Semiconductor modules and power converters

Abstract

A semiconductor module (2) includes a first insulating substrate (6), a plurality of first semiconductor elements (20, 21, 22), and a conductive wire (33). The first insulating substrate includes a circuit pattern (10). The plurality of first semiconductor elements are arranged on the circuit pattern (10). The plurality of first semiconductor elements include a diode (22) for a converter. The circuit pattern (10) includes a main circuit pattern (12) on which the diode for the converter is mounted and a circuit pattern (18) for a signal which is electrically connected to a unit substrate (3). The length (L1) of the conductive wire (33) between the diode for the converter and the circuit pattern (18) for the signal is larger than the length (L2) of the longest side of the plurality of first semiconductor elements.

Description

Technical Field

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

Background Art

[0002] International Publication No. 2019 / 044748 (Patent Document 1) discloses a semiconductor module.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a semiconductor module and a power conversion device capable of reducing unnecessary current flowing into a unit substrate electrically connected to the semiconductor module.

Means for Solving the Problems

[0005] The semiconductor module of the present disclosure includes a first insulating substrate, a plurality of first semiconductor elements, and conductive wires. The first insulating substrate includes an insulating layer including a main surface, and a circuit pattern disposed on the main surface of the insulating layer. The plurality of first semiconductor elements are disposed on the circuit pattern. The plurality of first semiconductor elements include converter diodes. The circuit pattern includes a main circuit pattern on which the converter diodes are mounted, and a signal circuit pattern electrically connected to the unit substrate. The conductive wires are bonded to the converter diodes and the signal circuit pattern. The length of the conductive wires between the converter diodes and the signal circuit pattern is greater than the length of the maximum side of the plurality of first semiconductor elements in a plan view of the main surface of the insulating layer.

[0006] The power conversion device of this disclosure includes a semiconductor module of this disclosure and comprises a main conversion circuit that converts and outputs input power, and a control circuit that outputs a control signal to the main conversion circuit to control the main conversion circuit. [Effects of the Invention]

[0007] According to the semiconductor module and power converter of this disclosure, it is possible to reduce the unwanted current flowing into the unit substrate electrically connected to the semiconductor module. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing a semiconductor device according to Embodiment 1. [Figure 2] This is a schematic plan view of the semiconductor module according to Embodiment 1. [Figure 3] This is a schematic cross-sectional view of the semiconductor module of Embodiment 1 along the cross-sectional line III-III shown in Figure 2. [Figure 4] This is a circuit diagram of the semiconductor module according to Embodiment 1. [Figure 5] This is a block diagram showing the configuration of the power conversion system according to Embodiment 2. [Figure 6] This is a circuit diagram of the power conversion system according to Embodiment 2. [Figure 7] This is a schematic diagram of the main conversion circuit included in the power conversion system of Embodiment 2. [Figure 8] This is a schematic plan view of the second semiconductor module included in the power conversion system of Embodiment 2. [Modes for carrying out the invention]

[0009] Embodiments of the present disclosure will be described below. The same components will be given the same reference numerals, and their descriptions will not be repeated.

[0010] Embodiment 1. Referring to Figure 1, the semiconductor device 1 of Embodiment 1 will be described. The semiconductor device 1 comprises a semiconductor module 2 and a unit substrate 3. The unit substrate 3 is, for example, a printed circuit board. The unit substrate 3 includes, for example, a gate voltage control circuit 3a, an emitter voltage control circuit 3b, and a monitor circuit 3c. The gate voltage control circuit 3a controls the gate voltage applied to the gate electrode of the semiconductor element 20. The emitter voltage control circuit 3b controls the emitter voltage of the semiconductor element 20. The monitor circuit 3c detects the voltage of the semiconductor element 22 (more specifically, the cathode voltage of the semiconductor element 22).

[0011] The semiconductor module 2 of this embodiment will be described with reference to Figures 2 to 4. The semiconductor module 2 is, for example, a DC / DC converter. The semiconductor module 2 comprises a base plate 5, an insulating substrate 6, a plurality of semiconductor elements 20, 21, 22, conductive wires 30, 31, 32, 33, 34, a case 40, a sealing member 41, and an external electrode 45.

