Semiconductor device

Abstract

To provide a semiconductor device capable of improving cost and space savings.SOLUTION: A semiconductor device of the present disclosure includes: a first switching element having a high-voltage terminal, a low-voltage terminal, and a control terminal; a second switching element that is connected in parallel with the first switching element and has a high-voltage terminal, a low-voltage terminal, and a control terminal; a drive circuit that drives the first switching element and the second switching element by supplying a control signal based on the potential of a GND terminal to the control terminal of the first switching element and the control terminal of the second switching element; and a resistor connected between the low-voltage terminal of the first switching element and the low-voltage terminal of the second switching element. The GND terminal of the drive circuit is connected between the low-voltage terminal of the second switching element and the resistor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to semiconductor devices. [Background technology]

[0002] Patent Document 1 discloses a technique for lowering the emitter potential by providing a negative power supply to the emitter section of a switching element in order to increase the gate voltage of the switching element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-175221 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since an external power supply is required to maintain the negative power supply, there are problems in that it requires high cost and a large space.

[0005] In order to solve the above-mentioned problems, an object of the present disclosure is to provide a semiconductor device that can achieve cost savings and space savings. [Means for solving the problem]

[0006] An aspect of the present disclosure is preferably a semiconductor device comprising: a first switching element having a high-voltage terminal, a low-voltage terminal, and a control terminal; a second switching element connected in parallel to the first switching element and having a high-voltage terminal, a low-voltage terminal, and a control terminal; a drive circuit that drives the first switching element and the second switching element by supplying control signals based on the potential of the GND terminal to the control terminal of the first switching element and the control terminal of the second switching element; and a resistor connected between the low-voltage terminal of the first switching element and the low-voltage terminal of the second switching element, wherein the GND terminal of the drive circuit is connected between the low-voltage terminal of the second switching element and the resistor. [Effects of the Invention]

[0007] According to an aspect of the present disclosure, the gate voltage of a switching element can be changed without providing a negative power supply, thereby achieving cost and space savings. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a semiconductor device according to a first embodiment of the present disclosure. [Figure 2] FIG. 10 is a diagram illustrating a semiconductor device according to a second embodiment of the present disclosure. [Figure 3] FIG. 10 is a diagram illustrating a semiconductor device according to a third embodiment of the present disclosure. [Figure 4] FIG. 10 is a diagram illustrating a semiconductor device according to a fourth embodiment of the present disclosure. [Figure 5] FIG. 10 is a diagram illustrating a semiconductor device according to a fifth embodiment of the present disclosure. [Figure 6] FIG. 10 is a diagram illustrating a semiconductor device according to a sixth embodiment of the present disclosure. [Figure 7] FIG. 10 is a diagram illustrating a semiconductor device according to a seventh embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiment 1 FIG. 1 is a diagram illustrating a semiconductor device according to a first embodiment of the present disclosure. The semiconductor device 100 includes a first switching element 4. The first switching element 4 is, for example, an IGBT. The first switching element 4 has a high-voltage terminal, a low-voltage terminal, and a control terminal. When the first switching element 4 is an IGBT, the high-voltage terminal is the collector, the low-voltage terminal is the emitter, and the control terminal is the gate. A free-wheeling element 8 is connected between the emitter and collector of the first switching element.

[0010] In this disclosure, the first switching element 4 is an IGBT, but the present invention is not limited to this and may be, for example, a MOSFET. When the first switching element 4 is a MOSFET, the high-voltage terminal is the drain, the low-voltage terminal is the source, and the control terminal is the gate. The same applies to the second switching element 6 and the third switching element 18 described below.

[0011] The first switching element 4 is connected in parallel with the second switching element 6. The second switching element 6 is, for example, an IGBT. The second switching element 6 has a high-voltage terminal, a low-voltage terminal, and a control terminal. If the second switching element 6 is an IGBT, the high-voltage terminal is the collector, the low-voltage terminal is the emitter, and the control terminal is the gate.

[0012] The semiconductor device 100 also includes a drive circuit 2. The drive circuit 2 is a circuit that drives the first switching element 4 and the second switching element 6. The drive circuit 2 drives the first switching element 4 and the second switching element 6 by supplying control signals based on the potential of the GND terminal 12 to the gates of the first switching element 4 and the second switching element 6.

[0013] A resistor 10 is connected between the emitter of the first switching element 4 and the emitter of the second switching element 6. A GND terminal 12 is connected between the second switching element 6 and the resistor 10.

[0014] An operation example of the semiconductor device 100 is shown. When the drive circuit 2 outputs the on-signal voltage Vo of the first switching element 4 and the second switching element 6, the first switching element 4 and the second switching element 6 become on states. Accordingly, a current flows through the resistor 10, and a potential difference occurs across both ends of the resistor 10.

