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. 07, 2011
Filed:
Apr. 02, 2007
Fumio Echigo, Osaka, JP;
Shogo Hirai, Osaka, JP;
Tadashi Nakamura, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A multilayer printed wiring board is characterized in that the interlayer connection material in the via holes has a lower coefficient of thermal expansion in the thickness direction than the electrically insulating substrate made of insulating material; the interlayer connection is formed at a temperature higher than the operating temperature; and the interlayer connection material is larger in thickness than the interlayer connection material of the same wiring layer at normal temperature. This causes a difference in the coefficient of thermal expansion between the different materials in the thickness direction of the printed wiring board in the environment in which it is used resulting in high connection reliability.