LAMINATED MAGNETIC COMPONENT AND MANUFACTURE WITH SOFT MAGNETIC POWDER POLYMER COMPOSITE SHEETS

• US 20110260825A1
• Filed: 04/23/2010
• Published: 10/27/2011
• Est. Priority Date: 09/12/2006
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Cooper Technologies Company (Eaton Corporation PLC.)
• Inventors: Doljack, Frank Anthony, Kamath, Hundi Panduranga
• Granted Patent: US 9,589,716 B2
• Time in Patent Office: Days
• US Class Current: 336/221
• 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 27/24 Magnetic cores
• CPC Class Codes: H01F 27/292 Surface mounted devices
• CPC Class Codes: Y10T 29/49073 by assembling coil and core

Abstract

Miniaturized magnetic components for electronic circuit board applications include enhanced magnetic composite sheets facilitating increased direct current capacity and higher inductance values. The components may be manufactured using relatively simple and straightforward lamination processes.

Claims

1. A magnetic component comprising:

at least one conductive wire coil including a first lead, a second lead, and a plurality of turns between the first and second lead; and

at least one insulating, dielectric, and magnetic sheet comprising a composite mixture of soft magnetic powder particles with no shape anisotropy and a binder material, the composite being provided as a freestanding, solid sheet layer;

wherein the at least one insulating, dielectric, and magnetic sheets is laminated to the coil, thereby defining a monolithic core structure embedding the at least one coil.

2. The magnetic component of claim 1, wherein the binder material is one of a thermoplastic or thermoset resin.

3. The magnetic component of claim 2, wherein the resin is polymer based.

4. The magnetic component of claim 2, wherein the at least one insulating, dielectric, and magnetic sheet is laminated to the coil with at least one of heat and pressure.

5. The magnetic component of claim 1, wherein the magnetic powder particles comprise at least 90 percent by weight of the mixture in the at least one insulating, dielectric, and magnetic sheet.

6. The magnetic component of claim 1, wherein an effective magnetic permeability of the at least one insulating, dielectric, and magnetic sheet is at least 10.

7. The magnetic component of claim 1, wherein a density of the at least one insulating, dielectric, and magnetic sheet is at least 3.3 grams per cubic centimeter.

8. The magnetic component of claim 1, further comprising terminal tabs coupled to each of the first and second leads.

9. The magnetic component of claim 1, further comprising surface mount terminations coupled to the respective first and second leads.

10. The magnetic component of claim 1, further comprising a magnetic core piece separately provided from the at least one sheet, the plurality of turns extending about the magnetic core piece, and the at least one sheet being laminated to the coil and the magnetic core piece.

11. The magnetic component of claim 10, wherein the magnetic core piece comprises a first portion having a first radius and a second portion having a second radius different from the first radius, the second portion extending from the first portion and the plurality of turns extending about the second portion.

12. The magnetic component of claim 11, wherein the separately fabricated core piece comprises a drum core, and the wire coil is wound around the drum core.

13. The magnetic component of claim 1, wherein the component is a power inductor.

14. The magnetic component of claim 1,

wherein the at least one insulating, dielectric, and magnetic sheet comprises a first sheet and a second sheet, each of the first and second sheets comprising a composite mixture of soft magnetic powder particles with no shape anisotropy and a binder material, the composite being provided as a freestanding, solid sheet layer;

wherein the at least one coil is interposed between the first and second sheet, and

wherein the first and second sheets are laminated to the coil and to one another to embed the at least one coil in a monolithic core structure.

15. A magnetic component comprising:

first and second insulating, dielectric, and magnetic sheets;

at least one conductive wire coil including a first lead, a second lead, and a plurality of turns between the first and second lead;

wherein the at least one conductive coil is interposed between the first and second insulating, dielectric, and magnetic sheets;

wherein the first and second insulating, dielectric, and magnetic sheets are laminated to the coil to embed the coil therebetween and define a monolithic core structure without creating a physical gap; and

the first and second insulating, dielectric, and magnetic sheets each comprising;

a composite sheet including soft magnetic powder particles with no shape anisotropy and a polymer binder consisting of thermoplastic or thermoset resin which can be laminated with heat and pressure;

the composite being provided as a freestanding, solid sheet layer;

wherein a density of the composite is at least 3.3 grams per cubic centimeter;

wherein the magnetic powder particles comprise at least 90% by weight percent of the composite; and

wherein the effective magnetic permeability of the composite is at least 10.

16. The magnetic component of claim 15, further comprising a magnetic core piece separately provided from the first and second sheets, the plurality of turns extending about the magnetic core piece, and the first and second sheets being laminated to the coil and the separately fabricated core piece to form a monolithic core structure.

17. The magnetic component of claim 16, wherein the separately fabricated core piece comprise a first portion having a first radius and a second portion having a second radius different from the first radius, the second portion extending from the first portion and the plurality of turns extending about the second portion.

