JP2019086306A - Testing device of semiconductor device - Google Patents

Abstract

To provide a technique that can simultaneously perform both of a switching characteristic test and a screening test.SOLUTION: A semiconductor device comprises: a switching element that has a gate terminal, a first terminal, and a second terminal, and switches between the first terminal and the second terminal according to potential of the gate terminal; a temperature sense diode; and a Zener diode coupled between the second terminal and the temperature sense diode. A testing device comprises: first wiring that couples the first terminal with the second terminal; a power supply that is disposed on the first wiring in a direction so that a positive electrode is directed to a first terminal side; a load that is disposed on the first wiring in series to the power supply; a gate power supply that controls the potential of the gate terminal; and second wiring that is coupled to the Zener diode or the temperature sense diode, and has a parallel running section which runs in parallel with the first wiring.SELECTED DRAWING: Figure 1

Description

  The technology disclosed in the present specification relates to a test apparatus for a semiconductor device.

  2. Description of the Related Art There is known a test apparatus which performs switching characteristic test and screening test of a semiconductor device having a switching element. In the switching characteristic test, a change in current flowing between main terminals of the semiconductor device is detected by controlling the voltage of the gate terminal of the semiconductor device to be tested. Further, in the screening test, a voltage is applied between predetermined terminals of the semiconductor device to be tested to detect a defect in the wiring shape and foreign matter existing between the wirings. By this, a defective semiconductor device is screened.

  Patent Document 1 discloses a technology capable of performing both the switching characteristic test and the screening test with a single test device. In this test apparatus, it is described that both the switching characteristic test and the screening test can be appropriately performed by making the inductance of the inductor provided in the circuit variable.

JP, 2017-138126, A

  The present specification provides a technology capable of simultaneously performing both the switching characteristic test and the screening test with a configuration different from that of Patent Document 1.

  This specification discloses a test apparatus for a semiconductor device. The semiconductor device has a switching element, a temperature sense diode, and a zener diode. The switching element has a gate terminal, a first terminal, and a second terminal, and switches between the first terminal and the second terminal according to the potential of the gate terminal. The zener diode is connected between the second terminal and the temperature sense diode. The test apparatus includes a first wiring, a power supply, a load, a gate power supply, and a second wiring. The first wiring connects the first terminal and the second terminal. The power supply is interposed in the first wiring in a direction in which a positive electrode faces the first terminal. The load is interposed in the first wiring in series with the power supply. The gate power supply controls the potential of the gate terminal. The second wiring is connected to the zener diode or the temperature sense diode, and has a parallel running section parallel to the first wiring.

  In the above test apparatus, the semiconductor device is controlled between the on state and the off state by the gate power supply controlling the potential of the gate terminal. Thus, the switching characteristic test of the semiconductor device can be performed. When the semiconductor device is turned on or off, the current flowing to the first wiring changes. When the current flowing in the first wiring changes, a current flows in the second wiring parallel to the first wiring by electromagnetic induction. As a result, a voltage is applied to at least one of the temperature sense diode and the zener diode. Thus, the screening test can be performed on at least one of the temperature sense diode and the zener diode. As described above, according to the above-mentioned test apparatus, both the switching characteristic test and the screening test can be performed simultaneously.

FIG. 2 is a circuit diagram of a test apparatus 10. FIG. 7 is a timing chart showing the operation of the test apparatus 10. FIG. 7 is a view showing a change in current flowing through the first wire 22 and a change in voltage applied to the second wire 24. The circuit diagram of the test apparatus 10a of a modification. The circuit diagram of the test apparatus 10b of another modification. The circuit diagram of the test apparatus 10c of another modification.

  The test apparatus 10 of the embodiment will be described with reference to the drawings. FIG. 1 shows a circuit diagram of a test apparatus 10. The test apparatus 10 tests the semiconductor device 20. The test apparatus 10 includes a first wiring 22, a second wiring 24, a power supply 26, an inductor 28, a diode 30, a gate resistor 32, and a gate power supply 34.

