Method of cleaning solder pastes from a substrate with an aqueous cleaner
US5593504A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1995 |
| Grant date | Jan 14, 1997 |
| Priority date | — |
| Expiry date | Apr 26, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/3485
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Printing applicators such as metal stencils and screens used to apply solder paste to printed circuit boards are cleaned to remove accumulated solder paste therefrom by an aqueous alkaline salt cleaner. The aqueous cleaner of the present invention comprises alkaline salts such as alkali metal carbonates, a surfactant formulation which contains at least one nonionic surfactant, an alkali metal silicate corrosion inhibitor and stabilizers to maintain the components in aqueous solution. The cleaner of the present invention contains no VOCs and is an effective and safe replacement for alcohol solvents previously used to clean solder paste from screens and stencils.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.