Thin film coil and electronic device having the same
There are provided a thin film coil and an electronic device having the same, the thin film coil including a substrate; and a coil pattern including a first coil strand and a second coil strand formed on both surfaces of the substrate, respectively, wherein the first coil strand formed on one surface of the substrate includes at least one gyration path that passes through the other surface of the substrate and gyrates.
1. A coil substrate provided in a wireless power transmitter, wirelessly transmitting power, or in a wireless power receiver, wirelessly receiving power, the coil substrate comprising:
a substrate having a first surface and a second surface;
a first spiral pattern disposed on the first surface of the substrate, and having a partially disconnected spiral shape;
a second spiral pattern disposed on the second surface of the substrate, and having both ends electrically connected to the first spiral pattern; and
a lead-out pattern having an end connected to the first spiral pattern, and disposed on the first surface of the substrate to traverse a disconnected portion of the first spiral pattern from an inside of the first spiral pattern to an outside of the first spiral pattern,
wherein electrical connection of the first spiral pattern is maintained across the disconnected portion by a plurality of first vias that penetrate through the substrate to electrically connect to the second spiral pattern,
wherein a portion of the coil substrate, outside of the disconnected portion, includes the first spiral pattern overlapping the second spiral pattern and electrically insulated therebetween by the substrate.
2. The coil substrate of claim 1 , further comprising two first pads disposed on one surface of the first surface and the second surface of the substrate,
wherein one of the first pads is electrically connected to the lead-out pattern, and the other first pad is electrically connected to an end of at least one of the first spiral pattern and the second spiral pattern.
3. The coil substrate of claim 2 , further comprising:
at least one second pad disposed on the other surface of the first surface and the second surface of the substrate; and
a second via disposed between the first pad and the second pad to electrically connect the first and second pads to each other.
4. The coil substrate of claim 2 , further comprising a magnetic member portion disposed on the first surface over the first spiral pattern or disposed on the second surface of the substrate over the second spiral pattern.
5. The coil substrate of claim 4 , further comprising a metal sheet disposed on an external surface of the magnetic member portion.
6. The coil substrate of claim 4 , wherein the substrate is configured to have a protrusion portion that is at least partially not covered by the magnetic member portion, and the first pads are disposed on the protrusion portion of the substrate.
7. The coil substrate of claim 1 , further comprising a third via disposed in the substrate within an inner portion of the first spiral pattern, to electrically connect an end of the lead-out pattern to the second spiral pattern.
8. The coil substrate of claim 1 , wherein the first spiral pattern and the second spiral pattern are disposed on positions of two surfaces of the substrate, respectively, the positions corresponding to each other in a vertical direction.
9. The coil substrate of claim 1 , wherein both ends of the first spiral pattern are connected to both ends of the second spiral pattern, respectively.
10. The coil substrate of claim 1 , wherein the substrate is a circuit board.
11. The coil substrate of claim 10 , wherein the circuit board is a flexible printed circuit board (FPCB), thin printed circuit board (PCB), or thin film circuit board.
12. The coil substrate of claim 1 , wherein the first spiral pattern and the second spiral pattern collectively form a coil pattern with an AC resistance characteristic related to AC resistance characteristics of parallel connected twisted wire strands.
13. The coil substrate of claim 1 , wherein the first spiral pattern and the second spiral pattern collectively form a coil pattern with a reduced skin effect.
14. The coil substrate of claim 1 , wherein, in the lead-out pattern having the end connected to the first spiral pattern, the lead-out pattern has the end connected to an end of the first spiral pattern.
15. The coil substrate of claim 1 , wherein the first spiral pattern and the second spiral pattern are respective thin film conductor patterns.
16. The coil substrate of claim 1 , wherein the first spiral pattern is parallel to the second spiral pattern in the portion of the coil substrate outside of the disconnected portion.