Testing device

Abstract

To provide a testing device which automatically switches and can efficiently perform a high voltage test to a plurality of test objects and current voltage characteristic measurement, while avoiding damage of the test object by inattention of an operator and prolongation of a time required for the high voltage test.SOLUTION: A testing device includes a first circuit where a high voltage test is performed, a second circuit where current voltage characteristic measurement is performed, and a control part for controlling the first circuit and the second circuit, wherein the first circuit has a first power source for outputting a first voltage applied to a plurality of test objects in the high voltage test, and a plurality of first switching circuits for electrically connecting or electrically cutting off between the first power source and the plurality of test objects, and the second circuit has a second power source for outputting a second voltage applied to the plurality of test objects in the current voltage characteristic measurement, and a plurality of second switching circuits for electrically connecting or electrically cutting off between the second power source and the plurality of test objects.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a test apparatus. [Background technology]

[0002] In a high-temperature reverse bias test using a power MOSFET or the like as a test object, high temperature and high voltage stress is applied to the test object, and the time until the test object experiences dielectric breakdown is measured.

[0003] Patent Document 1 discloses a withstand voltage test device that applies a high voltage to a plurality of samples simultaneously and controls the applied voltage and application time by detecting the state of each sample with a breakdown detection circuit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 48-84275 Summary of the Invention [Problem to be solved by the invention]

[0005] In the high-temperature reverse bias test according to the background art, in order to measure the degree of deterioration of the test object during the test, it is necessary to interrupt the test, remove the test object from the test tank, and measure the current-voltage characteristics of the test object using a measuring device such as a curve tracer.

[0006] However, when removing the test object from the test chamber, it is necessary to wait until the temperature of the test chamber drops from a high temperature to room temperature. Also, when resuming the high-temperature reverse bias test after measuring the current-voltage characteristics, it is necessary to wait until the temperature of the test chamber rises from room temperature to a high temperature and stabilizes. As a result, unnecessary waiting time is generated and the test time is extended.

[0007] In addition, there is a possibility that the test object may be damaged due to carelessness of the worker when removing the test object from the test chamber or connecting the removed test object to the measuring instrument. Moreover, since high-temperature reverse bias testing often involves simultaneously testing multiple test objects of the same type, performing these tasks manually is extremely inefficient. As a result, the time required for the test is further extended.

[0008] The present invention has been made to solve such problems, and has an object to provide a test device that can automatically switch between high-voltage testing and current-voltage characteristic measurement on a plurality of test objects and efficiently perform the testing while avoiding damage to the test objects due to operator carelessness and prolonging the time required for the high-voltage test. [Means for solving the problem]

[0009] A test apparatus according to a first aspect of the present invention includes a first circuit that performs a high-voltage test on a plurality of test objects, a second circuit that performs a current-voltage characteristics measurement on the plurality of test objects, and a control unit that controls the first circuit and the second circuit, wherein the first circuit includes a first power supply that outputs a first voltage to be applied to the plurality of test objects in the high-voltage test, and a plurality of first switching circuits that electrically connect or disconnect between the first power supply and the plurality of test objects, and the second circuit includes a second power supply that outputs a second voltage to be applied to the plurality of test objects in the current-voltage characteristics measurement, and a plurality of second switching circuits that electrically connect or disconnect between the second power supply and the plurality of test objects, wherein the first circuit and the second circuit include a plurality of channels, each channel corresponding to each of the plurality of test objects, and each of the channels includes a first switching circuit of the plurality of first switching circuits and a second switching circuit of the plurality of second switching circuits.

[0010] According to the first aspect, since the high voltage test can be performed on multiple test objects by the first circuit and the current-voltage characteristics measurement can be performed by the second circuit, the work of removing the test object from the test device for the current-voltage characteristics measurement and the work of connecting the removed test object to a measuring instrument are not required. As a result, it is possible to efficiently perform the high voltage test and the current-voltage characteristics measurement on multiple test objects by automatically switching between them while avoiding damage to the test object due to carelessness of the operator and an increase in the time required for the high voltage test.

[0011] In a test apparatus according to a second aspect of the present invention, in the first aspect, the second circuit may further include a protection circuit connected between the second power supply and the multiple second switching circuits, for protecting the second power supply from the first voltage.

[0012] According to the second aspect, the protection circuit can prevent the second power supply from breaking down due to the first voltage, which is a high voltage, being applied to the second power supply via the test object.

[0013] A third aspect of the present invention is directed to a test apparatus in the first or second aspect, wherein the control unit, when performing the high-voltage test, controls the multiple first switching circuits to electrically connect between the first power source and the multiple test objects, and controls the multiple second switching circuits to electrically disconnect between the second power source and the multiple test objects, and, when performing the current-voltage characteristics measurement, controls the multiple first switching circuits to electrically disconnect between the first power source and the multiple test objects, and controls the multiple second switching circuits to electrically connect between the second power source and the multiple test objects.

[0014] According to the third aspect, by controlling the multiple first switching circuits and the multiple second switching circuits, it is possible to appropriately perform the high voltage test and the current-voltage characteristics measurement, respectively. Also, by controlling the multiple first switching circuits and the multiple second switching circuits, it is possible to appropriately prevent the second power supply from failing due to the high voltage test and the first power supply from failing due to the current-voltage characteristics measurement.

[0015] A fourth aspect of the present invention is a test apparatus in any one of the first to third aspects, wherein the control unit, when performing the high voltage test, controls the first power supply to output the first voltage and controls the second power supply not to output the second voltage, and, when performing the current-voltage characteristics measurement, controls the first power supply not to output the first voltage and controls the second power supply to output the second voltage.

