Electric circuit unit, power conversion device, and method for manufacturing electric circuit unit

Abstract

The electrical circuit body of the present invention uses a sheet-like component (440) having a resin insulating layer (441) and a metal foil (442). The sheet-like component (440) deforms following the warping and step difference of the second conductor plate (431) and the fourth conductor plate (433), thereby enabling the thickness of the resin insulating layer (441) to be set to a predetermined thickness of, for example, 120 μm, which can ensure insulation. By plastically deforming a metal-based heat-conducting component (450) having a thickness of, for example, 120 μm, between the sheet-like component (440) and the cooling component (340), the thickness of the metal-based heat-conducting component (450) is changed, thereby absorbing the warping and step difference generated by the second conductor plate (431) and the fourth conductor plate (433). As a result, heat dissipation is significantly improved compared to a case where the conductor plate and the cooling component (340) are connected only through an insulating layer.

Description

Technical Field

[0001] The present invention relates to an electric circuit body, a power conversion device and a method for manufacturing the electric circuit body. Background Art

[0002] Power conversion devices using switches that utilize power semiconductor elements have high conversion efficiency and are therefore widely used in consumer applications, vehicles, railways, and substations. Since these power semiconductor elements generate heat when energized, they require high heat dissipation. For example, in automotive applications, high-efficiency devices using water cooling are employed to achieve compactness and weight reduction. Patent Document 1 discloses a power module in which the heat generated by IGBTs and diodes is transferred to a cooler via metal junctions, a ceramic substrate, and a heat sink.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-26370 Summary of the Invention

[0006] Technical problem to be solved by the invention

[0007] The power module described in Patent Document 1 requires an expensive ceramic substrate.

[0008] Technical solutions used to solve technical problems

[0009] The electrical circuit body involved in the present invention includes: a circuit body having a first power semiconductor element, one surface of the first power semiconductor element being sandwiched by a first conductor plate and the other surface being sandwiched by a second conductor plate; a cooling member arranged on both surfaces of the circuit body; a sheet-like member, the sheet-like member being bonded to at least the second conductor plate and having at least a resin insulating layer; and a metallic heat-conducting member being arranged between the sheet-like member and the cooling member so as to be in contact with the sheet-like member and the cooling member.

[0010] In the method for manufacturing an electric circuit body according to the present invention, a first power semiconductor element is sandwiched between one surface by a first conductor plate and the other surface by a second conductor plate, and a second power semiconductor element is sandwiched between one surface by a third conductor plate and the other surface by a fourth conductor plate. A sheet-like member having at least a resin insulating layer is bonded to the second and fourth conductor plates so as to cover at least the second and fourth conductor plates. A metal heat-conducting member having regions of varying thickness is bonded to the sheet-like member along the arrangement direction of the first and second power semiconductor elements, and a cooling member is brought into close contact with the metal heat-conducting member.

[0011] Effects of the Invention

[0012] According to the present invention, heat dissipation can be improved without using a ceramic substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a top view of the electrical circuit.

[0014] Figure 2 It is a cross-sectional view of the electrical circuit along line XX.

[0015] Figure 3 This is a cross-sectional view of the electrical circuit taken along line YY.

[0016] Figure 4 It is a sectional perspective view of the power module at line XX.

[0017] Figure 5 (a)~ Figure 5 (e) is a cross-sectional view illustrating a method of manufacturing the electric circuit unit.

[0018] Figure 6 (f)~ Figure 6 (h) is a cross-sectional view illustrating a method of manufacturing the electric circuit unit.

[0019] Figure 7 (i)~ Figure 7 (j) is a cross-sectional view showing a first modification of the method for manufacturing the electric circuit unit.

[0020] Figure 8 (k)~ Figure 8 (n) is a cross-sectional view showing a second modification of the method for manufacturing the electric circuit unit.

[0021] Figure 9 This is a semi-transmissive top view of the power module.

[0022] Figure 10 is a circuit diagram showing an example of a circuit of a power module.

[0023] Figure 11 This is a circuit diagram of a power conversion device using a power module.

[0024] Figure 12 It is an external perspective view showing an example of a power conversion device.

[0025] Figure 13 It is a perspective view of a power conversion device taken along line XV-XV. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described below with reference to the accompanying drawings. The following description and drawings are examples for illustrating the present invention and are omitted or simplified as appropriate for clarity. The present invention may also be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0027] To facilitate understanding of the present invention, the positions, sizes, shapes, and ranges of various components shown in the drawings may not necessarily represent actual positions, sizes, shapes, and ranges. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, and ranges disclosed in the drawings.

[0028] Figure 1 is a top view of the electric circuit body 400 according to this embodiment. Figure 2 The electrical circuit 400 Figure 1 A cross-sectional view along line XX is shown. Figure 3 The electrical circuit 400 Figure 1 A cross-sectional view along line YY is shown.

