Silicon carbide device testing method and system and storage medium

Abstract

The invention provides a silicon carbide device test method and system and a storage medium, and the method comprises the steps: obtaining a test signal, and generating a heating signal based on the test signal to supply a constant current to a silicon carbide device to heat the silicon carbide device; obtaining the heating temperature of the silicon carbide device, judging whether the heating temperature reaches a preset temperature or not, if yes, generating a turn-off signal, and stopping constant current supply to the silicon carbide device, cooling the silicon carbide device and reverse current supply to the silicon carbide device based on the turn-off signal. Acquiring a first test parameter of the silicon carbide device when reverse current is started and a second test parameter of the silicon carbide device when reverse current is ended; whether the silicon carbide device needs to be tested or not is judged, and if yes, a heating signal continues to be generated based on the test signal; and if not, generating an end signal to stop testing the silicon carbide device. According to the invention, the power cycle test can be effectively and reliably carried out on silicon carbide devices such as MOS tubes.

Description

Technical Field

[0001] The present application relates to the field of silicon carbide technology, and in particular to a silicon carbide device testing method, system and storage medium. Background Art

[0002] Silicon carbide devices are high-performance semiconductor devices made of silicon carbide materials. They are widely classified, including diodes, transistors, power modules and other types. With their unique performance advantages, silicon carbide devices play an important role in power electronics, automotive electronics, optoelectronics, new energy and other fields. In order to enable silicon carbide devices to continue to work in the field of application, it is necessary to clarify the power of silicon carbide devices, that is, to perform power cycle tests on silicon carbide devices.

[0003] However, at present, only silicon devices are cycle tested, that is, constant current heating is usually performed first, and then air cooling is performed to test the reliability of silicon devices. Constant current heating and related parameter tests are achieved through parasitic diodes. First, a large current is passed to achieve heating, and then a small current is passed to obtain parameters. Then, for the silicon carbide type devices that are currently being tested, since silicon carbide devices have a relatively high reliability to heat, if the current method is still used, it will not be possible to perform a more effective reliability test on silicon carbide type devices. Summary of the invention

[0004] In order to effectively and reliably perform power cycle testing on silicon carbide devices such as MOS tubes, the embodiments of the present application provide a silicon carbide device testing method, system and storage medium.

[0005] In a first aspect, this embodiment provides a method for testing a silicon carbide device, the method comprising: Acquire a test signal, and generate a heating signal based on the test signal to pass a constant current to the silicon carbide device to heat the silicon carbide device; Obtaining a heating temperature of the silicon carbide device, determining whether the heating temperature reaches a preset temperature, and generating a shutdown signal if the temperature reaches a preset temperature, stopping passing a constant current to the silicon carbide device, cooling the silicon carbide device, and passing a reverse current to the silicon carbide device based on the shutdown signal, and obtaining a first test parameter of the silicon carbide device when the reverse current starts to be passed and a second test parameter when the reverse current ends; Determine whether the silicon carbide device needs to be tested, and if necessary, continue to generate a heating signal based on the test signal; If not required, an end signal is generated to stop testing the silicon carbide device.

[0006] In some embodiments, the silicon carbide device includes a drain and a source, and obtaining the heating temperature of the silicon carbide device includes: A heating voltage value between the source and the drain is obtained, and the heating voltage value is substituted into a preset voltage-temperature correspondence relationship to obtain a heating temperature of the silicon carbide device.

[0007] In some embodiments, the silicon carbide device further includes a gate, and stopping passing a constant current to the silicon carbide device, cooling the silicon carbide device, and passing a reverse current to the silicon carbide device based on the shutdown signal includes: Based on the shutdown signal, applying a shutdown voltage to the gate of the silicon carbide device to shut down the silicon carbide device to stop passing a constant current to the silicon carbide device; Based on the shutdown signal, a cooling device is started to cool the silicon carbide device so that the temperature of the silicon carbide device is maintained at a preset temperature within a preset cooling time; And based on the shutdown signal, the reverse input circuit is started to work, so that the reverse input circuit passes reverse current to the silicon carbide device within the preset cooling time.

