US 11,657,949 B2
Magnetic core and coil component
Kyohei Tonoyama, Tokyo (JP); Ken Satoh, Tokyo (JP); Kentaro Saito, Tokyo (JP); Miyuki Asai, Tokyo (JP); and Hitoshi Ohkubo, Tokyo (JP)
Assigned to TDK CORPORATION, Tokyo (JP)
Filed by TDK CORPORATION, Tokyo (JP)
Filed on Oct. 25, 2019, as Appl. No. 16/663,464.
Claims priority of application No. JP2018-205396 (JP), filed on Oct. 31, 2018.
Prior Publication US 2020/0135380 A1, Apr. 30, 2020
Int. Cl. H01F 27/28 (2006.01); H01F 27/255 (2006.01); H01F 17/00 (2006.01); H01F 17/04 (2006.01); H01F 27/29 (2006.01); H01F 27/32 (2006.01)
CPC H01F 27/255 (2013.01) [H01F 17/0013 (2013.01); H01F 17/04 (2013.01); H01F 27/2804 (2013.01); H01F 27/292 (2013.01); H01F 27/324 (2013.01); H01F 2017/048 (2013.01); H01F 2027/2809 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A magnetic core comprising a metal magnetic powder, in which
the metal magnetic powder includes a large size powder, an intermediate size powder, and a small size powder,
a particle size of the large size powder is 10 μm or more and 60 μm or less,
a particle size of the intermediate size powder is 2.0 μm or more and less than 10 μm,
a particle size of the small size powder is 0.1 μm or more and less than 2.0 μm,
the large size powder includes a nano crystal,
a ratio of the large size powder existing with respect to the metal magnetic powder is 39% or more and 91% or less in terms of an area ratio in a cross section of the magnetic core and
a ratio of the intermediate size powder existing with respect to a ratio of the small size powder is 0.73 or more and 5.7 or less, each ratio being in terms of an area ratio in a cross section of the magnetic core.