Testing device and testing method

Abstract

The invention discloses a testing device and a testing method, and the device comprises a chuck which is used for bearing an IGBT wafer; the grounding module is connected with the chuck and is used for grounding the chuck; and the probe card is suspended above the chuck, the probe card is used for testing an IGBT (Insulated Gate Bipolar Translator) wafer, and the probe card is provided with an insulating probe. According to the IGBT wafer testing method and device, wafer-level testing is directly carried out, so that the testing efficiency of the IGBT wafer is improved, meanwhile, the IGBT wafer is tested by grounding the chuck bearing the IGBT wafer and using the probe card with the insulating probe, the probability that the IGBT wafer generates leakage current in the testing process can be reduced, the accuracy of a testing result is improved, and the testing efficiency is improved. Therefore, the reliability of the IGBT wafer can be further improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular to a testing device and a testing method. Background Art

[0002] In recent years, IGBT (Insulated Gate Bipolar Transistor) semiconductor devices have been increasingly used in power electronic equipment and power conversion, especially in industries such as ultra-high voltage direct current transmission, flexible direct current transmission systems, electric vehicles, and high-speed rail. The demand for high-power IGBT semiconductor devices is increasing.

[0003] The lack of rapid testing methods for IGBT semiconductor devices poses a huge threat to the long-term safe and stable operation of the equipment.

[0004] At present, the reliability and detection efficiency of IGBT semiconductor devices still need to be improved. Summary of the invention

[0005] The problem solved by the embodiments of the present invention is to provide a testing device and a testing method, which are beneficial to further improve the testing efficiency and reliability of IGBT wafers.

[0006] To solve the above problems, an embodiment of the present invention provides a testing device, which is used to implement testing of IGBT wafers, including: a chuck, used to carry the IGBT wafer; a grounding module, connected to the chuck, used to ground the chuck; a probe card, suspended above the chuck, the probe card is used to test the IGBT wafer, and the probe card has an insulating probe.

[0007] Optionally, the chuck has an external port; the grounding module is connected to the external port.

[0008] Optionally, the grounding module comprises a grounding algorithm submodule, and the grounding algorithm submodule is used to ground the grounding module.

[0009] Optionally, the probe card has a measurement area and an insulating area between adjacent measurement areas; the insulating probe is located in the insulating area; the probe card further includes: a measurement probe, the measurement probe is located in the measurement area, and the measurement probe is used to test the IGBT wafer.

[0010] Optionally, the insulating probe includes a metal probe and an insulating layer covering the metal probe.

[0011] Optionally, the material of the insulating layer includes epoxy resin.

[0012] Correspondingly, an embodiment of the present invention also provides a testing method, including: providing a testing device provided by an embodiment of the present invention; placing an IGBT wafer on a chuck of the testing device; grounding the chuck; moving the probe card, contacting the probe card with the IGBT wafer, and using the probe card to test the IGBT wafer to determine the reliability of the IGBT wafer.

[0013] Optionally, the IGBT wafer includes a front side and a back side opposite thereto, the front side of the IGBT wafer is formed with a gate and an emitter located on the side of the gate, an isolation structure is formed between the gate and the emitter, and the back side of the IGBT wafer is formed with a collector.

[0014] Optionally, the step of placing an IGBT wafer on a chuck of the testing device includes: placing the IGBT wafer on the chuck with the collector of the IGBT wafer facing the chuck.

[0015] Optionally, the probe card has a measurement area and an insulating area between adjacent measurement areas; the insulating probe is located in the insulating area; the probe card further includes: a measurement probe, the measurement probe is located in the measurement area, and the measurement probe is used to test the IGBT wafer.

[0016] Optionally, the IGBT wafer includes a front side and a back side opposite thereto, a gate and an emitter located on the side of the gate are formed on the front side of the IGBT wafer, an isolation structure is formed between the gate and the emitter, and a collector is formed on the back side of the IGBT wafer; the steps of using the probe card to test the IGBT wafer include: selecting any area to be tested of the IGBT wafer; moving the probe card above the area to be tested; contacting the measuring probe with the gate and the emitter, and contacting the insulating probe with the isolation structure; applying voltage to the gate, and grounding the emitter.

[0017] Optionally, the area of ​​the test area is greater than or equal to 10CM 2 .