[0016] According to the fourth aspect, by controlling the first power supply and the second power supply, it is possible to more reliably prevent the second power supply from failing due to the execution of a high voltage test, and prevent the first power supply from failing due to the execution of a current-voltage characteristics measurement.

[0017] A fifth aspect of the present invention relates to a test apparatus in the third or fourth aspect, wherein the second power source includes a single second power source common to the multiple channels, and when performing the current-voltage characteristics measurement, the control unit controls the multiple second switching circuits to sequentially electrically connect the multiple test objects to the single second power source.

[0018] According to the fifth aspect, it is necessary to mount only one second power supply, and therefore costs can be reduced.

[0019] A sixth aspect of the present invention relates to a test apparatus according to the third or fourth aspect, wherein the second power source includes a plurality of second power sources, each of the channels further includes each of the second power sources of the plurality of second power sources, and the control unit, when performing the current-voltage characteristics measurement, controls the plurality of second switching circuits to electrically connect the plurality of second power sources and the plurality of test objects in parallel.

[0020] According to the sixth aspect, since the current-voltage characteristics measurements can be performed on a plurality of test objects in parallel, the time required for the current-voltage characteristics measurements can be shortened.

[0021] A seventh aspect of the present invention is a test apparatus according to any one of the first to sixth aspects, wherein each of the test objects has a control electrode, the first circuit further includes a third power supply that outputs a third voltage to be applied to each of the control electrodes of the multiple test objects in the high voltage test, and a plurality of third switching circuits that electrically connect or disconnect between the third power supply and each of the control electrodes of the multiple test objects, the second circuit further includes a fourth power supply that outputs a fourth voltage to be applied to each of the control electrodes of the multiple test objects in the current-voltage characteristics measurement, and a plurality of fourth switching circuits that electrically connect or disconnect between the fourth power supply and each of the control electrodes of the multiple test objects, and each of the channels further includes a third switching circuit of the plurality of third switching circuits, and a fourth switching circuit of the plurality of fourth switching circuits.

[0022] According to the seventh aspect, a semiconductor element having a control electrode such as a power transistor can be used as the test object. Also, by controlling the third switching circuits and the fourth switching circuits, it is possible to appropriately prevent the fourth power supply from failing due to the high voltage test and the third power supply from failing due to the current-voltage characteristics measurement.

[0023] An eighth aspect of the present invention is a test apparatus according to the seventh aspect, wherein the third power supply includes a plurality of third power supplies, each of the channels further includes each of the third power supplies of the plurality of third power supplies, and the control unit, when performing the high voltage test, controls the plurality of third switching circuits to electrically connect the plurality of third power supplies and each of the control electrodes of the plurality of test objects in parallel.

[0024] According to the eighth aspect, since the high voltage test can be performed on multiple test objects in parallel, the time required for the high voltage test can be shortened. Also, since each channel includes the third power supply, even if the test object of one channel experiences a dielectric breakdown, the desired voltage can be reliably applied from the third power supply to the control electrode of the test object of the other channel.

[0025] A ninth aspect of the present invention is a test apparatus according to the seventh or eighth aspect, wherein the fourth power supply includes one fourth power supply common to the multiple channels, and when performing the current-voltage characteristics measurement, the control unit controls the multiple fourth switching circuits to electrically connect each of the control electrodes of the multiple test objects in sequence to the one fourth power supply.

[0026] According to the ninth aspect, it is necessary to mount only one fourth power supply, and therefore costs can be reduced.

[0027] A tenth aspect of the present invention is directed to a test apparatus according to the seventh or eighth aspect, wherein the fourth power supply includes a plurality of fourth power supplies, each of the channels further includes each of the fourth power supplies of the plurality of fourth power supplies, and the control unit, when performing the current-voltage characteristics measurement, controls the plurality of fourth switching circuits to electrically connect the plurality of fourth power supplies and each of the control electrodes of the plurality of test objects in parallel.

[0028] According to the tenth aspect, since the current-voltage characteristics measurements can be performed on a plurality of test objects in parallel, the time required for the current-voltage characteristics measurements can be shortened.

[0029] The testing apparatus according to an eleventh aspect of the present invention is any one of the first to tenth aspects, and preferably further comprises a test chamber having an internal space in which the plurality of test objects are placed and controlling an environment of the internal space.

[0030] According to the eleventh aspect, by placing the test object in the test tank, it is possible to apply environmental stress such as temperature stress to the test object. As a result, it becomes possible to carry out a high-temperature reverse bias test or the like on a power transistor or the like as the test object. Effect of the Invention

[0031] According to the present invention, it is possible to automatically switch between high-voltage testing and current-voltage characteristic measurement on a plurality of test objects and efficiently perform the testing while avoiding damage to the test objects due to carelessness on the part of the operator and an increase in the time required for the high-voltage testing. [Brief description of the drawings]

[0032] [Figure 1] 1 is a diagram showing a simplified configuration of a test device according to an embodiment of the present invention; [Diagram 2] 1 is a diagram showing a simplified configuration of a test device according to an embodiment of the present invention; [Diagram 3] 1 is a diagram showing a simplified configuration of a test device according to an embodiment of the present invention; [Figure 4] 1 is a diagram showing a simplified configuration of a test device according to an embodiment of the present invention; [Diagram 5] 4 is a timing chart showing the relationship between the timing of performing a high voltage test or a current-voltage characteristic measurement and the temperature control of the internal space of a test chamber. [Figure 6] FIG. 13 is a diagram showing a simplified configuration of a test device according to a modified example. [Figure 7] FIG. 13 is a diagram showing a simplified configuration of a test device according to another modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In addition, elements with the same reference numerals in different drawings indicate the same or corresponding elements.

