Patent ID: 8222747

Claim:
A multilayer wiring substrate mounted with an electronic component, comprising: an electronic component; a core material layer which has a first opening for accommodating the electronic component; a resin layer which is formed on one surface of the core material layer and which has a second opening greater than the first opening; a plurality of connection conductor sections which are provided around the first opening and within the second opening on the one surface of the core material layer; bonding wires for electrically connecting the electronic component to the connection conductor sections; a sealing resin filled into the first and second openings in order to seal the electronic component and the bonding wires; a wiring pattern formed on the sealing resin; and a second resin layer which is formed on the other surface of the core material layer and which has a third opening which is the same size as the first opening and which is brought into alignment with the first opening, wherein the electronic component is accommodated in an opening formed from the first and third openings.