The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 23, 1999
Filed:
Dec. 19, 1997
Atsushi Takahashi, Yuki, JP;
Shinji Ogi, Yuki, JP;
Koji Morita, Shimodate, JP;
Kazunori Yamamoto, Tsukuba, JP;
Ken Nanaumi, Shimodate, JP;
Kiyoshi Hirosawa, Ibaraki-ken, JP;
Akinari Kida, Tochigi-ken, JP;
Takao Hirayama, Ibaraki-ken, JP;
Toshihiko Ito, Ibaraki-ken, JP;
Hiroaki Hirakura, Ibaraki-ken, JP;
Hitachi Chemical Company, Ltd., Tokyo, JP;
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.