[0015] At this time, the emitter potential of the first switching element 4 becomes lower than the potential of the GND terminal 12. Therefore, when the gate voltage of the first switching element 4 is Vge, Vo < Vge holds.

[0016] In a general switching element, the higher the gate voltage, the smaller the resistance component between the collector and emitter, and thus the consumed loss is reduced. According to this embodiment, since Vge with respect to Vo can be increased, the resistance component between the collector and emitter of the first switching element 4 can be made smaller, and the consumed loss can be reduced.

[0017] Also, in a general switching element, when the current flowing between the collector and emitter reaches a specific current value, it saturates and cannot conduct current. This specific current value becomes larger as the gate voltage is higher. According to this embodiment, since Vge with respect to Vo can be increased, the current that can flow between the collector and emitter can be increased.

[0018] As described above, according to this embodiment, cost reduction and space saving can be achieved by increasing the gate voltage of the switching element without providing a negative power supply.

[0019] Embodiment 2 FIG. 2 is a diagram showing a semiconductor device according to Embodiment 2 of the present disclosure. The semiconductor device 200 is different from the semiconductor device 100 in that the second switching element 6a is built in the first switching element 4a.

[0020] According to this embodiment, cost reduction and space saving can be achieved by increasing the gate voltage of the switching element without providing a negative power supply. Further, according to this embodiment, further space saving can be achieved by incorporating the second switching element into the first switching element.

[0021] Embodiment 3 FIG. 3 is a diagram showing a semiconductor device according to Embodiment 3 of the present disclosure. The semiconductor device 300 is different from the semiconductor device 200 in that a coil 13 is connected instead of the resistor 10.

[0022] An operation example when the semiconductor device 300 is turned on is shown. When the drive circuit 2 outputs the on-signal voltages Vo of the first switching element 4a and the second switching element 6a, the first switching element 4a and the second switching element 6a become on states. Accordingly, a current flows through the coil 13, generating an electromotive force v (v = L·di / dt).

[0023] At this time, the emitter potential of the first switching element 4a becomes lower than the potential of the GND terminal 12. Therefore, for the gate voltage Vge of the first switching element 4a, Vo < Vge holds. Thereby, the turn-on loss generated in the first switching element 4a can be reduced.

[0024] On the other hand, when the semiconductor device 300 is turned off, a reverse electromotive force -v (-v = L·-di / dt) is generated because the current no longer flows through the coil 13. At this time, the on-signal voltage Vo of the first switching element is 0V. Therefore, for the gate voltage Vge of the first switching element 4, Vo > Vge holds. Thereby, the turn-off loss generated in the first switching element 4a can be reduced.

[0025] As described above, according to this embodiment, cost reduction and space saving can be achieved by increasing the gate voltage of the switching element without providing a negative power supply. Further, according to this embodiment, further cost reduction can be achieved by using a coil instead of a resistor.

[0026] Although the manner of connecting the coil 13 is shown here, any element that generates an electromotive force when current flows may be arranged. For example, a wiring connection manner may also be used.

[0027] Embodiment 4 FIG. 4 is a diagram showing a semiconductor device according to Embodiment 4 of the present disclosure. The semiconductor device 400 is different from the semiconductor device 100 in that it includes a drive circuit 2a having a current source 14 instead of the drive circuit 2 and the second switching element 6. In this case 9, the resistor 10 is connected between the emitter of the first switching element 4 and the GND terminal 12a of the drive circuit 2a.

[0028] An operation example of the semiconductor device 400 is shown. When the drive circuit 2a outputs an on-signal voltage Vo of the first switching element 4, the first switching element 4 becomes in an on state. At the same time, the drive circuit 2a uses the current source 14 to flow a current in the direction from the GND terminal 12a toward the emitter of the first switching element 4. When the current flows, a potential difference occurs across the resistor 10.

[0029] At this time, the emitter potential of the first switching element 4 becomes lower than the potential of the GND terminal 12a. Therefore, for the gate voltage Vge of the first switching element 4, Vo < Vge holds. Thereby, the loss generated in the first switching element 4 can be reduced.

[0030] Also, the current source 14 can change the magnitude of the current flowing through the resistor 10. Thereby, the semiconductor device 400 can adjust the lowering width of the emitter potential of the first switching element 4, that is, the increasing width of the gate-emitter voltage of the first switching element.

[0031] Furthermore, the magnitude of the current that the current source 14 flows through the resistor 10 can be changed independently of the magnitude of the current flowing through the first switching element 4. That is, in the semiconductor device 400, even when the current flowing through the first switching element 4 is low, the gate-emitter voltage of the first switching element 4 can be increased.

