Effects of CCL inorganic filler on hole performance in PCB drilling process

Purpose This paper aims to investigate and document the effects of copper-clad laminate (CCL) inorganic filler on the hole performance in printed circuit boards drilling process. Design/methodology/approach Drilling of brittle laminates can result in hole cracking, layer-to-layer delamination and drill-bit wear and tool breakage. Adding large amount of fillers not only shortens the life of the drilling tool but also affects the drilling properties significantly regarding hole quality. This paper introduces the influence of filler content, type, hardness, particle size and the compounding method in the manufacture of the CCL on the drilling performance. Findings The filler content, filler type, hardness of filler, particle size of filler and the compounding method used for the filler have a great influence on the drilling properties of CCL. The higher the filler content, the larger the particle size and the more the hardness of the filler, the worse the drilling properties. The combination of hard particles like silica with softer particles can improve the drilling performance of CCL. Originality/value The paper describes what affects the drilling performance of CCL and how this knowledge can be used to design CCL with good drilling performance.