Switch module inspection apparatus and switching element inspection method

Abstract

To provide a switch module inspection apparatus not requiring replacement of an inspection voltage switching relay, and a switching element inspection method.SOLUTION: A switch module inspection apparatus 1 comprises: a first voltage detection part 2, a second voltage detection part 3 and a current detection part 4 detecting a voltage and / or a current of output terminals or input terminals of a plurality of semiconductor switches T; a connection part 8 obtained by configuring a series circuit by series connecting a first element which one of the plurality of semiconductor switches T and a second element which is different from the first element and one of the plurality of semiconductor switches T with a coil interposed therebetween; a power supply unit 5 outputting an inspection voltage to the series circuit; and an inspection processing part 6 supplying the inspection voltage to the first element through the coil by turning on the second element, and performing inspection processing for inspecting the first element during a voltage supply period in which the inspection voltage is supplied to the first element, on the basis of a detection value of the voltage and / or current detected by the detection part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a switch module inspection device for inspecting a switch module including a plurality of semiconductor switching elements, and a switching element inspection method. [Background technology]

[0002] Conventionally, there has been known a power semiconductor testing device that has a high-voltage power supply, an inductive load that serves as a load for a power semiconductor under test that is connected to the high-voltage power supply, a mechanical relay that connects the inductive load to the positive side, and a mechanical relay that connects the inductive load to the negative side, and that evaluates switching characteristics by turning on the mechanical relay to apply a voltage to the power semiconductor and performing double pulse driving of the power semiconductor (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-160572 (paragraphs 0016, 0020, Figure 1) Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned technology uses a mechanical relay that switches a high-voltage inspection voltage to inspect high-capacity power semiconductors, and therefore the relay must be periodically replaced due to the end of its life.

[0005] An object of the present invention is to provide a switch module inspection device and a switching element inspection method that do not require replacement of relays for switching an inspection voltage. [Means for solving the problem]

[0006] A switch module inspection device according to one embodiment of the present invention is a switch module inspection device that inspects a switch module having a plurality of semiconductor switching elements, and includes a detection unit that detects a voltage and / or a current related to an output terminal of the plurality of semiconductor switching elements, a connection unit that connects a first element that is one of the plurality of semiconductor switching elements and a second element that is different from the first element among the plurality of semiconductor switching elements in series via a load to form a series circuit, a power supply unit that outputs an inspection voltage to the series circuit, and an inspection processing unit that supplies the inspection voltage to the first element via the load by turning on the second element, and executes an inspection process to inspect the first element based on the detection value of the voltage and / or current detected by the detection unit during a voltage supply period in which the inspection voltage is supplied to the first element.

[0007] Moreover, a switch module inspection device according to one embodiment of the present invention is a switch module inspection device that electrically inspects a switch module having a first switch pair, a second switch pair, and a third switch pair in which a pair of semiconductor switching elements are connected in series, wherein the first switch pair, the second switch pair, and the third switch pair each include a first control terminal, a second control terminal, a first input terminal, a second input terminal, and an output terminal, and the switch module inspection device includes a first coil, a second coil, and a third coil, a power supply unit that is an inspection power supply for the switch module, an inspection processing unit capable of supplying an electrical signal to the switch module, and a current detection unit, wherein one end of the first coil and one end of the third coil are connected at a first node, the other end of the first coil and one end of the second coil are connected at a second node, and the other end of the second coil and the other end of the third coil are connected at a third node. the switch module is detachably attached, and in a state where the switch module is attached, the first node is connected to an output terminal of the first switch pair, the second node is connected to an output terminal of the second switch pair, the third node is connected to an output terminal of the third switch pair, first input terminals of the first switch pair, the second switch pair, and the third switch pair are connected to a positive pole of the power supply unit, second input terminals of the first switch pair, the second switch pair, and the third switch pair are connected to a negative pole of the power supply unit, first control terminals of the first switch pair, the second switch pair, and the third switch pair are connected to an inspection processing unit, and second control terminals of the first switch pair, the second switch pair, and the third switch pair are connected to an inspection processing unit, and the current detection unit is capable of detecting a current flowing into or flowing out of the first switch pair.