[0032] As described above, according to this embodiment, cost and space can be reduced by increasing the gate voltage of the switching element without providing a negative power supply. Furthermore, according to this embodiment, the above-mentioned effects can be obtained regardless of the magnitude of the current flowing through the first switching element 4.

[0033] Fifth embodiment 5 is a diagram illustrating a semiconductor device according to a fifth embodiment of the present disclosure. Semiconductor device 500 differs from semiconductor device 400 in that, instead of drive circuit 2a, it includes drive circuit 2b that causes current to flow in the opposite direction to drive circuit 2a.

[0034] An example of the operation of the semiconductor device 500 is shown below. When the drive circuit 2b outputs an on-signal voltage Vo to the first switching element 4, the first switching element 4 is turned on. At the same time, the drive circuit 2b uses the current source 14 to pass a current from the GND terminal 12a to the emitter of the first switching element 4. The current flow generates a potential difference across the resistor 10.

[0035] At this time, the emitter potential of the first switching element 4 becomes higher than the potential of the GND terminal 12a. Therefore, Vo>Vge holds for Vge, which is the gate voltage of the first switching element 4. This reduces the current that the first switching element 4 can pass, thereby preventing the first switching element 4 from being destroyed.

[0036] As described above, according to this embodiment, it is possible to reduce costs and space by lowering the gate voltage of the switching element without providing a negative power supply. Furthermore, according to this embodiment, it is possible to further suppress breakdown of the switching element.

[0037] Sixth embodiment 6 is a diagram illustrating a semiconductor device according to a sixth embodiment of the present disclosure. The semiconductor device 600 differs from the semiconductor device 200 in that it includes a diode 16 connected in parallel to a resistor 10.

[0038] The diode 16 has an anode connected to the emitter of the first switching element 4a. Therefore, in this embodiment, there are two paths for turning on the gate of the first switching element 4a: one via the resistor 10 and one via the diode 16. In other words, the resistance component in each path can be reduced, and the switching-on speed of the first switching element 4a can be increased.

[0039] As described above, according to this embodiment, cost and space can be reduced by increasing the gate voltage of the switching element without providing a negative power supply. Furthermore, according to this embodiment, the switching-on speed can be further increased.

[0040] Embodiment 7 7 is a diagram illustrating a semiconductor device according to a seventh embodiment of the present disclosure. Semiconductor device 700 differs from semiconductor device 200 in that it includes a third switching element 18. Third switching element 18 is connected in parallel with resistor 10, and has an emitter connected to the emitter of first switching element 4a.

[0041] In the semiconductor device 700, when the first switching element 4a and the built-in second switching element 6a are turned off, the third switching element 18 is turned on. Therefore, in this embodiment, there are two paths for turning off the gate of the first switching element 4a: a path via the resistor 10 and a path via the third switching element 18. In other words, since the resistance component in each path can be reduced, the switching-off speed of the first switching element 4a can be increased.

[0042] As described above, according to this embodiment, cost and space can be reduced by increasing the gate voltage of the switching element without providing a negative power supply. Furthermore, according to this embodiment, the switching-off speed can be further increased.

[0043] Embodiment 8 In the semiconductor devices 100 to 700, the switching elements are formed from silicon. The semiconductor device of this embodiment differs from the semiconductor devices 100 to 700 in that the switching elements are formed from a wide bandgap semiconductor. The wide bandgap semiconductor is, for example, a gallium nitride-based material, a gallium oxide-based material, or diamond.

[0044] Wide bandgap semiconductors have higher heat resistance than silicon, so forming a switching element from a wide bandgap semiconductor makes it possible to operate the semiconductor device under higher temperature conditions or to simplify the heat dissipation structure of the entire semiconductor device.

[0045] Furthermore, wide bandgap semiconductors have lower power loss than silicon, so forming a switching element using a wide bandgap semiconductor allows the semiconductor device to operate at higher speeds.

[0046] Furthermore, wide bandgap semiconductors have higher voltage resistance and allowable current density than silicon, so forming a switching element from a wide bandgap semiconductor allows the switching element to be made smaller, thereby achieving further space savings for the semiconductor device.

[0047] In this embodiment, it is desirable that all of the switching elements included in the semiconductor device are formed from wide bandgap semiconductors, but at least one switching element may be formed from a wide bandgap semiconductor. Even in this case, the effects described in this embodiment can be obtained.

[0048] Below, the aspects of the present disclosure will be summarized as appendices.