[0008] In some embodiments, generating a heating signal based on the test signal to pass a constant current to the silicon carbide device to heat the silicon carbide device includes: Applying the test signal to a device connected to a gate to generate a heating signal indicating that a heating operation needs to be performed on the silicon carbide device; The heating signal is sent to the gate of the silicon carbide device, and the constant current source connected to the drain of the silicon carbide device is controlled to operate, so as to pass a constant current to the silicon carbide device to heat the silicon carbide device.

[0009] In some embodiments, the method further comprises: If the heating temperature does not reach the preset temperature, continue to pass a constant current through the silicon carbide device to heat the silicon carbide device.

[0010] In a second aspect, this embodiment provides a silicon carbide device testing system, the system comprising: a heating module, a control module and a testing module; wherein: The heating module is used to obtain a test signal, and generate a heating signal based on the test signal to pass a constant current to the silicon carbide device to heat the silicon carbide device; The control module is used to obtain the heating temperature of the silicon carbide device, determine whether the heating temperature reaches a preset temperature, and generate a shutdown signal if the temperature reaches a preset temperature; The test module is used to stop passing a constant current to the silicon carbide device, cool the silicon carbide device, and pass a reverse current to the silicon carbide device based on the shutdown signal, and obtain a first test parameter of the silicon carbide device when starting to pass the reverse current and a second test parameter when ending to pass the reverse current; The control module is also used to determine whether the silicon carbide device needs to be tested. If not, an end signal is generated to stop testing the silicon carbide device. The heating module is further used to continue to generate a heating signal based on the test signal if the silicon carbide device needs to be tested.

[0011] In some embodiments, the heating module includes: a conduction circuit and an operational amplifier circuit; wherein, The input end of the conduction circuit is used to receive a test signal, so that after receiving the test signal, a positive voltage is output through the output end of the conduction circuit; The positive input terminal of the operational amplifier circuit is connected to the output terminal of the conduction circuit, and is used to receive the positive voltage, so as to output a heating signal through the output terminal of the operational amplifier circuit; The gate of the silicon carbide device is connected to the output end of the operational amplifier circuit, the drain of the silicon carbide device is connected to a constant current source, and the silicon carbide device is used to receive the heating signal to turn on the silicon carbide device to pass a constant current to the silicon carbide device to heat the silicon carbide device.

[0012] In some embodiments, the test module includes: an input circuit and a cooling circuit; wherein, The input end of the conduction circuit is used to receive a shutdown signal, so that after receiving the shutdown signal, a shutdown negative voltage is output through the output end of the conduction circuit; The operational amplifier circuit is used to receive the shutdown negative voltage to output a temperature reduction signal through the output terminal of the operational amplifier circuit; The silicon carbide device is used to receive the temperature reduction signal to turn off the silicon carbide device to stop passing a constant current to the silicon carbide device; and the input end of the input circuit is used to receive the shutdown signal, so that after receiving the shutdown signal, a reverse current is output through the output end of the input circuit; The source of the silicon carbide device is connected to the output end of the input circuit to pass a reverse current to the silicon carbide device; The temperature reduction circuit is used to receive the temperature reduction signal to start the temperature reduction circuit to cool the silicon carbide device, so that the temperature of the silicon carbide device is maintained at a preset temperature within a preset temperature reduction time.

[0013] In some of the embodiments, the system further comprises a shell temperature detection module; wherein, The shell temperature detection module is used to detect the shell temperature of the silicon carbide device, and during the heating process of the silicon carbide device, sends the shell temperature to the control module so that the control module obtains the heating temperature of the silicon carbide device.

[0014] In a third aspect, this embodiment provides a computer-readable storage medium on which a computer program that can be run on a processor is stored. When the computer program is executed by the processor, a silicon carbide device testing method as described in the first aspect is implemented.

