Medium-temperature solder

The invention discloses a medium-temperature welding flux, and particularly relates to a medium-temperature welding flux with the welding temperature of 220-240 DEG C. The medium-temperature welding flux comprises, by weight, 76-87% of raw materials, 6-12% of scaling powder and 2-12% of a porous carrier, the raw materials comprise tin and indium, and the porous carrier is mainly composed of polyvinyl alcohol spherical carrier particles. When the welding flux is used, the surface gloss of a welding spot is good, and the good acid-resistant and corrosion-resistant functions are achieved. The solder can effectively solve the technical problems of insufficient surface hardness, insufficient corrosion resistance of welding spots after use and the like of the existing lead-free solder. 本发明公开了一种中温焊料，尤其是焊接温度在220至240℃的中温焊料，按照重量百分比，焊料包括原料76～87％、助焊剂6～12％以及多孔载体2～12％，所述原料包括锡和铟，所述多孔载体主要由聚乙烯醇球形载体颗粒构成。本发明，在使用焊料时，焊点不仅表面光泽好，而且具有较好的耐酸、耐腐蚀的功能的。焊料可有效解决了目前无铅焊料由于表面硬度不够、使用后焊点耐腐蚀性不够的等技术问题。