Bonding film for printed circuit boards
US5885723A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1997 |
| Grant date | Mar 23, 1999 |
| Priority date | — |
| Expiry date | Dec 19, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31725
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Provided is bonding film for printed circuit boards which is resistant to cracking even when bent with a small radius of curvature, has a sufficient mechanical strength even in its semi-cured state so that the handling may be facilitated, is not undesirably brittle and therefore does not produce undesired debris when cut, and is flexible and flame retardant at the same time. The bonding film may consist of (i) high polymer epoxy resin; (ii) denatured polyamide obtained by reacting epoxy resin and polyamide; (iii) polyfunctional epoxy resin; and (iv) curing agent. Preferably, the denatured polyamide includes a polyalkylene-glycol residue or a polycarbonate-diol residue. Preferably, the high polymer epoxy resin is produced by the polymerization of bifunctional epoxy resin and bifunctional phenol resin, and has a weight averaged molecular weight equal to 50,000 or higher.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.