Multilayer printed circuit board
US3934335A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 16, 1974 |
| Grant date | Jan 27, 1976 |
| Priority date | — |
| Expiry date | Oct 16, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49156
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Multilayer printed circuit board is fabricated by coating a suitable substrate, metal, plastic, paper, with a photosensitive coating, exposing the photosensitive coating to form a dielectric thereof, coating the dielectric layer with a coating of a photosensitive chemical solution, selectively imaging and developing the photosensitive coating to form a desired circuit pattern on the dielectric coating, forming a first layer of circuitry by coating the circuit pattern with a conducting material, coating the circuitry bearing layer with a second layer of photosensitive material, selectively exposing and developing the second layer of photosensitive material to form a dielectric with open windows to the first circuit layer, coating the second dielectric layer of the first circuitry with a coating of photosensitive chemical solution, selectively imaging and developing the coating of photosensitive chemical solution to form a circuit pattern and an interconnect pattern and forming a conductor layer of circuitry and interconnects, the interconnect metallization connecting the second circuitry layer with the first circuitry layer, repeating the process to form additional circuitry layers …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.