JP2020094951A - Semiconductor device tester - Google Patents

Abstract

To provide a semiconductor device tester with which it is possible to measure the dv/dt value applied to the switching element of a half-bridge circuit that is the device-under-test (DUT), without requiring the use of an insulating circuit.SOLUTION: A dv/dt testing device alternately turns a P-side MOSFET 101 and an N-side MOSFET 102 on while no load is connected to an AC output terminal 105 of a half-bridge circuit 100 that is the DUT, and measures a current flowing in the half-bridge circuit 100 using a current probe 3 insulated from the half-bridge circuit 100. A computation circuit 5 calculates the dv/dt value of the P-side MOSFET 101 on the basis of the peak value of recovery current of the P-side MOSFET 101 that is measured when the N-side MOSFET 102 is turned on, and calculates the dv/dt value of the N-side MOSFET 102 on the basis of the peak value of recovery current of the N-side MOSFET 102 that is measured when the P-side MOSFET 101 is turned on.SELECTED DRAWING: Figure 1

Description

The present invention relates to a semiconductor device test apparatus, and more particularly to a test apparatus having a half bridge circuit as a test target (DUT: Device Under Test).

For example, a semiconductor device (power semiconductor device) for power control such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) and an IGBT (Insulated Gate Bipolar Transistor) is known. For example, in the case of switching a MOSFET, if the time change amount (dv/dt) of the drain-source voltage at the time of switching exceeds a certain value, an unexpected loss occurs due to the parasitic transistor inside the MOSFET being turned on. In some cases, the MOSFET may be destroyed. The limit value of dv/dt at which the element is not destroyed is called "dv/dt tolerance". Generally, in the process of manufacturing a MOSFET in which dv/dt withstand capability is specified in the specifications, a test for confirming that no breakdown occurs by actually applying dv/dt corresponding to the dv/dt withstand capability of the specifications. Done, thereby ensuring dv/dt tolerance. Hereinafter, this test is referred to as a “dv/dt test”, and a test device that performs the dv/dt test is referred to as a “dv/dt test device”.

Further, Patent Document 1 below discloses a technique of measuring the characteristics of two power transistors forming a half-bridge circuit using a single main current measuring circuit.

JP-A-11-304873

A conventional dv/dt test apparatus using a half-bridge circuit as a test target (DUT) supplies a voltage to the half-bridge circuit to drive the half-bridge circuit while driving the P-side (positive side) MOSFET and the N-side (negative side) MOSFET. A voltage probe is contacted between the drain and source, the drain-source voltage is measured using an oscilloscope, and the measured data of the drain-source voltage is calculated by the arithmetic circuit to make a difference along the time axis. The dv/dt value applied to each MOSFET is calculated. Since the reference potential is different between the drain-source voltage of the P-side MOSFET and the drain-source voltage of the P-side MOSFET, the conventional dv/dt tester requires two oscilloscopes for P-side and N-type. In addition, it is necessary to provide an insulating circuit between the two oscilloscopes and the arithmetic circuit.

Further, by using the high-voltage differential probe, both the drain-source voltage of the P-side MOSFET and the drain-source voltage of the P-side MOSFET can be measured with one oscilloscope. However, the high-voltage differential probe has problems that the frequency characteristic is lower than that of a general voltage probe and that the measurement accuracy is likely to be deteriorated due to external noise. Further, in order to prevent the high voltage differential probe and the oscilloscope from being burned by the surge voltage generated when the DUT is destroyed, an insulating circuit is required even when used in the high voltage differential probe.

As described above, the conventional dv/dt testing device in the related art requires an additional circuit for ensuring insulation between the dv/dt value measuring system and the DUT, which causes a cost increase. ..

The present invention has been made to solve the above problems, and a semiconductor device capable of measuring the dv/dt value applied to the switching element of the half bridge circuit, which is the DUT, without using an insulating circuit. It is an object of the present invention to provide a test device of.

The semiconductor device test apparatus according to the present invention is a semiconductor device test apparatus that includes a half bridge circuit including a positive side switching element and a negative side switching element connected in series between a positive side input terminal and a negative side input terminal. A device, comprising: a power supply circuit for applying a voltage between the positive side input terminal and the negative side input terminal of the half bridge circuit; and the positive side switching element and the negative side switching element of the half bridge circuit. A drive circuit that is alternately turned on, a current sensor that is insulated from the half bridge circuit, detects a current flowing through the half bridge circuit, a current measurement circuit that measures a current detected by the current sensor, and the current. An arithmetic circuit for calculating a dv/dt value, which is a time change amount of a voltage between main electrodes of each of the positive electrode side switching element and the negative electrode side switching element, based on the current measured by the measurement circuit. In the circuit, the power supply circuit applies a voltage between the positive electrode side input terminal and the negative electrode side input terminal, and an AC output terminal which is a connection node between the positive electrode side switching element and the negative electrode side switching element. The positive side switching based on the peak value of the recovery current of the positive side switching element measured by the current measuring circuit when the drive circuit turns on the negative side switching element in the state where no load is connected. The dv/dt value of the element is calculated, and the negative electrode side is based on the peak value of the recovery current of the negative side switching element measured by the current measuring circuit when the drive circuit turns on the positive side switching element. A first arithmetic circuit for calculating the dv/dt value of the switching element is provided.

