Method of manufacturing a chip coil

• US 4,696,100 A
• Filed: 06/30/1986
• Issued: 09/29/1987
• Est. Priority Date: 02/21/1985
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Shida, Sankichi, Todoroki, Tsunehiko, Yamamoto, Hiromasa
• Primary Examiner(s): Hall, Carl E.
• Application Number:
  US06/882,567
• Time in Patent Office: 456 Days
• Field of Search: 336/65, 336/83, 336/96, 336/205, 336/221, 336/222, 336/177, 336/192, 336/233, 29/605 R, 29/606, 29/608
• US Class Current: 29/605
• 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 27/027 specially adapted for combination of signal type inductors or transformers with electronic circuits, e.g. mounting on printed circuit boards
• CPC Class Codes: H01F 41/02 for manufacturing cores, coils, or magnets H01F41/14 takes precedence; for dynamo-electric machines H02K15/00
• CPC Class Codes: H01F 41/10 Connecting leads to windings making electric connections in general H01R43/00
• CPC Class Codes: Y10T 29/49071 by winding or coiling
• CPC Class Codes: Y10T 29/49073 by assembling coil and core
• CPC Class Codes: Y10T 29/49076 From comminuted material

Abstract

A method of manufacturing a chip coil, including a coil element which includes a magnetic core, a winding wire, and internal terminal electrodes, a fired mass of magnetic material surrounding and encapsulating the coil element, and external terminal electrodes electrically connected to the internal terminal electrodes. The winding wire is coated with a heat-resistive electrically insulating film and is wound around the magnetic core. The internal terminal electrodes are electrically connected to opposite ends of the winding wire and are exposed to the exterior of the mass at opposite ends of the core where they are electrically connected to the external terminal electrodes.

Claims

1. A method of manufacturing a chip coil comprising the steps of:

winding a conductor wire coated with a heat-resistive insulating film around a magnetic core, and connecting first and second internal terminal electrodes to respective opposite ends of the conductor wire, thereby to produce a coil element;

surrounding the coil element with a protective coating of magnetic substance powder;

after said step of surrounding, firing the coil element and coating of magnetic substance powder to obtain a single sintered mass of magnetic substance completely embedding therein the coil element without any gaps between the coil element and the single sintered mass so as to cover the conductor wire with the mass of magnetic substance in intimate contact with the entire outer surface of the conductor wire;

exposing at least part of each of the first and second internal terminal electrodes; and

connecting first and second external terminal electrodes respectively with the first and second internal terminal electrodes at the exposed part thereof, thereby obtaining the chip coil.

2. The method according to claim 1, wherein said step of winding includes the step of winding around the magnetic core the conductor wire coated with a film of magnetic substance as the heat-resistive insulating film and further coated with a resin film on the film of magnetic substance.

3. The method according to claim 1, wherein the step of winding includes the step of winding around the magnetic core the conductor wire coated with a glass film as the heat-resistive insulating film.

4. The method according to claim 1, wherein said step of surrounding comprises the steps of embedding the coil element in a magnetic substance powder, and applying pressure to the magnetic substance powder.

5. The method according to claim 1, wherein said step of exposing ends of the first and second internal terminal electrodes comprises the step of polishing both ends of the single sintered mass of magnetic substance by barrel-polishing until the first and second internal terminal electrodes are at least partly exposed.