Manufacturing circuit board assemblies having filled vias
US5822856A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 1996 |
| Grant date | Oct 20, 1998 |
| Priority date | — |
| Expiry date | Jun 28, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249996
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Circuit boards are manufactured by forming a substrate with a dielectric surface, laminating a metal foil and a peelable film to the substrate, and forming holes in the substrate through the peelable film and foil. A filler material with an organic base may be filled with electroconductive particles or dielectric thermoconductive particles. The filler material is laminated onto the peelable film with sufficient heat and pressure to force the filler material to fill the holes. For thermoconductive filler the holes are filled sufficient for electrical connection through the holes. The filler material is abraded to the level of the foil and is then copper plated. The copper is patterned to form a wiring layer. A permanent dielectric photoresist layer is formed over the wiring layer and via holes are formed through the photoimageable dielectric over pads and conductors of the wiring layer. Holes are formed through the substrate and the photoimageable dielectric, walls of the via holes, and walls of the through holes are copper plated. The copper plating on the photoimageable dielectric is patterned of form an exterior wiring layer. Components and/or pins are attached to the surface of …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.