Zuverlässigkeitsuntersuchungen von Aluminium-Drahtbonds auf Gold Dickschichtleiterbahnen

The ageing characteristics of aluminium wire bonds on five different thick film gold inks were investigated. The assessment criteria selected were the pull strength and the electrical resistance of the bonds. A correlation between these does not exist. Under stress the bond strength first declines sharply, however, afterwards stabilizes at a level that can just be accepted. The electrical resistance of the bond, in contrast, rises slowly, but then reaches values, at which the contact is no longer guaranteed. Internal oxidation is proposed as a new explanation for this behaviour.