US 12,073,978 B2
Coil-embedded dust core, inductance element, and electric or electronic device
Ryo Nakabayashi, Niigata-ken (JP); Akinori Kojima, Niigata-ken (JP); Akira Sato, Niigata-ken (JP); Keiichiro Sato, Niigata-ken (JP); and Masahiro Iizuka, Niigata-ken (JP)
Assigned to Alps Alpine Co., Ltd., Tokyo (JP)
Filed by Alps Alpine Co., Ltd., Tokyo (JP)
Filed on Oct. 27, 2020, as Appl. No. 17/081,644.
Application 17/081,644 is a continuation of application No. PCT/JP2019/011818, filed on Mar. 20, 2019.
Claims priority of application No. 2018-114527 (JP), filed on Jun. 15, 2018.
Prior Publication US 2021/0074464 A1, Mar. 11, 2021
Int. Cl. H01F 27/25 (2006.01); H01F 17/04 (2006.01); H01F 27/255 (2006.01); H01F 41/02 (2006.01)
CPC H01F 27/255 (2013.01) [H01F 17/04 (2013.01); H01F 41/0246 (2013.01); H01F 2017/046 (2013.01); H01F 2017/048 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A coil-embedded dust core comprising:
a dust core containing a magnetic powder; and
a coil embedded in the dust core, the coil having a winding axis along a first direction and a winding body wound around the winding axis, the dust core including a first region located on an inner side of the winding body and a second region located on an outer side of the winding body viewed from the first direction,
wherein the coil-embedded dust core has an inner core volume ratio RV defined as:
RV=(V1/V2)/(1−V/Vp), which is equal to or greater than 3 and equal to or smaller than 5,
where V1 represents a volume of the first region of the dust core, V2 represents a volume of the second region of the dust core, V represents a volume of the dust core, and Vp represents a volume of the coil-embedded dust core.