Patent ID: 8111954

Claim:
A module substrate comprising: a single layer core portion formed of the same material; a build-up layer formed on the single layer core portion and comprising a wiring pattern and an insulating layer; a driver component embedded in the single layer core portion; an optical transmission component including an optical waveguide disposed between a light-emitting element and a light receiving element, the optical waveguide being a different member than the core portion, the optical waveguide, light-emitting element and light receiving element being embedded in the single layer core portion, the optical transmission component being electrically connected to the driver component which is a different component than the optical transmission component; a mounting portion provided on an outermost layer of the build-up layer on which a semiconductor element is to be mounted, the mounting portion being electrically connected to the optical transmission component via the wiring pattern, wherein the mounting portion comprises a first mounting portion and a second mounting portion, and the optical transmission component is disposed between the first mounting portion and the second mounting portion; and a columnar shaped electrode extending through the core portion and electrically connecting the build-up layer.