Power semiconductor device and power conversion device

Abstract

The purpose of the present invention is to provide technology capable of enhancing the heat dissipation of a heat sink. This power semiconductor device comprises: one or more heat sinks including heat-dissipating fins; and a plurality of semiconductor modules arranged along an airflow direction. First protrusion-and-recess parts are provided on a fin base of the semiconductor module, second protrusion-and-recess parts meshed with the first protrusion-and-recess parts are provided on the heat sink, and, in a plan view, the heat-dissipating fins continuously extend across two or more semiconductor modules adjacent to each other in the airflow direction among the plurality of semiconductor modules.

Description

Power semiconductor device and power conversion device

[0001] The present disclosure relates to a power semiconductor device and a power conversion device.

[0002] Various techniques have been proposed for power semiconductor devices. For example, Patent Document 1 proposes a technique for cooling a semiconductor element by mounting the semiconductor element on a heat sink.

[0003] Patent No. 6448732

[0004] In the technology of Patent Document 1, one semiconductor element is mounted on one heat sink. In such a configuration, when multiple sets of semiconductor elements and heat sinks are arranged side by side, there is a problem that spaces are created between the heat dissipation fins of adjacent heat sinks, which deteriorates heat dissipation performance.

[0005] Therefore, the present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a technique that can improve the heat dissipation performance of a heat sink.

[0006] a mounting plate having an opening through which the heat dissipation fins are inserted and on which the remaining portion of the heat sink other than the heat dissipation fins is mounted; and a cover member on which the mounting plate is mounted and which partially covers the heat dissipation fins; a fin base of the semiconductor module is provided on a portion facing the heat sink, and a second uneven portion engaged with the first uneven portion is provided on a portion of the heat sink facing the fin base; in a plan view, the heat dissipation fins extend continuously across two or more of the semiconductor modules that are adjacent in the airflow direction; the plurality of semiconductor modules arranged along the airflow direction include three or more of the semiconductor modules; and the two or more semiconductor modules across which the heat dissipation fins extend include the semiconductor module furthest downwind of the cooling fan.

[0007] According to the present disclosure, the first concave-convex portion of the fin base of the semiconductor module is fitted to the second concave-convex portion of the heat sink, and in a plan view, the heat dissipation fins extend continuously across two or more semiconductor modules that are adjacent in the airflow direction among the multiple semiconductor modules. This configuration can improve the heat dissipation performance of the heat sink. Objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings.

[0008] FIG. 1 is a cross-sectional view showing the configuration of an integrated power module according to a first embodiment. FIG. 2 is a plan view showing the configuration of a related device. FIG. 3 is a cross-sectional view taken along line A-A' showing the configuration of the related device. FIG. 4 is a plan view taken along line B-B' showing the configuration of the related device. FIG. 5 is a temperature contour diagram of the related device. FIG. 6 is a plan view showing the configuration of a power semiconductor device according to a first embodiment. FIG. 7 is a cross-sectional view taken along line C-C' showing the configuration of the power semiconductor device according to the first embodiment. FIG. 8 is a plan view showing the configuration of a power semiconductor device according to the first embodiment. FIG. 9 is a plan view showing the configuration of a power semiconductor device according to the first embodiment. FIG. 10 is a cross-sectional view showing a manufacturing method of a power semiconductor device according to the first embodiment. FIG. 11 is a plan view showing the configuration of a power semiconductor device according to a second embodiment. FIG. 12 is a cross-sectional view taken along line D-D' showing the configuration of a power semiconductor device according to the second embodiment. FIG. 13 is a plan view showing the configuration of a power semiconductor device according to the second embodiment. FIG. 14 is a plan view showing the configuration of a power semiconductor device according to the second embodiment. FIG. 15 is a cross-sectional view taken along line E-E' showing the configuration of a power semiconductor device according to the second embodiment. FIG. 16 is a cross-sectional view taken along line F-F' showing the configuration of a power semiconductor device according to a second embodiment. FIG. 17 is a cross-sectional view taken along line G-G' showing the configuration of a power semiconductor device according to a second embodiment. FIG. 18 is a plan view showing the configuration of a power semiconductor device according to a second embodiment. FIG. 19 is a plan view showing the configuration of a power semiconductor device according to a third embodiment. FIG. 20 is a cross-sectional view taken along line H-H' showing the configuration of a power semiconductor device according to a third embodiment. FIG. 21 is a cross-sectional view taken along line I-I' showing the configuration of a power semiconductor device according to a third embodiment. FIG. 22 is a plan view showing the configuration of a power semiconductor device according to a third embodiment. FIG. 23 is a plan view showing the configuration of a power semiconductor device according to a third embodiment. FIG. 24 is a plan view showing the configuration of a power semiconductor device according to a third embodiment. FIG. 25 is a cross-sectional view taken along line J-J' showing the configuration of a power semiconductor device according to a third embodiment. FIG. 26 is a plan view showing the configuration of a power semiconductor device according to a third embodiment. FIG. 27 is a plan view showing the configuration of a power semiconductor device according to a third embodiment. FIG. 28 is a cross-sectional view taken along line K-K' showing the configuration of a power semiconductor device according to a third embodiment.FIG. 29 is a cross-sectional view taken along line L-L' showing the configuration of a power semiconductor device according to a third embodiment. FIG. 30 is a plan view showing the configuration of a power semiconductor device according to the third embodiment. FIG. 31 is a plan view showing the configuration of a power semiconductor device according to a fourth embodiment. FIG. 32 is a cross-sectional view taken along line M-M' showing the configuration of a power semiconductor device according to the fourth embodiment. FIG. 33 is a cross-sectional view taken along line M-M' showing the configuration of a power semiconductor device according to the fourth embodiment. FIG. 34 is a block diagram showing the configuration of a power conversion system according to a fifth embodiment.

