Preparation of photoformed plastic multistrate by via formation first
US4572764A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 13, 1984 |
| Grant date | Feb 25, 1986 |
| Priority date | — |
| Expiry date | Dec 13, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49204
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Process for preparing multilayer printed circuits comprising laminating to a substrate bearing a circuit pattern or electrically conductive surface a photosensitive layer which is tacky or becomes tacky upon exposure; exposing the laminate to actinic radiation through a via image related to the underlying circuit pattern, if present; optionally removing the removable via image of the photosensitive layer in either the exposed or unexposed areas, e.g., with a solvent or peeling apart by removal of a cover sheet, if present; laminating to the remaining tacky photosensitive layer a layer of a second photosensitive composition; exposing the laminate to actinic radiation through a registered image pattern of at least one overlying segment of the via image area and conductive circuit pattern to form an image surface having nontacky areas and removable circuit image areas; removing the removable circuit image areas of the photosensitive layer in the exposed or unexposed areas with a solvent therefor, or peeling apart by means of a cover sheet, if present, the removable via image areas of the lower photosensitive, if present, are removed by a solvent therefor; embedding finely divided mate…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.