[0034] 1 to 4 are diagrams showing a simplified configuration of a test apparatus according to an embodiment of the present invention. The test apparatus includes a first circuit 1 that performs a high-voltage test on test objects SA and SB, a second circuit 2 that performs a current-voltage characteristic measurement on the test objects SA and SB, and a control unit 3 that controls the first circuit 1 and the second circuit 2.

[0035] The control unit 3 is a microcontroller, a programmable logic controller, a general-purpose personal computer, or the like.

[0036] In the example of this embodiment, for the sake of simplicity, only two test objects SA and SB are shown, but the number of test objects SA and SB may be three or more.

[0037] The test objects SA and SB are, for example, semiconductor elements of the same type. The semiconductor elements may be three-electrode power transistors such as power MOSFETs, bipolar transistors, or IGBTs. In the example of this embodiment, the test objects SA and SB are N-channel power MOSFETs having three electrodes: gate G, source S, and drain D. The semiconductor elements may also be three-electrode thyristors. The semiconductor elements may also be two-electrode high-voltage diodes. The test objects SA and SB are not limited to semiconductor elements, and may also be paint for in-vehicle devices with insulating paint applied to a metal surface, ceramic joints, etc.

[0038] The high voltage test performed by the first circuit 1 is a test for evaluating the durability or performance of the test objects SA, SB by applying a high voltage to the test objects SA, SB. The high voltage test includes a high temperature reverse bias test or a withstand voltage test. For example, in a high temperature reverse bias test, the stress of high temperature and high voltage is applied to the test objects SA, SB for a long period of time, and the time until the test objects SA, SB are destroyed is measured and recorded.

[0039] The current-voltage characteristic measurements performed by the second circuit 2 include threshold voltage measurements, on-resistance measurements, and breakdown voltage measurements, etc., for measuring the degree of degradation of the test objects SA and SB during the high-voltage test. In threshold voltage measurements, the threshold voltage is measured by sweeping the gate voltage while fixing the drain voltage to a constant value and measuring the drain current. In on-resistance measurements, the on-resistance is measured by sweeping the drain current while fixing the gate voltage to a constant on-voltage value and measuring the drain voltage. In breakdown voltage measurements, the breakdown voltage is measured by sweeping the drain voltage while fixing the gate voltage to a constant off-voltage value and measuring the drain current.

[0040] As shown in FIG. 4, the test apparatus includes a test chamber 80. The test chamber 80 has an internal space in which a plurality of test objects including test objects SA and SB are placed. The plurality of test objects are, for example, fixed to a jig (not shown) and housed in the internal space of the test chamber 80 with the jig attached to a rack (not shown). The control unit 3 controls the temperature of the internal space of the test chamber 80 by a heater 90 arranged in the test chamber 80. The heater 90 can control the temperature of the internal space of the test chamber 80 to a high temperature of, for example, about 200 to 300° C. In addition to the heater 90, a cooler for cooling may be arranged in the internal space of the test chamber 80. Also, by arranging a humidifier and a dehumidifier in the internal space of the test chamber 80, humidity as well as temperature may be controlled.

[0041] As shown in FIGS. 1 to 3, the first circuit 1 has a first power supply 11 and first switching circuits 21A, 21B. The first power supply 11 outputs a first voltage V1, which is a high voltage to be applied to the drains D of the test objects SA, SB in a high voltage test. The first switching circuit 21A electrically connects or disconnects the positive electrode of the first power supply 11 and the drain D of the test object SA, and the first switching circuit 21B electrically connects or disconnects the positive electrode of the first power supply 11 and the drain D of the test object SB. The first switching circuits 21A, 21B are configured using mechanical relays, semiconductor relays, or the like.

[0042] The second circuit 2 has a second power supply 12 and second switching circuits 22A, 22B. The second power supply 12 outputs a second voltage V2 to be applied to the drains D of the test objects SA, SB in current-voltage characteristic measurement. The second switching circuit 22A electrically connects or disconnects the positive electrode of the second power supply 12 and the drain D of the test object SA, and the second switching circuit 22B electrically connects or disconnects the positive electrode of the second power supply 12 and the drain D of the test object SB. The second switching circuits 22A, 22B are configured using mechanical relays, semiconductor relays, or the like.

[0043] The first circuit 1 also includes third power sources 13A and 13B and third switching circuits 23A and 23B. The third power source 13A outputs a third voltage V3 to be applied to the gate G of the test object SA in the high voltage test, and the third power source 13B outputs a third voltage V3 to be applied to the gate G of the test object SB in the high voltage test. The third switching circuit 23A electrically connects or disconnects the negative electrode of the third power source 13A and the gate G of the test object SA, and the third switching circuit 23B electrically connects or disconnects the negative electrode of the third power source 13B and the gate G of the test object SB. The third switching circuits 23A and 23B are configured using mechanical relays, semiconductor relays, or the like.