[0018] Optionally, the step of judging the reliability of the IGBT wafer includes: the step of judging the reliability of the IGBT wafer includes: measuring an actual leakage current value between a gate and an emitter in the IGBT wafer; comparing the actual leakage current value with an ideal leakage current value of the IGBT wafer, when the actual leakage current value is greater than the ideal leakage current value, the reliability of the IGBT wafer is poor, and when the actual leakage current value is less than the ideal leakage current value, the reliability of the IGBT wafer is good.

[0019] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0020] The testing device provided by the embodiment of the present invention includes a chuck for carrying an IGBT wafer, a grounding module connected to the chuck, the grounding module is used to ground the chuck, and a probe card is used to test the IGBT wafer. The probe card has an insulating probe. Compared with the solution of cutting the IGBT wafer to form a single IGBT and then testing the single IGBT, the embodiment of the present invention directly tests the IGBT wafer, that is, directly performs wafer-level testing, thereby improving the testing efficiency of the IGBT wafer. At the same time, by grounding the chuck carrying the IGBT wafer and using a probe card with an insulating probe to test the IGBT wafer, the probability of the IGBT wafer generating leakage current during the test can be reduced, the accuracy of the test results is improved, and the reliability of the IGBT wafer can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the testing device of the present invention;

[0022] Figure 2 A schematic diagram of the IGBT structure placed on the chuck of the test device of the present invention;

[0023] Figure 3 It is a flow chart of the steps of an embodiment of the testing method of the present invention. DETAILED DESCRIPTION

[0024] From the background technology, it can be seen that the reliability and detection efficiency of IGBT (Insulated Gate Bipolar Transistor) semiconductor devices still need to be improved. At present, the electrical testing of IGBT is mainly carried out by cutting the IGBT wafer into single IGBT, and then electrically testing the single IGBT. This testing scheme is inefficient and requires customization of special probe cards, and the production cost is high. At the same time, the IGBT wafer is not electrically tested before being cut into single IGBTs, resulting in the reliability of the IGBT wafer cannot be guaranteed.

[0025] In order to solve the above technical problems, an embodiment of the present invention provides a testing device, which is used to implement testing of IGBT wafers, including: a chuck, used to carry the IGBT wafer; a grounding module, connected to the chuck, used to ground the chuck; a probe card, suspended above the chuck, the probe card is used to test the IGBT wafer, and the probe card has an insulating probe.

[0026] The testing device provided in the embodiment of the present invention includes a chuck for carrying an IGBT wafer, a grounding module connected to the chuck, the grounding module is used to ground the chuck, and a probe card is used to test the IGBT wafer. The probe card has an insulating probe. Compared with the solution of cutting the IGBT wafer to form a single IGBT and then testing the single IGBT, the embodiment of the present invention directly tests the IGBT wafer, that is, directly performs wafer-level testing, thereby improving the testing efficiency of the IGBT wafer. At the same time, by grounding the chuck carrying the IGBT wafer and using a probe card with an insulating probe to test the IGBT wafer, the probability of leakage current generated by the IGBT wafer during the test can be reduced, the accuracy of the test results is improved, and the reliability of the IGBT wafer can be further improved.

[0027] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and understandable, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] Figure 1 It is a schematic diagram of the structure of the testing device of the present invention; Figure 2 A schematic diagram of the IGBT structure placed on the chuck of the test device of the present invention.

[0029] The testing device is used to implement testing of IGBT wafers, and the testing device includes: a chuck 100, used to carry an IGBT (Insulated Gate Bipolar Transistor) wafer; a grounding module 101, connected to the chuck 100, used to ground the chuck 100; a probe card 102, suspended above the chuck 100, the probe card 102 is used to test the IGBT wafer, and the probe card 102 has an insulating probe 106.

[0030] It should be noted that the testing device includes a chuck 100 for carrying an IGBT wafer, a grounding module 101 connected to the chuck 100, the grounding module 101 is used to ground the chuck 100, and a probe card 102 is used to test the IGBT wafer. The probe card 102 has an insulating probe 106. Compared with the solution of cutting the IGBT wafer to form a single IGBT and then testing the single IGBT, the embodiment of the present invention directly tests the IGBT wafer, that is, directly performs wafer-level testing, thereby improving the testing efficiency of the IGBT wafer. At the same time, by grounding the chuck 100 carrying the IGBT wafer and using the probe card 102 with the insulating probe 106 to test the IGBT wafer, the probability of the IGBT wafer generating leakage current during the test can be reduced, the accuracy of the test results is improved, and the reliability of the IGBT wafer can be further improved.

