Vehicle gauge grade silicon carbide device power cycle test method

Abstract

The invention relates to the field of vehicle-gauge-level silicon carbide device testing, and discloses a vehicle-gauge-level silicon carbide device power cycle testing method, which comprises the following steps: carrying out primary power cycle on a silicon carbide device to be tested, and measuring and recording an initial temperature difference value between a chip center position and an edge position corresponding to a bottom plate of the silicon carbide device when the junction temperature rises to a preset temperature condition; then multiple power cycle tests are carried out, and in each power cycle, when the temperature of the silicon carbide device to be tested rises to a preset temperature condition, the ith power cycle temperature difference value is detected; and calculating the change rate of the temperature difference value, judging the aging condition of the silicon carbide device to be detected and whether the silicon carbide device is invalid, and judging that the device is invalid when the change rate of the temperature difference value exceeds 20-40%. According to the invention, the chip failure and the packaging failure of the device can be monitored in real time at the same time, so that the problem that misjudgment is easily caused because the packaging degradation condition of the power device cannot be accurately reflected by a traditional power cycle test evaluation method is solved, and the test efficiency and reliability are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle - grade silicon carbide device testing, and discloses a power cycle testing method for vehicle - grade silicon carbide devices. Background Art

[0002] With the rapid development of fields such as electric vehicles and smart grids, vehicle - grade silicon carbide (SiC) devices, with their excellent characteristics such as high breakdown electric field and high thermal conductivity, show great application potential. SiC devices can significantly improve system efficiency and reduce equipment volume. Especially in electric vehicles, the application of SiC devices can extend the driving range and contribute to lightweight design. However, SiC devices need to be switched frequently in actual applications and face severe reliability challenges.

[0003] Power cycle testing is an important means to evaluate the reliability of vehicle - grade SiC devices. This test comprehensively evaluates the performance stability and life of the device under long - term and high - load conditions by simulating the power changes during the operation of electric vehicles, ensuring the selection of SiC devices with excellent performance, thus guaranteeing the safety and stability of electric vehicles and promoting the sustainable development of the electric vehicle industry.

[0004] After retrieval, a Chinese patent with publication number CN119178981A, a power cycle testing method for power devices, includes: performing an initial detection on the power device to be tested to obtain an initial threshold voltage, and performing a power cycle test on the power device to be tested; when the power device to be tested is turned off and the junction temperature of the power device to be tested drops to a preset temperature condition during a power cycle, detecting the test threshold voltage of the power device to be tested, calculating the threshold voltage change rate based on the initial threshold voltage and the test threshold voltage, and judging whether the power device to be tested is aged and failed according to the magnitude of the threshold voltage change rate. This method calibrates the characteristic parameters collected during the power cycle in real time, determines whether the chip and package fail according to the parameter offset value, accurately tests the threshold voltage during the power cycle turn - off process, and then calibrates the on - line collected conduction voltage drop to realize the synchronous on - line monitoring of the reliability of silicon carbide chips and packages.

[0005] However, power cycle testing has limitations in evaluating device reliability. It usually can only make a judgment after the device fails and cannot capture the degradation signs of the device during the test in a timely manner. For the case of package aging, it is even more difficult to accurately evaluate this testing method. Because the testing process mainly focuses on power consumption and stability and is difficult to directly judge the degree of aging inside the device. Summary of the Invention

[0006] In view of this, the object of the present invention is to provide a power cycle test method for automotive-grade silicon carbide devices, which can simultaneously monitor the chip failure and package failure of the devices in real time, thereby solving the problems that the traditional power cycle test evaluation method cannot accurately reflect the package degradation of power devices and is prone to misjudgment.

[0007] In order to achieve the above object of the invention, the following technical solutions are further adopted:

[0008] A power cycle test method for automotive-grade silicon carbide devices includes the following steps:

[0009] (1) Perform an initial power cycle on the silicon carbide device to be tested. After the junction temperature rises to the preset temperature condition, use an infrared temperature sensor to measure and record the initial temperature difference between the center position of the chip corresponding to the bottom plate of the silicon carbide device and the edge position of the corresponding chip.