[0029] like Figure 1 As shown, the electrical circuit body 400 is composed of three power modules 300 and a cooling member 340. The power module 300 has the function of converting direct current and alternating current using semiconductor elements, and generates heat when energized. Therefore, a structure is adopted in which a refrigerant is circulated in the cooling member 340 for cooling. The refrigerant used is water, antifreeze obtained by mixing ethylene glycol in water, etc. In addition, the cooling member 340 can be configured as pin-shaped fins standing upright on the substrate of the cooling member 340. In addition, the cooling member 340 can be provided with concave and convex on the contact surface with the metal heat-conducting member 450 described later, so that it can mesh with the metal heat-conducting member 450.

[0030] The power module 300 includes a capacitor module 500 connected to a DC circuit (see below). Figure 11 ) and the positive terminal 315B and the negative terminal 319B, and the motor generators 192 and 194 connected to the AC circuit (see later). Figure 11 ) power terminals through which large currents flow, such as the AC-side terminal 320B. Furthermore, these terminals include signal terminals for controlling the power module, such as the lower arm gate signal terminal 325L, the mirror emitter signal terminal 325M, and the Kelvin emitter signal terminal 325K; and the upper arm gate signal terminal 325U, the mirror emitter signal terminal 325M, and the Kelvin emitter signal terminal 325K.

[0031] like Figure 2As shown, the first power semiconductor element forming the upper arm circuit includes a first active element 155 and a first diode 156. The first active element 155 is, for example, an IGBT or a MOSFET. In the case of a MOSFET, the first diode 156 is unnecessary. Semiconductor materials such as Si, SiC, GaN, GaO, and C can be used to form the first active element 155.

[0032] When the body diode of the active element is used, the first diode 156 can be omitted.

[0033] The semiconductor material constituting the second active element 157 described later is also the same.

[0034] The collector side of the first active element 155 and the cathode side of the first diode 156 are bonded to the first conductor plate 430. Solder or sintered metal can be used for this bonding. The material of the first conductor plate 430 is not particularly limited as long as it has high electrical and thermal conductivity, but copper or aluminum are preferred. These materials can be used alone or plated with Ni, Ag, or other materials to enhance bonding with the sintered metal.

[0035] The emitter side of the first active element 155 and the anode side of the first diode 156 are bonded to the second conductor plate 431. That is, the first active element 155 has one surface sandwiched between the first conductor plate 430 and the other surface sandwiched between the second conductor plate 431, thereby forming the circuit body 310.

[0036] Figure 4 yes Figure 1 The cross-sectional perspective view of the power module 300 at line XX shown in FIG. 1 shows a state where the cooling member 340 and the metal heat-conducting member 450 are removed from the electric circuit body 400. Figure 4 As shown, the second conductor plate 431 has a recess on the periphery of the area connected to the first active element 155 and the first diode 156 to ensure the insulation distance. The recess is preferably formed by stamping to reduce costs. If the recess is formed by stamping, the back surface thereof will be deformed accordingly. Therefore, as shown in FIG. Figure 2 As shown, the second conductor plate 431 has a predetermined warp, for example, a warp of 40 μm, on the side in contact with the cooling member 340 .

[0037] like Figure 3 As shown, the second power semiconductor element forming the lower arm circuit includes a second active element 157 and a second diode 158 (see the following description). Figure 9 、 Figure 10 ). In addition, the second diode 158 is arranged at Figure 3The inner side of the second active element 157 shown. The collector side of the second active element 157 and the cathode side of the second diode 158 are bonded to the third conductor plate 432. The emitter side of the second active element 157 and the anode side of the second diode 158 are bonded to the fourth conductor plate 433. The fourth conductor plate 433 has a warp on the side connected to the cooling member 340, similarly to the second conductor plate 431. In addition, the second conductor plate 431 and the fourth conductor plate 433 are independent conductor plates, and therefore have different inclinations when bonded to the power semiconductor element. As a result, the second conductor plate 431 and the fourth conductor plate 433 not only have a warp of a specified amount (for example, 40 μm) on the side connected to the cooling member 340 as a single body, but also have a warp of a specified amount (for example, 40 μm) as a single body. Figure 3 As shown, when observing from the first power semiconductor element (first active element 155) along the arrangement direction of the second power semiconductor element (second active element 157), the second conductor plate 431 and the fourth conductor plate 433 have a step difference on the side connected to the cooling component 340, and the maximum height deviation is, for example, 120μm.

[0038] Generally, when the second conductor plate 431 and the fourth conductor plate 433 are connected to the cooling member 340 only by an insulating layer, if the thickness of the insulating layer is set to 120 μm to ensure insulation, then in order to absorb the 120 μm height variation caused by step difference and warping, the thickness of the insulating layer needs to be increased to 240 μm. Since the thermal conductivity of the insulating layer is lower than that of metal, if the insulating layer is thickened, the thermal resistance increases, and the heat dissipation performance is significantly reduced.