[0012] The base plate 5 is formed from, for example, a metal such as Cu, an alloy such as CuMo, or a metal matrix composite material such as AlSiC. The base plate 5 supports the insulating substrate 6. The base plate 5 dissipates the heat generated in the multiple semiconductor elements 20, 21, and 22 to the outside of the semiconductor module 2.

[0013] The insulating substrate 6 is placed on the base plate 5. The insulating substrate 6 includes an insulating layer 7 and a circuit pattern 10.

[0014] The insulating layer 7 may be formed of a ceramic such as aluminum nitride (AlN), aluminum oxide (Al2O3), or silicon nitride (Si3N4). The insulating layer 7 may also be formed of an organic insulating material in which a filler such as silica, alumina, or boron nitride (BN) is dispersed in a binder resin such as epoxy resin or liquid crystal polymer. The insulating layer 7 includes a main surface 7a on the side opposite to the base plate 5. The insulating layer 7 includes an edge 8 and an edge 9 on the side opposite to edge 8.

[0015] The circuit pattern 10 is disposed on the main surface 7a of the insulating layer 7. The circuit pattern 10 is joined to the insulating layer 7 by means such as brazing. The circuit pattern 10 is formed of a metal such as copper. The circuit pattern 10 is, for example, a rolled copper foil. The circuit pattern 10 includes main circuit patterns 11, 12, conductive pads 13, 14, and signal circuit patterns 15, 16, 17, 18.

[0016] The main circuit pattern 11 is disposed near the edge 8 with respect to the main circuit pattern 12. The main circuit pattern 12 is separated from the main circuit pattern 11 and is disposed near the edge 9 with respect to the main circuit pattern 11. An external electrode 45 is connected to the main circuit pattern 12. For example, the external electrode 45 is an emitter main terminal of the upper arm (described later) of the semiconductor module 2 and is also a cathode main terminal of the lower arm (described later) of the semiconductor module 2.

[0017] The conductive pads 13, 14 are disposed between the main circuit pattern 11 and the main circuit pattern 12. Specifically, a recess is provided at the edge of the main circuit pattern 12 facing the main circuit pattern 11. The conductive pads 13, 14 are disposed within the recess. The conductive pads 13, 14 are separated from the main circuit patterns 11, 12. The conductive pads 13, 14 are separated from each other. For example, an anode main terminal (not shown) of the lower arm (described later) of the semiconductor module 2 is connected to the conductive pads 13, 14.

[0018] The signal circuit patterns 15 and 16 are arranged near the edge 8 with respect to the main circuit pattern 11. The signal circuit pattern 15 is electrically connected to the gate electrode of the semiconductor element 20 and the gate voltage control circuit 3a (see FIG. 1) of the unit substrate 3, and functions as a gate control pattern. The signal circuit pattern 16 is separated from the main circuit pattern 11 and the signal circuit pattern 15, and is arranged between the main circuit pattern 11 and the signal circuit pattern 15. The signal circuit pattern 16 is electrically connected to the emitter electrode of the semiconductor element 20 and the emitter voltage control circuit 3b (see FIG. 1) of the unit substrate 3, and functions as an emitter control pattern. The signal circuit patterns 15 and 16 are, for example, strip conductors.

[0019] The signal circuit patterns 17 and 18 are arranged near the edge 9 with respect to the main circuit pattern 12. The signal circuit pattern 18 is electrically connected to the anode electrode of the semiconductor element 22 and the monitor circuit 3c (see FIG. 1) of the unit substrate 3. The signal circuit pattern 18 is separated from the main circuit pattern 12 and the signal circuit pattern 17, and is arranged between the main circuit pattern 12 and the signal circuit pattern 17. The signal circuit pattern 17 may have the same shape as the signal circuit pattern 15. The signal circuit pattern 18 may have the same shape as the signal circuit pattern 16. The signal circuit patterns 17 and 18 are, for example, strip conductors.

[0020] The plurality of semiconductor elements 20, 21, and 22 are arranged on the circuit pattern 10. Specifically, the semiconductor elements 20 and 21 are mounted on the main circuit pattern 11. The semiconductor elements 20 and 21 constitute the upper arm of the semiconductor module 2. The semiconductor element 22 is mounted on the main circuit pattern 12. The semiconductor element 22 constitutes the lower arm of the semiconductor module 2.

