应用激光, 2017, 37 (2): 262, 网络出版: 2017-06-08
不同偏振态下飞秒激光在FPC上打孔特性研究
The Characteristics of Femtosecond Laser Drilling on FPC with Different Polarization States
摘要
偏振态是激光光束的重要特征之一, 不同偏振态的激光在柔性电路板(FPC)上打孔特性不同。介绍了采用以聚酰亚胺为基材单面电解铜式的FPC材料损伤阈值理论计算方法, 并分析了利用液晶空间光调制器、1/2波片和1/4波片组合实现激光束四种偏振态的控制方法, 得到四种偏振态: 线偏振、圆偏振、径向偏振和角向偏振。通过不同能量的打孔实验测定出柔性电路板在800 nm单脉冲飞秒激光下的损伤阈值为25.44 J/cm2, 并进行了相同功率下四种偏振态激光束对同一FPC材料进行打孔实验。实验结果表明, 径向偏振和角向偏振具有更好的圆度和更大的孔径。
Abstract
Polarization state is one of the important characteristics of the laser beam, and the polarization states will affect the drilling quality on the flexible circuit board (FPC). A theoretical calculation method for damage threshold of FPC material with polyimide as substrate was presented, and the way of obtaining four polarization states (linear, circular, radial and azimuthal) is proposed by combining a liquid crystal spatial light modulator, a half-wave plate and a quarter-wave plate. The damage threshold of the flexible circuit board processed by the 800 nm femtosecond laser is calculated to be 25.44 J/cm2 through drilling experiments of different processing energy. Experiments with different polarization states were also done on the condition of the same energy and the same sample. The experimental results show that the radial polarization and angular polarization have better roundness and bigger diameter.
翟中生, 郭钊, 汪于涛, 吕清花, 陈列, 娄德元, 杨奇彪, 刘顿. 不同偏振态下飞秒激光在FPC上打孔特性研究[J]. 应用激光, 2017, 37(2): 262. Zhai Zhongsheng, Guo Zhao, Wang Yutao, Lv Qinghua, Chen Lie, Lou Deyuan, Yang Qibiao, Liu Dun. The Characteristics of Femtosecond Laser Drilling on FPC with Different Polarization States[J]. APPLIED LASER, 2017, 37(2): 262.