power module

Abstract

The power module includes: a first conductor plate on which a first power semiconductor element is bonded; a second conductor plate on which a second power semiconductor element is bonded and disposed adjacent to the first conductor plate; a first heat dissipation member disposed opposite to the first conductor plate and the second conductor plate; and a first insulating sheet member disposed between the first heat dissipation member and the first conductor plate, wherein the first power semiconductor element is disposed at a position where a first length from the end of the first conductor plate near the second conductor plate to the first power semiconductor element is greater than a second length from the end of the first conductor plate away from the second conductor plate to the first power semiconductor element, and the second length is greater than the thickness of the first conductor plate.

Description

Technical Field

[0001] This invention relates to a power module. Background Technology

[0002] Power modules, which convert power through the switching action of power semiconductor elements, are widely used in civilian, automotive, railway, and power transmission equipment due to their high conversion efficiency. Because these power semiconductor elements repeatedly generate heat during switching, high reliability is required for power modules. For example, in automotive applications, even higher reliability is required due to the demands for miniaturization and lightweight design.

[0003] Patent document 1 discloses a power module in which a conductor plate is bonded to the surface and back of a power semiconductor element, and a heat dissipation component is connected in between through an insulating layer, so that the heat generated by the power semiconductor element is conducted from the conductor plate to the heat dissipation component through the insulating layer.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-113343 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] The components within the power module repeatedly expand and contract due to the repeated heating of the power semiconductor elements, causing the insulation layer (insulating sheet component) between the conductor plate and the heat dissipation component to peel off, thus reducing the heat dissipation performance of the power module.

[0009] Technical means to solve the problem

[0010] The power module of the present invention includes: a first power semiconductor element and a second power semiconductor element; a first conductor plate for bonding the first power semiconductor element; a second conductor plate for bonding the second power semiconductor element and disposed adjacent to the first conductor plate; a first heat dissipation member disposed opposite to the first conductor plate and the second conductor plate; and a first insulating sheet member disposed between the first heat dissipation member and the first conductor plate. In a cross section passing through the center of the first power semiconductor element and the center of the second power semiconductor element and perpendicular to the bonding surface of the first conductor plate and the first power semiconductor element, the first power semiconductor element is disposed at a position where a first length from the end of the first conductor plate near the second conductor plate to the first power semiconductor element is greater than a second length from the end of the first conductor plate away from the second conductor plate to the first power semiconductor element, wherein the second length is greater than the thickness of the first conductor plate.

[0011] The power module of the present invention includes: a first power semiconductor element and a second power semiconductor element; a first conductor plate to which the first power semiconductor element is joined; a second conductor plate to which the second power semiconductor element is joined and disposed adjacent to the first conductor plate; a first heat dissipation member disposed opposite to the first conductor plate and the second conductor plate; and a first insulating sheet member disposed between the first heat dissipation member and the first conductor plate. In a cross-section passing through the center of the first power semiconductor element and the center of the second power semiconductor element, perpendicular to the joint surface of the first conductor plate and the first power semiconductor element, the center of the first power semiconductor element is positioned closer to the end of the first conductor plate on the side away from the second conductor plate than the end of the first conductor plate on the side closer to the second conductor plate, and the length from the end of the first conductor plate on the side away from the second conductor plate to the first power semiconductor element is greater than the thickness of the first conductor plate. The center of the second power semiconductor element is positioned closer to the end of the second conductor plate on the side away from the first conductor plate than the end of the second conductor plate on the side closer to the first conductor plate, and the length from the end of the second conductor plate on the side away from the first conductor plate to the second power semiconductor element is greater than the thickness of the second conductor plate.

[0012] The effects of the invention

[0013] According to the present invention, it is possible to prevent the insulating sheet components from peeling off and maintain the heat dissipation performance of the power module. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view of the metal casing of the first embodiment.

[0015] Figure 2 This is a cross-sectional view of the semiconductor module according to the first embodiment.

[0016] Figure 3 This is a top view of the power module in the first embodiment.

[0017] Figure 4 This is a cross-sectional view of the power module in the first embodiment.

[0018] Figure 5 This is a cross-sectional view of the power module in the second embodiment.

[0019] Figure 6 This is a cross-sectional view of the power module in the third embodiment. Detailed Implementation

[0020] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following description and drawings are examples for illustrating the present invention; appropriate omissions and simplifications have been made for clarity. The present invention may also be implemented in various other ways. Unless otherwise specified, the constituent elements may be singular or plural.

[0021] To facilitate understanding of the present invention, the positions, sizes, shapes, and extents of the constituent elements shown in the accompanying drawings may not represent their actual positions, sizes, shapes, or extents. Therefore, the present invention is not limited to the positions, sizes, shapes, and extents disclosed in the accompanying drawings.

