화학공학소재연구정보센터
Applied Surface Science, Vol.208, 463-467, 2003
Laser cleaning of printed circuit boards
Laser cleaning of printed circuit boards (PCB) has been studied in this paper. It is demonstrated that laser cleaning is a powerful tool to remove resin contaminants from printed circuit boards. A Nd:YAG laser is used as a light source for laser cleaning. The beam profile of the YAG laser is reshaped and homogenized into a square beam with uniform energy distribution in the focal plane of the focusing lens by using an optical system. The printed circuit board surfaces before and after laser cleaning were inspected by an optical microscope, analysed by X-ray photoelectron spectroscopy and monitored by an acoustic wave detection method. The cleaning threshold is about 75 MJ/cm(2) and no damage is observed below 400 mJ/cm(2). (C) 2002 Elsevier Science B.V. All rights reserved.