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. 11, 2004
Filed:
Sep. 18, 2001
Yoshihiro Kawakita, Osaka, JP;
Daizo Andoh, Osaka, JP;
Fumio Echigo, Osaka, JP;
Tadashi Nakamura, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A circuit board including a desired number of electrically insulating layers and wiring layers laminated alternately, and an inner via hole for securing an electrical connection between the wiring layers by compressing and hardening a conductive paste including a conductive particle and a resin. In the electrically insulating layer, a porous sheet is provided a resin sheet at least one surface, and the porous sheet is not impregnated with a resin at least at a central portion. A through hole penetrating the electrically insulating layer in the direction of the thickness of the electrically insulating layer is filled with a conductive paste including a conductive particle and a resin, and pores that are present inside the porous sheet are filled with laminated resin. The average hole diameter of the pores inside the porous sheet may be smaller than the average particle size of the conductive particle. Thereby, it is possible to make the insulating layer of the circuit board securing the interlayer electrically connection by an inner via hole including a conductive paste to be homogenized and ultra-thin and improve the reliability of the connection of the inner via hole.