飞秒激光刻蚀FR-4覆铜板成形微细线路研究

Forming micro lines by etching of FR- 4 copper clad laminate with femtosecond laser

随着微电子技术飞速发展,电路板集成度的不断提高,产品研发周期的持续缩短,对于微细导电线路以及快速样板制作提出更迫切的需求。针对以上问题,本文采用飞秒激光进行覆铜板直接刻蚀的工艺研究,探索不同激光工艺参量(平均功率、扫描速度、扫描次数、离焦量、线间距)对刻蚀深度和底面粗糙度的影响规律。通过正交试验,探究各工艺参数对刻蚀深度和底面粗糙度的影响大小。结果表明:无论是以刻蚀深度还是以刻蚀粗糙度为加工质量的衡量指标,都是扫描次数的影响最大,扫描速度的影响最小。此外,通过综合平衡法得到最优工艺参数。利用飞秒激光冷加工和选择性刻蚀的特性,实现FR-4覆铜板表面线宽50μm、线间距20μm的微细线路高质量刻蚀加工。

With the rapid development of microelectronics,the integration of PCB keeps improving and the R&D period of the products continues shortening,leads to the increasingly urgent demands for micro conductive lines and rapid template production.To solve the above problems,a study on the direct etching of copper clad laminate by femtosecond laser is performed in this paper,the effect of femtosecond laser processing parameters(such as average power,scanning speed,scanning times,defocusing amount and line spa)on the laser processing quality of copper clad laminate are researched.The influence of processing parameters on etching depth and bottom roughness is explored through orthogonal test.The results shows that the influence of the scanning times is the greatest and the scanning speed is the smallest no matter the etching depth or the etching roughness is considered as the measure index.In addition,the optimum processing parameters are obtained by the comprehensive balance method.Finally conductive lines with a width of 50μm and a line spacing of 20μm are produced on FR-4 copper clad laminate with the cold processing and selective etching characteristics of femtosecond laser.