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:
Jul. 25, 1995
Filed:
Jan. 05, 1993
Kunio Nishimura, Ibaraki, JP;
Tadashi Hirakawa, Suita, JP;
Teijin Limited, Osaka, JP;
Abstract
An epoxy resin-impregnated prepreg useful for the production of a copper foil-laminated board of a chip-on-board having a high heat resistance, high dimension stability and high silver migration-preventing property, comprises an aromatic polyamide fiber base material having 3.0% by weight or less of an equilibrium moisture content, 80 ppm or less of an extracted chlorine content and 50 ppm or less of an extracted sodium content, and an epoxy resin composition comprising an epoxy resin and a curing agent, containing 5 ppm or less of sodium and 600 ppm or less of chlorine and impregnated in the base material, said aromatic polyamide fibers having been produced by a wet spin-drawing process having a draw-washing procedure in which undrawn aromatic polyamide filaments are drawn at a draw ratio of 1.05 to 1.5, while forwarding the filaments through a hot water bath having a path length of 1 to 50 m and while flowing hot water at 30.degree. C. to 100.degree. C. through the bath in a counter direction against the forwarding direction of the filaments to effectively squeeze out impurities from the filaments.