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:
Feb. 07, 2012
Filed:
Feb. 20, 2009
Hideaki Yoshimura, Kawasaki, JP;
Kenji Iida, Kawasaki, JP;
Tomoyuki Abe, Kawasaki, JP;
Yasutomo Maehara, Kawasaki, JP;
Shin Hirano, Kawasaki, JP;
Hideaki Yoshimura, Kawasaki, JP;
Kenji Iida, Kawasaki, JP;
Tomoyuki Abe, Kawasaki, JP;
Yasutomo Maehara, Kawasaki, JP;
Shin Hirano, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
Large-sized through holes are formed in a core layer of a printed wiring board. Large-sized vias are formed in the shape of a cylinder along the inward wall surfaces of the large-sized through holes located within a specific area. A filling material fills the inner space of the large-sized via. A small-sized through hole penetrates through the corresponding filling material along the longitudinal axis of the small-sized through hole. A small-sized via is formed in the shape of a cylinder along the inward wall surface of the small-sized through hole. The filling material and the core layer are uniformly distributed within the specific area in the in-plane direction of the core substrate. This results in suppression of uneven distribution of thermal stress in the core layer in the in-plane direction of the core layer.