Megasonics: A Cavitation Driven Process

In this paper attention is given to different parameters playing a role in megasonic cleaning, which is based on gaseous cavitation such as gas type and concentration, acoustic drive pressure and their influence on sonoluminescence, the motion of a void, particle removal efficiency, uniformity and damaging. The cavitation process is a non-uniform process in itself, but also larger scaled non-uniformities can be observed for SL and PRE. Single bubble simulations show that only a limited bubble size distribution will be active in a megasonic field and that the main parameters to consider are the power and the bubble size affected by the saturation level of gas. Depending on the megasonic system and process conditions, a positive relation between SL and PRE is not always found but damage always increases along with PRE. In fact not the type of gas but the level of saturation is determining the success of the particle removal in a megasonic process.