为了研究移动脉冲激光刻蚀单/双层金属/聚酰亚胺基复合材料的规律, 利用有限元方法建立了移动纳秒脉冲激光刻蚀的通用模型, 讨论了移动速度对激光刻蚀深度的影响, 分析了金属铝薄膜和双层金属膜在移动脉冲激光作用下的温度变化规律。结果表明, 当激光移动速率一定时, 刻蚀深度开始时不断增加, 但增加幅度逐渐减小, 刻蚀深度逐渐趋于一定值, 即达到最大刻蚀深度; 金属与基底材料界面处的温度变化相较于金属薄膜靠近光源处的在时间上有一定滞后, 基底温度在激光关闭后可继续上升; 刻蚀双层金属膜时, 下层选用较厚且热导率较大的金属薄膜有利于保护聚酰亚胺基底。

In order to study the laws of single- or double-layer metal/polyimide etched by movable pulse lasers, one general model of movable nanosecond pulse laser etching is built with the finite element method. The influence of laser movement speed on etching depth is discussed, and the law of temperature change of the metal Al thin films and double-layer metal thin films etched by movable pulse laser is analyzed. The results show that, with a certain movement speed, the etching depth increases at the beginning, then the increase rate slows down, and the etching depth approaches to one constant maximum value. The temperature change at the interface between the metal and the substrate material lags behind that of the metal thin film close to laser source, and the substrate temperature rises continually after turning off the laser. As for double-layer metal films, the choice of thicker bottom layer with a high thermal conductivity is helpful to protect the polyimide substrate.