[0022] [First Implementation Method]

[0023] Hereinafter, this embodiment will be described with reference to the accompanying drawings.

[0024] Figure 1 This is a cross-sectional view of the metal housing 40 that houses the semiconductor module 30. The power module 100, described later, is constructed by housing the semiconductor module 30 within the metal housing 40.

[0025] like Figure 1 As shown, the metal casing 40 is composed of a first heat dissipation component 7, a second heat dissipation component 8, and a frame 20. Multiple heat dissipation fins 7a are provided on the surface of the first heat dissipation component 7. Multiple heat dissipation fins 8a are provided on the surface of the second heat dissipation component 8.

[0026] The first heat dissipation component 7 and the second heat dissipation component 8 are joined to the frame 20 at their respective peripheral ends 7b and 8b. The joining can be achieved, for example, by using FSW (friction stir bonding), laser welding, brazing, etc. By using a metal housing 40 of this shape, even if the power module 100 is placed in a flow path for refrigerants such as water, oil, or organic matter, it is possible to prevent the cooling medium from entering the interior of the power module 100.

[0027] In this embodiment, the first heat dissipation component 7, the second heat dissipation component 8, and the frame 20 are shown as different components, but the first heat dissipation component 7, the second heat dissipation component 8, and the frame 20 can be the same component or they can be integrated.

[0028] Details of the metal casing 40 are described later. Figure 3 As shown, the metal casing 40 is, for example, a flat, cylindrical cooler with an insertion port 100a on one side and a bottom on the other side. The metal casing 40 is formed of conductive components, such as composite materials like Cu, Cu alloys, Cu-C, Cu-CuO, or composite materials like Al, Al alloys, AlSiC, Al-C.

[0029] Figure 2 This is a cross-sectional view of semiconductor module 30.

[0030] like Figure 2 As shown, a first conductor plate 3 for bonding a first power semiconductor element 1 and a second conductor plate 13 for bonding a second power semiconductor element 11 are arranged adjacent to each other. The first power semiconductor element 1 is bonded to the first conductor plate 3 by a bonding material 2a. The second power semiconductor element 11 is bonded to the second conductor plate 13 by a bonding material 12a.

[0031] Furthermore, a third conductor plate 4 is bonded to the side of the first power semiconductor element 1 opposite to the side to which the first conductor plate 3 is bonded, via a bonding material 2b. Each electrode on both sides of the first power semiconductor element 1 has a structure in which it is held by the first conductor plate 3 and the third conductor plate 4, which are arranged opposite to each electrode surface.

[0032] The second power semiconductor element 11 has a fourth conductor plate 14 bonded to its side opposite to the side where the second conductor plate 13 is bonded, via a bonding material 12b. Each electrode of the second power semiconductor element 11 has a structure in which it is held by the second conductor plate 13 and the fourth conductor plate 14, which are arranged opposite to their respective electrode surfaces.

[0033] The semiconductor module 30 is constructed by sealing a first power semiconductor element 1, a second power semiconductor element 11, a first conductor plate 3, a second conductor plate 13, a third conductor plate 4, and a fourth conductor plate 14 with a first sealing resin 9. The first sealing resin 9 exposes the surfaces 3a of the first conductor plate 3, 13a of the second conductor plate 13, 4a of the third conductor plate 4, and 14a of the fourth conductor plate 14 on the surface of the semiconductor module 30, covering the rest of the module. One surface of the semiconductor module 30 is flush with the surfaces 3a of the first conductor plate 3 and 13a of the second conductor plate 13. Furthermore, another surface of the semiconductor module 30 is flush with the surfaces 4a of the third conductor plate 4 and 14a of the fourth conductor plate 14.

[0034] The first conductor plate 3, the second conductor plate 13, the third conductor plate 4, and the fourth conductor plate 14 are formed, for example, of copper, copper alloys, or aluminum, aluminum alloys, etc. Although in Figure 2 The term is omitted, but in reality, wires are connected and wired on the first conductor plate 3, the second conductor plate 13, the third conductor plate 4, and the fourth conductor plate 14 as needed, or wires are integrally formed.

[0035] Figure 3 This is a top view of the power module 100 in this embodiment.

[0036] Power module 100 in Figure 1 The metal casing 40 shown contains Figure 2 It is composed of the semiconductor module 30 shown.

[0037] The metal housing 40 is a flat, cylindrical shape with a flange 21 on one side and a bottom on the other. An insertion port 100a is provided on the surface of the flange 21, through which a semiconductor module 30 is inserted. Terminals 33 and 34, which connect to the internal semiconductor module 30, extend from the insertion port 100a. A first heat dissipation member 7 engages with the frame 20 of the metal housing 40 at its peripheral end 7b. Multiple heat sinks 7a are provided on the surface of the first heat dissipation member 7, through which refrigerant (not shown) flows to cool the power module 100.

