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:
Sep. 15, 1998
Filed:
Oct. 28, 1996
Takeshi Hosomi, Fujieda, JP;
Toyoaki Kishi, Fujieda, JP;
Tomoyoshi Honjoya, Fujieda, JP;
Sei Nakamichi, Fujieda, JP;
Masahiro Mitsui, Fujieda, JP;
Sumitomo Bakelite Company Limited, Tokyo, JP;
Abstract
A process for producing a multilayer printed circuit board which comprises coating a light and heat curable undercoating agent on an internal layer circuit board, irradiating the undercoating agent with active energy beams to make the same tack-free, then laminating thereto a metal foil having an insulating adhesive layer and subsequently heating the resulting assembly to integrally cure the same. When the undercoating agent is coated on an internal layer circuit board and irradiated with a light to be made tack-free, and thereto is laminated a copper foil having a thermosetting insulating adhesive by a rigid roll or the like, the undercoating agent is softened or fluidized and the surface is smoothened. When the resulting laminate is thereafter heated, the undercoating agent coated on the internal layer circuit board and the insulating adhesive coated on the copper foil are integrally cured. Since the insulating adhesive coated on the metal foil keeps the thickness, a multilayer printed circuit board having an excellent board thickness precision can be produced without depending on the percentage of the remaining copper foil in the internal layer.