Switch Modules and Inverters
The switch module addresses the lack of detection for semiconductor devices on thick plate portions by incorporating a second stack with lower on-resistance and higher thermal conductivity, enabling effective current and temperature monitoring to prevent overheating and overcurrent, thus improving inverter protection and efficiency.
Patent Information
- Application Number
- JP2024220322
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-12-16
- Publication Date
- 2026-01-06
- Estimated Expiration
- 2041-03-03
AI Technical Summary
Existing switch modules do not provide a configuration for detecting the physical quantity of semiconductor devices mounted on thick plate portions, leading to potential overheating and increased on-resistance issues.
A switch module design with a first and second stack, each containing a semiconductor chip and a mounting portion, where the second stack has a lower on-resistance and is equipped with a current detector, and a coating resin covering the signal terminal with exposed current sensor terminals, and the second mounting portion has higher thermal conductivity.
Enables effective detection of current and temperature in the second semiconductor chip, preventing overheating and overcurrent, thereby enhancing protection and efficiency of the inverter.
Smart Images

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Abstract
Description
[Technical Field]
[0001] The disclosure provided herein provides a switch module including a semiconductor chip. and inverter It is related to. [Background technology]
[0002] Patent Document 1 describes a power supply device that includes a plurality of semiconductor devices, a substrate on which the plurality of semiconductor devices are mounted, and a temperature detector that detects the temperature of one of the plurality of semiconductor devices. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-096886 Summary of the Invention [Problem to be solved by the invention]
[0004] The substrate has a thin plate portion with a small thickness and a thick plate portion with a large thickness. One of the plurality of semiconductor devices is mounted on the thin plate portion. The remaining of the plurality of semiconductor devices is mounted on the thick plate portion.
[0005] A temperature detector is provided on the semiconductor device mounted on the thin plate portion. However, there is no disclosure of a configuration for detecting the physical quantity of the semiconductor device mounted on the thick plate portion (second mounting portion).
[0006] Therefore, an object of the present disclosure is to provide a switch module having a configuration in which a physical quantity of a second semiconductor chip mounted on a second mounting portion is detected. and inverter The purpose is to provide [Means for solving the problem]
[0007] A switch module according to one aspect of the present disclosure includes a first semiconductor chip (310) including a first switch (521), and a first stack (330) including a first mounting portion (531) on which the first semiconductor chip is mounted; a second stack (340) including a second semiconductor chip (320) having a second switch (522) and a second mounting portion (532) for mounting the second semiconductor chip, wherein the on-resistance of the second switch is lower than the on-resistance of the first switch; a current detector (545) provided in the second stack of the first stack and the second stack, for detecting a current flowing through the second switch; a signal terminal (549) connected to the first switch and the second switch; and a coating resin (600) that covers the first laminate, the second laminate, and the signal terminal, with a portion of the signal terminal exposed; The signal terminal includes a current sensor terminal (545a) to which a current detector for detecting a current flowing through the second switch is connected, and includes a terminal for detecting a current through the first switch. figure, At least a part of the material forming the second mounting portion contains a material different from the material forming the first mounting portion, The thermal conductivity of the second mounting section is higher than that of the first mounting section. . A switch module according to one aspect of the present disclosure includes: a first stack (330) including a first semiconductor chip (310) having a first switch (521) and a first mounting portion (531) on which the first semiconductor chip is mounted; a second stack (340) including a second semiconductor chip (320) having a second switch (522) and a second mounting portion (532) for mounting the second semiconductor chip, wherein the on-resistance of the second switch is lower than the on-resistance of the first switch; a current detector (545) provided in the second stack of the first stack and the second stack, for detecting a current flowing through the second switch; a signal terminal (549) connected to the first switch and the second switch; and a coating resin (600) that covers the first laminate, the second laminate, and the signal terminal, with a portion of the signal terminal exposed; the signal terminal includes a current sensor terminal (545a) to which a current detector for detecting a current flowing through the second switch is connected, but does not include a terminal for detecting a current through the first switch; a bonding member (700) provided between the first semiconductor chip and the first mounting portion to bond the first semiconductor chip to the first mounting portion, and between the second semiconductor chip and the second mounting portion to bond the second semiconductor chip to the second mounting portion; At least a portion of the bonding member provided between the second semiconductor chip and the second mounting portion contains a different material having a higher thermal conductivity than the bonding member provided between the first semiconductor chip and the first mounting portion. A switch module according to one aspect of the present disclosure includes: a first stack (330) including a first semiconductor chip (310) having a first switch (521) and a first mounting portion (531) on which the first semiconductor chip is mounted; a second stack (340) including a second semiconductor chip (320) having a second switch (522) and a second mounting portion (532) for mounting the second semiconductor chip, wherein the on-resistance of the second switch is lower than the on-resistance of the first switch; a temperature detector (523) provided on the first stack of the first stack and the second stack, for detecting the temperature of the first switch; a current detector (545) provided in the second stack of the first stack and the second stack, for detecting a current flowing through the second switch; a signal terminal (549) connected to the first switch and the second switch; and a coating resin (600) that covers the first laminate, the second laminate, and the signal terminal, with a portion of the signal terminal exposed; The signal terminals include terminals (546, 547) to which a temperature detector for detecting the temperature of the first switch is connected and a current sensor terminal (545a) to which a current detector for detecting the current flowing through the second switch is connected, and include a terminal for detecting the temperature of the second switch and a terminal for detecting the current of the first switch. figure, At least a part of the material forming the second mounting portion contains a material different from the material forming the first mounting portion, The thermal conductivity of the second mounting section is higher than that of the first mounting section. . A switch module according to one aspect of the present disclosure includes: a first stack (330) including a first semiconductor chip (310) having a first switch (521) and a first mounting portion (531) on which the first semiconductor chip is mounted; a second stack (340) including a second semiconductor chip (320) having a second switch (522) and a second mounting portion (532) for mounting the second semiconductor chip, wherein the on-resistance of the second switch is lower than the on-resistance of the first switch; a temperature detector (523) provided on the first stack of the first stack and the second stack, for detecting the temperature of the first switch; a current detector (545) provided in the second stack of the first stack and the second stack, for detecting a current flowing through the second switch; a signal terminal (549) connected to the first switch and the second switch; and a coating resin (600) that covers the first laminate, the second laminate, and the signal terminal, with a portion of the signal terminal exposed; the signal terminals include terminals (546, 547) to which a temperature detector for detecting the temperature of the first switch is connected and a current sensor terminal (545a) to which a current detector for detecting the current flowing through the second switch is connected, but do not include a terminal for detecting the temperature of the second switch or a terminal for detecting the current of the first switch; a bonding member (700) provided between the first semiconductor chip and the first mounting portion to bond the first semiconductor chip to the first mounting portion, and between the second semiconductor chip and the second mounting portion to bond the second semiconductor chip to the second mounting portion; At least a part of the bonding member provided between the second semiconductor chip and the second mounting portion contains a material having a higher thermal conductivity than the bonding member provided between the first semiconductor chip and the first mounting portion. . An inverter according to one aspect of the present disclosure includes: A high-side switch module (517) and a low-side switch module (518) are connected in series between the first power supply bus bar (301) and the second power supply bus bar (302), The high-side switch module includes a first switch module (511), a third switch module (513), and a fifth switch module (515); The low-side switch module includes a second switch module (512), a fourth switch module (514), and a sixth switch module (516); The first switch module and the second switch module are connected to a U-phase bus bar (410), The third switch module and the fourth switch module are connected to a V-phase bus bar (420), The fifth switch module and the sixth switch module are connected to a W-phase bus bar (430), The first switch module, the second switch module, the third switch module, the fourth switch module, the fifth switch module, and the sixth switch module are the switch modules.
