Method for producing printed circuit boards
US5665525A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 6, 1995 |
| Grant date | Sep 9, 1997 |
| Priority date | — |
| Expiry date | Oct 6, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2201/09845
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for producing printed circuit boards (PCB), wherein a base material of a PCB, having copper claddings respectively on its opposed faces, is subject to the following subsequent processing steps. Holes are punched in the base material and claddings. The copper claddings are cleaned and deburred by mechanical and/or chemical techniques. Using image transfer and etching techniques, a pattern is produced in the cladding layers that exposes surface portions and leaves cladding portions adjacent to the holes of the base material. A photoimageable polymer insulating layer is applied to the exposed surfaces of the PCB base material and to the remaining pattern of cladding. The PCB is subjected to exposure and development, which exposes selected portions of the cladding layers including cladding portions adjacent to the holes. The opposite faces of the PCB are subjected to an adhesion improvement and activation treatment necessary for chemical deposition of metal. Image transfer is performed using a second photoimageable and developable insulating layer, and then metallization is applied to the hole walls and cladding portions adjacent to the holes by chemical deposition. In this pr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.