[0015] By adopting the above method, the present application first obtains a test signal, generates a heating signal based on the test signal to pass a constant current to the silicon carbide device to heat the silicon carbide device. Then obtain the heating temperature of the silicon carbide device, determine whether the heating temperature reaches the preset temperature, and if so, generate a shutdown signal, stop passing a constant current to the silicon carbide device, cool the silicon carbide device, and pass a reverse current to the silicon carbide device based on the shutdown signal, and obtain the first test parameter of the silicon carbide device when the reverse current starts and the second test parameter when the reverse current ends. Then determine whether the silicon carbide device still needs to be tested. If necessary, continue to generate a heating signal based on the test signal; if not, generate an end signal to stop testing the silicon carbide device. In this way, the silicon carbide device is directly acted on during the heating process, and the parasitic diode is directly acted on during the cooling test process, rather than directly acting on the parasitic diode throughout the entire process, so that the silicon carbide device can make corresponding changes more intuitively and obviously, so that power cycle tests can be effectively and reliably performed on silicon carbide devices such as MOS tubes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the principle of testing a silicon carbide device provided in an embodiment of the present application.

[0017] Figure 2 This is a block diagram of a silicon carbide device testing method provided in an embodiment of the present application.

[0018] Figure 3 This is a framework diagram of a silicon carbide device testing system provided in an embodiment of the present application.

[0019] Figure 4 It is a schematic diagram of the heating operation of a silicon carbide device provided in an embodiment of the present application.

[0020] Figure 5 It is a schematic diagram of measuring work for testing silicon carbide devices provided in an embodiment of the present application.

[0021] Reference numerals: 1. Heating module; 11. Conducting circuit; 12. Operational amplifier circuit; 2. Control module; 3. Testing module; 31. Input circuit; 32. Cooling circuit. DETAILED DESCRIPTION

[0022] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. However, it should be understood by those of ordinary skill in the art that the present application can be implemented without these details. For those of ordinary skill in the art, it is obvious that various changes can be made to the embodiments disclosed in the present application, and without departing from the principles and scope of the present application, the general principles defined in the present application can be applied to other embodiments and application scenarios. Therefore, the present application is not limited to the embodiments shown, but conforms to the broadest scope consistent with the scope claimed for protection in the present application.

[0023] The embodiments of the present application are further described in detail below in conjunction with the drawings in the specification.

[0024] Figure 1 Schematic diagram of the principle of testing silicon carbide devices provided in the embodiment of the present application. Figure 1 As shown, the controller is connected to the conduction circuit 11, the conduction circuit 11 is connected to the positive input terminal + of the amplifier A through the first resistor R1, the output terminal of the amplifier A is connected to the gate G of the silicon carbide device through the second resistor R2, and the negative input terminal - of the amplifier A is connected to the output terminal of the amplifier A through the capacitor C. The drain D of the silicon carbide device is connected to the controller through the first constant current source A1. The source S of the silicon carbide device is connected to the same potential through the third resistor R3, and the negative input terminal - of the amplifier A is connected to the source S of the silicon carbide device through the fourth resistor R4. The drain D of the silicon carbide device is also connected to a negative voltage through a test switch K controlled by the controller.

[0025] When the control end outputs an instruction for heating operation, a positive voltage is input to the positive input end of the op amp A, and a constant current is applied through A1, the silicon carbide device is turned on, and the silicon carbide device can be heated at this time. When the control end outputs an instruction for testing operation, A1 does not work and closes the test switch K, a negative voltage is input to the positive input end of the op amp A, the op amp A is in a follow state, and the silicon carbide device is turned off. At this time, the controller closes the test switch K to apply a reverse current to the silicon carbide device, and the silicon carbide device is cooled down. The relevant test parameters are obtained by testing the silicon carbide device, thereby completing a power test. Then continue to perform the above operation to perform a cycle test of the power of the silicon carbide device, and stop the above operation until the test is completed. In this way, the silicon carbide device is directly acted on during the heating process, and the parasitic diode is directly acted on during the cooling test process, rather than directly acting on the parasitic diode during the entire process, so that the silicon carbide device can make corresponding changes more intuitively and obviously, so that the power cycle test of silicon carbide devices such as MOS tubes can be effectively and reliably performed.

