Semi-additive circuitry with raised features using formed mandrels
US5207887A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1991 |
| Grant date | May 4, 1993 |
| Priority date | — |
| Expiry date | Aug 30, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/167
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit is produced by using a formed mandrel (10,12) and semi-additive techniques for creating circuit traces. A stainless steel mandrel (10) flash plated with copper (14) includes a depression (12) which will form a raised interconnection feature (24). Using a photolithographically formed pattern of photoresistive material (16) on the mandrel the selected pattern of circuit traces (18,20) and raised features (24) are electroplated onto the flash plated mandrel. After stripping the photoresist (16), a dielectric substrate (26) is laminated to the circuit traces, effectively encapsulating the traces on three sides. After removing the laminated circuit traces and dielectric from the mandrel the flash plated copper (14) is removed and the circuit covered with an insulation coverlay.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.