Patent ID: 8314343

Claim:
An electronic part-incorporated multilayer substrate, comprising: a core formed from a metal or an organic material and formed with at least one hole capable of containing an electronic part; a bottom insulating resin layer formed on a bottom surface of the core; a top insulating resin layer formed on a top surface of the core; a wiring layer formed on a bottom surface of the bottom insulating resin layer and another wiring layer formed on a top surface of the top insulating resin layer; and the electronic part contained in the at least one hole, wherein the bottom insulating resin layer is formed by a first insulating resin layer and a second insulating resin layer; the second insulating resin layer is bonded to the bottom surface of the core, and the first insulating resin layer is formed on a bottom surface of the second insulating resin layer, the first insulating resin layer having a thickness such that insulation is maintained between the electronic part and the wiring layer and between the core and the wiring layer; the electronic part is mounted on a top surface of the second insulating resin layer, and at least a part of a bottom surface of the electronic part is bonded and secured to the top surface of the second insulating resin layer, by adhesion of the top surface of the second insulating resin layer, in the at least one hole, said at least one hole being filled with a resin which constitutes the top insulating resin layer and which contains a filler; the top insulating resin layer is formed by a third insulating resin layer and a fourth insulating resin layer; the fourth insulating resin layer includes the filler in an amount greater than that in the third insulating resin layer, the fourth insulation resin layer fills the at least one hole of the core such that the electronic part is surrounded and sealed by the resin; and the third insulating resin layer which has a thickness such that insulation is maintained between the another wiring layer and the electronic part, and the third insulating resin layer is formed on a top surface of the fourth insulating resin layer.