JP2019070546A - Magnetic sensor and method of manufacturing the same - Google Patents

Abstract

To make a magnetic sensor which is inexpensive and suppresses a decrease in sensitivity of the magnetic sensor by reducing a use amount of indium antimonite (InSb).SOLUTION: The magnetic sensor includes: a first magnetosensitive element 110 and a second magnetosensitive element 120 including a magnetosensitive body made of a semiconductor film 11 formed on one main surface 10s of a base material 10; a magnetic member 130 positioned between the first and second magneto-sensitive elements 110, 120; and a bias magnet 140 for applying a bias magnetic field to the first and second magneto-sensitive elements 110, 120.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetic sensor and a method of manufacturing the same.

  As a prior art document which disclosed the magnetic sensor provided with the magnetoresistive element, there exists Unexamined-Japanese-Patent No. 8-105950 (patent document 1). In the magnetic sensor described in Patent Document 1, a semiconductor film made of indium antimonite (InSb) formed on a substrate is patterned to form two magnetoresistive elements spaced apart from each other. Indium antimonite (InSb) functions as a magnetosensitive body.

JP-A-8-105950

  In the case of forming a magnetoresistive element by patterning a semiconductor film made of indium antimonite (InSb), the proportion of indium antimonite functioning as a magnetosensitive body in the amount of use of indium antimonite is low. Since indium antimonite (InSb) is an expensive material, it is required to reduce the amount of indium antimonite (InSb) used to make the magnetic sensor inexpensive and to suppress the decrease in the sensitivity of the magnetic sensor.

  The present invention has been made in view of the above problems, and it is possible to reduce the amount of use of indium antimonite (InSb) to make the magnetic sensor inexpensive and to suppress the decrease in the sensitivity of the magnetic sensor and the magnetic sensor The purpose is to provide a manufacturing method.

  The method of manufacturing a magnetic sensor according to the present invention divides a substrate on which a semiconductor film which can be a magnetosensitive body is formed on one main surface, and forms a first magnetosensitive element and a second magnetosensitive element including the magnetosensitive body. Placing the first magneto-sensitive element, the second magneto-sensitive element, and the magnetic member such that the magnetic member is positioned between the first magneto-sensitive element and the second magneto-sensitive element; Arranging a bias magnet for applying a bias magnetic field to the first and second magnetic sensing elements.

  In one mode of a method of manufacturing a magnetic sensor based on the present invention, the substrate and the magnetic member are made of the same magnetic material.

  In one embodiment of the method of manufacturing a magnetic sensor according to the present invention, the semiconductor film is made of indium antimonite (InSb).

  A magnetic sensor according to the present invention comprises a first magnetosensitive element and a second magnetosensitive element including a magnetosensitive body formed of a semiconductor film formed on one of the main surfaces of a substrate, and a first magnetosensitive element and a second magnetosensitive element. And a bias magnet for applying a bias magnetic field to the first magnetic sensing element and the second magnetic sensing element.

  In one form of the magnetic sensor based on the present invention, the substrate and the magnetic member are made of the same magnetic material.

  In one form of the magnetic sensor according to the present invention, the semiconductor film is made of indium antimonite (InSb).

  ADVANTAGE OF THE INVENTION According to this invention, the fall of the sensitivity of a magnetic sensor can be suppressed, reducing the usage-amount of indium antimonite (InSb) and making a magnetic sensor inexpensive.

It is a sectional view showing the composition of the magnetic sensor concerning one embodiment of the present invention. It is the top view which looked at the 1st magnetic sensing element, the 2nd magnetic sensing element, and the magnetic body member with which the magnetic sensor concerning one embodiment of the present invention is seen from the arrow II direction. It is sectional drawing which looked at the 1st magneto-sensitive element of FIG. 2 from the III-III line arrow direction. It is a side view which shows the state which affixed the other main surface of the grind | polished indium antimonide board | substrate on one main surface of a board | substrate. It is a side view which shows the state which has arrange | positioned the 1st magnetic sensing element, the 2nd magnetic sensing element, and the magnetic body member. It is a circuit diagram showing the circuit composition of the magnetic sensor concerning one embodiment of the present invention. It is a graph which shows the relationship between the magnetic field intensity of a bias magnetic field, and the output of the magnetic sensor with respect to a ferromagnetic material and a nonmagnetic material. It is a graph which shows magnetic field intensity distribution of the bias magnetic field in the direction of the X-axis. It is a graph which shows the sensitivity of the magnetic sensor of a comparative example, and the sensitivity of the magnetic sensor concerning this embodiment.