[0008] According to this, a configuration is disclosed in which the amount of current is detected as a physical quantity of the second semiconductor chip (320) mounted on the second mounting portion (532).
[0009] The reference numbers in parentheses above merely indicate the corresponding relationship with the configurations described in the embodiments below, and do not in any way limit the technical scope. [Brief explanation of the drawings]
[0010] [Figure 1] FIG. 1 is a circuit diagram showing an in-vehicle system. [Figure 2] FIG. 2 is a top view illustrating the switch module. [Figure 3] 3 is a top view of the switch module in which some components are removed from FIG. 2. FIG. [Figure 4] 4 is a cross-sectional view of the switch module taken along line IV-IV shown in FIG. 2. FIG. [Figure 5] FIG. 10 is a cross-sectional view illustrating a modified example of the switch module. [Figure 6] FIG. 10 is a top view illustrating a modified example of the switch module. [Figure 7] FIG. 10 is a cross-sectional view illustrating a modified example of the switch module. [Figure 8] FIG. 10 is a cross-sectional view illustrating a modified example of the switch module. [Figure 9]FIG. 10 is a top view illustrating a modified example of the switch module. [Figure 10] FIG. 10 is a top view illustrating a modified example of the switch module. [Figure 11] FIG. 10 is a circuit diagram for explaining a modified example of the connection configuration of the switches. [Figure 12] FIG. 10 is a circuit diagram for explaining a modified example of the connection configuration of the switches. [Figure 13] FIG. 10 is a top view illustrating a modified example of the switch module. [Figure 14] FIG. 10 is a cross-sectional view illustrating a modified example of the switch module. [Figure 15] FIG. 10 is a cross-sectional view illustrating a modified example of the switch module. [Figure 16] FIG. 10 is a top view illustrating a modified example of the switch module. DETAILED DESCRIPTION OF THE INVENTION
[0011] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment will be assigned the same reference numerals, and duplicated explanations may be omitted. In each embodiment, when only a part of the configuration is described, the other previously described embodiments may be applied to the other parts of the configuration.
[0012] In addition, it is not only possible to combine parts that are explicitly stated as being possible in each embodiment, but it is also possible to partially combine embodiments, embodiments and variants, and variants even if not explicitly stated, as long as there are no particular problems with the combination.
[0013] Hereinafter, an embodiment will be described with reference to the drawings.
[0014] (First embodiment) First, an in-vehicle system 100 provided with a power conversion device 300 will be described with reference to Fig. 1. This in-vehicle system 100 constitutes a system for an electric vehicle. The in-vehicle system 100 has a battery 200, a power conversion device 300, a motor 400, and a circuit board (not shown). The circuit board is equipped with multiple ECUs and gate drivers (not shown) that control the driving of switches based on control signals output from the multiple ECUs.
[0015] These multiple ECUs exchange signals with multiple other ECUs installed in various locations on the vehicle. These multiple ECUs cooperate with each other via bus wiring to control the electric vehicle. Through the control of these multiple ECUs, the regeneration and power running of the motor 400 are controlled according to the SOC of the battery 200. SOC stands for state of charge. ECU stands for electronic control unit.
[0016] The ECU generates a pulse signal as a control signal. The ECU adjusts the on-duty ratio and frequency of this pulse signal. The on-duty ratio and frequency are determined based on the output of a sensor (not shown), the target torque of the motor 400, the SOC of the battery 200, and the like.
[0017] Battery 200 has multiple secondary batteries. These multiple secondary batteries are connected in series to form a battery stack. The SOC of this battery stack corresponds to the SOC of battery 200. The secondary batteries may be lithium-ion secondary batteries, nickel-metal hydride secondary batteries, organic radical batteries, or the like.
[0018] The power conversion device 300 has an inverter 500. As the inverter 500, the power conversion device 300 performs power conversion between the battery 200 and the motor 400. The power conversion device 300 converts DC power from the battery 200 into AC power. The power conversion device 300 converts AC power generated by power generation (regeneration) of the motor 400 into DC power.
[0019] The motor 400 is connected to an output shaft of an electric vehicle (not shown). The rotational energy of the motor 400 is transmitted to the running wheels of the electric vehicle via the output shaft. Conversely, the rotational energy of the running wheels is transmitted to the motor 400 via the output shaft.
[0020] The motor 400 is powered by AC power supplied from the power converter 300. This provides a propulsive force to the running wheels. The motor 400 also regenerates power using the rotational energy transmitted from the running wheels. The AC power generated by this regeneration is converted into DC power by the power converter 300. This DC power is supplied to the battery 200. The DC power is also supplied to various electrical loads mounted on the electric vehicle.
[0021] <Inverter> The inverter 500 has a capacitor 303 and a plurality of switch modules 510. A first power supply bus bar 301 and a second power supply bus bar 302 are connected to the battery 200. The capacitor 303 and the plurality of switch modules 510 are connected in parallel between the first power supply bus bar 301 and the second power supply bus bar 302. The plurality of switch modules 510 and the motor 400 are connected via an output bus bar 440. The switch modules 510 correspond to electrical devices.
