| abstract |
PURPOSE: To provide the preflux having good solderability even after exposure to a high temp. without using a volatile solvent by incorporating a benzimidazole compd. as an effective component into the preflux. n CONSTITUTION: The compd. expressed by formula I (R is H or n=1 to 17 alkyl group) or formula II (n=0 to 3) is incorporated as the effective component at about 0.01 to 40% into the preflux for soldering of metals. Benzimidazole, 2-ethyl benzimidazole, etc., are used as the above-mentioned compd. and are used by dissolving the same in an aq. soln. of acetic acid, etc. The film formed on the surface of copper or copper alloy has the excellent heat resistance if this preflux is used. The preflux is thus effective for surface packaging of electronic parts on printed wiring boards. n COPYRIGHT: (C)1991,JPO&Japio |