Silicon cratering is one of the major obstacles to turn thermosonic copper wire bonding technology into a mass-production mode. The effects of reliability tests, i.e. aging test, temperature cycle test, and autoclave test on silicon craters of copper and gold wire-bonded Si substrate are discussed in this paper. Prior to reliability tests, wire-bonded specimens were examined by initial bond etch test. Results showed that there was no crack or silicon cratering observed in the selected samples. It was found that reliability tests, unlike improper bonding parameters, did not induce silicon craters at the Si substrate. However, reliability tests degraded the Si substrate and bonded interfaces, which were exposed later during destructive tests, i.e. wire pull test and ball shear test.
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