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:
Aug. 22, 2006
Filed:
May. 27, 2003
Tokihito Suwa, Hitachinaka, JP;
Haruo Akahoshi, Hitachi, JP;
Shingo Kumamoto, Yasugi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A multilayer circuit board having a high level of reliability in terms of electric connection against temperature changes caused by the actual operation of electronic equipment, a manufacturing process, a substrate for multilayer circuitry, and an electronic apparatus. The multilayer circuit board comprises a laminate of at least one insulating layer and at least one wiring layer, wherein the wiring layer is formed by a composite member comprising a first metal layer and a second metal layer formed on one or both sides of the first metal layer, the first metal layer having a smaller coefficient of thermal expansion than the second metal layer, the second metal layer having a higher electric conductivity than the first metal layer, wherein the insulating layer has a blind via-hole with a bottom provided by a surface of the second metal layer, the circuit board further comprising a layer-to-layer interconnection portion on the surface of the insulating layer and in the blind via-hole, wherein the layer-to-layer interconnection portion in the blind via-hole is formed in such a manner as to be in contact with the surface of the second metal layer.