Preflux coating method
US5374331A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 19, 1993 |
| Grant date | Dec 20, 1994 |
| Priority date | — |
| Expiry date | Mar 19, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/1509
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Method for pretreatment of the metallic surfaces such as conductive patterns on printed wiring boards to protect against oxidation and/or other contamination. Boards are passed through successive stations to perform the following operations at least upon the metallic surfaces of the boards: remove oily substances; microetch the conductive surfaces; form a protective monolayer with a solution compatible with soldering materials; remove excess protective coating by rinsing; air dry and infrared dry the protective coating; uniformly supply a preflux solution and dry the boards including clearing the preflux solution from any holes or openings within the boards; cool the boards to ambient temperature. Each step in which a solution or liquid is applied, is preferably followed by a rinse operation. The application and rinse operations are preferably separated from one another by a buffer zone. With the exception of the drying stages, the boards are advanced through all of the other stages in the process by rotatable rollers prevented from experiencing translational motion. The preflux solution is applied by three sets of rollers pairs for precoating, flooding, and thereafter regulating t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.