Patent ID: 8064218

Claim:
A multilayer wiring board comprising a plurality of wiring sheets each having an internal wiring and a plurality of electrical insulating sheets wherein both of said wiring sheets and said electrical insulating sheets are arranged alternately in their thickness directions and wherein a plurality of electrodes for implementing an electronic component electrically connected to said internal wirings are formed on the surface of an uppermost electrical insulating sheet, said multilayer wiring board further comprising: a plurality of auxiliary electrodes corresponding to said electrodes for implementing said electronic component and provided on said wiring sheet located directly under said uppermost electrical insulating sheet so as to be electrically connected to said internal wirings connected to said electrodes for implementing said electronic component; and a conductive portion penetrating the multilayer wiring board in the thickness direction, said conductive portion electrically connecting said auxiliary electrodes to said internal wirings, wherein said auxiliary electrodes are provided directly under said electrodes for implementing said electronic component corresponding to said auxiliary electrodes, said auxiliary electrodes being used in place of said electrodes for implementing said electronic component in case of failure or breakage of said electrodes for implementing said electronic component, by electrically connecting said auxiliary electrodes to said internal wirings with said conductive portion.