Publications Details

Compatibility of Au base thick films with solder alloys: Solid state growth of intermetallics

Stephens, J.J.; Romig Jr., A.D.

Long term reliability of solder joints in thick film Au hybrid microcircuits require either minimization of the solid state growth of intermetallics or verification that if present, they do not compromise component performance. Intermetallic compounds such as AuIn{sub 2} or AuSn{sub 4} arise from the solid state reaction between Au thick films and 50Pb--50In or 63Sn--37Pb solder alloys, respectively; they are undesirable due to their brittle mechanical behavior caused by lack of a sufficient number of independent slip systems for plastic deformation. In addition, they may alter the resistivity of a circuit and thereby alter electronic performance. This paper will present a brief overview of the Au thick film inks/solder alloy systems whose intermetallic growth kinetics have been characterized at SNL, Albuquerque for hybrid microcircuit electronic applications. 6 refs., 3 figs., 2 tabs.