  Hereinafter, a magnetic sensor according to an embodiment of the present invention and a method of manufacturing the same will be described with reference to the drawings. In the following description of the embodiments, the same or corresponding portions in the drawings are denoted by the same reference characters, and the description thereof will not be repeated.

  FIG. 1 is a cross-sectional view showing the configuration of a magnetic sensor according to an embodiment of the present invention. FIG. 2 is a plan view of the first magnetosensitive element, the second magnetosensitive element, and the magnetic member included in the magnetic sensor according to the embodiment of the present invention as viewed in the direction of arrow II. FIG. 3 is a cross-sectional view of the first magnetosensitive element of FIG. 2 as viewed in the direction of arrows of III-III line.

  As shown in FIGS. 1 to 3, a magnetic sensor 100 according to an embodiment of the present invention includes a first magnetic sensing element 110 and a second magnetic sensing element 120, a magnetic member 130, and a bias magnet 140. .

  Each of the first magnetic sensing element 110 and the second magnetic sensing element 120 includes a magnetic sensing body made of a semiconductor film 11 formed on one main surface 10 s of the base material 10. The first magnetic sensing element 110 and the second magnetic sensing element 120 are disposed spaced apart from each other in the X-axis direction. The magnetic member 130 is located between the first magneto-sensitive element 110 and the second magneto-sensitive element 120. The bias magnet 140 applies a bias magnetic field to the first magneto-sensitive element 110 and the second magneto-sensitive element 120.

  In the present embodiment, the first magnetic sensing element 110, the second magnetic sensing element 120, the magnetic member 130 and the bias magnet 140 are accommodated in a case 170 made of resin. A metal cover 180 is attached to the resin case 170. The first magnetic sensing element 110, the second magnetic sensing element 120, and the magnetic member 130 are disposed in a space surrounded by the case 170 and the cover 180.

  The magnetic sensor 100 includes a first terminal 161 electrically connected to the first magnetic sensor 110, a second terminal 162 electrically connected to the second magnetic sensor 120, and the first magnetic sensor 110. It further includes a first connection member 151 connecting the first terminal 161 to each other, and a second connection member 152 connecting the second magnetic sensing element 120 and the second terminal 162 to each other.

  Each of the first connection member 151 and the second connection member 152 is, for example, a wire for wire bonding. Each of the first terminal 161 and the second terminal 162 is drawn from the case 170 to the other side in the Z-axis direction.

  The bias magnet 140 is opposed to the first magnetic sensing element 110 and the second magnetic sensing element 120. The magnetic flux generated by the bias magnet 140 mainly passes through the first magneto-sensitive element 110 and the second magneto-sensitive element 120 in the Z-axis direction.

  As a material of the bias magnet 140, isotropic ferrite, anisotropic ferrite, samarium cobalt, alnico or neodymium can be used. When anisotropic ferrite, samarium cobalt or neodymium is used as the material of the bias magnet 140, the coercivity of the bias magnet 140 can be increased, so that the stability of the magnetic characteristics of the bias magnet 140 can be enhanced. The bias magnet 140 may be composed of a sintered magnet or a bonded magnet.

  Hereinafter, the first magnetosensitive element 110, the second magnetosensitive element 120, and the magnetic member 130 will be described in detail.

  Each of the first and second magneto-sensitive elements 110 and 120 is provided along the Y-axis direction. The base 10 is made of a magnetic material such as ferrite.

  The first magnetic sensing element 110 is disposed between the plurality of unit magnetic sensing bodies 111 and the plurality of unit magnetic sensing bodies 111 one by one between the unit magnetic sensing bodies 111 adjacent to each other, and the plurality of unit magnetic sensing bodies 111 are connected in series. It includes a plurality of connection conductors 112 to be connected. A connection terminal 113 is provided at one end of the first magnetosensitive element 110 in the Y-axis direction. A connection terminal 114 is provided at the other end of the first magnetic sensing element 110 in the Y-axis direction.

  The second magnetic sensing element 120 includes a plurality of unit magnetic sensing elements 121 and a plurality of unit magnetic sensing elements 121 disposed one by one between the unit magnetic sensing elements 121 adjacent to each other in the plurality of unit magnetic sensing elements 121. It includes a plurality of connection conductors 122 to be connected. A connection terminal 123 is provided at one end of the second magnetic sensing element 120 in the Y-axis direction. A connection terminal 124 is provided at the other end of the second magnetic sensing element 120 in the Y-axis direction.

