Method of making a chip coil

• US 4,769,900 A
• Filed: 08/05/1987
• Issued: 09/13/1988
• Est. Priority Date: 06/05/1985
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Nishimura, Kazuya, Morinaga, Tetsuya, Hata, Yukio, Kaneko, Toshimi
• Primary Examiner(s): Kozma, Thomas J.
• Application Number:
  US07/083,930
• Time in Patent Office: 405 Days
• Field of Search: 336/83, 336/212, 336/233, 336/192, 336/221, 29/602 R, 29/605, 29/606, 29/607, 29/608
• US Class Current: 29/606
• CPC Class Codes: H01F 2017/048 with encapsulating core, e.g. made of resin and magnetic powder
• CPC Class Codes: H01F 27/292 Surface mounted devices
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/366 made of ferromagnetic material
• CPC Class Codes: H01F 41/0246 Manufacturing of magnetic circuits by moulding or by pressing powder magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36
• CPC Class Codes: Y10T 29/49073 by assembling coil and core
• CPC Class Codes: Y10T 29/49076 From comminuted material

Abstract

A chip coil which includes a bobbin, flange portions formed at opposite end portions of the bobbin, a wire wound around a barrel portion of the bobbin, and at least two counter-part blocks of magnetic particle-containing solid resin, disposed around the wound wire. The counter-part blocks of magnetic particle-containing solid resin are adapted to be fixed to each other into one combined unit.

Claims

1. A method of shielding a chip coil, said chip coil comprising a bobbin, flanges formed at opposite ends of said bobbin, and a wire wound around said bobbin between said flanges, the method comprising the steps of:

(a) forming at least two counterpart blocks comprising magnetic particle-containing solid resin;

(b) disposing said blocks about said bobbin, said blocks engaging each other so as to substantially surround said wire; and

(c) fixing said blocks to each other to form a combined unit;

wherein each of said counterpart blocks of magnetic particle-containing solid resin is formed by mixing magnetic particles selected from the group consisting of Mn-Zn and Ni-Zn magnetic particles into a resin selected from the group consisting of epoxy resin and silicone resin, in a mixing ratio of substantially 100 to 1900 parts of the magnetic particles to 100 parts of the resin, to form a composite material; and

wherein said composite material is prepared in a semi-hardened state and then preliminarily molded into a block having a shape which permits said block to engage the flanges and the wire wound on the bobbin.

2. A method as claimed in claim 1, further comprising the step of forming a pair of electrodes on opposite edge portions of one of said flanges, said wire having two ends, and each of said ends of said wire being connected to a respective one of said electrodes.

3. A method as claimed in claim 1, wherein the magnetic particles have particle diameters in the range of 1 to 250 microns.

4. A method as claimed in claim 1, wherein each of said counter-part blocks of magnetic particle-containing solid resin has a U-shaped cross section so as to substantially completely surround said wire, when combined into a combined unit, with the extreme ends of the U-shaped blocks in engagement with each other.

5. A method as claimed in claim 1, wherein each of said counter-part blocks of magnetic particle-containing solid resin has an L-shaped cross section so as to substantially completely surround said wire, when combined into a combined unit, with the extreme ends of the L-shaped blocks in engagement with each other.

6. A method as claimed in claim 1, wherein a first one of said counter-part blocks of magnetic particle-containing solid resin has a U-shaped cross section, and a second one of said counter-part blocks has a flat plate-like shape with an I-shaped cross section configured and dimensioned so that said first and second counter-part blocks substantially completely surround the wire, when combined into a combined unit, with the extreme ends of the U-shaped block in engagement with the extreme ends of the I-shaped block.

7. A method as claimed in claim 1, wherein said blocks are configured and dimensioned so as to engage said flanges, and thereby substantially completely surround said wire, when said blocks are formed into a combined unit.

8. A method as claimed in claim 7, wherein said combined unit is adhered to said flanges.

9. A method as claimed in claim 8, wherein said combined unit is adhered to said wire.

10. A method as claimed in claim 1, wherein said blocks are then heated, brought while hot into contact with each other as well as with the wire and flanges, and then hardened to form said combined unit.