High current, low profile inductor

• US 6,204,744 B1
• Filed: 11/03/1997
• Issued: 03/20/2001
• Est. Priority Date: 07/18/1995
• 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): MAI, ANH T
• Application Number:
  US08/963,224
• Time in Patent Office: 1,233 Days
• Field of Search: 336/200, 336/96, 336/233, 336/223, 336/83, 336/90, 333/81.R
• US Class Current: 336/83
• CPC Class Codes: H01F 17/04 with magnetic core
• CPC Class Codes: H01F 2017/046 helical coil made of flat wire, e.g. with smaller extension of wire cross section in the direction of the longitudinal axis
• CPC Class Codes: H01F 37/00 Fixed inductances not covered by group H01F17/00
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49071 by winding or coiling
• CPC Class Codes: Y10T 29/49076 From comminuted material
• CPC Class Codes: Y10T 29/4922 with molding of insulation

Abstract

A high current, low profile inductor includes a wire coil having an inter coil end and an outer coil end. A magnetic material completely surrounds the wire coil to form an inductor body. First and second leads connected to the inner coil end and the outer coil end respectively extend through the magnetic material to the exterior of the inductor body. The method of operation involves pressure molding the magnetic material around the wire coil.

Claims

1. A high current, low profile inductor (IHLP) comprising:

a conductive coil having an inner coil end, an outer coil end, a plurality of coil turns, and a hollow core;

a first conductive lead connected to said inner coil end;

a second conductive lead connected to said outer coil end;

an inductor body substantially free from ferrite materials and comprising a uniform mixture of first and second powdered iron particles, said first powdered iron particles and said second powdered iron particles having electrical characteristics different from one another;

said uniform mixture of said first and second iron particles completely surrounding and contacting all of said conductive coil and portions of said first and second conductive leads, and also completely filling said hollow core;

said first and second iron particles being pressure molded within said hollow core and around said conductive coil and said portions of said first and second leads so that said first and second powdered iron particles of said inductor body are substantially free from voids therein and are compressed tightly completely around and in contact with all portions of said conductive coil and said portions of said first and second leads without shorting out said coil or said leads.

2. A high current low profile inductor (IHLP) according to claim 1 wherein said uniform mixture of said inductor body further comprises a filler.

3. A high current low profile inductor (IHLP) according to claim 2 wherein said uniform mixture of said inductor body further comprises a resin.

4. A high current low profile inductor (IHLP) according to claim 3 wherein said uniform mixture of said inductor body further comprises a lubricant.

5. A high current low profile inductor (IHLP) according to claim 4 wherein said uniform mixture of said inductor body is comprised of the following approximate weight ratios:

1,000 grams each of said first and second powdered iron particles;

36 grams of said filler;

74 grams of said resin; and

0.3% by weight of said lubricant.

6. A high current low profile inductor (IHLP) according to claim 1 wherein said conductive coil includes an insulative coating thereon.

7. A high current low profile inductor (IHLP) according to claim 6 wherein said conductive coil further includes an adhesive materiel coated over said insulative coating for holding said conductive coil in a predetermined helical shape.

8. A high current low profile inductor (IHLP) according to claim 7 wherein said insulation material comprises H₃PO₄.

9. A high current low profile inductor (IHLP) according to claim 1 wherein said inductor body is formed by the process of applying compressive forces of from 15 to 20 tons per square inch to said uniform mixture during said compressing step.

10. A high current, low profile inductor (IHLP) comprising:

a conductive coil having an inner coil end, an outer coil end, a plurality of coil turns, and a hollow core;

a first conductive lead connected to said inner coil end;

a second conductive-lead connected to said outer coil end;

an inductor body substantially free from ferrite materials and comprising powdered iron particles;

said powdered iron materials completely surrounding and contacting all of said conductive coil and portions of said first and second conductive leads, and also completely filling said hollow core;

said powdered iron materials being pressure molded within said hollow core and around said conductive coil and said portions of said first and second leads so that said powdered iron particles of said inductor body are substantially free from voids therein and are compressed tightly completely around and in contact with all portions of said conductive coil and with said portions of said first and second leads without shorting out said coil or said leads.

11. A high current low profile inductor (IHLP) according to claim 10 and wherein said iron particles are in a uniform mixture comprising a filler, a resin, and a lubricant.

12. A high current low profile inductor (IHLP) according to claim 11 wherein said inductor body is formed by pressure molding of said powdered iron materials under compressive forces of from 15 to 20 tons per square inch.