TIN BISMUTH SOLDER PASTE, AND METHOD USING PASTE TO FORM CONNECTION HAVING IMPROVED HIGH TEMPERATURE PROPERTIES

摘要

A solder paste (24 in Fig. 1) of the type utilized in forming a solder connection (32 in Fig. 2) for a microelectronic package comprises a mixture of compositionally distinct metal powders. The paste comprises a first metal powder formed of tin-bismuth solder alloy. The paste further comprises a second metal powder containing gold or silver. During reflow, the gold or silver alloys with the tin-bismuth solder to increase the melting part and enhance mechanical properties of the product connection.