US 12,009,135 B2
Coil device
Syun Ashizawa, Tokyo (JP); Takahiro Banzai, Tokyo (JP); Riku Umeki, Tokyo (JP); Satoshi Sugimoto, Tokyo (JP); and Hitoshi Sasaki, Tokyo (JP)
Assigned to TDK CORPORATION, Tokyo (JP)
Filed by TDK CORPORATION, Tokyo (JP)
Filed on Feb. 26, 2021, as Appl. No. 17/186,425.
Claims priority of application No. 2020-032469 (JP), filed on Feb. 27, 2020.
Prior Publication US 2021/0272736 A1, Sep. 2, 2021
Int. Cl. H01F 27/24 (2006.01); H01F 3/14 (2006.01); H01F 17/04 (2006.01); H01F 27/26 (2006.01); H01F 27/28 (2006.01); H01F 27/29 (2006.01); H01F 41/04 (2006.01)
CPC H01F 27/24 (2013.01) [H01F 3/14 (2013.01); H01F 17/04 (2013.01); H01F 27/263 (2013.01); H01F 27/2852 (2013.01); H01F 27/29 (2013.01); H01F 41/04 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A coil device comprising:
a main core including a middle leg for winding a coil body and an outer leg connected with the middle leg via a base portion; and
a sub core disposed to face the base portion across the middle leg,
wherein the main core has a relative permeability of 15-100,
a gap between the middle leg and the sub core is wider than that between the outer leg and the sub core,
the sub core is fixed to the main core with an adhesive agent disposed on a top surface of the middle leg,
no adhesive agent exists between the outer leg and the sub core,
the gap between the middle leg and the sub core has a width of 15 to 55 μm, wherein the gap between the middle leg and the sub core is located around the adhesive agent,
the coil body is made of a plate conductor and wound around the middle leg by less than one turn, and
a height from a bottom surface of a recess, formed on the main core for accommodating the coil body, to the top surface of the middle leg is smaller than a height from the bottom surface of the recess to a top surface of the outer leg.