Semiconductor device

Abstract

To reduce switching loss by adjusting driving capability based on the temperature of a switching element, and to reduce a circuit mounting scale.SOLUTION: The semiconductor element 1 includes a switching device 1a, a gate drive circuit 1b, a voltage output device 1c, and a drive capability control circuit 1d. The gate drive circuit 1b drives the switching device 1a. The voltage output device 1c detects a temperature when the switching device 1a is driven, and outputs a voltage Vt corresponding to the temperature. The drive capability control circuit 1d changes the gate drive voltage Vg applied to the gate of the switching device 1a based on the voltage Vt to control the drive capability of the switching device 1a.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a semiconductor device. [Background technology]

[0002] BACKGROUND ART In recent years, development has progressed in semiconductor devices called IPMs (Intelligent Power Modules) that incorporate power semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors) and drive circuits for driving the power semiconductor elements.

[0003] As a related technology, for example, a technology has been proposed in which the gate resistance of a semiconductor element increases when the temperature of the semiconductor element rises above a specified temperature, and decreases when the temperature of the semiconductor element falls below the specified temperature (Patent Document 1). Also proposed is a technology in which the resistance value of the gate resistance of a power element chip increases when the temperature detected by a thermistor built into the power element chip is below a certain value, thereby increasing the loss during switching of the power element chip and raising the temperature (Patent Document 2).

[0004] Furthermore, a technology has been proposed in which the switching speed is maintained at a first speed when the temperature of the switching element is below a predetermined temperature, and the switching speed is changed to a second speed faster than the first speed when the temperature of the switching element is higher than the predetermined temperature (Patent Document 3).

[0005] Also, a technology has been proposed for switching the driving capacity of a switching element by changing the amount of constant current of a constant current supply unit that operates the switching element (Patent Document 4).Furthermore, a technology has been proposed for calculating the slope of a line segment based on the characteristics of a chip temperature detection circuit by performing a correction operation on the measurement value output from an A / D converter when measuring temperature using a temperature detection diode (Patent Document 5). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-127435 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-7934 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-96318 [Patent Document 4] Japanese Patent Application Publication No. 2023-175239 [Patent Document 5] Japanese Patent Application Laid-Open No. 2013-57550 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a semiconductor device that adjusts the driving capability based on the temperature of a switching element to reduce switching loss and also to reduce the circuit packaging scale. [Means for solving the problem]

[0008] To solve the above problems, a semiconductor device is provided, which includes a switching element, a gate drive circuit that drives the switching element, a voltage output element that detects the temperature when the switching element is driven and outputs a voltage according to the temperature, and a drive capacity control circuit that changes the gate drive voltage applied to the gate of the switching element based on the detected voltage, thereby controlling the drive capacity of the switching element. [Effects of the Invention]

[0009] According to one aspect, it is possible to reduce switching loss by adjusting the driving capability based on the temperature of the switching element, and also to reduce the circuit packaging scale. [Brief explanation of the drawings]

[0010] [Figure 1] 1A and 1B are diagrams illustrating an example of a semiconductor device. [Figure 2] FIG. 10 is a diagram for explaining the operation of drive capacity control. [Figure 3] FIG. 10 is a diagram showing an example of a waveform when a switching element is turned on. [Figure 4] FIG. 10 is a diagram illustrating an example of the temperature dependence of switching loss. [Figure 5] FIG. 1 is a diagram illustrating an example of a configuration of a semiconductor device according to a reference example. [Figure 6] 1 is a diagram illustrating an example of a first configuration of a semiconductor device according to an embodiment of the present invention. [Figure 7] 10A and 10B are diagrams for explaining the operation of the driving capability control when the IGBT is in a room temperature state. [Figure 8] 10A and 10B are diagrams for explaining the operation of the driving capability control when the IGBT is in a high temperature state. [Figure 9] FIG. 1 is a diagram showing a first mounting example of circuit components on a semiconductor chip. [Figure 10] FIG. 10 is a diagram showing a second mounting example of circuit components on a semiconductor chip. [Figure 11] FIG. 2 is a diagram illustrating an example of a second configuration of the semiconductor device according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same configuration are designated by the same reference numerals, and redundant description may be omitted.

[0012] 1 is a diagram illustrating an example of a semiconductor device. The semiconductor device 1 includes a switching element 1a, a gate drive circuit 1b, a voltage output element 1c, and a drive capability control circuit 1d. The switching element 1a is a voltage-driven switching element and may be an IGBT or a power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor).