[0008] Moreover, a switching element inspection method according to one embodiment of the present invention is a switching element inspection method for inspecting a plurality of semiconductor switching elements, and includes a connection step of connecting a first element which is one of the plurality of semiconductor switching elements and a second element which is different from the first element among the plurality of semiconductor switching elements in series via a load to form a series circuit, and an inspection processing step of supplying an inspection voltage to the first element via the load by turning on the second element, detecting a voltage and / or a current related to an output terminal of the first element during a voltage supply period in which the inspection voltage is supplied to the first element, and executing an inspection processing to inspect the first element based on the detected value of the voltage and / or current. Effect of the Invention

[0009] The switch module inspection apparatus and switching element inspection method configured as above eliminates the need to replace the relay for switching the inspection voltage. [Brief description of the drawings]

[0010] [Figure 1] 1 is an explanatory diagram for explaining an example of a configuration of a switch module inspection device that executes a switching element inspection method according to an embodiment of the present invention; [Diagram 2] 4 is a flowchart showing an example of the operation of the switch module inspection apparatus shown in FIG. [Diagram 3] 13 is a flowchart illustrating an example of an inspection process. [Figure 4] FIG. 4 is a waveform diagram showing an example of a detection value related to a first element. [Diagram 5] 10 is a waveform diagram showing in detail the waveform A when the first element is off. FIG. [Figure 6] 11 is a waveform diagram showing in detail the waveform B when the first element is on. FIG. [Figure 7] 11 is an explanatory diagram showing the on / off states of semiconductor switches other than the first element in step S21 when testing each semiconductor switch as a first element. FIG. [Figure 8]FIG. 13 is an explanatory diagram showing an example of the configuration of a switch module inspection device when the number of switch pairs is two; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each drawing, the same reference numerals are used to denote the same configuration, and the description thereof will be omitted. The switch module inspection device 1 shown in Fig. 1 is an inspection device for inspecting a switch module SM, and is in a state where the switch module SM is attached.

[0012] The switch module SM is a so-called 6-in-1 switch module in which six semiconductor switches T1H, T1L, T2H, T2L, T3H, and T3L, which are semiconductor switching elements, are sealed in one package. The semiconductor switches T1H, T1L, T2H, T2L, T3H, and T3L are, for example, IGBTs (Insulated Gate Bipolar Transistors).

[0013] The switch module SM includes a switch pair SP1 (first switch pair) in which a semiconductor switch T1H and a semiconductor switch T1L are connected in series, a switch pair SP2 (second switch pair) in which a semiconductor switch T2H and a semiconductor switch T2L are connected in series, a switch pair SP3 (third switch pair) in which a semiconductor switch T3H and a semiconductor switch T3L are connected in series, and external terminals G1H, G1L, P1, N1, U, G2H, G2L, P2, N2, V, G3H, G3L, P3, N3, and W. The first switch pair SP1 includes a first control terminal 11, a second control terminal 12, a first input terminal 13, a second input terminal 14, and an output terminal 15. The second switch pair SP2 includes a first control terminal 21, a second control terminal 22, a first input terminal 23, a second input terminal 24, and an output terminal 25. The third switch pair SP3 includes a first control terminal 31, a second control terminal 32, a first input terminal 33, a second input terminal 34, and an output terminal 35.

[0014] Hereinafter, the semiconductor switches T1H, T1L, T2H, T2L, T3H, and T3L will be collectively referred to as semiconductor switch T.

[0015] The gate of the semiconductor switch T1H is connected to the external terminal G1H, the collector is connected to the external terminal P1, and the emitter is connected to the collector of the semiconductor switch T1L. The gate of the semiconductor switch T1L is connected to the external terminal G1L, and the emitter is connected to the external terminal N1. The connection point between the emitter of the semiconductor switch T1H and the collector of the semiconductor switch T1L is connected to the external terminal U. That is, the first control terminal 11, the second control terminal 12, the first input terminal 13, the second input terminal 14, and the output terminal 15 of the first switch pair SP1 are connected to the external terminals G1H, G1L, P1, N1, and U, respectively.

[0016] The gate of the semiconductor switch T2H is connected to the external terminal G2H, the collector is connected to the external terminal P2, and the emitter is connected to the collector of the semiconductor switch T2L. The gate of the semiconductor switch T2L is connected to the external terminal G2L, and the emitter is connected to the external terminal N2. The connection point between the emitter of the semiconductor switch T2H and the collector of the semiconductor switch T2L is connected to the external terminal V. That is, the first control terminal 21, the second control terminal 22, the first input terminal 23, the second input terminal 24, and the output terminal 25 of the second switch pair SP2 are connected to the external terminals G2H, G2L, P2, N2, and V, respectively.

[0017] The gate of the semiconductor switch T3H is connected to the external terminal G3H, the collector is connected to the external terminal P3, and the emitter is connected to the collector of the semiconductor switch T3L. The gate of the semiconductor switch T3L is connected to the external terminal G3L, and the emitter is connected to the external terminal N3. The connection point between the emitter of the semiconductor switch T3H and the collector of the semiconductor switch T3L is connected to the external terminal W. That is, the first control terminal 31, the second control terminal 32, the first input terminal 33, the second input terminal 34, and the output terminal 35 of the third switch pair SP3 are connected to the external terminals G3H, G3L, P3, N3, and W, respectively.

