Micro-via processing of glass ceramic green sheet for multi-layer substrate by third harmonics light of Nd : YAG laser

We have investigated micro-via hole formation by laser ablation on a Glass Ceramic Green Sheet (GCGS) to be used as a multi-layer substrate for an ele ctronics device. Micro-via holes with a 50 mu m diameter and 200 mu m pitch in a 100 mu m-thick green sheet, which are the currently required specific ations, have been successfully created by third harmonic light from a Nd:YA G laser. The throughput of this technique is over 70 vias per second, which is more than ten times that of the conventional punching method. We confir med the practicality of this laser process for multi-layer glass ceramic de vices.