[0009] Hereinafter, embodiments will be described with reference to the accompanying drawings. Features described in each of the following embodiments are exemplary, and not all features are necessarily required. In addition, in the following description, similar components in multiple embodiments are denoted by the same or similar reference numerals, and different components will be mainly described. In addition, in the following description, specific positions and directions such as "upper," "lower," "left," "right," "front," or "back" may not necessarily correspond to positions and directions in actual implementation.

[0010] First Preferred Embodiment FIG. 1 is a cross-sectional view showing the configuration of an integrated power module 13 included in a power semiconductor device according to a first preferred embodiment.

[0011] The integrated power module 13 includes a semiconductor module 18 and a heat sink 12. The semiconductor module 18 includes a semiconductor element 1, a bonding member 2, metal wiring 3, a metal conductor 4, an insulating member 5, a control terminal 6, a main terminal 7, a sealing member 8, and a fin base 9.

[0012] The semiconductor element 1 includes, for example, any of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), an RC-IGBT (Reverse Conducting-IGBT), an SBD (Schottky Barrier Diode), and a PND (PN junction diode). The material of the semiconductor element 1 may be ordinary silicon (Si), silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga ２ O ３ ), or a wide band gap semiconductor such as diamond. When the material of the semiconductor element 1 is a wide band gap semiconductor, stable operation under high temperature and high voltage conditions and high switching speed can be achieved.

[0013] The bonding member 2 bonds the semiconductor element 1 to the metal conductor 4. The bonding member 2 is, for example, solder, and the metal conductor 4 is, for example, a lead frame. The metal wiring 3 selectively electrically connects the semiconductor element 1, the control terminal 6, and the main terminal 7, and the metal conductor 4, the control terminal 6, and the main terminal 7 are provided on the insulating member 5. The metal wiring 3 is, for example, a metal wire, and the insulating member 5 is, for example, an insulating sheet.

[0014] The sealing member 8 covers the semiconductor element 1, the bonding member 2, the metal wiring 3, the metal conductor 4, and the insulating member 5, and partially covers the control terminal 6 and the main terminal 7. The sealing member 8 also partially covers the fin base 9 and integrates the insulating member 5 with the fin base 9. The material of the sealing member 8 is an insulating resin such as an epoxy resin.

[0015] The fin base 9 transfers heat from the semiconductor element 1 to the heat sink 12. A first uneven portion 9a is provided on the portion of the fin base 9 that faces the heat sink 12. The fin base 9 is produced by, for example, cutting, forging, casting, or extrusion. The material of the fin base 9 may be, for example, aluminum or an aluminum alloy, or may be, for example, copper, or may be another metal.

[0016] The heat sink 12 includes a heat sink base 10 and heat dissipation fins 11. A second uneven portion 12a is provided on the heat sink base 10 of the heat sink 12 in a portion facing the fin base 9. The second uneven portion 12a of the heat sink 12 is fitted and fixed to the first uneven portion 9a of the fin base 9 by press working. With the integrated power module 13 in which the semiconductor module 18 and the heat sink 12 are integrated in this manner, the thermal resistance between the semiconductor module 18 and the heat sink 12 can be reduced without using thermal conductive grease. Furthermore, since pump-out and bleeding, which occur when using thermal conductive grease, do not occur, the reliability of the integrated power module 13 can be improved.

[0017] The heat sink base 10 is manufactured by, for example, cutting, die-casting, forging, extrusion, etc. The material of the heat sink base 10 is, for example, aluminum or an aluminum alloy. The heat dissipation fins 11 are, for example, plate members (rolled members) made of aluminum or an aluminum alloy, which are capable of both workability and heat dissipation.

[0018] The heat sink base 10 and the heat dissipation fins 11 are not limited to the above materials, and may be made of different materials. For example, from the viewpoint of heat dissipation capacity, if the heat dissipation fins 11 are made of a copper-based plate member, which has a higher thermal conductivity than aluminum-based materials, the heat dissipation capacity of the heat sink 12 can be improved.

[0019] The heat sink 12 in the example of FIG. 1 is a "crimped heat sink" in which the heat sink base 10 and the heat dissipation fins 11 are integrated by "crimping." When the heat sink 12 is a crimped heat sink as in the example of FIG. 1, processing constraints that arise in general heat sinks, such as aspect ratio constraints that arise in casting (die casting) and extrusion, can be suppressed. This increases the design freedom of the heat dissipation fins 11 and improves the heat dissipation capacity of the heat sink 12. However, the heat sink 12 according to the first embodiment is not limited to a crimped heat sink and may be a general heat sink that is manufactured as a whole in one piece by cutting, forging, extrusion, casting, or the like.