[0013] The gate drive circuit 1b drives the switching element 1a. The voltage output element 1c detects the temperature of the switching element 1a when it is driven and outputs a voltage Vt according to the temperature. For example, the voltage output element 1c can generate a thermoelectromotive force according to the temperature and output the voltage Vt. The drive capacity control circuit 1d changes the gate drive voltage Vg applied to the gate of the switching element 1a based on the voltage Vt, thereby controlling the drive capacity of the switching element 1a.

[0014] 2 is a diagram for explaining the operation of the drive capacity control. The drive capacity control circuit 1d includes a gate resistor Rg and a switch sw connected in parallel to the gate resistor Rg and turned on and off in response to a voltage Vt.

[0015] [Step S1] When the switching element 1a is in a first temperature state (room temperature state), the voltage output element 1c does not output a voltage of a predetermined level even when it detects the first temperature of the switching element 1a, and the voltage Vt becomes low level with respect to the switch sw.

[0016] [Step S2] The switch sw is turned off when the voltage Vt is at a low level. [Step S3] Because the drive signal sg1 output from the gate drive circuit 1b flows through the gate resistor Rg, the drive capability control circuit 1d generates a gate drive voltage Vg1 (first gate drive voltage) based on the resistance value of the gate resistor Rg. Then, the drive capability control circuit 1d applies the gate drive voltage Vg1 to the gate of the switching element 1a to drive the switching element 1a with the first drive capability.

[0017] [Step S11] When the switching element 1a is in a second temperature state (high temperature state) higher than the first temperature, the voltage output element 1c detects the second temperature of the switching element 1a, and the predetermined level of voltage Vt becomes high level for the switch sw.

[0018] [Step S12] The switch sw is turned on when the voltage Vt is at a high level. [Step S13] Since the drive signal sg1 output from the gate drive circuit 1b flows through the gate resistor Rg and the switch sw, the drive capability control circuit 1d generates a gate drive voltage Vg2 (second gate drive voltage) based on the combined resistance value of the gate resistor Rg and the on-resistance of the switch sw.

[0019] Then, the drive capacity control circuit 1d applies a gate drive voltage Vg2 to the gate of the switching element 1a, causing the switching element 1a to be driven at a second drive capacity with a switching speed faster than the switching speed at the first drive capacity.

[0020] In this way, in semiconductor device 1, the voltage output element outputs a voltage according to the temperature when the switching element is driven, and the gate drive voltage is changed based on that voltage to control the drive capacity of the switching element. This makes it possible to adjust the drive capacity based on the temperature of the switching element, reduce switching loss, and reduce the circuit implementation scale.

[0021] Next, the temperature dependency of the switching element during switching operation will be explained using Figures 3 and 4. In the following explanation, it is assumed that an IGBT is used as the switching element.

[0022] Figure 3 shows an example of the waveforms when a switching element is turned on. The horizontal axis represents time, and the vertical axis represents voltage and current. The waveforms of the collector-emitter voltage Vce and collector current Ic are shown when the gate drive voltage VG transitions from low to high, turning on the IGBT.

[0023] The collector-emitter voltage Vce of the dotted waveform k1a and the collector current Ic of the dotted waveform k2a are waveforms when the IGBT is driven at room temperature. The collector-emitter voltage Vce of the solid waveform k1b and the collector current Ic of the solid waveform k2b are waveforms when the IGBT is driven at high temperature.

[0024] At the collector-emitter voltage Vce, in the normal temperature waveform k1a, the high voltage level gradually decreases at time t0 and reaches a constant low voltage level at time t1. On the other hand, in the high temperature waveform k1b, the high voltage level decreases at time t0 and reaches a constant low voltage level at time t2 (t1 < t2). Therefore, when the IGBT is in a high temperature state, the time until the collector-emitter voltage Vce reaches the low voltage level is longer compared to the case of the normal temperature state.

[0025] At the collector current Ic, in the normal temperature waveform k2a, the current amount reaches a peak at time t11. On the other hand, in the high temperature waveform k2b, the current amount reaches a peak at time t12 (t11 < t12). Therefore, when the IGBT is in a high temperature state, the time until the collector current Ic reaches the peak is longer compared to the case of the normal temperature state.

[0026] Thus, the switching drive of the IGBT depends on the temperature during IGBT drive, and the switching speed of the IGBT in the high temperature state is slower than that in the normal temperature state.