[0038] Figure 4 yes Figure 3 The power module 100 shown is a cross-sectional view along line A-A'. This cross-sectional view along line A-A' is a cross-sectional view passing through the center of the first power semiconductor element 1 and the center of the second power semiconductor element 11.

[0039] like Figure 4 As shown, a first insulating sheet component 5 and a second insulating sheet component 6 with high thermal conductivity are respectively sandwiched between the semiconductor module 30 and the first heat dissipation component 7 and the second heat dissipation component 8 on both sides. The first insulating sheet component 5 and the second insulating sheet component 6 are used to conduct heat generated from the semiconductor module 30 to the first heat dissipation component 7 and the second heat dissipation component 8, and are formed of materials with high thermal conductivity and high insulation withstand voltage. For example, insulating sheets, insulating layers or adhesives containing micro powders such as alumina (bauxite), aluminum nitride, carbon, etc. are used.

[0040] like Figure 2 As shown, the exposed surfaces 3a of the first conductor plate 3 and 13a of the second conductor plate 13 on both sides of the semiconductor module 30 are as follows: Figure 4 As shown, it is joined with the first insulating sheet member 5. The surface of the first insulating sheet member 5 opposite to the surface of the first conductor plate 3 and the second conductor plate 13 is joined with the first heat dissipation member 7 in a manner that allows heat conduction from the first conductor plate 3 and the second conductor plate 13 to the first heat dissipation member 7.

[0041] In addition, such as Figure 2 As shown, the third conductor plate 4, surface 4a, and the fourth conductor plate 14, surface 14a, exposed on both sides of the semiconductor module 30, are as follows: Figure 4 As shown, it is joined with the second insulating sheet member 6. The surface of the second insulating sheet member 6 opposite to the surface of the third conductor plate 4 and the fourth conductor plate 14 is joined with the second heat dissipation member 8 in a manner that allows heat conduction from the third conductor plate 4 and the fourth conductor plate 14 to the second heat dissipation member 8.

[0042] The metal housing 40 of the power module 100 is bonded to the semiconductor module 30 through the first insulating sheet member 5 and the second insulating sheet member 6, but other gaps are filled by the second sealing resin 10. The power module 100 is described as a double-sided cooling type, but it can also be a single-sided cooling type.

[0043] Here, in the power module 100 of this embodiment, the cross-section passing through the center of the first power semiconductor element 1 and the center of the second power semiconductor element 11, perpendicular to the junction surface of the first conductor plate 3 and the first power semiconductor element 1, i.e. Figure 4 In the cross-section shown, the first power semiconductor element 1 is positioned at a location where a first length L1 from the end 3b of the first conductor plate 3 near the second conductor plate 13 to the first power semiconductor element 1 is greater than a second length L2 from the end 3c of the first conductor plate 3 away from the second conductor plate 13 to the first power semiconductor element 1. Furthermore, the second length L2 is greater than the thickness T1 of the first conductor plate 3. The first conductor plate 3 is flat, with ends 3b and 3c at its two ends. The first power semiconductor element 1 is also flat, and the distance from one end of it to the end 3b of the first conductor plate 3 is the first length L1. The distance from the other end of the first power semiconductor element 1 to the end 3c of the first conductor plate 3 is the second length L2.

[0044] Furthermore, in the cross-section passing through the center of the first power semiconductor element 1 and the center of the second power semiconductor element 11, perpendicular to the junction surface of the second conductor plate 13 and the second power semiconductor element 11, i.e. Figure 4 In the cross-section shown, the second power semiconductor element 11 is positioned at a location where the fourth length L4 from the end 13b of the second conductor plate 13 near the first conductor plate 3 to the second power semiconductor element 11 is greater than the fifth length L5 from the end 13c of the second conductor plate 13 away from the first conductor plate 3 to the second power semiconductor element 11. Furthermore, the fifth length L5 is greater than the thickness T2 of the second conductor plate 13. Additionally, the thickness T2 of the second conductor plate 13 can be the same as the thickness T1 of the first conductor plate 3, or it can be a different thickness. The second conductor plate 13 is flat, with end 13b and end 13c at its two ends. The second power semiconductor element 11 is also flat, with the distance from one end of it to end 13b of the second conductor plate 13 being the fourth length L4. The distance from the other end of the second power semiconductor element 11 to end 13c of the second conductor plate 13 is the fifth length L5.

[0045] The first power semiconductor element 1 and the second power semiconductor element 11 repeatedly switch on and off. When the first power semiconductor element 1 and the second power semiconductor element 11 generate heat, the heat is conducted to the first conductor plate 3 and the second conductor plate 13, respectively, and then conducted to the first heat dissipation member 7 via the first insulating sheet member 5, dissipating heat to the outside.

