Precise IGBT power device static parameter test solution

overview

IGBT and its application development

         IGBT (Insulated Gate Bipolar Transistor) is the core device of power control and power conversion. It is a composite fully controlled voltage-driven power semiconductor device composed of BJT (Bipolar Transistor) and MOS (Insulated Gate Field Effect Transistor). , has the characteristics of high input impedance, low conduction voltage drop, high-speed switching characteristics and low conduction state loss, and occupies a dominant position in high-frequency and medium-power applications.

Appearance of IGBT module

IGBT structure and equivalent circuit diagram

At present, IGBT has been able to cover the voltage range from 600V to 6500V, and its applications cover a series of fields from industrial power supplies, frequency converters, new energy vehicles, new energy power generation to rail transit, and national grid.

Main test parameters of IGBT power semiconductor devices

         In recent years, IGBT has become a particularly eye-catching power electronic device in the field of power electronics, and has been more and more widely used, so the test of IGBT has become particularly important. The test of lGBT includes static parameter test, dynamic parameter test, power cycle, HTRB reliability test, etc. The most basic test in these tests is static parameter test.

         IGBT static parameters mainly include: gate-emitter threshold voltage VGE(th), gate-emitter leakage current lGEs, collector-emitter cut-off current lcEs, collector-emitter saturation voltage VcE(sat), freewheeling Diode voltage drop VF, input capacitor Ciss, output capacitor Coss, and reverse transfer capacitor Crsso only when the static parameters of the IGBT are guaranteed to have no problem, can the dynamic parameters (switching time, switching loss, reverse recovery of the freewheeling diode) be performed. , power cycle, and HTRB reliability are tested.

Difficulties in testing IGBT power semiconductor devices

         IGBT is a composite fully-controlled voltage-driven power semiconductor device composed of BJT (bipolar transistor) and MOS (insulated gate field effect transistor), which has the advantages of high input impedance and low conduction voltage drop; at the same time IGBT chip is a power electronic chip, which needs to work in the environment of high current, high voltage and high frequency, and has high requirements on the reliability of the chip. This brings certain difficulties to IGBT testing:

1. IGBT is a multi-port device, which requires multiple instruments to be tested together;

2. The smaller the leakage current of the IGBT, the better, and high-precision equipment is required for testing;

3. The current output capability of the IGBT is very strong, and it is necessary to quickly inject a 1000A current during the test and complete the sampling of the voltage drop;

4. The withstand voltage of lGBT is high, generally ranging from several thousand to ten thousand volts, and the measuring instrument is required to have the ability of high voltage output and nA level leakage current test under high voltage;

5. Since the IGBT works under strong current, the self-heating effect is obvious, and it is easy to cause the device to burn out in severe cases. It is necessary to provide a us-level current pulse signal to reduce the self-heating effect of the device;

6. The input and output capacitance has a great influence on the switching performance of the device. The equivalent junction capacitance of the device is different under different voltages, so C-V testing is very necessary.

Precise IGBT power semiconductor device static parameter test solution

         The precise IGBT power device static parameter test system integrates multiple measurement and analysis functions, and can accurately measure the static parameters of IGBT power semiconductor devices. Support the measurement of power device junction capacitance in high voltage mode, such as input capacitance, output capacitance, reverse transmission capacitance, etc.

IGBT test system

Precise IGBT power device static parameter test system configuration is composed of a variety of measurement unit modules. The modular design of the system can greatly facilitate users to add or upgrade measurement modules to adapt to the ever-changing needs of measuring power devices.

"Double high" system advantages

         high voltage, high current

         With high voltage measurement/output capability, voltage up to 3500V (maximum expandable to 10kV)

         With large current measurement/output capability, current up to 4000A (multiple modules in parallel)

         high precision measurement

         nA level leakage current, μΩ level on-resistance

         0.1% accuracy measurement

         Modular configuration

         A variety of measurement units can be flexibly configured according to actual test needs The system reserves upgrade space, and measurement units can be added or upgraded later

         High test efficiency

         Built-in dedicated switch matrix, automatically switch circuits and measurement units according to test items

         Support one-key test of all national standard indicators

         Good scalability

         Support normal temperature and high temperature testing, flexible customization of various fixtures

"Magic cube" system composition

         Precise IGBT power device static parameter test system is mainly composed of test instruments, host computer software, computer, matrix switch, fixture, high voltage and high current signal lines, etc. The whole system adopts the static test host independently developed by Proceed, with built-in measurement units of various voltage and current levels. Combined with the self-developed host computer software to control the test host, different voltage and current levels can be selected according to the needs of the test project to meet different test requirements.

         The measurement unit of the system host mainly includes Precise P series high-precision desktop pulse source measure meter, HCPL series high-current pulse power supply, E series high-voltage source-measurement unit, C-V measurement unit, etc. Among them, the P series high-precision desktop pulse source measuring unit is used for gate driving and testing, and supports a maximum of 30V@10A pulse output and testing; the HCPL series high-current pulse power supply is used for current testing between collectors and emitters and freewheeling diodes The test, 15us ultra-fast current rising edge, built-in voltage sampling, a single device supports a maximum pulse current output of 1000A; E series high-voltage source test unit is used for voltage and leakage current testing between collector and emitter, and supports a maximum voltage of 3500V output, and has its own current measurement function. The voltage and current measurement units of the system adopt multi-range design with an accuracy of 0.1%.

"One-key" test item of national standard full index

         Precise can now provide a complete test method for IGBT chip and module parameters, and can easily realize the test of static parameters l-V and C-V, and finally output the product Datasheet report. These methods are equally applicable to wide bandgap semiconductors SiC and GaN power devices.

IGBT static test fixture solution

         For IGBT products with different package types on the market, Precise provides a complete set of fixture solutions, which can be used for testing TO single tube, half-bridge modules and other products.

Summarize

         Guided by independent research and development, Precise has been deeply involved in the field of semiconductor testing, and has accumulated rich experience in I-V testing. It has successively launched DC source measuring meters, pulse source measure units, high-current pulse source measure meters, high-voltage source test units and other test equipment, which are widely used. Applicable to university research institutes, laboratories, new energy, photovoltaics, wind power, rail transit, inverters and other scenarios.