[0020] FIG. 2 is a plan view showing the configuration of a device related to the power semiconductor device of the first embodiment (hereinafter referred to as "related device"), FIG. 3 is a cross-sectional view taken along line A-A' in FIG. 2, and FIG. 4 is a plan view taken along line B-B' in FIG. 3.

[0021] The associated device includes a cooling fan 15, a cover member 16, a mounting plate 17, and six integrated power modules 13 (ie, integrated power modules 13A to 13F in FIG. 2).

[0022] The cooling fan 15 is a fan that draws in and draws out air (wind) as indicated by arrows 14. As shown in Fig. 4, the cooling fan 15 is provided so that the heat dissipation fins 11 extend along the airflow direction of the cooling fan 15. In other words, the heat dissipation fins 11 extend in the same direction as the airflow direction of the cooling fan 15, or in substantially the same direction.

[0023] 2, the integrated power modules 13A, 13C, and 13E on the left side are arranged in a row along the airflow direction of the cooling fan 15, and the integrated power modules 13B, 13D, and 13F on the right side are arranged in a row along the airflow direction of the cooling fan 15. In other words, the three integrated power modules 13 are arranged in the same direction as the airflow direction of the cooling fan 15 or in substantially the same direction.

[0024] As shown in Fig. 4, the mounting plate 17 has six openings 17a into which the heat dissipation fins 11 of the six integrated power modules 13 are respectively inserted. To enable such insertion, the area of ​​each opening 17a is larger than the total cross-sectional area of ​​all the heat dissipation fins 11 of one integrated power module 13. Also, as shown in Fig. 3, the heat sink base 10, which is the remaining portion of the heat sink 12 other than the heat dissipation fins 11, is mounted and fixed to the mounting plate 17.

[0025] A mounting plate 17 is mounted on the cover member 16, and the cover member 16 partially covers the heat dissipation fins. Although not shown, an opening is provided in the cover member 16 at a portion facing the cooling fan 15, and the cover member 16 and the mounting plate 17 form a substantial housing through which the cooling fan 15 can draw air.

[0026] 2 to 4, the cooling fan 15 may introduce air into the approximate housing, but may also introduce air out of the approximate housing. In the following description, the side closer to the cooling fan introducing air into the approximate housing or the side farther from the cooling fan discharging air into the approximate housing will be referred to as the "upwind side," and the side farther from the cooling fan introducing air into the approximate housing or the side closer to the cooling fan discharging air into the approximate housing will be referred to as the "downwind side." For example, among the integrated power modules 13A, 13C, and 13E on the left side of FIG. 2, the integrated power module 13A is the integrated power module 13 on the windward side, and the integrated power module 13E is the integrated power module 13 on the downwind side.

[0027] 2, in the related device, the heat sink 12 is separated into individual pieces, and one semiconductor module 18 is mounted on one heat sink 12. With this configuration, it is expected that the integrated power module 13 will be lighter in weight, more productive, easier to handle, and easier to maintain.

[0028] However, in the related device, as shown in Fig. 4, a space 29 where no heat dissipation fin 11 is provided is generated between adjacent heat dissipation fins 11 in the airflow direction. Therefore, in the related device, there is a problem that the heat dissipation area of ​​the heat dissipation fin 11 is reduced by the space 29.

[0029] Furthermore, in the related device, heat generated by the semiconductor elements 1 in the semiconductor module 18 on the windward side is transferred to the air from the heat dissipation fins 11 thermally connected to the semiconductor module 18 on the windward side, and the air tends to stagnate in the space 29. As a result, the heat of the air is transferred from the heat dissipation fins 11 thermally connected to the semiconductor module 18 on the downwind side to the semiconductor elements 1 in the semiconductor module 18 on the downwind side, preventing the semiconductor elements 1 on the downwind side from properly dissipating heat. Thus, in the related device, the semiconductor elements 1 in the semiconductor module 18 on the downwind side are susceptible to the heat generated by the semiconductor elements 1 in the semiconductor module 18 on the windward side due to the space 29, and there is a problem in that the temperature of the semiconductor elements 1 on the downwind side rises due to thermal interference.

[0030] 5 is a temperature contour diagram that schematically shows the temperature of air passing through the heat dissipation fins 11 in the related device. As shown in Fig. 5, the temperature of the air passing through the heat dissipation fins 11 increases from the upwind side to the downwind side, and the temperature reached by the semiconductor element 1 of the semiconductor module 18 on the most downwind side increases. In contrast, the power semiconductor device according to the first embodiment described below can solve the above problems.

[0031] Fig. 6 is a plan view showing the configuration of the power semiconductor device according to the first embodiment, Fig. 7 is a cross-sectional view taken along the line CC' in Fig. 6, and Fig. 8 is a plan view showing the configuration of the power semiconductor device according to the first embodiment, which corresponds to Fig. 4. Note that in Fig. 6 and subsequent figures, the reference numerals of some components are omitted to avoid complicating the drawings.