[0010] (2) Perform multiple power cycle tests on the silicon carbide device to be tested. During each power cycle, when the silicon carbide device to be tested rises to the preset temperature condition, detect the temperature difference of the i-th power cycle between the center position of the chip corresponding to the bottom plate of the silicon carbide device and the edge position of the corresponding chip.

[0011] (3) Calculate the temperature difference change rate based on the initial temperature difference and the test temperature difference.

[0012] (4) Judge the aging condition and whether the silicon carbide device to be tested fails according to the magnitude of the temperature difference change rate; when the temperature difference change rate exceeds the preset threshold, it is determined that the silicon carbide device to be tested fails.

[0013] As a further improvement of the present invention, the calculation formula for the initial temperature difference ΔT0 is as follows:

[0014] ΔT0 = T c0 - T e0

[0015] In the formula, T c0 is the temperature at the center position of the chip corresponding to the bottom plate of the initial silicon carbide device, and T e0 is the temperature at the edge position of the chip corresponding to the bottom plate of the initial silicon carbide device.

[0016] As a further improvement of the present invention, the calculation formula for the temperature difference ΔT i of the i-th power cycle is as follows:

[0017] ΔT i = T ci - T ei

[0018] In the formula, T ci is the temperature at the center position of the chip corresponding to the bottom plate of the silicon carbide device in the i-th power cycle, and Tei is the temperature at the edge position of the chip corresponding to the bottom plate of the silicon carbide device during the i-th power cycle.

[0019] As a further improvement of the present invention, the rate of change of the temperature difference ΔT 变化率 is calculated as follows:

[0020] ΔT 变化率 =(ΔT i -ΔT0) / ΔT i ×100%

[0021] In the formula, ΔT i is the temperature difference during the i-th power cycle, and ΔT0 is the initial temperature difference.

[0022] As a further improvement of the present invention, the preset threshold is 20%-40%.

[0023] As a further improvement of the present invention, in step (1), when performing the initial power cycle on the silicon carbide device to be tested, an initial electrical performance test is also included on the silicon carbide device to be tested to exclude initial defective devices.

[0024] As a further improvement of the present invention, the measurement positions of the infrared temperature sensors cover the central area and the edge area of the bottom plate of the silicon carbide device, and its installation method ensures that the temperature data at the central and edge positions can be obtained synchronously.

[0025] As a further improvement of the present invention, the calculation of the rate of change of the temperature difference is performed in real time, and the data is updated after each power cycle.

[0026] The beneficial effects of the present invention are:

[0027] 1. The present invention can simultaneously monitor the chip failure and package failure of the device in real time, thus solving the problems that the traditional power cycle test evaluation method cannot accurately reflect the package degradation of power devices and is prone to misjudgment.

[0028] 2. The present invention can monitor the aging degree of the device in the early stage of the test, timely detect unqualified devices, and effectively reduce the time cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0030] Figure 1 is the flow schematic diagram of the present invention.

[0031] Figure 2 is the structural schematic diagram of the silicon carbide device. Detailed Implementation Manner

[0032] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0033] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0034] As Figure 1-2 shown, the power cycle test method for automotive-grade silicon carbide devices includes the following steps:

[0035] (1) Perform an initial power cycle on the silicon carbide device to be tested. After the junction temperature rises to the preset temperature condition, use an infrared temperature sensor to measure and record the initial temperature difference between the center position of the chip corresponding to the bottom plate of the silicon carbide device and the edge position of the corresponding chip.

[0036] (2) Perform multiple power cycle tests on the silicon carbide device to be tested. During each power cycle, when the silicon carbide device to be tested rises to the preset temperature condition, detect the temperature difference ΔT

[0037] (3) Calculate the temperature difference change rate based on the initial temperature difference and the test temperature difference.

[0038] (4) Judge the aging condition and whether the silicon carbide device to be tested fails according to the magnitude of the temperature difference change rate; when the temperature difference change rate exceeds the preset threshold, it is determined that the silicon carbide device to be tested fails.

[0039] The calculation formula for the initial temperature difference ΔT0 is as follows:

[0040] ΔT0 = T c0 - T e0

[0041] In the formula, T c0 is the temperature at the center position of the chip corresponding to the bottom plate of the initial silicon carbide device, and T e0 is the temperature at the edge position of the chip corresponding to the bottom plate of the initial silicon carbide device.

