Chip-type coil

• US 5,003,279 A
• Filed: 08/22/1988
• Issued: 03/26/1991
• Est. Priority Date: 01/06/1987
• Status: Expired due to Term

• Current Assignee: Master Lock Company LLC (Fortune Brands Innovations, Inc.)
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Nakano, Kiyoshi, Fujinaga, Ryuichi, Sasaki, Kiyomi, Morinaga, Tetsuya, Kaneko, Toshimi
• Primary Examiner(s): Kozma, Thomas J.
• Application Number:
  US07/246,827
• Time in Patent Office: 946 Days
• Field of Search: 361/405, 200/265, 439/886, 439/887, 439/931, 336/192, 336/84 C, 336/219, 336/83
• US Class Current: 336/192
• CPC Class Codes: H01F 27/292 Surface mounted devices

Abstract

A chip-type coil whose terminal electrodes are formed directly on a magnetic core and each comprise a mixture of electrically conductive material with insulating material, so that specific resistance of the terminal electrode can increase so as to reduce an eddy current flowing in the terminal electrode, thereby preventing Q-deterioration in the chip-type coil. Moreover, the chip-type coil is allowable of Q-deterioration caused by metal plating, thereby enabling the terminal electrodes to be applied with metal plating.

Claims

1. A chip-type coil having terminal electrodes formed directly on a magnetic core, a winding on said core, said winding being connected to said terminal electrodes, wherein each of said terminal electrodes is formed of a mixture containing an electrically conductive material and an insulating material selected from the group consisting of insulating oxides, nitrides and carbides.

2. A chip-type coil as set forth in claim 1, wherein said electrically conductive material is silver.

3. A chip-type coil as set forth in claim 1, wherein said insulating material is an insulating oxide.

4. A chip-type coil as set forth in claim 3, wherein said insulating oxide is selected from the group consisting of alumina, silica, titanium oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, zirconia and ferrite powder.

5. A chip-type coil as set forth in claim 1, wherein said insulating material is an insulating nitride.

6. A chip-type coil as set forth in claim 5, wherein said insulating nitride is selected from the group consisting of Si₃ N₄ and AlN.

7. A chip-type coil as set forth in claim 1, wherein said insulating material is an insulating carbide.

8. A chip-type coil as set forth in claim 7, wherein said insulating carbide is SiC.

9. A chip-type coil as set forth in claim 1, wherein said terminal electrodes are each applied on the surface thereof with metal plating.

10. A chip-type coil as set forth in claim 9, wherein said metal plating comprises a nickel layer and a tin layer.