JP2016118399A - Testing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a testing apparatus capable of further promptly interrupting the supply of power to a measurement target in response to the occurrence of an abnormality, as compared with before.SOLUTION: A testing apparatus 1 for testing a semiconductor 2 includes: a driving signal output unit 5 that supplies a driving signal to a gate of the semiconductor 2; a power supply 4 that supplies a driving power (V1) to the semiconductor 2; a switch circuit 7 that interrupts the supply of the driving power (V1) to the semiconductor 2; and an abnormality detection unit 6 that detects an abnormality of the semiconductor 2 and drives the switch circuit 7. The abnormality detection unit 6 detects an abnormality of the semiconductor 2 on the basis of a gate voltage Vg of the semiconductor 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a test apparatus for testing, for example, a high voltage, large current insulated gate bipolar transistor (IGBT), a power MOSFET, etc. used for driving a large output motor or the like.

  Conventionally, in a semiconductor manufacturing process, various tests are executed by a test apparatus in shipping inspection or the like. Regarding such a test, a measuring method is defined in JEC-2407-2007 etc. for high voltage and large current IGBTs.

  In such a test apparatus, conventionally, an abnormality of the test object is detected by the drive current of the test object and the power supply is shut off (for example, Patent Document 1), thereby protecting the test apparatus.

  However, with the conventional power shut-off method in a test apparatus, it takes time to shut down the power after the occurrence of an abnormality and the drive current starts to decrease. As a result, there is a problem that the measurement target, the measurement jig, etc. are damaged. It was. Accordingly, it is desired that the supply of power to the test object can be cut off more quickly than in the past.

JP 2012-127813 A

  The present invention has been made in consideration of the above points, and intends to propose a test apparatus that can cut off the supply of power to a measurement object more quickly than before due to the occurrence of an abnormality. .

In order to solve the problem, in the invention of claim 1,
In test equipment for testing semiconductors,
A drive signal output unit for supplying a drive signal to the gate of the semiconductor;
A power supply for supplying driving power to the semiconductor;
A switch circuit that cuts off the supply of the driving power to the semiconductor;
An abnormality detection unit for detecting an abnormality of the semiconductor and driving the switch circuit;
The abnormality detection unit
A test apparatus for detecting an abnormality of the semiconductor based on a gate voltage of the semiconductor.

  In a semiconductor, the drive current and the drive voltage change suddenly due to the occurrence of an abnormality, and an abnormal voltage is generated in the gate voltage due to the effect of this change. In addition, the abnormality of the gate voltage may be detected in a shorter time than the abnormality detection by the drive current. Thus, according to the configuration of the first aspect, in such a case, an abnormality can be detected at an earlier point in time than in the past, and the supply of power to the measurement target can be shut off more quickly than in the past. be able to.

The invention of claim 2 is the configuration of claim 1,
The abnormality detection unit
By determining the gate voltage of the semiconductor based on a determination reference value, an abnormality of the semiconductor is detected based on the gate voltage of the semiconductor.

  According to the configuration of the second aspect, the abnormality can be detected at an earlier point in time than the conventional configuration with a more specific configuration.

The invention of claim 3 is the structure of claim 1 or claim 2,
The abnormality detection unit
Further, an abnormality of the semiconductor is detected based on the driving current of the semiconductor.

  According to the configuration of the third aspect, even when the abnormal phenomenon does not appear rapidly in the gate voltage, the test apparatus can be protected by preventing a significant increase in the drive current due to the abnormality.

  According to the present invention, it is possible to cut off the supply of power to the measurement object more quickly than before due to the occurrence of an abnormality.

1 is a diagram illustrating a test apparatus according to a first embodiment of the present invention. FIG. 2 is a signal waveform diagram for explaining operations in the test apparatus of FIG. 1.

  Hereinafter, embodiments of the present invention will be described in detail.

[First Embodiment]
FIG. 1 is a diagram showing a test apparatus according to the first embodiment of the present invention. The test apparatus 1 is connected to the IGBT module via a measurement jig, and tests the IGBT 2 constituting the IGBT module. The IGBT module is a module in which a plurality of IGBTs 2 are housed, and a protective diode 3 is provided in parallel with each IGBT 2.

  For this reason, in this test apparatus 1, the power supply 4 that supplies the drive power to the IGBT 2 to be tested, the switch circuit 7 that shuts off the drive power supply from the power supply 4 to the IGBT 2 under the control of the abnormality detection unit 6, and the IGBT 2 Gate drive unit (Gate-DR Unit) 5, which is a drive signal output unit that supplies a test drive signal to the gate, a measurement circuit that measures each terminal voltage of the IGBT 2 that changes according to the drive signal, and a measurement result of the measurement circuit is aggregated A controller or the like is provided. As a result, the test apparatus 1 is configured to be able to test the IGBT 2 that is the test target according to various test items.