[0044] The second circuit 2 also has a fourth power supply 14 and fourth switching circuits 24A, 24B. The fourth power supply 14 outputs a fourth voltage V4 to be applied to the gates G of the test objects SA, SB in current-voltage characteristic measurement. The fourth switching circuit 24A electrically connects or disconnects the positive electrode of the fourth power supply 14 and the gate G of the test object SA, and the fourth switching circuit 24B electrically connects or disconnects the positive electrode of the fourth power supply 14 and the gate G of the test object SB. The fourth switching circuits 24A, 24B are configured using mechanical relays, semiconductor relays, or the like.

[0045] The first circuit 1 has ammeters 41A, 41B, 43A, and 43B, and the second circuit 2 has an ammeter 44. The ammeter 41A is connected between the first power source 11 and the first switching circuit 21A. The ammeter 41B is connected between the first power source 11 and the first switching circuit 21B. The ammeter 43A is connected between the third power source 13A and the third switching circuit 23A. The ammeter 43B is connected between the third power source 13B and the third switching circuit 23B. The ammeter 44 is connected between the fourth power source 14 and the fourth switching circuits 24A and 24B.

[0046] The second circuit 2 also has protection circuits 31A and 31B. The protection circuit 31A is connected between the gate G of the test object SA and the third switching circuit 23A and the fourth switching circuit 24A. The protection circuit 31B is connected between the gate G of the test object SB and the third switching circuit 23B and the fourth switching circuit 24B.

[0047] The second circuit 2 includes fifth switching circuits 25A and 25B, sixth switching circuits 26A and 26B, protection circuits 32 and 33, an ammeter 42, and a voltmeter 51. The fifth switching circuit 25A is connected between the drain D of the test object SA and the protection circuit 33, and the fifth switching circuit 25B is connected between the drain D of the test object SB and the protection circuit 33. The sixth switching circuit 26A is connected between the source S of the test object SA and the voltmeter 51, and the sixth switching circuit 26B is connected between the source S of the test object SB and the voltmeter 51. The protection circuit 32 is connected between the second switching circuit 22A and the ammeter 42, and the protection circuit 33 is connected between the fifth switching circuits 25A and 25B and the voltmeter 51. The ammeter 42 is connected between the protection circuit 32 and the positive electrode of the second power source 12. The voltmeter 51 is connected between the protection circuit 33 and the sixth switching circuits 26A, 26B. The fifth switching circuits 25A, 25B and the sixth switching circuits 26A, 26B are configured using mechanical relays, semiconductor relays, or the like.

[0048] The protection circuits 31A, 31B, 32, and 33 have an overcurrent limiting function and an overvoltage limiting function, and protect the circuit elements from sudden surge currents and surge voltages. The protection circuit 32 protects the second power supply 12 and the ammeter 42 from surge currents and surge voltages caused by the high first voltage V1, and the protection circuit 33 protects the voltmeter 51 from surge currents and surge voltages caused by the high first voltage V1. The protection circuit 31A protects the fourth power supply 14 and the ammeter 44 from surge currents and surge voltages caused by the first voltage V1, and protects the third power supply 13A and the ammeter 43A from surge currents and surge voltages caused by the second voltage V2. The protection circuit 31B protects the fourth power supply 14 and the ammeter 44 from surge currents and surge voltages caused by the first voltage V1, and protects the third power supply 13B and the ammeter 43B from surge currents and surge voltages caused by the second voltage V2.

[0049] The test device is connected to the test objects SA and SB and has a plurality of channels CH for performing a high voltage test and a current-voltage characteristic measurement on the test objects SA and SB. Specifically, the first circuit 1 and the second circuit 2 have a plurality of channels CHA and CHB, each of which corresponds to one of the test objects SA and SB.

[0050] The channel CHA corresponding to the test object SA includes the first switching circuit 21A, the second switching circuit 22A, the third switching circuit 23A, the fourth switching circuit 24A, the fifth switching circuit 25A, the sixth switching circuit 26A, the ammeters 41A and 43A, the protection circuit 31A, and the third power supply 13A. The channel CHB corresponding to the test object SB includes the first switching circuit 21B, the second switching circuit 22B, the third switching circuit 23B, the fourth switching circuit 24B, the fifth switching circuit 25B, the sixth switching circuit 26B, the ammeters 41B and 43B, the protection circuit 31B, and the third power supply 13B.

[0051] The control unit 3 controls the first power source 11, the second power source 12, the third power source 13A, 13B, the fourth power source 14, the first switching circuits 21A, 21B, the second switching circuits 22A, 22B, the third switching circuits 23A, 23B, the fourth switching circuits 24A, 24B, the fifth switching circuits 25A, 25B, and the sixth switching circuits 26A, 26B.

[0052] Figure 1 shows an example of control when performing a high voltage test on test objects SA and SB, Figure 2 shows an example of control when performing a current-voltage characteristic measurement on test object SA, and Figure 3 shows an example of control when performing a current-voltage characteristic measurement on test object SB.

[0053] As shown in FIG. 1, when performing a high voltage test on test objects SA and SB, the control unit 3 turns on the first power supply 11, turns off the second power supply 12, turns on the third power supplies 13A and 13B, turns off the fourth power supply 14, turns on the first switching circuits 21A and 21B, turns off the second switching circuits 22A and 22B, turns on the third switching circuits 23A and 23B, turns off the fourth switching circuits 24A and 24B, turns off the fifth switching circuits 25A and 25B, and turns off the sixth switching circuits 26A and 26B.

