The Development Of IGBT Thermal Characteristics Test System Based On Electrical Method

IGBT（Insulate Gate Bipolar Transistor）as a new representative of power electronicdevices, has common advantage of insulated gate field effect transistor (MOSFET)and bipolar transistor (BJT), it is a Darlington structure which composed by MOSFETand BJT. It also has the advantages of high input impedance, low control power, lowswitching loss, simple drive circuit, high switching speed of MOSFET, the advantagesof low saturation voltage, high current density and high current handling capability ofBJT, it is an ideal switch device in power electronic field and has broad prospects fordevelopment and application. But for IGBT such a high-power device, in its normaloperating power loss will generate a lot of heat create self-heating, which will directlyaffect the thermal stress of IGBT, led to life shortened or even burnout, and also affectsurrounding devices. Therefore, it is necessary to carry out the studies to measure andanalyze thermal characteristics of such IGBT power devices. And a good thermalcharacteristics analysis instruments is so crucial to the research of device forscientists.In this paper, an electrical test system of IGBT thermal characteristics is study anddesigned based on measuring principle of IGBT thermal characteristics andFPGA-based embedded application technology. And the performance of the system istested. The main research is in the following areas:(1) According to the characteristics of IGBT, improved one measurement method ofthermal resistance for the system-specific, refer to the national military standardson the measurement method about thermal resistance of semiconductor device.(2) According to the tasks and requirements of thermal resistance test system, itproposed an overall design of the system. According to the thermal resistancemeasuring principle, the FPGA-based embedded application technology isintroduced. With FPGA as control core of the system logic, combined with theperiphery of the high-speed data acquisition system, SDRAM-based data storagemodule, LAN-based network communication module, current source withisolation type, isolation switch control circuit and PC to form the entire thermalcharacteristic test system.(3) According to the top-down design method, the system was divided into severalfunctional modules, and studied the various modules.(4) The performance of this system was tested. Using this system and the market mainstream system to measure the thermal resistance the same device, and themeasurement data were analyzed.