[0039] In contrast, in this embodiment, if Figure 2 As shown, a sheet-like member 440 having a resin insulating layer 441 and a metal foil 442 is used. Sheet-like member 440 deforms in response to the warping and step differences of second and fourth conductor plates 431 and 433, thereby enabling the thickness of resin insulating layer 441 to be set to a predetermined thickness, for example, 120 μm, to ensure insulation. By interposing a metal heat-conducting member 450, for example, with a thickness of 120 μm, between sheet-like member 440 and cooling member 340 and plastically deforming it, the thickness of metal heat-conducting member 450 changes, absorbing the warping and step differences of second and fourth conductor plates 431 and 433. This significantly improves heat dissipation compared to a case where the conductor plates are connected to cooling member 340 solely through an insulating layer. The resin insulating layer 441 of the sheet member 440 is not particularly limited as long as it has adhesion to the second conductor plate 431 and the fourth conductor plate 433, but is preferably an epoxy resin insulating layer in which a powdered inorganic filler is dispersed, because it has a good balance between adhesion and heat dissipation.

[0040] The circuit body 310 is formed by sandwiching one surface of the first active element 155 between the first conductor plates 430 and the other surface between the second conductor plates 431 . In addition, the power module 300 is formed by sandwiching both surfaces of the circuit body 310 between the sheet-like members 440 .

[0041] The sheet-like member 440 can be a single body of the resin insulating layer 441, but it is preferred that a metal foil 442 be provided on the side in contact with the metal heat-conducting member 450. The metal foil 442 is metal-bonded to the metal heat-conducting member 450. By providing the metal foil 442, the following effect is achieved: when the sheet-like member 440 deforms following the warping and step difference of the second conductor plate 431 and the fourth conductor plate 433, the resin insulating layer 441 before curing can be prevented from cracking. The type of metal foil 442 is not particularly limited, but is preferably aluminum or copper. In particular, copper has the effect of forming an alloy layer with the metal heat-conducting member 450 to reduce the contact thermal resistance. The cooling member 340 is preferably aluminum having a high thermal conductivity and being lightweight.

[0042] The cooling member 340 is manufactured by extrusion molding, forging, brazing, or the like.

[0043] The metal heat-conducting member 450 is not particularly limited as long as it is a material with a yield point lower than that of the cooling member 340 at 200°C or less, but is preferably a material with a lower Young's modulus than that of the cooling member 340. When the yield point is unclear, it can be compared with the 0.2% proof point. This is because the metal heat-conducting member 450 is heated and pressurized by the cooling member 340, thereby causing the metal heat-conducting member 450 to be plastically deformed. The metal heat-conducting member 450 after plastic deformation is arranged along the arrangement direction ( Figure 4 The left-right direction of the first active element 155 and the right-left direction of the second active element 157 and the left-right direction of the second active element 157 and the right-left direction of the second diode 158 are provided. Figure 2 ), and has a region whose thickness varies according to the step difference between the second conductor plate 431 and the fourth conductor plate 433.

[0044] The metal heat conducting member 450 can be an aluminum alloy, a tin alloy, a magnesium alloy, an indium alloy, a silver alloy, a gold alloy, or pure metals thereof. Indium is relatively expensive, but has a lower Young's modulus and yield point, making it more preferred. On the other hand, tin alloys have a higher Young's modulus and yield point than indium, but a lower Young's modulus and yield point than aluminum cooling members, making them the most preferred.

[0045] The power module 300 is formed by sandwiching both sides of the circuit body 310 with sheet-like members 440 . However, a metal heat-conducting member 450 is bonded to the sheet-like member 440 , and the cooling member 340 and the metal heat-conducting member 450 are brought into close contact to form the electric circuit body 400 .

[0046] like Figures 2 to 4 As shown, each power semiconductor element and a portion of the first to fourth conductor plates 430 to 433 are covered and protected by the sealing resin 360 by transfer molding.

[0047] The sheet-shaped member 440 may be included in the transfer molding, or may be bonded after the transfer molding. When the sheet-shaped member 440 is included in the transfer molding, the end of the sheet-shaped member 440 is covered with the sealing resin 360, thereby further improving reliability.

