US Patent 7858885 Circuit board structure

The present invention provides a circuit board structure, the circuit board structure consisting of a carrier board having a first surface and an opposed second surface, the carrier board being formed with at least one through hole penetrating the first and second surfaces; a conductive pillar formed in the through hole by electroplating; and a first circuit layer and a second circuit layer respectively formed on the first and second surfaces of the carrier board, the first and second circuit layers being electrically connected to the two end portions of the conductive pillar, thereby reducing spacing between adjacent conductive pillars of the carrier board and achieving high density circuit layout.