18. The magnetic component of claim 17, wherein the magnetic core piece comprises a drum core, the wire coil being wound around the drum core.

19. The magnetic component of claim 15, further comprising surface mount terminations.

20. The magnetic component of claim 19, wherein the component is a power inductor.

21. A magnetic component comprising:

first and second insulating, dielectric, and magnetic sheet each comprising a composite being provided as a freestanding, solid sheet layer;

at least one conductive wire coil including a first lead, a second lead, and a plurality of turns between the first and second lead;

a magnetic core piece separately provided from the first and second insulating, dielectric and magnetic sheets;

the plurality of turns extending about the magnetic core piece;

wherein the at least one conductive coil and the magnetic core piece is interposed between the first and second insulating, dielectric, and magnetic sheets;

wherein the first and second insulating, dielectric, and magnetic sheets are laminated to the coil and the magnetic core piece to embed the coil and the magnetic core piece and define a monolithic core structure without creating a physical gap; and

surface mount terminations connected to the first and second coil leads.

22. The magnetic component of claim 21, wherein the magnetic core piece comprise a first portion having a first radius and a second portion having a second radius different from the first radius, the second portion extending from the first portion and the plurality of turns extending about the second portion.

23. The magnetic component of claim 22, wherein the separately fabricated core piece comprises a drum core, and the wire coil is wound around the drum core.

24. The magnetic component of claim 21, wherein the composite comprises:

soft magnetic powder particles with no shape anisotropy; and

a polymer binder consisting of thermoplastic or thermoset resin which can be laminated with heat and pressure;

wherein a density of the composite is at least 3.3 grams per cubic centimeter

wherein the magnetic powder particles comprise at least 90% by weight of the composite; and

wherein the effective magnetic permeability of the composite is at least 10.

25. The component of claim 21, wherein the component is a power inductor.

26. A method of fabricating a magnetic component including a wire coil and at least one insulating, dielectric and magnetic sheet,

the method comprising:

assembling at least one wire coil with the at least one insulating, dielectric and magnetic sheet layer;

the at least one sheet comprising a composite provided as a freestanding, solid sheet layer, the composite including soft magnetic powder particles with no shape anisotropy; and

laminating the at least one insulating, dielectric, and magnetic sheet to the at least one wire coil, thereby forming a monolithic core structure embedding the coil therein without a physical gap.

27. The method of claim 26, wherein assembling at least one wire coil with the at least one sheet comprises interposing at least one wire coil with first and second insulating, dielectric, and magnetic sheets each being a composite provided as a freestanding, solid sheet layer, the composite in each sheet including soft magnetic powder particles with no shape anisotropy;

and

laminating the first and second insulating, dielectric, and magnetic sheets to the at least one wire coil, thereby forming a monolithic core structure embedding the coil therein without a physical gap.

28. The method of claim 26, further comprising providing surface mount terminations connected to the first and second leads.

29. The method of claim 26, wherein the coil includes at least one conductive wire coil including a first lead, a second lead, and a plurality of turns between the first and second lead and the component further includes a magnetic core piece separately provided from the at least one insulating, dielectric, and magnetic sheet, the method further comprising:

extending the plurality of turns around a portion of the magnetic core piece; and

laminating the at least one insulating, dielectric, and magnetic sheet to the coil and the magnetic core piece.

30. The method of claim 29, wherein extending the plurality of turns around a portion of the magnetic core piece comprises winding the coil around a drum core.

31. A product formed by the method of claim 26.

32. The product of claim 31, wherein the product is a power inductor.

33. The method of claim 26, wherein the composite further comprises:

a polymer binder consisting of thermoplastic or thermoset resin which can be laminated with heat and pressure;

wherein a density of the composite is at least 3.3 grams per cubic centimeter;

wherein the magnetic powder particles comprise at least 90% by weight of the composite; and

wherein the effective magnetic permeability of the composite is at least 10.

34. A product formed by the method of claim 33.

35. The product of claim 34, wherein the product is a power inductor.

36. A magnetic component comprising:

at least one conductive wire coil including a first lead, a second lead, and a plurality of turns between the first and second lead; and

a magnetic composite material defining a monolithic core structure embedding the at least one coil without creating a physical gap;

wherein the magnetic composite material includes metal powder particles with no shape anisotropy and a binder;

wherein a density of the composite is at least 3.3 grams per cubic centimeter;

wherein the metal powder particles comprise at least 90% by weight percent of the composite; and

wherein the effective magnetic permeability of the composite is at least 10.

37. The magnetic component of claim 36, wherein the monolithic core structure is formed from at least one insulating, dielectric, and magnetic sheet laminated to the at least one coil.

38. The magnetic component of claim 36, wherein the at least one sheet comprises first and second sheets, and the conductive coil is interposed between the first and second insulating, dielectric, and magnetic sheets.