Encapsulation of Power Modules for Extreme Environment Electronics

摘要

It has been demonstrated that wideband gap devices fabricated from SiC, or GaN grown onrnSiC, can operate over a much wider temperature range than traditional silicon or GaAs devices.rnHowever, most of the packaging technology in use to today was developed for silicon or GaAs devicesrnand much of this technology is fundamentally limited in its temperature range. For examplernencapsulation and housing materials often have maximum service temperatures of 200℃. Therefore,rnnew technologies are needed to enable the wide spread use of these new devices at elevatedrntemperatures. In particular, the identification or development of suitable gels and housing materials forrnpower electronic modules operating at high temperature is a critical issue. These power modulesrnoperate with very high internal voltages, and gels and polymeric housings have traditionally been usedrnto prevent arcing within the packages.rnThis paper seeks to address one of these fundamental issues, which is the dielectric breakdownrnstrength associated with the encapsulating gels and housing materials under extreme environmentalrnconditions. Several potential materials were selected and long term reliability data on a number ofrnencapsulation gels and housing materials that are suitable for operation of these devices in excess ofrn180℃ is provided. Baseline electric breakdown data measured at high temperature as well as data onrnaged samples has been collected.