[0021] The semiconductor element 20 is a switching element such as an insulated-gate bipolar transistor (IGBT). The semiconductor element 20 includes a gate electrode, an emitter electrode, and a collector electrode. The collector electrode is joined to the main circuit pattern 11 using a conductive bonding material such as solder, such as lead-free solder, or a metal nanoparticle sintered body, such as a silver nanoparticle sintered body.

[0022] The semiconductor element 21 is a freewheeling element, such as a diode. The semiconductor element 21 includes an anode electrode and a cathode electrode. The cathode electrode of the semiconductor element 21 is joined to the main circuit pattern 11 using a conductive bonding material such as solder, such as lead-free solder, or a metal nanoparticle sintered body, such as a silver nanoparticle sintered body. Each of the semiconductor elements 21 is connected in antiparallel to a corresponding semiconductor element 20.

[0023] The semiconductor element 22 is a converter diode. The semiconductor element 22 includes an anode electrode and a cathode electrode. The cathode electrode of the semiconductor element 22 is joined to the main circuit pattern 12 using a conductive bonding material such as solder, such as lead-free solder, or a metal nanoparticle sintered body, such as a silver nanoparticle sintered body.

[0024] The conductive wires 30, 31, 32, 33, and 34 are metal wires, such as Al wire, Au wire, or Cu wire. More current flows through conductive wires 31, 32, 33, and 34 than through conductive wire 30. Therefore, the diameter of each conductive wire 31, 32, 33, and 34 is greater than the diameter of each conductive wire 30.

[0025] The conductive wire 30 is bonded to the signal circuit pattern 15 and the gate electrode of the semiconductor element 20.

[0026] The conductive wire 31 is bonded to the signal circuit pattern 16, the emitter electrode of the semiconductor element 20, the anode electrode of the semiconductor element 21, and the main circuit pattern 12. The conductive wire 31 is continuously wired to the signal circuit pattern 16, the emitter electrode of the semiconductor element 20, the anode electrode of the semiconductor element 21, and the main circuit pattern 12.

[0027] The conductive wire 32 is bonded to the emitter electrode of the semiconductor element 20, the anode electrode of the semiconductor element 21, and the main circuit pattern 12. The conductive wire 32 is continuously wired to the emitter electrode of the semiconductor element 20, the anode electrode of the semiconductor element 21, and the main circuit pattern 12.

[0028] The conductive wire 33 includes conductive wire 33a and conductive wire 33b. Conductive wire 33a is bonded to the conductive pad 13, the anode electrode of the semiconductor element 22, and the signal circuit pattern 18. Conductive wire 33a is continuously wired to the conductive pad 13, the anode electrode of the semiconductor element 22, and the signal circuit pattern 18. Conductive wire 33b is bonded to the conductive pad 14, the anode electrode of the semiconductor element 22, and the signal circuit pattern 18. Conductive wire 33b is continuously wired to the conductive pad 14, the anode electrode of the semiconductor element 22, and the signal circuit pattern 18. The portion of conductive wire 33 between the semiconductor element 22, which is a converter diode, and the signal circuit pattern 18 functions as a monitoring wire.

[0029] The conductive wire 34 includes conductive wire 34a and conductive wire 34b. Conductive wire 34a is bonded to the conductive pad 13 and the anode electrode of the semiconductor element 22. Conductive wire 34b is bonded to the conductive pad 14 and the anode electrode of the semiconductor element 22.

[0030] The length L1 of the conductive wire 33 between the semiconductor element 22, which is a converter diode, and the signal circuit pattern 18 is greater than the length L2 of the longest side of the multiple semiconductor elements 20, 21, and 22 in a plan view of the main surface 7a of the insulating layer 7. Length L1 is the length between the first bonding portion of the conductive wire 33 that is bonded to the semiconductor element 22 and the second bonding portion of the conductive wire 33 that is bonded to the signal circuit pattern 18. In this embodiment, in a plan view of the main surface 7a of the insulating layer 7, semiconductor element 20 has the longest side among the semiconductor elements 20, 21, and 22. Therefore, length L2 is the length of the longest side of semiconductor element 20 in a plan view of the main surface 7a of the insulating layer 7. The length L1 of the conductive wire 33 is 25 mm or more.

