Magnetic conductive NiFe alloys

Patent metadata

Field	Value
Publication number	US-11075026-B2
Application number	US-201916399924-A
Country	US
Kind code	B2
Filing date	Apr 30, 2019
Priority date	Jun 7, 2018
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

Embodiments herein describe techniques for a magnetic conductive device including a substrate, an under layer above the substrate, and a magnetic conductive layer including NiFe alloy formed on the under layer. A method for forming a magnetic conductive device includes forming a support stack including an under layer above a substrate, cleaning the support stack, and performing electrodeposition on the under layer by placing the support stack into a plating bath to form NiFe alloy on the under layer. The NiFe alloy includes Ni in a range of about 74% to about 84%, and Fe in a range of about 26% to about 16%. Other embodiments may be described and/or claimed.

First claim

What is claimed is:

1. A magnetic conductive device, comprising:
a substrate;
an under layer above the substrate; and
a magnetic conductive layer including NiFe alloy formed on the under layer, wherein the NiFe alloy includes Ni in a range of 74 wt. % to 84 wt. %, and Fe in a range of 26 wt. % to 16 wt. %, and where the NiFe alloy has a magnetic conductivity of 6M ohms/m to 9 M ohms/m and a peak magnetic permeability of 1500-2000.

2. The magnetic conductive device of claim 1 , wherein the under layer includes a material selected from copper, gold, silver, or platinum.

3. The magnetic conductive device of claim 1 , wherein the under layer has a thickness of 20 nm to 50 nm.

4. The magnetic conductive device of claim 1 , wherein the substrate has a thickness of 5 um to 15 um.

5. The magnetic conductive device of claim 1 , wherein the substrate includes polyethylene glycol, polyamide, polyethylene terephthalate (PET), or glass.

6. The magnetic conductive device of claim 1 , wherein the magnetic conductive layer has a thickness of 200 nm to 500 nm.

7. The magnetic conductive device of claim 1 , further comprising:
an adhesion layer between the substrate and the under layer.

8. The magnetic conductive device of claim 7 , wherein the adhesion layer includes Ti or Cr, and has a thickness of 5 nm to 20 nm.

9. A method for forming a magnetic conductive device, comprising:
forming a support stack including an under layer above a substrate;
cleaning the support stack;
performing electrodeposition on the under layer by placing the support stack into a plating bath to form NiFe alloy on the under layer, wherein the NiFe alloy includes Ni in a range of 74% to 84%, and Fe in a range of 26% to 16%; and
wherein the NiFe alloy has a magnetic conductivity of 6M ohms/m to 9 M ohms/m and a peak magnetic permeability of 1500-2000.

10. The method of claim 9 , wherein the plating bath includes a nickel source, an iron source, a weak acid, an antioxidant, a reducer, and a wetting agent.

11. The method of claim 10 , wherein the nickel source of the plating bath is NiSO4, the iron source of the plating bath is FeCl2, the weak acid of the plating bath is boric acid, the antioxidant is L-ascorbic acid, the reducer of the plating bath is Dimethylamine borane (DMAB), and the wetting agent of the plating bath is Sodium dodecyl sulfate (SDS).

12. The method of claim 9 , wherein the plating bath includes 0.1-0.2 M NiSO4, 0.001-0.010 M FeCl2, 10-20 g/L boric acid, 0.5-5 g/L L-ascorbic acid, 0.5-5 g/L DMAB, 0.01-1 g/L SDS, and 0-20 g/L NH4Cl.

13. The method of claim 9 , wherein reagents for the plating bath are dissolved in deionized water (DI), and wherein, for each liter of DI, the following reagents are dissolved:
0.1 M NiSO4;
0.005 M FeCl2;
10 g boric acid;
1 g L-ascorbic acid;
1 g DMAB; and
0.1 g SDS.

14. The method of claim 9 , wherein a pH value of the plating bath is in a range of 3 to 4.

15. The method of claim 9 , wherein the performing electrodeposition on the under layer to form the NiFe alloy includes performing electrodeposition under a constant current density supplied by a DC power supply.

16. The method of claim 15 , wherein the performing electrodeposition on the under layer includes performing electrodeposition under constant current density with an amount in a range of 1 mA/cm2 to 5 mA/cm2.

17. The method of claim 9 , wherein the support stack further includes an adhesion layer between the substrate and the under layer.

18. A magnetic flux channel antenna, comprising:
a permeable cylinder including a magnetic conductive device, wherein the magnetic conductive device includes
a substrate;
an under layer above the substrate; and
a magnetic conductive layer including NiFe alloy formed on the under layer, wherein the NiFe alloy includes Ni in a range of 74 wt. % to 84 wt. %, and Fe in a range of 26 wt. % to 16 wt. %, and where the NiFe alloy has a magnetic conductivity of 6M ohms/m to 9 M ohms/m and a peak magnetic permeability of 1500-2000.

19. The magnetic flux channel antenna of claim 18 , wherein:
the under layer includes a material selected from copper, gold, silver, or platinum;
the substrate includes polyethylene glycol, polyamide, polyethylene terephthalate (PET), or glass;
the magnetic conductive layer has a thickness of 200 to 500 nm;
the under layer has a thickness of 20 nm to 50 nm; and
the substrate has a thickness of 5 um to 15 um.

Assignees

• Univ Arizona State

Inventors

• Liu Minglu
• Sieradzki Karl
• Dowd Brandon
• Diaz Rodolfo E

Classifications

• C22C2202/02

  Magnetic · CPC title

• B32B15/08

  of synthetic resin · CPC title

• H01F41/26

  using electric currents {, e.g. electroplating} · CPC title

• H01F10/14

  containing iron or nickel ({H01F10/126} , H01F10/13, H01F10/16 take precedence) · CPC title

• H01F1/14716 Primary

  in the form of sheets · CPC title