[0048] like Figure 2 、 Figure 3 As shown, the periphery of the metal heat-conducting component 450 can be sealed with an adhesive component 460. In this way, the metal heat-conducting component 450 can be kept in close contact with the cooling component 340. In addition, by sealing with the adhesive component 460, a part of the metal heat-conducting component 450 can be prevented from flying around. By providing a step difference at the periphery of the sealing resin 360, the adhesive component 460 can be prevented from invading between the metal heat-conducting components 450. The adhesive component 460 is not particularly limited as long as it is an insulating material with adhesiveness, but it is preferably a material with a thixotropy of 1.5 or more, which is obtained by dividing the viscosity at a shear rate ratio of 1 (1 / s) by the viscosity at a shear rate ratio of 10 (1 / s), so that the outflow from the coating surface is small. Among them, silicone resins and epoxy resins are preferred. In particular, silicone resins are more preferred because they have a low elastic modulus and therefore low thermal stress.

[0049] Figure 5 (a)~(e) Figure 6 (f) to (h) are cross-sectional views showing a method for manufacturing the electric circuit body 400 according to this embodiment. Figure 1 The XX section shown is shown on the right side of each figure. Figure 1 The YY cross section of the power module 1 is shown.

[0050] Figure 5 (a) is a soldering connection step for the first conductor plate 430 and the third conductor plate 432. The collector side of the first active element 155 and the cathode side of the first diode 156 are connected to the first conductor plate 430. Furthermore, the collector side of the second active element 157 and the cathode side of the second diode 158 are connected to the third conductor plate 432. The second diode 158 is positioned behind the second active element 157.

[0051] Figure 5 (b) is a wire bonding step in which the gate electrodes of the first active element 155 and the second active element 157 are connected.

[0052] Figure 5 (c) is the soldering step of connecting the second conductor plate 431 and the fourth conductor plate 433. The emitter side of the first active element 155 and the anode side of the first diode 156 are connected to the second conductor plate 431. The emitter side of the second active element 157 and the anode side of the second diode 158 are connected to the fourth conductor plate 433. This completes the circuit body 310.

[0053] Figure 5 (d) is a step of crimping the sheet-like member 440. The sheet-like member 440 is bonded to each conductor plate so as to sandwich the first conductor plate 430 and the third conductor plate 432, as well as the second conductor plate 431 and the fourth conductor plate 433 from both sides. Although the sheet-like member 440 is provided as a single sheet-like member 440 covering the second conductor plate 431 and the fourth conductor plate 433, a configuration in which separate sheet-like members 440 cover the second conductor plate 431 and the fourth conductor plate 433, respectively, is also possible.

[0054] Figure 5 (e) is the transfer molding step. In a transfer molding apparatus 601 including a spring 602 and a buffer sheet 603, the sheet-like member 440 covering the second conductor plate 431 and the fourth conductor plate 433 is integrally molded during the transfer molding step. Furthermore, during the transfer molding step, the sealing resin 360 is injected while applying pressure to prevent it from wrapping around the surface of the sheet-like member 440.

[0055] Figure 6 (f) is the tie bar cutting step. Tie bars (not shown) are removed from the transfer molding apparatus 601 and cut to form the terminals. This completes the formation of the terminals and completes the power module 300 comprising the sheet-like member 440 composed of the resin insulating layer 441 and the metal foil 442.

[0056] Figure 6 (g) is the process of installing the metal heat-conducting member 450 and applying the adhesive member 460. The metal heat-conducting member 450 is installed on the sheet-like member 440. An alloy layer is formed at the interface between the metal heat-conducting member 450 and the metal foil 442 by heating and pressurizing. The adhesive member 460 is then applied. Forming the alloy layer at the interface with the metal foil 442 reduces the contact thermal resistance with the metal heat-conducting member 450. The metal heat-conducting member 450 is formed with a cross-sectional shape that is thicker in the center and thinner at both ends. The ends of the metal heat-conducting member 450 are in contact with the adhesive member 460.

[0057] Furthermore, while the metal heat-conducting member 450 has been described as a single member covering the second conductor plate 431 and the fourth conductor plate 433, it may also be configured as a member covering each of the second conductor plate 431 and the fourth conductor plate 433. In this case, as described above, it is preferable to use separate sheet-like members 440 to cover the second conductor plate 431 and the fourth conductor plate 433. Specifically, the metal heat-conducting member 450 may be configured so that the portion contacting the sheet-like member 440 bonded to the second conductor plate 431 and the portion contacting the sheet-like member 440 bonded to the fourth conductor plate 433 are separated from each other. Even in this case, the metal heat-conducting member 450 undergoes plastic deformation, thereby absorbing warpage and step differences that may occur in the second conductor plate 431 and the fourth conductor plate 433, thereby improving heat dissipation.

[0058] Figure 6 (h) is the step of attaching the cooling member 340. The cooling member 340 is brought into close contact with the metallic heat-conducting member 450 and the adhesive member 460. Heat and pressure are applied to reduce the contact thermal resistance between the cooling member 340 and the metallic heat-conducting member 450, and the adhesive member 460 is cured. This completes the electrical circuit assembly 400.