[0026] Figure 2 1 is a block diagram of a silicon carbide device testing method provided in an embodiment of the present application. Figure 2 As shown, a method for testing a silicon carbide device comprises the following steps: Step S100 , obtaining a test signal, and generating a heating signal based on the test signal to pass a constant current to the silicon carbide device to heat the silicon carbide device.

[0027] This embodiment describes the method for testing silicon carbide devices from the perspective of a device for testing silicon carbide devices. A controller is provided in the device, which receives all information generated in the device. The above-mentioned test signal represents an instruction for testing the silicon carbide device. The test signal can be specifically sent by relevant personnel, or it can be generated by the device itself after the device is powered on. If the test signal is sent by relevant personnel, then the device is already powered on at this time, and when there is a test requirement, it is sent by relevant personnel so that the device can obtain the detection signal. If the test signal is generated by the device itself, then the detection signal can be directly generated at the moment the device is powered on, or the test signal can be generated after a preset time, so that after the device obtains the test signal, it can know that the silicon carbide device needs to be tested. This embodiment does not further limit how to obtain the test signal.

[0028] The step of generating a heating signal based on the test signal to heat the silicon carbide device by passing a constant current to the silicon carbide device comprises the following steps: Step S101 : applying a test signal to a device connected to a gate to generate a heating signal indicating that a heating operation needs to be performed on the silicon carbide device.

[0029] Step S102, sending a heating signal to the gate of the silicon carbide device, and controlling the constant current source connected to the drain of the silicon carbide device to operate, so as to pass a constant current to the silicon carbide device to heat the silicon carbide device.

[0030] The devices connected to the gate are the controller, the conduction circuit 11 and the amplifier A. The test signal is sent to Figure 1 The controller in the circuit 11 is used to make the controller output an instruction for heating operation, and the instruction is sent to the conduction circuit 11, so that the conduction circuit 11 outputs a positive voltage, and the positive input terminal of the op amp A receives the positive voltage, and the op amp A outputs a heating signal through its output terminal. Then the heating signal acts on the gate G of the silicon carbide device, and the heating signal is sent to the controller, so that the controller controls the first constant current source A1 connected to the drain D of the silicon carbide device to work through the heating signal, and passes a constant current to the silicon carbide device to make the silicon carbide device conductive, that is, the silicon carbide device is heated by passing a constant current to the silicon carbide device. In this way, the heating work directly acts on the silicon carbide device itself, which can make the silicon carbide device more intuitive and obvious to make corresponding changes, and provide a better state for subsequent testing work.

[0031] Step S200, obtaining the heating temperature of the silicon carbide device, determining whether the heating temperature reaches a preset temperature, and generating a shutdown signal if the temperature reaches a preset temperature, and based on the shutdown signal, stopping the constant current from flowing to the silicon carbide device, cooling the silicon carbide device, and flowing a reverse current to the silicon carbide device, and obtaining a first test parameter of the silicon carbide device when starting to flow the reverse current and a second test parameter when ending to flow the reverse current.

[0032] This embodiment is described by taking the silicon carbide device as an n-type MOS tube as an example. The silicon carbide device includes a drain electrode D, a gate electrode G and a source electrode S.

[0033] Wherein, obtaining the heating temperature of the silicon carbide device includes: obtaining a heating voltage value between a source and a drain, and substituting the heating voltage value into a preset voltage-temperature correspondence relationship to obtain the heating temperature of the silicon carbide device.

[0034] When the silicon carbide device is turned on, the heating voltage value between the source and the drain is obtained by testing the voltage value between the source and the drain. A voltage-temperature correspondence is stored in the device, and the voltage-temperature correspondence is obtained in advance through a large number of offline tests. After obtaining the heating voltage value, the heating voltage value is substituted into the preset voltage-temperature correspondence, and the heating temperature of the silicon carbide device can also be obtained. This makes the obtained heating temperature more accurate. After all, the temperature has a certain hysteresis. If the heating temperature is obtained directly by testing the temperature, the obtained heating temperature value will be inaccurate. If the heating voltage value is tested first and then substituted into the corresponding relationship to obtain the heating temperature, the obtained heating temperature will be more accurate. After all, the voltage is real-time and does not have hysteresis.