  In the test apparatus 1, the abnormality detection unit 6 detects an abnormality of the IGBT 2 that is the test target based on the gate voltage of the IGBT 2, and shuts off the drive power supply to the IGBT 2 under the control of the switch circuit 7. As a result, the test apparatus 1 shuts off the supply of power to the measurement object more quickly than before due to the occurrence of an abnormality. More specifically, the abnormality detection unit 6 determines the gate voltage Vg based on the determination reference value, drives the switch circuit 7 based on the determination result S1 obtained as a result, and shuts off the driving power supply.

  That is, as shown in FIG. 2, when the IGBT 2 is driven by raising the gate voltage Vg (FIG. 2B) by the gate signal, the voltage between the terminals of the IGBT 2 (the drain-source voltage and the drive voltage) V1 ( 2A) and the drive current I1 (FIG. 2E) change according to the gate voltage Vg. Note that the amount of fluctuation of the inter-terminal voltage V1 of the IGBT 2 depends on the output resistance of the power supply 4 and the internal resistance of the switch circuit 7.

  When the IGBT 2 is driven in this way and, for example, an abnormality occurs in the IGBT 2 at the time t1, the drive current I1 of the IGBT 2 rapidly increases and the inter-terminal voltage V1 rapidly changes. The inter-terminal voltage V <b> 1 after abnormality exhibits various changes depending on the characteristics of the power supply 4.

  In the conventional test apparatus, the drive current I1 is determined based on the determination reference value TH1 to detect the abnormality of the test target and stop the supply of power, but in this case, it is necessary to detect the abnormality from the occurrence of the abnormality. The supply of power is stopped from the occurrence of an abnormality for a time obtained by adding a delay time (the time until the switch circuit 7 functions by a control signal) τ from the detection of an abnormality to the stop of the supply of power. Will take time. In FIG. 2, the power-off behavior of this conventional test apparatus is indicated by a broken line.

  As a result of various studies, it has been found that in the IGBT 2, the drive current and the drive voltage change suddenly due to the occurrence of an abnormality, and an abnormal voltage is generated in the gate voltage due to the influence of this change. Further, it has been found that the abnormality of the gate voltage can be detected in a shorter time than the abnormality detection by the drive current. In such a case, instead of the drive current, the gate voltage is determined based on the determination reference value, and the switch circuit 7 is controlled by the determination signal S1 obtained as a result to cut off the drive power supply (FIG. 2). (C) and (D)), it is possible to cut off the supply of power due to the occurrence of abnormality much more rapidly than in the past.

  That is, in this case, the time τ from the detection of the abnormality until the power is shut off requires the same time as that when the power is shut off based on the drive current I1, but the time until the abnormality is detected may be shortened. As a result, the power can be shut off more quickly than in the past.

  However, in the IGBT 2, in all cases, an abnormal phenomenon does not appear in the gate voltage at a time earlier than the drive current, and there is a case where the abnormality detection by the drive current can cope with the occurrence of the abnormality quickly and reliably. is there.

  Therefore, in this embodiment, the current-voltage conversion resistor 8 is provided in the drive current path, and the drive current of the IGBT 2 is detected by the abnormality detection unit 6 based on the voltage between the terminals of the current-voltage conversion resistor 8. The abnormality detection unit 6 detects the rise of the drive current and detects the abnormality of the IGBT 2 by determining the voltage between the terminals with a predetermined determination reference value. The switch circuit 7 is also controlled based on the determination result to interrupt the supply of drive power. Thus, the present embodiment is configured so as to be able to appropriately cope with various semiconductor element tests.

[Other Embodiments]
As mentioned above, although the specific structure suitable for implementation of this invention was explained in full detail, this invention can change the structure of the above-mentioned embodiment variously in the range which does not deviate from the meaning of this invention.

  That is, in the above-described embodiment, the case of testing the IGBT has been described. However, the present invention is not limited to this, and can be widely applied to the testing of power MOSFETs and the like.

  In the above-described embodiment, the case where the drive current is detected using the current-voltage conversion resistor has been described. However, the present invention is not limited to this, and may be detected by a current probe or the like.

1 Test equipment 2 IGBT
3 Diode 4 Power supply 5 Gate drive unit 6 Abnormality detection unit 7 Switch circuit 8 Current-voltage conversion resistance

Claims (3)

In test equipment for testing semiconductors,
A drive signal output unit for supplying a drive signal to the gate of the semiconductor;
A power supply for supplying driving power to the semiconductor;
A switch circuit that cuts off the supply of the driving power to the semiconductor;
An abnormality detection unit for detecting an abnormality of the semiconductor and driving the switch circuit;
The abnormality detection unit
A test apparatus for detecting an abnormality of the semiconductor based on a gate voltage of the semiconductor. The abnormality detection unit
The test apparatus according to claim 1, wherein an abnormality of the semiconductor is detected based on a gate voltage of the semiconductor by determining the gate voltage of the semiconductor based on a determination reference value. The abnormality detection unit
The test apparatus according to claim 1, further comprising detecting an abnormality of the semiconductor based on a driving current of the semiconductor.

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