WIRING BOARD WITH BUILT-IN ELECTRIC ELEMENT

PROBLEM TO BE SOLVED: To provide a wiring board with a built-in electric element excellent in reliability wherein an electric element of a capacitor or the like is built in an insulating substrate and even after the thermal treatment of reflow soldering or the like, connection reliability between the electric element and wiring circuit layers is excellent and a function of the electric element does not vary. SOLUTION: In a wiring board with the built-in electric element A wherein a plurality of wiring circuit layers 8, 9 and via hole conductors 10, 11 formed by filling the via holes with metal components are formed on and/or in the insulating substrate 1 containing at least an organic resin, and the electric element 3 of the capacitor or the like that has at least a pair of terminal electrodes 6a, 6b is built, the terminal electrodes 6a, 6b of the electric element 3 and the via hole conductors 10, 11 are directly connected and an intermetallic compound of Cu and Sn such as Cu3Sn, Cu6Sn5 or the like is allowed to exist in connection parts of the terminal electrodes 6a, 6b and the via hole conductors 10, 11.