Bonding inner layers in printed circuit board manufacture
US6074803A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1997 |
| Grant date | Jun 13, 2000 |
| Priority date | — |
| Expiry date | Nov 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/0571
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A process for manufacturing a multi-layer circuit board comprises applying a layer of a photo-resist to the conducting surface of an inner-layer and fixing the resin composition in a pre-selected pattern for example by exposing to UV radiation which results in polymerization in the exposed areas. After removing the non-fixed areas by developing in an aqueous developing solution and etching in an etching solution, the fixed areas of resin composition remain in place on the inner-layer and are directly adhered to the neighboring insulating layer in an adhesion step. The preferred resin compositions according to the invention comprise a first photo-polymerizable resin component having an acid number from 15 to 75, a second epoxy resin component having unreacted epoxy groups, and a photoinitator, the ratio or first to second resin components being at least 1:1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.