公开(公告)号：US20180322998A1

公开(公告)日：2018-11-08

申请号：US15968036

申请日：2018-05-01

Applicant: TDK CORPORATION

Inventor： Yasuhide YAMASHITA ,  Katsushi YASUHARA ,  Chiomi SATO ,  Syota GOTO

IPC: H01F27/255 ,  B29C43/18 ,  H01F27/02 ,  H01F41/04

CPC classification number: H01F27/255 ,  B29C43/18 ,  H01F1/36 ,  H01F27/02 ,  H01F41/04 ,  H01F2017/046 ,  H01F2017/048

Abstract: An inductor element includes a wire-winding portion and a core portion. In the wire-winding portion, a conductor is wound in a coil shape. The core portion surrounds the wire-winding portion and contains a magnetic powder and a resin. An inner-core central region is a region of the core portion within a distance from a winding axis center of the wire-winding portion toward an existing region of the wire-winding portion in an outward direction perpendicular to the winding axis center. A top-plate central region is a region of the core portion within a distance from the winding axis center toward a no-existing region of the wire-winding portion in the outward direction. Sα−Sβ≥−2% is satisfied, where Sα (%) and sβ (%) are respectively an area ratio of the magnetic powder in the inner-core central region and the top-plate central region.