According to the present invention, since the dv/dt value is calculated based on the recovery current measured by using the current sensor insulated from the half bridge circuit, it is necessary to load the insulation circuit on the dv/dt value measuring system. Absent.

It is a figure which shows the structure of the dv/dt test apparatus which concerns on Embodiment 1. It is a figure which shows the example of a current probe. FIG. 6 is a diagram for explaining the operation of the dv/dt test apparatus according to the first embodiment. FIG. 6 is a diagram for explaining the operation of the dv/dt test apparatus according to the first embodiment. 7 is a graph showing an example of the correlation between the MOSFET dv/dt value and the peak reverse recovery current. It is a graph which shows the example of the correlation of dv/dt value of MOSFET, and recovery time. FIG. 10 is a diagram showing a configuration of an arithmetic circuit included in the dv/dt testing device according to the third embodiment. It is a figure which shows the example of the measurement result of the peak value of recovery current, and dv/dt value when dv/dt test of the same conditions is performed with respect to five samples. It is a figure which shows the structure of the dv/dt testing apparatus which concerns on Embodiment 4. It is a figure which shows the structure of the dv/dt testing apparatus which concerns on Embodiment 5. It is a figure which shows the structure of the dv/dt testing apparatus which concerns on Embodiment 5.

<Embodiment 1>
FIG. 1 is a diagram showing a configuration of a dv/dt test device which is a semiconductor device test device according to the first embodiment. This dv/dt test apparatus uses the half bridge circuit 100 as a DUT.

The half-bridge circuit 100 serving as a DUT includes a P-side MOSFET 101 that is a positive side switching element, an N-side MOSFET 102 that is a negative side switching element, a P-side input terminal 103, an N-side input terminal 104, and an AC output terminal 105. Is equipped with. The P-side MOSFET 101 is connected between the P-side input terminal 103 and the AC output terminal 105, and the N-side MOSFET 102 is connected between the AC output terminal 105 and the N-side input terminal 104. That is, the P-side MOSFET 101 and the N-side MOSFET 102 are connected in series between the P-side input terminal 103 and the N-side input terminal 104, and the AC output terminal 105 is a connection node between the P-side MOSFET 101 and the N-side MOSFET 102. It is connected.

As shown in FIG. 1, the dv/dt test apparatus includes a power supply circuit 1, a drive circuit 2, a current probe 3, an oscilloscope 4, and an arithmetic circuit 5.

The power supply circuit 1 is a DC high-voltage power supply that applies a voltage between the P-side input terminal 103 (drain of the P-side MOSFET 101) and the N-side input terminal 104 (source of the N-side MOSFET 102) of the half bridge circuit 100. The drive circuit 2 alternately turns on the P-side MOSFET 101 and the N-side MOSFET 102 of the half bridge circuit 100.

As shown in FIG. 1, the drive circuit 2 includes a drive control circuit 10, a P-side gate insulation circuit 11a, a P-side gate driver 11, an N-side gate insulation circuit 12a and an N-side gate driver 12. The drive control circuit 10 generates control signals for the P-side MOSFET 101 and the N-side MOSFET 102. The control signal of the P-side MOSFET 101 generated by the drive control circuit 10 is input to the P-side gate driver 11 via the P-side gate insulation circuit 11a, and driven by the P-side gate driver 11 with the potential of the AC output terminal 105 as a reference. After being converted into a signal, it is input to the gate of the P-side MOSFET 101. The control signal of the N-side MOSFET 102 generated by the drive control circuit 10 is input to the N-side gate driver 12 via the N-side gate insulating circuit 12a, and the N-side gate driver 12 uses the potential of the N-side input terminal 104 as a reference. After being converted into a drive signal to be input to the gate of the N-side MOSFET 102.

The current probe 3 is a current sensor that has a configuration insulated from the half bridge circuit 100 and detects a current flowing through a wiring (bus bar) that connects the half bridge circuit 100 and the power supply circuit 1. As the current probe 3, for example, as shown in FIG. 2, it is possible to use a probe that is physically separated from the wiring bar of the bus bar to ensure insulation from the half bridge circuit 100. Examples of such a current probe 3 include a current transformer (CT) manufactured by Pearson and a Rogowski coil manufactured by PEM.

