Science and engineering in laser surface cleaning

Abstract

Laser cleaning was demonstrated both theoretically and experimentally to be an effective cleaning technique for removing particulate and film-type contaminants from solid surfaces in this paper. The laser-induced removal of film-type contaminants from IC (Integrated Circuit) packages, IC mould, Printed Circuit Board and flexible circuit was studied. The cleaning models were established for removal of particles from substrate surfaces without and with a thin liquid layer by taking adhesion forces and cleaning force into account. The models not only explain the influence of laser fluence on cleaning efficiency, but also predict the cleaning thresholds. Laser-induced removal of particles from magnetic sliders and disk surfaces was investigated. Monitoring of laser cleaning by acoustic wave, electric field signal and particle counter was also addressed.