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. 03, 2014
Filed:
Feb. 24, 2011
Masayoshi Kondo, Tokyo, JP;
Natsuki Makino, Tokyo, JP;
Daisuke Fujiwara, Tokyo, JP;
Yuka Ito, Tokyo, JP;
Masayoshi Kondo, Tokyo, JP;
Natsuki Makino, Tokyo, JP;
Daisuke Fujiwara, Tokyo, JP;
Yuka Ito, Tokyo, JP;
Sumitomo Bakelite Company, Ltd., Tokyo, JP;
Abstract
A circuit board () exhibits an average coefficient of thermal expansion (A) of the first insulating layer () in the direction along the substrate surface in a temperature range from 25 degrees C. to its glass transition point of equal to or higher than 3 ppm/degrees C. and equal to or lower than 30 ppm/degrees C. Further, an average coefficient of thermal expansion (B) of the second insulating layer () in the direction along the substrate surface in a temperature range from 25 degrees C. to its glass transition point is equivalent to an average coefficient of thermal expansion (C) of the third insulating layer () in the direction along the substrate surface in a temperature range from 25 degrees C. to its glass transition point. (B) and (C) are larger than (A), and a difference between (A) and (B) and a difference between (A) and (C) are equal to or higher than 5 ppm/degrees C. and equal to or lower than 35 ppm/degrees C.