[0046] When the first heat dissipation component 7 is cooled by a cooling medium, the internal temperature of the power module 100 rises due to the heat generated by the first power semiconductor element 1 and the second power semiconductor element 11, resulting in a temperature distribution. The first power semiconductor element 1 and the second power semiconductor element 11, as heat-generating elements, have the highest temperatures, decreasing in the order of the first conductor plate 3 and the second conductor plate 13, the first insulating sheet component 5, and the first heat dissipation component 7. Furthermore, as the temperatures of the first power semiconductor element 1 and the second power semiconductor element 11 rise, each component undergoes elongation deformation. Due to the difference in deformation between the first conductor plate 3 and the second conductor plate 13 and the first heat dissipation component 7, thermal stress is generated on the first insulating sheet component 5, causing it to peel off and reducing the heat dissipation performance of the power module 100. In particular, with the increasing demand for miniaturization and weight reduction of the power module 100, future efforts to increase the density of the power module 100 will lead to increased heat generation from the power semiconductor elements and a rise in the internal temperature of the power module 100.

[0047] Assume that the first power semiconductor element 1 is disposed at the center of the first conductor plate 3 at a position L1 = L2, and the second power semiconductor element 11 is disposed at the center of the second conductor plate 13 at a position L4 = L5. In this case, when the first power semiconductor element 1 heats up, the temperature of the end 3b of the first conductor plate 3 on the second conductor plate 13 side becomes the same as the temperature of the end 3c of the first conductor plate 3 away from the second conductor plate 13 side. However, since the first conductor plate 3 and the second conductor plate 13 are disposed adjacent to each other, the temperature of the end 3b of the first conductor plate 3 on the second conductor plate 13 side is affected not only by the heat of the first power semiconductor element 1 but also by the heat of the second power semiconductor element 11. Therefore, the temperature of the end 3b of the first conductor plate 3 on the second conductor plate 13 side is higher than the temperature of the end 3c of the first conductor plate 3 away from the second conductor plate 13 side. In addition, due to the requirements of miniaturization and weight reduction of the power module 100, the lengths L1, L2, L4, and L5 cannot be increased. As a result, the higher the temperature of the first conductor plate 3 to which the first insulating sheet member 5 is joined, the greater the thermal stress generated on the first insulating sheet member 5. Therefore, the thermal stress of the first insulating sheet member 5 at the end 3b on the side of the second conductor plate 13 of the first conductor plate 3 becomes higher than that of the first insulating sheet member 5 at the end 3c of the first conductor plate 3, making it easier for peeling to occur on the first insulating sheet member 5.

[0048] However, as in this embodiment, by positioning the first power semiconductor element 1 at a position where L1 > L2, even if the temperature rise caused by the heating of the second power semiconductor element 11 is added to the temperature rise caused by the heating of the first power semiconductor element 1, the temperature of the end 3b of the first conductor plate 3 will not rise excessively compared to the temperature of the end 3c of the first conductor plate 3 on the side away from the second conductor plate 13. Therefore, the increase in thermal stress of the first insulating sheet member 5 near the end 3b on the second conductor plate 13 side of the first conductor plate 3 can be suppressed. Thus, during power cycles where the first power semiconductor element 1 repeatedly heats up, the thermal stress repeatedly generated on the first insulating sheet member 5 near the end 3b on the second conductor plate 13 side of the first conductor plate 3 can be reduced, thereby improving the lifespan relative to power cycles.

[0049] Furthermore, as in this embodiment, by positioning the second power semiconductor element 11 at a position where L4 > L5, even if the temperature rise caused by the heating of the second power semiconductor element 1 is added to the temperature rise caused by the heating of the first power semiconductor element 1, the temperature of the end 13b of the second conductor plate 13 will not rise excessively compared to the temperature of the end 13c of the second conductor plate 13 on the side away from the first conductor plate 3. This suppresses the increase in thermal stress of the first insulating sheet member 5 near the end 13b on the first conductor plate 3 side of the second conductor plate 13. Therefore, during power cycles where the first power semiconductor element 1 repeatedly heats up, the thermal stress repeatedly generated on the first insulating sheet member 5 near the end 13b on the first conductor plate 3 side of the second conductor plate 13 can be reduced, thereby improving the lifespan relative to power cycles.

[0050] In this embodiment, the configuration of the first power semiconductor element 1 and the first conductor plate 3, as well as the second power semiconductor element 11 and the second conductor plate 13, has been described as an example. However, the configuration of the first power semiconductor element 1 and the third conductor plate 4, as well as the second power semiconductor element 11 and the fourth conductor plate 14, can also be configured as described below.