Although the oscilloscope 4 observes the waveform of the current detected by the current probe 3, it also functions as a current measuring circuit that measures the current detected by the current probe 3. The data of the measured current value measured by the oscilloscope 4 is sent to the arithmetic circuit 5.

The arithmetic circuit 5 calculates a dv/dt value which is a time change amount of the drain-source voltage (main electrode voltage) of each of the P-side MOSFET 101 and the N-side MOSFET 102 based on the current measured by the oscilloscope 4.

Next, the operation of the dv/dt test apparatus according to the first embodiment will be described. The dv/dt test using the dv/dt test apparatus is in a state in which a load is not connected to the AC output terminal 105 of the half-bridge circuit 100 that is a DUT, that is, a state in which nothing is connected to the AC output terminal 105. Done in. In the dv/dt test, the power supply circuit 1 applies a voltage between the P-side input terminal 103 and the N-side input terminal 104 of the half bridge circuit 100, and the drive circuit 2 causes the P-side MOSFET 101 and the N-side MOSFET 102. Are turned on alternately.

FIG. 3 shows the gate-source voltage (P-Vgs) of the P-side MOSFET 101, the gate-source voltage (N-Vgs) of the N-side MOSFET 102, and the drain-source of the P-side MOSFET 101 during the dv/dt test. The respective waveforms of the voltage (P-Vds), the drain-source voltage (N-Vds) of the N-side MOSFET 102, and the current flowing through the half bridge circuit 100 (current flowing through the bus) are shown. 4 is an enlarged view of the waveform of the drain-source voltage of the P-side MOSFET 101 or N-side MOSFET 102 and the waveform of the current flowing through the half bridge circuit 100 shown in FIG.

The drive circuit 2 alternately sets the gate-source voltage (P-Vgs) of the P-side MOSFET 101 and the gate-source voltage (N-Vgs) of the N-side MOSFET 102 to make the P-side MOSFET 101. And the P-side MOSFET 101 are alternately turned on.

In this case, the drain-source voltage of the P-side MOSFET 101 falls and the drain-source voltage of the N-side MOSFET 102 rises at the timing when the P-side MOSFET 101 turns on. At the timing when the P-side MOSFET 101 is turned off, the drain-source voltage of the P-side MOSFET 101 and the drain-source voltage of the N-side MOSFET 102 are maintained.

Further, at the timing when the N-side MOSFET 102 is turned on, the drain-source voltage of the N-side MOSFET 102 falls and the drain-source voltage of the P-side MOSFET 101 rises. At the timing when the N-side MOSFET 102 is turned off, the drain-source voltage of the P-side MOSFET 101 and the drain-source voltage of the N-side MOSFET 102 are maintained.

In the P-side MOSFET 101 and the N-side MOSFET 102, the breakdown voltage of the body diode between the drain and the source is restored when the ON-to-OFF transition occurs. Therefore, when the P-side MOSFET 101 turns on, the recovery current of the N-side MOSFET 102 flows, and when the N-side MOSFET 102 turns on, the recovery current of the P-side MOSFET 101 flows. All of these recovery currents flow through the wiring (bus) that connects the power supply circuit 1 and the half bridge circuit 100, so they are detected by the current probe 3 and measured by the oscilloscope 4.

Therefore, the arithmetic circuit 5 determines that the current measured by the oscilloscope 4 when the N-side MOSFET 102 is turned on is the recovery current of the P-side MOSFET 101, and the current measured by the oscilloscope 4 when the P-side MOSFET 101 is turned on. , Recovery current of the N-side MOSFET 102 is determined.

Here, there is a correlation between the dv/dt value of the MOSFET and the peak value of the recovery current (also referred to as “peak reverse recovery current I _rr ”). FIG. 5 shows an example of the correlation between the dv/dt value of the MOSFET and the peak reverse recovery current I _rr . In FIG. 5, the function representing the correlation between the dv/dt value and the peak reverse recovery current I _rr is represented by an approximate straight line. The arithmetic circuit 5 calculates the dv/dt value of the P-side MOSFET ₁₀₁ from the peak reverse recovery current I _rr of the P-side MOSFET ₁₀₁ , using the conversion formula expressing this correlation, and calculates it from the peak reverse recovery current I _{rr of} the N-side MOSFET _102. , The dv/dt value of the N-side MOSFET 102 is calculated.

The correlation between the dv/dt value and the peak reverse recovery current I _rr may be obtained by a method other than linear approximation. For example, when the internal inductance of the dv/dt testing device affects the peak reverse recovery current I _rr , it may be preferable to obtain the correlation by quadratic approximation.

