Magnetic composites and methods of making and using

• US 20070102663A1
• Filed: 05/11/2006
• Published: 05/10/2007
• Est. Priority Date: 05/11/2005
• Status: Active Grant

• Current Assignee: Inframat Corporation
• Original Assignee: Inframat Corporation
• Inventors: Ma, Xinqing, Xiao, T., Zhang, Heng, Zhou, Junfeng
• Granted Patent: US 8,377,576 B2
• Time in Patent Office: Days
• US Class Current: 252/62.51C
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: H01F 1/0027 Thick magnetic films forming thick magnetic films H01F41/16
• CPC Class Codes: H01F 1/0054 Coated nanoparticles, e.g. nanoparticles coated with organic surfactant
• CPC Class Codes: H01F 1/0063 in a non-magnetic matrix, e.g. granular solids granular films H01F10/007
• CPC Class Codes: H01F 1/37 in a bonding agent
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 41/16 the magnetic material being applied in the form of particles, e.g. by serigraphy , to form thick magnetic films or precursors therefor H01F41/18 -H01F41/24 take precedence
• CPC Class Codes: H02M 3/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H05K 1/0233 Filters, inductors or a magnetic substance
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/0257 Nanoparticles inks comprising nanoparticles H05K1/097
• CPC Class Codes: H05K 2201/086 for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]
• CPC Class Codes: Y10T 428/32 Composite [nonstructural laminate] of inorganic material having metal-compound-containing layer and having defined magnetic layer

Abstract

Disclosed herein is a magnetic paste that generally includes a magnetic component and a liquid organic component. The magnetic component includes a plurality of discrete nanoparticles, a plurality of nanoparticle-containing assemblies, or both. Magnetic devices can be formed from the magnetic paste. Methods of making and using the magnetic paste are also described.

Claims

1. A magnetic paste, comprising:

a magnetic component and a liquid organic component, wherein the magnetic component comprises a plurality of discrete nanoparticles, a plurality of nanoparticle-containing assemblies, wherein each assembly of the plurality of nanoparticle-containing assemblies has an average longest dimension of about 0.5 to about 150 micrometers, or both.

2. The magnetic paste of claim 1, wherein an assembly of the plurality of nanoparticle-containing assemblies is a solid composite comprising a plurality of separate conductive nanoparticles dispersed in an insulating matrix.

3. The magnetic paste of claim 2, wherein a nanoparticle-nanoparticle separation distance is about 1 to about 100 nanometers.

4. The magnetic paste of claim 2, wherein the insulating matrix comprises a high dielectric material.

5. The magnetic paste of claim 2, wherein at least a portion of the separate conductive nanoparticles is coated with an insulating composition.

6. The magnetic paste of claim 1, wherein an assembly of the plurality of nanoparticle-containing assemblies is a microscale particle comprising a plurality of agglomerated nanoparticles.

7. The magnetic paste of claim 1, wherein the liquid organic component is an epoxy, a polyimide, a polystyrene, ethyl cellulose, or benzocyclobutene.

8. The magnetic paste of claim 1, wherein the magnetic component is multi-modal.

9. The magnetic paste of claim 1, wherein the magnetic component comprises greater than or equal to about 40 volume percent of the magnetic paste.

10. The magnetic paste of claim 1, wherein the magnetic component comprises about 40 to about 92 volume percent of the magnetic paste.

11. The magnetic paste of claim 1, wherein each assembly of the plurality of assemblies has a packing density greater than or equal to about 75 percent of a theoretical density.

12. The magnetic paste of claim 1, wherein each of the plurality of nanoparticle-containing assemblies are in direct contact with an other of the plurality of nanoparticle-containing assemblies.

13. The magnetic paste of claim 1, wherein each of the plurality of discrete nanoparticles has a nanoparticle-nanoparticle separation distance of about 1 to about 100 nanometers.

14. A magnetic device, comprising:

a magnetic component and a solid organic component, wherein the magnetic component comprises a plurality of discrete nanoparticles, a plurality of nanoparticle-containing assemblies, wherein each assembly of the plurality of nanoparticle-containing assemblies has an average longest dimension of about 0.5 to about 150 micrometers, or both.

15. The magnetic device of claim 14, wherein the magnetic device is a power converter, antenna, inductor, magnetic filter, radiofrequency component, wave circulator, cellular phone, broadband device, cable television, radar device, sensor, telemetry device, or implantable medical device.

16. The magnetic device of claim 14, further comprising a substrate onto which the magnetic component and the solid organic component are disposed.

17. The magnetic device of claim 16, wherein the substrate is a printed circuit board, silicon wafer, or a ceramic material.

