Product Code: ICAL07_M507

Laser Dicing of Electronics Printed Circuit Boards using a DPSS UV Nd:YVO4 Laser
Authors:
Xincai Wang, Singapore Institute of Manufacturing Technology (SIMTech); Singapore Singapore
Z. L. Li, Singapore Institute of Manufacturing Technology (SIMTech); Singapore Singapore
B. K. Lok, Singapore Institute of Manufacturing Technology (SIMTech); Singapore Singapore
J. L. Tan, Singapore Institute of Manufacturing Technology (SIMTech); Singapore Singapore
K. H. L. Li, Singapore Institute of Manufacturing Technology (SIMTech); Singapore Singapore
T. Chen, Singapore Institute of Manufacturing Technology (SIMTech); Singapore Singapore
D. K. Y. Low, Singapore Institute of Manufacturing Technology (SIMTech); Singapore Singapore
Presented at ICALEO 2007

Miniaturization, function integration and high density interconnection are manufacturing demands in the electronic industry. These demands necessitate the use of thin, rigid and flexible printed circuit board (PCB) substrates to be used in the electronic devices. The cutting of thin rigid and flexible PCB substrates is critical in the manufacturing of the electronic products. But for thin PCB substrates of less than 300 μm, mechanical cutting method encounters problems such as delamination, deformation, and high cost due to frequent changes of tooling and fixtures for different board designs. Such issues create opportunities for laser cutting of thin PCB substrates. As a non contact process, laser cutting method is able to precisely cut contours with any shape and clean cut edges with minimum burrs, no delamination and no distortion. In this paper, the results on 355 nm DPSS UV laser cutting of FR4 PCB substrates are reported. The cutting was conducted with both scanning optics and fixed optics in order to have a complete understanding of the process. The effects of various conditions such as assist gas type, laser cutting speed, laser repetition rate, and interval between scans on the cutting quality in terms of heat affected zone (HAZ) and charring were studied. The quality and morphology of laser cut PCB substrates were evaluated with optical microscope, SEM, Raman spectroscopic analysis, etc. High quality laser cut PCB substrates with no delamination and very little charring was demonstrated. The mechanism for the reduction of HAZ and charring was discussed. The developed process has potential application in manufacturing of electronic products.