As described above, in the dv/dt test apparatus according to the first embodiment, the recovery current generated in the half bridge circuit 100 that is the DUT is measured using the current probe 3 insulated from the half bridge circuit 100, and the measurement result is obtained. From this, the dv/dt value applied to the P-side MOSFET 101 and the N-side MOSFET 102 of the half bridge circuit 100 is calculated. Therefore, an additional circuit for ensuring insulation between the dv/dt value measurement system and the DUT is not required, and the cost increase of the dv/dt test apparatus can be suppressed.

<Second Embodiment>
The dv/dt value of the MOSFET also has a correlation with the time until the recovery current disappears, that is, the recovery time (also referred to as “reverse recovery time t _rr ”). FIG. 6 is a graph showing an example of the correlation between the dv/dt value of the MOSFET and the reverse recovery time _trr .

Therefore, in the second embodiment, the arithmetic circuit 5 calculates the dv / dt value of P-side MOSFET 101 based on the reverse recovery time _{t rr} of P-side MOSFET 101, on the basis of the reverse recovery time _{t rr} of N-side MOSFET 102 N The dv/dt value of the side MOSFET 102 is calculated. Other configurations and operations are the same as those of the dV/dt test apparatus according to the first embodiment.

That is, in the dv/dt test performed by the dV/dt test apparatus according to the second embodiment, the power supply circuit 1 applies a voltage between the P-side input terminal 103 and the N-side input terminal 104, as in the first embodiment. The load is not connected to the AC output terminal that is the connection node between the P-side MOSFET 101 and the N-side MOSFET 102. The arithmetic circuit 5 obtains the reverse recovery time trr of the P-side MOSFET 101 from the waveform of the recovery current of the P-side MOSFET 101 measured by the oscilloscope 4 when the drive circuit 2 turns on the N-side MOSFET ₁₀₂ , and the reverse recovery time thereof. The dv/dt value of the P-side MOSFET 101 is calculated based on t _rr . Further, the arithmetic circuit 5 obtains the reverse recovery time trr of the N-side MOSFET 102 from the waveform of the recovery current of the N-side MOSFET 102 measured by the oscilloscope 4 when the drive circuit 2 turns on the P-side MOSFET ₁₀₁ , and the reverse recovery thereof. The dv/dt value of the N-side MOSFET 102 is calculated based on the time _trr .

Also in the dv/dt test apparatus according to the second embodiment, the recovery current generated in the half bridge circuit 100, which is the DUT, is measured using the current probe 3 insulated from the half bridge circuit 100, and from the measurement result, P The dv/dt applied to the side MOSFET 101 and the N side MOSFET 102 is calculated. Therefore, as in the first embodiment, an additional circuit for ensuring the insulation between the dv/dt value measurement system and the DUT is not required, and the cost increase of the dv/dt test apparatus can be suppressed.

<Third Embodiment>
In the third embodiment, the arithmetic circuit 5 uses the dv/dt value calculated from the peak reverse recovery current I _rr of the MOSFET as in the first embodiment and the reverse recovery time t _rr of the MOSFET as in the second embodiment. The dv/dt value calculated from the above is calculated, and the average value of the two is calculated as the final MOSFET dv/dt value.

Specifically, the arithmetic circuit 5 according to the third embodiment includes a first arithmetic circuit 51, a second arithmetic circuit 52, and an average value arithmetic circuit 53, as shown in FIG. 7.

In the dv/dt test, the first arithmetic circuit 51 detects the P-side MOSFET ₁₀₁ based on the peak reverse recovery current I _rr of the P-side MOSFET 101 measured by the oscilloscope 4 when the drive circuit 2 turns on the N-side MOSFET 102. The dv/dt value is calculated, and the dv/dt value of the N-side MOSFET 102 is calculated based on the peak reverse recovery current I _rr of the N-side MOSFET 102 measured by the oscilloscope 4 when the drive circuit 2 turns on the P-side MOSFET 101. To do.

In the dv/dt test, the second arithmetic circuit 52 uses the reverse recovery time _trr determined from the waveform of the recovery current of the P-side MOSFET 101 measured by the oscilloscope 4 when the drive circuit 2 turns on the N-side MOSFET ₁₀₂ . The dv/dt value of the P-side MOSFET 101 is calculated based on the reverse recovery time t _rr obtained from the waveform of the recovery current of the N-side MOSFET 102 measured by the oscilloscope 4 when the drive circuit 2 turns on the P-side MOSFET ₁₀₁ . Based on this, the dv/dt value of the N-side MOSFET 102 is calculated.

The average value calculation circuit 53 calculates the average value of the dv/dt value of the P-side MOSFET 101 calculated by the first calculation circuit 51 and the dv/dt value of the P-side MOSFET 101 calculated by the second calculation circuit 52. The final dv/dt value of the P-side MOSFET 101 is calculated, and the dv/dt value of the N-side MOSFET 102 calculated by the first arithmetic circuit 51 and the dv/dt value of the N-side MOSFET 102 calculated by the second arithmetic circuit 52 are calculated. The average value with the dt value is calculated as the final dv/dt value of the N-side MOSFET 102.

