Surface treating agent for copper or copper alloys
US5348590A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 31, 1993 |
| Grant date | Sep 20, 1994 |
| Priority date | — |
| Expiry date | Aug 31, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/0591
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A preflux for a printed circuit board is provided, and the preflux has an excellent heat resistance adapted to a method of surface mounting electronic parts on the printed circuit board, and it is highly operable and reliable. The preflux is comprised mainly of a 2-alkylbenzimidazole derivative having the general formula of ##STR1## wherein R.sup.1 and R.sup.2 may be identical with or different from each other and are hydrogen atom, a lower alkyl group or a halogen atom, and R.sup.3 is an alkyl group of three or more carbon atoms, and contains a chelating agent reacting with copper ions added thereto. Addition of a proper amount of the chelating agent to the preflux makes it easy to form a highly heat-resistant film of the preflux only on copper or copper alloy patterns without masking the printed contacts and joint land. The chelating agent reacts with copper ions and selected from the group consisting of ethylene diamine triacetic acid, diethylene triamine pentaacetic acid, nitrylotriacetic acid, iminodiacetic acid, 1,2-cyclohexanediamine tetraacetic acid and glycolether diamine tetraacetic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.