[0035] The device also stores the maximum temperature required for the cycle test of the silicon carbide device, that is, the preset temperature. By comparing the obtained heating temperature with the preset temperature, if the heating temperature is less than the preset temperature, it indicates that the heating temperature has not reached the preset temperature. If the heating temperature is not less than the preset temperature, it indicates that the heating temperature has reached the preset temperature.

[0036] If the heating temperature does not reach the preset temperature, a constant current continues to be passed to the silicon carbide device to heat the silicon carbide device. That is, the silicon carbide device continues to be in a conducting state, and a constant current is passed to the silicon carbide device to heat the silicon carbide device, and the heating temperature of the silicon carbide device is continuously obtained until the heating temperature reaches the preset temperature, and then the operation of obtaining the heating temperature of the silicon carbide device is stopped.

[0037] If the heating temperature reaches the preset temperature, it indicates that the heating work of the silicon carbide device has been completed. At this time, the silicon carbide device does not need to be heated anymore, and the test parameters of the silicon carbide device need to be obtained. At this time, the controller will generate a shutdown signal, thereby stopping the constant current from being passed to the silicon carbide device based on the shutdown signal, and passing a reverse current to the silicon carbide device to obtain the first test parameter of the silicon carbide device when the reverse current starts to be passed and the second test parameter when the reverse current ends. Among them, stopping the constant current from being passed to the silicon carbide device, cooling the silicon carbide device, and passing a reverse current to the silicon carbide device based on the shutdown signal includes the following steps: Step S201 : applying a turn-off voltage to the gate of the silicon carbide device based on a turn-off signal, so as to turn off the silicon carbide device and stop passing a constant current to the silicon carbide device.

[0038] Step S202: starting a cooling device based on the shutdown signal to cool the silicon carbide device, so that the temperature of the silicon carbide device is maintained at a preset temperature within a preset cooling time.

[0039] Step S203, and also starting the reverse input circuit based on the shutdown signal, so that the reverse input circuit passes reverse current to the silicon carbide device within a preset cooling time.

[0040] A shutdown signal is sent to the controller, so that the controller outputs an instruction that needs to be measured, and the instruction is sent to the conduction circuit 11, so that the conduction circuit 11 outputs a negative voltage, and a negative voltage is input to the positive input terminal of the operational amplifier A, so that the operational amplifier A is in a following state, and the output terminal of the operational amplifier A outputs a shutdown voltage, so that through the connection between the output terminal of the operational amplifier A and the gate G of the silicon carbide device, the gate of the silicon carbide device is turned on and off, and a shutdown signal is sent to the controller, so that the controller controls the first constant current source A1 connected to the drain D of the silicon carbide device to stop working through the shutdown signal, and stops passing a constant current to the silicon carbide device, so that the silicon carbide device is turned off and not turned on.

[0041] The controller stores a preset cooling time, and the controller also immediately sends the shutdown signal obtained to the cooling device, so that the cooling device starts to start cooling the silicon carbide device, so that the temperature of the silicon carbide device is maintained at the preset temperature within the preset cooling time.

[0042] The controller also controls the shutdown signal to act on the reverse input circuit within the preset cooling time, so that the reverse input circuit starts to work, thereby inputting a reverse current into the source S of the silicon carbide device within the preset cooling time, so that a parasitic diode is generated in the silicon carbide device, and the parasitic diode is turned on, and then the silicon carbide device is measured when the silicon carbide device starts to pass the reverse current and the silicon carbide device is measured when the reverse current ends, so as to obtain the first test parameter and the second test parameter. Among them, the moment when the cooling device is turned on is when the silicon carbide device starts to pass the reverse current, and then the moment after the preset cooling time is when the silicon carbide device ends to pass the reverse current. In this way, the silicon carbide device is directly acted on during the heating process, and the parasitic diode generated in the silicon carbide device is directly acted on during the cooling measurement process, rather than directly acting on the parasitic diode during the entire process, so that the silicon carbide device can make corresponding changes more intuitively and obviously, so that the power cycle test of silicon carbide devices such as MOS tubes can be effectively and reliably performed.