[0059] Figure 7 (i)~ Figure 7 (j) is a cross-sectional view showing a modification 1 of the method for manufacturing the electric circuit body 400 of this embodiment. Figure 1 The XX section shown is shown on the right side of each figure. Figure 1 The YY cross section of the power module 1 is shown.

[0060] In the manufacturing method of modification 1, the Figure 6 (f) to the present are the same, so their description is omitted.

[0061] Figure 7 (i) is a step of installing the metal heat conducting member 450. The metal heat conducting member 450 is installed on the sheet-like member 440. In Modification 1, the adhesive member 460 is not used. The cross section of the metal heat conducting member 450 is a rectangular parallelepiped.

[0062] Figure 7 (j) is the step of placing the cooling member 340 in close contact with the metal heat conductive member 450. During this process, heat and pressure are applied to reduce the contact thermal resistance between the cooling member 340 and the metal heat conductive member 450. This completes the electrical circuit assembly 400.

[0063] Figure 8 (k)~ Figure 8 (n) is a cross-sectional view showing a second modification of the method for manufacturing the electric circuit body of the present embodiment. Figure 1 The XX section shown is shown on the right side of each figure. Figure 1 The YY cross section of the power module 1 is shown.

[0064] In the manufacturing method of modification 2, the Figure 6 (f) to the present are the same, so their description is omitted.

[0065] Figure 8 (k) is the step of applying the metal heat-conducting member 450. The melted metal heat-conducting member 450 is applied to the sheet-like member 440. Applying the melted metal heat-conducting member 450 forms the metal foil 442 and the alloy layer, reducing contact thermal resistance. Furthermore, applying the melted metal heat-conducting member 450 reduces costs compared to using a sheet-like material.

[0066] Figure 8 (1) is a planarization step of the metal heat conductive member 450. The applied metal heat conductive member 450 is planarized in a molten state using a heated deformation jig 604.

[0067] Figure 8 (m) shows a cross section of the metal-based thermally conductive member 450 after being flattened.

[0068] Figure 8 (n) is the step of placing the cooling member 340 in close contact with the metal heat-conducting member 450. At this time, heat and pressure are applied to reduce the contact thermal resistance between the cooling member 340 and the metal heat-conducting member 450. This completes the electrical circuit 400.

[0069] Figure 9 FIG. 3 is a semi-transmissive top view of the power module 300 . Figure 1 The figure shows three power modules 300, but Figure 9 An example of one power module 300 is shown. Figure 10 This is a circuit diagram of one power module 300 .

[0070] like Figure 9 、 Figure 10 As shown, the upper arm circuit includes a first active element 155 and a first diode 156. The lower arm circuit includes a second active element 157 and a second diode 158. The first active element 155 and the second active element 157 are, for example, IGBTs.

[0071] like Figure 9 、 Figure 10As shown, the positive side terminal 315B is output from the collector side of the upper arm circuit, and the positive side terminal 315B is connected to the positive side of the battery or capacitor. The upper arm gate signal terminal 325U senses the output from the gate and emitter of the first active element 155 of the upper arm circuit. The negative side terminal 319B is output from the emitter side of the lower arm circuit, and the negative side terminal 319B is connected to the negative side of the battery or capacitor, or GND. The lower arm gate signal terminal 325L senses the output from the gate and emitter of the second active element 157 of the lower arm circuit. The AC side terminal 320B is output from the collector side of the lower arm circuit and connected to the motor. In the case of neutral point grounding, the lower arm circuit is connected to the negative side of the capacitor instead of GND.

[0072] like Figure 9 As shown, terminals such as a Kelvin emitter signal terminal 325K, a lower arm gate signal terminal 325L, a mirror emitter signal terminal 325M, and an upper arm gate signal terminal 325U are provided. Furthermore, a first conductor plate 430 is provided on the collector side of the upper arm circuit, a second conductor plate 431 is provided on the emitter side of the upper arm circuit, a third conductor plate 432 is provided on the collector side of the lower arm circuit, and a fourth conductor plate 433 is provided on the emitter side of the lower arm circuit. These are sealed with a sealing resin 360.

[0073] The power module of this embodiment has a 2-in-1 structure in which two arm circuits, an upper arm circuit and a lower arm circuit, are integrated into one power module. In addition to the 2-in-1 structure, a 3-in-1 structure in which three arm circuits are integrated into one power module, a 4-in-1 structure in which four arm circuits are integrated into one power module, or a 6-in-1 structure in which six arm circuits are integrated into one power module may also be adopted. When these structures are used, the number of output terminals from the power module can be reduced, thereby achieving miniaturization.

[0074] In addition, this embodiment describes a structure in which two arm circuits, an upper arm circuit and a lower arm circuit, are integrated with a power module. However, this embodiment can also be applied to a structure in which an upper arm circuit or a lower arm circuit is integrated with a power module. That is, when a power module having at least one power semiconductor element and sandwiched between conductor plates disposed on both sides of the power semiconductor element is joined to a cooling member, the sheet-like member 440 and the metal-based heat-conducting member 450 described in this embodiment can be used to absorb the warping and step difference of the conductor plate at the joint surface with the cooling member. As a result, compared with existing structures, an electrical circuit body with improved heat dissipation can be formed.