[0042] The temperature difference ΔT i in the i-th power cycle is calculated as follows:

[0043] ΔTi = T ci -T ei

[0044] Wherein, T ci is the temperature at the center position of the chip corresponding to the bottom plate of the silicon carbide device during the i-th power cycle, and T ei is the temperature at the edge position of the chip corresponding to the bottom plate of the silicon carbide device during the i-th power cycle.

[0045] The rate of change of the temperature difference ΔT 变化率 is calculated as follows:

[0046] ΔT 变化率 =(ΔT i -ΔT0) / ΔT i × 100%

[0047] Wherein, ΔT i is the temperature difference during the i-th power cycle, and ΔT0 is the initial temperature difference.

[0048] The preset threshold is 20% - 40%.

[0049] In step (1), when performing the initial power cycle on the silicon carbide device to be tested, it also includes performing an initial electrical performance test on the silicon carbide device to be tested to exclude initially defective devices.

[0050] The measurement positions of the infrared temperature sensors cover the central area and the edge area of the bottom plate of the silicon carbide device, and their installation methods ensure that the temperature data at the central and edge positions can be obtained synchronously.

[0051] The calculation of the rate of change of the temperature difference is carried out in real time, and the data is updated after each power cycle.

[0052] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, component disassembly or combination, etc., made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A power cycle test method for automotive-grade silicon carbide devices, characterized in that, It includes the following steps: (1) Perform an initial power cycle on the silicon carbide device to be tested. After the junction temperature rises to the preset temperature condition, use an infrared temperature sensor to measure and record the initial temperature difference between the center position and the edge position of the chip corresponding to the bottom plate of the silicon carbide device; (2) Perform multiple power cycle tests on the silicon carbide device to be tested. In each power cycle, when the silicon carbide device to be tested rises to the preset temperature condition, detect the temperature difference of the i-th power cycle between the center position and the edge position of the chip corresponding to the bottom plate of the silicon carbide device in the i-th power cycle; (3) Calculate the temperature difference change rate based on the initial temperature difference and the test temperature difference; (4) Judge the aging condition and whether the silicon carbide device to be tested fails according to the magnitude of the temperature difference change rate; when the temperature difference change rate exceeds the preset threshold, it is determined that the silicon carbide device to be tested fails.

2. The power cycle test method for automotive-grade silicon carbide devices according to claim 1, wherein The calculation formula for the initial temperature difference ΔT0 is as follows: ΔT0 = T c0 - T e0 where T c0 is the temperature at the center position of the chip corresponding to the bottom plate of the initial silicon carbide device, and T e0 is the temperature at the edge position of the chip corresponding to the bottom plate of the initial silicon carbide device.

3. The power cycle test method for automotive-grade silicon carbide devices according to claim 1, characterized in that The temperature difference ΔT in the i-th power cycle i is calculated as follows: ΔT i = T ci - T ei where, T ci is the temperature at the center position of the chip corresponding to the bottom plate of the silicon carbide device in the i-th power cycle, and T ei is the temperature at the edge position of the chip corresponding to the bottom plate of the silicon carbide device in the i-th power cycle.

4. The power cycle test method for automotive-grade silicon carbide devices according to claim 1, characterized in that Rate of change of temperature difference ΔT 变化率 The calculation formula is as follows: ΔT 变化率 =(ΔT i -ΔT0) / ΔT i ×100% where ΔT i is the temperature difference in the i-th power cycle, and ΔT0 is the initial temperature difference.

5. The power cycle test method for automotive-grade silicon carbide devices according to claim 1, characterized in that The preset threshold is 20%-40%.

6. The power cycle test method for automotive-grade silicon carbide devices according to claim 1, characterized in that In step (1), when performing the initial power cycle on the silicon carbide device to be tested, it also includes performing an initial electrical performance detection on the silicon carbide device to be tested to exclude initial defective devices.

7. The power cycle test method for automotive-grade silicon carbide devices according to claim 1, wherein The measurement positions of the infrared temperature sensor cover the central area and the edge area of the bottom plate of the silicon carbide device, and its installation method ensures that the temperature data of the central and edge positions can be obtained synchronously.

8. The power cycle test method for automotive-grade silicon carbide devices according to claim 1, characterized in that: The calculation of the temperature difference change rate is carried out in real time, and the data is updated after each power cycle.

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