Solder leveling technique
US4676426A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1986 |
| Grant date | Jun 30, 1987 |
| Priority date | — |
| Expiry date | Mar 10, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/1476
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of solder leveling in printed circuit boards or other circuitized substrates. Flux is first applied to the surface of the substrate to be soldered. Molten solder is then applied to the fluxed surface after which the soldered substrate is cooled to a temperature below 300.degree. F. Molten solder is then again applied to the previously soldered surface of the substrate. This last step results in leveling the solder first applied to the substrate, including removal of any solder balls which had been formed over recessed pins and flush filling of passage holes formed in the substrate. The method can be performed without regard to the surface condition of the substrate, the composition of flux and solder, whether the substrate is of the thin film type or of the thick film type, nor whether dip soldering or wave soldering techniques are used. The invention also incompasses the end product resulting from use of the method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.