[0018] The gates of the semiconductor switches T1H, T1L, T2H, T2L, T3H, and T3L correspond to an example of a control terminal, one of the collector and the emitter corresponds to an example of an output terminal, and the other corresponds to an example of an input terminal. The semiconductor switch T is not limited to an IGBT as long as it is a semiconductor switching element. If the semiconductor switch T is a bipolar transistor, the base corresponds to an example of a control terminal, and the collector and the emitter correspond to an example of an output terminal. If the semiconductor switch T is a FET (Field Effect Transistor), the gate corresponds to an example of a control terminal, and the source and the drain correspond to an example of an output terminal.

[0019] In FIG. 1, for convenience of drawing, two each of the external terminals U, V, and W are shown, but one each of the external terminals U, V, and W may be sufficient.

[0020] The switch module inspection device 1 includes a plurality of first voltage detection units 2 and second voltage detection units 3, a plurality of current detection units 4, a power supply unit 5, an inspection processing unit 6, a plurality of connection terminals 7, and a connection unit 8. The connection unit 8 includes a coil L1 (first coil), a coil L2 (second coil), a coil L3 (third coil), and wiring 81, 82, and 83. The coils L1, L2, and L3 correspond to an example of a load. Note that the load is not limited to a coil, and may be a resistive load or the like.

[0021] The first voltage detection unit 2, the second voltage detection unit 3, and the current detection unit 4 are provided corresponding to the plurality of semiconductor switches T, respectively.

[0022] The number of connection terminals 7 provided is the same as the number of external terminals of the switch module SM. Each connection terminal 7 is in contact with and conductive with the external terminals G1H, G1L, P1, N1, U, G2H, G2L, P2, N2, V, G3H, G3L, P3, N3, and W, respectively. As a result, the switch module SM to be inspected and the switch module inspection device 1 are electrically connected via the connection terminals 7. Furthermore, the switch module inspection device 1 is capable of detaching and replacing the switch module SM.

[0023] One end of the wiring 81 is connected to the connection terminal 7 in contact with the external terminal U. The other end of the wiring 81 is connected to a first node 41 which is a connection point between one end of the coil L1 and one end of the coil L3. One end of the wiring 82 is connected to the connection terminal 7 in contact with the external terminal V. The other end of the wiring 82 is connected to a second node 42 which is a connection point between the other end of the coil L1 and one end of the coil L2. One end of the wiring 83 is connected to the connection terminal 7 in contact with the external terminal W. The other end of the wiring 83 is connected to a third node 43 which is a connection point between the other end of the coil L2 and the other end of the coil L3.

[0024] One end of the coil L1 is connected to an external terminal U by a wire 81. Furthermore, the other end of the coil L1 is connected to an external terminal V by a wire .

[0025] One end of the coil L2 is connected to an external terminal V by a wire 82. Furthermore, the other end of the coil L2 is connected to an external terminal W by a wire 83.

[0026] One end of the coil L3 is connected to an external terminal W by a wire 83. Furthermore, the other end of the coil L3 is connected to an external terminal U by a wire 81.

[0027] The power supply unit 5 is a power supply circuit that outputs a voltage for inspection, and is a power supply for inspection of the switch module SM. The positive pole of the power supply unit 5 is connected to the external terminal P1 via the current detection unit 4 and connection terminal 7 corresponding to the semiconductor switch T1H, connected to the external terminal P2 via the current detection unit 4 and connection terminal 7 corresponding to the semiconductor switch T2H, and connected to the external terminal P3 via the current detection unit 4 and connection terminal 7 corresponding to the semiconductor switch T3H.

[0028] The negative pole of the power supply unit 5 is connected to an external terminal N1 via a current detection unit 4 and connection terminal 7 corresponding to the semiconductor switch T1L, connected to an external terminal N2 via a current detection unit 4 and connection terminal 7 corresponding to the semiconductor switch T2L, and connected to an external terminal N3 via a current detection unit 4 and connection terminal 7 corresponding to the semiconductor switch T3L.

[0029] As a result, the power supply unit 5 supplies the inspection voltage in parallel to the switch pairs SP1, SP2, and SP3.

[0030] The first voltage detection unit 2 and the second voltage detection unit 3 are voltage measurement circuits configured using, for example, a voltage divider circuit, a voltage differential probe, an analog-to-digital converter, etc. Each of the first voltage detection units 2 and each of the second voltage detection units 3 transmits the detection values ​​of the gate-emitter voltage Vge and the collector-emitter voltage Vce detected from the corresponding semiconductor switch T to the inspection processing unit 6.

[0031] Each first voltage detection unit 2 detects the gate-emitter voltage Vge of each semiconductor switch T by detecting the voltage between the external terminals G1H, G1L, G2H, G2L, G3H, G3L and the external terminals P1, N1, P2, N2, P3, N3 via the connection terminal 7.

