IGBT module has characteristics of saving energy, easy installation, stable heat dissipation, etc., its great performance makes it bear “heavy tasks” in work. If the quality is not up to standard, the chip or the whole module will lose its utility or shorten its life, which will affect the normal operation of the whole device and even the product. In IGBT, NTC thermistor chip is needed for temperature monitoring and temperature control, so as not to affect the normal operation of IGBT module due to high operating temperature.
In order to discover the potential problems in IGBT in time and find out the hidden dangers, IGBT should be test for reliability, which helps to further understand the reliability of the products, so as to promote development rate of the product, optimize process, improve product quality. Analysis from a reliability perspective, the dominant failure mode for IGBT modules including chip failure and module aging failure. The reason of chip failure mainly includes the overheat, over-voltage, over-current, etc.. For example, overheat may be due to the high environmental temperature, the setting of temperature protection point is not suitable, temperature protection is not timely, excessive current device, device loss too high, etc.. The aging failure of IGBT module is mainly caused by the problems in the the electrode terminals, welding layer of shell, bonding wire of chip and other parts of the problem. Different failure modes can be evaluated by different reliability method. For example, the aging failure of the welding layer of the module can be determined by temperature cycle, temperature shock and power cycle.
In view of overheat problem of IGBT module running, the heat sink (including the general heat sink and heat pipe heat sink) is generally used in the module for overheat protection protection, and can be forced air cooling. High-accuracy NTC thermistor chip installed in IGBT module can effectively detect steady-state shell temperature (TC) of power module. According to the different IGBT module, the NTC thermistor chip for shell temperature measurement of IGBT module can be encapsulated on the same DCB or the high-accuracy NTC thermistor chip encapsulated on the single DCB, which makes shell temperature measurement of IGBT module more efficient and convenient.
微信公众号 广电计量《IGBT“芯”支持 可靠“体检”不可少！》