Laser structuring of fine line printed circuit boards

The move towards very small devices such as chip scale packages and flip chip assemblies is restrained by the density limitations of the conventional PCB technology. In most imaging processes used in PCB technology, it is difficult to get the pitch below 100 mum (4 mils) pitches. It is necessary to progress from old technologies to the new ones. One of an alternative to conventional imagining is new technology of laser structuring (LS). The LS technique is technology of creating a structure in resists (tin or organic coating) by laser direct ablation. After ablating the resist, the structure is etched and the resist is striped. The conference paper includes first experimental results of direct structuring of tin and organic coating to create masks for etching process. The target is to achieve line/spaces below 125 mum