a circuit board has an embedded electronic component such as an integrated circuit chip with a wafer level chip size package . a via hole extends through the electronic component . another via hole extends through the substrate or prepreg on which the electronic component is mounted inside the circuit board . conductors in the via holes enable a terminal on the surface of the electronic component to be electrically connected to a wiring pattern or another electronic component on the opposite side of the substrate or prepreg . routing the connection through the electronic component itself saves space and reduces the length of the connection .