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. 20, 2011
Filed:
Aug. 18, 2008
Toru Okazaki, Osaka, JP;
Hideo Suzuki, Osaka, JP;
Toru Okazaki, Osaka, JP;
Hideo Suzuki, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
The present invention provides a multilayer wiring board in which warpage during reflow soldering can be reduced even if there is no sufficient space for disposing a dummy pattern or if a dummy pattern cannot be disposed. A difference between the ratios of copper remaining in wiring layers causes a difference between the amounts of thermal expansion of the wiring layers. The fiber bundle content of at least one resin base material layer is made different from that of the other resin base material layers, to cause a difference between the amounts of thermal expansion of the resin base material layers. This difference between the amounts of thermal expansion of the resin base material layers is used to cancel the difference between the amounts of thermal expansion of the wiring layers. Thus, warpage of the board during reflow soldering is reduced.