等离子体清洗在刚挠结合板加工中的应用

Application of plasma cleaning in manufacture of multilayer Rigid-flex Boards

由于介面连接信号传输以及板件结构稳定性等影响因素，刚挠结合板需要使用到混合材料结构。孔金属化制程中，各种材料化学性质不同，采用相同化学除胶的方式会对叠板中柔性材料造成咬蚀过大，影响通孔的质量和板件的可靠性、稳定性。等离子体清洗采用高真空、高频能源与混合活性气体流动等方式对板件进行除胶，可以有效的改善化学除胶咬蚀过大造成的镀层质量下降等问题，目前已较多地应用于刚挠结合板的加工中。本文通过实验，对刚挠结合板的除胶参数和除胶方式进行正交优化设计，确定最佳的加工工艺参数，提升刚挠结合板各层连接的可靠性。

It is necessary to utilize layered composite materials for rigid-flex board to ensure the signal transmission on interface and the stability of board structure. In the process of hole metallization, since the different chemical properties of dielectric materials, the flexible material（etc. PI） will be over etched in the desmear process, which impacts the quality of metallization of holes and the reliability or stability of boards. The over etching of flexible materials will be solved by introducing plasma cleaning instead of chemical desmear. The plasma cleaning, which involves high vacuum, high frequency energy and mixed active plasma flow, improves desmear quality of hole walls. In this article, the optimum processing parameters and method of plasma cleaning have been obtained by orthogonal optimization tests for promoting the reliability of layer interconnection.