[0054] As a result, the first power supply 11 outputs the first voltage V1, the second power supply 12 does not output the second voltage V2, the third power supplies 13A and 13B output the third voltage V3, and the fourth power supply 14 does not output the fourth voltage V4. In addition, the first switching circuits 21A and 21B are in an electrically connected state, the second switching circuits 22A and 22B are in an electrically cut-off state, the third switching circuits 23A and 23B are in an electrically connected state, the fourth switching circuits 24A and 24B are in an electrically cut-off state, the fifth switching circuits 25A and 25B are in an electrically cut-off state, and the sixth switching circuits 26A and 26B are in an electrically cut-off state.

[0055] A high voltage test is carried out on the test objects SA and SB by applying a high first voltage V1 to the drain D while the gate G is reverse-biased by the third voltage V3.

[0056] As shown in FIG. 2, when performing a current-voltage characteristic measurement on the test object SA, the control unit 3 turns off the first power supply 11, turns on the second power supply 12, turns off the third power supplies 13A and 13B, turns on the fourth power supply 14, turns off the first switching circuits 21A and 21B, turns on the second switching circuit 22A, turns off the second switching circuit 22B, turns off the third switching circuits 23A and 23B, turns on the fourth switching circuit 24A, turns off the fourth switching circuit 24B, turns on the fifth switching circuit 25A, turns off the fifth switching circuit 25B, turns on the sixth switching circuit 26A, and turns off the sixth switching circuit 26B.

[0057] As a result, the first power supply 11 does not output the first voltage V1, the second power supply 12 outputs the second voltage V2, the third power supplies 13A and 13B do not output the third voltage V3, and the fourth power supply 14 outputs the fourth voltage V4. Also, the first switching circuits 21A and 21B are in an electrically disconnected state, the second switching circuit 22A is in an electrically connected state, the second switching circuit 22B is in an electrically disconnected state, the third switching circuits 23A and 23B are in an electrically disconnected state, the fourth switching circuit 24A is in an electrically connected state, the fourth switching circuit 24B is in an electrically disconnected state, the fifth switching circuit 25A is in an electrically connected state, the fifth switching circuit 25B is in an electrically disconnected state, the sixth switching circuit 26A is in an electrically connected state, and the sixth switching circuit 26B is in an electrically disconnected state.

[0058] For example, in threshold voltage measurement, a constant voltage is applied to the drain D of the test object SA using the second voltage V2, while the voltage of the gate G of the test object SA is swept using the fourth voltage V4, and the current of the drain D of the test object SA is measured using the ammeter 42, thereby measuring the threshold voltage of the test object SA.

[0059] The sixth switching circuit 26B is turned off in order to turn off three of the four terminals of the test object SB in the four-terminal method when switching to the test object SA. The path including the voltmeter 51 has a smaller current value than the path including the second power source 12. Therefore, by arranging the sixth switching circuit 26B in the path including the voltmeter 51, the degree of freedom in selecting elements for the sixth switching circuit 26B is increased compared to the case where the sixth switching circuit 26B is arranged in the path including the second power source 12.

[0060] As shown in FIG. 3, when performing a current-voltage characteristic measurement on the test object SB, the control unit 3 turns off the first power supply 11, turns on the second power supply 12, turns off the third power supplies 13A and 13B, turns on the fourth power supply 14, turns off the first switching circuits 21A and 21B, turns off the second switching circuit 22A, turns on the second switching circuit 22B, turns off the third switching circuits 23A and 23B, turns off the fourth switching circuit 24A, turns on the fourth switching circuit 24B, turns off the fifth switching circuit 25A, turns on the fifth switching circuit 25B, turns off the sixth switching circuit 26A, and turns on the sixth switching circuit 26B.

[0061] As a result, the first power supply 11 does not output the first voltage V1, the second power supply 12 outputs the second voltage V2, the third power supplies 13A and 13B do not output the third voltage V3, and the fourth power supply 14 outputs the fourth voltage V4. Also, the first switching circuits 21A and 21B are in an electrically disconnected state, the second switching circuit 22A is in an electrically disconnected state, the second switching circuit 22B is in an electrically connected state, the third switching circuits 23A and 23B are in an electrically disconnected state, the fourth switching circuit 24A is in an electrically disconnected state, the fourth switching circuit 24B is in an electrically connected state, the fifth switching circuit 25A is in an electrically disconnected state, the fifth switching circuit 25B is in an electrically connected state, the sixth switching circuit 26A is in an electrically disconnected state, and the sixth switching circuit 26B is in an electrically connected state.

[0062] For example, in threshold voltage measurement, a constant voltage is applied to the drain D of the test object SB using the second voltage V2, while the voltage of the gate G of the test object SB is swept using the fourth voltage V4, and the current of the drain D of the test object SB is measured using the ammeter 42, thereby measuring the threshold voltage of the test object SB.

[0063] The sixth switching circuit 26A is turned off in order to turn off three of the four terminals of the test object SA in the four-terminal method when switching to the test object SB. The path including the voltmeter 51 has a smaller current value than the path including the second power source 12. Therefore, by arranging the sixth switching circuit 26A in the path including the voltmeter 51, the degree of freedom in selecting elements for the sixth switching circuit 26A is increased compared to the case where the sixth switching circuit 26A is arranged in the path including the second power source 12.

[0064] FIG. 5 is a timing chart showing the relationship between the timing of performing a high voltage test or a current-voltage characteristic measurement and the temperature control of the internal space of the test chamber 80. As shown in FIG.

[0065] At time T0, the control unit 3 performs a first current-voltage characteristic measurement X0. At time T0, the temperature of the internal space of the test tank 80 is room temperature K0. In the current-voltage characteristic measurement X0, the control unit 3 performs current-voltage characteristic measurements on the test objects SA and SB in order.