[0022] When the motor 400 is powered, the high-side switches and low-side switches of the multiple switch modules 510 are each PWM-controlled by a control signal from the ECU. This causes the inverter 500 to generate three-phase AC. When the motor 400 generates (regenerates), the ECU, for example, stops outputting the control signal. This causes AC power generated by the power generation of the motor 400 to pass through diodes of the multiple three-phase switch modules 510. As a result, the AC power is converted into DC power.
[0023] <Switch module> Each of the multiple switch modules 510 has a first switch 521 and a second switch 522. In addition to the first switch 521 and the second switch 522, each of the multiple switch modules 510 also has a first diode 521a, a second diode 522a, a temperature-sensitive diode 523, a current sensor 545, and a signal terminal 549. The temperature-sensitive diode 523 corresponds to a temperature detector. The current sensor 545 corresponds to a current detector.
[0024] The signal terminal 549 has a gate terminal 543a, a current sensor terminal 545a, an anode terminal 546, a cathode terminal 547, and a Kelvin emitter terminal 548. The gate terminal 543a and the Kelvin emitter terminal 548 correspond to a common terminal.
[0025] The first switch 521, the second switch 522, the first diode 521a, the second diode 522a, the temperature sensitive diode 523, the current sensor 545, and the signal terminal 549 are covered with a covering resin 600 to form the switch module 510.
[0026] In this embodiment, an example will be described in which an RCIGBT in which a first diode 521a and a second diode 522a are integrated into the first switch 521 and the second switch 522, respectively, is used. Of course, the switches and diodes may be separate structures. Note that the first switch 521 and the second switch 522 are not limited to IGBTs. The first switch 521 and the second switch 522 may also be semiconductor elements such as MOSFETs.
[0027] 1, a cathode electrode of a first diode 521a is connected to a collector electrode 541 of the first switch 521. An anode electrode of the first diode 521a is connected to an emitter electrode 542 of the first switch 521. The first diode 521a is connected in anti-parallel to the first switch 521.
[0028] A gate terminal 543 a is connected to a gate electrode 543 of the first switch 521 .
[0029] A temperature-sensitive diode 523 is also provided in the first switch 521. The temperature-sensitive diode 523 is a temperature detector for measuring the temperature of the first switch 521. An anode terminal 546 is connected to the anode of the temperature-sensitive diode 523. A cathode terminal 547 is connected to the cathode of the temperature-sensitive diode 523.
[0030] A cathode electrode of a second diode 522a is connected to a collector electrode 541 of the second switch 522. An anode electrode of the second diode 522a is connected to an emitter electrode 542 of the second switch 522. The second diode 522a is connected in anti-parallel to the second switch 522.
[0031] A gate terminal 543 a is connected to a gate electrode 543 of the second switch 522 .
[0032] Further, a current sensor 545 is connected to the second switch 522. The current sensor 545 is a current detector for measuring the current flowing through the second switch 522.
[0033] Furthermore, a Kelvin emitter terminal 548 is electrically connected to the emitter electrode 542 of the first switch 521 and the emitter electrode 542 of the second switch 522. The Kelvin emitter terminal 548 is a terminal for extracting the potential of the emitter electrodes 542 of the first switch 521 and the second switch 522.
[0034] 1, a collector electrode 541 of a first switch 521 and a collector electrode 541 of a second switch 522 are connected via a first conductive part 530. An emitter electrode 542 of the first switch 521 and an emitter electrode 542 of the second switch 522 are connected via a second conductive part 560. This connects the first switch 521 and the second switch 522 in parallel. The first switch 521 and the second switch 522 are simultaneously energized.
[0035] In the drawings, elements common to the first switch 521 and the second switch 522 are assigned the same reference numerals to either the first switch 521 or the second switch 522.
[0036] The plurality of switch modules 510 includes a high-side switch module 517 located on the high side and a low-side switch module 518 located on the low side.
[0037] As shown in FIG. 1, a part of the first conductive portion 530 exposed from the coating resin 600 of the high-side switch module 517 is connected to the first power supply bus bar 301 as a first main terminal.
[0038] A part of the second conductive portion 560 exposed from the coating resin 600 of the low-side switch module 518 is connected to the second power supply bus bar 302 as a second main terminal.
[0039] A part of the second conductive section 560 exposed from the coating resin 600 of the high-side switch module 517 is connected to a part of the first conductive section 530 exposed from the coating resin 600 of the low-side switch module 518.
[0040] As a result, the high-side switch module 517 and the low-side switch module 518 are connected in series between the first power supply bus bar 301 and the second power supply bus bar 302.
[0041] Furthermore, an output bus bar 440 is connected to a part of the second conductive portion 560 of the high-side switch module 517 and a part of the first conductive portion 530 of the low-side switch module 518 .
[0042] The high-side switch module 517 includes a first switch module 511 , a third switch module 513 , and a fifth switch module 515 .
[0043] The low-side switch module 518 includes a second switch module 512 , a fourth switch module 514 and a sixth switch module 516 .
[0044] The output bus bar 440 includes a U-phase bus bar 410 connected to the U-phase stator coil, a V-phase bus bar 420 connected to the V-phase stator coil, and a W-phase bus bar 430 connected to the W-phase stator coil.
[0045] A part of the second conductive portion 560 of the first switch module 511 and a part of the first conductive portion 530 of the second switch module 512 are connected to the U-phase stator coil of the motor 400 via the U-phase bus bar 410 .
[0046] A part of the second conductive portion 560 of the third switch module 513 and a part of the first conductive portion 530 of the fourth switch module 514 are connected to the V-phase stator coil of the motor 400 via the V-phase bus bar 420 .
[0047] The second conductive portion 560 of the fifth switch module 515 and a part of the first conductive portion 530 of the sixth switch module 516 are connected to the W-phase stator coil of the motor 400 via the W-phase bus bar 430 .
[0048] <Switch module mechanical configuration> In the following, the three mutually orthogonal directions are referred to as the x-direction, y-direction, and z-direction. Note that the notation of "direction" is omitted in the drawings. The x-direction corresponds to the first direction. The y-direction corresponds to the second direction. Note that in the drawings, the battery 200 is abbreviated as "BATT."
