Gold-Tin Solder Joints Having Reduced Embrittlement

摘要

A metal interconnection for two workplaces such as a semiconductor chip and an insulating substrate. The first workpiece ( 101 ) has a first contact pad ( 201 ) with a gold stud ( 110 ); the second workplace ( 103 ) is covered with an insulating layer ( 213 ) and a window in the layer to a second contact pad ( 211 ). The interconnection between the second pad and the gold stud is a 278° C. eutectic structure ( 111 ) with about 80 weight percent gold and about 20 weight percent tin. The eutectic structure has a Young's modulus of 59.2 GPa and a lamellar micro-structure of the phases Au₅Sn and AuSn. There is substantially no metallic tin at the second contact pad.