For example, the pulse noise generated by the switching of the P-side MOSFET 101 and the N-side MOSFET 102 may be superimposed on the measured value of the recovery current to cause a measurement error, but it is the reverse of the dv/dt value calculated from the reverse recovery current I _rr. By taking the average with the dv/dt value calculated from the recovery time _trr, the error due to pulse noise can be reduced. Thereby, the accuracy and reliability of the measurement result of the dv/dt value are improved.

<Embodiment 4>
Even if the dv/dt test is performed under the same conditions, the dv/dt applied to the MOSFET of the DUT varies due to variations in the characteristics of the MOSFET elements. For example, FIG. 8 shows the measurement results of the peak reverse recovery current I _rr and dv/dt when the dv/dt test under the same conditions is performed on five samples, but there are variations in the measured values.

In order to apply the target value dv/dt to all DUTs, the test conditions may be corrected according to the characteristics of each MOSFET. However, for that purpose, it is necessary to measure the characteristics of the MOSFET of the DUT in advance and further change the condition for each DUT, which causes an increase in work load, an increase in cost, and a decrease in productivity.

In the fourth embodiment, in order to solve this problem, the dv/dt test apparatus reduces the difference between the measured value of dv/dt and the set value (target value) so that the output voltage of the power supply circuit 1 or Feedback control for the output voltage of the drive circuit 2 is performed.

FIG. 9 is a diagram showing the configuration of the dv/dt test apparatus according to the fourth embodiment. The configuration of the dv/dt test device in FIG. 9 is obtained by adding a feedback control circuit 6 as a first feedback control circuit to the configuration in FIG. In the feedback control circuit 6, the drive circuit 2 is arranged in the half bridge circuit 100 so that the difference between the dv/dt value of the P-side MOSFET 101 or the N-side MOSFET 102 calculated by the arithmetic circuit 5 and the set value of dv/dt is reduced. The voltage of the drive signal supplied (gate-source voltage of the P-side MOSFET 101 and the N-side MOSFET 102) or the voltage supplied from the power supply circuit 1 to the half bridge circuit 100 is controlled.

According to the dv/dt test apparatus according to the fourth embodiment, the output voltage of the power supply circuit 1 or the output voltage of the drive circuit 2 is automatically adjusted so as to reduce the difference between the measured value and the set value of dv/dt. Since it is controlled, it is possible to perform a dv/dt test with little variation.

The feedback control circuit 6 of this embodiment can be applied to the second and third embodiments. When applied to the third embodiment, the feedback control circuit 6 sets the dv/dt value of the P-side MOSFET 101 or the N-side MOSFET 102 calculated by the average value calculation circuit 53 of the calculation circuit 5 and the set value of dv/dt. Feedback control is performed on the output voltage of the power supply circuit 1 or the output voltage of the drive circuit 2 so as to reduce the difference.

<Embodiment 5>
If the DUT goes into an abnormal mode during the dv/dt test, the temperature of the DUT may rise, resulting in destruction. Therefore, in the fifth embodiment, the dv/dt test device measures the temperature of the DUT and performs feedback control of the gate-source voltage or the power supply voltage so that the temperature does not exceed a predetermined threshold value. This prevents the DUT from being destroyed.

FIG. 10 is a diagram showing the configuration of the dv/dt test apparatus according to the fifth embodiment. The configuration of the dv/dt test device in FIG. 10 is obtained by adding a feedback control circuit 6 as a second feedback control circuit and a temperature sensor 7 to the configuration in FIG. The temperature sensor 7 measures the temperature of the half bridge circuit 100, which is a DUT, and inputs the measured value to the feedback control circuit 6. Based on the temperature of the half bridge circuit 100 measured by the temperature sensor 7, the feedback control circuit 6 prevents the temperature of the half bridge circuit 100 from exceeding a predetermined threshold value or the output voltage of the power supply circuit 1 or the drive circuit 2. Feedback control for the output voltage is performed.

With the dv/dt test apparatus according to the fifth embodiment, the output voltage of the power supply circuit 1 or the output voltage of the drive circuit 2 is automatically controlled so that the temperature of the DUT does not exceed a predetermined threshold value. Therefore, destruction of the DUT can be prevented.

The feedback control circuit 6 according to the present embodiment is also applicable to the second to fourth embodiments. When applied to the fourth embodiment, the dv/dt value calculated by the arithmetic circuit 5 and the temperature of the half bridge circuit 100 measured by the temperature sensor 7 are input to the feedback control circuit 6 as shown in FIG. The feedback control circuit 6 reduces the difference between the dv/dt value of the P-side MOSFET 101 or the N-side MOSFET 102 and the set value of dv/dt, and the temperature of the half bridge circuit 100 does not exceed a predetermined threshold value. Thus, the output voltage of the power supply circuit 1 or the output voltage of the drive circuit 2 is controlled.

