Abstract: Direct laser welding was used to study the lead-free packaging of network filter through three different methods. The methods for direct laser welding of enameled copper wire with a diameter of 0.10 mm in network filter are obtained without removing the insulating paint of enameled wire. The results show that, as the laser irradiates the enameled wire of network filter, the insulating paint is wiped off; the copper core, which has a high melting temperature and good fluidity, is melted; the liquid copper whose temperature is higher than the melting temperature of aluminum flows down and coats the aluminum pin; the aluminum pin, which has many disadvantages such as poor fluidity, difficult to weld, easy oxidization, is coated by liquid copper and melts partly; mutual solution and diffusion