Abstract
High-quality copper welding is particularly important for variable devices in next generation automotive application, for example, motor core, lithium-ion battery, power semiconductor devices. Conventional IR laser in not suitable for copper welding because of its low optical absorption ratio. On the other hand, optical absorption ratio of copper in 450 nm wavelength is 65%, which is highly effective for laser welding. I this paper, copper welding results by utilizing blue and IR hybrid system are described. Attention is paid to improvement of optical absorption ratio of IR laser by assistance of blue laser.
