聚酰亚胺基底金属薄膜激光刻蚀温度场分布

Temperature Distribution for Laser Etching of Metal Thin Films on Polyimide Substrate

为研究脉冲激光刻蚀聚酰亚胺基底镀金属薄膜过程,采用有限元软件COMSOL Multiphysics构建高斯脉冲激光辐照复合材料的2维非稳态物理模型,通过求解热传导方程计算不同功率激光辐照金属薄膜的温度场分布,讨论不同激光参数对刻蚀进程的影响。模拟结果表明:刻蚀深度主要受激光功率密度的影响,且随着金属薄膜厚度的增加,激光刻蚀深度先减小后保持不变。在刻蚀过程中,为了更好地保护基底,应选择大功率短脉宽的激光参数;由于铜薄膜比铝薄膜更难刻蚀,在铜薄膜的刻蚀过程中应选择较大功率密度的激光。结果有助于理解激光刻蚀过程,对实际刻蚀过程有一定的指导意义。

In order to study the pulse laser etching process of metal thin films on polyimide substrate,a twodimensional transient physical model of Gaussian distribution pulse laser irradiation in composite material is established with the finite element analysis software COMSOL Multiphysics.The temperature distribution of metal thin films is calculated under irradiation of pulse lasers with different powers by means of solving the thermal conduction equations.The influences of different laser parameters on etching process are discussed.Simulation results show that the ablation depth is mainly affected by the laser power density,and it decreases at first and then keeps constant with increase of metal film′s thickness.During the etching process,it is appropriate to choose laser parameters of higher power and shorter pulse width in order to well protect the substrate from damage.As copper film etching is much more difficult than aluminum film etching,higher laser power density should be selected for copper film etching.Results are instructive and helpful to understand the actual laser etching process.