[0032] Each second voltage detection unit 3 detects the collector-emitter voltage Vce of each semiconductor switch T by detecting the voltage between the external terminals P1, N1 and the external terminal U, between the external terminals P2, N2 and the external terminal V, and between the external terminals P3, N3 and the external terminal W via the connection terminal 7.

[0033] The current detection units 4 are current measurement circuits configured using, for example, a Hall element, a wound coil, a magnetic core, a shunt resistor, a current probe, an analog-to-digital converter, etc. Each current detection unit 4 transmits a detection value of a current Ic flowing through a corresponding semiconductor switch T to the inspection processing unit 6.

[0034] The first voltage detection unit 2, the second voltage detection unit 3, and the current detection unit 4 may be configured using a digital oscilloscope capable of outputting detection values ​​to the outside. Moreover, the first voltage detection unit 2, the second voltage detection unit 3, and the current detection unit 4 do not necessarily need to be provided corresponding to each semiconductor switch T. By switching the detection points using a switching circuit, the number of the first voltage detection unit 2, the second voltage detection unit 3, and the current detection unit 4 may be less than the number of the semiconductor switches T. Moreover, the switch module inspection device 1 may include the current detection unit 4, but not the first voltage detection unit 2 and the second voltage detection unit 3. Moreover, the switch module inspection device 1 may include the first voltage detection unit 2 or the second voltage detection unit 3, but not the current detection unit 4.

[0035] The inspection processing unit 6 includes, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a RAM (Random Access Memory) that temporarily stores data, a non-volatile storage device such as an SSD (Solid State Drive) or an HDD (Hard Disk Drive), a timer circuit, and peripheral circuits thereof, etc. The inspection processing unit 6 operates by executing a control program that is stored in advance in the above-mentioned storage device, for example.

[0036] When the semiconductor switch T1H on the high potential side of the switch pair SP1 is regarded as a first element, the inspection processing unit 6 regards the semiconductor switches T2L, T3L on the low potential side of the switch pairs SP2, SP3 as second elements, supplies an inspection voltage to the first element via coils L1, L3 (load) by turning on the second element, and inspects the first element based on the gate-emitter voltage Vge, collector-emitter voltage Vce, and current Ic detected by the first voltage detection unit 2, second voltage detection unit 3, and current detection unit 4 during a voltage supply period in which the inspection voltage is supplied to the first element. That is, the inspection processing unit 6 is capable of supplying an electric signal to the switch module SM.

[0037] In addition, when the inspection processing unit 6 regards the semiconductor switch T1L on the low potential side of the switch pair SP1 as the first element, it regards the semiconductor switches T2H, T3H on the high potential side of the switch pair SP2, SP3 as the second element, and supplies an inspection voltage to the first element via coils L1, L3 (load) by turning on the second element, and inspects the first element based on the gate-emitter voltage Vge, collector-emitter voltage Vce, and current Ic detected by the first voltage detection unit 2, the second voltage detection unit 3, and the current detection unit 4 during the voltage supply period in which the inspection voltage is supplied to the first element.

[0038] The inspection processing unit 6 inspects the switch pair SP2, SP3 in the same manner as in the case of the switch pair SP1, with the first element and the second element interchanged. Specific inspection processing of the switch pairs SP2, SP3 will be described later.

[0039] Next, a description will be given of the operation of the switch module inspection apparatus 1 configured as described above. First, at timing t0, all the semiconductor switches T are turned off with reference to Fig. 2 and Fig. 4.

[0040] Next, in step S1, the inspection processing unit 6 sets the semiconductor switch T1H as a first element to be inspected in step S2, and sets the semiconductor switches T2L and T3L as second elements for switching an inspection voltage.

[0041] Next, in step S2, the inspection processing unit 6 executes the inspection process, which is basically based on an inspection method known as a double pulse test.

[0042] 3, at timing t1 in step S21, in the inspection process, the inspection processor 6 turns off the first element (semiconductor switch T1H), turns on the second element (semiconductor switches T2L, T3L), and turns off elements other than the first and second elements. As a result, in the series circuit of the first element (semiconductor switch T1H), coil L1 (load), and second element (semiconductor switch T2L) and the series circuit of the first element (semiconductor switch T1H), coil L3 (load), and second element (semiconductor switch T3L) formed by the connection unit 8, an inspection voltage is applied to the first element (semiconductor switch T1H), and the collector-emitter voltage Vce of the first element (semiconductor switch T1H) rises at timing t1.

