Study on the speed threshold of PCB cutting using three kinds of Q-switched lasers

With the development of laser technology, nanosecond lasers have been widely used in material micromachining due to their advantages such as the narrow pulse width and high-power density. The high-order harmonic generation procedures have been invented to obtain 532, 355, and 266 nm radiations based on a 1064 nm Nd:YAG laser. In this paper, the influence of different sample moving speeds and laser power on the cutting effects were studied using three kinds of laser sources. It can be seen that the state of the cutting surface has not changed obviously when the laser power was increased. The self-defined cutting threshold, i.e., 2.25 W·s/mm, has been obtained by investigating the processing morphology with the power of 1.35 W at different sample moving speeds for both a 355 nm laser and a 266 nm laser. Increasing the laser power to 3.20 W, we obtained the cutting threshold of about 1.80 W·s/mm for a 355 nm laser. The scorching status of the surfaces cut by both a FHG laser and a SHG laser have been found to be more serious than that cut by a THG laser. The experiments have demonstrated that the machining efficiency increases with the laser power, but the cutting quality becomes worse at the same time. The results are thought to be useful for the PCB cutting applications in the industrial fields.