Ferrite ceramics, ferrite sintered plate and ferrite sintered sheet

Patent metadata

Field	Value
Publication number	US-10128029-B2
Application number	US-201415032711-A
Country	US
Kind code	B2
Filing date	Oct 30, 2014
Priority date	Oct 31, 2013
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

An object or technical task of the present invention is to provide a ferrite sintered sheet having a dense ferrite microfine structure which has a large μ′ value, a small μ″ value, and a small temperature-dependent change of the μ′ value thereof. The present invention relates to a ferrite ceramics having a composition comprising 47.5 to 49.8 mol % of Fe2O3, 13.5 to 19.5 mol % of NiO, 21 to 27 mol % of ZnO, 7.5 to 12.5 mol % of CuO and 0.2 to 0.8 mol % of CoO, all of the molar amounts being calculated in terms of the respective oxides, the ferrite ceramics further comprising 0.2 to 1.4% by weight of SnO2 and 0.005 to 0.03% by weight of S and having a density of 5.05 to 5.30 g/cm3; 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.

First claim

The invention claimed is:

1. A ferrite sintered sheet comprising a ferrite sintered plate, an adhesive layer or a protective layer that is formed on one surface of the ferrite sintered plate, and an adhesive layer or a protective layer that is formed on an opposite surface of the ferrite sintered plate,
wherein the ferrite sintered plate comprises a ferrite ceramics having a composition comprising 47.5 to 49.8 mol % of Fe 2 O 3 , 13.5 to 19.5 mol % of NiO, 21 to 27 mol % of ZnO, 7.5 to 12.5 mol % of CuO and 0.2 to 0.8 mol % of CoO, all of the molar amounts being calculated in terms of the respective oxides, which ferrite ceramics further comprises 0.2 to 1.4% by weight of SnO 2 and 0.005 to 0.03% by weight of S based on a weight of ferrite ceramics having the composition, and
wherein a temperature-dependent change of a μ′ value of the ferrite sintered sheet calculated as a ratio of a difference between a real part μ′ 85 of a magnetic permeability of the ferrite sintered sheet measured at 85° C. and a real part μ′ 25 of a magnetic permeability of the ferrite sintered sheet measured at 25° C. to the real part μ′ 25 ((μ′ 85 −μ′ 25 )/μ′ 25 )) is 5 to 30%.

2. The ferrite sintered sheet according to claim 1 , wherein the ferrite sintered plate has a density of 5.05 to 5.30 g/cm 3 .

3. The ferrite sintered sheet according to claim 1 , wherein at least one groove is formed on at least one surface of the ferrite sintered plate.

4. The ferrite sintered sheet according to claim 1 , wherein the ferrite sintered plate is divided into parts.

5. The ferrite sintered sheet according to claim 1 , wherein a μ′ value of the ferrite sintered sheet measured at 25° C. is 90 to 180.

6. The ferrite sintered sheet according to claim 1 , wherein a μ″ value of the ferrite sintered sheet measured at 25° C. is 0.05 to 5.

Assignees

• Toda Kogyo Corp

Inventors

• Okano Yoji
• Dote Tomohiro
• Sadai Makoto
• Honda Shingo
• Nakai Katsumi
• Fujii Yasuhiko

Classifications

• C04B35/638

  Removal thereof · CPC title

• H01Q1/38

  formed by a conductive layer on an insulating support {(patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface  H01Q15/142)} · CPC title

• C04B35/26 Primary

  based on ferrites · CPC title

• C04B2235/6025

  Tape casting, e.g. with a doctor blade · CPC title

• C04B2235/72

  Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics · CPC title