采用激光直接焊接的方法，研究网络滤波器的无铅化封装技术，通过3种不同的方式进行了实验研究和理论分析，获得了将网络滤波器中直径为0.10 mm的极细铜芯漆包线在不去除绝缘漆的情况下直接焊接到铝引脚上的方法和途径。结果表明：焊接时用激光照射铜芯漆包线，去除绝缘漆后再熔化高熔点的、流动性好的铜芯，熔化后的液态金属铜向下流动，包覆难于焊接的、流动性差、易氧化、易形成气孔等焊接缺陷的铝材引脚，然后再与铝发生溶解、扩散，最后形成良好焊点。这种不需去除绝缘漆的方法使焊接过程大大简化，且满足无铅化的要求；通过辅助电路，能在一定程度上提高焊接的可靠性，便于进行自动化。

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 take place between the liquid copper just flowing down and the aluminum just melting; the weld joint is formed after the liquid metal cools and solidifies. This method without removing the insulating paint of enameled wire simplifies the welding process greatly and meets the lead-free requirement. It can improve the reliability of laser welding to some extent and is convenient for automation with the help of auxiliary circuit.