US EPA

2182217 

Journal Article 

DAMAGE-FREE ULTRASONICALLY-ASSISTED CLEANING OF PRINTED-CIRCUIT ASSEMBLIES 

Richards, BP; Burton, P; Footner, PK 

1993 

10 

3 

140-157 

WOS:A1993LM57000002 

The effects of ultrasonic agitation on electronic components during PCB cleaning have long been the subject of controversy. This paper summarizes the results of a series of studies into these effects for a range of components using CFC, aqueous and semi-aqueous cleaning media. The variations with exposure time and power density under various ultrasonic stress conditions are discussed. The results are encouraging and suggest that for a large range of commonly-used components there is a large margin of safety when employing currently accepted regimes of operation and good quality components. In addition, quartz crystal devices, although more susceptible to damage than ICs, will withstand ultrasonic exposure without deleterious effects for periods several times longer than those used for cleaning PCBs, once manufacturing defects have been screened out. In the case of hybrids, the sensitivity to damage is critically dependent on the type of package used. 

ULTRASONICS; PCB CLEANING; QUARTZ CRYSTAL DEVICES; HYBRID PACKAGES