The manufacturing of printed circuit boards (PCBs) is carried out traditionally with fotoresist and etching. The pressure from the constant need of ever smaller features in electronics has, however, caused also need to manufacture circuits with smaller feature size and better accuracy also on the PCB. Laser has traditionally been used in micro via drilling. This study concentrated on the processing of the copper layer on the top of the PCB. The aim of the study was to validate the possible speed and accuracy of laser processing
The lasers used were typical Q-switched diode pumped Nd:YAG and Nd:YVO lasers. The wavelength of the laser used in processing has clear effect on the processing and on the accuracy of processing. The thickness of processed copper laser layer was in this study up to 35 µm. The polymer in board was traditional FR4. Processing carried out with too high a laser power required in case of long wavelength destroys the polymer underneath the copper. With proper parameter combination the processing can be considerably efficient and concentrate only to the copper layer. The study showed, that laser can be used to process 21 µm wide grooves with 26 µm distance.