Process for fabricating multilayer printed circuits
US5289630A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1991 |
| Grant date | Mar 1, 1994 |
| Priority date | — |
| Expiry date | Oct 29, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49126
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
For attaining adhesion between copper circuitry innerlayers and pre-preg layers in a multilayer printed circuit, a conversion coating of copper oxide is provided on the metallic copper surfaces in a manner which develops an altered topography of the underlying metallic copper surfaces. Thereafter, a controlled dissolution and removal of a substantial amount of the copper oxide is effected, in a manner which does not adversely affect the already-developed topography of the underlying metallic copper, and such that the innerlayer, at the time of assembly with the pre-preg layers, has copper surfaces consisting of the topographically altered metallic copper and a relatively small amount of copper oxide thereon. Excellent bonding strengths are achieved with decreased incidence of pink ring formation as compared to conventional processes utilizing copper oxide for adhesion promotion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.