[0075] Figure 11 This is a circuit diagram of a power conversion device 200 using a power module.

[0076] like Figure 11 As shown, the power conversion device 200 includes inverter circuit units 140 and 142 , an inverter circuit unit 43 for auxiliary equipment, and a capacitor module 500 .

[0077] Inverter circuit units 140 and 142 include multiple semiconductor modules 300, which are connected to form a three-phase inverter circuit. When the current capacity is high, semiconductor modules 300 are further connected in parallel. By performing these parallel connections corresponding to each phase of the three-phase inverter circuit, it is possible to cope with the increase in current capacity. Furthermore, by connecting active elements 155 and 157, and diodes 156 and 158, which serve as power semiconductor elements built into semiconductor modules 300, in parallel, it is also possible to cope with the increase in current capacity.

[0078] The inverter circuit unit 140 and the inverter circuit unit 142 have the same basic circuit structure, and their control methods and operations are also basically the same. The outline of the circuit operation of the inverter circuit unit 140 and the like is well known, so a detailed description is omitted here.

[0079] The upper arm circuit includes an upper arm active element 155 and an upper arm diode 156 as switching power semiconductor elements, while the lower arm circuit includes a lower arm active element 157 and a lower arm diode 158 as switching power semiconductor elements. Active elements 155 and 157 perform switching operations in response to drive signals output from one or the other of the two drive circuits comprising drive circuit 174, converting DC power supplied by battery 136 into three-phase AC power to drive motor generators 192 and 194.

[0080] The upper arm active element 155 and the lower arm active element 157 include a collector electrode, an emitter electrode, and a gate electrode. The upper arm diode 156 and the lower arm diode 158 include two electrodes, a cathode electrode and an anode electrode. Figure 3 As shown, the cathode electrodes of diodes 156 and 158 are electrically connected to the collector electrodes of active elements (IGBTs) 155 and 157, respectively, and the anode electrodes of diodes 156 and 158 are electrically connected to the emitter electrodes of active elements 155 and 157, respectively. Consequently, the current flows from the emitter electrodes of upper-arm active element 155 and lower-arm active element 157 toward the collector electrodes in a clockwise direction.

[0081] Alternatively, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) may be used as the active element. In this case, the upper arm diode 156 and the lower arm diode 158 are unnecessary.

[0082] The positive-side terminal 315B and negative-side terminal 319B of each upper and lower arm series circuit are connected to the capacitor-connecting DC terminals 362A and 362B of the capacitor module 500, respectively. AC power is generated at the connection points of the upper and lower arm circuits, and the connection points of the upper and lower arm circuits of each upper and lower arm series circuit are connected to the AC-side terminals 320B of each semiconductor module 300. The AC-side terminals 320B of each semiconductor module 300 of each phase are connected to the AC output terminals of the power conversion device 200, and the generated AC power is supplied to the stator winding of the motor generator 192 or 194.

[0083] Based on input information from a vehicle-side control device or sensor (e.g., current sensor 180), control circuit 172 generates timing signals for controlling the switching timing of upper-arm active element 155 and lower-arm active element 157. Based on the timing signals output from control circuit 172, drive circuit 174 generates drive signals for switching upper-arm active element 155 and lower-arm active element 157.

[0084] In addition, 181, 182 and 188 are connectors.

[0085] The upper and lower arm series circuits include temperature sensors (not shown), and temperature information from the upper and lower arm series circuits is input to control circuit 172. Furthermore, voltage information on the DC positive side of the upper and lower arm series circuits is input to control circuit 172. Based on this information, control circuit 172 performs overtemperature and overvoltage detection. If overtemperature or overvoltage is detected, control circuit 172 stops switching operations of all upper arm active elements 155 and lower arm active elements 157, thereby protecting the upper and lower arm series circuits from overtemperature or overvoltage.

[0086] Figure 12 It shows Figure 11 An external perspective view of an example of a power conversion device shown in FIG. Figure 13 yes Figure 12 A cross-sectional view of the power conversion device taken along line XV-XV is shown.

[0087] like Figure 12 As shown, the power conversion device 200 is composed of a lower housing 11 and an upper housing 10, and has a housing 12 formed in a substantially rectangular parallelepiped shape. The interior of the housing 12 accommodates the electric circuit body 400, the capacitor module 500, etc. The electric circuit body 400 has a cooling flow path, and the cooling water inlet pipe 13 and the cooling water outlet pipe 14 connected to the cooling flow path protrude from one side of the housing 12. Figure 12As shown, the upper side (Z direction) of the lower housing 11 is open, and the upper housing 10 is attached to the lower housing 11, blocking the opening. The upper housing 10 and the lower housing 11 are formed of aluminum alloy or the like and are sealed from the outside and fixed. The upper housing 10 and the lower housing 11 can be integrally formed. The simple rectangular parallelepiped shape of the outer shell 12 facilitates installation on a vehicle, etc., and also facilitates manufacturing.

