| 摘要 |
PURPOSE:To reduce the title novel release soln. capable of selectively releasing the tin on a copper matrix by preparing the soln. consisting of thiourea, a halogon-substituted fatty carboxylic acid, a release accelerating agent. CONSTITUTION:The thiourea selected from thiourea, an alkyl thiourea (thiosemicarbazide, etc.) and an aromatic thiourea [1-phenyl-3-(2-thiazolyl)-2- thiourea, etc.], and at least one kind of compd. selected from a halogen- substituted fatty carboxylic acid (dichloroacetic acid, etc.) having at least one halogen atom, the same sulfonic acid, the same aromatic carboxylic acid (trichlorobenzoic acid, etc.) the same halogen-substituted aromatic sulfonic acid (trichloro benzene sulfonic acid, etc.), or their esters and salts, and the inorg. acid (hydrochloric acid, etc.) and/or org. acid (citric acid, etc.) for accelerating the release, as required, are dissolvent in specified amts. in water to prepare the release soln. The novel and useful release soln. capable of selectively releas ing the tin or tin alloy on a copper matrix is thus obtained. |
