UV laser cutting of glass-epoxy material for opening flexible areas of rigid-flex PCB

Abstract

Purpose – The purpose of this paper is to form good cutting qualities in glass-epoxy material for opening flexible areas of rigid-flex printed circuit boards (PCB) by ultraviolet (UV) laser cutting. Design/methodology/approach – The cut width and cut depth of glass-epoxy materials were both observed to evaluate their cutting qualities. The heat affected zone (HAZ) of the glass-epoxy material was also investigated after UV laser cutting. The relationships between the cut width and the parameters of various factors were analyzed using an orthogonal experimental design. Findings – The cut width of the glass-epoxy material gradually increased with the increment of the laser power and Z-axis height, while cutting speed and laser frequency had less effect on the cut width. Optimal parameters of the UV laser process for cutting glass-epoxy material were obtained and included a laser power of 6W, a cutting speed of 170 mm/s, a laser frequency of 50 kHz and a Z-axis height of 0.6 mm, resulting in an average cut width of 25 μm and small HAZ. Originality/value – Flexible areas of rigid-flex PCBs are in good agreement with the cutting qualities of the UV laser. The use of a UV laser process could have important potential for cutting glass-epoxy materials used in the PCB industry.