<Modification>
Although the dv/dt test apparatus has been described in the above embodiments, the test apparatus uses a drain-source current (main electrode current) that occurs during switching of the P-side MOSFET 101 and the N-side MOSFET 102 of the half-bridge circuit 100 that is a DUT. It is also possible to use a test device (di/dt test device) for testing the withstand amount of () against the time change amount (di/dt). There is also a correlation between the di/dt value of the MOSFET, the peak value of the recovery current (peak reverse recovery current I _rr ) and the recovery time (reverse recovery time t _rr ). In the case of the di/dt test apparatus, the arithmetic circuit 5 uses the conversion equation representing the correlation to calculate the peak reverse recovery current I _rr or the reverse recovery time _trr of the P-side MOSFET ₁₀₁ from the di/dt of the P-side MOSFET 101. The value may be calculated, and the di/dt value of the N-side MOSFET 102 may be calculated from the peak reverse recovery current I _{rr of} the N-side MOSFET ₁₀₂ or the reverse recovery time t _rr . Further, similarly to the third embodiment, the arithmetic circuit 5 calculates the di/dt value calculated from the peak reverse recovery current I _{rr of} the MOSFET and the di/dt value calculated from the reverse recovery time t _{rr of the} MOSFET. Alternatively, the average value of the two may be calculated as the final MOSFET di/dt value. Furthermore, the feedback control described in the fourth and fifth embodiments can be applied to the di/dt testing device.

Further, in each of the embodiments, a MOSFET is representatively shown as a switching element that constitutes the half-bridge circuit 100 of the DUT. By the way, in products using an IGBT as a switching element, an FWD (Free Wheeling Diode) is often connected in antiparallel to the IGBT. There is also a switching element called RC-IGBT (Reverse-conducting IGBT) in which an FWD function is built in an IGBT chip. Even when the switching elements forming the half bridge circuit 100 are these IGBTs, the respective embodiments are applicable as in the case of the MOSFETs. Further, the semiconductor material of the switching element may be a wide band gap semiconductor such as SiC or GaN other than silicon.

In the present invention, the respective embodiments can be freely combined, or the respective embodiments can be appropriately modified or omitted within the scope of the invention.

1 power supply circuit, 2 drive circuit, 3 current probe, 4 oscilloscope, 5 arithmetic circuit, 6 feedback control circuit, 7 temperature sensor, 10 drive control circuit, 11 P side gate driver, 12 N side gate driver, 11a P side gate insulation Circuit, 12a N-side gate insulation circuit, 51 first arithmetic circuit, 52 second arithmetic circuit, 53 average value arithmetic circuit, 100 half bridge circuit, 101 P-side MOSFET, 102 N-side MOSFET, 103 P-side input terminal, 104 N-side input terminal, 105 AC output terminal.

Claims (16)