[0032] The following mainly describes the differences between the power semiconductor device according to the first embodiment and related devices. The power semiconductor device of Fig. 6 includes two heat sinks 12 (heat sinks 12A and 12B) and six semiconductor modules 18 (semiconductor modules 18A to 18F in Fig. 6). The heat sinks 12A and 12B are arranged in a direction intersecting the airflow direction of the cooling fan 15, and in the example of Fig. 6, the heat sinks 12A and 12B are arranged in a direction perpendicular to the airflow direction.

[0033] In the first embodiment, the three semiconductor modules 18 are arranged along the airflow direction of the cooling fan 15 and mounted on one heat sink 12. That is, the three semiconductor modules 18 are mounted on one heat sink 12 while being arranged in the same direction as or substantially the same as the airflow direction of the cooling fan 15. In the example of Fig. 6, the left semiconductor modules 18A, 18C, and 18E are mounted on the left heat sink 12A while being arranged in the same direction as or substantially the same as the airflow direction of the cooling fan 15. Furthermore, the right semiconductor modules 18B, 18D, and 18F are mounted on the right heat sink 12B while being arranged in the same direction as or substantially the same as the airflow direction of the cooling fan 15.

[0034] Instead of three semiconductor modules 18, two or four or more semiconductor modules 18 may be mounted on one heat sink 12, arranged along the airflow direction of the cooling fan 15. In other words, it is sufficient that the multiple semiconductor modules 18 are mounted on one heat sink 12, arranged in the same direction as the airflow direction of the cooling fan 15 or in substantially the same direction.

[0035] In the first embodiment, as shown in FIG. 6, the heat sink base 10 of the heat sink 12 extends along the direction of airflow from the cooling fan 15 .

[0036] 6 and 8, in the first embodiment, the heat dissipation fins 11 of the heat sink 12 extend continuously across three semiconductor modules 18 adjacent to each other in the airflow direction in a plan view. In the example of FIGS. 6 and 8, the heat dissipation fins 11 of the heat sink 12A extend continuously across the semiconductor modules 18A, 18C, and 18E adjacent to each other in the airflow direction in a plan view. Furthermore, the heat dissipation fins 11 of the heat sink 12B extend continuously across the semiconductor modules 18B, 18D, and 18F adjacent to each other in the airflow direction in a plan view. Although the number of heat sinks 12 is two in the first embodiment, it may be one.

[0037] The power semiconductor device according to the first embodiment configured as described above does not have any spaces 29 where the heat dissipation fins 11 are not provided, as shown in FIG. 4 , thereby improving the heat dissipation performance of the heat sink 12. The width of the heat sink base 10, i.e., the dimension perpendicular to the airflow direction of the cooling fan 15, is determined by the external size of the power semiconductor device. Therefore, if the external size of the power semiconductor device according to the first embodiment is the same as that of a related device, the heat dissipation performance of the heat sink 12 can be improved compared to that of the related device. Furthermore, if the width of the heat sink base 10 according to the first embodiment is the same as that of the heat sink base 10 of the related device, the heat sink base 10 according to the first embodiment can be manufactured by using the same extrusion die as that of the heat sink base 10 of the related device but changing the extrusion length.

[0038] Furthermore, in the first embodiment, the three semiconductor modules 18 across which the heat dissipation fins 11 extend include the semiconductor module 18 on the most downstream side of the cooling fan 15 (semiconductor module 18E or semiconductor module 18F in the examples of FIGS. 6 and 8). This configuration can improve the heat dissipation performance of the heat sink 12 in the semiconductor modules 18E and 18F. However, this is not essential in cases where the amount of heat generated by the semiconductor modules 18E and 18F is smaller than the amount of heat generated by the semiconductor modules 18A to 18D.

[0039] The above-described effects can also be obtained with a configuration in which each semiconductor module 18 in the configuration in Fig. 6 is rotated 90°, as shown in Fig. 9. Furthermore, the number of semiconductor modules 18 over which the heat dissipation fins 11 extend is not limited to three, and may be two or four or more. In other words, it is sufficient that the heat dissipation fins 11 of the heat sink 12 extend continuously over two or more adjacent semiconductor modules 18 in the airflow direction in a plan view.

[0040] 10 is a cross-sectional view showing a method for manufacturing a power semiconductor device according to the first embodiment. First, a semiconductor module 18 in which a semiconductor element 1, a metal conductor 4, a fin base 9, etc. are integrated with a sealing member 8, and a heat sink 12 are prepared. Next, the heat sink 12 is mounted on a crimping blade unit 32, which is a jig capable of accommodating the heat dissipation fins 11 of the heat sink 12, while the heat dissipation fins 11 are accommodated in the crimping blade unit 32.

[0041] Next, the first uneven portion 9a of the fin base 9 of the semiconductor module 18 is aligned with the second uneven portion 12a of the heat sink 12 mounted on the crimping blade unit 32. Thereafter, the semiconductor module 18 is pressed in the direction of arrow 31 to fit the first uneven portion 9a with the second uneven portion 12a, thereby integrating the fin base 9 and the heat sink 12. In parallel with the above steps, the mounting plate 17 is mounted and fixed to the cover member 16. Then, the heat sink base 10 of the heat sink 12 integrated with the fin base 9 of the semiconductor module 18 is mounted and fixed to the mounting plate 17. As a result of the above, a power semiconductor according to the first embodiment can be manufactured in which the heat dissipation properties of the heat sink 12 are improved.

