Creep Behavior of Aluminum Alloy Foils for Microelectronic Circuits

摘要

Creep behavior of Al-1 mass percent Si-0.5 masspercent Cu alloy foils with different thicknesses (10-500 #mu#m)produced by rolling and subsequent annealing has beeninvestigated. The results showed that the stress exponentvaried from 7.9 to 10.4, depending on the specimen thickness.Taking the presence of silicon phase particles into account,threshold stress #sigma#_(th) was introduced to interpret thehigh stress exponent. The modified stress exponent was about5 with the effective stress, #sigma#-#sigma#_(th), where#sigma# is the applied stress. Subgrains were observed byTEM in the specimens during the steady state creep. Thus, itwas reasonably deduced that the creep proceeded following themechanism in which the deformation was controlled bydislocation climb. The creep rate of the specimens with thesame texture decreased with increasing specimen thickness.Another possible factor affecting the creep rate was the textureformed in rolling and subsequent annealing. The textures ofspecimens with different thicknesses were assessed byorientation distribution function.