A testing device for a semiconductor device, wherein a half bridge circuit including a positive side switching element and a negative side switching element connected in series between a positive side input terminal and a negative side input terminal is a test target,
A power supply circuit for applying a voltage between the positive side input terminal and the negative side input terminal of the half bridge circuit;
A drive circuit for alternately turning on the positive side switching element and the negative side switching element of the half bridge circuit,
A current sensor that is insulated from the half bridge circuit and detects a current flowing through the half bridge circuit,
A current measuring circuit for measuring the current detected by the current sensor,
An arithmetic circuit for calculating a dv/dt value which is a time change amount of a voltage between main electrodes of each of the positive electrode side switching element and the negative electrode side switching element based on the current measured by the current measuring circuit;
Equipped with
The arithmetic circuit is
The power supply circuit applies a voltage between the positive side input terminal and the negative side input terminal, and a load is connected to an AC output terminal that is a connection node between the positive side switching element and the negative side switching element. When the drive circuit turns on the negative electrode side switching element in the state where the current is not applied, the dv of the positive electrode side switching element is calculated based on the peak value of the recovery current of the positive electrode side switching element measured by the current measuring circuit. /Dt value is calculated, and based on the peak value of the recovery current of the negative electrode side switching element measured by the current measuring circuit when the drive circuit turns on the positive electrode side switching element, the negative electrode side switching element a first arithmetic circuit for calculating the dv/dt value is provided,
Semiconductor device testing equipment. In order to reduce the difference between the dv/dt value of the positive side switching element or the negative side switching element calculated by the first arithmetic circuit and its set value, the output voltage of the power supply circuit or the drive circuit Further comprising a first feedback control circuit for controlling the output voltage,
The semiconductor device testing apparatus according to claim 1. The arithmetic circuit is
When the power supply circuit applies a voltage between the positive electrode side input terminal and the negative electrode side input terminal, and the load is not connected to the AC output terminal, the drive circuit operates the negative electrode side switching element. The dv/dt value of the positive side switching element is calculated based on the recovery time obtained from the waveform of the recovery current of the positive side switching element measured by the current measuring circuit when turned on, and the drive circuit Calculating a dv/dt value of the negative electrode side switching element based on a recovery time obtained from a waveform of a recovery current of the negative electrode side switching element measured by the current measuring circuit when the positive electrode side switching element is turned on. 2 arithmetic circuits,
The average value of the dv/dt value of the positive electrode side switching element calculated by the first arithmetic circuit and the dv/dt value of the positive electrode side switching element calculated by the second arithmetic circuit is defined as the positive electrode side. The dv/dt value of the switching element is calculated as the dv/dt value of the negative side switching element calculated by the first arithmetic circuit, and the dv/dt value of the negative side switching element calculated by the second arithmetic circuit. an average value calculation circuit for calculating an average value with the dt value as a dv/dt value of the negative electrode side switching element;
Further comprising,
The semiconductor device testing apparatus according to claim 1. The output voltage of the power supply circuit or the output of the drive circuit so as to reduce the difference between the dv/dt value of the positive side switching element or the negative side switching element calculated by the average value calculation circuit and its set value. Further comprising a first feedback control circuit for controlling the voltage,
The semiconductor device testing apparatus according to claim 3. A temperature sensor for measuring the temperature of the half bridge circuit,
It further comprises a second feedback control circuit that controls the output voltage of the power supply circuit or the output voltage of the drive circuit so that the temperature of the half bridge circuit measured by the temperature sensor does not exceed a predetermined threshold value. ,
The semiconductor device testing apparatus according to claim 1. A testing device for a semiconductor device, wherein a half bridge circuit including a positive side switching element and a negative side switching element connected in series between a positive side input terminal and a negative side input terminal is a test target,
A power supply circuit for applying a voltage between the positive side input terminal and the negative side input terminal of the half bridge circuit;
A drive circuit for alternately turning on the positive side switching element and the negative side switching element of the half bridge circuit,
A current sensor that is insulated from the half bridge circuit and detects a current flowing through the half bridge circuit,
A current measuring circuit for measuring the current detected by the current sensor,
An arithmetic circuit for calculating a dv/dt value which is a time change amount of a voltage between main electrodes of each of the positive electrode side switching element and the negative electrode side switching element based on the current measured by the current measuring circuit;
Equipped with
The arithmetic circuit is
The power supply circuit applies a voltage between the positive side input terminal and the negative side input terminal, and a load is connected to an AC output terminal that is a connection node between the positive side switching element and the negative side switching element. The positive electrode side based on the recovery time obtained from the waveform of the recovery current of the positive electrode side switching element measured by the current measuring circuit when the driving circuit turns on the negative electrode side switching element in the state where the positive electrode side is not turned on. A recovery time calculated from the dv/dt value of the switching element and obtained from the waveform of the recovery current of the negative side switching element measured by the current measuring circuit when the drive circuit turns on the positive side switching element. Calculating the dv/dt value of the negative electrode side switching element based on
Semiconductor device testing equipment. The output voltage of the power supply circuit or the output voltage of the drive circuit is adjusted so as to reduce the difference between the dv/dt value of the positive side switching element or the negative side switching element calculated by the arithmetic circuit and its set value. Further comprising a first feedback control circuit for controlling,
The semiconductor device testing apparatus according to claim 6. A temperature sensor for measuring the temperature of the half bridge circuit,
It further comprises a second feedback control circuit that controls the output voltage of the power supply circuit or the output voltage of the drive circuit so that the temperature of the half bridge circuit measured by the temperature sensor does not exceed a predetermined threshold value. ,
