Ferrite composition, ferrite plate, member for antenna element, and antenna element

Patent metadata

Field	Value
Publication number	US-9793608-B2
Application number	US-201414555159-A
Country	US
Kind code	B2
Filing date	Nov 26, 2014
Priority date	Dec 20, 2013
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

An object is to provide a ferrite composition suitable for an antenna element with a long communication distance in a high-frequency band (for example, 13.56 MHz), a ferrite plate formed of the ferrite composition, a magnetic member for an antenna element formed of the ferrite plate, and an antenna element provided with a member for an antenna element. A ferrite composition, wherein: main components contain, with Fe 2 O 3 conversion, 45.0-49.5 mol % of iron oxide, with CuO conversion, 4.0-16.0 mol % of copper oxide, with ZnO conversion, 19.0-25.0 mol % of zinc oxide, a remaining portion is constituted by nickel oxide, an inevitable impurity is removed with respect to the main components, and as accessory components, with TiO 2 conversion, 0.5-2 weight % of titanium oxide, with CoO conversion, 0.35-2 weight % of cobalt oxide are contained.

First claim

The invention claimed is:

1. A ferrite composition comprising:
iron oxide (Fe 2 O 3 ) in a range from 45.0 to 49.5 mol %;
nickel oxide (NiO) in a range from 9.5 to 32.0 mol %;
copper oxide (CuO) in a range from 4.0 to 16.0 mol %;
zinc oxide (ZnO) in a range from 19.0 to 25.0 mol %;
titanium oxide (TiO 2 ) in a range from 0.8 to 2.0 weight %; and
cobalt oxide (CoO) in a range from 0.35 to 2.0 weight %.

2. A ferrite plate formed of the ferrite composition of claim 1 .

3. A magnetic member for an antenna element comprising:
the ferrite plate of claim 2 ;
an adhesive layer arranged on a first surface of the ferrite plate; and
a protective layer arranged on a second surface of the ferrite plate that is opposite to the first surface,
wherein the ferrite plate is divided into pieces in a grid shape between the adhesive and protective layers.

4. An antenna element comprising:
the magnetic member of claim 3 ; and
an antenna coil disposed on a surface of the adhesive layer.

5. The antenna element of claim 4 , having a communication distance of 50.0 mm or higher.

6. The ferrite composition of claim 1 , wherein:
iron oxide (Fe 2 O 3 ) is in a range from 45.5 to 48.5 mol %;
nickel oxide (NiO) is in a range from 15.0 to 30.0 mol %;
copper oxide (CuO) is in a range from 5.6 to 14.8 mol %;
zinc oxide (ZnO) is in a range from 20.0 to 24.5 mol %;
titanium oxide (TiO 2 ) is in a range from 0.8 to 1.9 weight %; and
cobalt oxide (CoO) is in a range from 0.4 to 1.5 weight %.

7. The ferrite composition of claim 1 , wherein:
iron oxide (Fe 2 O 3 ) is in a range from 46.0 to 48.0 mol %;
nickel oxide (NiO) is in a range from 17.0 to 28.0 mol %;
copper oxide (CuO) is in a range from 6.8 to 12.0 mol %;
zinc oxide (ZnO) is in a range from 21.0 to 24.0 mol %;
titanium oxide (TiO 2 ) is in a range from 0.8 to 1.8 weight %; and
cobalt oxide (CoO) is in a range from 0.5 to 1.0 weight %.

8. The ferrite composition of claim 1 , having μ′ that is 165 or higher and μ′ that is 7 or lower.

9. A ferrite composition comprising:
iron oxide (Fe 2 O 3 ) in a range from 45.0 to 49.5 mol %;
nickel oxide (NiO) in a range from 9.5 to 32.0 mol %;
copper oxide (CuO) in a range from 4.0 to 16.0 mol %;
zinc oxide (ZnO) in a range from 19.0 to 25.0 mol %;
titanium oxide (TiO 2 ) in a range from 0.5 to 2.0 weight %; and
cobalt oxide (CoO) in a range from 1.0 to 2.0 weight %.

10. The ferrite composition of claim 9 , wherein:
iron oxide (Fe 2 O 3 ) is in a range from 45.5 to 48.5 mol %;
nickel oxide (NiO) is in a range from 15.0 to 30.0 mol %;
copper oxide (CuO) is in a range from 5.6 to 14.8 mol %;
zinc oxide (ZnO) is in a range from 20.0 to 24.5 mol %;
titanium oxide (TiO 2 ) is in a range from 0.6 to 1.9 weight %; and
cobalt oxide (CoO) is in a range from 1.0 to 1.5 weight %.

11. The ferrite composition of claim 9 , wherein:
iron oxide (Fe 2 O 3 ) is in a range from 46.0 to 48.0 mol %;
nickel oxide (NiO) is in a range from 17.0 to 28.0 mol %;
copper oxide (CuO) is in a range from 6.8 to 12.0 mol %;
zinc oxide (ZnO) is in a range from 21.0 to 24.0 mol %;
titanium oxide (TiO 2 ) is in a range from 0.7 to 1.8 weight %; and
cobalt oxide (CoO) is in a range from 1.0 to 1.5 weight %.

12. The ferrite composition of claim 9 , having μ′ that is 165 or higher and μ″ that is 7 or lower.

13. A ferrite plate formed of the ferrite composition of claim 9 .

14. A magnetic member for an antenna element comprising:
the ferrite plate of claim 13 ;
an adhesive layer arranged on a first surface of the ferrite plate; and
a protective layer arranged on a second surface of the ferrite plate that is opposite to the first surface,
wherein the ferrite plate is divided into pieces in a grid shape between the adhesive and protective layers.

15. An antenna element comprising:
the magnetic member of claim 14 ; and
an antenna coil disposed on a surface of the adhesive layer.

16. The antenna element of claim 15 , having a communication distance of 50.0 mm or higher.

Assignees

• Tdk Corp

Inventors

• Ishikura Tomokazu
• Takane Shin
• Asano Norizumi
• Kunitsuka Kosuke

Classifications

• C04B35/26

  based on ferrites · CPC title

• H01F1/344

  Ferrites, e.g. having a cubic spinel structure (X2+O)(Y23+O3), e.g. magnetite Fe3O4 · CPC title

• C04B2235/3279

  Nickel oxides, nickalates, or oxide-forming salts thereof · CPC title

• C04B2235/6562

  Heating rate · CPC title

• C04B2235/3284

  Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof · CPC title