[0043] Step S300, determining whether the silicon carbide device needs to be tested further, and if so, continuing to generate a heating signal based on the test signal.

[0044] Step S400: if not necessary, generate an end signal to stop testing the silicon carbide device.

[0045] The device stores the set number of cycles required for testing the silicon carbide device. Each time a test parameter is obtained, the actual number of cycles currently required for testing the silicon carbide device is updated. The device determines whether the silicon carbide device needs to be tested by comparing the actual number to the set number. If the actual number is equal to the set number, the silicon carbide device does not need to be tested; if the actual number is not equal to the set number, the silicon carbide device needs to be tested.

[0046] In addition, during the test of silicon carbide devices, if a stop command is received from a staff member, it is no longer necessary to compare whether the actual number of times is equal to the set number of times to determine whether the silicon carbide device needs to be tested, but directly determines that the silicon carbide device does not need to be tested. This allows staff to control whether testing is still needed based on actual conditions, which is more in line with actual needs.

[0047] When it is determined that the silicon carbide device still needs to be tested, the above step S100 of generating a heating signal based on the test signal to heat the silicon carbide device by passing a constant current through the silicon carbide device, and subsequent steps are repeatedly performed.

[0048] When it is determined that the silicon carbide device no longer needs to be tested, the controller generates an end signal to stop the silicon carbide device from being turned on and to pass reverse current to the silicon carbide device, thereby stopping the test on the silicon carbide device and completing the test of the silicon carbide device. In this way, during the entire cycle test process, the power directly acts on the silicon carbide device during the heating process and directly acts on the parasitic diode during the cooling test, rather than directly acting on the parasitic diode during the entire process, which can make the silicon carbide device more intuitive and obvious to make corresponding changes, and can effectively and reliably perform power cycle tests on silicon carbide devices such as MOS tubes.

[0049] Figure 3 1 is a framework diagram of a silicon carbide device testing system provided in an embodiment of the present application. Figure 3 As shown, a silicon carbide device testing system includes: a heating module 1, a control module 2 and a testing module 3.

[0050] The heating module 1 is used to obtain a test signal, and generate a heating signal based on the test signal to pass a constant current to the silicon carbide device to heat the silicon carbide device.

[0051] The control module 2 is used to obtain the heating temperature of the silicon carbide device and determine whether the heating temperature reaches a preset temperature. If so, a shutdown signal is generated.

[0052] The test module 3 is used to stop passing a constant current to the silicon carbide device, cool the silicon carbide device, and pass a reverse current to the silicon carbide device based on a shutdown signal, and obtain a first test parameter of the silicon carbide device when starting to pass the reverse current and a second test parameter when ending the reverse current.

[0053] The control module 2 is also used to determine whether the silicon carbide device needs to be tested. If not, an end signal is generated to stop testing the silicon carbide device.

[0054] The heating module 1 is also used to continue to generate a heating signal based on the test signal if the silicon carbide device needs to be tested.

[0055] The other functions performed by the above-mentioned heating module 1, control module 2 and test module 3 and the technical details of each function are the same as or similar to the corresponding features in the silicon carbide device testing method described above, so they are not repeated here.

[0056] Figure 4 Schematic diagram of heating operation of silicon carbide device provided by the embodiment of the present application. Figure 4 As shown, the heating module 1 includes a conduction circuit 11 and an operational amplifier circuit 12. The input end of the conduction circuit 11 receives a test signal, so that after receiving the test signal, a positive voltage is output through the output end of the conduction circuit. The positive input end of the operational amplifier circuit 12 is connected to the output end of the conduction circuit to receive the positive voltage, so as to output a heating signal through the output end of the operational amplifier circuit 12. The gate G of the silicon carbide device is connected to the output end of the operational amplifier circuit, and the drain D of the silicon carbide device is connected to a constant current source, and the silicon carbide device receives the heating signal to conduct the silicon carbide device to pass a constant current to the silicon carbide device to heat the silicon carbide device.