[0049] In addition to the components described above, the switch module 510 has a first semiconductor substrate 311, a second semiconductor substrate 321, a plurality of pads 570, a plurality of wires 580, a first terminal 591, a second terminal 592, and solder 700. The solder 700 corresponds to a joining member.
[0050] FIG. 2 shows a top view of the switch module 510. FIG. 3 shows a top view of the switch module 510 from FIG. 2, omitting the coating resin 600, the second conductive portion 560, the first terminal 591, the second terminal 592, and the solder 700 between the second conductive portion 560 and the terminals. In FIG. 3, the outline of the coating resin 600 is shown by a two-dot chain line. The boundary between the first mounting portion 531 and the second mounting portion 532 is also shown by a dashed line. This also applies to the drawings described below. FIG. 4 shows a cross-sectional view of the switch module 510 taken along line IV-IV shown in FIG. 2.
[0051] <First semiconductor substrate> The first semiconductor substrate 311 is a substrate on which the first switch 521, the first diode 521a, and the temperature sensitive diode 523 are formed. The first semiconductor substrate 311 is made of silicon, a wide bandgap semiconductor having a wider bandgap than silicon, or the like.
[0052] Examples of wide bandgap semiconductors include silicon carbide, gallium nitride, gallium oxide, and diamond. In Figures 2 and 3, the temperature sensitive diode 523 is shown schematically by a broken line.
[0053] 4, the first semiconductor substrate 311 has a flat shape with a small thickness in the z direction. The first semiconductor substrate 311 has a first substrate surface 311a and a second substrate surface 311b aligned in the z direction.
[0054] A collector electrode 541 is provided on the first substrate surface 311a of the first semiconductor substrate 311. The collector electrode 541 is provided on almost the entire surface of the first substrate surface 311a. The collector electrode 541 also serves as the cathode electrode of the first diode 521a.
[0055] An emitter electrode 542 and a gate electrode 543 are provided on the second substrate surface 311b of the first semiconductor substrate 311. The emitter electrode 542 and the gate electrode 543 are provided on part of the second substrate surface 311b. The emitter electrode 542 also serves as the anode electrode of the first diode 521a. The gate electrode 543 has, for example, a trench gate structure. Although not shown, the gate electrode 543 is buried in the first semiconductor substrate 311.
[0056] 2 or 3, in addition to the emitter electrode 542 and gate electrode 543 described above, at least four functional pads 570 are provided on the second substrate surface 311b. The four pads 570 are provided together at the y-direction end of the second substrate surface 311b, aligned with the emitter electrode 542 in the y-direction. The pads 570 are signal electrodes. The pads 570 are electrically isolated from the emitter electrode 542.
[0057] Specifically, the four pads 570 are a pad 570 for the gate electrode 543, a pad 570 for the anode of the temperature sensitive diode 523, a pad 570 for the cathode of the temperature sensitive diode 523, and a pad 570 for the Kelvin emitter.
[0058] A pad 570 for the gate electrode 543 is connected to a gate terminal 543a via a wire 580. A pad 570 for the anode of the temperature sensitive diode 523 is connected to an anode terminal 546 via a wire 580. A pad 570 for the cathode of the temperature sensitive diode 523 is connected to a cathode terminal 547 via a wire 580. A pad 570 for the Kelvin emitter is connected to a Kelvin emitter terminal 548 via a wire 580.
[0059] Hereinafter, the first semiconductor substrate 311 , the collector electrode 541 , the emitter electrode 542 and the gate electrode 543 will be collectively referred to as a first semiconductor chip 310 .
[0060] <Second semiconductor substrate> The second semiconductor substrate 321 is a substrate on which the second switch 522, the second diode 522a, and the current sensor 545 are provided. The second semiconductor substrate 321 is also formed from silicon, a wide bandgap semiconductor having a wider bandgap than silicon, or the like.
[0061] 2 and 3, the current sensor 545 is shown schematically by a broken line.
[0062] 4, the second semiconductor substrate 321 has a flat shape with a small thickness in the z direction. The second semiconductor substrate 321 has a third substrate surface 321a and a fourth substrate surface 321b aligned in the z direction.
[0063] A collector electrode 541 is provided on the third substrate surface 321a of the second semiconductor substrate 321. The collector electrode 541 is provided on almost the entire surface of the third substrate surface 321a. The collector electrode 541 also serves as the cathode electrode of the second diode 522a.
[0064] An emitter electrode 542 and a gate electrode 543 are provided on a fourth substrate surface 321b of the second semiconductor substrate 321. The emitter electrode 542 and the gate electrode 543 are provided on a part of the fourth substrate surface 321b. The emitter electrode 542 also serves as an anode electrode of the second diode 522a. Although not shown, the gate electrode 543 is embedded in the second semiconductor substrate 321.
[0065] Furthermore, in addition to the gate electrode 543 and emitter electrode 542, at least three functional pads 570 are provided on the fourth substrate surface 321b. The three pads 570 are provided together at the end of the fourth substrate surface 321b in the y direction, aligned with the emitter electrode 542 in the y direction.
[0066] Specifically, the three pads 570 are a pad 570 for the gate electrode 543, a pad 570 for the current sensor 545, and a pad 570 for the Kelvin emitter.
[0067] A pad 570 for the gate electrode 543 is connected to a gate terminal 543a via a wire 580. A pad 570 for the current sensor 545 is connected to a current sensor terminal 545a via a wire 580. A pad 570 for the Kelvin emitter is connected to a Kelvin emitter terminal 548 via a wire 580.
[0068] As shown in Figures 2 and 3, the gate terminal 543a is connected to one of the four pads 570 provided on the first semiconductor substrate 311 and one of the three pads 570 provided on the second semiconductor substrate 321 via different wires 580.
[0069] The Kelvin emitter terminal 548 is connected to one of four pads 570 provided on the first semiconductor substrate 311 and one of three pads 570 provided on the second semiconductor substrate 321 via different wires 580.
[0070] When multiple wires 580 are connected to a terminal, the multiple wires 580 do not have to be connected to the terminal separately. The multiple wires 580 may be bundled together at a relay point between the terminal and the pad 570. It is sufficient that the bundled multiple wires 580 and the terminal are electrically connected.
[0071] Hereinafter, the second semiconductor substrate 321 , the collector electrode 541 , the emitter electrode 542 and the gate electrode 543 will be collectively referred to as the second semiconductor chip 320 .
