| abstract |
(57) [Abstract] [Problem] Even with a Zn-based solder, it can be stored as a solder paste for a long period of time, retains the same or better performance even if the thixotropic agent is reduced, has little heat sagging, and is sticky even after printing after printing. Providing solder paste without lowering and increasing solder balls. SOLUTION: At least one selected from the group consisting of a resin component, an activator, a thixotropic agent, an alkanolamine, an aliphatic primary to tertiary amine, an aliphatic unsaturated amine, an alicyclic amine and an aromatic amine. In a soldering flux containing a pH adjuster and a solvent, a pH of 4 to 9.5, a flux for soldering, characterized by using a saturated or unsaturated carboxylic acid amide having a melting point of 110 ° C. or more as a thixotropic agent reducing agent, |