[0027] Figure 4 is a diagram showing an example of the temperature dependence of switching loss. The horizontal axis is time, and the vertical axis is the switching loss Eon (mj / pulse). The waveforms k3a, k3b, and k3c respectively show the switching losses when the temperature during the switching drive of the IGBT is 25°C, 125°C, and 150°C. As shown in Figure 4, as the temperature during the switching drive of the IGBT rises to a high temperature, the switching loss of the IGBT increases.

[0028] Thus, when the temperature during the switching drive of the IGBT is in a high temperature state, the switching speed of the IGBT becomes slower than that in the normal temperature state, and the switching loss increases.

[0029] Next, the semiconductor device of the reference example will be described using Figure 5. Figure 5 is a diagram showing an example of the configuration of the semiconductor device of the reference example. The semiconductor device 100 has the function of an IPM and includes a semiconductor chip 110 and a control IC 120.

[0030] The semiconductor chip 110 includes an IGBT3 which is a switching element and a temperature detection diode Dt1. The control IC 120 includes a drive control unit 121 and a temperature detection circuit 122, and the temperature detection circuit 122 includes a constant current source IR, a comparator cmp1, and a reference voltage source V1.

[0031] The control IC 120 also has terminals VGOUT, GND, OC, and OH. The terminal VGOUT is connected to the output terminal of the drive control unit 121 and the gate of the IGBT 3. The terminal GND serves as the ground terminal of the control IC 120, and the emitter of the IGBT 3 is connected to the terminal GND.

[0032] Terminal OC is a terminal for detecting the current flowing between the collector and emitter of IGBT3, and is connected to the sense emitter of IGBT3. Terminal OH is a terminal for detecting the temperature of IGBT3 when it is operating, and is connected to the output end of constant current source IR, the inverting input terminal (-) of comparator cmp1, and the anode of temperature detection diode Dt1.

[0033] The collector of IGBT3 is connected to the positive terminal P, and the cathode of the temperature detection diode Dt1 is connected to GND. A power supply voltage Vcc is applied to the input terminal of the constant current source IR. The positive terminal of the reference voltage source V1 is connected to the non-inverting input terminal (+) of the comparator cmp1, and the negative terminal of the reference voltage source V1 is connected to GND.

[0034] The drive control unit 121 outputs a drive voltage sg3 for controlling the turn-on / turn-off switching of the IGBT 3 based on a switching control signal sg0 transmitted from a control unit (not shown) such as a microcomputer. The drive control unit 121 also has a function of controlling the drive capability of the IGBT 3 based on the level of a temperature detection signal sg2 output from a temperature detection circuit 122.

[0035] The temperature detection circuit 122 detects the temperature of the IGBT 3 and outputs a temperature detection signal sg2 indicating the temperature detection result. During operation of the temperature detection circuit 122, a current It output from a constant current source IR flows through a temperature detection diode Dt1. At this time, the potential generated in the temperature detection diode Dt1 is input to the inverting input terminal (-) of the comparator cmp1 via the terminal OH as a temperature detection voltage Vdi indicating the temperature state of the IGBT 3.

[0036] A reference voltage Voh output from a reference voltage source V1 is applied to the non-inverting input terminal (+) of the comparator cmp1. The comparator cmp1 compares the temperature detection voltage Vdi with the reference voltage Voh, and detects whether the temperature state of the IGBT 3 is a high temperature state based on the comparison result.

[0037] The temperature detection voltage Vdi at the anode of the temperature detection diode Dt1 has a negative temperature characteristic that decreases with an increase in the temperature of the IGBT 3. Therefore, when the level of the temperature detection voltage Vdi becomes equal to or lower than the reference voltage Voh, the comparator cmp1 determines that the temperature state of the IGBT 3 is a high temperature state and outputs an H-level temperature detection signal sg2.

[0038] Furthermore, when the level of the temperature detection voltage Vdi becomes higher than the reference voltage Voh, the comparator cmp1 determines that the temperature state of the IGBT 3 is at room temperature and outputs a temperature detection signal sg2 at an L level. The drive control unit 121 receives the temperature detection signal sg2 output from the temperature detection circuit 122, and changes the output level of the drive voltage sg3 in accordance with the level of the temperature detection signal sg2 to control the drive capability of the IGBT 3.

[0039] In this way, the semiconductor device 100 of the reference example adjusts the driving capability of the IGBT 3 using the temperature detection signal sg2 of the IGBT 3 obtained by comparing the temperature detection voltage Vdi of the temperature detection diode Dt1 with the reference voltage Voh, thereby suppressing a decrease in the switching speed of the IGBT 3 and an increase in switching loss even at high temperatures.