[0031] Referring to Figure 3, the case 40 is formed of an insulating resin such as polyphenyl sulfide resin (PPS), polybutylene terephthalate resin (PBT), or polyethylene terephthalate resin (PET). The case 40 is fixed to the base plate 5 using an adhesive (not shown) or the like. The base plate 5 and the case 40 house an insulating substrate 6, a plurality of semiconductor elements 20, 21, 22, conductive wires 30, 31, 32, 33, 34, and a sealing member 41.

[0032] The sealing member 41 seals a plurality of semiconductor elements 20, 21, and 22. The sealing member 41 may further seal conductive wires 30, 31, 32, 33, and 34. The sealing member 41 is formed of an insulating resin such as epoxy resin or silicone gel. A filler may be dispersed in the insulating resin of the sealing member 41.

[0033] The external electrode 45 is formed of a metal such as copper. The external electrode 45 includes an end 45a and an end 45b opposite to end 45a. End 45a of the external electrode 45 is joined to the main circuit pattern 12. b The external electrode 45 is located outside the case 40. The external electrode 45 penetrates the case 40. The external electrode 45 includes a horizontally extending portion 45c that extends along the main surface 7a of the insulating layer 7.

[0034] In the semiconductor module 2, the maximum height h of the conductive wire 33 from the main circuit pattern 12 is 3 mm or less. Therefore, the horizontally extended portion 45c of the external electrode 45 can be brought closer to the main circuit pattern 12 while maintaining the insulation distance between the horizontally extended portion 45c of the external electrode 45 and the conductive wire 33. The height of the semiconductor module 2 may be reduced. The semiconductor module 2 may be miniaturized. In addition, the height of the sealing member 41 may be reduced. The amount of sealing member 41 used may be reduced, and the cost of the semiconductor module 2 may be reduced.

[0035] The operation and function of the semiconductor module 2 of this embodiment will be described. A first DC voltage is input to the main circuit pattern 11 from an external power supply (not shown). By controlling the semiconductor element 20, which is a switching element, using the gate voltage control circuit 3a and the emitter voltage control circuit 3b, a second DC voltage different from the first DC voltage is output from the external electrode 45. The semiconductor element 22, which is a converter diode, is connected to the monitor circuit 3c via conductive wires 33 and signal circuit pattern 18. The monitor circuit 3c detects the voltage of the semiconductor element 22.

[0036] The length L1 of the conductive wire 33 between the semiconductor element 22, which is a converter diode, and the signal circuit pattern 18 is greater than the length L2 of the longest side of the multiple semiconductor elements 20, 21, and 22 in a plan view of the main surface 7a of the insulating layer 7. Therefore, the electrical resistance of the portion of the conductive wire 33 between the semiconductor element 22, which is a converter diode, and the signal circuit pattern 18 increases. Unwanted current flowing into the unit substrate 3 through the conductive wire 33 and the signal circuit pattern 18 is reduced. Heat generation of the unit substrate 3 due to unwanted current is suppressed, and damage to the unit substrate 3 due to heat can be prevented. In addition, the voltage drop in the portion of the conductive wire 33 between the semiconductor element 22 and the signal circuit pattern 18 due to unwanted current is reduced. Therefore, the voltage of the semiconductor element 22 can be detected more accurately using the monitor circuit 3c.

[0037] The effects of the semiconductor module 2 of this embodiment will be explained. The semiconductor module 2 of this embodiment comprises a first insulating substrate (insulating substrate 6), a plurality of first semiconductor elements (semiconductor elements 20, 21, 22), and conductive wires 33. The first insulating substrate includes an insulating layer 7 including a main surface 7a, and a circuit pattern 10 arranged on the main surface 7a of the insulating layer 7. The plurality of first semiconductor elements are arranged on the circuit pattern 10. The plurality of first semiconductor elements include a converter diode (semiconductor element 22). The circuit pattern 10 includes a main circuit pattern 12 on which the converter diode is mounted, and a signal circuit pattern 18 electrically connected to the unit substrate 3. The conductive wires 33 are bonded to the converter diode and the signal circuit pattern 18. The length L1 of the conductive wires 33 between the converter diode and the signal circuit pattern 18 is greater than the length L2 of the longest side of the plurality of first semiconductor elements in a plan view of the main surface 7a of the insulating layer 7.