[0042] <Second Preferred Embodiment> Fig. 11 is a plan view showing the configuration of a power semiconductor device according to a second preferred embodiment, and Fig. 12 is a cross-sectional view taken along line DD' in Fig. 11. Fig. 13 is a plan view showing the configuration of a power semiconductor device according to the second preferred embodiment, and corresponds to Fig. 8.

[0043] In the first embodiment, as shown in FIG. 7, a relatively large space exists between the heat dissipation fins 11 of the heat sink 12A and the heat dissipation fins 11 of the heat sink 12B, so the cross-sectional area of ​​the air passage of the cooling fan 15 is relatively large.

[0044] 11 to 13, in the second embodiment, air-path forming members 30, which are structural auxiliary members, are provided between adjacent heat sinks 12 and between the mounting plate 17 and the cover member 16. With this configuration, the cross-sectional area of ​​the air path of the cooling fan 15 can be reduced, thereby increasing the airflow speed in the heat dissipation fins 11. As a result, the heat transfer coefficient of the heat dissipation fins 11 can be increased, thereby improving the heat dissipation performance of the heat sink and reducing the temperature reached by the semiconductor element 1.

[0045] Furthermore, when the integrated power module 13 (i.e., the semiconductor module 18 and the heat sink 12) is mounted on the mounting plate 17, the mounting plate 17 may bend due to the weight of the integrated power module 13. If the mounting plate 17 is bent, displacement due to vibration during use of the product increases, which may cause the screws and other fastening members that fasten the various components to become loose. However, if the mounting plate 17 is made thicker to solve this problem, another problem arises in that the weight of the power semiconductor device increases.

[0046] Air-path forming member 30 according to the second embodiment not only reduces the cross-sectional area of ​​the air path of cooling fan 15, but also functions as a support member for mounting plate 17, thereby suppressing deflection of mounting plate 17. Note that at least a portion of air-path forming member 30 may be an elastic member having elasticity. With this configuration, mounting plate 17 can be fixed to cover member 16 with surface pressure applied, thereby enhancing the function of suppressing deflection of mounting plate 17.

[0047] 11 to 13, the air-path forming member 30 extends uniformly and continuously along the airflow direction, but this is not limiting. FIG. 14 is a plan view showing the configuration of a power semiconductor device according to the second embodiment, and FIGS. 15, 16, and 17 are cross-sectional views taken along lines E-E', F-F', and G-G' in FIG. 14, respectively. FIG. 18 is a plan view showing the configuration of a power semiconductor device according to the second embodiment, and corresponds to FIG. 8. As shown in FIGS. 14 to 18, the air-path forming member 30 may be provided corresponding to the semiconductor modules 18E and 18F on the most downstream side of the cooling fan 15. In other words, the air-path forming member 30 may be provided only across the semiconductor modules 18E and 18F.

[0048] With this configuration, the airflow speed at the heat dissipation fins 11 of the semiconductor modules 18E, 18F on the most downwind side can be increased. Also, air that passes through the front side of the air-path forming member 30 without passing through the heat dissipation fins 11 of the semiconductor modules 18A to 18D, i.e., air whose temperature increase is suppressed, can be made to flow into the heat dissipation fins 11 of the semiconductor modules 18E, 18F on the most downwind side. This makes it possible to improve the heat dissipation performance of the heat sinks 12 in the semiconductor modules 18E, 18F compared to the heat dissipation performance of the heat sinks 12 in the semiconductor modules 18A to 18D.

[0049] Here, for example, in a configuration in which the currents flowing through the semiconductor modules 18A to 18F are substantially the same and the heat generation amounts of the semiconductor modules 18A to 18F are substantially the same, excluding differences due to manufacturing variations, the temperature reached by the semiconductor modules 18E, 18F on the most downwind side will be the highest. For such a configuration, it is particularly effective to increase the heat dissipation performance of the heat sinks 12 in the semiconductor modules 18E, 18F on the most downwind side as described above compared to the heat dissipation performance of the heat sinks 12 in the semiconductor modules 18A to 18D. Note that, although one air path forming member 30 is provided in the above description, multiple air path forming members 30 may also be provided.

[0050] <Third Preferred Embodiment> Fig. 19 is a plan view showing the configuration of a power semiconductor device according to a third preferred embodiment, and Figs. 20 and 21 are cross-sectional views taken along lines H-H' and II', respectively, in Fig. 19. Fig. 22 is a plan view showing the configuration of a power semiconductor device according to the third preferred embodiment, and corresponds to Fig. 8.

[0051] As shown in Figure 19, in this third embodiment, one semiconductor module 18 (semiconductor module 18A or semiconductor module 18B in the example of Figure 19) is mounted on one heat sink 12 (heat sink 12C or heat sink 12D in the example of Figure 19).

[0052] Two semiconductor modules 18 arranged along the airflow direction of the cooling fan 15 are mounted on one heat sink 12. In the example of Fig. 19, semiconductor modules 18C and 18E arranged along the airflow direction are mounted on one heat sink 12E, and semiconductor modules 18D and 18F arranged along the airflow direction are mounted on one heat sink 12F.

