1. High-purity, outstanding weldability, good infiltration. 2. after clean, artistic, welds, insulates, the resistance to be high, after the ion pollutes, the PCB board to weld lowly, remains extremely few. 3. good oxidation resistance, low tin dregs, economical cost. 4. The spot luminous, is full and is even. 5. the economy, can produce most reliable spots by the lowest soldering tin consumption.