Taiyo Yuden Co., Ltd.

Tomomi Kobayashi

Hitoshi Matsuura

Kenji Otake

Kenichiro Nogi

Hidemi Iwao

Yoshikazu Okino

Kenji Yazawa

Norihiro Asako

Makoto Aoki

Takashi Nakajima

Takayuki Arai

Masahiro Hachiya

Yoshiaki Kamiyama

Yukihiro Noro

Yoshie Amamiya

When manufacturing a magnetic body which is made of a ferrite material containing Fe, Ni, and Zn, and whose Mn content is 0.1288 percent by mass or higher, or a magnetic body which is made of a ferrite material containing Fe, Ni, Zn, and Cu, and whose Mn content is 0.1178 percent by mass or higher, an iron oxide powder whose Mn content is 0.20 percent by mass or higher is used as a raw material powder.

Method for manufacturing magnetic body and coil component containing magnetic body

When manufacturing a magnetic body whose primary component is Ni&#x2014;Zn ferrite, an iron oxide powder whose Mn content is 0.20 to 0.85 percent by mass is used as a raw material powder, or, in addition to using an iron oxide powder whose Mn content is 0.20 percent by mass or higher as a raw material powder, a mol ratio of Ni to Zn (Ni/Zn) in the ferrite material is determined based on the Mn content in the iron oxide powder and the raw material powders are compounded in such a way that the mol ratio is achieved. The magnetic body does not contain any additives as essential components other than the primary components of the Ni&#x2014;Zn ferrite material. A coil component using the magnetic body has excellent direct-current superimposition property and magnetic permeability.

A coil component is of the type where a helical coil is directly contacting a magnetic body where such coil component still meets the demand for electrical current amplification. The coil component is structured in such a way that a helical coil is covered with a magnetic body. The magnetic body is mainly constituted by magnetic alloy grains and contains substantially no glass component, and each of the magnetic alloy grains has an oxide film of the grain on its surface.

Coil component

A coil component is of the type where a helical coil is directly contacting a magnetic body where such coil component still meets the demand for electrical current amplification. The coil component is structured in such a way that a helical coil is covered with a magnetic body. The magnetic body is mainly constituted by magnetic alloy grains and does not contain glass component, and each of the magnetic alloy grains has an oxide film of the grain on its surface.

Disclosed is a laminated inductor that has good direct current superimposition characteristics, does not cause a variation in temperature characteristics, suppresses the occurrence of delamination, and can be stably manufactured. Also disclosed are a method for manufacturing the laminated inductor and a laminated choke coil. A laminated inductor () for use as a choke coil in a power supply circuit includes a rectangular parallelepiped-shaped laminated chip () and at least one pair of external electrodes () that are provided at the end of the laminated chip () and are conductively connected to the end of a coil. The laminated chip () includes a plurality of magnetic material layers () formed of an Ni&#x2014;Zn&#x2014;Cu ferrite, a plurality of conductive layers (), which are laminated through the magnetic material layers () to constitute a coil, and at least one nonmagnetic layer () formed of a Ti&#x2014;Ni&#x2014;Cu&#x2014;Mn&#x2014;Zr&#x2014;Ag-base dielectric material and formed in contact with a plurality of the magnetic material layers ().

Laminated inductor, method for manufacturing the laminated inductor, and laminated choke coil

A laminated inductor having a laminate structure constituted by magnetic layers and internal conductive wire-forming layers, wherein the magnetic layer is formed by soft magnetic alloy grains, the internal conductive wire-forming layer has an internal conductive wire and a reverse pattern portion around it, and the reverse pattern portion is formed by soft magnetic alloy grains whose constituent elements are of the same types as those of, and whose average grain size is greater than that of, the soft magnetic alloy grains constituting the magnetic layer.

Laminated inductor

A coil component is of the type where a helical coil is directly contacting a magnetic body, which is still capable of meeting the demand for electrical current amplification. A coil component, comprising a magnetic body mainly constituted by magnetic alloy grains, and a coil formed on the magnetic body; wherein an oxide film of the magnetic alloy grains is present on the surface of each of the magnetic alloy grains, and based on grain size by volume standard, the magnetic alloy grains have a d50 in a range of 3.0 to 20.0 &#x3bc;m, d10/d50 in a range of 0.1 to 0.7, and d90/d50 in a range of 1.4 to 5.0.

Growing community of inventors

Takasaki, Japan

Tomomi Kobayashi