Embedded inductor element and chip package applying the same
An embedded inductor suitable for a wiring board is provided. The wiring board comprises a plurality of patterned conductive layers, at least an insulating layer, and a plurality of conductive vias. The insulating layer is disposed between the neighboring patterned conductive layers. Two of the patterned conductive layers are electrically connected to each other through one of the conductive vias. The embedded inductor comprises a conductive spiral structure and at least an insulating portion. The insulating portion is disposed in the insulating layer and adjacent to the conductive spiral structure. The dielectric constant of the insulating portion is lower than that of the insulating layer. A parasitic capacitance value generated from the operation of the embedded inductor of the present invention is lower. Accordingly, the resonant frequency and the quality factor of the embedded inductor are effectively improved.
1. An embedded inductor suitable for a wiring board, the wiring board comprising a plurality of patterned conductive layers, at least an insulating layer, and a plurality of conductive vias, wherein the insulating layer is disposed between the neighboring patterned conductive layers, two of the patterned conductive layers are electrically coupled to each other through one of the conductive vias, and the embedded inductor comprises:
a conductive spiral structure; and
at least an insulating portion disposed in the insulating layer, wherein the insulating portion is neighboring to the conductive spiral structure and vertically throughout the whole layers of the wiring board including the patterned conductive layers and the insulating layer.
2. The embedded inductor of claim 1 , wherein the conductive spiral structure comprises at least a conductive line, and the conductive line is formed by one of the patterned conductive layers.
3. The embedded inductor of claim 1 , wherein the insulating portion is disposed on the periphery of the conductive spiral structure.
4. The embedded inductor of claim 1 , wherein the insulating portion is disposed inside the conductive spiral structure.
5. The embedded inductor of claim 1 , wherein the insulating portion is disposed in at least a hole on the wiring board.
6. The embedded inductor of claim 1 , wherein the insulating portion is disposed in at least a slot on the wiring board.
7. The embedded inductor of claim 1 , wherein the material of the insulating portion includes air.
8. The embedded inductor of claim 1 , wherein the dielectric loss tangent of the insulating portion is lower than the dielectric loss tangent of the insulating layer.
9. The embedded inductor of claim 1 , wherein the dielectric constant of the insulating portion is lower than the dielectric constant of the insulating layer.
10. The embedded inductor of claim 1 , wherein the insulating portion is formed by drilling or etching the insulating layer.