Micro-Welding of Glass Substrate by YAG Laser – Effects of Substrate Temperature –

Abstract

This paper deals with micro-welding of glass substrates using a YAG laser to prevent cracks. In order to fuse the glass substrates precisely using a YAG laser, a new glass welding method was proposed and developed in the previous report. In the method, two glass plates were made to overlap and the welded area of the glass surface was coated with absorbent. The YAG laser irradiated the surface, and the laser was absorbed in the coated area only. Therefore, only the coated area can be welded and the glass surface is expected to be clear. However, in the previous report, some micro cracks generated by the thermal shock of the YAG laser appeared on the fused area of the glass substrates. In this study, it is proposed that pre-heating the substrates decreses the heat shock, producing a crack-free surface of the fused area. In the pre-heated welding experiments, the substrate temperature and laser power are changed, and the welding surface and welding strength are evaluated. It is clarified from the experiments, that the glass plates can be welded without a crack using pre-heated welding.