挠性多层线路板孔金属化技术研究

【作者】 霍彩红；

【导师】 何为； 何波；

【作者基本信息】 电子科技大学 ， 应用化学， 2005， 硕士

【摘要】 孔金属化工艺是一个贯穿整个FPCB(挠性印制线路板)生产的关键工艺,包括钻孔、去钻污、化学镀铜、电镀铜等工艺,由于工序长,步骤多,若是处理不好,就会造成产品合格率极低,产生很大浪费。以前主要生产单面板和双面板,孔金属化工艺还比较容易处理。近年来随着电子产品向着小巧、轻薄、短小、便于携带等方向的发展,对FPCB 的需求越来越大,得到快速发展,由于产品的层数越来越多,孔径越来越小,孔金属化工艺越来越难处理,成为整个挠性线路板生产的技术瓶颈。本文介绍了FPCB 的发展状况及前景,与孔金属化相关的工艺的原理,以及它们对产品质量的影响。主要针对孔金属化工艺中的去钻污工艺和沉铜工艺进行了研究。挠性印制线路板和刚性印制线路板的材料不同,刚性印制线路板主要是由环氧树脂玻璃布、特富龙等材料组成,这些材料产生的腻污可以用高锰酸钾来去除,然而挠性印制线路板主要是由聚酰亚胺和丙烯酸树脂等材料组成,这些材料在高锰酸钾溶液中会发生溶胀使多层板发生分层,因此无法用刚性印制线路板生产中使用的非常成熟的高锰酸钾去钻污法来对挠性印制线路板进行去钻污处理。通过查资料和总结实际生产的经验知道,当前对多层板去钻污最有效的方法是等离子清洗物理去钻污法和PI 调整溶液化学去钻污法。本文应用均匀设计法对等离子清洗去钻污工艺进行了研究,得到了因素对清洗效果的非线性回归方程,经过试验验证了回归方程的正确性。并以蚀刻速率为参考,分析了在对聚酰亚胺材料的清洗蚀刻中,单个因素对等离子清洗蚀刻速率的影响规律。应用正交设计法对PI 调整去钻污工艺进行试验,得到了PI 调整液的最佳配比和工艺参数。以蚀刻速率为参考,聚酰亚胺为蚀刻材料,分析了单个因素对PI 调整蚀刻速率的影响规律。并采用此法对沉铜工艺进行了试验,得到了沉铜溶液的优化配方和工艺参数,并使的产品的合格率比原来提高了10%。通过小批量试产,对比了PI 调整和等离子清洗两种方法产品的成品率和耐热冲击力。发现经这两种方法清洗后的产品合格率比没有经清洗的产品合格率分别提高了16%和23%。新研制的PI 调整工艺和优化配比及工艺参数后的沉铜溶液已经被应用到更多还原

【Abstract】 The hole metallization which including Drill, Desmear, Nonelectrical plating,Electrical plating etc., is a key process in the manufacturing of the flexible printedcircuit (FPC). Because it is a process that is made up of many steps, if it was notwell done, the qualified rate of product will be very low. The single side and doublesides FPC are the main products in the market several years ago, the holemetallization process of the manufacturing of the single side and double sides FPCwas relatively easy to be done. The application of FPC can make electronic productssmaller, lighter, thinner, more exquisite and pocketable. In recent years, suchproductions become more and more popular, so the demand for FPC is expandingvery fast, the layers of FPC are increasing continuously, the diameter of the holebecome smaller and smaller. The hole metallization process become difficult to dealwith, it has became the bottleneck of the FPC manufacturaing.The development and prospect of FPC, the principle of the hole metallizationprocess, Influence of various process factor on product quality was introduced inthis paper. The desmear process and the nonelectrical copper plating process, whichwere the key processes, were studied and introduced in detail.Because the material of flexible printed circuit (FPC) is different from the rigidprinted circuit board(RPCB), RPCB is mainly based on materials , such as epoxyresin , glass cloth, PTFE (Polytetrafluoroethylene), etc. the smear that caused by thismaterials can be get rid of using Potassium permanganate.while FPC is mainlybased on materials, such as PI (Polyimide), polyacrylates, this material willexpansion and make the layers breakaway, So the smear caused by this materialcan’t be get rid of using Potassium permanganate. There are two effective method,they are PI adjust and plasma wash method, can be used to getting rid of this smearthrough reading references and summarizing actual experience at present.Useing Uniform Design we research the plasma etch process, receive betterprocess parameter and regression curve related with each factors, prove that theresult is correct in manufacturing. Regarding the etching speed as criteria, weanalyse the influence for etching speed on PI in each factor.Using Orthogonal test we research the PI adjust process, get best matching of更多还原