ABSTRACT
In automated soldering of a printed wiring board (PWB), there are two basic methods: wave soldering and reflow soldering. The wave soldering method applies molten solder to the bottom side of a PWB. Application of solder and heating are done simultaneously in the wave soldering. In reflow soldering, however, solder paste is printed on a PWB before heating. A controlled amount of solder and flux is applied to the area to be soldered, which results in higher assembly yield. A common technique of applying solder and flux is to print a pattern of solder paste. Solder paste becomes an indispensable material for the electronics assembly process.
