| 摘要 |
PROBLEM TO BE SOLVED: To form a silver plating film having excellent characteristics with an electroless plating soln. which does not contain cyanogen compds. and has good stability by making an aq. soln. contg. a water soluble silver compd. and a water soluble sulfur-contg. organic compd. having mobosulfide groups in the molecule to be acidic. SOLUTION: In an aq. soln. contg. a water soluble silver compd. and a water soluble sulfur-contg. organic compd. having two monosulfide groups in the molecule, pH is controlled to <=7 with acid to obtain a substitution type electroless silver plating soln. extremely good in bath stability. Preferably, the sulfur-contg. organic compd. has water soluble groups such as hydroxyl group, carboxyl group, sulfonic group, amino group, phosphonic group and mercapto group in the molecules, it is composed of a compd. in which two pieces of 1 to 8C hydrocarbon groups are present between two pieces of monosulfide groups or a salt thereof, and the concn. thereof is preferably controlled to 0.5 to 150 g/l. Moreover, the concn. of the water soluble silver compd. such as silver oxide is controlled to 0.01 to 20 g/l. If required, 1 to 150 g/l thiourea compounds are moreover added as a precipitation improving agent.
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