[0051] like Figure 4As shown, in a cross-section passing through the center of the first power semiconductor element 1 and the center of the second power semiconductor element 11, perpendicular to the bonding surface of the first conductor plate 3 and the first power semiconductor element 1, the first power semiconductor element 1 is positioned at a position where the first length L1' from the end 4b of the third conductor plate 4 near the fourth conductor plate 14 to the end 4d of the third conductor plate 4 on the side bonding with the first power semiconductor element 1, which is closer to the fourth conductor plate 14, is greater than the second length L2' from the end 4c of the third conductor plate 4 away from the fourth conductor plate 14 to the end 4e of the third conductor plate 4 on the side bonding with the first power semiconductor element 1, which is farther from the fourth conductor plate 14. Furthermore, the second length L2' is greater than the thickness T3 of the third conductor plate 4.

[0052] Furthermore, in a cross-section passing through the center of the first power semiconductor element 1 and the center of the second power semiconductor element 11, perpendicular to the bonding surface of the second conductor plate 13 and the second power semiconductor element 11, the second power semiconductor element 11 is positioned such that a fourth length L4' from the end 14b of the fourth conductor plate 14 near the third conductor plate 4 to the end 14d of the fourth conductor plate 14 bonded to the second power semiconductor element 11 is greater than a fifth length L5' from the end 14c of the fourth conductor plate 14 away from the third conductor plate 4 to the end 14e of the fourth conductor plate 14 bonded to the second power semiconductor element 11. Additionally, the fifth length L5' is greater than the thickness T4 of the fourth conductor plate 14.

[0053] In this embodiment, an example is described where the first power semiconductor element 1 is positioned at L1 > L2 and the second power semiconductor element 11 is positioned at L4 > L5. However, the elements may also be configured based on the center positions of the first power semiconductor element 1 and the second power semiconductor element 11, as described below.

[0054] In a cross-section passing through the center of the first power semiconductor element 1 and the center of the second power semiconductor element 11, perpendicular to the junction surface of the first conductor plate 3 and the first power semiconductor element 1, the center of the first power semiconductor element 1 is positioned closer to the end 3c of the first conductor plate 3 on the side away from the second conductor plate 13 than the end 3b on the side closer to the second conductor plate 13. That is, as Figure 4As shown, the length M11 between the center of the first power semiconductor element 1 and the end 3b of the first conductor plate 3 is longer than the length M12 between the center of the first power semiconductor element 1 and the end 3c of the first conductor plate 3. Moreover, the length L2 from the end 3c of the first conductor plate 3 away from the second conductor plate 13 to the first power semiconductor element 1 is greater than the thickness T1 of the first conductor plate.

[0055] Furthermore, the center of the second power semiconductor element 11 is positioned closer to the end 13c of the second conductor plate 13 on the side away from the first conductor plate 3 than the end 13b on the side closer to the first conductor plate 3. That is, as Figure 4 As shown, the length M14 between the center of the second power semiconductor element 11 and the end 13b of the second conductor plate 13 is longer than the length M15 between the center of the second power semiconductor element 11 and the end 13c of the second conductor plate 13. Furthermore, the length L5 from the end 13c of the second conductor plate 13 on the side furthest from the first conductor plate 3 to the second power semiconductor element 11 is greater than the thickness T2 of the second conductor plate 13.

[0056] According to this embodiment, the peeling of the first insulating sheet member 5 and the second insulating sheet member 6 can be prevented, and the heat dissipation performance of the power module 100 can be maintained, thus providing a highly reliable power module 100.

[0057] [Second Implementation]

[0058] Figure 5 This is a cross-sectional view of the power module 100 according to the second embodiment. Figure 1 The cross-sectional view of the metal casing 40 shown. Figure 3 The top view of the power module 100 shown is the same in this embodiment.

[0059] In a first embodiment, an example is shown of a power module 100 in which a first power semiconductor element 1 and a second power semiconductor element 2 are bonded to adjacent first conductor plates 3 and second conductor plates 13 respectively by bonding materials 2a and 12a. In this embodiment, as Figure 5 As shown, a double-sided cooled power module 100 with multiple power semiconductor elements arranged on adjacent conductor plates 3 and 13 will be described as an example.

[0060] The first conductor plate 3 and the second conductor plate 13 are arranged adjacent to each other. The first power semiconductor element 1a and the third power semiconductor element 1b are bonded to the first conductor plate 3 by bonding material 2a. The second power semiconductor element 11a and the fourth power semiconductor element 11b are bonded to the second conductor plate 13 by bonding material 12a.

