Coil unit, method of manufacturing the same, and electronic instrument

• US 20080197960A1
• Filed: 02/19/2008
• Published: 08/21/2008
• Est. Priority Date: 02/20/2007
• Status: Active Grant

• Current Assignee: 138 East LCD Advancements Limited (Vector Capital Corporation)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Hasegawa, Minoru, Kuroda, Masao
• Granted Patent: US 8,169,286 B2
• Time in Patent Office: Days
• US Class Current: 336/110
• CPC Class Codes: H01F 27/22 Cooling by heat conduction through solid or powdered fillings
• CPC Class Codes: H01F 27/2871 Pancake coils
• CPC Class Codes: H01F 27/292 Surface mounted devices
• CPC Class Codes: H01F 27/306 Fastening or mounting coils or windings on core, casing or other support
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01F 41/04 for manufacturing coils coils for transformer or inductances H01F27/28
• CPC Class Codes: H05K 1/182 associated with components mounted in the printed circuit board, e.g. insert mounted components [IMC]
• CPC Class Codes: H05K 2201/086 for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: H05K 2201/1003 Non-printed inductor
• CPC Class Codes: H05K 2201/10462 Flat component oriented parallel to the PCB surface
• CPC Class Codes: H05K 2203/1311 Foil encapsulation, e.g. of mounted components
• CPC Class Codes: Y10T 29/49078 Laminated

Abstract

A coil unit includes a planar coil, a printed circuit board that includes a planar coil placement section that receives the planar coil, a protective sheet that is provided on a transmission side of the planar coil and protects the planar coil, and a magnetic sheet that is provided on a non-transmission side of the planar coil. The planar coil is placed in the planar coil placement section and is electrically connected to the printed circuit board. The planar coil placement section has a shape that corresponds to an external shape of the planar coil.

Claims

1. A coil unit comprising:

a planar coil having a transmission side and a non-transmission side, a printed circuit board that includes a planar coil placement section that receives the planar coil;

a protective sheet that is provided on the transmission side of the planar coil and protects the planar coil; and

a magnetic sheet that is provided on the non-transmission side of the planar coil,

the planar coil being placed in the planar coil placement section and electrically connected to the printed circuit board; and

the planar coil placement section having a shape that corresponds to an external shape of the planar coil.

2. The coil unit as defined in claim 1,

the planar coil having an air-core section;

and

an inner terminal of the planar coil having a coil inner terminal lead line that is provided over the non-transmission side of the planar coil.

3. The coil unit as defined in claim 2,

the protective sheet having a first positioning hole that is formed at a position corresponding to the air-core section of the planar coil.

4. The coil unit as defined in claim 1,

the protective sheet being a heat sink sheet that has a thermal conductivity of 1 W/mK or more.

5. The coil unit as defined in claim 1,

the printed circuit board having a lead line placement section that receives a lead line of each terminals of the planar coil;

and

the lead line placement section being continuous with the planar coil placement section.

6. The coil unit as defined in claim 1,

the printed circuit board having a second positioning hole;

and

the protective sheet having a third positioning hole that is formed at a position corresponding to the second positioning hole.

7. The coil unit as defined in claim 1,

a mounted circuit being provided on a non-transmission side of the printed circuit board.

8. The coil unit as defined in claim 7,

a common ground electrode surface being formed on a transmission side of the printed circuit board, the common ground electrode surface being electrically connected to the mounted circuit.

9. An electronic instrument comprising the coil unit as defined in claim 1.

10. A method of manufacturing a coil unit that includes a planar coil, the method comprising:

(A) placing a protective sheet on an assembly jig;

(B) placing a printed circuit board on the protective sheet, the printed circuit board having a planar coil placement section that has a shape corresponding to an external shape of the planar coil;

(C) placing the planar coil in the planar coil placement section; and

(D) placing a magnetic sheet on the printed circuit board and the planar coil.

11. The method as defined in claim 10,

the method further including electrically connecting a lead line of each terminals of the planar coil to a wire layer of the printed circuit board between the steps (C) and (D).

12. The method as defined in claim 10,

the method further including electrically connecting a lead line of each terminals of the planar coil to a wire layer of the printed circuit board after the step (D).

13. The method as defined in claim 10,

the planar coil being an air-core planar coil;

the protective sheet having a first positioning hole that is formed at a position corresponding to an air-core section of the planar coil;

the assembly jig having a first positioning protrusion;

the step (A) including inserting the first positioning protrusion into the first positioning hole to position the protective sheet; and

the step (C) including inserting the first positioning protrusion into the air-core section to position the planar coil.

14. The method as defined in claim 13,

a lead line of an inner terminal of the planar coil being provided on a side opposite to a side where the planar coil contacts with the protective sheet.

15. The method as defined in claim 13,

the first positioning protrusion being held on the assembly jig so that the first positioning protrusion can adjust a height of the first positioning protrusion.

16. The method as defined in claim 10,

the printed circuit board having a second positioning hole;

the protective sheet having a third positioning hole that is formed at a position corresponding to the second positioning hole;

the assembly jig having a second positioning protrusion;

the step (B) including inserting the second positioning protrusion into the second positioning hole to position the printed circuit board; and

the step (C) including inserting the second positioning protrusion into the third positioning hole to position the protective sheet.