SUBSTRATE WITH BUILT-IN FUNCTIONAL ELEMENT, MANUFACTURING METHOD OF SUBSTRATE WITH BUILT-IN FUNCTIONAL ELEMENT, AND CIRCUIT BOARD

摘要

Provided is a substrate with a built-in functional element, wherein via-hole density, especially via-hole density between wiring layers around the periphery of the functional element can be improved. The substrate with the built-in functional element comprises the functional element (1); and a reinforcement layer (3) that has a plurality of via holes (4), and that is comprised of a first insulation material having the functional element buried therein. The substrate with the built-in functional element has at least one via hole, among the via holes that face the functional element (1) in proximity, made to be a deformed via hole (9) having a planar side face at the side facing a side face of the functional element (1).