  The semiconductor device 20 has a main switching element M1 and a sense switching element M2. In the present embodiment, the main switching element M1 and the sense switching element M2 are IGBTs (Insulated Gate Bipolar Transistors). The main switching element M1 and the sense switching element M2 are provided on the same semiconductor substrate and have the same unit structure (IGBT), but the sense switching element M2 is smaller than the main switching element M1. Since a minute current substantially proportional to the main switching element M1 flows in the sense switching element M2, the current flowing in the main switching element M1 can be grasped by detecting the minute current. The semiconductor device 20 does not necessarily have to have the sense switching element M2.

  The main switching element M1 has a gate terminal g1, a collector terminal c1, and an emitter terminal e1. The sense switching element M2 has a gate terminal g2, a collector terminal c2, and an emitter terminal e2. The gate terminal g2 is connected to the gate terminal g1, the collector terminal c2 is connected to the collector terminal c1, and the emitter terminal e2 is connected to the emitter terminal e1.

  The gate terminal g1 is connected to the gate power supply 34 via the gate resistor 32. As the gate power supply 34 controls the potential of the gate terminal g1, the main switching element M1 receives an on state in which current flows between the collector terminal c1 and the emitter terminal e1, and a current between the collector terminal c1 and the emitter terminal e1. It is switched to the off state where it does not flow. Further, the sense switching element M2 is switched by the gate power supply 34 at the same timing as the main switching element M1. The gate power supply 34 is connected to the emitter terminal e1. That is, the gate terminal g1 is connected to the emitter terminal e1 via the gate resistor 32 and the gate power supply 34.

  The collector terminal c1 and the emitter terminal e1 are connected by the first wiring 22. A power supply 26 is interposed in the first wiring 22. The power supply 26 is interposed in the first wiring 22 such that the positive electrode faces the collector terminal c1. Further, an inductor 28 is interposed in series with the power supply 26 in the first wiring 22. Specifically, one end of the inductor 28 is connected to the positive electrode of the power supply 26, and the other end is connected to the collector terminal c1. The diode 30 is connected in parallel to the inductor 28. The anode of the diode 30 is connected to the collector terminal c 1, and the cathode is connected to the positive electrode of the power supply 26. The diode 30 is provided to return the current flowing to the inductor 28 when the semiconductor device 20 switches from the on state to the off state.

  The semiconductor device 20 further includes a first temperature sense diode 52, a second temperature sense diode 54, a first Zener diode 56, and a second Zener diode 58.

  The anode of the first Zener diode 56 is connected to the emitter terminal e1. The cathode of the second Zener diode 58 is connected to the cathode of the first Zener diode 56. The anode of the first temperature sense diode 52 is connected to the anode of the second Zener diode 58. Further, a second temperature sense diode 54 is connected in antiparallel to the first temperature sense diode 52 to the anode of the second Zener diode 58. That is, the cathode of the second temperature sense diode 54 is connected to the anode of the second Zener diode 58. The cathode of the first sense diode 52 and the anode of the second sense diode 54 are connected to a common wire.

  A second wire 24 is connected to the anode of the second Zener diode 58, the anode of the first temperature sense diode 52, and the cathode of the second temperature sense diode 54. That is, the second wiring 24 is connected to the emitter terminal e1 of the main switching element M1 via the second Zener diode 58 and the first Zener diode 56.

  The second wiring 24 has a parallel running section L1 that runs parallel to the first wiring 22. In the present embodiment, the parallel running section L1 is provided on the first wiring 22 in the range between the positive electrode of the power supply 26 and the collector terminal c1 of the main switching element M1. Specifically, the parallel running section L1 is provided closer to the power supply 26 than the closed circuit of the inductor 28 and the diode 30. In the present embodiment, the length of the parallel running section L1 is 600 mm. Moreover, the distance between the first wiring 22 and the second wiring 24 in the parallel running section L1 is 4 mm. The length of the parallel running section L1 and the distance between the first wiring 22 and the second wiring 24 in the parallel running section L1 are not particularly limited.

  Next, the operation when the switching characteristic test and the screening test of the semiconductor device 20 are performed using the test apparatus 10 will be described. In the test apparatus 10, the gate power supply 34 controls the potentials of the gate terminal g1 of the main switching element M1 and the gate terminal g2 of the sense switching element M2 to control the semiconductor device 20 between the on state and the off state. Thereby, the switching characteristic test of the semiconductor device 20 can be performed.

