WIRING BOARD WITH BUILT-IN ELECTRIC ELEMENT

PROBLEM TO BE SOLVED: To obtain a wiring board in which an electric element such as a capacitor is built in an insulating substrate thereof, which has superior mountability and mounting reliability even when a semiconductor device or the like is mounted on the substrate surface by flip-chip bonding, and superior reliability of the connection between the built-in electric element and the wiring circuit layer provided to the wiring board. SOLUTION: The insulating substrate 1 comprises a layered structure of a first insulating layer 1a including a mixture of thermosetting resin and inorganic filler and a second insulating layer 1b including a fiber body impregnated with the thermosetting resin. The first insulating layer 1a builds the electric element into itself, the second insulating layer 1b is arranged on the top surface of the insulating substrate 1, and the difference of thermal expansion coefficient between the electric element and the first insulating layer 1a is equal to or less than 7×10-6/°C and the difference of thermal expansion coefficient between the first insulating layer 1a and the first insulating layer 1b is equal to or less than 8.6×10-6/°C. COPYRIGHT: (C)2004,JPO