Multi-layer wiring substrate, and process for producing the same
US5728470A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 1995 |
| Grant date | Mar 17, 1998 |
| Priority date | — |
| Expiry date | May 12, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/4676
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A multi-layer wiring substrate includes an insulating layer which is essentially formed of a silica sintered product, and a conductor layer formed on an upper surface of the insulating layer from an electrically conductive material. The multi-layer wiring substrate is produced by forming a green sheet from a starting powder such as an ultrafine powder of amorphous silica having an average particle size of several to tens nm, and firing or calcining the green sheet at a temperature of 800.degree. to 1,200.degree. C. in an atmosphere containing steam to provide a silica sintered product which is sintered to a sufficient extent and has a high strength. The starting powder has a composition which comprises 95.0 to 99.5% by weight of a fine silica powder, 0.05 to 5.0% by weight of an alkaline earth metal compound, or comprises 95.0 to 99.0% by weight of a fine silica powder and 1.0 to 5.0% by weight of B.sub.2 O.sub.3. The silica sintered product has a sufficiently high strength and a dielectric constant of 4.0 at 1 MHz.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.