  FIG. 2 shows a change in each value of the main switching element M1 when the switching characteristic test of the semiconductor device 20 is performed. The reference symbol VGE indicates the potential of the gate terminal g1 of the main switching element M1. The reference symbol VCE indicates the potential of the collector terminal c1 of the main switching element M1. Reference numeral ICE indicates a current flowing through the main switching element M1. The reference symbol IK indicates the current flowing through the second wire 24. The reference symbol VK indicates the potential of the second wiring 24. The sense switching element M2 is also switched in the same manner as the main switching element M1, and thus the description thereof is omitted here.

  At timing t0 in FIG. 2, since the gate power supply 34 is at the off potential (that is, a potential lower than the gate threshold), the main switching element M1 is off. Therefore, the current ICE does not flow between the collector terminal c1 and the emitter terminal e1 of the main switching element M1, and the potential of the power supply 26 is applied to the collector terminal c1.

  After that, at timing t1, the gate power supply 34 raises the potential of the gate terminal g1 from the off potential to the on potential (that is, a potential higher than the gate threshold). Therefore, the main switching element M1 is turned on. Then, the current ICE starts to flow between the collector terminal c1 and the emitter terminal e1. Therefore, the potential VCE of the collector terminal c1 drops. Since the electromotive force of the inductor 28 gradually decreases after the timing t2, the current ICE gradually increases.

  Thereafter, at timing t2, when the gate power supply 34 decreases the potential VGE of the gate terminal g1 from the on potential to the off potential, the main switching element M1 is turned off. Therefore, the current ICE does not flow between the collector terminal c1 and the emitter terminal e1. As a result, the current flowing through the first wiring 22 is reduced, and an electromotive force is generated in the direction of current flow through the inductor 28. Therefore, the electromotive force of the inductor 28 and the voltage of the power supply 26 are applied to the collector terminal c1. Thus, the potential VCE of the collector terminal c1 instantaneously rises. However, since the current flowing to the inductor 28 is returned by the diode 30, the potential VCE of the collector terminal c1 is controlled to the potential of the power supply 26 after the timing t2.

  In the switching characteristic test, the switching characteristic test of the semiconductor device 20 can be performed by measuring the potential VGE, the potential VCE, the current ICE and the like shown in FIG.

  Next, the screening test will be described. The screening test is performed during the implementation of the switching characteristic test. In the state where the semiconductor device 20 is on (during the timing t1 to t2 in FIG. 2), since the current flows in the first wiring 22, an electric field is generated around the first wiring 22. Thereafter, when the semiconductor device 20 is turned off (timing t2 in FIG. 2), as described above, current flows in the closed circuit of the inductor 28 and the diode 30. As a result, the current flowing through the first wire 22 in the portion connected to the power supply 26 decreases sharply. Therefore, the electric field generated around the first wiring 22 is reduced. In the test apparatus 10 of the present embodiment, the second wiring 24 has a parallel running section L <b> 1 running parallel to the first wiring 22. Therefore, as shown at timing t2 in FIG. 2, a current IK (so-called induced current) flows in the second wiring 24 in a direction to compensate for the electric field generated around the first wiring 22 by electromagnetic induction. As a result, a voltage VK according to the value of the induced current is applied to the anode of the second Zener diode 58. That is, the voltage VK is applied to a series circuit of the second Zener diode 58 and the first Zener diode 56. Further, a voltage corresponding to the change of the voltage VK is applied to the first temperature sense diode 52 and the second temperature sense diode 54. FIG. 3 shows the simulation result of the screening test using the test apparatus 10 of the present embodiment. As shown in FIG. 3, when the current flowing through the first wiring 22 is about 450 A when the semiconductor device 20 is on, the voltage VK has an amplitude of about ± 80 V when the semiconductor device 20 is off. It fluctuates with. As other conditions, the power supply 26 is 600 V, the on potential of the gate power supply 34 is 15 V, the off potential of the gate power supply 34 is 0 V, and the gate resistance 32 is 1 Ω. Thereby, a high voltage can be instantaneously applied to the Zener diodes 56, 58 and the temperature sense diodes 52, 54. Thus, screening tests can be performed by applying loads to the Zener diodes 56, 58 and the temperature sense diodes 52, 54.