[0043] In this case, the test voltage is switched by semiconductor switches T2L, T3L (second elements) provided in the switch module SM, which is the object to be tested. On the other hand, when a mechanical relay is used to switch the test voltage, as in the background art, the mechanical relay has a lifespan based on the number of times it can be opened and closed, and generally needs to be replaced after about tens of thousands of times. For example, if the relay is opened and closed 150 times per hour for testing, and the testing is performed for 12 hours a day, the relay will need to be replaced after 27 days. For this reason, the testing device needs to be equipped with a structure that enables the relay to be replaced, and the relay replacement work will occur.

[0044] On the other hand, according to the switch module inspection device 1, since the inspection voltage is switched by the semiconductor switches T2L, T3L (second elements) of the switch module SM to be inspected, there is no need to provide a switching element for switching the inspection voltage on the inspection device side, and there is no need to consider the life of the switching element. Therefore, the switch module inspection device 1 does not require replacement of the relay for switching the inspection voltage, and there is no need to have a relay replacement structure, so that it is easy to simplify the structure.

[0045] In addition, the switching speed of a mechanical relay is generally around 100 msec, whereas that of a semiconductor switching element is generally around 10 μsec, making the switching speed 10,000 times faster, which makes it easier to shorten the inspection time.

[0046] Furthermore, while mechanical relays are large in size and therefore the inspection device is large in size, the switch module inspection device 1 does not need to include a relay and can therefore be easily made smaller.

[0047] Next, at timing t2 in step S22, the inspection processing unit 6 turns on the first element (semiconductor switch T1H). As a result, a current flows through the first element (semiconductor switch T1H) via the coils L1 and L3, and the current Ic of the first element (semiconductor switch T1H) gradually increases.

[0048] At this time, the current supplied to the first element (semiconductor switch T1H) is divided into coils L1 to L3 and supplied to the first element (semiconductor switch T1H). For example, if 1600 A needs to flow for inspection of the first element (semiconductor switch T1H), 800 A flows to each of the coils L1 and L3. That is, by providing the connection portion 8 and turning on the two second elements (semiconductor switches T2L and T3L), the current flowing through the coils L1 and L3 can be reduced. As a result, small and inexpensive coils can be used as the coils L1 and L3. Furthermore, by reducing the current flowing through the coils L1 and L3, the energy loss occurring in the coils L1 and L3 can be reduced.

[0049] As described later, when the first elements are semiconductor switches T2H and T2L, the current flowing through the coils L1 and L2 can be reduced to half of the test current, and when the first elements are semiconductor switches T3H and T3L, the current flowing through the coils L2 and L3 can be reduced to half of the test current. As a result, small, inexpensive coils can be used as the coils L1 to L3, and the energy loss occurring in the coils L1 to L3 can be reduced.

[0050] Next, at timing t3 in step S23, the inspection processing unit 6 turns off the first element (semiconductor switch T1H). Next, in step S24, the inspection processing unit 6 measures the off delay time Td(off), fall time Tf, fall delay time Toff, and off loss Eoff based on the gate-emitter voltage Vge, collector-emitter voltage Vce, and current Ic of the first element (semiconductor switch T1H).

[0051] Referring to FIG. 5, the off delay time Td(off) is, for example, the time from when a signal to turn off the first element (semiconductor switch T1H) is applied to the gate of the semiconductor switch T1H and the gate-emitter voltage Vge drops to 90% until the current Ic starts to fall (drops to 90%).

[0052] The fall time Tf is, for example, the time it takes for the current Ic flowing through the first element (semiconductor switch T1H) to decrease from 90% to 10%.

[0053] The fall delay time Toff is, for example, the time from when a signal to turn off the first element (semiconductor switch T1H) is applied to the gate of the semiconductor switch T1H and the gate-emitter voltage Vge drops to 90% to when the current Ic falls (drops to 10%).

[0054] The off-state loss Eoff is, for example, the loss generated in the first element (semiconductor switch T1H) when it is turned off. The off-state loss Eoff corresponds to the area of ​​the hatched portion in FIG.

[0055] Next, in step S25, the inspection processing unit 6 inspects the first element based on the off delay time Td(off), the fall time Tf, the fall delay time Toff, and the off-time loss Eoff.

[0056] Specifically, the inspection processing unit 6 compares the measured values ​​of the off delay time Td(off), fall time Tf, fall delay time Toff, and off loss Eoff measured in step S24 with preset reference ranges for the off delay time Td(off), fall time Tf, fall delay time Toff, and off loss Eoff, and inspects whether the first element (semiconductor switch T1H) is a non-defective product based on whether the measured values ​​are within the reference ranges.

[0057] Next, at timing t4 in step S26, the inspection processing unit 6 turns on the first element (semiconductor switch T1H). As a result, a current flows through the first element (semiconductor switch T1H) via the coils L1 and L3, and the current Ic of the first element (semiconductor switch T1H) gradually increases.

