Process for photolithographing a thick layer of paste deposited on a substrate
US4711835A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 4, 1985 |
| Grant date | Dec 8, 1987 |
| Priority date | — |
| Expiry date | Dec 4, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/0783
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to electric circuits formed by depositing a thick layer of conductive, resistive or dielectric paste on a flat substrate. The thick layers are deposited using a squeegee or by silk screen printing. In this first case, the resolution of the patterns is at best 200 microns, limited by the mesh of the silk screen printing screens. For obtaining finer patterns, the thick layer is dried, then masted using a photoresist, whose patterns may have a resolution of 50 microns, with a space of 50 microns. The thick layer is then etched, in its parts not protected by the photoresist mask, using a mixture of organic solvents which have a differential solubility with respect to the thick layer and to the photoresist.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.