[0057] Figure 5 Schematic diagram of measuring the silicon carbide device provided in the embodiment of the present application. Figure 5As shown, the test module 3 includes an input circuit 31 and a cooling circuit 32. Among them, the input end of the conduction circuit 11 is used to receive a shutdown signal, so that after receiving the shutdown signal, the shutdown negative voltage is output through the output end of the conduction circuit 11. The operational amplifier circuit 12 receives the shutdown negative voltage to output a cooling signal through the output end of the operational amplifier circuit 12. The silicon carbide device receives the cooling signal to turn off the silicon carbide device to stop passing a constant current to the silicon carbide device, and the input end of the input circuit 31 is used to receive a shutdown signal, so that after receiving the shutdown signal, a reverse current is output through the output end of the input circuit 31. The source S of the silicon carbide device is connected to the output end of the input circuit 31 to pass a reverse current to the silicon carbide device, so that the parasitic diode generated in the silicon carbide device passes a reverse current. In addition, the controller will immediately send the received cooling signal to the cooling circuit 32 to start the cooling circuit 32 to cool the silicon carbide device, so that the temperature of the silicon carbide device is maintained at a preset temperature within a preset cooling time. In this way, the power directly acts on the silicon carbide device during the heating process and directly acts on the parasitic diode generated in the silicon carbide device during the cooling measurement process, rather than directly acting on the parasitic diode during the entire process. This can make the silicon carbide device make corresponding changes more intuitively and obviously, thereby effectively and reliably performing power cycle tests on silicon carbide devices such as MOS tubes.

[0058] In addition, the system also includes a shell temperature detection module and a temperature detection module. The shell temperature detection module is used to detect the shell temperature of the silicon carbide device, and the temperature detection module is used to detect the junction temperature of the parasitic diode generated by the silicon carbide device. The shell temperature and junction temperature are sent to the control module so that the control module obtains the shell temperature and junction temperature, thereby obtaining the temperature difference between the shell temperature and the junction temperature as a measurement parameter.

[0059] An embodiment of the present application further provides a computer storage medium on which a computer program is stored. When the computer program is run on a computer, the computer can execute the steps in the silicon carbide device testing method described above.

[0060] It should be understood that, although the steps in the flowchart of the accompanying drawings are shown in sequence according to the instructions of the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless explicitly stated in this document, the execution of these steps is not strictly limited in order and can be performed in other orders.

[0061] The above description is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for testing a silicon carbide device, characterized in that: The method comprises: Acquire a test signal, and generate a heating signal based on the test signal to pass a constant current to the silicon carbide device to heat the silicon carbide device; Obtaining a heating temperature of the silicon carbide device, determining whether the heating temperature reaches a preset temperature, and generating a shutdown signal if the temperature reaches a preset temperature, stopping passing a constant current to the silicon carbide device, cooling the silicon carbide device, and passing a reverse current to the silicon carbide device based on the shutdown signal, and obtaining a first test parameter of the silicon carbide device when the reverse current starts to be passed and a second test parameter when the reverse current ends; Determine whether the silicon carbide device needs to be tested, and if necessary, continue to generate a heating signal based on the test signal; If not required, an end signal is generated to stop testing the silicon carbide device.

2. The method according to claim 1, characterized in that: The silicon carbide device includes a drain and a source, and obtaining the heating temperature of the silicon carbide device includes: A heating voltage value between the source and the drain is obtained, and the heating voltage value is substituted into a preset voltage-temperature correspondence relationship to obtain a heating temperature of the silicon carbide device.

3. The method according to claim 1, characterized in that The silicon carbide device further includes a gate, and the steps of stopping passing a constant current to the silicon carbide device, cooling the silicon carbide device, and passing a reverse current to the silicon carbide device based on the shutdown signal include: Applying a turn-off voltage to the gate of the silicon carbide device based on the turn-off signal to turn off the silicon carbide device to stop passing a constant current to the silicon carbide device; Based on the shutdown signal, a cooling device is started to cool the silicon carbide device so that the temperature of the silicon carbide device is maintained at a preset temperature within a preset cooling time; And based on the shutdown signal, the reverse input circuit is started to work, so that the reverse input circuit passes reverse current to the silicon carbide device within the preset cooling time.