[0072] <First conductive part> The first conductive part 530 is made of a metal material containing copper or the like. As shown in Fig. 4, the first conductive part 530 has a flat shape with a thin thickness in the z direction. The first conductive part 530 has a first conductive mounting surface 530a and a first conductive exposed surface 530b aligned in the z direction. The first conductive exposed surface 530b corresponds to the exposed surface.
[0073] 2 and 3, the first conductive portion 530 has a first mounting portion 531 and a second mounting portion 532 which have different areas along the x and y directions. The area of the first conductive mounting surface 530a of the first mounting portion 531 is smaller than the area of the first conductive mounting surface 530a of the second mounting portion 532. The area of the first conductive exposed surface 530b of the first mounting portion 531 is smaller than the area of the first conductive exposed surface 530b of the second mounting portion 532. The area of any plane along the x and y directions of the first mounting portion 531 is smaller than the area of any plane along the x and y directions of the second mounting portion 532.
[0074] The first mounting portion 531 and the second mounting portion 532 are aligned in the x direction. The first mounting portion 531 and the second mounting portion 532 are integrally connected. The first mounting portion 531 and the second mounting portion 532 are made of the same material.
[0075] 4, solder 700 is provided on first conductive mounting surface 530a of first mounting portion 531. First semiconductor chip 310 is mounted on first mounting portion 531 in a manner such that collector electrode 541 is in contact with solder 700. Furthermore, solder 700 is provided on emitter electrode 542 of first semiconductor chip 310.
[0076] Similarly, solder 700 is provided on first conductive mounting surface 530a of second mounting portion 532. Second semiconductor chip 320 is mounted on second mounting portion 532 in a manner such that collector electrode 541 is in contact with solder 700. Furthermore, solder 700 is provided on emitter electrode 542 of second semiconductor chip 320.
[0077] <Terminal 1> The first terminal 591 is a block body made of a material containing a metal such as copper.
[0078] First terminal 591 is mounted on first semiconductor chip 310 in a manner that makes contact with solder 700 provided on emitter electrode 542 of first semiconductor chip 310. Furthermore, solder 700 is provided on a portion of first terminal 591 on a side that is spaced apart from first semiconductor chip 310 in the z direction.
[0079] <Terminal 2> The second terminal 592 is a block body made of a material containing a metal such as copper.
[0080] Second terminal 592 is mounted on second semiconductor chip 320 in a manner that makes contact with solder 700 provided on emitter electrode 542 of second semiconductor chip 320. Furthermore, solder 700 is provided on a portion of second terminal 592 on the side away from second semiconductor chip 320 in the z direction.
[0081] <Second conductive part> The second conductive part 560 is made of a metal material containing copper or the like. As shown in Fig. 4, the second conductive part 560 has a flat shape with a thin thickness in the z direction. The second conductive part 560 has a second conductive mounting surface 560a and a second conductive exposed surface 560b aligned in the z direction.
[0082] The second conductive portion 560 has a third mounting portion 561 and a fourth mounting portion 562 which have different areas in the x and y directions. The third mounting portion 561 has the same shape as the first mounting portion 531. The fourth mounting portion 562 has the same shape as the second mounting portion 532.
[0083] The area of the second conductive mounting surface 560a of the third mounting portion 561 is smaller than the area of the second conductive mounting surface 560a of the fourth mounting portion 562. The area of the second conductive exposed surface 560b of the third mounting portion 561 is smaller than the area of the second conductive exposed surface 560b of the fourth mounting portion 562.
[0084] The area of second conductive mounting surface 560a of third mounting portion 561 may be equal to the area of second conductive mounting surface 560a of fourth mounting portion 562. The area of second conductive exposed surface 560b of third mounting portion 561 may be equal to the area of second conductive exposed surface 560b of fourth mounting portion 562.
[0085] The third mounting portion 561 and the fourth mounting portion 562 are aligned in the x direction. The third mounting portion 561 and the fourth mounting portion 562 are integrally connected. The third mounting portion 561 and the fourth mounting portion 562 are made of the same material.
[0086] A second conductive portion 560 is mounted on the first terminal 591 and the second terminal 592 in a manner that the second conductive portion 560 is in contact with the solder 700 provided on the first terminal 591 and the solder 700 provided on the second terminal 592, respectively.
[0087] More specifically, the third mounting portion 561 is mounted on the first terminal 591 in a manner that makes contact with the solder 700 provided on the side of the first terminal 591 that is spaced apart from the first semiconductor chip 310 in the z-direction.
[0088] The fourth mounting portion 562 is mounted on the second terminal 592 in a manner that makes contact with the solder 700 provided on the second terminal 592 at a position spaced apart from the second semiconductor chip 320 in the z direction.
[0089] <Coating resin> The coating resin 600 is made of, for example, an epoxy resin. The coating resin 600 is formed by transfer molding. The coating resin 600 coats some of the components described above.
[0090] 4, the coating resin 600 has a substantially rectangular shape. The coating resin 600 has a first main surface 600a and a second main surface 600b aligned in the z direction, and four connecting surfaces connecting the first main surface 600a and the second main surface 600b.
[0091] The first conductive exposed surface 530b of the first mounting portion 531 and the first conductive exposed surface 530b of the second mounting portion 532 are exposed from the first main surface 600a.
[0092] The second conductive exposed surface 560b of the third mounting portion 561 and the second conductive exposed surface 560b of the fourth mounting portion 562 are exposed from the second main surface 600b.
[0093] A portion of the signal terminal 549 is exposed from one of the four connection surfaces. The signal terminal 549 exposed from the connection surface extends toward the substrate. The signal terminal 549 is electrically connected to the gate driver and ECU mounted on the substrate.
[0094] <First semiconductor chip and second semiconductor chip> As explained above, the first switch 521 is formed on the first semiconductor substrate 311. The second switch 522 is formed on the second semiconductor substrate 321. An IGBT is applied to each of the first switch 521 and the second switch 522.
[0095] As shown in FIG. 4, the thickness of the first semiconductor substrate 311 in the z direction is equal to the thickness of the second semiconductor substrate 321 in the z direction.
