Ferrite sintered plate and ferrite sintered sheet

Patent metadata

Field	Value
Publication number	US-10714247-B2
Application number	US-201515312288-A
Country	US
Kind code	B2
Filing date	May 21, 2015
Priority date	May 22, 2014
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

Abstract

The present invention relates to a ferrite sintered plate having a composition comprising 47 to 50 mol % of Fe 2 O 3 , 7 to 26 mol % of NiO, 13 to 36 mol % of ZnO, 7 to 12 mol % of CuO and 0 to 1.5 mol % of CoO, as calculated in terms of the respective oxides, in which the ferrite sintered plate has a volume resistivity of 1×10 8 to 1×10 12 ·cm and a thickness of 10 to 60 μm; and a ferrite sintered sheet comprising the ferrite sintered plate on a surface of which a groove or grooves are formed, and an adhesive layer and/or a protective layer formed on the ferrite sintered plate, in which the ferrite sintered sheet has a magnetic permeability at 500 kHz a real part of which is 120 to 800 and an imaginary part of which is 0 to 30, and a product (μm) of the real part of the magnetic permeability at 500 kHz of the ferrite sintered sheet and a thickness of the ferrite sintered plate is 5000 to 48000. The ferrite sintered plate and the ferrite sintered sheet according to the present invention have a high volume resistivity as well as a large μ′ value and a small μ″ value of a magnetic permeability thereof, and therefore can be suitably used as a shielding plate in a digitizer system.

First claim

The invention claimed is:

1. A ferrite sintered plate which has a composition comprising 47 to 50 mol % of Fe 2 O 3 , 7.0 to 15.1 mol % of NiO, 13 to 36 mol % of ZnO, 7.0 to 12 mol % of CuO and 0 to 1.5 mol % of CoO, as calculated in terms of the respective oxides, which has a volume resistivity of 1×10 8 to 1×10 12 Ω cm and which has a thickness of 10 to 60 μm, wherein the ferrite sintered plate has a magnetic permeability at 500 kHz a real part of which is 296 to 1200 and an imaginary part of which is 0 to 90.

2. The ferrite sintered plate according to claim 1 , wherein a product (μm) of the real part of the magnetic permeability at 500 kHz of the ferrite sintered plate and a thickness of the ferrite sintered plate is 7500 to 72000.

3. The ferrite sintered plate according to claim 1 , wherein at least one groove is formed on at least one surface of the ferrite sintered plate and the depth of the at least one groove is 1/20 to ¼ of a thickness of the ferrite sintered plate.

4. A ferrite sintered sheet comprising the ferrite sintered plate according to claim 1 , and an adhesive layer or a protective layer which is formed on at least one surface of the ferrite sintered plate.

5. A ferrite sintered sheet comprising the ferrite sintered plate according to claim 1 , an adhesive layer formed on one surface of the ferrite sintered plate, and a protective layer formed on the other surface of the ferrite sintered plate.

6. A ferrite sintered sheet comprising the ferrite sintered plate according to claim 1 , and adhesive layers respectively formed on opposite surfaces of the ferrite sintered plate.

7. A ferrite sintered sheet comprising the ferrite sintered plate according to claim 1 , and protective layers respectively formed on opposite surfaces of the ferrite sintered plate.

8. The ferrite sintered sheet according to claim 4 , wherein the ferrite sintered plate is partitioned into small pieces.

9. The ferrite sintered sheet according to claim 8 , wherein the ferrite sintered sheet has a magnetic permeability at 500 kHz a real part of which is 120 to 800 and an imaginary part of which is 0 to 30, and a product of the real part of the magnetic permeability at 500 kHz of the ferrite sintered sheet and a thickness of the ferrite sintered plate is 5000 to 48000.

10. A digitizer system comprising a detector and a shielding plate disposed adjacent to the detector, in which the shielding plate is constituted of the ferrite sintered plate according to claim 1 .

11. A digitizer system comprising a detector and a shielding plate disposed adjacent to the detector, in which the shielding plate is constituted of the ferrite sintered sheet according to claim 4 .

Assignees

• Toda Kogyo Corp

Inventors

• Okano Yoji
• Sadai Makoto
• Honda Shingo
• Kurumada Mitsunori
• Yoshida Akihiro
• Kawato Kazuyoshi

Classifications

• G06F2203/04107

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