Circuit board with wiring sealing filled holes
US6127025A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1998 |
| Grant date | Oct 3, 2000 |
| Priority date | — |
| Expiry date | Mar 10, 2018 |
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 deposited onto a sacrificial carrier and the filler material is heated to at least partially cure it. 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 peelable layer, sacrificial carrier and filler material remaining therebetween are peeled off the copper foil. 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 photoimagable dielectric over pads and conductors of the wiring layer. Holes are formed through the substrate and the photoimagable d…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.