[0066] At time T1, the control unit 3 causes the heater 90 to start increasing the temperature of the internal space of the test chamber 80.

[0067] At time T2, the temperature of the internal space of the test chamber 80 rises to the target temperature K1.

[0068] At time T3, when a predetermined time has elapsed since time T2 and the temperature of the internal space of the test chamber 80 stabilizes at the target temperature K1, the control unit 3 causes the first power supply 11 to start increasing the output voltage.

[0069] At time T4, when the output voltage of the first power supply 11 rises to the first voltage V1, the control unit 3 starts to carry out a high voltage test and starts integrating the test time.

[0070] When the timing for measuring the current-voltage characteristics arrives, at time T5, the control unit 3 turns off the first power supply 11 and stops accumulating the test time of the high voltage test. The control unit 3 saves an accumulated value P1 of the test time from time T4 to time T5. The timing for measuring the current-voltage characteristics may be a fixed time interval, or may be a time interval that varies depending on the degree of deterioration of the test objects SA and SB.

[0071] At time T6, the control unit 3 performs a second current-voltage characteristic measurement X1. At time T6, the temperature of the internal space of the test tank 80 is maintained at the target temperature K1. In the current-voltage characteristic measurement X1, the control unit 3 performs current-voltage characteristic measurements on the test objects SA and SB in turn.

[0072] When the second current-voltage characteristic measurement X1 is completed, at time T7, the control unit 3 causes the first power supply 11 to start increasing the output voltage again.

[0073] At time T8, when the output voltage of the first power supply 11 rises again to the first voltage V1, the control unit 3 restarts integrating the test time of the high voltage test.

[0074] When the next timing for measuring the current-voltage characteristics arrives, at time T9, the control unit 3 turns off the first power supply 11 and stops integrating the test time of the high voltage test. The control unit 3 stores an integrated value P2 of the test time from time T8 to time T9.

[0075] At time T10, the control unit 3 performs a third current-voltage characteristics measurement X2. At time T10, the temperature of the internal space of the test tank 80 is maintained at the target temperature K1. In the current-voltage characteristics measurement X10, the control unit 3 performs current-voltage characteristics measurements on the test objects SA and SB in turn.

[0076] The control unit 3 repeatedly executes the same process as above until the sum of the integrated values ​​P1, P2, . . . , Pn of the test time of the high voltage test becomes the target test time.

[0077] At time T14, the control unit 3 stops driving the heater 90, thereby causing the temperature in the internal space of the test chamber 80 to start decreasing.

[0078] At time T15, the temperature of the internal space of the test chamber 80 drops to room temperature K0.

[0079] At time T16, when a predetermined waiting time has elapsed since time T15, the control unit 3 performs the final current-voltage characteristics measurement Xn+1. In the current-voltage characteristics measurement Xn+1, the control unit 3 performs current-voltage characteristics measurements on the test objects SA and SB in order.

[0080] It should be noted that the timing chart shown in Fig. 5 is merely an example, and the timing for measuring the current-voltage characteristics is not limited to the example shown in Fig. 5. For example, the timing for measuring the current-voltage characteristics may be added between time T2 and time T3.

[0081] According to the test device of this embodiment, a high voltage test can be performed on multiple test objects SA, SB by the first circuit 1, and a current-voltage characteristic measurement can be performed by the second circuit 2, eliminating the need to remove the test objects SA, SB from the test device for the current-voltage characteristic measurement and to connect the removed test objects SA, SB to a measuring instrument. As a result, it becomes possible to efficiently perform high voltage tests and current-voltage characteristic measurements on multiple test objects SA, SB by automatically switching between them, while avoiding damage to the test objects SA, SB due to carelessness on the part of the operator and an increase in the time required for the high voltage test.

[0082] Furthermore, according to the test apparatus of this embodiment, the protection circuit 32 can prevent the second power supply 12 from breaking down due to the high first voltage V1 being applied to the second power supply 12 via the test objects SA and SB.

[0083] Moreover, according to the test device of this embodiment, the high voltage test and the current-voltage characteristics measurement can be appropriately performed by controlling the multiple first switching circuits 21A, 21B and the multiple second switching circuits 22A, 22B. Moreover, by controlling the multiple first switching circuits 21A, 21B and the multiple second switching circuits 22A, 22B, it is possible to appropriately prevent the second power supply 12 from breaking down due to the high voltage test and the first power supply 11 from breaking down due to the current-voltage characteristics measurement.

[0084] Furthermore, according to the test apparatus of this embodiment, by controlling the first power supply 11 and the second power supply 12, it is possible to more reliably prevent the second power supply 12 from breaking down due to the execution of a high voltage test, and prevent the first power supply 11 from breaking down due to the execution of a current-voltage characteristics measurement.

[0085] Furthermore, according to the test device of this embodiment, when current-voltage characteristics measurement is performed, the control unit 3 controls the multiple second switching circuits 22A, 22B to sequentially electrically connect the multiple test objects SA, SB to the single second power source 12. This makes it necessary to implement only the single second power source 12, thereby reducing costs.

[0086] Moreover, according to the test device of this embodiment, semiconductor elements having gates G (control electrodes) such as power transistors can be used as test objects SA and SB. Moreover, by controlling the plurality of third switching circuits 23A and 23B and the plurality of fourth switching circuits 24A and 24B, it is possible to appropriately prevent the fourth power supply 14 from breaking down due to the implementation of a high voltage test, and the third power supplies 13A and 13B from breaking down due to the implementation of current-voltage characteristic measurements.