[0053] 19 and 22, in the third embodiment, the heat dissipation fins 11 of the heat sink 12 extend continuously across two semiconductor modules 18 adjacent to each other in the airflow direction in a plan view. In the example of Fig. 19 and 22, the heat dissipation fins 11 of the heat sink 12E extend continuously across the semiconductor modules 18C and 18E adjacent to each other in the airflow direction in a plan view. Furthermore, the heat dissipation fins 11 of the heat sink 12F extend continuously across the semiconductor modules 18D and 18F adjacent to each other in the airflow direction in a plan view.

[0054] According to this configuration, the heat dissipation performance of the heat sink 12 can be improved compared to the related device, as in the case of embodiment 1. Furthermore, compared to embodiment 1, it is expected that the integrated power module 13 will be smaller, lighter, more productive, easier to handle, and easier to maintain.

[0055] In the third embodiment, the two semiconductor modules 18 across which the heat dissipation fins 11 extend include the semiconductor module 18 (semiconductor module 18E or semiconductor module 18F in the examples of FIGS. 19 and 22) that is furthest downwind from the cooling fan 15. This configuration can improve the heat dissipation performance of the heat sink 12 in the semiconductor modules 18E and 18F.

[0056] 23 , the semiconductor module 18 on the windward side (semiconductor module 18A or semiconductor module 18B in the example of FIG. 23 ) and the semiconductor module 18 adjacent to them in the direction of the airflow of the cooling fan 15 (semiconductor module 18C or semiconductor module 18D in the example of FIG. 23 ) may be mounted on a single heat sink 12 (heat sink 12C or heat sink 12D in the example of FIG. 23 ). The remaining semiconductor module (semiconductor module 18E or semiconductor module 18F in the example of FIG. 23 ) may be mounted on a single heat sink (heat sink 12E or heat sink 12F in the example of FIG. 23 ). The configuration as shown in FIG. 20 is most effective when, for example, the amount of heat generated by the semiconductor modules 18E and 18F on the windward side is smaller than the amount of heat generated by the other semiconductor modules.

[0057] 24 to 26, the air-path forming member 30 described in the second embodiment with reference to FIGS. 11 to 13 may be provided in the power semiconductor device of the third embodiment. With such a configuration, it is possible to reduce the temperature reached by the semiconductor element 1 and suppress the bending of the mounting plate 17.

[0058] 27 to 30, the air-passage forming member 30 described in the second embodiment with reference to FIGS. 14 to 18 may be provided in the power semiconductor device of the third embodiment. With such a configuration, the heat dissipation performance of the heat sink 12 in the semiconductor modules 18E and 18F can be made higher than the heat dissipation performance of the heat sink 12 in the semiconductor modules 18A to 18D.

[0059] Fourth Preferred Embodiment FIG. 31 is a plan view showing the configuration of a power semiconductor device according to a fourth preferred embodiment, and FIG. 32 is a cross-sectional view taken along line MM' in FIG.

[0060] 32 , in the fourth embodiment, an air-path regulating member 37 that regulates the air path of the cooling fan 15 is provided on the opposite side of the heat dissipation fins 11 from the semiconductor module 18. In the example of FIG. 32 , the air-path regulating member 37 is provided as a part of the cover member 16, but it may be provided as a separate member from the cover member 16.

[0061] 32, the cross-sectional area of ​​the air path defined by air-path regulating member 37 on the downwind side of cooling fan 15 is smaller than the cross-sectional area of ​​the air path defined by air-path regulating member 37 on the upwind side of cooling fan 15. In the example of Fig. 32, the cross-sectional area is continuously reduced by air-path regulating member 37 from just before semiconductor module 18A on the upwind side to just before semiconductor module 18E on the downwind side.

[0062] With this configuration, not only air from the heat dissipation fins 11 on the lower side of the semiconductor modules 18A and 18C as indicated by arrow 39, but also air whose temperature has barely increased as indicated by arrow 38 can flow into the heat dissipation fins 11 on the lower side of the semiconductor module 18E. Therefore, the heat dissipation performance of the heat sink 12 in the semiconductor module 18E can be improved compared to the heat dissipation performance of the heat sink 12 in the semiconductor modules 18A and 18C.

[0063] In the example of FIG. 32, the cross-sectional area of ​​the air passage defined by the air passage defining member 37 decreases continuously from the upwind side to the downwind side of the cooling fan 15, but it may also decrease in stages.

[0064] As shown in Figure 33, by providing a notch in the heat dissipation fin 11, the height of the heat dissipation fin 11 on the downwind side of the cooling fan 15 may be greater than the height of the heat dissipation fin 11 on the upwind side of the cooling fan 15.

[0065] Even with this configuration, the heat dissipation performance of the heat sink 12 in the semiconductor module 18E can be improved compared to the heat dissipation performance of the heat sink 12 in the semiconductor modules 18A and 18C, as in the case of Fig. 32. In the example of Fig. 33, the height of the heat dissipation fins 11 increases stepwise from the upwind side to the downwind side of the cooling fan 15, but the height may also increase continuously. Furthermore, the second or third embodiment, rather than the first embodiment, may be applied to the fourth embodiment.