[0040] However, in such a configuration of the semiconductor device 100, a temperature detection circuit 122 and the like must be provided within the control IC 120 to adjust the driving capacity of the IGBT 3, which requires additional circuits and increases the circuit implementation scale.

[0041] Next, the semiconductor device of this embodiment will be described. Note that the upper arm side and the lower arm side have the same configuration and operation, so the configuration and operation of the upper arm side will be described in detail below.

[0042] 6 is a diagram showing an example of a first configuration of a semiconductor device according to this embodiment. The semiconductor device 1-1 includes a semiconductor chip 10-1 and a control IC 20. The semiconductor chip 10-1 includes IGBTs 11a and 11b and FWDs (Free Wheel Diodes) 12a and 12b. The semiconductor chip 10-1 further includes a drive capability control circuit 13 and a thermoelectric element 14a corresponding to the voltage output element 1c. The control IC 20 includes a gate drive circuit 21.

[0043] The drive capacity control circuit 13 also includes a gate resistor Rg and an NMOS transistor m1 as a MOS transistor corresponding to the switch sw. The drive capacity control circuit 13 may be disposed on the control IC 20 side. The thermoelectric element 14a is preferably disposed near the IGBT to detect the temperature of the IGBT.

[0044] Regarding the connection relationship of the constituent elements, the collector of IGBT 11a is connected to the positive terminal P and the cathode of FWD 12a. The emitter of IGBT 11a is connected to the anode of FWD 12a, the output terminal OUT, the collector of IGBT 11b, and the cathode of FWD 12b. The emitter of IGBT 11b is connected to the anode of FWD 12b and the negative terminal N.

[0045] The output terminal of the gate drive circuit 21 is connected to one terminal of the gate resistor Rg and the drain (high potential terminal) of the NMOS transistor m1. The other terminal of the gate resistor Rg is connected to the source (low potential terminal) of the NMOS transistor m1 and the gate of the IGBT 11a. The gate (control terminal) of the NMOS transistor m1 is connected to the voltage output terminal of the thermoelectric element 14a.

[0046] The thermoelectric element 14a is disposed near the IGBT 11a, and is an element that converts the temperature of the IGBT 11a into a voltage (thermoelectric conversion) when the IGBT 11a is operating, and outputs a voltage according to the temperature of the IGBT 11a.

[0047] FIG. 7 is a diagram for explaining the operation of the driving capacity control when the IGBT is in a room temperature state. [Step S21] When the IGBT 11a is operating at room temperature (first temperature), the NMOS transistor m1 is turned off because the voltage output from the thermoelectric element 14a is at a low level. Note that the predetermined level corresponds to, for example, the threshold voltage level required to turn on the NMOS transistor m1.

[0048] [Step S22] The gate drive circuit 21 outputs a drive signal sg1 for controlling the switching of the IGBT 11a based on the switching control signal sg0 transmitted from the control unit.

[0049] [Step S23] The drive signal sg1 flows through the gate resistor Rg because the NMOS transistor m1 is off. Therefore, the drive capability control circuit 13 outputs a gate drive voltage Vg1 (first gate drive voltage) based on the resistance value of the gate resistor Rg, and the gate drive voltage Vg1 is input to the gate of the IGBT 11a.

[0050] FIG. 8 is a diagram for explaining the operation of the driving capacity control when the IGBT is in a high temperature state. [Step S31] When the IGBT 11a is operating in a high temperature state (second temperature state), a predetermined voltage Vt (high level) is output from the thermoelectric element 14a.

[0051] [Step S32] The NMOS transistor m1 is turned on because the voltage Vt of a predetermined level output from the thermoelectric element 14a to the gate of the NMOS transistor m1 is at a high level. [Step S33] The gate drive circuit 21 outputs a drive signal sg1 for controlling the switching of the IGBT 11a based on the switching control signal sg0 transmitted from the control unit.

[0052] [Step S34] Because the NMOS transistor m1 is on, the drive signal sg1 flows through both the gate resistor Rg and the NMOS transistor m1. Therefore, the drive capability control circuit 13 outputs a gate drive voltage Vg2 (second gate drive voltage) based on the combined parallel resistance of the gate resistor Rg and the on-resistance of the NMOS transistor m1, and the gate drive voltage Vg2 is input to the gate of the IGBT 11a.

