Toda Kogyo Corporation

Nitto-denko Corporation

Tomohiro Dote

Yoji Okano

Tetsuya Kimura

Yoshiro Sato

Kazumi Yamamoto

Yasuhiko Fujii

Katsumi Okayama

Takanori Doi

Kazuhiro Ikemura

Norio Sugita

Yasushi Nishio

Hiromitsu Sakurai

Shigehisa Yamamoto

Masaharu Abe

Makoto Sadai

Shingo Honda

Takuya Eto

Kazumasa Igarashi

Masataka Tada

Kaoru Kobayashi

Katsumi Nakai

Kazushi Nishimoto

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 &#x3bc;' value, a small &#x3bc;&#x2033; value, and a small temperature-dependent change of the &#x3bc;&#x2032; value thereof. The present invention relates to a ferrite ceramics having a composition comprising 47.5 to 49.8 mol % of FeO, 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 SnOand 0.005 to 0.03% by weight of S and having a density of 5.05 to 5.30 g/cm; 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.

Ferrite ceramics, ferrite sintered plate and ferrite sintered sheet

The present invention relates to an Ni&#x2014;Zn&#x2014;Cu&#x2014;Co ferrite sintered plate having a composition comprising 45 to 50 mol % of FeO, 10 to 25 mol % of NiO, 15 to 36 mol % of ZnO, 2 to 14 mol % of CuO and 0.1 to 3.5 mol % of CoO, all of the molar amounts being calculated in terms of the respective oxides, and a ferrite sintered sheet that is provided on a surface thereof with a groove and further with an adhesive layer and/or a protective layer. The ferrite sintered sheet is capable of exhibiting an increased &#x3bc;' value of a magnetic permeability while maintaining a small &#x3bc;&#x2033; value of the magnetic permeability.

Ferrite sintered plate and ferrite sintered sheet

An object of the present invention is to provide a ferrite material that is excellent in temperature characteristic and DC superimposition characteristic. The present invention relates to Ni&#x2014;Zn&#x2014;Cu-based ferrite particles comprising 70 to 95% by weight of an Ni&#x2014;Zn&#x2014;Cu ferrite having a specific composition, 1 to 20% by weight of nickel oxide, 0 to 20% by weight of zinc oxide and 1 to 10% by weight of copper oxide, and a ferrite sintered ceramics obtained by sintering the ferrite particles.

Ni&#x2014;Zn&#x2014;Cu-based ferrite particles, green sheet comprising the Ni&#x2014;Zn&#x2014;Cu-based ferrite particles and Ni&#x2014;Zn&#x2014;Cu-based ferrite sintered ceramics

The present invention relates to a molded ferrite sheet having opposing surfaces and a thickness in a range of 30 &#x3bc;m to 430 &#x3bc;m, at least one surface of said opposing surfaces having the following surface roughness characteristics (a) to (c):

Molded ferrite sheet, sintered ferrite substrate and antenna module

A Ni&#x2014;Zn&#x2014;Cu ferrite material having excellent DC bias characteristics is provided by adding zinc silicate thereto. The above problem can be solved by Ni&#x2014;Zn&#x2014;Cu ferrite particles which comprise a spinel-type ferrite and zinc silicate, which have a composition comprising 36.0 to 48.5 mol % of FeO, 7.0 to 38 mol % of NiO, 4.5 to 40 mol % of ZnO, 5.0 to 17 mol % of CuO and 1.0 to 8.0 mol % of SiO, all amounts being calculated in terms of the respective oxides, and which have a ratio of an X-ray diffraction intensity from a 113 plane of the zinc silicate to an X-ray diffraction intensity from a 311 plane of the spinel-type ferrite is 0.01 to 0.12; a green sheet obtained by forming a material comprising the Ni&#x2014;Zn&#x2014;Cu ferrite particles into a film; and a Ni&#x2014;Zn&#x2014;Cu ferrite sintered ceramics.

Ni&#x2014;Zn&#x2014;Cu ferrite particles, green sheet comprising the Ni&#x2014;Zn&#x2014;Cu ferrite particles and Ni&#x2014;Zn&#x2014;Cu ferrite sintered ceramics

A magnetic antenna, suitable for use in an RFID tag and an RFID tag reader/writer, which operates stable even if brought close to a metallic object and suitable for mass-production, and a board mounted with the magnetic antenna. The magnetic antenna has a coil with a magnetic layer and a conductive layer provided on the magnetic layer via an insulating layer or has a plurality of coils each with a magnetic layer having a square or rectangular shape and arranged radially.

Magnetic antenna and board mounted with the same

There is provided a magnetic antenna, suitable for use in an RFID tag and an RFID tag reader/writer, which operates stable even if brought close to a metallic object and suitable for mass-production, and a board mounted with the magnetic antenna. The magnetic antenna has a coil comprising a magnetic layer and a conductive layer provided on the magnetic layer via an insulating layer. Alternatively, the magnetic antenna has a plurality of coils each comprising a magnetic layer having a square or rectangular shape and arranged radially. One ends of the coils are connected in series or parallel to one another by the magnetic layers thereof such that the coils have the same polarity. An insulating layer is provided on one or both outer surface of the coils, and a conductive layer is provided on an outer surface of at least one of the insulating layers. The magnetic antenna is produced using an LTCC technology.

Growing community of inventors

Otake, Japan

Tomohiro Dote