The Effects of Ultrasonic Cleaning on Device Degradation

An investigation of the use of ultrasonic agitation for cleaning printed circuit boards using CFC‐based solvents has shown that, under the standard conditions required to produce clean assemblies, no damage will occur to the components studied. Damage can only be induced by use of anomalously longer times or higher power densities. In all cases in which damage has been induced, it is of a purely mechanical nature due to fatigue, and is located on the device bond‐wires and/or the package legs. Cleaning using CFC‐based solvents under standard ultrasonic conditions of power density and time etc. is readily achieved within 2 minutes, even with a minimum stand‐off height.