[0058] Next, in step S27, the inspection processing unit 6 measures the on-delay time Td(on), rise time Tr, rise delay time Ton, and on-time loss Eon based on the gate-emitter voltage Vge, collector-emitter voltage Vce, and current Ic of the first element (semiconductor switch T1H).

[0059] Referring to FIG. 6, the on-delay time Td(on) is the time from when a signal that turns on the first element (semiconductor switch T1H) is applied to the gate of the semiconductor switch T1H and the gate-emitter voltage Vge rises to 10% until the current Ic starts to flow (increases to 10%).

[0060] The rise time Tr is the time it takes for the current Ic flowing through the first element (semiconductor switch T1H) to increase from 10% to 90%.

[0061] The rise delay time Ton is the time from when a signal that turns on the first element (semiconductor switch T1H) is applied to the gate of the semiconductor switch T1H and the gate-emitter voltage Vge rises to 10% until the current Ic rises (increases to 90%).

[0062] The on-state loss Eon is the loss that occurs in the first element (semiconductor switch T1H) when it is on. The on-state loss Eon corresponds to the area of ​​the hatched portion in FIG.

[0063] Next, in step S28, the inspection processing unit 6 inspects the first element based on the on-delay time Td(on), the rise time Tr, the rise delay time Ton, and the on-loss Eon.

[0064] Specifically, the inspection processing unit 6 compares the measured values ​​of the on-delay time Td(on), rise time Tr, rise delay time Ton, and on-loss Eon measured in step S27 with preset reference ranges for the on-delay time Td(on), rise time Tr, rise delay time Ton, and on-loss Eon, and inspects whether the first element (semiconductor switch T1H) is a non-defective product based on whether the measured values ​​are within the reference ranges.

[0065] Next, at timing t5 in step S29, the inspection processing unit 6 turns off all the semiconductor switches T, and returns to the step from which the inspection process was called. The period from timing t1 to t5 corresponds to the voltage supply period.

[0066] Next, in step S3, the inspection processing unit 6 sets the semiconductor switch T1L as the first element to be inspected in step S4, and sets the semiconductor switches T2H and T3H as the second elements for switching the inspection voltage. Next, in step S4, the inspection processing unit 6 executes the inspection process. The inspection process in step S4 is similar to the above-mentioned steps S21 to S29 except that the first element and the second element are different, so the description thereof will be omitted.

[0067] Next, in step S5, the inspection processing unit 6 sets the semiconductor switch T2H as the first element to be inspected in step S6, and sets the semiconductor switches T1L and T3L as the second elements for switching the inspection voltage. Next, in step S6, the inspection processing unit 6 executes the inspection process. The inspection process in step S6 is similar to the above-mentioned steps S21 to S29 except that the first element and the second element are different, so the description thereof will be omitted.

[0068] Next, in step S7, the inspection processing unit 6 sets the semiconductor switch T2L as the first element to be inspected in step S8, and sets the semiconductor switches T1H and T3H as the second elements for switching the inspection voltage. Next, in step S8, the inspection processing unit 6 executes the inspection process. The inspection process in step S8 is similar to the above-mentioned steps S21 to S29 except that the first element and the second element are different, so the description thereof will be omitted.

[0069] Next, in step S9, the inspection processing unit 6 sets the semiconductor switch T3H as the first element to be inspected in step S10, and sets the semiconductor switches T1L and T2L as the second elements for switching the inspection voltage. Next, in step S10, the inspection processing unit 6 executes the inspection process. The inspection process in step S10 is similar to the above-mentioned steps S21 to S29 except that the first element and the second element are different, so the description thereof will be omitted.

[0070] Next, in step S11, the inspection processing unit 6 sets the semiconductor switch T3L as the first element to be inspected in step S11, and sets the semiconductor switches T1H and T2H as the second elements for switching the inspection voltage. Next, in step S12, the inspection processing unit 6 executes an inspection process. The inspection process in step S12 is similar to the above-mentioned steps S21 to S29 except that the first element and the second element are different, so a description thereof will be omitted.

[0071] As described above, steps S1 to S12 enable testing of all semiconductor switches T. Fig. 7 shows that, for example, when the first element is semiconductor switch T1H, semiconductor switches T1L, T2H, T2L, T3H, and T3L are "off, off, on, off, on", and that, for example, when the first element is semiconductor switch T2L, semiconductor switches T1H, T1L, T2H, T3H, and T3L are "on, off, off, on, off".

[0072] Although an example has been shown in which the switch module SM includes three switch pairs SP1, SP2, and SP3, the number of switch pairs is not limited to three and may be any number as long as it is more than one.

