Apparatus and methods for magnetic core inductors with biased permeability

• US 10,629,357 B2
• Filed: 03/05/2018
• Issued: 04/21/2020
• Est. Priority Date: 06/23/2014
• Status: Active Grant

• Current Assignee: Ferric Inc.
• Original Assignee: Ferric Inc.
• Inventors: Sturcken, Noah, Davies, Ryan, Wu, Hao
• Primary Examiner(s): Lian, Mang Tin Bik
• Application Number:
  US15/911,778
• Publication Number:
  US 20180268982A1
• Time in Patent Office: 778 Days
• Field of Search: 336229, 336220, 336221, 336232, 336123, 336183, 336218, 296021, 29605, 29606
• CPC Class Codes: H01F 1/14708 Fe-Ni based alloys pure Fe or Ni H01F1/14, H01F1/16 or H01F1/20
• CPC Class Codes: H01F 13/003 Methods and devices for magnetising permanent magnets permanent magnets H01F7/02
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 17/04 with magnetic core
• CPC Class Codes: H01F 17/062 Toroidal core with turns of coil around it
• CPC Class Codes: H01F 2017/0066 with a magnetic layer
• CPC Class Codes: H01F 27/24 Magnetic cores
• CPC Class Codes: H01F 27/255 made from particles H01F27/26 takes precedence
• CPC Class Codes: H01F 27/2823 Wires H01F27/2866 takes precedence
• CPC Class Codes: H01F 27/2895 Windings disposed upon ring cores
• CPC Class Codes: H01F 27/38 Auxiliary core members; Auxiliary coils or windings
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H01F 41/06 Coil winding
• CPC Class Codes: H01F 41/14 for applying magnetic films to substrates
• CPC Class Codes: H01L 28/10 Inductors

Abstract

Inductive elements comprising anisotropic media and biasing coils for magnetically biasing thereof and methods of manufacture and operation for use in applications such as microelectronics. Application of an electrical current through the bias coils generates a magnetic field that biases the magnetic material such that a desirable orientation of anisotropy is achieved throughout the magnetic core and enables modulation of the inductive response of the device. Electrical conductors coupled to interconnects are magnetically coupled to magnetic core layers to produce self and/or mutual inductors.

Claims

1. A method of fabricating an inductor assembly, comprising:

fabricating a magnetic core and an inductor coil that winds around the magnetic core on a first substrate, the magnetic core lying in a core plane, the inductor coil configured to generate an inductor magnetic field that passes through the magnetic core in a first direction parallel to the core plane;

providing relative movement between the first substrate and a second substrate having a bias coil disposed thereon such that the bias coil on the second substrate and the magnetic core on the first substrate are within range of one another; and

applying current in the bias coil to;

(i) generate a bias magnetic field that passes through the magnetic core in a second direction that is orthogonal to the first direction and (ii) generate heat to heat the magnetic core, to induce a permanent or semi-permanent orientation of anisotropy for the magnetic core.

2. The method of claim 1, wherein the relative movement between the first substrate and the second substrate result in a relative positioning thereof in which the first substrate and the second substrate are in contact with one another.

3. The method of claim 2, further comprising applying force to press at least one of the second substrate and the first substrate against the other.

4. The method of claim 1, wherein said applying current in the bias coil comprises:

applying at least 10 mA of current in the bias coil.

5. The method of claim 1, wherein the heat is generated for at least 15 minutes.

6. The method of claim 5, wherein the heat is generated for at least 15 minutes.

7. The method of claim 6, wherein the generated heat is sufficient to heat the magnetic core to a temperature greater than 200°

C.

8. The method of claim 1, wherein the generated heat is sufficient to heat the magnetic core to a temperature greater than 200°

C.

9. The method of claim 1, wherein said induce a permanent or semi-permanent orientation of anisotropy for the magnetic core comprises:

induce a permanent orientation of anisotropy for the magnetic core.

10. The method of claim 1, wherein said induce a permanent or semi-permanent orientation of anisotropy for the magnetic core comprises:

permanently or semi-permanently fix an easy axis of magnetization of the magnetic core parallel to the second direction.

11. The method of claim 10, wherein said permanently or semi-permanently fix an easy axis of magnetization of the magnetic core parallel to the second direction causes a hard axis of magnetization of the magnetic core to be permanently or semi-permanently oriented parallel to the first direction.

12. The method of claim 1, wherein said induce a permanent or semi-permanent orientation of anisotropy for the magnetic core comprises:

permanently fix an easy axis of magnetization of the magnetic core parallel to the second direction to cause a hard axis of magnetization of the magnetic core to be permanently oriented parallel to the first direction.