Method for manufacturing solder product, solder, soldered component, printed wiring board, printed circuit board, wire, soldered product, flexible printed board, electronic component, method for manufacturing tin article, method for manufacturing tin intermediate product, tin intermediate product, and conductive member

A method for manufacturing a solder product, the method comprising:

• a heating step of heating and melting a raw material to obtain a molten metal, the raw material containing tin as a main component, a metal element other than lead as a secondary component, and a carboxylic acid having 10 to 20 carbons;
• a removing step of removing, from the molten metal set to a pre-filtration temperature from 230° C. to 260° C., solids having a diameter of more than 10 μm and present within the molten metal by filtering the solids with a filter having an aperture size of not more than 10 μm, wherein the filter is heated by a heater, and a post-filtration temperature of the filtered molten metal is 230° C. to 260° C.;
• and
• a cooling step of cooling and solidifying the molten metal with the solids removed therefrom and depositing the carboxylic acid at a surface of the solder product to form a surface layer.