[0096] 2 to 4, the area of the first substrate surface 311a of the first semiconductor substrate 311 is equal to the area of the third substrate surface 321a of the second semiconductor substrate 321. The area of the second substrate surface 311b of the first semiconductor substrate 311 is equal to the area of the fourth substrate surface 321b of the second semiconductor substrate 321. The area of any plane along the x and y directions of the first semiconductor substrate 311 is equal to the area of any plane along the x and y directions of the second semiconductor substrate 321.
[0097] The number of first switches 521 formed on the first semiconductor substrate 311 is equal to the number of second switches 522 formed on the second semiconductor substrate 321. The number of first switches 521 provided on the first semiconductor chip 310 is equal to the number of second switches 522 provided on the second semiconductor chip 320.
[0098] <Signal terminal layout> As explained above, the area of any plane along the x and y directions of the first mounting portion 531 is smaller than the area of any plane along the x and y directions of the second mounting portion 532.
[0099] 3, an overlapping region 800 where the projected region of the first mounting portion 531 in the y direction and the projected region of the second mounting portion 532 in the x direction overlap is an air gap. A signal terminal 549 is provided in this overlapping region 800.
[0100] As described above, signal terminals 549 include gate terminal 543a and Kelvin emitter terminal 548 that are commonly connected to first semiconductor chip 310 and second semiconductor chip 320. In the drawing, overlapping region 800 is indicated by hatching.
[0101] <Heat dissipation from semiconductor chip to mounting area> As explained above, the thickness in the z direction of the first mounting portion 531 is equal to the thickness in the z direction of the second mounting portion 532. The area of any plane along the x and y directions of the first mounting portion 531 is smaller than the area of any plane along the x and y directions of the second mounting portion 532. In other words, the volume of the first mounting portion 531 is smaller than the volume of the second mounting portion 532.
[0102] As described above, the number of first switches 521 formed on the first semiconductor substrate 311 is equal to the number of second switches 522 formed on the second semiconductor substrate 321 .
[0103] The heat dissipation from second semiconductor chip 320 to second mounting portion 532 is higher than the heat dissipation from first semiconductor chip 310 to first mounting portion 531. Heat is dissipated more slowly from first semiconductor chip 310 than from second semiconductor chip 320.
[0104] In other words, the heat dissipation performance of the second stack 340 in which the second semiconductor chip 320 is mounted on the second mounting portion 532 is higher than the heat dissipation performance of the first stack 330 in which the first semiconductor chip 310 is mounted on the first mounting portion 531. The first stack 330 dissipates heat more slowly than the second stack 340.
[0105] <Action and effect> As explained above, the temperature sensitive diode 523 that measures the temperature of the first switch 521 is provided on the first semiconductor substrate 311. The current sensor 545 that measures the current flowing through the second switch 522 is provided on the second semiconductor substrate 321.
[0106] According to this, a configuration is disclosed in which a current sensor 545 is mounted on the second stack 340 to measure the current flowing through the second switch 522 as a physical quantity of the second semiconductor chip 320 .
[0107] As explained above, the first switch 521 and the second switch 522 are connected in parallel, and the first switch 521 and the second switch 522 are simultaneously energized.
[0108] As described above, the heat dissipation from second semiconductor chip 320 to second mounting portion 532 is higher than the heat dissipation from first semiconductor chip 310 to first mounting portion 531. The temperature of first semiconductor chip 310 is more likely to become higher than the temperature of second semiconductor chip 320.
[0109] Therefore, the temperature of first switch 521 is likely to become higher than the temperature of second switch 522. Accordingly, the on-resistance of first switch 521 is likely to become higher than the on-resistance of second switch 522. The on-resistance of second switch 522 is likely to become lower than the on-resistance of first switch 521. Therefore, current flows more easily through second switch 522 than through first switch 521.
[0110] This makes it possible to estimate the temperature of second switch 522 based on the temperature of first switch 521. It makes it possible to estimate the value of current flowing through first switch 521 based on the value of current flowing through second switch 522. In this way, a configuration that detects the amount of current flowing through second switch 522 rather than the current flowing through first switch 521 is an effective configuration.
[0111] In other words, the temperature of the second semiconductor chip 320 can be estimated based on the temperature of the first semiconductor chip 310. The value of the current flowing through the first semiconductor chip 310 can be estimated based on the value of the current flowing through the second semiconductor chip 320.
[0112] As explained above, the board is equipped with multiple ECUs and a gate driver (not shown) that controls the operation of the switches based on signals from the multiple ECUs. A signal terminal 549 is electrically connected to the gate driver and the ECU. Therefore, the operation of the first switch 521 and the second switch 522 is controlled based on the detection results of the temperature-sensitive diode 523 and the current sensor 545.
[0113] This makes it possible to limit the driving of the first switch 521 and the second switch 522 before the temperature of the first switch 521 and the second switch 522 rises excessively. It makes it possible to limit the driving of the first switch 521 and the second switch 522 before an overcurrent flows through the first switch 521 and the second switch 522. This improves the protection function of the inverter 500.
[0114] As described above, the signal terminal 549 is provided in an overlapping region 800 where the projected region of the first mounting portion 531 in the y direction and the projected region of the second mounting portion 532 in the x direction overlap. This reduces the size of the switch module 510 in the x direction.
[0115] As described above, signal terminals 549 include gate terminal 543a and Kelvin emitter terminal 548 that are commonly connected to first semiconductor chip 310 and second semiconductor chip 320. This prevents an increase in the number of signal terminals 549. It also prevents an increase in the number of components.
[0116] (First Modification) 5, plating 810 containing nickel, which has a lower thermal conductivity than copper, is applied to first conductive mounting surface 530a and the surface including first conductive mounting surface 530a of first mounting portion 531 and second mounting portion 532. The thickness of plating 810 applied to the surface of second mounting portion 532 may be thinner than the thickness of plating 810 applied to the surface of first mounting portion 531.
[0117] (Second Modification) As shown in FIG. 6, the area of any plane along the x and y directions of the first mounting portion 531 may be equal to the area of any plane along the x and y directions of the second mounting portion 532.
[0118] In this case, it is sufficient that at least a portion of the second mounting portion 532 contains a material having a higher thermal conductivity than the material forming the first mounting portion 531. In Fig. 6, the difference in the materials forming the first mounting portion 531 and the second mounting portion 532 is indicated by different hatching.
[0119] (Third Modification) 7, the thickness in the z direction of the second mounting portion 532 may be greater than the thickness in the z direction of the first mounting portion 531. Furthermore, the thickness in the z direction of the fourth mounting portion 562 may be greater than the thickness in the z direction of the third mounting portion 561.