[0031] It should also be noted that the test on the IGBT wafer specifically refers to the test on the gate breakdown voltage of the IGBT wafer. The reliability of the IGBT wafer can be obtained by testing the gate breakdown voltage of the IGBT wafer.

[0032] The chuck 100 is used to carry the IGBT wafer. Meanwhile, the chuck 100 is also used to fix the IGBT wafer to prevent the risk of movement or falling off during the testing of the IGBT wafer.

[0033] In this embodiment, the chuck 100 has an external connection port 160 .

[0034] The external port 160 is used to connect to the grounding module 101, so that the chuck 100 can be connected to the grounding module 101. In the subsequent testing of the IGBT wafer, the IGBT wafer placed on the chuck 100 can be grounded, reducing the probability of leakage current in the IGBT wafer, thereby improving the accuracy of the test results.

[0035] The grounding module 101 is used to achieve grounding of the chuck 100 .

[0036] As an example, the grounding module 101 includes a grounding algorithm submodule (not shown), and the grounding algorithm submodule is used to ground the grounding module 101.

[0037] The grounding algorithm submodule has a program for setting the grounding module 101 to be grounded. The program can realize the grounding of the grounding module 101, thereby grounding the chuck 100.

[0038] In this embodiment, the grounding module 101 is connected to the external port 160 .

[0039] The grounding module 101 is connected to the external port 160, so that the chuck 100 can also be grounded. In the subsequent testing of the IGBT wafer, the IGBT wafer placed on the chuck 100 can be grounded, reducing the probability of leakage current in the IGBT wafer, thereby improving the accuracy of the test results.

[0040] During the testing of the IGBT wafer, the probe card 102 is used to test the IGBT wafer carried on the chuck 100. Compared with the solution of cutting the IGBT wafer into a single IGBT and then testing the single IGBT, the embodiment of the present invention directly tests the IGBT wafer, that is, directly performs wafer-level testing, thereby improving the testing efficiency of the IGBT wafer.

[0041] In this embodiment, the probe card 102 includes a fixed needle ring 110 and a plurality of protruding probes (not marked) fixed on the fixed needle ring 110 .

[0042] The needle fixing ring 110 is used to fix the positions of several probes to reduce the risk of the probes falling off.

[0043] like Figure 2 As shown, during the testing of the IGBT wafer, the IGBT wafer includes a front side (not marked) and a back side (not marked) opposite thereto, a gate 130 and an emitter 132 located on the side of the gate 130 are formed on the front side of the IGBT wafer, an isolation structure 131 is formed between the gate 130 and the emitter 132, and a collector 136 is formed on the back side of the IGBT wafer.

[0044] To this end, during the test of the IGBT wafer, the insulating probe 106 is in contact with the isolation structure 131. The insulating probe 106 has an insulating effect, which reduces the risk of leakage between the emitter 132 and the gate 130 through the insulating probe 106, and also reduces the probability of leakage current in the IGBT wafer, thereby improving the accuracy of the test results and further improving the reliability of the IGBT wafer.

[0045] As an example, the insulating probe 106 includes a metal probe 112 and an insulating layer 113 covering the metal probe 112 .

[0046] It should be noted that, by providing the insulating layer 113 covering the metal probe 112 , the insulating layer 113 reduces the risk of leakage between the emitter 132 and the gate 130 through the insulating probe 106 .

[0047] In this embodiment, the material of the insulating layer 113 includes epoxy resin.

[0048] It should be noted that epoxy resin can withstand a relatively large temperature range and can meet various temperatures for IGBT wafer testing. At the same time, epoxy resin has high safety performance and has little impact on the chuck 100 and the IGBT wafer subsequently placed on the chuck 100.

[0049] As an example, the temperature range that the insulated probe 106 can withstand is -50°C to 180°C.

