Plasma based soldering by indirect heating

摘要

A method of soldering without the use of flux, wherein a plurality of solder bumps are deposited on a first surface and a plurality of solder pad locations are prepared on a second surface. The first and second surfaces are placed immediately adjacent to one another, placing each the plurality of solder bumps in the proximity of a corresponding solder pad location on the second surface. The first surface, the second surface and the solder are placed in a chamber which is evacuated to a low pressure. A plasma is excited within the chamber which heats the first and the second surfaces, thereby heating the plurality of solder bumps and the plurality of solder pad locations by heat conduction and reflowing the plurality of solder bumps on the first surface and on the plurality of solder pad locations on the second surface to form a plurality of solder bonds therebetween.