Power Semiconductor Reliability Test Equipment
Reliability verification equipment for the assessment of power semiconductor products, specialising in equipment for IGBT modules and related technologies.
IGBT Active Power Cycling Tester
The purpose of the Active Power Cycling Test Equipment is to characterise the wear out lifetime of the wire bond contacts to the IGBT and FRD die based upon IEC 60647-9.
This is achieved by cycling them with a high power current source to produce heat followed by a cooling period, resulting in a typical 50°C junction temperature swing for a typical length of 1Million cycles. As bond wires begin to lift or crack, the total Vce of the DUT may increase. This will be detected by the equipment and the test will be terminated after certain conditions are met.
The device chip temperature is determined by monitoring the Vce real time and looking up an equivalent temperature from a calibrated curve which is determined prior to the test. This is achieved using a hot plate oven heating
the device to a range of known temperatures and reading the device Vce at a set calibrated current.
The number of cycles and min and max temperatures are logged for the entire test whereas Vce waveforms are recorded for up to 5 hours prior to test termination.
Rth evaluation can be accurately determined from the characteristic heating and cooling curves and this data can be presented for the particular DUT.
This is a sophisticated test system which utilizes the Vce measurement to determine junction temperature excursions, however the system can be configured to operate as a simple IOT tester with simple on – off times and forced DC current control.
IGBT Passive Thermal Cycling Tester
Dynex have designed a simple 19” rack version of our usual multiple module cycler.
This is designed to be stand alone with its own local chiller for cooling the device under test after each heat cycle.
This has been designed to produce an accurate temperature cycling area on the mounting plate which will accommodate all sizes of IGBT modules as individual components, however it can be arranged to take multiple smaller components, by modifying the mounting arrangement on the plate.
Dynex can design the DUT plates to suit the particular components under test.
IGBT HTRB Test Equipment
One of the most common reliability tests is the High Temperature Reverse Bias test.
This test helps to make sure that devices deliver the performance specified from the
High voltage is applied to the device at elevated temperatures, up to 175°C.
Typical tests are a minimum of 1000 hours. The voltage and leakage currents can be
monitored to determine the performance of the device.
The latest designs now have forced air cooling solutions to prevent thermal
runaway when testing at temperatures up to 175°C.
IGBT Vge Blocking Tester
Another recognized failure mechanism in IGBT technology is for the gate structure to become leaky with temperature and no longer support the gate voltage. The Vge Blocking tester provides a simple test in accordance to Dynex qualification standards whereby the gate terminal voltage is maintained and the leakage current is monitored over time to assess any changes.
The Vge Blocking Tester is now built into the hotplate oven with an insulated split hinged lid which allows easy access for the mounting of devices. Up to 8 devices are mounted inside the hot plate oven where the devices can be operated at elevated temperatures up to 200°C.
The equipment also uses LabView based control software allowing for real time monitoring and statistics. Giving control of test durations and leakage current alarm points per device. Test records can also be saved for analysis offline.