[0061] The surfaces of the first power semiconductor element 1a and the third power semiconductor element 1b opposite to the surfaces to which the first conductor plate 3 is joined are joined to the third conductor plate 4 by a bonding material 2b. The electrodes on each surface of the first power semiconductor element 1a and the third power semiconductor element 1b are formed by a structure in which the first conductor plate 3 and the third conductor plate 4 are arranged opposite to their respective electrode surfaces.

[0062] Here, in the power module 100 of this embodiment, the cross-section perpendicular to the junction surface of the first conductor plate 3 and the first power semiconductor element 1a, passing through the center of the first power semiconductor element 1a and the center of the second power semiconductor element 11a, i.e. Figure 5 In the cross-section shown, the first power semiconductor element 1a and the third power semiconductor element 1b are arranged at a position where the first length L1 from the end 3b of the first conductor plate 3 near the second conductor plate 13 to the first power semiconductor element 1a is greater than the third length L3 from the end 3c of the first conductor plate 3 away from the second conductor plate 13 to the third power semiconductor element 1b. The third length L3 is greater than the thickness T1 of the first conductor plate 3.

[0063] Furthermore, the second power semiconductor element 11a and the fourth power semiconductor element 11b are disposed at a position where the fourth length L4 from the end 13b of the second conductor plate 13 closest to the first conductor plate 3 to the second power semiconductor element 11a is greater than the sixth length L6 from the end 13c of the second conductor plate 13 furthest from the first conductor plate 3 to the fourth power semiconductor element 11b. The sixth length L6 is greater than the thickness T2 of the second conductor plate 13. Additionally, the thickness T2 of the second conductor plate 13 can be the same as the thickness T1 of the first conductor plate 3, or it can be a different thickness.

[0064] Other components and references Figure 4 The first embodiment described is the same. In the second embodiment, a power module 100 in which two power semiconductor elements are bonded to adjacent conductor plates 3 and 13 respectively using bonding materials 2a and 12a is used as an example. However, it is also possible to provide three or more power semiconductor elements on adjacent conductor plates 3 and 13. In this case, we also focus on power semiconductor elements disposed at both ends of conductor plates 3 and 13, with power semiconductor elements positioned at L1 > L3 and L4 > L6.

[0065] According to this embodiment, even when multiple power semiconductor elements are provided on the conductor plate, the peeling of the first insulating sheet member 5 and the second insulating sheet member 6 can be prevented, and the heat dissipation performance of the power module 100 can be maintained, thus providing a highly reliable power module 100.

[0066] [Third Implementation Method]

[0067] Figure 6 This is a cross-sectional view of the power module 100 according to the third embodiment. Figure 1 The cross-sectional view of the metal casing 40 shown. Figure 3 The top view of the power module 100 shown is the same in this embodiment.

[0068] In this embodiment, such as Figure 6 As shown, in a cross-section passing through the center of the first power semiconductor element 1 and the center of the second power semiconductor element 11, perpendicular to the junction surface of the first conductor plate 3 and the first power semiconductor element 1, the shape of the end 3b of the first conductor plate 3 near the second conductor plate 13 and the shape of the end 13b of the second conductor plate 13 near the first conductor plate 3 are both tapered towards the junction of each conductor plate 3, 13 and the first insulating sheet member 5. In other words, at the junction of the first conductor plate 3 and the first insulating sheet member 5, and at the junction of the second conductor plate 13 and the first insulating sheet member 5, the connection angle α formed by the inclined surface of the end 3b of the first conductor plate 3 and the surface of the first insulating sheet member 5 is an acute angle. Similarly, the connection angle α formed by the inclined surface of the end 13b of the second conductor plate 13 and the first insulating sheet member 5 is an acute angle. The connection angle α is, for example, about 45° or less.

[0069] By making the junction angle α between the first conductor plate 3 or the second conductor plate 13 and the first insulating sheet member 5 an acute angle, the specificity caused by the bonding of different materials can be reduced, and the heat at the ends 3b and 13b can be further reduced. This suppresses the increase in thermal stress in the portion of the first insulating sheet member 5 in contact with the ends 3b and 13b. Therefore, during power cycles where the first power semiconductor element 1 repeatedly heats up, the thermal stress repeatedly generated on the first insulating sheet member 5 near the ends 3b and 13b can be reduced, thereby improving the lifespan of the power module 100 relative to power cycles.

[0070] In this embodiment, an example is described where the end portion 3b of the first conductor plate 3 and the end portion 13b of the second conductor plate 13 are tapered with a junction angle α. However, the end portions 3c of the first conductor plate 3 and the second conductor plate 13 can also be tapered with a junction angle β. In this case, it is preferable that the junction angle α is more acute than the junction angle β. This further reduces the thermal stress of the first insulating sheet member 5 on both the end portion 3b side of the first conductor plate 3 and the end portion 13b side of the second conductor plate 13.

