The performance of electronics located in harsh environments is often affected by a combination of environmental factors. Qualification tests on such electronics are normally carried out by separate environmental tests such as temperature storage, temperature cycling and vibration tests. This approach may mask the effects of combined parameters, where degradation in a vibration environment may be accelerated by temperature related effects on material properties, for example.
This paper presents details of an initial study into the combined effects of temperature and vibration on wire bonded interconnections used in the production of high temperature electronic components. The study is focused on the testing of electronic components under the combination of temperature exposure up to 250°C and vibration loading with a frequency range between 50Hz and 2000Hz and acceleration up to 20g rms. The study covers the fundamental aspects of wire bond connections and their failure mechanisms, where the effect of wire loop height and length under separate and combined vibration and temperature tests has been investigated. The study has also assessed the effect on packaged silicon on insulator (SOI) devices assembled into ceramic packages under representative combined temperature and vibration profiles. The work has shown that the combined effect of temperature and vibration has increased the susceptibility of wire bond interconnections to vibration induced failures and vibration testing under the applied temperature is recommended for assessment of components for harsh environments.