A semiconductor device testing apparatus according to claim 6 or 7. A testing device for a semiconductor device, wherein a half bridge circuit including a positive side switching element and a negative side switching element connected in series between a positive side input terminal and a negative side input terminal is a test target,
A power supply circuit for applying a voltage between the positive side input terminal and the negative side input terminal of the half bridge circuit;
A drive circuit for alternately turning on the positive side switching element and the negative side switching element of the half bridge circuit,
A current sensor that is insulated from the half bridge circuit and detects a current flowing through the half bridge circuit,
A current measuring circuit for measuring the current detected by the current sensor,
An arithmetic circuit for calculating a di/dt value, which is a time change amount of the current between main electrodes of each of the positive electrode side switching element and the negative electrode side switching element, based on the current measured by the current measuring circuit;
Equipped with
The arithmetic circuit is
The power supply circuit applies a voltage between the positive side input terminal and the negative side input terminal, and a load is connected to an AC output terminal that is a connection node between the positive side switching element and the negative side switching element. When the drive circuit turns on the negative electrode side switching element in the state where it is not turned on, the di of the positive electrode side switching element is determined based on the peak value of the recovery current of the positive electrode side switching element measured by the current measuring circuit. /Dt value is calculated, and based on the peak value of the recovery current of the negative electrode side switching element measured by the current measuring circuit when the drive circuit turns on the positive electrode side switching element, the negative electrode side switching element a first arithmetic circuit for calculating a di/dt value is provided,
Semiconductor device testing equipment. In order to reduce the difference between the di/dt value of the positive side switching element or the negative side switching element calculated by the first arithmetic circuit and its set value, the output voltage of the power supply circuit or the drive circuit Further comprising a first feedback control circuit for controlling the output voltage,
The semiconductor device testing apparatus according to claim 9. The arithmetic circuit is
When the power supply circuit applies a voltage between the positive electrode side input terminal and the negative electrode side input terminal, and the load is not connected to the AC output terminal, the drive circuit operates the negative electrode side switching element. The di/dt value of the positive electrode side switching element is calculated based on the recovery time obtained from the waveform of the recovery current of the positive electrode side switching element measured by the current measuring circuit when turned on, and the drive circuit Calculating a di/dt value of the negative electrode side switching element based on a recovery time obtained from a waveform of a recovery current of the negative electrode side switching element measured by the current measuring circuit when the positive electrode side switching element is turned on. 2 arithmetic circuits,
An average value of the di/dt value of the positive side switching element calculated by the first arithmetic circuit and the di/dt value of the positive side switching element calculated by the second arithmetic circuit is defined as the positive side. Calculated as the di/dt value of the switching element, and the di/dt value of the negative side switching element calculated by the first arithmetic circuit and the di/dt value of the negative side switching element calculated by the second arithmetic circuit. an average value calculation circuit for calculating an average value with the dt value as a di/dt value of the negative electrode side switching element;
Further comprising,
The semiconductor device testing apparatus according to claim 9. The output voltage of the power supply circuit or the output of the drive circuit so as to reduce the difference between the di/dt value of the positive side switching element or the negative side switching element calculated by the average value calculation circuit and its set value. Further comprising a first feedback control circuit for controlling the voltage,
The semiconductor device testing apparatus according to claim 11. A temperature sensor for measuring the temperature of the half bridge circuit,
It further comprises a second feedback control circuit that controls the output voltage of the power supply circuit or the output voltage of the drive circuit so that the temperature of the half bridge circuit measured by the temperature sensor does not exceed a predetermined threshold value. ,
The semiconductor device testing apparatus according to claim 9. A testing device for a semiconductor device, wherein a half bridge circuit including a positive side switching element and a negative side switching element connected in series between a positive side input terminal and a negative side input terminal is a test target,
A power supply circuit for applying a voltage between the positive side input terminal and the negative side input terminal of the half bridge circuit;
A drive circuit for alternately turning on the positive side switching element and the negative side switching element of the half bridge circuit,
A current sensor that is insulated from the half bridge circuit and detects a current flowing through the half bridge circuit,
A current measuring circuit for measuring the current detected by the current sensor,
An arithmetic circuit for calculating a di/dt value, which is a time change amount of the current between main electrodes of each of the positive electrode side switching element and the negative electrode side switching element, based on the current measured by the current measuring circuit;
Equipped with
The arithmetic circuit is
The power supply circuit applies a voltage between the positive side input terminal and the negative side input terminal, and a load is connected to an AC output terminal that is a connection node between the positive side switching element and the negative side switching element. The positive electrode side based on the recovery time obtained from the waveform of the recovery current of the positive electrode side switching element measured by the current measuring circuit when the driving circuit turns on the negative electrode side switching element in the state where the positive electrode side is not turned on. The recovery time calculated from the di/dt value of the switching element and obtained from the waveform of the recovery current of the negative side switching element measured by the current measuring circuit when the drive circuit turns on the positive side switching element Calculating the di/dt value of the negative side switching element based on
Semiconductor device testing equipment. The output voltage of the power supply circuit or the output voltage of the drive circuit is adjusted so as to reduce the difference between the di/dt value of the positive side switching element or the negative side switching element calculated by the arithmetic circuit and its set value. Further comprising a first feedback control circuit for controlling,
The semiconductor device testing apparatus according to claim 14. A temperature sensor for measuring the temperature of the half bridge circuit,
It further comprises a second feedback control circuit that controls the output voltage of the power supply circuit or the output voltage of the drive circuit so that the temperature of the half bridge circuit measured by the temperature sensor does not exceed a predetermined threshold value. ,
The semiconductor device testing apparatus according to claim 14 or 15.

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