Ceramic article having a high moisture proof
US4650923A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1985 |
| Grant date | Mar 17, 1987 |
| Priority date | — |
| Expiry date | May 31, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/15192
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In an article comprising a ceramic body fired at a comparatively low temperature and a circuit pattern attached to the body, the ceramic body is produced from a preselected composition comprising first powder of alumina and second powder of a vitreous material which comprises any one of MgO-Al.sub.2 O.sub.3 -SiO.sub.2, CaO-MgO-Al.sub.2 O.sub.3 -SiO.sub.2, CaO-Al.sub.2 O.sub.3 -SiO.sub.2 glass, CaO-Al.sub.2 O.sub.3 -SiO.sub.2 -B.sub.2 O.sub.3 glass, MgO-Al.sub.2 O.sub.3 -SiO.sub.2 -B.sub.2 O.sub.3 glass, and CaO-MgO-Al.sub.2 O.sub.3 SiO.sub.2 -B.sub.2 O.sub.3 glass. The ceramic body comprises coexistence of an alumina part, a noncrystallized part, and a crystallized part and exhibits an excellent moisture proof. The circuit pattern comprises an internal conductive pattern of Ag and an external conductive pattern of an alloy of Ag-Pd. A chromium component may be included in the internal and the external conductive patterns. External and internal resistor patterns are placed on and within the ceramic body with a high and a low precision. The internal resistor pattern can be adjusted by the use of a laser beam through a thin film included in the ceramic body.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.