US 11,955,262 B2
Inductor and EMI filter including the same
Mi Jin Lee, Seoul (KR); Ji Yeon Song, Seoul (KR); Yu Seon Kim, Seoul (KR); Jong Wook Lim, Seoul (KR); Seok Bae, Seoul (KR); and Sang Won Lee, Seoul (KR)
Assigned to LG INNOTEK CO., LTD., Seoul (KR)
Filed by LG INNOTEK CO., LTD., Seoul (KR)
Filed on Feb. 16, 2022, as Appl. No. 17/673,245.
Application 17/673,245 is a continuation of application No. 16/473,863, granted, now 11,289,252, previously published as PCT/KR2018/000041, filed on Jan. 2, 2018.
Claims priority of application No. 10-2017-0000745 (KR), filed on Jan. 3, 2017; and application No. 10-2017-0113223 (KR), filed on Sep. 5, 2017.
Prior Publication US 2022/0199305 A1, Jun. 23, 2022
Int. Cl. H01F 1/34 (2006.01); H01F 3/04 (2006.01); H01F 3/08 (2006.01); H01F 17/00 (2006.01); H01F 17/06 (2006.01); H01F 27/245 (2006.01); H01F 41/02 (2006.01)
CPC H01F 1/34 (2013.01) [H01F 3/04 (2013.01); H01F 3/08 (2013.01); H01F 17/0013 (2013.01); H01F 17/06 (2013.01); H01F 27/245 (2013.01); H01F 41/0213 (2013.01); H01F 2017/065 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A power board, comprising:
a board;
a circuit portion formed on the board; and
an EMI filter configured to be electrically connected to the circuit portion,
wherein the EMI filter comprises:
an inductor comprising:
a magnetic core; and
a coil disposed on a surface of the magnetic core, and
a capacitor,
wherein the magnetic core comprises:
a first magnetic body having a toroidal shape, the first magnetic body comprising ferrite;
a second magnetic body disposed on an inner side of the first magnetic body; and
a third magnetic body disposed on an outer side of the first magnetic body,
wherein the second magnetic body is formed in multiple layers in a diameter direction of the first magnetic body on an inner circumferential surface of the first magnetic body,
wherein the third magnetic body is formed in multiple layers in the diameter direction on an outer circumferential surface of the first magnetic body,
wherein a thickness of the first magnetic body is greater than a thickness of the second magnetic body in the diameter direction,
wherein a thickness of the third magnetic body is less than the thickness of the first magnetic body in the diameter direction, and
wherein, when a frequency of a current applied to the inductor is equal to or less than a critical frequency, a relative permeability of each of the second and third magnetic bodies is higher than a relative permeability of the first magnetic body.