Laser prototype system for creating high density patterns on PCB

Abstract

The interconnection complexity of the PCB (Printed Circuit Boards) is still growing and new technologies are introduced in the production of high density printed circuit boards. Recently the Laser Direct Imaging (LDI) technology is used for imaging electric circuits directly on PCB without the use of a phototool or mask. We presents our laboratory system for Laser Direct Imaging designed for tracks and spaces on PCB with minimum track/space widths distance of 50/50 µm. In comparison with conventional photolithography method, this technology is much better for 50/50 µm track and spaces. In our research we used photoresist with 50 µm resolution, but in case of using laser photoresists with better resolution (e.g. 25 µm) it is possible to image tracks in super-fine-line technology (25/25 µm). Our laboratory system for LDI consist of diode UV laser (λ=375 nm, P=9 mW), optical scanner head, telescope and XY planar table, which extends scanner head working area into 15 x 25 cm usable area. A sophisticated computer software was developed to control this system.