Magnetic sensor device and method for producing same

Abstract

A magnetic sensor device includes: a magnetic circuit for forming a magnetic field, a magnetoresistance effect element, and a heat dissipator. The magnetoresistance effect element outputs changes in the magnetic field as changes in a resistance value, and is arranged on a surface (of a +Z side) of the magnetic circuit at a conveyance path side thereof. The heat dissipator is arranged in close contact with the magnetic circuit at the opposite side thereof (−Z side) from the conveyance path.

1 : A magnetic sensor device comprising:
 a magnetic circuit forming a magnetic field;   a magnetoresistance effect element, mounted on a surface of a conveyance path side of an object to be detected of the magnetic circuit, and configured to output a change of the magnetic field as a change of a resistance value; and   a heat dissipator disposed in close contact with a surface of the magnetic circuit other than the surface of the conveyance path side of the magnetic circuit; wherein   the magnetic circuit comprises:   a magnet, a metallic carrier, having one surface in close contact with the surface of the conveyance path side of the magnet, and carrying the magnetoresistance effect element on another surface, and a yoke having one surface closely contacting a surface of the magnet of a side opposite to the conveyance path side, and having another surface closely contacting the heat dissipator, and   the heat dissipator is disposed in close contact with the surface of the magnetic circuit of a side opposite to the conveyance path side of the magnetic circuit, and comprises a pair of sidewalls, extending in a direction parallel to the surface of the conveyance path side of the heat dissipator, and extending in a direction perpendicular to a conveyance direction of the object to be detected, and the yoke and the magnet are disposed between the pair of sidewalls.   
     
     
         2 - 3 . (canceled) 
     
     
         4 : A magnetic sensor device comprising:
 a magnetic circuit forming a magnetic field;   a magnetoresistance effect element, mounted on a surface of a conveyance path side of an object to be detected of the magnetic circuit, and configured to output a change of the magnetic field as a change of a resistance value; and   a heat dissipator disposed in close contact with a surface of the magnetic circuit other than the surface of the conveyance path side of the magnetic circuit; wherein   the heat dissipator is disposed in close contact with the surface of the magnetic circuit of a side opposite to the conveyance path side of the magnetic circuit,   the magnetic circuit comprises, a magnet, a metallic carrier, having one surface in close contact with the surface of the conveyance path side of the magnet, and carrying the magnetoresistance effect element on another surface, and a yoke having one surface closely contacting a surface of the magnet opposite to the conveyance path side, and having another surface closely contacting the heat dissipator,   the metallic carrier comprises:   a magnetic body upon which is disposed the magnetoresistance effect element; and   a non-magnetic body bonded to the magnetic body and to carry a signal processor electrically connected to the magnetoresistance effect element.   
     
     
         5 - 6 . (canceled) 
     
     
         7 : The magnetic sensor device according to  claim 4 , wherein
 the heat dissipator comprises:   a base that is plate-like; and   a pair of fins extending from both conveyance-direction ends of the base.   
     
     
         8 : The magnetic sensor device according to  claim 1 , wherein the magnetic sensor device further comprises a housing in which a hole is formed that penetrates in a direction orthogonal to the surface of the conveyance path side of the housing and orthogonal to the conveyance direction; and
 the hole contains the magnetic circuit, the magnetoresistance effect element, and the heat dissipator.   
     
     
         9 : The magnetic sensor device according to  claim 8 , wherein
 in a surface of the housing opposite to the conveyance path side are formed:   a board mounting surface for mounting of a board; and   an offset surface offset from the board mounting surface toward the conveyance path side.   
     
     
         10 : The magnetic sensor device according to  claim 8 , wherein
 the heat dissipator contacts an inner circumferential surface of the hole.   
     
     
         11 : The magnetic sensor device according to  claim 8 , wherein
 the heat dissipator is insert-molded in the housing.   
     
     
         12 - 16 . (canceled) 
     
     
         17 : The magnetic sensor device according to  claim 4 , wherein the magnetic sensor device further comprises a housing in which a hole is formed that penetrates in a direction orthogonal to the surface of the conveyance path side of the housing and orthogonal to a conveyance direction; and
 the hole contains the magnetic circuit, the magnetoresistance effect element, and the heat dissipator.   
     
     
         18 : The magnetic sensor device according to  claim 17 , wherein
 in a surface of the housing opposite to the conveyance path side are formed:   a board mounting surface for mounting of a board; and   an offset surface offset from the board mounting surface toward the conveyance path side.   
     
     
         19 : The magnetic sensor device according to  claim 17 , wherein
 the heat dissipator contacts an inner circumferential surface of the hole.   
     
     
         20 : The magnetic sensor device according to  claim 17 , wherein
 the heat dissipator is insert-molded in the housing.   
     
     
         21 : A magnetic sensor device comprising:
 a magnetic circuit forming a magnetic field;   a magnetoresistance effect element, mounted on a surface of a conveyance path side of an object to be detected of the magnetic circuit, and configured to output a change of the magnetic field as a change of a resistance value;   a heat dissipator disposed in close contact with a surface of the magnetic circuit other than the surface of the conveyance path side of the magnetic circuit; and   a housing in which a hole is formed that penetrates in a direction orthogonal to the surface of the conveyance path side of the housing and orthogonal to a conveyance direction,   the hole contains the magnetic circuit, the magnetoresistance effect element, and the heat dissipator, and   the heat dissipator is insert-molded in the housing.   
     
     
         22 : A magnetic sensor device comprising:
 a magnetic circuit forming a magnetic field;   a magnetoresistance effect element, mounted on a surface of a conveyance path side of an object to be detected of the magnetic circuit, and configured to output a change of the magnetic field as a change of a resistance value;   a heat dissipator disposed in close contact with a surface of the magnetic circuit other than the surface of the conveyance path side of the magnetic circuit; and   a housing in which a hole is formed that penetrates in a direction orthogonal to the surface of the conveyance path side of the housing and orthogonal to a conveyance direction, wherein   the hole contains the magnetic circuit, the magnetoresistance effect element, and the heat dissipator, and   in a surface of the housing opposite to the conveyance path side are formed:   a board mounting surface for mounting of a board; and   an offset surface offset from the board mounting surface toward the conveyance path side.