[0088] like Figure 12 As shown, a connector 17 is mounted on one side surface in the longitudinal direction of the housing 12, and an AC terminal 18 is connected to the connector 17. In addition, a connector 21 is provided on the surface from which the cooling water inlet pipe 13 and the cooling water outlet pipe 14 are led.

[0089] like Figure 13 As shown, the housing 12 houses the electrical circuit 400. The control circuit 172 and the drive circuit 174 are located above the electrical circuit 400, and the capacitor module 500 is housed on the DC terminal side of the electrical circuit 400. Placing the capacitor module at the same height as the electrical circuit 400 allows for a thinner power conversion device 200, improving the flexibility of vehicle installation. The AC-side terminal 320B of the electrical circuit 400 passes through the current sensor 180 and is connected to the connector 188.

[0090] According to this embodiment, even if the second conductor plate 431 and the fourth conductor plate 433 are warped or tilted, the sheet-like component 440 including the resin insulation layer 441 with low thermal conductivity follows the warping and tilting of the second conductor plate 431 and the fourth conductor plate 433 and is bonded with a specified thickness. On the other hand, the metal heat-conducting component 450 with high thermal conductivity is closely attached to the cooling component 340 by changing its thickness, thereby improving heat dissipation.

[0091] According to the embodiment described above, the following effects can be obtained.

[0092] (1) The electric circuit body 400 includes: a circuit body 310 having a first power semiconductor element (first active element 155), one surface of the first power semiconductor element (first active element 155) being sandwiched between first conductor plates 430 and the other surface being sandwiched between second conductor plates 431; a cooling member 340 disposed on both surfaces of the circuit body 310; a sheet member 440 bonded to at least the second conductor plate 431 and having at least a resin insulating layer 441; and a metal heat-conducting member 450 disposed between the sheet member 440 and the cooling member 340 so as to be in contact with the sheet member 440 and the cooling member 340. Thus, heat dissipation can be improved without using a ceramic substrate.

[0093] (2) In the method for manufacturing the electric circuit body 400, one surface of the first power semiconductor element (first active element 155) is sandwiched between the first conductor plate 430 and the other surface is sandwiched between the second conductor plate 431. Furthermore, one surface of the second power semiconductor element (second active element 157) is sandwiched between the third conductor plate 432 and the other surface is sandwiched between the fourth conductor plate 433. A sheet-like member 440 having at least a resin insulating layer 441 is bonded to the second conductor plate 431 and the fourth conductor plate 433 so as to cover at least the second conductor plate 431 and the fourth conductor plate 433. A metal heat-conducting member 450 having regions of different thicknesses is bonded to the sheet-like member 440 along the arrangement direction of the first power semiconductor element (first active element 155) and the second power semiconductor element (second active element 157). The cooling member 340 is brought into close contact with the metal heat-conducting member 450. This improves heat dissipation without using a ceramic substrate.

[0094] The present invention is not limited to the above-described embodiment, and other embodiments that can be considered within the scope of the technical concept of the present invention are also included in the scope of the present invention as long as the characteristics of the present invention are not impaired. In addition, a structure combining the above-described embodiment and multiple modified examples is also possible.

[0095] Description of labels

[0096] 10 Upper shell

[0097] 11 Lower shell

[0098] 13 Cooling water inlet pipe

[0099] 14 Cooling water outflow pipe

[0100] 17, 21, 181, 182, 188 connectors

[0101] 18 Communication Terminal

[0102] 43, 140, 142 Inverter circuit

[0103] 155 1st active element

[0104] 156 1st diode

[0105] 157 Second active element

[0106] 158 Second diode

[0107] 172 Control Circuit

[0108] 174 drive circuit

[0109] 180 Current Sensor

[0110] 192, 194 Electric generator

[0111] 200 Power conversion device

[0112] 300 Power Module

[0113] 310 loop body

[0114] 315B positive terminal

[0115] 319B negative terminal

[0116] 320B AC side terminal

[0117] 325 signal terminal

[0118] 325K Kelvin emitter signal terminal

[0119] 325L lower arm gate signal terminal

[0120] 325M mirror emitter signal terminal

[0121] 325U upper arm gate signal terminal

[0122] 340 Cooling Components

[0123] 360 Sealing Resin

[0124] 400 electrical circuit

[0125] 430 1st conductor plate (upper arm circuit collector side)

[0126] 431 Second conductor plate (emitter side of upper arm circuit)

[0127] 432 Third conductor plate (lower arm circuit collector side)

[0128] 433 4th conductor plate (emitter side of lower arm circuit)

[0129] 440 Sheet-like member

[0130] 441 resin insulation layer

[0131] 442 metal foil

[0132] 450 Metal thermal conductive components

[0133] 460 Bonding components

[0134] 500 capacitor modules

[0135] 601 Transfer Molding Device

[0136] 602 Spring

[0137] 603 Buffer Sheet

[0138] 604 Deformation fixture.

