To ensure the accuracy of IGBT chip avalanche test results, you can start from the following aspects:

Calibration and accuracy of 1. test equipment
Periodic calibration
Regularly calibrate key test equipment such as power supplies, oscilloscopes, and current sensors to ensure the accuracy of their measurements.
Follow the equipment manufacturer's recommendations and relevant standards for calibration.
High-precision equipment selection
Choose measuring equipment with high resolution and high accuracy. For example, choose an oscilloscope with a wide enough bandwidth and a high sampling rate.

Control of 2. test environment
Temperature stability
Keep the test environment temperature stable and avoid the influence of temperature fluctuation on the test results. An incubator or air conditioning system can be used to control the ambient temperature.
Electromagnetic interference elimination
Ensure that there are no strong sources of electromagnetic interference in the test site, such as large motors, high-frequency communication equipment, etc.

Optimization and Verification of 3. Test Circuit
Circuit layout rationality
The layout of the measurement test circuit is reasonably designed to reduce the influence of parasitic inductance and capacitance. Shorten the length of wiring, the use of appropriate wiring.
Accuracy of circuit element parameters
Select resistors, capacitors, inductors and other components with high precision and good stability, and ensure that their parameters meet the test requirements.
Circuit Verification
Prior to formal testing, verify the test circuit for short circuits, open circuits, or poor connections.

4. test sample preparation and handling
sample integrity
Check whether the IGBT chip has physical damage, pin oxidation and other problems to ensure that the sample is intact.
Correct installation and connection
Install the chip on the test fixture according to the standard installation method, and ensure that the pin connection is firm and the contact is good.

Normalization of 5. test operation
Slow Boost
When increasing the power supply voltage, it should be slowly and evenly boosted to avoid inaccurate results caused by sudden changes in voltage.
Sufficient test time
Give enough test time to ensure that the chip reaches a stable working state in the avalanche state, so as to obtain accurate measurement data.
multiple repeatability test
The same chip is tested repeatedly, and then the results are statistically analyzed to remove outliers to improve the reliability of the results.

6. data analysis and processing
Correct waveform interpretation
The operator should have the ability to correctly interpret the oscilloscope waveform and accurately identify the key parameters such as the starting point and peak value of the avalanche.
data filtering and smoothing
Appropriate filtering and smoothing of the collected data is performed to reduce the interference of noise on the results.

For example, in a power electronics research and development laboratory, in order to ensure the accuracy of IGBT chip avalanche test results, they not only regularly calibrate the test equipment, but also set up an electromagnetic shielding room for testing, and conducted strict operation training and specification requirements for testers. Through these measures, the accuracy and reliability of the test results are greatly improved, and strong support is provided for product development and quality control.