[0071] Furthermore, in this embodiment, an example was described in which the end 3b of the first conductor plate 3 and the end 13b of the second conductor plate 13 are formed into a tapered shape with a joint angle α. However, the ends of the third conductor plate 4 and the fourth conductor plate 14 can also be formed into tapered shapes. For example, when the adjacent ends of the third conductor plate 4 and the fourth conductor plate 14 are tapered, the width between the third conductor plate 4 and the fourth conductor plate 14 can be increased because the thermal stress of the second insulating sheet member 6 can be reduced. In this case, the material of the third conductor plate 4 and the fourth conductor plate 14 can be reduced, thereby reducing costs.

[0072] According to this embodiment, the thermal stress of the first insulating sheet member 5 and the second insulating sheet member 6 can be further reduced, preventing the peeling of the first insulating sheet member 5 and the second insulating sheet member 6, and maintaining the heat dissipation performance of the power module 100. Therefore, a highly reliable power module 100 can be provided.

[0073] In the above embodiments, the heat sinks 7a and 8a of the first heat sink 7 and the second heat sink 8 are set to be nail-shaped fins, but they can also be other shapes, such as straight fins or corrugated fins.

[0074] The following effects can be obtained by implementing the methods described above.

[0075] (1) The power module 100 includes: a first power semiconductor element 1 and a second power semiconductor element 11; a first conductor plate 3 for bonding the first power semiconductor element 1; a second conductor plate 13 for bonding the second power semiconductor element 11 and disposed adjacent to the first conductor plate 3; a first heat dissipation member 7 disposed opposite to the first conductor plate 3 and the second conductor plate 13; and a first insulating sheet member 5 disposed between the first heat dissipation member 7 and the first conductor plate 3. In a cross-section passing through the center of the first power semiconductor element 1 and the center of the second power semiconductor element 11, perpendicular to the bonding surface of the first conductor plate 3 and the first power semiconductor element 1, the first power semiconductor element 1 is disposed at a position where a first length L1 from the end 3b of the first conductor plate 3 near the second conductor plate 13 side to the first power semiconductor element 1 is greater than a second length L2 from the end 3c of the first conductor plate 3 away from the second conductor plate 13 side to the first power semiconductor element 1. The second length L2 is greater than the thickness T1 of the first conductor plate 3. Thus, peeling of the first insulating sheet member 5 can be prevented, maintaining the heat dissipation performance of the power module 100.

[0076] (2) The power module 100 includes: a first power semiconductor element 1 and a second power semiconductor element 11; a first conductor plate 3 for bonding the first power semiconductor element 1; a second conductor plate 13 for bonding the second power semiconductor element 11 and disposed adjacent to the first conductor plate 3; a first heat dissipation member 7 disposed opposite to the first conductor plate 3 and the second conductor plate 13; and a first insulating sheet member 5 disposed between the first heat dissipation member 7 and the first conductor plate 3, wherein in a cross-section passing through the center of the first power semiconductor element 1 and the center of the second power semiconductor element 11, perpendicular to the bonding surface of the first conductor plate 3 and the first power semiconductor element 1, the center of the first power semiconductor element 1 is disposed closer to the second conductor plate 13. The end 3b of the first conductor plate 3 on one side is closer to the end 3c of the first conductor plate 3 on the side away from the second conductor plate 13 (M11 > M12). The length L1 from the end 3c of the first conductor plate on the side away from the second conductor plate 13 to the first power semiconductor element 1 is greater than the thickness T1 of the first conductor plate 3. The center position of the second power semiconductor element 11 is closer to the end 13c of the second conductor plate 13 on the side away from the first conductor plate 3 than the end 13b on the side closer to the first conductor plate 3 (M14 > M15). The length L5 from the end 13c of the second conductor plate 13 on the side away from the first conductor plate 3 to the second power semiconductor element 11 is greater than the thickness T2 of the second conductor plate 13. Therefore, peeling of the first insulating sheet member 5 can be prevented, maintaining the heat dissipation performance of the power module 100.

[0077] This invention is not limited to the embodiments described above. Other embodiments within the scope of the technical concept of this invention are also included within the scope of this invention, provided they do not impair the characteristics of the invention. Additionally, it may be a combination of the embodiments described above.

