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.
1. A circuit board structure, comprising:
a carrier board having a first surface and a second surface opposed to the first surface, the carrier board having at least a through hole penetrating the first and second surfaces;
an electroplating-formed conductive pillar completely filling the through hole, wherein surfaces of two ends of the conductive pillar are flush with the first and second surfaces of the carrier board;
a first circuit layer and a second circuit layer respectively formed on the first and second surfaces of the carrier board and a part of surface, from side to interior thereof, of each of the two ends of the electroplating-formed conductive pillar, the width of circuits of the first and second circuit layers electrically connected to the partial surfaces of the ends of the electroplating-formed conductive pillar being smaller than a diameter of the at least a through hole; and
a conductive layer formed between the first surface and the first circuit layer, between the second surface and the second circuit layer, and between the two ends of the electroplating-formed conductive pillar and the first and second circuit layers, wherein each of the first and second circuit layers has the same pattern as the conductive layer.
2. The circuit board structure of claim 1 , wherein the carrier board is one of a dielectric board, a copper clad laminate, a double-layer circuit board and a multi-layer circuit board.
3. The circuit board structure of claim 1 , further comprising a conductive layer formed on the surface of the through hole.