[0087] According to the test device of this embodiment, when a high voltage test is performed, the control unit 3 controls the multiple third switching circuits 23A, 23B to electrically connect the multiple third power sources 13A, 13B to the gates G of the multiple test objects SA, SB simultaneously in parallel. This allows the high voltage test to be performed simultaneously on the multiple test objects SA, SB, thereby shortening the time required for the high voltage test. Furthermore, since each channel CH includes the third power sources 13A, 13B, even if the test object SA of a certain channel CHA causes a dielectric breakdown, the desired voltage can be reliably applied from the third power source 13B to the gate G of the test object SB of the other channel CHB.

[0088] Furthermore, according to the test device of this embodiment, when current-voltage characteristics measurement is performed, the control unit 3 controls the multiple fourth switching circuits 24A, 24B to sequentially electrically connect each gate G of the multiple test objects SA, SB to the single fourth power supply 14. This makes it necessary to implement only the single fourth power supply 14, thereby reducing costs.

[0089] Furthermore, according to the test apparatus of this embodiment, it is possible to apply environmental stress such as temperature stress to the test objects SA and SB by placing the test objects SA and SB in the test tank 80. As a result, it is possible to carry out a high-temperature reverse bias test or the like on the test objects SA and SB, such as power transistors.

[0090] <Modification> 6 is a simplified diagram showing the configuration of a test apparatus according to a modified example. In this modified example, the test objects SA and SB are high-voltage diodes having two electrodes, an anode A and a cathode K. When performing a high-voltage test on the test objects SA and SB, the control unit 3 turns on the first power supply 11, turns off the second power supply 12, turns on the first switching circuits 21A and 21B, turns off the second switching circuits 22A and 22B, turns off the fifth switching circuits 25A and 25B, and turns off the sixth switching circuits 26A and 26B. When performing current-voltage characteristic measurement on the test object SA, the control unit 3 turns off the first power supply 11, turns on the second power supply 12, turns off the first switching circuits 21A and 21B, turns on the second switching circuit 22A, turns off the second switching circuit 22B, turns on the fifth switching circuit 25A, turns off the fifth switching circuit 25B, turns on the sixth switching circuit 26A, and turns off the sixth switching circuit 26B. When performing current-voltage characteristic measurement on the test object SB, the control unit 3 turns off the first power supply 11, turns on the second power supply 12, turns off the first switching circuits 21A and 21B, turns off the second switching circuit 22A, turns on the second switching circuit 22B, turns off the fifth switching circuit 25A, turns on the fifth switching circuit 25B, turns off the sixth switching circuit 26A, and turns on the sixth switching circuit 26B. In this way, even for test objects SA and SB having two electrodes, it is possible to switch between high voltage testing and current-voltage characteristic measurement. The same is true for the case of three or more channels.

[0091] Fig. 7 is a diagram showing a simplified configuration of a test device according to another modified example. In the above embodiment, each test object SA, SB is connected to the ammeter 42 and the voltmeter 51 by the four-terminal method, but this is not limited to the example. As shown in Fig. 7, the protection circuit 32 and the second switching circuits 22A, 22B may be omitted from the configuration of the embodiment, and the ammeter 42 and the second power source 12 may be connected between the protection circuit 33 and the sixth switching circuits 26A, 26B, so that each test object SA, SB is connected to the ammeter 42 and the voltmeter 51 by the two-terminal method.

[0092] In the above embodiment, only one second power source 12 common to the two channels CHA and CHB is implemented, but two second power sources 12 may be implemented corresponding to the two channels CHA and CHB. In this case, each channel CHA and CHB includes an independent second power source 12, and when performing current-voltage characteristic measurement, the control unit 3 controls the multiple second switching circuits 22A and 22B to electrically connect the multiple second power sources 12 and the multiple test objects SA and SB simultaneously in parallel. This allows current-voltage characteristic measurement to be performed simultaneously on the multiple test objects SA and SB, thereby shortening the time required for the current-voltage characteristic measurement. The same applies to the case of three or more channels.

[0093] Similarly, in the above embodiment, only one fourth power supply 14 common to the two channels CHA and CHB is implemented, but two fourth power supplies 14 corresponding to the two channels CHA and CHB may be implemented. In this case, each channel CHA and CHB includes an independent fourth power supply 14, and the control unit 3 controls the multiple fourth switching circuits 24A and 24B to electrically connect the multiple fourth power supplies 14 and the multiple test objects SA and SB simultaneously in parallel when performing current-voltage characteristic measurement. This allows current-voltage characteristic measurement to be performed simultaneously on the multiple test objects SA and SB, thereby shortening the time required for current-voltage characteristic measurement. The same applies to the case of three or more channels.

