Interfacial reactions in the Co/In/Cu and Ni/In/Cu samples

To provide fundamental understanding for the solid-liquid interdiffusion process using indium-based solders, interfacial reactions in the Co/In, In/Cu, Ni/In, Co/In/Cu and Ni/In/Cu samples at the Co/In, In/Cu and Ni/In interfaces are systematically determined. Coln(3) phase is formed in the Co/In couples reacted at 200, 350 and 500 degrees C. Cu-11 In-9 and a two-phase mixture region are observed in the In/Cu couples reacted 200 degrees C, and delta-Cu-7 In-3 and eta'-Cu-2 In phases are found at 350 and 500 degrees C. In the Ni/In couples, the In7Ni3 phase is formed at 200 and 350 degrees C, while InNi and In3Ni2 phases are found at 500 degrees C. Except for the formation of an unknown ternary phase in the Co/In/Cu sample reacted at 350 degrees C, the reaction phases in the sandwich-type ternary samples are the same as those in the binary couples, and no significant cross- interactions are observed both in Co/In/Cu and Ni/In/Cu samples. The indium consumption rates are faster in the Ni/In/Cu samples. Their consumption rates are estimated based on the indium accumulation in the reaction phases. (C) 2019 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.