[0053] In this way, in the semiconductor device 1-1, when it is detected that the IGBT 11a is operating at room temperature, the IGBT 11a is driven by a gate drive voltage Vg1 based on the resistance value of the gate resistor Rg. On the other hand, when it is detected that the IGBT 11a is operating at a high temperature, the NMOS transistor m1 is turned on by the voltage output from the thermoelectric element 14a, and the IGBT 11a is driven by a gate drive voltage Vg2 based on the combined parallel resistance value of the gate resistor Rg and the on-resistance of the NMOS transistor m1.

[0054] The parallel combined resistance of the gate resistor Rg and the on-resistance of the NMOS transistor m1 is smaller than the resistance of the gate resistor Rg alone, so the gate drive voltage Vg2 is smaller than the gate drive voltage Vg1. Therefore, the switching speed at high temperatures is faster than the switching speed at room temperature.

[0055] In this way, the semiconductor device 1-1 adjusts the drive capacity of the IGBT by switching the level of the IGBT gate drive voltage between normal temperature and high temperature. This makes it possible to suppress a decrease in the IGBT switching speed and an increase in switching loss even at high temperatures. Furthermore, since a thermoelectric element is used as the temperature detection mechanism required for adjusting the drive capacity to detect the IGBT temperature, the circuit configuration is simpler than that of the semiconductor device 100 of the reference example, and the circuit implementation scale can be reduced.

[0056] 9 is a diagram showing a first mounting example of circuit components on a semiconductor chip. A semiconductor chip 10a includes a copper base 50, an insulating substrate 51, an IGBT 11, an FWD 12, a gate resistor Rg (chip resistor), and an NMOS transistor m1.

[0057] An insulating substrate 51 is joined to the upper surface of the copper base 50 with a joining material such as solder. Conductive patterns p1, p2, p3, p4, p5, and p6 are laid on the insulating substrate 51. An IGBT 11 and an FWD 12 are mounted on the conductive pattern p1.

[0058] The collector of the IGBT 11 is connected to an external terminal 61 (positive terminal P) and the cathode of the FWD 12 through a conductive pattern p1. The emitter of the IGBT 11 is connected to an anode of the FWD 12 through wires w1 and w2, and is further connected to an external terminal 62 (negative terminal N) through wires w1 and w2 and the conductive pattern p2.

[0059] The drain of the NMOS transistor m1 is connected to the conductive pattern p3. The conductive pattern p3 is also connected to a conductive pattern p4 via a wire w3, and one end of a gate resistor Rg is connected to the conductive pattern p4. The other end of the gate resistor Rg is connected to a conductive pattern p5 via a wire w4.

[0060] The conductive pattern p5 is connected to the source of the NMOS transistor m1 through a wire w5, and further connected to the gate of the IGBT 11 through a wire w6. On the other hand, the thermoelectric element 14a is connected to the conductive pattern p6, and the voltage output terminal of the thermoelectric element 14a is connected to the gate of the NMOS transistor m1 through a wire w7.

[0061] 10 is a diagram showing a second mounting example of circuit components on a semiconductor chip. The semiconductor chip 10b includes a copper base 50, an insulating substrate 51, an IGBT 11, an FWD 12, a gate resistor Rg (chip resistor), and an NMOS transistor m1.

[0062] An insulating substrate 51 is bonded to the upper surface of the copper base 50 with a bonding material such as solder. Conductive patterns p1a, p2, p3, p4, p5, p6, and p7 are laid on the insulating substrate 51. An IGBT 11 and an FWD 12 are mounted on the conductive pattern p1a.

[0063] The collector of the IGBT 11 is connected to an external terminal 61 (positive terminal P) and the cathode of the FWD 12 through a conductive pattern p1a. The emitter of the IGBT 11 is connected to an anode of the FWD 12 through wires w1 and w2, and is further connected to an external terminal 62 (negative terminal N) through wires w1 and w2 and the conductive pattern p2.

[0064] The drain of the NMOS transistor m1 is connected to the conductive pattern p3. The conductive pattern p3 is also connected to a conductive pattern p4 via a wire w3, and one end of a gate resistor Rg is connected to the conductive pattern p4. The other end of the gate resistor Rg is connected to a conductive pattern p5 via a wire w4.

[0065] The conductive pattern p5 is connected to the source of the NMOS transistor m1 through a wire w5, and further connected to the gate of the IGBT 11 through a wire w6. Meanwhile, the thermoelectric element 14a is connected to the conductive pattern p7, and the voltage output terminal of the thermoelectric element 14a is connected to the conductive pattern p6 through a wire w8. The conductive pattern p6 is connected to the gate of the NMOS transistor m1 through a wire w7.

