INDUCTOR AND METHOD FOR PRODUCING IT

• US 20080309443A1
• Filed: 06/09/2008
• Published: 12/18/2008
• Est. Priority Date: 06/08/2007
• Status: Abandoned Application

• Current Assignee: Citizen Electronics Company Limited
• Original Assignee: Citizen Electronics Company Limited
• Inventors: FURUYA, Masahiro
• Application Number:
  US12/135,825
• Publication Number:
  US 20080309443A1
• Time in Patent Office: Days
• US Class Current: 336/83
• CPC Class Codes: H01F 17/045 with core of cylindric geometry and coil wound along its longitudinal axis, i.e. rod or drum core
• CPC Class Codes: H01F 2017/048 with encapsulating core, e.g. made of resin and magnetic powder
• CPC Class Codes: H01F 41/127 Encapsulating or impregnating encapsulating coil and core H01F41/005
• CPC Class Codes: Y10T 29/49073 by assembling coil and core

Abstract

An inductor includes a coil formed by winding a metallic wire, terminal electrodes connected to the coil, a first resin which is configured to cover at least one portion of a peripheral side surface of the coil and contains a magnetic powder, and a second resin which does not contain the magnetic powder and is configured to seal the coil covered by the first resin. Thereby, it is possible to provide an inductor having a stable characteristic with an unchanging L value even when there is contact during mounting of the inductor or impact during use of an electronic device in which the inductor is installed.

Claims

1. An inductor, comprising:

a coil including a bobbin and a metallic wire wound on the bobbin;

ends of the metallic wire electrically connected to terminal electrodes;

a first resin containing magnetic powder and disposed on at least one position of a peripheral side surface of the coil; and

a second resin sealing at least the first resin.

2. The inductor according to claim 1,

wherein the magnetic powder includes ferrite powder.

3. The inductor according to claim 1,

wherein the bobbin is made of a magnetic material.

4. The inductor according to claim 1,

wherein opposite two positions of the peripheral side surface of the coil are covered by the first resin.

5. The inductor according to claim 1,

wherein the terminal electrodes are provided on a lead frame and the coil is disposed in the lead frame.

6. The inductor according to claim 1,

wherein the terminal electrodes are provided on a circuit board and the coil is disposed in the circuit board.

7. The inductor according to claim 1,

wherein the first resin is disposed around the peripheral side surface of the coil.

8. The inductor according to claim 1,

wherein the second resin is nonmagnetic.

9. The inductor according to claim 1,

wherein the first resin is provided on the wound metallic wire.

10. The inductor according to claim 1,

wherein the second resin constitutes a substantially square shape in top-plan view and seals at least the first resin.

11. A method for producing an inductor according to claim 1, the method comprising:

a process for attaching an adhesive material to a multiple-formed collective substrate including a plurality of sections of substrates each including a pair of terminal electrodes;

a process for mounting a plurality of bobbins each disposing in each section of the collective substrate;

a process for winding the metallic wire continually on each of the bobbins in each section of the collective substrate to form a collective coil;

a process for providing a first resin including magnetic powder and covering at least a part of a peripheral side surface of the coil with a first resin;

a process for sealing the coil covered by the first resin member with a second resin member in which a magnetic powder is not contained, to form a collective inductor; and

a process for cutting the collective inductor into a plurality of independent inductors.