[0120] (Fourth Modification) As shown in FIG. 8, at least a portion of the solder 700 provided between the second semiconductor chip 320 and the second mounting portion 532 may contain a different material having higher thermal conductivity than the solder 700 provided between the first semiconductor chip 310 and the first mounting portion 531.
[0121] In Figure 8, the difference between the solder 700 provided between the first semiconductor chip 310 and the first mounting portion 531 and the solder 700 provided between the second semiconductor chip 320 and the second mounting portion 532 is indicated by different hatching.
[0122] (Fifth Modification) 9 and 10, the first laminate 330 and the second laminate 340 may be coated with different coating resins 600. The electrical connection between the first switch 521 and the second switch 522 is shown in FIG.
[0123] 11 , collector electrode 541 of first switch 521 is electrically and mechanically connected to collector electrode 541 of second switch 522 via first mounting portion 531 and second mounting portion 532. Similarly, emitter electrode 542 of first switch 521 is electrically and mechanically connected to emitter electrode 542 of second switch 522 via third mounting portion 561 and fourth mounting portion 562.
[0124] (Sixth Modification) As shown in Fig. 12, the first switch 521 and the second switch 522 may be connected in series. In that case, the first mounting portion 531 and the second mounting portion 532 are separate bodies as shown in Fig. 13.
[0125] 14, first mounting portion 531 has first joint 531a extending toward fourth mounting portion 562. Fourth mounting portion 562 has second joint 562a extending toward third mounting portion 561 and connected to first joint 531a. Note that first joint 531a and second joint 562a are electrically and mechanically connected via solder 700. This electrically connects first semiconductor chip 310 and second semiconductor chip 320.
[0126] In addition, a collector electrode 541 of the first switch 521 is electrically and mechanically connected to the first power supply bus bar 301 via the second mounting portion 532. An emitter electrode 542 of the second switch 522 is electrically and mechanically connected to the second power supply bus bar 302 via the third mounting portion 561.
[0127] (Seventh Modification) 15, the thickness in the z direction of the first semiconductor chip 310 may be greater than the thickness in the z direction of the second semiconductor chip 320. In this case, when no current is applied to the first semiconductor chip 310 and the second semiconductor chip 320, the on-resistance of the first semiconductor chip 310 is higher than the on-resistance of the second semiconductor chip 320.
[0128] Therefore, when first semiconductor chip 310 and second semiconductor chip 320 are energized simultaneously, the temperature of first semiconductor chip 310 is likely to become higher than the temperature of second semiconductor chip 320 .
[0129] The temperature of the second semiconductor chip 320 can be estimated based on the temperature of the first semiconductor chip 310. The value of the current flowing through the first semiconductor chip 310 can be estimated based on the value of the current flowing through the second semiconductor chip 320.
[0130] (Eighth Modification) As shown in FIG. 16, the area of any plane along each of the x and y directions of the first semiconductor chip 310 may be smaller than the area of any plane along each of the x and y directions of the second semiconductor chip 320.
[0131] In this case, when the first semiconductor chip 310 and the second semiconductor chip 320 are not energized, the on-resistance of the first semiconductor chip 310 is higher than the on-resistance of the second semiconductor chip 320 .
[0132] Therefore, when first semiconductor chip 310 and second semiconductor chip 320 are energized simultaneously, the temperature of first semiconductor chip 310 is likely to become higher than the temperature of second semiconductor chip 320 .
[0133] The temperature of the second semiconductor chip 320 can be estimated based on the temperature of the first semiconductor chip 310. The value of the current flowing through the first semiconductor chip 310 can be estimated based on the value of the current flowing through the second semiconductor chip 320.
[0134] (Other variations) The semiconductor chips included in the switch module 510 are not limited to the first semiconductor chip 310 and the second semiconductor chip 320. The switch module 510 may include another semiconductor chip in addition to the first semiconductor chip 310 and the second semiconductor chip 320. In this case, the temperature sensitive diode 523 may not be provided on the other semiconductor chip. The current sensor 545 may not be provided on the other semiconductor chip.
[0135] As another example, the types of semiconductor elements applied to the first switch 521 and the second switch 522 may be different. [Explanation of symbols]
[0136] 310...first semiconductor chip, 320...second semiconductor chip, 330...first laminate, 340...second laminate, 521...first switch, 522...second switch, 523...temperature sensitive diode, 530b...first conductive exposed surface, 531...first mounting portion, 532...second mounting portion, 543a...gate terminal, 548...Kelvin emitter terminal, 545...current sensor, 549...signal terminal, 700...solder, 800...overlapping region
Claims
1. a first stack (330) including a first semiconductor chip (310) having a first switch (521) and a first mounting portion (531) on which the first semiconductor chip is mounted; a second stack (340) including a second semiconductor chip (320) having a second switch (522) and a second mounting portion (532) for mounting the second semiconductor chip, wherein the on-resistance of the second switch is lower than the on-resistance of the first switch; a current detector (545) provided on the second stack of the first stack and the second stack, for detecting a current flowing through the second switch; a signal terminal (549) connected to the first switch and the second switch; and a coating resin (600) that covers the first laminate, the second laminate, and the signal terminal, with a portion of the signal terminal exposed; the signal terminal includes a current sensor terminal (545a) to which the current detector for detecting a current flowing through the second switch is connected, but does not include a terminal for detecting a current through the first switch; At least a part of the material forming the second mounting portion contains a material different from the material forming the first mounting portion, The second mounting portion has a higher thermal conductivity than the first mounting portion.
2. a bonding member (700) provided between the first semiconductor chip and the first mounting portion to bond the first semiconductor chip to the first mounting portion, and provided between the second semiconductor chip and the second mounting portion to bond the second semiconductor chip to the second mounting portion; 2. The switch module according to claim 1, wherein at least a portion of the joining member provided between the second semiconductor chip and the second mounting portion contains a different material having a higher thermal conductivity than the joining member provided between the first semiconductor chip and the first mounting portion.
