Reliability of non-hermetic pressure contact IGBT modules

The reliability of a newly developed non-hermetic pressure contact module f or high power applications was investigated. Besides the standard reliabilt y tests one focus was the evaluation of the resistance to humidity. A highl y accelerated temperature and humidity stress test (HAST) was introduced to shorten the learning cycles during the design phase. The main focus of int erest however was on the reliability of a non-hermetic pressure contact mod ule in two relevant application situations: the life expectancy under therm al (power) cycling conditions and the capability of a module, when it fails with a short circuit, to remain in that failure mode even under full appli cation load. Based on an experimental assessment of the respective capabili ties under test conditions, theoretical estimations then predict performanc e and margins in both application situations. (C) 2001 Elsevier Science Ltd . All rights reserved.