PCB板TEA脉冲CO_2激光微孔研究

Investigation on the Laser Microvia PCB Using TEA CO_2 Pulsed Laser

印刷电路板(PCB)微孔技术是实现高密度互联技术的关键,我国在这方面的研究还刚刚起步,所采用的激光器基本依赖进口,投资成本高,后期维护费用昂贵。研究了聚焦透镜焦距、激光腔内结构、外光阑、扩束系统及其组合方式对PCB激光微孔特性的影响,通过对国产的TEACO_2脉冲激光器的激光光束输出模式进行改善、光学系统进行优化,得到了直径在φ170μm以下、孔形良好的微孔。

Laser microvia is the key technology for high density interconnect （HDI）, however there is little related researches in China. The setup for laser microvia almost depends on input, which is not only too expensive for investment, but also for maintaining. The effects of the aperture in or out of the laser resonator, expanded beam system, focus of the lens on the microvia characteristics using self-developed TEA CO2 laser have been experimentally studied in this paper. The results show that it is helpful to get microvias with good quality and small diameter by using shorter focus, higher magnification ex pander, small outside aperture and suitable inside aperture. Less than 170μm diameter and regular shape microvia can be obtained by using the optimal optical system and output model of laser.