Sintered flux refers to a high-quality, efficient, energy-saving, and environmentally friendly flux. It refers to processing the prepared wet solder into the required particles, calcining them at a high temperature of 750-1000 ℃, and forming small particles to obtain sintered solder. This flux is smokeless, odorless, arc free, and splash free during welding. The production and manufacturing process has no environmental pollution, low energy consumption, and sufficient utilization of raw materials, which is in line with national industrial development policies.