[0050] It should also be noted that epoxy resin has the characteristic of being easy to remove. After testing the IGBT wafer, the metal probe 112 in the insulating probe 106 can be exposed by removing the epoxy resin, so that other wafer-level tests can be performed using the exposed metal probe 112 in the insulating probe 106, thereby improving the reusability of the insulating probe 106 and reducing production costs.

[0051] As an example, the epoxy resin is removed by using isopropyl alcohol (IPA).

[0052] In this embodiment, the probe card 102 has a measurement area 100A and an isolation area 100B located between adjacent measurement areas 100A.

[0053] The measurement area 100A is used to set the measurement probes 108 , and the probes in the measurement area 100A are used to test the IGBT wafer. Specifically, the probes in the measurement area 100A are used to test the gate 130 and the emitter 132 of the IGBT wafer.

[0054] The insulating region 100B is used to set the insulating probe 106. The insulating probe 106 has an insulating effect, which reduces the risk of leakage between the emitter 132 and the gate 130 through the insulating probe 106, and thus reduces the probability of leakage current in the IGBT wafer, thereby improving the accuracy of the test results and further improving the reliability of the IGBT wafer.

[0055] As an example, the insulating probe 106 is located in the insulating region 100B.

[0056] In this embodiment, the probe card 102 further includes a measurement probe 108 . The measurement probe 108 is located in the measurement area 100A and is used to test the IGBT wafer.

[0057] Specifically, during the test of the IGBT wafer, the measuring probe 108 contacts the gate 130 and the emitter 132 , and the measuring probe 108 applies a voltage value to the gate 130 and the emitter 132 to characterize the gate 130 breakdown voltage test of the IGBT wafer, thereby further improving the reliability of the IGBT wafer.

[0058] Correspondingly, the present invention also provides a testing method. Figure 3 It is a flow chart of the steps of an embodiment of the testing method of the present invention.

[0059] In this embodiment, the detection method includes the following basic steps:

[0060] Step S1: providing the testing device of the above embodiment;

[0061] Step S2: placing an IGBT wafer on the chuck of the testing device;

[0062] Step S3: grounding the chuck;

[0063] Step S4: moving the probe card to contact the probe card with the IGBT wafer, and using the probe card to test the IGBT wafer to determine the reliability of the IGBT wafer.

[0064] In the testing method provided by the embodiment of the present invention, an IGBT wafer is placed on the chuck of the testing device, the chuck is grounded, the probe card is in contact with the IGBT wafer, and the probe card is used to test the IGBT wafer. Compared with the solution of cutting the IGBT wafer to form a single IGBT and then testing the single IGBT, the embodiment of the present invention directly tests the IGBT wafer, that is, directly performs wafer-level testing, thereby improving the testing efficiency of the IGBT wafer. At the same time, by grounding the chuck carrying the IGBT wafer and using a probe card with insulating probes to test the IGBT wafer, the probability of leakage current generated by the IGBT wafer during the test process can be reduced, the accuracy of the test results is improved, and the reliability of the IGBT wafer can be further improved.

[0065] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and easy to understand, the following is a summary of the present invention. Figures 1 to 3 The specific embodiments of the present invention are described in detail.

[0066] refer to Figure 3 , execute step S1: provide the testing device of the aforementioned embodiment of the invention.

[0067] For the description of the testing device, please refer to the detailed description of the aforementioned embodiment of the invention, which will not be repeated here.

[0068] As an example, an IGBT wafer includes a front side and a back side opposite thereto, a gate and an emitter located on the side of the gate are formed on the front side of the IGBT wafer, an isolation structure is formed between the gate and the emitter, and a collector is formed on the back side of the IGBT wafer.

[0069] To this end, during the testing of the IGBT wafer, the insulating probe provided subsequently contacts the isolation structure. The insulating probe has an insulating effect, which reduces the risk of leakage between the emitter and the gate through the insulating probe, and thus reduces the probability of leakage current in the IGBT wafer, thereby improving the accuracy of the test results and further improving the reliability of the IGBT wafer.

[0070] refer to Figure 3 , executing step S2: placing an IGBT wafer on the chuck of the testing device.

[0071] Specifically, an IGBT wafer is placed on the chuck of the test device, so that a probe card provided subsequently can perform wafer-level testing on the IGBT wafer, thereby improving the testing efficiency of the IGBT wafer.

