挠性电路板基板覆盖膜镭射开窗的工艺研究

Research on coverlay laser opening process for flexible circuit board

挠性电路板高密度元器件贴装需求,IC、电容、电阻密集分布,以及新能源项目超厚铜镂空板设计制约下,覆盖膜开窗+覆盖膜贴合对位工艺,以及阻焊开窗工艺,无法满足开窗设计的需求。本文章通过深入研究覆盖膜贴合以及镭射开窗工艺的机理,结合现实的激光焊盘开窗需求,提出了一种贴覆盖膜后基板上直接镭射的制作方法,以达到满足上述制作的需求。具体地,利用CO_(2)镭射碳化成孔、成窗的原理,按特定的加工路径使目标覆盖膜上烧蚀开窗,并通过等离子清洗等方式清洁镭射后开窗,成功开发了挠性线路板覆盖膜基板直接镭射开窗的工艺。

The demand for high-density component mounting,as well as the dense distribution of IC,capacitor,and resistor,and the design of ultra-thick copper hollow boards in new energy projects,cannot meet the requirements of window opening design due to the coverlay opening and coverlay attaching alignment process,as well as the resistance welding window opening process.This article proposes a method of direct laser production on bare flexible circuit board after coverlay attaching,based on in-depth research on the principles of coverlay attach and laser opening technology,combined with practical requirements for solder mask window opening,to meet the above production requirements.Specifically,by utilizing the principle of CO_(2)laser carbonization to form pores,the target coating film is ablated and window openings are made according to specific processing paths.After laser process,the openings are cleaned by plasma and other surface cleaning methods,successfully developing a direct laser coverlay opening process for flexible circuit board.