Inductor coil and method for making same

• US 7,034,645 B2
• Filed: 01/20/2005
• Issued: 04/25/2006
• Est. Priority Date: 03/16/1999
• Status: Expired due to Term

• Current Assignee: Vishay Dale Electronics (Vishay Intertechnology Incorporated)
• Original Assignee: Vishay Dale Electronics (Vishay Intertechnology Incorporated)
• Inventors: Shafer, Timothy M., Jelkin, Brett W.
• Primary Examiner(s): Nguyen, Tuyen T
• Application Number:
  US11/038,880
• Publication Number:
  US 20050122200A1
• Time in Patent Office: 460 Days
• Field of Search: 336/83, 336/96, 336/192, 336/200, 336/225, 336/232, 336/233, 296/021, 296/05, 29841-842, 29848-858
• US Class Current: 336/83
• CPC Class Codes: H01F 17/04 with magnetic core
• CPC Class Codes: H01F 2017/048 with encapsulating core, e.g. made of resin and magnetic powder
• CPC Class Codes: H01F 2027/2861 Coil formed by folding a blank
• 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 27/2847 Sheets; Strips H01F27/2866 takes precedence
• CPC Class Codes: H01F 27/292 Surface mounted devices
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

A high current, low profile inductor includes a conductor coil surrounded by magnetic material to form an inductor body. The inductor coil is formed from a flat plate which is cut into a sine-shaped configuration and then is folded in accordion fashion to create a helical coil.

Claims

1. A method for making an inductor comprising:

forming an inductor element having first and second inductor ends from an electrically conductive material;

creating first and second terminal ends for the inductor element either by attaching the first and second terminal ends to first and second inductor ends of the inductor element or by forming the first and second terminal ends from the first and second inductor ends of the inductor element;

making a mixture comprising a resin and a non-ferrite powdered magnetic material;

compressing the mixture of resin and powdered magnetic material without liquefying the resin tightly around the inductor element to create an inductor body;

the compressing step being accomplished without injection molding;

leaving the first and second terminal ends outside the inductor body during the compressing step.

2. A method for making an inductor comprising:

forming an inductor element comprising a coil having an open center and an outside surface, the coil also having and first and second coil ends;

making a dry mixture comprising a dry resin and an insulated dry powdered magnetic material;

compressing the dry mixture around the outside surface of the coil and within the open center of the coil to create an inductor body without liquefying the dry mixture, whereby the inductor body engages the coil both within the coil open center and also the coil outside surface.

3. The method of claim 2 wherein the step of making a dry mixture comprises leaving ferrite out of the mixture.

4. The method of claim 2 and further comprising leaving the first and second coil ends outside the inductor body during the compressing step.

5. The method of claim 2 and further comprising attaching first and second leads to the first and second coil ends before the compressing step and leaving the first and second leads outside the inductor body after the compressing step.

6. The method of claim 2 wherein the compressing step causes the inductor body to be a single integral body.

7. A method for making an inductor comprising:

forming an inductor element comprising a coil having an open center and an outside surface, the coil also having and first and second coil ends;

making a dry mixture comprising a dry resin, a filler, a lubricant and an insulated dry powdered magnetic material;

compressing the dry mixture around the outside surface of the coil and within the open center of the coil to create an inductor body without liquefying the dry mixture, whereby the inductor body engages the coil both within the coil open center and also the coil outside surface.