title: Catalytic behavior of Sn/Bi metal powder in anhydride-based epoxy curing.
abstract: In this paper, we report the catalytic activity of the Sn/Bi alloy beads and its acceleration of the exothermic epoxy curing reactions in various thermal conditions and bead compositions. As being used as low-melting solder balls in electronic interconnection processes with various epoxy systems, it was found that the Sn/Bi beads substantially lowered the exothermic peak temperature of the diglycidyl ether of bisphenol A (DGEBA)/anhydride systems in up to ca. 140 degrees C depending on different types of anhydride curing agents. The catalytic activation of Sn/Bi powder was initiated with a small amount of Sn/Bi powder, for example, lowering ca. 50 degrees C of the exothermic peak temperature by adding only 0.1 vol% of Sn/Bi powder. The catalytic capability of the powder was increased by using smaller sized beads corresponding to larger catalytic surface area at the same volume fraction. Exhibiting a latent catalytic effect, the catalytic activity of Sn/Bi powder was remained latent at temperatures lower than 100 degrees C in isothermal conditions.
authors.affiliation: Electronics and Telecommunications Research Institute, 138 Gajeongno, Yuseong-gu, Daejeon 305-700, Republic of Korea.
authors.forename: Keon-Soo
authors.initials: KS
authors.lastname: Jang
authors.forename: Yong-Sung
authors.initials: YS
authors.lastname: Eom
authors.forename: Jong-Tae
authors.initials: JT
authors.lastname: Moon
authors.forename: Yong-Soo
authors.initials: YS
authors.lastname: Oh
authors.forename: Jae-Do
authors.initials: JD
authors.lastname: Nam