[0038] Therefore, the electrical resistance of the conductive wire 33 between the converter diode (semiconductor element 22) and the signal circuit pattern 18 increases. Unwanted current flowing into the unit board 3 through the conductive wire 33 and the signal circuit pattern 18 is reduced. Heat generation of the unit board 3 due to unwanted current is suppressed, and damage to the unit board 3 due to heat can be prevented. In addition, the voltage drop in the conductive wire 33 due to unwanted current is reduced. Therefore, the voltage of the semiconductor element 22 can be detected more accurately using the monitor circuit 3c.

[0039] In the semiconductor module 2 of this embodiment, the length L1 of the conductive wire 33 between the converter diode (semiconductor element 22) and the signal circuit pattern 18 is 25 mm or more.

[0040] Therefore, the electrical resistance of the conductive wire 33 between the converter diode (semiconductor element 22) and the signal circuit pattern 18 increases. Unwanted current flowing into the unit board 3 through the conductive wire 33 and the signal circuit pattern 18 is reduced. Heat generation of the unit board 3 due to unwanted current is suppressed, and damage to the unit board 3 due to heat can be prevented. In addition, the voltage drop in the conductive wire 33 due to unwanted current is reduced. Therefore, the voltage of the semiconductor element 22 can be detected more accurately using the monitor circuit 3c.

[0041] In the semiconductor module 2 of this embodiment, the maximum height h of the conductive wire 33 from the main circuit pattern 12 is 3 mm or less.

[0042] Therefore, the height of semiconductor module 2 is reduced. Semiconductor module 2 can be miniaturized.

[0043] In the semiconductor module 2 of this embodiment, the circuit pattern 10 includes a conductive pad 13. The conductive wire 33 is also bonded to the conductive pad 13. The conductive wire 33 is continuously wired to the conductive pad 13, the converter diode (semiconductor element 22), and the signal circuit pattern 18.

[0044] Therefore, the number of bonding cycles of the conductive wire 33 to the converter diode (semiconductor element 22) is reduced. Damage to the converter diode during bonding of the conductive wire 33 to the converter diode may be reduced. In addition, the space required for wiring the conductive wire 33 is reduced, which may allow the semiconductor module 2 to be miniaturized.

[0045] Embodiment 2. This embodiment applies the semiconductor module 2 of Embodiment 1 described above to a power converter. Although this disclosure is not limited to a specific power converter, Embodiment 2 will be described below, in which the semiconductor module 2 of this disclosure is applied to a three-phase inverter.

[0046] The power conversion system shown in Figure 5 consists of a power source 100, a power converter 200, and a load 300. The power source 100 is a DC power source and supplies DC power to the power converter 200. The power source 100 is not particularly limited, but may consist of, for example, a DC grid, a solar cell or a storage battery, or a rectifier circuit or AC / DC converter connected to an AC grid. The power source 100 may also consist of a DC / DC converter that converts DC power output from a DC grid into a predetermined power.

[0047] The power converter 200 is a three-phase inverter connected between the power supply 100 and the load 300. It converts the DC power supplied from the power supply 100 into AC power and supplies the AC power to the load 300. As shown in Figure 5, the power converter 200 includes a main conversion circuit 201 that converts DC power into AC power and outputs it, and a control circuit 203 that outputs a control signal to the main conversion circuit 201 to control the main conversion circuit 201.

[0048] Load 300 is a three-phase motor driven by AC power supplied from power converter 200. Note that Load 300 is not limited to a specific application; it is a motor installed in various electrical devices, such as hybrid vehicles, electric vehicles, railway vehicles, elevators, or air conditioning equipment.