[0072] In this embodiment, the step of placing the IGBT wafer on the chuck of the testing device includes: placing the IGBT wafer on the chuck with the collector of the IGBT wafer facing the chuck.

[0073] It should be noted that after the chuck is grounded, the IGBT wafer placed on the chuck can also be grounded, which means that the collector in the IGBT wafer is grounded, reducing the probability of leakage current in the IGBT wafer, thereby improving the accuracy of the test results, and further improving the reliability of the IGBT wafer.

[0074] refer to Figure 3 , execute step S3: ground the chuck.

[0075] Specifically, the IGBT wafer placed on the chuck is grounded, which means that the collector in the IGBT wafer is grounded, thereby reducing the probability of leakage current in the IGBT wafer.

[0076] As an example, the step of grounding the chuck includes: grounding the chuck through a grounding module in a testing device.

[0077] As an example, the grounding module includes a grounding algorithm submodule, and the grounding algorithm submodule is used to ground the grounding module.

[0078] The grounding algorithm submodule has a program for setting the grounding module to be grounded. The program can realize the grounding of the grounding module, thereby grounding the chuck.

[0079] refer to Figure 3 , executing step S4: moving the probe card, bringing the probe card into contact with the IGBT wafer, and using the probe card to test the IGBT wafer to determine the reliability of the IGBT wafer.

[0080] Specifically, during the testing of the IGBT wafer, the probe card is used to test the IGBT wafer carried on the chuck. Compared with the solution of cutting the IGBT wafer into a single IGBT and then testing the single IGBT, this embodiment directly tests the IGBT wafer, that is, directly performs wafer-level testing, thereby improving the testing efficiency of the IGBT wafer.

[0081] In this embodiment, the probe card includes a fixed needle ring and a plurality of protruding probes fixed on the fixed needle ring.

[0082] The needle fixing ring is used to fix the positions of several probes to reduce the risk of the probes falling off.

[0083] As an example, the insulating probe includes a metal probe and an insulating layer covering the metal probe.

[0084] It should be noted that, by providing an insulating layer covering the metal probe, the insulating layer reduces the risk of leakage between the emitter and the gate through the insulating probe.

[0085] In this embodiment, the material of the insulating layer includes epoxy resin.

[0086] It should be noted that epoxy resin can withstand a relatively large temperature range and can meet various temperatures for IGBT wafer testing. At the same time, epoxy resin has high safety performance and has little impact on the chuck and the IGBT wafer subsequently placed on the chuck.

[0087] As an example, the insulated probe can withstand a temperature range of -50°C to 180°C.

[0088] It should also be noted that epoxy resin has the characteristic of being easy to remove. After testing the IGBT wafer, the metal probes in the insulating probe can be exposed by removing the epoxy resin, so that other wafer-level tests can be performed using the exposed metal probes in the insulating probe, thereby improving the performance of the insulating probe reuse and reducing production costs.

[0089] As an example, the epoxy resin is removed by using isopropyl alcohol (IPA).

[0090] In this embodiment, the probe card has a measuring area and an insulating area between adjacent measuring areas.

[0091] The measurement area is used to set measurement probes, and the probes in the measurement area are used to test the IGBT wafer. Specifically, the probes in the measurement area are used to test the gate and emitter of the IGBT wafer.

[0092] The insulating area is used to set up insulating probes. The insulating probes have an insulating effect, which reduces the risk of leakage between the emitter and the gate through the insulating probes, and also reduces the probability of leakage current in the IGBT wafer, thereby improving the accuracy of the test results and further improving the reliability of the IGBT wafer.

[0093] As an example, the insulating probe is located in the insulating area.

[0094] In this embodiment, the probe card further includes: a measuring probe, which is located in the measuring area and is used to test the IGBT wafer.

[0095] Specifically, during the test of the IGBT wafer, the measuring probe contacts the gate and the emitter, and the voltage value is applied to the gate and the emitter by the measuring probe to characterize the gate breakdown voltage test of the IGBT wafer, thereby further improving the reliability of the IGBT wafer.

[0096] In this embodiment, the steps of using the probe card to test the IGBT wafer include: selecting any area to be tested on the IGBT wafer; moving the probe card above the area to be tested; contacting the measuring probe with the gate and the emitter, and contacting the insulating probe with the isolation structure; applying a voltage value to the gate, and grounding the emitter.