[0049] (Appendix 1) a first switching element having a high voltage terminal, a low voltage terminal, and a control terminal; a second switching element connected in parallel with the first switching element and having a high voltage terminal, a low voltage terminal, and a control terminal; a drive circuit that drives the first switching element and the second switching element by supplying a control signal based on the potential of a GND terminal to the control terminal of the first switching element and the control terminal of the second switching element; a resistor connected between the low voltage terminal of the first switching element and the low voltage terminal of the second switching element; Equipped with The GND terminal of the drive circuit is connected between the low voltage terminal of the second switching element and the resistor. Semiconductor device. (Appendix 2) 2. The semiconductor device according to claim 1, further comprising a diode connected in parallel with the resistor and having an anode connected to the low-voltage terminal of the first switching element. (Appendix 3) further comprising a third switching element connected in parallel with the resistor; The drive circuit turns on the third switching element when turning off the first switching element and the second switching element. 3. The semiconductor device according to claim 1, wherein the first and second electrodes are electrically connected to the first and second electrodes. (Appendix 4) The second switching element is built into the first switching element. 4. The semiconductor device according to claim 1. (Appendix 5) The resistor is a coil or a wire. 5. The semiconductor device according to claim 1. (Appendix 6) a first switching element having a high voltage terminal, a low voltage terminal, and a control terminal; a drive circuit that drives the first switching element by supplying a control signal based on the potential of a GND terminal to the control terminal of the first switching element; a resistor connected between the low voltage terminal of the first switching element and a GND terminal of the drive circuit; Equipped with The drive circuit is a semiconductor device having a current source that causes a current to flow through the resistor in a direction from the GND terminal to the low-voltage terminal. (Appendix 7) a first switching element having a high voltage terminal, a low voltage terminal, and a control terminal; a drive circuit that drives the first switching element by supplying a control signal based on the potential of a GND terminal to the control terminal of the first switching element; a resistor disposed between the low voltage terminal of the first switching element and a GND terminal of the drive circuit; Equipped with The drive circuit is a semiconductor device having a current source that causes a current to flow through the resistor in a direction from the low voltage terminal to the GND terminal. (Appendix 8) The first switching element is formed of a wide bandgap semiconductor. 9. A semiconductor device according to any one of claims 1 to 8. [Explanation of symbols]

[0050] 2. Drive circuit 2a Drive circuit 2b Drive circuit 4 First switching element 4a First switching element 6 Second switching element 6a Second switching element 10 Resistance 13 Coil 14 Current source 16 Diodes 18 Third switching element 100 Semiconductor device 200 Semiconductor device 300 Semiconductor device 400 Semiconductor Devices 500 Semiconductor devices 600 Semiconductor devices 700 Semiconductor devices

Claims

1. a first switching element having a high voltage terminal, a low voltage terminal, and a control terminal; a second switching element connected in parallel with the first switching element and having a high voltage terminal, a low voltage terminal, and a control terminal; a drive circuit that supplies a control signal based on a potential of a GND terminal to the control terminal of the first switching element and the control terminal of the second switching element to drive the first switching element and the second switching element; a resistor connected between the low voltage terminal of the first switching element and the low voltage terminal of the second switching element; Equipped with The GND terminal of the drive circuit is connected between the low voltage terminal of the second switching element and the resistor. Semiconductor device.

2. The semiconductor device according to claim 1 , further comprising a diode connected in parallel with the resistor and having an anode connected to the low-voltage terminal of the first switching element.

3. further comprising a third switching element connected in parallel with the resistor; The drive circuit turns on the third switching element when turning off the first switching element and the second switching element. The semiconductor device according to claim 1 .

4. The second switching element is built into the first switching element. The semiconductor device according to claim 1 .

5. The resistor is a coil or a wire. The semiconductor device according to claim 1 .

6. a first switching element having a high voltage terminal, a low voltage terminal, and a control terminal; a drive circuit that drives the first switching element by supplying a control signal based on the potential of a GND terminal to the control terminal of the first switching element; a resistor connected between the low voltage terminal of the first switching element and a GND terminal of the drive circuit; Equipped with The drive circuit is a semiconductor device having a current source that causes a current to flow through the resistor in a direction from the GND terminal to the low voltage terminal.

7. a first switching element having a high voltage terminal, a low voltage terminal, and a control terminal; a drive circuit that drives the first switching element by supplying a control signal based on the potential of a GND terminal to the control terminal of the first switching element; a resistor disposed between the low voltage terminal of the first switching element and a GND terminal of the drive circuit; Equipped with The drive circuit is a semiconductor device having a current source that causes a current to flow through the resistor in a direction from the low voltage terminal to the GND terminal.

8. The first switching element is formed of a wide bandgap semiconductor. The semiconductor device according to any one of claims 1 to 3, 6 and 7.

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