Process for controlling solder joint geometry when surface mounting a leadless integrated circuit package on a substrate.

摘要

A solder joint assembly technique applies controlled volumes of solder to pads of both package and substrate (31, 32). The two units are positioned adjacent each other with the pads and solder deposits mechanically maintained in registration with each other (34, 35). The assembly is reflowed and the final separation between package and substrate at which the resulting solder joint solidifies is mechanically controlled in order to control a geometry of the resultant solidified joint (36, 37). The solder volume deposits may assume various forms including spherical bumps and solder paste deposits.