High quality laser cutting of electronic printed circuit board substrates

摘要

Purpose - The purpose of this paper is to discuss laser cutting of FR4, and BT/Epoxy-based PCB substrates with 355 nm DPSS UV laser. Design/methodology/approach - The effects of various laser conditions such as scanning speed, assisting gas, repetition rate and interval between scans on the heat affected zone (HAZ) and charring are studied. The quality and morphology of laser cut PCB substrates are analyzed with optical microscopy, and scanning electron microscopy (SEM). Also, the laser cut PCB substrates are evaluated by humidity testing and thermal cycle testing. Findings - Multi-pass cutting at high scanning speed, with O_2 assist gas was found to be able to achieve high quality cutting with little charring. It was also found that a certain time interval between scans and higher repetition rates led to a reduced heat affected zone and less charring. Originality/value - This paper demonstrates high quality laser cutting of PCB substrates with no delamination, little charring and minimum HAZ. The developed process has important potential applications in the electronics industry.