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:
Jun. 16, 2015
Filed:
Aug. 07, 2013
Ajinomoto Co., Inc., Tokyo, JP;
Seiichiro Ohashi, Kawasaki, JP;
Eiichi Hayashi, Kawasaki, JP;
Shigeo Nakamura, Kawasaki, JP;
Takaaki Yazawa, Nagano, JP;
Junichi Nakamura, Nagano, JP;
AJINOMOTO CO., INC., Tokyo, JP;
SHINKO ELECTRIC INDUSTRIES CO., LTD., Nagano-shi, JP;
Abstract
Multilayer printed wiring boards may be prepared by forming a via hole by laser irradiation in insulating layer formed by a prepreg, comprised of a glass cloth impregnated with a thermosetting resin composition, and subjecting the via hole to a glass etching treatment with a glass etching solution and then to a desmear treatment with an oxidizing agent solution. By such a process, etch back phenomenon and excessive protrusion of glass cloth from the wall surface of a via hole can be sufficiently suppressed, and a highly reliable via can be formed. Particularly, a highly reliable via can be formed in a small via hole having a top diameter of 75 μm or below.