Test systems

RBSOA / SCSOA Testing Depending on the quality standards during the production of different IGBT and MOSFET module types a RBSOA and  SCSOA test is performed. The range of systems last from stand-alone laboratory systems with manual feeding to valuate DUTs during the developing process to full automated shift operation production lines. For RBSOA and SCSOA tests it is essential that the DUT undergoes a real stress test during switching and not just turning on and off the DUT. To reach a real stress test several criteria must be fulfilled like

• A very low stray induction of the complete system otherwise it will be just switching without real stressing during switching
• Accurate data logging with the highest possible resolution for analyzing the measuring results like
  • du / dt value
  • di / dt value
  • switching times
  • clamping voltage
  • peak voltages
  • collector current
  • gate voltage
• Complete traceability of each DUT for later analysis saving the measuring data in databases with upload to the company network if necessary.
• Example contact unit 1200 V / 2000 A RBSOA & 1200 V / 8000 A SCSOA with short circuit detection option
• In a full-automated shift operation production line

Advantages:

• Measuring equipment adapted for each product to get the highest possible resolution
• Customized DC Link for each DUT to minimize ESL
• Individual Gatedrive stage
• Contact check unit to ensure the DUT is connected proper before applying high voltage
• Signal Multiplexer for DUTs in half bridge configuration to save money and space instead of using a second oscilloscope
• Short circuit detection option to prevent uncontrolled discharging of the DC Link into the system during a DUT failure preventing welding the DUT to needles and unnecessary maintenance work at a contact unit.

For the High Temperature Reverse Bias tester we have developed a very compact test system. The system is capable to test 4x DUTs with up to +/-6500 V and 200 °C. The system consist of the following:

• Industrial PC to control the system and log the data.
• Test system works 72h PC Independent (in case of PC-shutdown).
• The high voltage power supplies.
• A standard meter to monitor the current and voltage.
• A special developed safety system.
• 4x temperature regulators.
• Separate heating and cooling for the 4x DUTs.

For a continuous quality control during the production of different electronic semiconductors HTOL Tests are performed. The DUTs are cycled for a specific time (100h -1000h) most of the time under high temperature in a heating chamber. Different JEDEC standards define the individual test for each DUT which is interpreted by  the hardware and software. The complete test will be interpreted by analysis tools. The system consist of the following:

• Industrial PC to control the system and log the data
• The high power supplies
• A standard Oscilloscope to monitor the current and voltage
• Multiplexer to switch each DUT to the Scope for V-measurement
• Current-limitation for each DUT
• Separate contacting for the 80 DUTs placed into a heating chamber up to 260°C

Low volume Production Line ZTH Test-System 150 A     and all parameters of a FET or FET-modules

• VSD diode
• BVDSS
• IDSS (forward/reverse) with leakage current compensation
• DIDSS (forward/reverse) with leakage current compensation
• IGSS / DIGSS
• VGSTH
• RDSON
• ZTH, ZTH loop
• C-Capacitor
• R-Resistor
• R-Shunt
• …

Including a manual contacting-station.

All set point and measuring functions are based upon the measuring module. For calibration, this module is just measured with a suitable instrument, and the result is sent to the tester and stored in non-volatile memory. There are especially no potentiometers involved in calibration. We provide a tool for automatic calibration, based on a calibrated digital multimeter and additional circuitry to cover all measuring ranges. This tool enables especially our international customers to calibrate by themselves or to check the tester’s DC specification periodically. The system generates a calibration report automatically with the comparison of tester and multimeter results.