[0073] 8 inspects a switch module SMa including two switch pairs SP1 and SP2. The switch module inspection device 1a includes four first voltage detection units 2, four second voltage detection units 3, and four current detection units 4 corresponding to the four semiconductor switches T1H, T1L, T2H, and T2L included in the switch pairs SP1 and SP2. The connection unit 8a includes wiring 81 and 82 and a coil L1, but does not include wiring 83 or coils L2 and L3.

[0074] When the inspection processing unit 6a regards the high-potential side semiconductor switch T1H of switch pair SP1, which is one of the multiple switch pairs SP1, SP2, as the first element, it performs inspection processing using the low-potential side semiconductor switch T2L of switch pair SP2, which is a switch pair different from switch pair SP1, as the second element, and when the low-potential side semiconductor switch T1L of switch pair SP1 is the first element, it performs inspection processing using the high-potential side semiconductor switch T2H of switch pair SP2 as the second element.

[0075] According to a switching element testing method according to an embodiment of the present invention, the multiple switch pairs SP1, SP2, and SP3 do not necessarily have to be switch modules SM sealed in one package.

[0076] In addition, the inspection process is not limited to an example in which inspection is performed based on all of the off delay time Td(off), fall time Tf, fall delay time Toff, off-time loss Eoff, on-delay time Td(on), rise time Tr, rise delay time Ton, and on-time loss Eon, and it is sufficient to perform inspection based on at least one of these.

[0077] The inspection process is not limited to the example of inspecting at least one of the off delay time Td(off), fall time Tf, fall delay time Toff, off loss Eoff, on delay time Td(on), rise time Tr, rise delay time Ton, and on loss Eon, and other inspections may be performed. Also, the inspection process does not have to be based on the so-called double pulse test. [Explanation of symbols]

[0078] 1,1a Switch module inspection equipment 2 First voltage detection section 3 Second voltage detection section 4 Current detection section 5 Power supply section 6,6a Inspection processing section 7 Connection terminal 8,8a Connection 11, 21, 31 First control terminal 12, 22, 32 Second control terminal 13,23,33 First input terminal 14,24,34 Second input terminal 15,25,35 Output terminal 41 First Node 42 Second Node 43 Third Node 81,82,83 Wiring A OFF Waveform B On-time waveform Eoff: Loss when off Eon On-state loss G1H,G1L,P1,N1,U,G2H,G2L,P2,N2,V,G3H,G3L,P3,N3,W External terminal IC current L1 coil (first coil, load) L2 coil (second coil, load) L3 coil (third coil, load) SM, SMa switch module SP1 switch pair (first switch pair) SP2 switch pair (second switch pair) SP3 switch pair (third switch pair) T, T1H, T1L, T2H, T2L, T3H, T3L Semiconductor switches (semiconductor switching elements) Td(off) Off delay time Td(on) On delay time Tf Fall time Toff Falling delay time Ton Rise delay time Tr Rise Time Vce Collector-emitter voltage Vge Gate-emitter voltage

Claims

1. A switch module inspection device for inspecting a switch module including a plurality of semiconductor switching elements, comprising: a detection unit for detecting a voltage and / or a current related to an output terminal or an input terminal of the plurality of semiconductor switching elements; a connection section that configures a series circuit by connecting a first element, which is one of the plurality of semiconductor switching elements, and a second element, which is different from the first element, among the plurality of semiconductor switching elements, in series via a load; A power supply unit that outputs a test voltage to the series circuit; a test processing unit that supplies the test voltage to the first element via the load by turning on the second element, and performs a test process to test the first element based on the detection value of the voltage and / or current detected by the detection unit during a voltage supply period in which the test voltage is supplied to the first element.

2. The switch module includes a plurality of switch pairs, each of which includes a pair of the semiconductor switching elements connected in series, the power supply unit supplies the inspection voltage in parallel to the plurality of switch pairs; the connection unit connects connection points of the pair of semiconductor switching elements in each of the switch pairs via the load, The inspection processing unit includes: When the semiconductor switching element on the high potential side of a first switch pair, which is one of the plurality of switch pairs, is defined as the first element, the inspection process is performed with the semiconductor switching element on the low potential side of a second switch pair, which is a switch pair different from the first switch pair, defined as the second element.

2. A switch module testing device as described in claim 1, wherein when the semiconductor switching element on the low potential side of the first switch pair is defined as the first element, the semiconductor switching element on the high potential side of the second switch pair is defined as the second element and the testing process is performed.

3. the switch module includes three switch pairs, a first switch pair, a second switch pair, and a third switch pair; the power supply unit supplies the inspection voltage in parallel to the first, second, and third switch pairs; the connection unit connects connection points of the pair of semiconductor switching elements in the first, second, and third switch pairs to each other via the load; The inspection processing unit includes: When the semiconductor switching element on the high potential side of the first switch pair is defined as the first element, the semiconductor switching element on the low potential side of the second and third switch pairs is defined as the second element, and the inspection process is performed; A switch module inspection device as described in claim 1, wherein when the semiconductor switching element on the low potential side of the first switch pair is defined as the first element, the inspection process is performed with the semiconductor switching element on the high potential side of the second and third switch pairs as the second element.

