LCP挠性覆铜板紫外激光去膜工艺分析

Removal of Liquid Crystal Polymer Flexible Copper-Clad Laminates Using Ultraviolet Laser

液晶聚合物(LCP)是一种液晶聚合物,作为基板材料在微波/毫米波电路中表现优良,在5G封装中获得了广泛的关注。采用紫外纳秒激光对LCP挠性覆铜板进行去膜加工试验,在200 kHz重复频率下,采用控制变量的方法,研究了不同激光功率、扫描速度和扫描层数对LCP材料去膜深度的影响。为了减小热影响对电子器件和柔性电路板的影响,结合LCP的特性和实际加工结果,进一步分析LCP基板边框处热影响区范围随激光参数的变化规律。试验结果表明,以低热影响加工为目标,当扫描层数为5,扫描速度为600 mm/s,激光平均功率为2.1 W时,均匀性较好,加工深度可达49.84µm,边框处热影响区较小,可达28.43µm。该试验结果为LCP基板在柔性电路封装中提供了理论基础。

Liquid crystal polymer(LCP)has gained attention in 5G packaging because of its excellent performance as a substrate material in microwave/millimeterwave circuits.In this study,ultraviolet nanosecond laser was used to conduct the film removal experiment on LCP flexible copper plate.At the repetition frequency of 200 kHz,the effect of different scanning layers,scanning speed,and average power on the film removal depth of LCP material was studied using the controlvariable method.To reduce the effect of heat on electronic devices and flexible circuit boards,the variation law of heatinfluence zone at the frame of LCP substrate with laser parameters was analyzed based on the LCP characteristics and actual processing results.The experimental results show that when the scanning layer number is five,the scanning speed is 600 mm/s,and the average power of excitation light is 2.1 W,the machining depth can reach 49.84µm,the uniformity is good,and the heat affected zone at the frame is small,reaching 28.43µm.The experimental results may provide a theoretical basis for LCP substrate in flexible circuit packaging.