The work done by the IPC Solder Product Value Council no discernible difference between the various SAC alloys that were studied therefore if you already have SAC305 in your process and on the assembly then it is desirable that you stay with that alloy for all soldering applications for that assembly. This will eliminate the opportunity for the generation of any none eutectic alloys which have the potential for reliability issues. Also using a single alloy will make it easier should any rework or repair ever be needed in the future.
Senior Applications Chemist
Dr. Poole is a Senior Applications Chemist in Henkel Technologies, electronics assembly materials application engineering group. He is responsible for all of Henkel's assembly products including soldering products, underfills, PCB protection materials, and thermally conductive adhesives.