4. 4. The switch module inspection device according to claim 1, wherein the load is a coil.

5. The load is a first coil connected between a connection point of the pair of semiconductor switching elements in the first switch pair and a connection point of the pair of semiconductor switching elements in the second switch pair; a second coil connected between a connection point of the pair of semiconductor switching elements in the second switch pair and a connection point of the pair of semiconductor switching elements in the third switch pair; 4. The switch module inspection device according to claim 3, further comprising a third coil connected between a connection point of the pair of semiconductor switching elements in the third switch pair and a connection point of the pair of semiconductor switching elements in the first switch pair.

6. The inspection processing unit, in the inspection process, When the first element is changed from OFF to ON during the voltage supply period, 6. A switch module inspection device according to claim 1, wherein the first element is inspected based on at least one of an on-delay time from when a signal to turn on the first element is applied to a control terminal of the first element until a current starts to flow through the first element, a rise time of the current flowing through the first element, a rise delay time from when a signal to turn on the first element is applied to the control terminal of the first element until the current flowing through the first element rises, and an on-time loss generated in the first element.

7. The inspection processing unit, in the inspection process, When the first element is changed from on to off during the voltage supply period, 7. A switch module inspection device according to claim 1, wherein the first element is inspected based on at least one of an off delay time from when a signal for turning off the first element is applied to a control terminal of the first element until a current flowing through the first element starts to fall, a fall time of the current flowing through the first element, a fall delay time from when a signal for turning off the first element is applied to the control terminal of the first element until a current flowing through the first element falls, and an off-time loss generated in the first element.

8. A switch module inspection device as described in any one of claims 1 to 7, wherein the inspection processing unit repeats the inspection process while replacing the first switch pair and the second switch pair with other semiconductor switching elements among the plurality of semiconductor switching elements.

9. A switch module inspection device for electrically inspecting a switch module having a first switch pair, a second switch pair, and a third switch pair, each of which is a pair of semiconductor switching elements connected in series, comprising: each of the first switch pair, the second switch pair, and the third switch pair includes a first control terminal, a second control terminal, a first input terminal, a second input terminal, and an output terminal; The switch module inspection device includes a first coil, a second coil, and a third coil, a power supply unit which is a power supply for testing the switch module; an inspection processing unit capable of supplying an electrical signal to the switch module; A current detection unit, one end of the first coil and one end of the third coil are connected at a first node; the other end of the first coil and one end of the second coil are connected at a second node; the other end of the second coil and the other end of the third coil are connected at a third node; The switch module is detachable, With the switch module attached, the first node is connected to an output terminal of the first switch pair; the second node is connected to an output terminal of the second switch pair; the third node is connected to an output terminal of the third switch pair; a first input terminal of each of the first switch pair, the second switch pair, and the third switch pair is connected to a positive electrode of the power supply unit; a second input terminal of each of the first switch pair, the second switch pair, and the third switch pair is connected to a negative electrode of the power supply unit; a first control terminal of each of the first switch pair, the second switch pair, and the third switch pair is connected to an inspection processing unit; second control terminals of the first switch pair, the second switch pair, and the third switch pair are connected to an inspection processing unit; The switch module inspection device, wherein the current detection unit is capable of detecting a current flowing into or out of the first switch pair.

10. A first voltage detection unit is further provided, 10. The switch module inspection device according to claim 9, wherein the first voltage detection unit is capable of measuring a voltage between an output terminal of the first switch pair and a first input terminal of the first switch pair, or a voltage between an output terminal of the first switch pair and a second input terminal of the first switch pair.

11. A second voltage detection unit is further provided, 11. The switch module inspection device according to claim 9 or 10, wherein the second voltage detection unit is capable of measuring a voltage between a first control terminal of the first switch pair and a first input terminal of the first switch pair, or a voltage between a second control terminal of the first switch pair and a second input terminal of the first switch pair.

12. A switching element inspection method for inspecting a plurality of semiconductor switching elements, comprising the steps of: a connection step of connecting a first element, which is one of the plurality of semiconductor switching elements, and a second element, which is different from the first element, of the plurality of semiconductor switching elements in series via a load to form a series circuit; a test processing step of supplying a test voltage to the first element via the load by turning on the second element, detecting a voltage and / or a current related to an output terminal or an input terminal of the first element during a voltage supply period in which the test voltage is supplied to the first element, and performing a test processing step of testing the first element based on the detected value of the voltage and / or current.

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