the main terminal or the external terminal and the base portion are fixed on the On the outer periphery of the surface on the module base side and a displacement control structure disposed between the The second main surface of the main terminal faces the heat sink, The first main surface of the main terminal faces away from the heat sink. (Appendix 2) 2. The power module according to claim 1, wherein a terminal cross-sectional area of ​​the main terminal is smaller than a terminal cross-sectional area of ​​the external terminal. (Appendix 3) 2. The power module according to claim 1, wherein the displacement control structure is fastened by screws onto an outer periphery of a surface of the base portion on the module base side. (Appendix 4) 2. The power module according to claim 1, wherein the displacement control structure is disposed only on an outer periphery of a surface of the base portion facing the module base.

[0112] (Addendum 5 ) 2. The power module according to claim 1, wherein the external terminal is connected to the first main surface or the second main surface of the main terminal by a screw and a nut.

[0113] (Addendum 6 ) 2. The power module according to claim 1, wherein the main terminal extends in a first direction parallel to the base portion of the heat sink and is exposed from the molded portion.

[0114] (Addendum 7 ) the main terminal has a first parallel portion exposed from the molded portion in a first direction parallel to the base portion of the heat sink, a first vertical portion extending from the first parallel portion in a second direction vertical to the base portion of the heat sink, and a second parallel portion extending from the first vertical portion in the first direction; 2. The power module according to claim 1, wherein the external terminal is connected to the second parallel portion of the main terminal.

[0115] (Addendum 8 ) 2. The power module of claim 1, wherein the displacement control structural member is in contact with the main terminal or the external terminal.

[0116] (Addendum 9 ) The displacement control structure further includes an elastic member disposed between the displacement control structure and the base portion. 8 The power module according to claim 1 .

[0117] (Addendum 10 ) a fitting portion is provided on the other surface of the module base, a mating portion that can be mated with the mating portion is provided on a surface of the base portion of the heat sink that faces the module base, The module base and the heat sink are integrated by fitting the fitting portion and the fitted portion together. 6 The power module according to claim 1 .

[0118] (Addendum 11 ) a fitting portion is provided on the other surface of the module base, a mating portion that can be mated with the mating portion is provided on a surface of the base portion of the heat sink that faces the module base, The module base and the heat sink are integrated by fitting the fitting portion and the fitted portion together. 7 The power module according to claim 1 .

[0119] (Addendum12 ) A method for manufacturing the power module according to claim 1, comprising the steps of: (a) connecting the external terminal to the first main surface or the second main surface of the main terminal by screwing, bonding, or crimping; (b) fixing the displacement control structure to the base portion of the heat sink in a state in which the displacement control structure is in contact with the main terminal or the external terminal; A method for manufacturing a power module comprising the steps of:

[0120] (Addendum 13 ) A main conversion circuit having the power module according to claim 1, which converts input power and outputs the converted power; a control circuit that outputs a control signal for controlling the main conversion circuit to the main conversion circuit; A power conversion device comprising: [Explanation of symbols]

[0121] 1 semiconductor chip, 3 lead frame, 5 module base, 5a mating portion, 7 main terminal, 7a first parallel portion, 7b first vertical portion, 7c second parallel portion, 8 molded portion, 10 bus bar, 11 base portion, 11a mating portion, 12 heat dissipation fin, 13 heat sink, 14 screw, 15 nut, 16 bus bar with nut, 17 main terminal with nut, 19 elastic material, 25 terminal block, 27 terminal block with elastic function, 200 power conversion device, 201 main conversion circuit, 202 power module, 203 control circuit.

Claims

1. A semiconductor element; a frame having the semiconductor element mounted on one surface thereof; a module base having the frame disposed on one surface thereof; A main terminal that is a part of the frame; a mold part that seals the semiconductor element, the frame, and the module base so that the main terminals are exposed; and a heat sink including a base portion integrated with the other surface of the module base exposed from the mold portion, and a plurality of heat dissipation fins protruding from the base portion on a side opposite to the module base; an external terminal connected to a first main surface of the main terminal or a second main surface opposite to the first main surface; a displacement control structural member fixed to an outer periphery of a surface of the base portion facing the module base and disposed between the main terminal or the external terminal and the outer periphery of the surface of the base portion facing the module base, The second main surface of the main terminal faces the heat sink, The first main surface of the main terminal faces away from the heat sink.

2. A power module as described in claim 1, wherein the terminal cross-sectional area of ​​the main terminal is smaller than the terminal cross-sectional area of ​​the external terminal.

3. A power module as described in claim 1, wherein the displacement control structural member is screwed onto the outer periphery of the surface of the base portion facing the module base.

4. A power module as described in claim 1, wherein the displacement control structural member is arranged only on the outer periphery of the surface of the base portion facing the module base.

5. The power module according to claim 1 , wherein the external terminal is connected to the first main surface or the second main surface of the main terminal by a screw and a nut.

6. The power module according to claim 1 , wherein the main terminal extends in a first direction that is parallel to the base portion of the heat sink, and is exposed from the molded portion.

7. the main terminal has a first parallel portion exposed from the molded portion in a first direction parallel to the base portion of the heat sink, a first vertical portion extending from the first parallel portion in a second direction vertical to the base portion of the heat sink, and a second parallel portion extending from the first vertical portion in the first direction; The power module according to claim 1 , wherein the external terminal is connected to the second parallel portion of the main terminal.

8. The power module according to claim 1 , wherein the displacement control structural member is in contact with the main terminal or the external terminal.

9. The power module according to claim 8 , further comprising an elastic member disposed between the displacement control structure and the base portion.

10. a fitting portion is provided on the other surface of the module base, a mating portion that can be mated with the mating portion is provided on a surface of the base portion of the heat sink that faces the module base, The power module according to claim 6 , wherein the module base and the heat sink are integrated by fitting the fitting portion and the fitted portion together.

11. a fitting portion is provided on the other surface of the module base, a mating portion that can be mated with the mating portion is provided on a surface of the base portion of the heat sink that faces the module base, The power module according to claim 7 , wherein the module base and the heat sink are integrated by fitting the fitting portion and the fitted portion together.

12. A method for manufacturing the power module according to claim 1, comprising the steps of: (a) connecting the external terminal to the first main surface or the second main surface of the main terminal by screwing, joining, or crimping; (b) fixing the displacement control structure to the base portion of the heat sink in a state in which the displacement control structure is in contact with the main terminal or the external terminal; A method for manufacturing a power module comprising the steps of:

13. A main conversion circuit having the power module according to claim 1, which converts input power and outputs the converted power; a control circuit that outputs a control signal for controlling the main conversion circuit to the main conversion circuit; A power conversion device comprising:

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