[0066] In this way, the thermoelectric element 14a, the gate resistor Rg and the NMOS transistor m1 in the drive capacity control circuit 13 are built into the semiconductor chip, and furthermore, the thermoelectric element 14a is placed near the IGBT 11. With such mounting, the temperature of the IGBT 11 can be detected with high efficiency, and further, the circuit mounting scale can be reduced.

[0067] 11 is a diagram showing an example of a second configuration of a semiconductor device according to this embodiment. The semiconductor device 1-2 includes a semiconductor chip 10-2 and a control IC 20. The semiconductor chip 10-2 includes IGBTs 11a and 11b and FWDs 12a and 12b. The semiconductor chip 10-2 also includes a drive capability control circuit 13 and a thermopile 14b. The semiconductor device 1-2 uses the thermopile 14b instead of the thermoelectric element 14a, and the other configurations are the same as those shown in FIG. 6.

[0068] The thermopile 14b is disposed near the IGBT 11a so as to be able to detect infrared rays emitted from the IGBT 11a when the IGBT 11a is operating. The thermopile 14b is an element that converts incident energy of the infrared rays emitted from the IGBT 11a into electrical energy and outputs a voltage according to the temperature of the IGBT 11a. The drive capability control circuit 13 switches the gate drive voltage of the IGBT 11a according to the voltage Vt output from the thermopile 14b to control the drive capability of the switching element 11a.

[0069] In this way, the semiconductor device 1-2 also controls the drive capacity of the IGBT by switching the level of the IGBT gate drive voltage between normal temperature and high temperature. This makes it possible to suppress a decrease in switching speed when the IGBT is driven at high temperatures, thereby suppressing an increase in switching loss. Furthermore, since a thermopile is used as the temperature detection mechanism required to adjust the drive capacity to detect the IGBT temperature, the circuit configuration is simpler than that of the semiconductor device 100 of the reference example, and the circuit implementation scale can be reduced.

[0070] Although the embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the scope described in the above embodiments. Furthermore, various modifications and improvements can be made to the above embodiments. Furthermore, the technical scope of the present invention may include forms in which modifications or improvements have been made and their equivalents without departing from the spirit of the present invention. [Explanation of symbols]

[0071] 1. Semiconductor device 1a Switching element 1b Gate drive circuit 1c Voltage output element 1d Drive capacity control circuit Vt voltage Vg Gate drive voltage

Claims

1. A switching element; a gate drive circuit that drives the switching element; a voltage output element that detects the temperature when the switching element is driven and outputs a voltage according to the temperature; a drive capacity control circuit that controls the drive capacity of the switching element by changing a gate drive voltage applied to the gate of the switching element based on the voltage; A semiconductor device having:

2. the driving capability control circuit includes a gate resistor and a switch connected in parallel to the gate resistor and turned on and off in response to the voltage; when the switching element is in a first temperature state, turning off the switch, generating a first gate drive voltage based on a resistance value of the gate resistor, and applying the first gate drive voltage to the gate to drive the switching element with a first drive capability; when the switching element is at a second temperature higher than the first temperature, the switch is turned on to generate a second gate drive voltage based on a parallel combined resistance value of the gate resistor and the on-resistance of the switch, and the second gate drive voltage is applied to the gate to drive the switching element with a second drive capability; The semiconductor device according to claim 1.

3. the switch is a MOS transistor, one end of the gate resistor is connected to a high potential terminal of the MOS transistor and an output terminal of a drive signal of the gate drive circuit; the other end of the gate resistor is connected to a low potential terminal of the MOS transistor and the gate of the switching element; a control terminal of the MOS transistor is connected to an output terminal of the voltage output element from which the voltage is output; 3. The semiconductor device according to claim 2.

4. 2. The semiconductor device according to claim 1, wherein said voltage output element is a thermoelectric element that converts the temperature of said switching element into a voltage and outputs said voltage according to the temperature of said switching element.

5. 2. The semiconductor device according to claim 1, wherein said voltage output element is a thermopile that converts incident energy of infrared rays radiated from said switching element into electric energy and outputs said voltage according to the temperature of said switching element.

6. 2. The semiconductor device according to claim 1, wherein said voltage output element and said driving capability control circuit are mounted on the same chip as said switching element.

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