Sintering behavior of a reactively bonded thick film gold ink

The sintering behavior of thick film reactively bonded Au films was studied using electrical re-sistance measurement and scanning electron microscopy. Isothermal firings were conducted at 350‡ to 850‡C for times up to three hours. The sintering process consists of three portions: 1) Burnoff of the binding resin at 350‡ to 450‡C. 2) A second stage involving neck growth between the gold particles with an activation energy of ∼ 15 Kcal/mole and a time exponent of 5.5 to 6.5 corresponding to surface diffusion control and 3) a third stage of densificat ion by pore annihila-tion and grain growth. The activation energy in stage III of 35–45 Kcal/mole agrees closely with bulk diffusion control. Electrical resistance change appears to be a useful method for studying particularly the initial stages of sintering.