Coil unit and electronic apparatus using the same
A coil unit includes a coil formed by winding a coil wire, a wiring substrate, and a magnetic substance for receiving magnetic lines of force generated by the coil. The wiring substrate includes a connection terminal connected to both ends of the coil, an external connection terminal, and a wiring pattern for connecting the connection terminal and the external connection terminal. No circuit element other than the coil is mounted on the wiring substrate.
1. A coil unit, comprising:
a coil formed by winding a coil wire, the coil having a transmission surface and a non-transmission surface;
a drawing line that is connected to the coil;
a wiring substrate, the wiring substrate having a coil housing that defines a coil housing hole, the coil being housed in the coil housing, and a drawing line hole adjacent to the coil housing hole, the drawing line extending through the drawing line hole;
a magnetic substance for receiving magnetic lines of force generated by the coil; and
a spacer that is disposed between the non-transmission surface of the coil and the magnetic substrate, the spacer having a notch that receives the drawing line.
2. The coil unit according to claim 1 , the coil being a flat coil.
3. The coil unit according to claim 2 ,
the coil being an air core coil formed by winding the coil wire on a plane in a spiral fashion, the coil having an inner end, the inner end of the coil being drawn from the non-transmission surface of the coil.
4. The coil unit according to claim 1 , the magnetic substance being a multilayer body where a plurality of magnetic substances are layered.
5. The coil unit according to claim 1 , wherein the coil is in a first configuration in which the magnetic substance is a multilayer body, in which first and second magnetic substances having different magnetic permeabilities, wherein the coil in the first configuration has a first inductance and a first equivalent resistance.
6. The coil unit according to claim 5 , wherein:
the coil would have a second inductance and second equivalent resistance in a second alternative configuration in which the first magnetic substance is disposed alone,
the coil would have a third inductance and third equivalent resistance in a third alternative configuration in which the second magnetic substance is disposed alone,
the second equivalent resistance is smaller than the third equivalent resistance, and
the second inductance is smaller than the third inductance.
7. The coil unit according to claim 6 , wherein a first Q value of the coil of the coil unit, defining a ratio of the first inductance to the first equivalent resistance, is larger than a second Q value, defining a ratio of the second inductance to the second equivalent resistance of the coil and is larger than a third Q value, defining a ratio of the third inductance to the third equivalent resistance.
8. The coil unit according to claim 7 , the first magnetic substance being disposed between the coil wire and the second magnetic substance.
9. The coil unit according to claim 1 , further comprising:
a temperature detection element; and
a flexible substrate on which the temperature detection element being mounted, the flexible substrate being connected to the wiring substrate, wherein
the flexible substrate being interposed between the coil wire and the magnetic substance.
10. An electronic apparatus comprising:
an insertion part into which the coil unit according to claim 1 is to be inserted; and
a main body terminal to be connected to the external connection terminal of the coil unit.
11. The coil unit according to claim 1 , the coil housing defining an aperture that receives the coil, the coil housing and the coil having substantially the same thickness such that an entire surface of the coil and the coil housing are flush with the spacer.
12. The coil unit according to claim 1 , wherein the drawing line hole and the coil housing hole are formed in the same layer.