[0049] The details of the power converter 200 will be described below. As shown in Figures 6 and 7, the main conversion circuit 201 includes a semiconductor module 202a, a semiconductor module 202b, and a heat sink 205. Semiconductor module 202a is semiconductor module 2 of Embodiment 1. Semiconductor module 202b is, for example, an inverter that converts the DC voltage output from semiconductor module 202a into an AC voltage.

[0050] Referring to Figures 6 and 8, the semiconductor module 202b includes a base plate 5, an insulating substrate 6, a plurality of semiconductor elements 20, 21, 24, 25, and conductive wires 30, 31, 32, 35, 36, 37.

[0051] The base plate 5 of semiconductor module 202b (see Figure 8) is the same as the base plate 5 of semiconductor module 202a (see Figures 2 and 3). Both semiconductor modules 202a and 202b are mounted on a heat sink 205. Specifically, the base plate 5 of semiconductor module 202b and the base plate 5 of semiconductor module 202a are bonded to the heat sink 205. The insulating substrate 6 of semiconductor module 202b (see Figure 8) is the same as the insulating substrate 6 of semiconductor module 202a (see Figures 2 and 3). The base plate 5 and insulating substrate 6 are used for both semiconductor module 202a and semiconductor module 202b.

[0052] The semiconductor elements 20 and 21 of semiconductor module 202b are the same as those of semiconductor module 202a. The conductive wires 30, 31, and 32 of semiconductor module 202b are the same as those of semiconductor module 202a.

[0053] The semiconductor element 24, like the semiconductor element 20, is a switching element such as an insulated-gate bipolar transistor (IGBT). The semiconductor element 24 includes a gate electrode, an emitter electrode, and a collector electrode. The collector electrode is joined to the main circuit pattern 12 using a conductive bonding material such as solder, such as lead-free solder, or a metal nanoparticle sintered body, such as a silver nanoparticle sintered body.

[0054] The semiconductor element 25, like the semiconductor element 21, is a freewheeling element such as a diode. The semiconductor element 25 includes an anode electrode and a cathode electrode. The cathode electrode of the semiconductor element 25 is joined to the main circuit pattern 12 using a conductive bonding material such as solder, such as lead-free solder, or a metal nanoparticle sintered body, such as a silver nanoparticle sintered body. Each of the semiconductor elements 25 is connected in antiparallel to a corresponding semiconductor element 24.

[0055] Conductive wires 35, 36, and 37, like conductive wires 30, 31, 32, 33, and 34, are metal wires such as Al wire, Au wire, or Cu wire. More current flows through conductive wires 36 and 37 than through conductive wire 35. Therefore, the diameter of each conductive wire 36 and 37 is larger than the diameter of each conductive wire 35.

[0056] The conductive wire 35 is bonded to the signal circuit pattern 17 and the gate electrode of the semiconductor element 24. The signal circuit pattern 17 is electrically connected to the gate electrode of the semiconductor element 24 and the gate voltage control circuit 3a of the unit substrate 3, and functions as a gate control pattern. The gate voltage control circuit 3a controls the gate voltage applied to the gate electrode of the semiconductor element 24.

[0057] The conductive wire 36 includes conductive wire 36a and conductive wire 36b. Conductive wire 36a is bonded to the signal circuit pattern 18, the emitter electrode of semiconductor element 24, the anode electrode of semiconductor element 25, and the conductive pad 13. Conductive wire 36a is continuously wired to the signal circuit pattern 18, the emitter electrode of semiconductor element 24, the anode electrode of semiconductor element 25, and the conductive pad 13. Conductive wire 36b is bonded to the signal circuit pattern 18, the emitter electrode of semiconductor element 24, the anode electrode of semiconductor element 25, and the conductive pad 14. Conductive wire 36b is continuously wired to the signal circuit pattern 18, the emitter electrode of semiconductor element 24, the anode electrode of semiconductor element 25, and the conductive pad 14.

[0058] The signal circuit pattern 18 is electrically connected to the emitter electrode of the semiconductor element 24 and the emitter voltage control circuit 3b of the unit substrate 3, and functions as an emitter control pattern. The emitter voltage control circuit 3b controls the emitter voltage of the semiconductor element 24.

