US 12,224,092 B2
Compression molded core, method for manufacturing the compression molded core, inductor including the compression molded core, and electric/electronic equipment mounted with the inductor
Akinori Kojima, Niigata-ken (JP); Ryo Nakabayashi, Niigata-ken (JP); and Keiichiro Sato, Niigata-ken (JP)
Assigned to Alps Alpine Co., Ltd., Tokyo (JP)
Filed by Alps Alpine Co., Ltd., Tokyo (JP)
Filed on Apr. 9, 2021, as Appl. No. 17/227,019.
Application 17/227,019 is a continuation of application No. PCT/JP2019/040011, filed on Oct. 10, 2019.
Claims priority of application No. 2018-203685 (JP), filed on Oct. 30, 2018.
Prior Publication US 2021/0233690 A1, Jul. 29, 2021
Int. Cl. H01F 1/08 (2006.01); H01F 1/147 (2006.01); H01F 1/153 (2006.01); H01F 1/22 (2006.01); H01F 1/26 (2006.01); H01F 27/255 (2006.01); H01F 41/02 (2006.01)
CPC H01F 1/08 (2013.01) [H01F 1/14741 (2013.01); H01F 1/14766 (2013.01); H01F 1/153 (2013.01); H01F 1/22 (2013.01); H01F 1/26 (2013.01); H01F 27/255 (2013.01); H01F 41/0246 (2013.01); H01F 1/15308 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A compression molded core comprising a plurality of types of powders each formed of a soft magnetic material,
wherein a median diameter of each powder is defined as a particle diameter at which an integrated particle diameter distribution becomes 50% when accumulated from a small particle size side based on a volume-based particle size distribution measured by a laser diffraction/scattering method,
wherein the plurality of types of powders include:
a first powder made of an amorphous magnetic material and having a first median diameter D1 which is a greatest median diameter among the median diameters of the plurality of types of powders; and
a second powder made of a crystalline magnetic material and having a second median diameter D2 which is a smallest median diameter among the median diameters of the plurality of types of powders, the second median diameter D2 being smaller than the first median diameter D1,
wherein the first powder has a first weight ratio R1 which is a ratio of a weight of the first powder to a total weight of the first powder and the second powder in the compression molded core, while the second powder has a second weight ratio R2 which is a ratio of a weight of the second powder to the total weight of the first powder and the second powder in the compression molded core, an average median diameter DT being defined as DT=R1×D1+R2×D2,
and wherein the second weight ratio R2, the first median diameter D1, the second median diameter D2, and the average median diameter DT satisfy following expressions (1) to (4):
0.4≤R2≤0.7  (1)
0.23≤(D1−D2)/D1<0.3  (2)
D1≤5.9 μm  (3)
3 μm≤DT≤5.7 μm  (4).