Method of manufacturing magnetic shielding block for wireless power chargers

• US 10,439,447 B2
• Filed: 10/14/2016
• Issued: 10/08/2019
• Est. Priority Date: 11/27/2015
• Status: Active Grant

• Current Assignee: Nera Innovations Limited (Atlantic IP Services Limited)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Lee, Yun Bok, Lee, Sang Won, Lim, Hyung Jun
• Primary Examiner(s): Vargot, Mathieu D
• Application Number:
  US15/294,271
• Publication Number:
  US 20170155288A1
• Time in Patent Office: 1,089 Days
• CPC Class Codes: G01R 31/1227 of components, parts or materials G01R31/1209, G01R31/1218, G01R31/18 take precedence; circuits therefor G01R31/14; testing vessels of electrodes G01R31/16
• CPC Class Codes: G01R 33/0076 Protection, e.g. with housings against stray fields
• CPC Class Codes: G01R 33/025 Compensating stray fields G01R33/0017 takes precedence
• CPC Class Codes: G01R 33/1223 Measuring permeability, i.e. permeameters G01R33/14 takes precedence
• CPC Class Codes: H01F 1/0306 Metals or alloys, e.g. LAVES phase alloys of the MgCu2-type H01F1/0304 takes precedence
• CPC Class Codes: H01F 1/26 by macromolecular organic substances
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/366 made of ferromagnetic material
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01F 41/02 for manufacturing cores, coils, or magnets H01F41/14 takes precedence; for dynamo-electric machines H02K15/00
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/23 characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H05K 9/0075 Magnetic shielding materials

Abstract

Embodiments provide a magnetic shield for wireless power chargers and a method of manufacturing the same. The method includes forming flake powder having flake-type particles, forming an oxide film by performing oxygen heat treatment on the surface of the flake powder, performing insulation treatment on the surface of the flake powder provided with the oxide film formed thereon, and producing a sendust block by mixing and melting the insulation-treated flake powder and insulative resin powder. Therefore, a magnetic shield having high insulation characteristics and magnetic permeability may be provided.

Claims

1. A method of manufacturing a magnetic shield comprising:

forming flake powder having flake particles;

forming an oxide film by performing oxygen heat treatment on the surface of the flake powder;

forming an insulation layer on the surface of the oxide film of the flake powder by applying a chemical additive to the surface of the oxide film; and

producing a sendust block by mixing and melting the insulation-treated flake powder and insulative resin powder,

wherein the sendust block is produced by mixing the insulation-treated flake powder and the insulative resin powder such that particles of the insulation-treated flake powder are spaced apart from each other and uniformly arranged in the sendust block, and then performing heat treatment so as to melt the insulative resin powder and form the magnetic shield.

2. The method according to claim 1, wherein formation of the flake powder includes:

producing soft magnetic metal alloy powder having spherical particles using water atomization or gas atomization; and

compressing the soft magnetic metal alloy powder.

3. The method according to claim 1, wherein the chemical additive includes at least one of phosphate, a lubricant, kaolin, talc, magnesium hydroxide, aluminum oxide (Al₂O₃), Zn-stearate, Mg-stearate and sodium silicate.

4. The method according to claim 1, further comprising:

performing an insulation test by applying AC current to the produced sendust block; and

upon judging that the sendust block fails the insulation test, performing insulating coating on the surface of the sendust block.

5. The method according to claim 4, further comprising:

measuring magnetic permeability of the sendust block; and

judging whether or not the sendust block passes inspection based on the measured magnetic permeability.

6. The method according to claim 1, wherein terminals are formed integrally with the sendust block.

7. The method according to claim 1, wherein the insulative resin powder is formed of a polyimide-based resin or a phenol-based resin.