[0059] The conductive wire 37 includes conductive wire 37a and conductive wire 37b. Conductive wire 37a is bonded to the emitter electrode of semiconductor element 24, the anode electrode of semiconductor element 25, and the conductive pad 13. Conductive wire 37a is continuously wired to the emitter electrode of semiconductor element 24, the anode electrode of semiconductor element 25, and the conductive pad 13. Conductive wire 37b is bonded to the emitter electrode of semiconductor element 24, the anode electrode of semiconductor element 25, and the conductive pad 14. Conductive wire 37b is continuously wired to the emitter electrode of semiconductor element 24, the anode electrode of semiconductor element 25, and the conductive pad 14.

[0060] The number of semiconductor elements 20, 21, 24, and 25 included in semiconductor module 202b is different from the number of semiconductor elements 20, 21, and 22 included in semiconductor module 202a. In this embodiment, the number of semiconductor elements 20, 21, 24, and 25 included in semiconductor module 202b is greater than the number of semiconductor elements 20, 21, and 22 included in semiconductor module 202a.

[0061] The semiconductor elements 20 and 24 of the semiconductor module 202b switch the DC voltage supplied from the semiconductor module 202a, thereby converting the DC power supplied from the semiconductor module 202a into AC power and supplying it to the load 300. The main conversion circuit 201 in this embodiment is a two-level three-phase full-bridge circuit. The semiconductor elements 20 and 21 of the semiconductor module 202b constitute the upper arm of the semiconductor module 202b. The semiconductor elements 24 and 25 constitute the lower arm of the semiconductor module 202b. Each upper and lower arm of the semiconductor module 202b constitutes each phase (U phase, V phase, and W phase) of the full-bridge circuit. The output terminals of each upper and lower arm, i.e., the three output terminals of the main conversion circuit 201, are connected to the load 300.

[0062] Furthermore, the main conversion circuit 201 includes a drive circuit (not shown) for driving the switching elements (semiconductor elements 20, 24). The unit board 3 (see Figure 1) includes the drive circuit. The drive circuit generates drive signals to drive the switching elements included in the main conversion circuit 201 and supplies these drive signals to the control electrodes of the switching elements in the main conversion circuit 201. Specifically, according to the control signal from the control circuit 203, it outputs a drive signal to turn on the switching element and a drive signal to turn off the switching element to the control electrode of each switching element.

[0063] The control circuit 203 controls the switching elements (semiconductor elements 20, 24) of the main converter circuit 201 so that power is supplied to the load 300. Specifically, it calculates the time (on time) that each switching element of the main converter circuit 201 should be in the ON state based on the power to be supplied to the load 300. For example, the main converter circuit 201 can be controlled by PWM control, which modulates the on time of the switching elements according to the voltage to be output to the load 300. Then, it outputs a control command (control signal) to the drive circuit of the main converter circuit 201 so that an ON signal is output to the switching element that should be in the ON state at each point in time, and an OFF signal is output to the switching element that should be in the OFF state. The drive circuit outputs an ON signal or an OFF signal as a drive signal to the control electrode of each switching element according to this control signal. The unit board 3 (see Figure 1) includes the control circuit 203.

[0064] In this embodiment, an example of applying the present disclosure to a two-level three-phase inverter has been described, but the present disclosure is not limited to this and can be applied to various power conversion devices. In this embodiment, a two-level power conversion device is used, but it may also be a three-level power conversion device or a multi-level power conversion device. When the power conversion device supplies power to a single-phase load, the present disclosure may be applied to a single-phase inverter. When the power conversion device supplies power to a DC load, etc., the present disclosure may be applied to a DC / DC converter or an AC / DC converter.

[0065] The power converters to which this disclosure applies are not limited to cases where the load is an electric motor, but may be incorporated, for example, into power supply units for electrical discharge machines or laser processing machines, or power supply units for induction cookers or contactless power supply systems. The power converters to which this disclosure applies may further be used as power conditioners for solar power generation systems or energy storage systems, etc.

[0066] The power converter 200 of this embodiment provides the following effects. The power converter 200 of this embodiment has a first semiconductor module (semiconductor module 202a), which is the semiconductor module 2 of Embodiment 1, and includes a main conversion circuit 201 that converts and outputs the input power, and a control circuit 203 that outputs a control signal to the main conversion circuit 201 to control the main conversion circuit 201.

