Flux and solder paste

• Main Authors: NAGAI, TOMOKO, ASAMI, AI, TAKAGI, KAZUYORI
• Format: Patent
• Language: Chinese; English
• Published: 16.10.2022
• Subjects: CHEMISTRY; CLADDING OR PLATING BY SOLDERING OR WELDING; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; SOLDERING OR UNSOLDERING; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS; WELDING; WORKING BY LASER BEAM

A flux comprising a base resin, an activator, a thixotropic agent, a solvent, and a solder bonding defect inhibitor, wherein: the solder bonding defect inhibitor is a copolymer including a structural unit represented by formula (1) and a structural unit represented by formula (2); the weight average molecular weight of the copolymer is 1000-100000; the amount of the solder bonding defect inhibitor with respect to the entirety of the flux is 1-25 mass%; in formula (1), R1 represents a straight chain, branched chain, or cyclic alkyl group that is saturated or unsaturated and has 1-24 carbon atoms, or a substituted or unsubstituted aryl group; in formula (2), R2 represents a group represented by formula (2-1); and, in formula (2-1), n represents an integer of 1-30, R21 represents a hydrogen atom or an alkyl group having 1-6 carbon atoms, and R22 represents a straight chain, branched chain, or cyclic alkylene group having 1-6 carbon atoms.