Tdk Corporation

Kenji Komorita

Takahiro Sato

Takashi Endo

Hidekazu Sato

Tatsuro Suzuki

Takashi Suzuki

Yukio Takahashi

Yusuke Nagai

Hitoshi Kudo

Hiroko Korikawa

Yasuhiro Ito

Makoto Yoshino

Masazumi Arata

Kunihiko Kawasaki

Takeru Sasaki

Kouichi Kakuda

Hiroyuki Tanoue

Takeshi Shibayama

Yuya Oshima

Yuusuke Nagai

Yoshimitsu Satoh

Masayuki Suzuki

Shigeshi Osawa

Takehiro Ishii

Tsubasa Ozawa

Yuudai Katou

A multilayer coil component includes an element body having a multilayer structure including a first element body portion formed of a ferrite element body material, and a second element body portion laminated on the first element body portion and formed of a ferrite element body material having a composition different from the ferrite element body material forming the first element body portion, a multilayer coil having an axis parallel to a lamination direction of the element body, and a stress alleviation portion provided in an inner region of the multilayer coil when viewed from the lamination direction. In the multilayer coil component, the stress alleviation portion is provided in the inner region of the multilayer coil in which a stress tends to be concentrated to alleviate the stress in the inner region of the multilayer coil, and thereby occurrence of cracking in the element body can be suppressed.

Multilayer coil component

In the multi-layer coil component, the hole portion is provided in the vicinity of the side surface of the element body, and the distance from the tip position of the external electrode to the hole portion is shorter than the distance from the tip position of the external electrode to the coil. Therefore, when a crack is generated starting from the tip position of the external electrode on the mounting surface, the crack progress toward the hole portion located at a distance closer than the coil. Therefore, in the multi-layer coil component, splitting of the coil due to the crack can be prevented.

Multi-layer coil component

A ferrite composition includes a main component and a sub-component. The main component includes 10.0 to 38.0 mol % of a Fe compound in terms of FeO, 3.0 to 11.0 mol % of a Cu compound in terms of CuO, 39.0 to 80.0 mol % (excluding 39.0 mol %) of a Zn compound in terms of ZnO, and a balance of a Ni compound. The sub-component includes 10.0 to 23.0 parts by weight of a Si compound in terms of SiO, 0 to 3.0 parts by weight (including 0 parts by weight) of a Co compound in terms of CoO, and 0.1 to 3.0 parts by weight of a Bi compound in terms of BiOwith respect to 100 parts by weight of the main component.

Ferrite composition and multilayer electronic component

A multilayer coil component includes an element body, a coil including a plurality of internal conductors, and a plurality of stress-relaxation spaces. The plurality of internal conductors are separated from each other in a first direction in the element body. Each stress-relaxation space is in contact with a surface of the corresponding internal conductor and powders exist in each stress-relaxation space. The element body includes element body regions located between the internal conductors adjacent to each other in the first direction. Each stress-relaxation space includes a first boundary surface with each internal conductor and a second boundary surface with each element body region. The first boundary surface and the second boundary surface oppose each other in the first direction. A distance between the first boundary surface and the second boundary surface is smaller than a thickness of each element body region in the first direction.

In a multilayer coil component, even when both pairs of ends of a first coil part and a second coil part are located at the same positions when viewed from the laminated direction and have the same shapes, a connecting part is connected only to a second end of the first coil part on the upper side in the laminated direction, and is connected only to a first end of the second coil part on the lower side in the laminated direction. Thus, a coil wound around along the laminated direction is structured without misaligning the positions of respective connecting parts. Consequently, the entire shapes of the respective coil parts can be designed to be the exact same shape, which makes it possible to reduce the number of types of coil part, saving labor and time for preparing many types of conductor patterns like the conventional type.

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Tokyo, Japan

Kenji Komorita