Effect of Power on the Hollow Phenomenon during Laser Sintering of Copper Nanoparticles

Experimental and finite element simulation have been carried out to study the hollow phenomenon during the laser sintering process of copper nanoparticles. Copper nanoparticles were prepared by liquid phase reduction method and coated on a glass substrate to perform laser sintering experiments. The effect of laser power on the sintered line width and hollow region were analyzed. A finite element simulation model was established using the Element Birth and Death method to simulate the dynamically changing thermal properties of copper during the sintering process. The laser sintering temperature field of the copper layer with a thickness of 50 um on a 16 x 5 x 2 mm glass substrate were simulated using the model at different laser powers. The results represent that the high laser power and the lateral heat conduction effect are the main factors causing the hollow phenomenon. This study provides a method to understand the temperature field and the formation of hollow region during the laser sintering process of metal nanoparticles.