Patent ID: 9012786
Filing Date: 2015-04-21
Classification: H01L,H05K,Y10T

Abstract:
1. A circuit board comprising a substrate which mainly comprises ceramics and an inner layer electrode which comprises a conductive material embedded inside said substrate, wherein: said substrate comprises at least one first dielectric layer which consists of a first dielectric and at least one second dielectric layer which consists of a second dielectric, said second dielectric contains 8 mass % or more of a glass net former component, at least one portion of said inner layer electrode has two principal surfaces which are approximately parallel to principal surfaces of said circuit board and a thickness of not less than 50 micrometers in a normal direction of the principal surfaces of said circuit board, on at least one of said two principal surfaces which said inner layer electrode has, said inner layer electrode and said second dielectric layer contact with each other, a ratio t/T of sum total thickness t of said second dielectric layer in contact with said inner layer electrode in a normal direction of the principal surface of said circuit board to sum total thickness T of said first dielectric layer in a normal direction of the principal surface of said circuit board is 0.1 or more, and said first dielectric layer, said second dielectric layer and said inner layer electrode are simultaneously sintered.