[0078] Symbol Explanation

[0079] 1…First power semiconductor element; 2a, 2b, 12a, 12b…Bonding material; 3…First conductor plate; 3b, 3c…Ends of the first conductor plate; 4…Third conductor plate; 4b, 4d…Ends of the third conductor plate 4; 5…First insulating sheet component; 6…Second insulating sheet component; 7…First heat dissipation component; 7a, 8a…Heat dissipation fins; 7b, 8b…Peripheral ends; 8…Second heat dissipation component; 9…First sealing resin; 10…Second sealing resin; 11…Second power semiconductor element 13…Second conductor plate, 13b, 13c…Ends of the second conductor plate, 14…Fourth conductor plate, 14c, 14d…Ends of the fourth conductor plate, 20…Frame, 30…Semiconductor module, 40…Metal housing, 100…Power module, 100a…Socket, L1…First length, L2…Second length, L3…Third length, L4…Fourth length, L5…Fifth length, L6…Sixth length, T1…Thickness of the first conductor plate, T2…Thickness of the second conductor plate.

Claims

1. A power module, characterized by have: First power semiconductor device and second power semiconductor device; A first conductor plate is provided for the first power semiconductor element to be bonded; A second conductor plate is provided for the second power semiconductor element to be bonded and is disposed adjacent to the first conductor plate; A first heat dissipation component is configured opposite to the first conductor plate and the second conductor plate; as well as A first insulating sheet component is disposed between the first heat dissipation component and the first conductor plate. In a cross-section passing through the center of the first power semiconductor element and the center of the second power semiconductor element, perpendicular to the interface between the first conductor plate and the first power semiconductor element, the first power semiconductor element is positioned at a location where a first length from the end of the first conductor plate near the second conductor plate to the first power semiconductor element is greater than a second length from the end of the first conductor plate away from the second conductor plate to the first power semiconductor element, wherein the second length is greater than the thickness of the first conductor plate. At least two power semiconductor elements, namely a first power semiconductor element and a third power semiconductor element, are bonded to the first conductor plate. The third power semiconductor element is bonded to a side of the first conductor plate that is further away from the second conductor plate than the first power semiconductor element. At least two power semiconductor elements, namely a second power semiconductor element and a fourth power semiconductor element, are bonded to the second conductor plate. The fourth power semiconductor element is bonded to a side of the second conductor plate that is further away from the first conductor plate than the second power semiconductor element. In a cross section passing through the center of the first power semiconductor element and the center of the second power semiconductor element, perpendicular to the joint surface of the first conductor plate and the first power semiconductor element, the first power semiconductor element and the third power semiconductor element are disposed at a position where the first length is greater than the third length from the end of the first conductor plate away from the second conductor plate to the third power semiconductor element, and the third length is greater than the thickness of the first conductor plate.

2. The power module according to claim 1, characterized in that, In a cross-section passing through the center of the first power semiconductor element and the center of the second power semiconductor element, perpendicular to the joint surface of the second conductor plate and the second power semiconductor element, the second power semiconductor element is disposed at a position where a fourth length from the end of the second conductor plate near the first conductor plate to the second power semiconductor element is greater than a fifth length from the end of the second conductor plate away from the first conductor plate to the second power semiconductor element, wherein the fifth length is greater than the thickness of the second conductor plate.

3. The power module according to claim 1, characterized in that, In a cross-section passing through the center of the first power semiconductor element and the center of the second power semiconductor element, perpendicular to the joint surface of the second conductor plate and the second power semiconductor element, the second power semiconductor element and the fourth power semiconductor element are disposed at a position where a fourth length from the end of the second conductor plate near the first conductor plate to the second power semiconductor element is greater than a sixth length from the end of the second conductor plate away from the first conductor plate to the fourth power semiconductor element, and the sixth length is greater than the thickness of the second conductor plate.

4. The power module according to claim 1, characterized in that, In a cross-section passing through the center of the first power semiconductor element and the center of the second power semiconductor element, perpendicular to the joint surface of the first conductor plate and the first power semiconductor element, the end of the first conductor plate near the second conductor plate is tapered toward the joint point of the first conductor plate and the first insulating sheet member.

5. The power module according to claim 2 or 3, characterized in that, In a cross-section passing through the center of the first power semiconductor element and the center of the second power semiconductor element, perpendicular to the joint surface of the second conductor plate and the second power semiconductor element, the end of the second conductor plate near the first conductor plate is formed in a cone shape toward the joint point of the second conductor plate and the first insulating sheet member.

6. The power module according to any one of claims 1 to 3, characterized in that, A third conductor plate is bonded to the surface of the first power semiconductor element opposite to the surface to which the first conductor plate is bonded, and a fourth conductor plate is bonded to the surface of the second power semiconductor element opposite to the surface to which the second conductor plate is bonded. The power module includes a second heat dissipation member disposed opposite to the third and fourth conductor plates, and a second insulating sheet member disposed between the second heat dissipation member and the third conductor plate.

7. The power module according to claim 6, characterized in that, It has a housing that engages with the first and second heat dissipation components at their periphery, and at least houses the first power semiconductor element, the second power semiconductor element, the first conductor plate, the second conductor plate, the first heat dissipation component, and the first insulating sheet component.

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