Ceramic substrates with highly conductive metal vias
US5340947A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1992 |
| Grant date | Aug 23, 1994 |
| Priority date | — |
| Expiry date | Jun 22, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/128
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A ceramic substrate is provided with filled via holes for electrical or thermal feedthrough to or from an electronic device, each via hole having at least one dimension from about 4 to about 50 mils. The via holes are filled with copper, silver or gold for high conductivity and the filling is without visible voids at a magnification of 1000 diameters. The filling is preferably hermetic and is achieved by first electrodepositing metal into the holes and extending therefrom as dumbbell shaped plugs and then heating the substrate to the melting point of the metal so that metal from the dumbbell ends enters the connecting portion within the via hole to seal any aperture therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.