Claims

1. An electrical circuit body, characterized in that: include: a circuit body having a first power semiconductor element, wherein one surface of the first power semiconductor element is sandwiched between first conductive plates and the other surface is sandwiched between second conductive plates; a cooling member disposed on both sides of the circuit body; a sheet-like member bonded to at least the second conductor plate and having at least a resin insulating layer; as well as a metal heat-conducting member provided between the sheet-shaped member and the cooling member so as to be in contact with the sheet-shaped member and the cooling member; The circuit body includes a second power semiconductor element, and a third conductor plate and a fourth conductor plate sandwiching one surface and the other surface of the second power semiconductor element. The sheet-like member is bonded to the second conductor plate and the fourth conductor plate so as to cover at least the second conductor plate and the fourth conductor plate. The metal heat conducting member has regions having different thicknesses along a direction in which the first power semiconductor element and the second power semiconductor element are arranged.

2. An electrical circuit body, characterized in that: include: a circuit body having a first power semiconductor element, wherein one surface of the first power semiconductor element is sandwiched between first conductive plates and the other surface is sandwiched between second conductive plates; a cooling member disposed on both sides of the circuit body; a sheet-like member bonded to at least the second conductor plate and having at least a resin insulating layer; as well as a metal heat-conducting member provided between the sheet-shaped member and the cooling member so as to be in contact with the sheet-shaped member and the cooling member; The circuit body includes a second power semiconductor element, and a third conductor plate and a fourth conductor plate sandwiching one surface and the other surface of the second power semiconductor element. The sheet-like member includes a first sheet-like member bonded to the second conductor plate and a second sheet-like member bonded to the fourth conductor plate. The metal heat-conducting member has a portion in contact with the first sheet-shaped member and a portion in contact with the second sheet-shaped member separated from each other. The metal heat conducting member has regions having different thicknesses along a direction in which the first power semiconductor element and the second power semiconductor element are arranged.

3. The electric circuit unit according to claim 1 or 2, wherein: The yield point of the metal-based heat-conducting member is lower than that of the cooling member.

4. The electric circuit unit according to claim 1 or 2, wherein: The outer periphery of the metal-based heat-conducting member has an adhesive member.

5. The electric circuit unit according to claim 1 or 2, wherein: The sheet-shaped member is composed of the resin insulating layer and a metal foil, and the metal foil is in contact with the metal-based heat conductive member.

6. The electric circuit unit according to claim 5, wherein: The metal foil is metal-bonded to the metal heat-conducting member.

7. A power conversion device, characterized in that: include: The electric circuit unit according to any one of claims 1 to 6; and An inverter circuit unit formed by combining with the electric circuit body, The power conversion device converts direct current into alternating current.

8. A method for manufacturing an electric circuit body, characterized in that: One surface of the first power semiconductor element is sandwiched between the first conductor plate and the other surface is sandwiched between the second conductor plate. One surface of the second power semiconductor element is sandwiched between the third conductor plate and the other surface is sandwiched between the fourth conductor plate. Adhere a sheet-like member having at least a resin insulating layer to the second conductor plate and the fourth conductor plate so as to cover at least the second conductor plate and the fourth conductor plate, A metal heat conductive member having regions with different thicknesses is bonded to the sheet-like member along the arrangement direction of the first power semiconductor element and the second power semiconductor element. The cooling member is brought into close contact with the metal heat conductive member.

9. The method for manufacturing an electric circuit body according to claim 8, wherein: An adhesive member is applied to the outer periphery of the metallic thermally conductive member.

10. The method for manufacturing an electric circuit body according to claim 8, wherein: The sheet-shaped member is composed of the resin insulating layer and a metal foil, and the metal foil is in contact with the metal-based heat conductive member.

11. The method for manufacturing an electric circuit body according to claim 10, wherein: The metal foil is metal-bonded to the metal heat-conducting member.

12. The method for manufacturing an electric circuit body according to claim 8, wherein: The sheet-like members on the second conductor plate side and the fourth conductor plate side are integrally formed by transfer molding.

13. The method for manufacturing an electric circuit body according to claim 10, wherein: The metallic heat-conducting member is melted and bonded to the metal foil, the surface of the metallic heat-conducting member is flattened, and then the cooling member is brought into close contact.

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