4. The method according to claim 1, characterized in that: The step of generating a heating signal based on the test signal to pass a constant current to the silicon carbide device to heat the silicon carbide device comprises: Applying the test signal to a device connected to a gate to generate a heating signal indicating that a heating operation needs to be performed on the silicon carbide device; The heating signal is sent to the gate of the silicon carbide device, and the constant current source connected to the drain of the silicon carbide device is controlled to operate, so as to pass a constant current to the silicon carbide device to heat the silicon carbide device.

5. The method according to claim 1, characterized in that The method further comprises: If the heating temperature does not reach the preset temperature, continue to pass a constant current through the silicon carbide device to heat the silicon carbide device.

6. A silicon carbide device testing system, characterized in that: The system comprises: a heating module, a control module and a testing module; wherein, The heating module is used to obtain a test signal, and generate a heating signal based on the test signal to pass a constant current to the silicon carbide device to heat the silicon carbide device; The control module is used to obtain the heating temperature of the silicon carbide device, determine whether the heating temperature reaches a preset temperature, and generate a shutdown signal if the temperature reaches a preset temperature; The test module is used to stop passing a constant current to the silicon carbide device, cool the silicon carbide device, and pass a reverse current to the silicon carbide device based on the shutdown signal, and obtain a first test parameter of the silicon carbide device when starting to pass the reverse current and a second test parameter when ending to pass the reverse current; The control module is also used to determine whether the silicon carbide device needs to be tested. If not, an end signal is generated to stop testing the silicon carbide device. The heating module is further used to continue to generate a heating signal based on the test signal if the silicon carbide device needs to be tested.

7. The system according to claim 6, characterized in that The heating module comprises: a conduction circuit and an operational amplifier circuit; wherein, The input end of the conduction circuit is used to receive a test signal, so that after receiving the test signal, a positive voltage is output through the output end of the conduction circuit; The positive input terminal of the operational amplifier circuit is connected to the output terminal of the conduction circuit, and is used to receive the positive voltage, so as to output a heating signal through the output terminal of the operational amplifier circuit; The gate of the silicon carbide device is connected to the output end of the operational amplifier circuit, the drain of the silicon carbide device is connected to a constant current source, and the silicon carbide device is used to receive the heating signal to turn on the silicon carbide device to pass a constant current to the silicon carbide device to heat the silicon carbide device.

8. The system according to claim 7, characterized in that The test module includes: an input circuit and a cooling circuit; wherein, The input end of the conduction circuit is used to receive a shutdown signal, so that after receiving the shutdown signal, a shutdown negative voltage is output through the output end of the conduction circuit; The operational amplifier circuit is used to receive the shutdown negative voltage to output a temperature reduction signal through the output terminal of the operational amplifier circuit; The silicon carbide device is used to receive the temperature reduction signal to turn off the silicon carbide device to stop passing a constant current to the silicon carbide device; and the input end of the input circuit is used to receive the shutdown signal, so that after receiving the shutdown signal, a reverse current is output through the output end of the input circuit; The source of the silicon carbide device is connected to the output end of the input circuit to pass a reverse current to the silicon carbide device; The temperature reduction circuit is used to receive the temperature reduction signal to start the temperature reduction circuit to cool the silicon carbide device, so that the temperature of the silicon carbide device is maintained at a preset temperature within a preset temperature reduction time.

9. The system according to claim 7, characterized in that The system also includes a shell temperature detection module; wherein, The shell temperature detection module is used to detect the shell temperature of the silicon carbide device, and during the heating process of the silicon carbide device, sends the shell temperature to the control module so that the control module obtains the heating temperature of the silicon carbide device.

10. A computer-readable storage medium having stored thereon a computer program that can be run on a processor, characterized in that: When the computer program is executed by the processor, a silicon carbide device testing method according to any one of claims 1 to 5 is implemented.

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