Cleavable diepoxide for removable epoxy compositions
US5932682A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1995 |
| Grant date | Aug 3, 1999 |
| Priority date | — |
| Expiry date | Dec 19, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G59/42
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A cleavable epoxy resin composition suitable for encapsulating electronic chips and a method for making the composition comprises the cured reaction product of a diepoxide; a cyclic dicarboxylic anhydride curing agent mixture; a 1,3-diaza compound having two nitrogen atoms present with one nitrogen atom doubly bonded to the central carbon and singly bonded to one other carbon, and the other nitrogen atom singly bonded to the central carbon and singly bonded to another carbon and singly bonded to a hydrogen. The 1,3-diaza compound serves either as the sole catalyst or in combination with a tertiary amine catalyst different from the diaza compound. The composition may include an optional hydroxy functional compound capable of reacting with the cyclic anhydrides to form a half ester thereby initiating the reaction between the diepoxide and the cyclic dicarboxylic anhydride curing agent. The resin can be used for the encapsulation of electronic parts, but can be removed by a solvent. This feature allows electronic components to be recycled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.