Process for manufacturing a printed wiring board
US6212769A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1999 |
| Grant date | Apr 10, 2001 |
| Priority date | — |
| Expiry date | Jun 29, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49167
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention teaches a simplified process for fabricating high density printed wiring boards using a semi-additive process. A roughened copper foil is laminated to a dielectric substrate. The foil is subsequently removed from the dielectric to create a roughened, irregular surface on the dielectric substrate. Vertical angle through holes and blind holes are formed in the substrate. A uniform copper commoning layer is electrolessly plated to the roughened dielectric substrate and through holes. A photoresist is applied on the surface of the electroless plated layer and irradiated through a mask having printed circuit features. After developing the photoresist the uncovered electroless layer is electrolytically plated to create the final features and circuitry. After stripping the remaining photoresist the unplated electroless copper layer is etched to electronically isolate the copper features and circuitry lines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.