Process for the elimination of dimensional changes in ceramic green sheets
US3953562A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 15, 1974 |
| Grant date | Apr 27, 1976 |
| Priority date | — |
| Expiry date | Jul 15, 1994 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/634
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Ceramic substrates used in the fabrication of electrical components are generally formed by casting a composition comprising ceramic, binder, solvent and optional wetting agent onto a support, removing the casting composition solvent to yield a ceramic green sheet and firing the ceramic green sheet at elevated temperatures. In such a process, internal stresses are generated in the ceramic green sheet after casting compositions solvent evaporation, which stresses cause dimensional changes in the ceramic green sheet with the passage of time and adversely effect critical component tolerances. The present invention provides a process for stabilizing ceramic green sheets against dimensional changes, which occur with the passage of time and/or upon screening the ceramic green sheet with metallurgical patterns, by contacting the ceramic green sheet, after casting composition solvent removal, with a solvent which softens the binder in the ceramic green sheet and permits stress relieving.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.