Process for preparation printed circuit through-holes for metallization
US5032427A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 1989 |
| Grant date | Jul 16, 1991 |
| Priority date | — |
| Expiry date | Nov 3, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/122
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Disclosed herein is a process for preparing the surfaces of through-holes in printed circuit boards (especially multilayer printed circuit boards) for subsequent metallization, in which the through-hole surfaces are treated with a substantially water-immiscible organic liquid which acts upon the insulating substrate of the board, and preferably in the form of a substantially homogeneous, clear mixture comprised of the water-immiscible organic liquid, water, an alkali metal compound and a surfactant component, followed by treatment of the through-hole surfaces with an alkaline permanganate solution. The process can be used as a desmearing and/or etch-back process, a combined desmearing-conditioning process, or a conditioning process following a separate desmearing process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.