Abstract
Copper is widely used as an electric wiring material in electric and electronic industries because of its high electrical conductivity. However, high thermal conductivity of copper leads to the rapid diffusion of heat, which results in difficulties in micro-welding. Therefore, micro-welding of copper by a pulsed green laser of 532nm was investigated to control the heat input in micro-spot. 1.0kW peak power at spot diameter less than 200μm could perform a keyhole welding of 1.0mm thickness copper plate. Penetration depth increased with decreasing the spot diameter and increasing the pulse duration. The porosities could be reduced by extending the pulse duration and controlling the pulse waveform.