[0066] Fifth Preferred Embodiment A power conversion device according to a fifth preferred embodiment includes the power semiconductor devices according to the above-described first to fourth preferred embodiments. The power conversion device according to the fifth preferred embodiment is not limited to a specific power conversion device, but hereinafter, a case where the power conversion device according to the fifth preferred embodiment is applied to a three-phase inverter will be described.

[0067] FIG. 34 is a block diagram showing the configuration of a power conversion system to which the power conversion device according to the fifth embodiment is applied.

[0068] The power conversion system shown in Fig. 34 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 sources, and may be composed of, for example, a DC system, a solar cell, or a storage battery, or may be composed of a rectifier circuit or an AC / DC converter connected to an AC system. The power supply 100 may also be composed of a DC / DC converter that converts DC power output from a DC system into a predetermined power.

[0069] The power conversion device 200 is a three-phase inverter connected between the power source 100 and the load 300, and 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. 34 , the power conversion device 200 includes a main conversion circuit 201 that converts input DC power into AC power and outputs it, and a control circuit 203 that outputs a control signal to the main conversion circuit 201 to control the main conversion circuit 201.

[0070] The load 300 is a three-phase electric motor driven by AC power supplied from the power conversion device 200. The load 300 is not limited to a specific application, but is an electric motor mounted on various electrical devices, and is used as an electric motor for, for example, a hybrid vehicle, an electric vehicle, a railroad car, an elevator, or an air conditioning device.

[0071] The power conversion device 200 will be described in detail below. The main conversion circuit 201 includes switching elements and freewheel diodes (not shown). The switching elements convert DC power supplied from the power source 100 into AC power, which is supplied to the load 300. The main conversion circuit 201 can have a variety of specific circuit configurations. The main conversion circuit 201 according to the fifth embodiment is a two-level, three-phase full-bridge circuit, which can be configured with six switching elements and six freewheel diodes connected in anti-parallel to each switching element. Each switching element of the main conversion circuit 201 is configured using the power semiconductor device 202 according to the first to fourth embodiments. Two of the six switching elements are connected in series to form upper and lower arms, which constitute each phase (U phase, V phase, and 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.

[0072] The main conversion circuit 201 includes a drive circuit (not shown) that drives each switching element. The drive circuit may be built into the power semiconductor device 202, or may be provided separately from the power semiconductor device 202. The drive circuit generates drive signals that drive 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, the drive circuit outputs a drive signal that turns the switching element on and a drive signal that turns the switching element off to the control electrodes of each switching element in accordance with a control signal from a control circuit 203 (described later). To maintain a switching element in the on state, the drive signal is a voltage signal (on signal) that is greater than the threshold voltage of the switching element, and to maintain a switching element in the off state, the drive signal is a voltage signal (off signal) that is smaller than the threshold voltage of the switching element.

[0073] The control circuit 203 controls the switching elements of the main conversion circuit 201 so that the desired power is supplied to the load 300. Specifically, the control circuit 203 calculates the time (on time) that each switching element of the main conversion circuit 201 should be in the on state based on the power to be supplied to the load 300. For example, the control circuit 203 can control the main conversion circuit 201 using PWM (Pulse Width Modulation) control, which modulates the on time of the switching elements according to the voltage to be output. The control circuit 203 then outputs a control command (control signal) to a drive circuit included 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 at each time point. In accordance with this control signal, the drive circuit outputs an on signal or an off signal as a drive signal to the control electrode of each switching element.

[0074] In the power conversion device according to the fifth embodiment as described above, the power semiconductor device 202 according to the first to fourth embodiments is applied as the switching element of the main conversion circuit 201, thereby improving reliability in terms of heat dissipation.

[0075] In the above-described fifth embodiment, an example has been described in which the power semiconductor device 202 according to any one of the first to fourth embodiments is applied to a two-level three-phase inverter. However, the fifth embodiment is not limited to this and can be applied to various power conversion devices. While the power conversion device according to the fifth embodiment has been described as a two-level power conversion device, it may be a three-level or multi-level power conversion device. In addition, when supplying power to a single-phase load, the power conversion device may be applied to a single-phase inverter. Furthermore, when supplying power to a DC load or the like, the power semiconductor device 202 may also be applied to a DC / DC converter or an AC / DC converter.

[0076] Furthermore, the power conversion device according to the fifth embodiment is not limited to the case where the load 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 contactless 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.

[0077] In this disclosure, 'a' and 'an' mean one or more. Therefore, 'a', 'an', 'one or more', and 'at least one' can be used interchangeably.

[0078] It should be noted that the embodiments and modifications may be freely combined, and the embodiments and modifications may be modified or omitted as appropriate. The above description is illustrative in all respects and is not limiting. It is understood that countless modifications not illustrated can be envisioned.

[0079] Various aspects of the present disclosure are summarized below as appendices.

