High melting point copper-gold-tin brazing alloy for chip carriers

摘要

Brazing of elements to electronic chip carrying substrates requires brazing materials strong at high temperatures used to remove and replace chips. Flanges and pins are brazed with Au:Sn brazing alloys modified during brazing by addition of copper to the brazing material to promote formation of the higher melting point beta phase of the alloy and a Group VIII metal to draw Sn out of the melt by gettering, also to promote formation of the beta phase of the alloy and to thicken the braze material. A copper preform is plated with Ni and juxtaposed with surfaces to be brazed and the brazing material to add Ni and copper to the melt.