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:
May. 17, 2022
Filed:
Jul. 19, 2017
Hitachi Chemical Company, Ltd., Tokyo, JP;
Aya Kasahara, Tokyo, JP;
Tetsurou Iwakura, Tokyo, JP;
Showa Denko Materials Co., Ltd., Tokyo, JP;
Abstract
A composite film for electronic device using high frequency band signals, which is low in dielectric tangent, excellent in embedding properties relative to unevenness of a circuit, etc., and excellent in surface smoothness, and has high adhesion to plated copper is provided; and a printed wiring board containing a cured material of the composite film for electronic device and a method of producing the printed wiring board are also provided. Specifically, the composite film for electronic device is a composite film for electronic device using high frequency band signals, including a layer A having a minimum melt viscosity at 80 to 150° C. of 100 to 4,000 Pa·s; and a layer B having a minimum melt viscosity at 80 to 150° C. of 50,000 Pa·s or more. The composite film for electronic device is low in thermal expansion properties and excellent in handling properties of film.