[0067] Therefore, the amount of unwanted current flowing into the unit board 3 through the conductive wire 33 and the signal circuit pattern 18 is reduced. This suppresses heat generation in the unit board 3 caused by unwanted current, preventing the unit board 3 from being damaged by heat. In addition, the monitor circuit 3c can be used to more accurately detect the voltage of the semiconductor element 22.

[0068] In the power converter 200 of this embodiment, the main conversion circuit 201 further includes a second semiconductor module (semiconductor module 202b). The second semiconductor module includes the same second insulating substrate (semiconductor substrate 6) as the first insulating substrate (semiconductor substrate 6) of the first semiconductor module, and a plurality of second semiconductor elements (semiconductor elements 20, 21, 24, 25). The number of plurality of second semiconductor elements is different from the number of plurality of first semiconductor elements (semiconductor elements 20, 21, 22).

[0069] The second insulating substrate (insulating substrate 6) of the second semiconductor module (semiconductor module 202b) is the same as the first insulating substrate (insulating substrate 6) of the first semiconductor module (semiconductor module 202a). By simply changing the number of semiconductor elements mounted on the insulating substrate 6, the function of the second semiconductor module (e.g., inverter) can be made different from the function of the first semiconductor module (e.g., DC / DC converter). The cost of the power conversion device 200 can be reduced.

[0070] Embodiments 1 and 2 disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than the foregoing description and is intended to include all modifications in the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0071] 1 Semiconductor device, 2 Semiconductor module, 3 Unit board, 3a Gate voltage control circuit, 3b Emitter voltage control circuit, 3c Monitor circuit, 5 Base plate, 6 Insulating substrate, 7 Insulating layer, 7a Main surface, 8,9 Edge, 10 Circuit pattern, 11,12 Main circuit pattern, 13,14 Conductive pads, 15,16,17,18 Signal circuit pattern, 20,21,22,24,25 Semiconductor elements, 30,31,32,33,33a,33b,34,34a,34b,35,36,36a,36b,37,37a,37b Conductive wires, 40 Case, 41 Encapsulating member, 45 External electrode, 45a,45b End, 45c Horizontal extension portion, 100 Power supply, 200 Power converter, 201 Main conversion circuit, 202a, 202b semiconductor modules, 203 control circuit, 205 heat sink, 300 load.

Claims

1. A first insulating substrate comprising an insulating layer including a main surface and a circuit pattern disposed on the main surface, A plurality of first semiconductor elements arranged on the circuit pattern, Equipped with conductive wires, The plurality of first semiconductor elements include a converter diode, The circuit pattern includes a main circuit pattern on which the converter diode is mounted, and a signal circuit pattern electrically connected to a monitor circuit that detects the voltage of the converter diode. The conductive wire is bonded to the converter diode and the signal circuit pattern. A semiconductor module in which the length of the conductive wire between the converter diode and the signal circuit pattern is greater than the length of the longest side of the plurality of first semiconductor elements in a plan view of the main surface.

2. The semiconductor module according to claim 1, wherein the length of the conductive wire between the converter diode and the signal circuit pattern is 25 mm or more.

3. The semiconductor module according to claim 1, wherein the maximum height of the conductive wire from the main circuit pattern is 3 mm or less.

4. The circuit pattern includes a conductive pad, The conductive wire is also bonded to the conductive pad. The semiconductor module according to claim 1, wherein the conductive wire is continuously wired to the conductive pad, the converter diode, and the signal circuit pattern.

5. A first semiconductor module which is the semiconductor module described in any one of claims 1 to 4, and a main conversion circuit which converts and outputs the input power, A power conversion device comprising a control circuit that outputs a control signal to the main conversion circuit to control the main conversion circuit.

6. The main conversion circuit further includes a second semiconductor module. The second semiconductor module includes the same second insulating substrate as the first insulating substrate of the first semiconductor module, and a plurality of second semiconductor elements. The power conversion device according to claim 5, wherein the number of the plurality of second semiconductor elements is different from the number of the plurality of first semiconductor elements.

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