Process for controlled braze joining of electronic packaging elements

摘要

A method of forming a brazed joint between conformal surfaces by providing a Sn gettering metal layer on at least one of the conformal surfaces, placing a mass of a low melting Au Sn alloy between the conformal surfaces, heating the resultant assembly to a temperature in excess of the melting point of the alloy, simultaneously with heating applying a pressure to force the surfaces together to squeeze the major portion of the molten Au-Sn alloy from between the surfaces, and cooling the assembly, the bond between the surfaces formed of a relatively thin higher melting Au-Sn alloy resulting when the major portion of the alloy is removed allowing the remaining Sn to combine with the Sn gettering layer to reduce the relative amount of Sn in the alloy.