[0094] In the above embodiment, for example, when a high-voltage test is performed on the test subject SA, the first power supply 11 and the first switching circuit 21A are turned on and the second power supply 12 and the second switching circuit 22A are turned off, and when a current-voltage characteristic measurement is performed on the test subject SA, the first power supply 11 and the first switching circuit 21A are turned off and the second power supply 12 and the second switching circuit 22A are turned on. As a first modified example, when a high-voltage test is performed, the first power supply 11 and the first switching circuit 21A are turned on, the second power supply 12 is turned off, and the second switching circuit 22A is turned on, and when a current-voltage characteristic measurement is performed, the first power supply 11 may be turned off, the first switching circuit 21A is turned on, and the second power supply 12 and the second switching circuit 22A are turned on. As a second modification, when a high voltage test is performed, the first power supply 11 and the first switching circuit 21A may be turned on, the second power supply 12 may be turned off, and the second switching circuit 22A may be turned on, and when a current-voltage characteristic measurement is performed, the first power supply 11 and the first switching circuit 21A may be turned off, and the second power supply 12 and the second switching circuit 22A may be turned on. As a third modification, when a high voltage test is performed, the first power supply 11 and the first switching circuit 21A may be turned on, and the second power supply 12 and the second switching circuit 22A may be turned off, and when a current-voltage characteristic measurement is performed, the first power supply 11 may be turned off, the first switching circuit 21A may be turned on, and the second power supply 12 and the second switching circuit 22A may be turned on. The same applies to other test objects SB, etc. [Explanation of symbols]

[0095] 1 1st circuit 2 2nd circuit 3. Control Unit 11 1st power supply 12 2nd power supply 13A,13B 3rd power supply 14 4th power supply 21A, 21B First switching circuit 22A, 22B Second switching circuit 23A, 23B Third switching circuit 24A, 24B 4th switching circuit 32 Protection circuit 80 Test Tank

Claims

1. a first circuit for performing high voltage testing on a plurality of test objects; a second circuit for performing current-voltage characteristic measurements on the plurality of test objects; A control unit that controls the first circuit and the second circuit; Equipped with The first circuit is a first power supply that outputs a first voltage to be applied to the plurality of test objects in the high voltage test; a plurality of first switching circuits that electrically connect or disconnect the first power source and the plurality of test objects; having The second circuit is a second power supply that outputs a second voltage to be applied to the plurality of test objects in the current-voltage characteristic measurement; a plurality of second switching circuits that electrically connect or disconnect the second power source and the plurality of test objects; having the first circuit and the second circuit have a plurality of channels, each channel corresponding to a respective test object of the plurality of test objects; Each of the channels includes a first switching circuit of the plurality of first switching circuits and a second switching circuit of the plurality of second switching circuits.

2. 2. The test apparatus according to claim 1, wherein the second circuit further comprises a protection circuit connected between the second power supply and the plurality of second switching circuits, the protection circuit protecting the second power supply from the first voltage.

3. The control unit is When carrying out the high voltage test, controlling the plurality of first switching circuits to electrically connect between the first power source and the plurality of devices under test; controlling the second switching circuits to electrically isolate the second power source from the plurality of test objects; When the current-voltage characteristic measurement is performed, controlling the plurality of first switching circuits to electrically cut off between the first power source and the plurality of test objects; The test apparatus according to claim 1 , further comprising: a second switching circuit configured to electrically connect the second power supply to the plurality of devices under test.

4. The control unit is When carrying out the high voltage test, controlling the first power supply to output the first voltage; controlling the second power supply so as not to output the second voltage; When the current-voltage characteristic measurement is performed, controlling the first power supply so as not to output the first voltage; The test apparatus according to claim 1 , further comprising: a second power supply configured to output the second voltage.

5. the second power source includes one second power source common to the plurality of channels; 4. The test apparatus according to claim 3, wherein the control unit controls the second switching circuits to sequentially electrically connect the plurality of test devices to the one second power source when the current-voltage characteristics measurement is performed.

6. the second power source includes a plurality of second power sources; each of the channels further includes a respective second power source of the plurality of second power sources; 4. The test apparatus according to claim 3, wherein the control unit controls the second switching circuits to electrically connect the second power sources and the test objects in parallel when performing the current-voltage characteristics measurement.

7. Each of the test objects has a control electrode; The first circuit is a third power supply that outputs a third voltage to be applied to each of the control electrodes of the plurality of test objects in the high voltage test; a plurality of third switching circuits that electrically connect or disconnect the third power source and each of the control electrodes of the plurality of test objects; and The second circuit is a fourth power supply that outputs a fourth voltage to be applied to each of the control electrodes of the plurality of test objects in the current-voltage characteristic measurement; a plurality of fourth switching circuits that electrically connect or disconnect the fourth power source and each of the control electrodes of the plurality of test objects; and 2. The test apparatus according to claim 1, wherein each of the channels further includes a third switching circuit of the plurality of third switching circuits and a fourth switching circuit of the plurality of fourth switching circuits.

8. the third power source includes a plurality of third power sources; each of the channels further includes a third power source of the plurality of third power sources; 8. The test apparatus according to claim 7, wherein the control unit controls the third switching circuits to electrically connect the third power sources and the control electrodes of the test objects in parallel when the high voltage test is performed.

9. the fourth power source includes one fourth power source common to the plurality of channels; 8. The test apparatus according to claim 7, wherein the control unit controls the plurality of fourth switching circuits to sequentially electrically connect each of the control electrodes of the plurality of test objects to the one fourth power source when the current-voltage characteristics measurement is performed.

10. the fourth power source includes a plurality of fourth power sources; each of the channels further includes a fourth power source of the plurality of fourth power sources; 8. The test apparatus according to claim 7, wherein the control unit controls the plurality of fourth switching circuits to electrically connect the plurality of fourth power sources and each of the control electrodes of the plurality of test objects in parallel when performing the current-voltage characteristics measurement.

11. 11. The testing apparatus according to claim 1, further comprising a test chamber having an internal space in which the plurality of test objects are placed and controlling an environment of the internal space.

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