[0080] a mounting plate having openings into which the heat dissipation fins are inserted and on which the remaining portions of the heat sink other than the heat dissipation fins are mounted; and a cover member on which the mounting plate is mounted and which partially covers the heat dissipation fins, wherein a first uneven portion is formed in a fin base of the semiconductor module at a portion facing the heat sink, and a second uneven portion engaged with the first uneven portion is formed in a portion of the heat sink at a portion facing the fin base, and the heat dissipation fin extends continuously across two or more of the plurality of semiconductor modules that are adjacent in the airflow direction, in a plan view, and the plurality of semiconductor modules arranged along the airflow direction include three or more of the semiconductor modules, and the two or more semiconductor modules across which the heat dissipation fins extend include the semiconductor module furthest downwind of the cooling fan.

[0081] (Supplementary Note 2) The power semiconductor device according to Supplementary Note 1, further comprising one or more structural support members provided between the heat sinks adjacent to each other in a direction intersecting the airflow direction and between the mounting plate and the cover member.

[0082] (Supplementary Note 3) The power semiconductor device according to Supplementary Note 2, wherein the one or more structural support members are one structural support member that extends uniformly along the airflow direction.

[0083] (Supplementary Note 4) The power semiconductor device according to Supplementary Note 2, wherein the one or more structural support members are provided corresponding to the semiconductor module on the most downstream side of the cooling fan.

[0084] (Supplementary Note 5) The power semiconductor device according to any one of Supplementary Notes 2 to 4, wherein at least a portion of the structural support member has elasticity.

[0085] (Appendix 6) A power semiconductor device according to any one of appendices 2 to 5, wherein an air path regulating member that defines an air path of the cooling fan is provided on the opposite side of the heat dissipation fin from the semiconductor module, and a cross-sectional area of ​​the air path defined by the air path regulating member on the downwind side of the cooling fan is smaller than a cross-sectional area of ​​the air path defined by the air path regulating member on the upwind side of the cooling fan.

[0086] (Supplementary Note 7) The power semiconductor device according to any one of Supplementary Note 1 to Supplementary Note 6, wherein a height of the heat dissipation fins on the downwind side of the cooling fan is greater than a height of the heat dissipation fins on the upwind side of the cooling fan.

[0087] (Supplementary Note 8) A power conversion device comprising: a main conversion circuit having the power semiconductor device according to any one of Supplementary Note 1 to Supplementary Note 7, which converts input power and outputs the converted power; and a control circuit which outputs a control signal for controlling the main conversion circuit to the main conversion circuit.

[0088] 9 Fin base, 9a First uneven portion, 10 Heat sink base, 11 Heat dissipation fin, 12 Heat sink, 12a Second uneven portion, 15 Cooling fan, 16 Cover member, 17 Mounting plate, 17a Opening, 18, 18A to 18F Semiconductor module, 30 Air path forming member, 32 Crimping blade unit, 37 Air path regulating member, 201 Main conversion circuit, 202 Power semiconductor device, 203 Control circuit.

Claims

1. A power semiconductor device comprising: a cooling fan; one or more heat sinks including heat dissipation fins extending in the airflow direction of the cooling fan; a plurality of semiconductor modules mounted on the heat sink and arranged in the airflow direction; an attachment plate having openings into which the heat dissipation fins are inserted and on which the remainder of the heat sink other than the heat dissipation fins is mounted; and a cover member on which the attachment plate is mounted and which partially covers the heat dissipation fins, wherein a first uneven portion is formed on a fin base of the semiconductor module in a portion facing the heat sink, and a second uneven portion engaged with the first uneven portion is formed on a portion of the heat sink facing the fin base, and in a plan view, the heat dissipation fin extends continuously across two or more of the plurality of semiconductor modules that are adjacent in the airflow direction, and the plurality of semiconductor modules arranged in the airflow direction include three or more of the semiconductor modules, and the two or more semiconductor modules across which the heat dissipation fins extend include the semiconductor module furthest downwind of the cooling fan.

2. A power semiconductor device according to claim 1, further comprising one or more structural support members provided between adjacent heat sinks in a direction intersecting the airflow direction and between the mounting plate and the cover member.

3. A power semiconductor device according to claim 2, wherein the one or more structural support members are one structural support member that extends uniformly along the wind flow direction.

4. A power semiconductor device according to claim 2, wherein said one or more structural support members are provided corresponding to said semiconductor module on the most downstream side of said cooling fan.

5. A power semiconductor device according to any one of claims 2 to 4, wherein at least a portion of the structural support member has elasticity.

6. A power semiconductor device according to any one of claims 1 to 5, wherein an air path defining member that defines the air path of the cooling fan is provided on the opposite side of the heat dissipation fin from the semiconductor module, and the cross-sectional area of ​​the air path defined by the air path defining member on the downwind side of the cooling fan is smaller than the cross-sectional area of ​​the air path defined by the air path defining member on the upwind side of the cooling fan.

7. A power semiconductor device according to any one of claims 1 to 6, wherein the height of the heat dissipation fins on the downwind side of the cooling fan is greater than the height of the heat dissipation fins on the upwind side of the cooling fan.

8. A power conversion device comprising a power semiconductor device according to any one of claims 1 to 7, a main conversion circuit that converts input power and outputs it, and a control circuit that outputs a control signal to control said main conversion circuit.

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