  As described above, according to the test apparatus 10 of the present embodiment, both the switching characteristic test and the screening test can be performed simultaneously.

  The collector terminal c1 is an example of the “first terminal”. The emitter terminal e1 is an example of the “second terminal”. The main switching element M1 is an example of the “switching element”. The inductor 28 is an example of the “load”.

  As shown in FIG. 4, in the test apparatus 10a of the modification, the second wiring 24 is parallel to the first wiring 22 in the range between the negative electrode of the power supply 26 and the emitter terminal e1 of the main switching element M1. May be included. Further, as shown in FIG. 5, in the test apparatus 10 b of another modification, the second wire 24 is a first wire 22 in a range between the positive electrode of the power supply 26 and the collector terminal c1 of the main switching element M1, and A parallel running section L3 may be provided which runs parallel to both the first wiring 22 in the range between the negative electrode of the power source 26 and the emitter terminal e1 of the main switching element M1. In this case, the second wiring 24 may have a section running parallel to only the first wiring 22 in the range between the positive electrode of the power supply 26 and the collector terminal c1 of the main switching element M1, or the negative electrode of the power supply 26 and the main There may be a section running parallel to only the first wiring 22 in the range between the emitter terminals e1 of the switching element M1.

  Further, in the test apparatus 10 of the embodiment, the second wire 24 is connected to the anode of the second Zener diode 58, the anode of the first temperature sense diode 52, and the cathode of the second temperature sense diode 54. . However, as shown in FIG. 6, in the test apparatus 10 c of another modification, the second wiring 24 may be connected to the cathode of the first temperature sense diode 52 and the anode of the second temperature sense diode 54. The second wiring 24 may have a parallel running section L4 that runs parallel to the first wiring 22. Further, in the test apparatus 10 of the embodiment, the parallel running section L1 is provided closer to the power supply 26 than the closed circuit of the inductor 28 and the diode 30. However, the parallel running section L1 may be provided closer to the main switching element M1 than the closed circuit of the inductor 28 and the diode 30. The configuration of the second wiring 24 of the test apparatus 10c may be used in a test apparatus of another modification. Also, a resistor may be used in place of the inductor 28 of the test devices 10 to 10c described above.

  Moreover, in each test apparatus mentioned above, IGBT which a current flows from a collector to an emitter was used as a switching element which the semiconductor device of a test object has. However, the technology disclosed in the present specification may be applied to a semiconductor device having another switching element (n-channel MOSFET, p-channel MOSFET, etc.).

  As mentioned above, although the specific example of this invention was described in detail, these are only an illustration and do not limit a claim. The art set forth in the claims includes various variations and modifications of the specific examples illustrated above. The technical elements described in the present specification or the drawings exhibit technical usefulness singly or in various combinations, and are not limited to the combinations described in the claims at the time of application. In addition, the techniques illustrated in the present specification or the drawings simultaneously achieve a plurality of purposes, and achieving one of the purposes itself has technical utility.

10: test apparatus 20: semiconductor device 22: first wiring 24: second wiring 26: power supply 28: inductor 30: diode 32: gate resistance 34: gate power supply 50: switching element 50c: collector terminal 50e: emitter terminal 50g: gate Terminal 52: first temperature sense diode 54: second temperature sense diode 56: first Zener diode 58: second Zener diode L1: parallel running section

Claims (1)

Test equipment for semiconductor devices,
The semiconductor device is
A switching element having a gate terminal, a first terminal, and a second terminal, and switching between the first terminal and the second terminal in accordance with the potential of the gate terminal;
Temperature sense diode,
A zener diode connected between the second terminal and the temperature sense diode;
And have
The test apparatus
A first wire connecting the first terminal and the second terminal;
A power supply interposed in the first wiring in a direction in which a positive electrode faces the first terminal side;
A load interposed in the first wire in series with the power supply;
A gate power supply for controlling the potential of the gate terminal;
A second wire connected to the Zener diode or the temperature sense diode and having a parallel running section running parallel to the first wire;
have,
Test equipment.

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