18. The magnetic device of claim 14, wherein the magnetic device has a permeability greater than or equal to about 3 at a frequency greater than or equal to about 1 megahertz.

19. The magnetic device of claim 14, wherein the magnetic device has a permeability greater than or equal to about 10 at a frequency greater than or equal to about 1 megahertz.

20. The magnetic device of claim 14, wherein the magnetic device has a permitivity greater than or equal to about 3.

21. The magnetic device of claim 14, wherein the magnetic device has an inductance greater than or equal to about 0.4 microHenry.

22. The magnetic device of claim 14, wherein the magnetic device has an inductance greater than or equal to about 1 microHenry.

23. The magnetic device of claim 14, wherein the magnetic device has an inductance at least two times greater than for the magnetic device without the magnetic component.

24. The magnetic device of claim 14, wherein an assembly of the plurality of nanoparticle-containing assemblies is a solid composite comprising a plurality of separate conductive nanoparticles dispersed in an insulating matrix.

25. The magnetic device of claim 14, wherein an assembly of the plurality of nanoparticle-containing assemblies is a microscale particle comprising a plurality of agglomerated nanoparticles.

26. The magnetic device of claim 14, wherein each of the plurality of discrete nanoparticles has a nanoparticle-nanoparticle separation distance of about 1 to about 100 nanometers.

27. A power converter, comprising:

a substrate, wherein the substrate comprises a printed circuit board, silicon wafer, or a ceramic material; and

a film disposed on the substrate of the power converter, wherein the film comprises a magnetic component and a solid organic component, wherein the magnetic component comprises a plurality of discrete nanoparticles, a plurality of nanoparticle-containing assemblies, wherein each assembly of the plurality of nanoparticle-containing assemblies has an average longest dimension of about 0.5 to about 150 micrometers, or both.

28. The power converter of claim 27, wherein the power converter has a permeability greater than or equal to about 3 at a frequency greater than or equal to about 1 megahertz.

29. The power converter of claim 27, wherein an inductance of the power converter is greater than or equal to about 0.4 microHenry at a frequency greater than or equal to about 1 megahertz.

30. The power converter of claim 27, wherein an inductance of the power converter is at least two times greater than for the power converter without the film.

31. A transformer, comprising:

a substrate, wherein the substrate comprises a printed circuit board, silicon wafer, or a ceramic material; and

a film disposed on the substrate of the transformer, wherein the film comprises a magnetic component and a solid organic component, wherein the magnetic component comprises a plurality of discrete nanoparticles, a plurality of nanoparticle-containing assemblies, wherein each assembly of the plurality of nanoparticle-containing assemblies has an average longest dimension of about 0.5 to about 150 micrometers, or both.

32. The transformer of claim 31, wherein a permeability of the transformer is greater than or equal to about 3 at a frequency greater than or equal to about 1 megahertz.

33. The transformer of claim 31, wherein an inductance of the transformer is greater than or equal to about 0.4 microHenry at a frequency greater than or equal to about 1 megahertz.

34. The transformer of claim 31, wherein an inductance of the transformer is at least two times greater than for the transformer without the film.

35. An inductor, comprising:

a substrate, wherein the substrate comprises a printed circuit board, silicon wafer, or a ceramic material; and

a film disposed on the substrate of the inductor, wherein the film comprises a magnetic component and a solid organic component, wherein the magnetic component comprises a plurality of discrete nanoparticles, a plurality of nanoparticle-containing assemblies, wherein each assembly of the plurality of nanoparticle-containing assemblies has an average longest dimension of about 0.5 to about 150 micrometers, or both.

36. The inductor of claim 35, wherein an inductance of the inductor is at least two times greater than for the inductor without the film.

37. The inductor of claim 35, wherein a permeability of the inductor is greater than or equal to about 3 at a frequency greater than or equal to about 1 megahertz.

38. The inductor of claim 35, wherein the inductance of the inductor is greater than or equal to about 0.4 microHenry at a frequency greater than or equal to about 1 megahertz.

39. A method for making a magnetic paste, the method comprising:

combining a magnetic component and a liquid organic component, wherein the magnetic component comprises a plurality of discrete nanoparticles, a plurality of nanoparticle-containing assemblies, wherein each assembly of the plurality of nanoparticle-containing assemblies has an average longest dimension of about 0.5 to about 150 micrometers, or both.

40. A method for making a magnetic device, the method comprising:

combining a magnetic component and a liquid organic component to form a paste, wherein the magnetic component comprises a plurality of discrete nanoparticles, a plurality of nanoparticle-containing assemblies, wherein each assembly of the plurality of nanoparticle-containing assemblies has an average longest dimension of about 0.5 to about 150 micrometers, or both;

disposing the paste onto a substrate; and

solidifying the paste.