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:
Feb. 18, 1997
Filed:
Nov. 07, 1995
Katsuhiro Murata, Ohtsu, JP;
Mitsumasa Shibata, Kusatsu, JP;
Toru Hatakeyama, Kusatsu, JP;
Tadaaki Isono, Ohtsu, JP;
Nippon Graphite Industries Ltd., Ohtsu, JP;
Abstract
An adhesive is applied onto a flexible resistive film 1 and dried to form an adhesive layer 2. A metal foil 3 is contacted onto the layer 2, which is subjected to a heat and pressing treatment. The foil 3 is polished. An ultraviolet light curable ink is applied on the foil 3 and dried to form a first layer 4. A negative film is placed on or over the layer 4 and ultraviolet light is irradiated thereto through the film so that the layer 4 is cured. Uncured portions of the layer 4 is removed so that cured portions thereof remain and the foil 3 is exposed between the remaining cured portions. The metal foil 3 is subjected to an etching treatment to remove exposed portions of the foil 3 so that unexposed portions of the foil 3 remain and form conductors 3A. The cured portions of the layer 4 is removed from the conductors 3A. A metal plating film 5 is formed on each conductor 3A to form each electrical conductive circuit 9. An ultraviolet light curable ink is applied on the layer 2 and dried to form a second layer 7. Ultraviolet light is irradiated to the layer 7 through the film 1 so that the layer 7 is cured in gaps 6 between the circuits 9. Uncured portions of the layer 7 is removed so that the circuits 9 are exposed and cured portions of the layer 7 remain in the gaps 6. The cured portions of the layer 7 is subjected to a heat treatment. The resulting flexible circuit board comprises the film 1, the adhesive layer 2, the circuits 9 and cured films 8 filling the gaps 6.