Stabilized spray displacement plating process
US5217751A · kind A · utility
21Cited by
9References
22Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 27, 1991 |
| Grant date | Jun 8, 1993 |
| Priority date | — |
| Expiry date | Nov 27, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/244
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An efficient spray displacement tin plating process of copper printed circuit innerlayers is disclosed for the manufacture of multilayer printed circuit boards. The displacement tin plating solution is stabilized and replenished by incorporating free tin metal in the plating solution reservoir. Unwanted tin(IV) ions which are produced by aerial oxidation during the spray process, are reacted with tin metal in the reservoir to produce sufficient tin(II) ions to compensate for losses due to plating, oxidation and the like. Not only is the plating bath stabilized, but its useful life is extended dramatically.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.