High-temperature lead-free soft solder and preparation method thereof

The invention relates to the technical field of brazing filler metal, and discloses high-temperature lead-free soft brazing filler metal and a preparation method thereof.The high-temperature lead-free soft brazing filler metal is prepared from, by weight, 1.2%-3.6% of Cu, 0.8%-1.5% of Sb, 0.01%-0.1% of Ni, 0.03%-0.9% of Zr, 0.12%-0.36% of Zn, 3%-5% of Si, 0.02%-0.06% of Ce and the balance Sn and a small amount of inevitable impurities; the high-temperature lead-free soft solder prepared through the method has excellent welding performance, the melting temperature ranges from 420 DEG C to 440 DEG C, melting of the solder in secondary reflow soldering can be effectively avoided, and meanwhile the situation that a welded circuit board is damaged due to the fact that the welding temperature is too high, and then the reliability of the welding performance is affected can be avoided. 本发明涉及钎料技术领域，且公开了一种高温无铅软钎料及其制备方法，按重量百分比计由以下成分制成：1.2-3.6％Cu、0.8-1.5％Sb、0.01-0.1％Ni、0.03-0.9％Zr、0.12-0.36％Zn、3-5％Si、0.02-0.06％Ce、余量为Sn及少