Method for manufacturing printed circuit boards
US4943346A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 1, 1989 |
| Grant date | Jul 24, 1990 |
| Priority date | — |
| Expiry date | Sep 1, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49165
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for manufacturing printed circuit boards has a double etch process to form interconnection wiring. A metal layer is formed on the substrate. An etch resist layer is applied to the metal layer. The layer is selectively removed to allow for selective etching of the metal layer. A second etch resist layer is applied to the metal layer not previously etched. The side walls of the metal layer are also protected by the resist. The second etch resist layer is then selectively removed to allow for a second etching of the metal layer. After the second etching, the interconnection wiring remains in the desired pattern. The second etch resist layer, which may be tin, can be left on the wiring to improve component soldering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.