[0097] Specifically, the area to be tested is used as a sample area of ​​the IGBT wafer. By testing the sample area, the reliability of the IGBT wafer can be reflected.

[0098] As an example, the area of ​​the test area is greater than or equal to 10CM 2 .

[0099] In this embodiment, the step of judging the reliability of the IGBT wafer includes: measuring the actual leakage current value between the gate and the emitter in the IGBT wafer; comparing the actual leakage current value with the ideal leakage current value of the IGBT wafer, when the actual leakage current value is greater than or equal to the ideal leakage current value, the reliability of the IGBT wafer is poor, and when the actual leakage current value is less than the ideal leakage current value, the reliability of the IGBT wafer is good.

[0100] Specifically, the ideal leakage current value is 100 nA.

[0101] It should be noted that, during the process of using the probe card to test the IGBT wafer, when the actual leakage current value is equal to the ideal leakage current value, the voltage value applied to the gate at this time is the gate breakdown voltage.

[0102] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A testing device, which is used to test an IGBT wafer, characterized in that: include: A chuck for holding the IGBT wafer; A grounding module, connected to the chuck, and used for grounding the chuck; A probe card is suspended above the chuck, and the probe card is used to test the IGBT wafer. The probe card has insulating probes.

2. The testing device according to claim 1, characterized in that: The chuck has an external connection port; The grounding module is connected to the external port.

3. The testing device according to claim 1, characterized in that: The grounding module has a grounding algorithm submodule, and the grounding algorithm submodule is used to ground the grounding module.

4. The testing device according to claim 1, characterized in that: The probe card has a measuring area and an insulating area between adjacent measuring areas; The insulating probe is located in the insulating area; The probe card further includes a measuring probe, which is located in the measuring area and is used to test the IGBT wafer.

5. The testing device according to claim 1 or 4, characterized in that: The insulating probe comprises a metal probe and an insulating layer covering the metal probe.

6. The testing device according to claim 5, characterized in that: The material of the insulating layer includes epoxy resin.

7. A testing method, characterized in that: include: Providing a testing device as claimed in any one of claims 1 to 6; Placing an IGBT wafer on a chuck of the testing device; grounding the chuck; The probe card is moved to contact the probe card with the IGBT wafer, and the IGBT wafer is tested using the probe card to determine the reliability of the IGBT wafer.

8. The testing method according to claim 7, characterized in that: In the step of placing the IGBT wafer, the IGBT wafer includes a front side and a back side opposite thereto, a gate and an emitter located on the side of the gate are formed on the front side of the IGBT wafer, an isolation structure is formed between the gate and the emitter, and a collector is formed on the back side of the IGBT wafer.

9. The testing method according to claim 8, characterized in that: The step of placing the IGBT wafer on the chuck of the testing device includes: placing the collector of the IGBT wafer toward the chuck and placing the IGBT wafer on the chuck.

10. The testing method according to claim 7, characterized in that: The probe card has a measuring area and an insulating area between adjacent measuring areas; The insulating probe is located in the insulating area; The probe card further includes a measuring probe, which is located in the measuring area and is used to test the IGBT wafer.

11. The testing method according to claim 10, characterized in that: In the step of placing the IGBT wafer, the IGBT wafer includes a front side and a back side opposite thereto, a gate and an emitter located at a side of the gate are formed on the front side of the IGBT wafer, an isolation structure is formed between the gate and the emitter, and a collector is formed on the back side of the IGBT wafer; The steps of using the probe card to test the IGBT wafer include: selecting any area to be tested on the IGBT wafer; moving the probe card above the area to be tested; contacting the measuring probe with the gate and emitter, and contacting the insulating probe with the isolation structure; applying voltage to the gate, and grounding the emitter.

12. The testing method according to claim 11, characterized in that: The area of ​​the test area is greater than or equal to 10CM 2 .

13. The testing method according to claim 11, characterized in that: The steps of judging the reliability of the IGBT wafer include: measuring the actual leakage current value between the gate and the emitter in the IGBT wafer; comparing the actual leakage current value with the ideal leakage current value of the IGBT wafer, when the actual leakage current value is greater than the ideal leakage current value, the reliability of the IGBT wafer is poor, and when the actual leakage current value is less than the ideal leakage current value, the reliability of the IGBT wafer is good.

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