Low temperature fired ceramics
US4749665A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1986 |
| Grant date | Jun 7, 1988 |
| Priority date | — |
| Expiry date | Oct 16, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K1/0306
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Partially crystallized ceramic articles is prepared by firing at low temperatures of 800.degree. to 1100.degree. C., a mixture consisting essentially of, (a) 40 to 50 wt. % of powdered, noncrystalline glass consisting essentially of 10 to 55 wt. % of at least one selected from the group consisting of CaO and MgO, 45 to 70 wt. % of SiO.sub.2, 0 to 30 wt. % of Al.sub.2 O.sub.3, 0 to 30% of B.sub.2 O.sub.3 and up to 10% impurities, the powder size of said glass being at least 4.0 m.sup.2 /g in terms of specific surface area measured by the BET Method; and (b) 60 to 50 wt. % of powdered Al.sub.2 O.sub.3 and the ceramic article is composed essentially of a noncrystallized glass phase, alumina and at least one of crystallized glass phase among anorthite, wollastonite, cordierite and mullite formed by partially crystallizing the glass (a). The ceramic articles exhibit a very high flexural strength well comparable with alumina substrate, together with greatly improved dielectric constant and thermal expansion and thus are especially useful in making multi-layer ceramic substrates for electronic applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.