| abstract |
(57) [Summary] (Modified) [Purpose] To improve the heat resistance and chemical resistance of preflux and the reflow solderability for mounting components on a printed wiring board. [Constitution] After pre-fluxing copper and a copper alloy using benzimidazole or a benzimidazole derivative represented by (Chemical formula 1) or benzimidazole or a benzimidazole derivative represented by (Chemical formula 2) , Oxidize. [Chemical 1] (However, R 1 is H or an alkyl group having 3 to 17 carbon atoms, R 2 is H or an alkyl group having 1 carbon atom, and n is 0 to 3) [Chemical formula 2] (However, R 3 is H or an alkyl group having 1 to 6 carbon atoms, R 4 is H or an alkyl group having 1 to 6 carbon atoms, R 5 is H or an alkyl group having 0 to 7 carbon atoms, where n is 0 to 3) |