Ferrite material and electronic component using the same

• US 7,378,036 B2
• Filed: 10/26/2005
• Issued: 05/27/2008
• Est. Priority Date: 11/29/2004
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Asakura, Kensaku, Matsukawa, Atsuhito, Aoki, Takuya, Wada, Ryuichi
• Primary Examiner(s): KOSLOW, CAROL M
• Application Number:
  US11/258,269
• Publication Number:
  US 20060116283A1
• Time in Patent Office: 944 Days
• Field of Search: 252/62.6, 252/62.62, 252/62.59, 336/117, 336/221, 336/233, 336/234, 333/185
• US Class Current: 252/62.6
• CPC Class Codes: C04B 2235/3241 Chromium oxides, chromates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3279 Nickel oxides, nickalates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3281 Copper oxides, cuprates or oxide-forming salts thereof, e.g. CuO or Cu2O
• CPC Class Codes: C04B 2235/3284 Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
• CPC Class Codes: C04B 2235/3293 Tin oxides, stannates or oxide forming salts thereof, e.g. indium tin oxide [ITO]
• CPC Class Codes: C04B 2235/3298 Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/96 Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 35/265 Compositions containing one or more ferrites of the group comprising manganese or zinc and one or more ferrites of the group comprising nickel, copper or cobalt
• CPC Class Codes: C04B 35/62655 Drying, e.g. freeze-drying, spray-drying, microwave or supercritical drying
• CPC Class Codes: H01F 1/344 Ferrites, e.g. having a cubic spinel structure (X2+O)(Y23+O3), e.g. magnetite Fe3O4
• CPC Class Codes: H01F 17/0013 with stacked layers

Abstract

A ferrite material of the present invention is configured such that 0.05 to 1.0 wt % of bismuth oxide in terms of Bi₂O₃, 0.5 to 3.0 wt % of tin oxide in terms of SnO₂, and 30 to 5000 wt ppm of chromium oxide in terms of Cr₂O₃ are added to a predetermined main component mixture composition. Therefore, it is possible to achieve an improvement in DC bias characteristics, an improvement in temperature characteristics of initial magnetic permeability, and an improvement in resistivity and further achieve an improvement in burned body strength, particularly in burned body flexural strength (bending strength).

Claims

1. A NiCuZn-based ferrite material containing, as main components, 43.0 to 49.8 mol % of iron oxide in terms of Fe₂O₃, 5.0 to 14.0 mol % of copper oxide in terms of CuO, 3.0 to 32.0 mol % of zinc oxide in terms of ZnO, and remaining mol % of nickel oxide in terms of NiO,

wherein 0.05 to 1.0 wt % of bismuth oxide in terms of Bi₂O₃, 0.5 to 3.0 wt % of tin oxide in terms of SnO₂, and 30 to 5000 wt ppm of chromium oxide in terms of Cr₂O₃ are added to said main components.

2. A NiCuZn-based ferrite material according to claim 1, wherein 0.1 to 0.7 wt % of bismuth oxide in terms of Bi₂O₃ is added to said main components.

3. A NiCuZn-based ferrite material according to claim 1, wherein 1.0 to 2.5 wt % of tin oxide in terms of SnO₂ is added to said main components.

4. A NiCuZn-based ferrite material according to claim 1, wherein 100 to 3000 wt ppm of chromium oxide in terms of Cr₂O₃ is added to said main components.

5. An electronic component comprising a NiCuZn-based ferrite material,

wherein said NiCuZn-based ferrite material contains, as main components, 43.0 to 49.8 mol % of iron oxide in terms of Fe₂O₃, 5.0 to 14.0 mol % of copper oxide in terms of CuO, 3.0 to 32.0 mol % of zinc oxide in terms of ZnO, and remaining mol % of nickel oxide in terms of NiO, and

wherein 0.05 to 1.0 wt % of bismuth oxide in terms of Bi₂O₃, 0.5 to 3.0 wt % of tin oxide in terms of SnO₂, and 30 to 5000 wt ppm of chromium oxide in terms of Cr₂O₃ are added to said main components.

6. An electronic component according to claim 5, wherein said electronic component is a multilayer inductor or a multilayer LC composite component comprising a coil conductor and a core portion made of said NiCuZn-based ferrite material and forming a closed magnetic circuit.