3. a first stack (330) including a first semiconductor chip (310) having a first switch (521) and a first mounting portion (531) on which the first semiconductor chip is mounted; a second stack (340) including a second semiconductor chip (320) having a second switch (522) and a second mounting portion (532) for mounting the second semiconductor chip, wherein the on-resistance of the second switch is lower than the on-resistance of the first switch; a current detector (545) provided on the second stack of the first stack and the second stack, for detecting a current flowing through the second switch; a signal terminal (549) connected to the first switch and the second switch; and a coating resin (600) that covers the first laminate, the second laminate, and the signal terminal, with a portion of the signal terminal exposed; the signal terminal includes a current sensor terminal (545a) to which the current detector for detecting a current flowing through the second switch is connected, but does not include a terminal for detecting a current through the first switch; a bonding member (700) provided between the first semiconductor chip and the first mounting portion to bond the first semiconductor chip to the first mounting portion, and provided between the second semiconductor chip and the second mounting portion to bond the second semiconductor chip to the second mounting portion; A switch module in which at least a portion of the joining member provided between the second semiconductor chip and the second mounting portion contains a different material with a higher thermal conductivity than the joining member provided between the first semiconductor chip and the first mounting portion.
4. 4. The switch module according to claim 1, wherein the heat dissipation of the second laminate is higher than the heat dissipation of the first laminate.
5. a first stack (330) including a first semiconductor chip (310) having a first switch (521) and a first mounting portion (531) on which the first semiconductor chip is mounted; a second stack (340) including a second semiconductor chip (320) having a second switch (522) and a second mounting portion (532) for mounting the second semiconductor chip, wherein the on-resistance of the second switch is lower than the on-resistance of the first switch; a temperature detector (523) provided on the first stack of the first stack and the second stack, for detecting the temperature of the first switch; a current detector (545) provided on the second stack of the first stack and the second stack, for detecting a current flowing through the second switch; a signal terminal (549) connected to the first switch and the second switch; and a coating resin (600) that covers the first laminate, the second laminate, and the signal terminal, with a portion of the signal terminal exposed; the signal terminals include terminals (546, 547) to which the temperature detector for detecting the temperature of the first switch is connected and a current sensor terminal (545a) to which the current detector for detecting the current flowing through the second switch is connected, but do not include a terminal for detecting the temperature of the second switch or a terminal for detecting the current of the first switch; At least a part of the material forming the second mounting portion contains a material different from the material forming the first mounting portion, The second mounting portion has a higher thermal conductivity than the first mounting portion.
6. a bonding member (700) provided between the first semiconductor chip and the first mounting portion to bond the first semiconductor chip to the first mounting portion, and provided between the second semiconductor chip and the second mounting portion to bond the second semiconductor chip to the second mounting portion; 6. A switch module as described in claim 5, wherein at least a portion of the joining member provided between the second semiconductor chip and the second mounting portion contains a different material having a higher thermal conductivity than the joining member provided between the first semiconductor chip and the first mounting portion.
7. a first stack (330) including a first semiconductor chip (310) having a first switch (521) and a first mounting portion (531) on which the first semiconductor chip is mounted; a second stack (340) including a second semiconductor chip (320) having a second switch (522) and a second mounting portion (532) for mounting the second semiconductor chip, wherein the on-resistance of the second switch is lower than the on-resistance of the first switch; a temperature detector (523) provided on the first stack of the first stack and the second stack, for detecting the temperature of the first switch; a current detector (545) provided on the second stack of the first stack and the second stack, for detecting a current flowing through the second switch; a signal terminal (549) connected to the first switch and the second switch; and a coating resin (600) that covers the first laminate, the second laminate, and the signal terminal, with a portion of the signal terminal exposed; the signal terminals include terminals (546, 547) to which the temperature detector for detecting the temperature of the first switch is connected and a current sensor terminal (545a) to which the current detector for detecting the current flowing through the second switch is connected, but do not include a terminal for detecting the temperature of the second switch or a terminal for detecting the current of the first switch; a bonding member (700) provided between the first semiconductor chip and the first mounting portion to bond the first semiconductor chip to the first mounting portion, and provided between the second semiconductor chip and the second mounting portion to bond the second semiconductor chip to the second mounting portion; A switch module in which at least a portion of the joining member provided between the second semiconductor chip and the second mounting portion contains a different material with a higher thermal conductivity than the joining member provided between the first semiconductor chip and the first mounting portion.
8. 8. The switch module according to claim 1, wherein the first switch and the second switch are connected in parallel.
9. the first mounting portion and the second mounting portion are made of the same material, 9. The switch module according to claim 1, wherein the volume of the first mounting portion is smaller than the volume of the second mounting portion.
10. Each of the first mounting portion and the second mounting portion has an exposed surface (530b) exposed from the coating resin, the first stack and the second stack are aligned in a first direction along the exposed surface, 10. The switch module of claim 9, wherein a portion of the signal terminal is located in an overlapping area (800) where a projection area in a second direction perpendicular to the first direction along the exposed surface of the first mounting portion overlaps with a projection area in the first direction of the second mounting portion.
11. 11. The switch module according to claim 10, wherein the signal terminals include common terminals (543a, 548) electrically connected to the first switch and the second switch, respectively.
12. 12. The switch module according to claim 1, wherein an area of the first mounting portion and an area of the second mounting portion are different.
13. The signal terminals include a gate terminal (543a) as a common terminal, the gate terminal is connected to a gate electrode of the first switch, 13. The switch module according to claim 1, wherein the gate terminal is connected to a gate electrode of the second switch.
14. 14. The switch module according to claim 1, wherein the first switch and the second switch are simultaneously energized.
15. A high-side switch module (517) and a low-side switch module (518) are connected in series between the first power supply bus bar (301) and the second power supply bus bar (302), The high-side switch module includes a first switch module (511), a third switch module (513), and a fifth switch module (515); The low-side switch modules include a second switch module (512), a fourth switch module (514), and a sixth switch module (516); The first switch module and the second switch module are connected to a U-phase bus bar (410), The third switch module and the fourth switch module are connected to a V-phase bus bar (420), The fifth switch module and the sixth switch module are connected to a W-phase bus bar (430), An inverter, wherein the first switch module, the second switch module, the third switch module, the fourth switch module, the fifth switch module, and the sixth switch module are switch modules according to any one of claims 1 to 14.
Citation Information
Patent Citations
Method for switching a semiconductor module, semiconductor module and half-bridge
EP3012977A1
Power supply device
JP2014096886A
Semiconductor device
JP2016219532A
Semiconductor device and semiconductor device manufacturing method
JP2017028169A
Semiconductor module and power converter
JP2017195259A