Low resistance and low temperature bonding between Silver and Indium

Conductive adhesives are commonly used for the interconnections of fine pitch, small packages like mobile applications. Since conductive particles connect mechanically with contact pads to give somewhat higher contact resistance, a metallurgical interconnection, which provides both fine pitch and low resistance, was studied using silver ball and indium which can be made at low temperatures. The connection resistance of the In-Ag metallurgical interconnection was lower than that of the Ni/Au-Ag mechanical interconnection and the former showed little dependency on the bonding load in contrast to the latter.