Wave Soldering by Ultrasonically Induced Acoustic Streaming
Original Publication Date: 1985-Apr-01
Included in the Prior Art Database: 2005-Feb-18
Conventional wave soldering is not as good as other methods for filling plated through holes in circuit boards, partly due to high surface tension of solder. A wave formed by ultrasonic acoustic streaming would have the advantages of a wave-soldering process with the added benefits of a reduction in the apparent solder surface tension and ultrasonic cleaning of the workpiece. Acoustic streaming occurs with a large amplitude ultrasonic horn to produce a surface wave, similar to that caused by a jet of fluid. Ultrasonic waves propagate freely within this jet, and in regions beyond, so that the benefits of ultrasonic soldering are realized. The principal advantages are: (1) The wave, formed by acoustic streaming, washes away any impurities, trapped air, or flux. (2) There are no moving parts exposed to the solder .