  As shown in FIG. 3, the semiconductor film 11 is formed on the base material 10, and the conductor layer 12 is provided by patterning on the semiconductor film 11. Since the electric resistance of the semiconductor film 11 is higher than the electric resistance of the conductor layer 12, current mainly flows through the conductor layer 12 in the portion where the conductor layer 12 is provided on the semiconductor film 11.

  Portions of the semiconductor film 11 which are not covered by the conductor layer 12 become unit magnetic sensitive bodies 111 and 121, and portions of the semiconductor film 11 which are covered by the conductor layer 12 are connection conductors 112 and 122 or connection terminals 113 and 114, It becomes 123, 124. The conductor layer 12 is made of a metal having a high electrical conductivity such as aluminum. The conductor layer 12 is formed using a vapor deposition apparatus or the like.

  The semiconductor film 11 is made of indium antimonide (InSb). The semiconductor film 11 is composed of a part of an indium antimonide substrate 11m described later. Specifically, the semiconductor film 11 is formed by polishing and thinning the other main surface of the indium antimonide substrate 11 m having a conductor layer 12 m described later formed on one of the main surfaces by vapor deposition. There is.

Here, a method of manufacturing a magnetic sensor according to an embodiment of the present invention will be described.
FIG. 4 is a side view showing a state in which the other main surface of the polished indium antimonide substrate is attached to one main surface of the substrate. As shown in FIG. 4, the other main surface of the polished indium antimonide substrate 11m is attached to one main surface 10ms of the substrate 10m. A conductor layer 12m is formed on one main surface of the indium antimonide substrate 11m.

  In the present embodiment, the first substrate 10m is divided by using a dicer or the like along a cut line C shown in FIG. The magnetosensitive element 110 and the second magnetosensitive element 120 are formed.

  That is, in a state where the other main surface of the polished indium antimonide substrate 11m is attached to one main surface 10ms of the substrate 10m, the substrate 10m and the indium antimonide substrate 11m along the cut line C. By dividing the conductor layer 12m, the first magnetosensitive element 110 and the second magnetosensitive element 120 including the base 10, the semiconductor film 11, and the conductor layer 12 are formed.

  Next, the first magnetosensitive device 110, the second magnetosensitive device 120, and the magnetic member 130 are disposed such that the magnetic member 130 is positioned between the first magnetosensitive device 110 and the second magnetosensitive device 120. Do.

  FIG. 5 is a side view showing a state in which the first magnetosensitive element, the second magnetosensitive element, and the magnetic member are disposed. As shown in FIG. 5, the magnetic member 130 is disposed so as to be sandwiched between the base material 10 of the first magnetic sensing element 110 and the base material 10 of the second magnetic sensing element 120. The magnetic member 130 is made of a magnetic material such as ferrite, which is the same as the base material.

  In the present embodiment, the magnetic member 130 is integrally bonded to each of the base 10 of the first magnetic sensing element 110 and the base 10 of the second magnetic sensing element 120 by an adhesive. In addition, the 1st magnetic sensing element 110, the 2nd magnetic sensing element 120, and the magnetic body member 130 do not necessarily need to be comprised integrally.

  Next, as shown in FIG. 1, the first magnetosensitive device 110, the second magnetosensitive device 120, and the bias magnet 140 are arranged such that a bias magnetic field is applied to the first magnetosensitive device 110 and the second magnetosensitive device 120. Place.

  The connection terminal 113 of the first magnetic sensing element 110 is connected to the first terminal 161 by the first connection member 151. The connection terminal 123 of the second magnetic sensing element 120 is connected to the second terminal 162 by the second connection member 152. The connection terminal 114 of the first magnetic sensing element 110 is connected to the connection terminal 124 of the second magnetic sensing element 120.

  FIG. 6 is a circuit diagram showing a circuit configuration of a magnetic sensor according to an embodiment of the present invention. As shown in FIG. 6, in the magnetic sensor 100 according to an embodiment of the present invention, a half bridge circuit is configured. Specifically, the drive voltage is input to the connection terminal 113. An intermediate potential is output from a connection portion between the connection terminal 114 and the connection terminal 124. The connection terminal 123 is grounded.

  In the magnetic sensor 100 configured as described above, as shown in FIG. 1, with respect to the first magnetic sensing element 110 and the second magnetic sensing element 120, one side in the Z-axis direction with the cover 180 interposed therebetween. The detected object 1 passes through the position in the X-axis direction.

  When the magnetic sensor 100 detects the to-be-detected object 1, there are cases where a ferromagnetic material provided to the to-be-detected object 1 is detected and cases where a nonmagnetic material provided to the to-be-detected object 1 is detected. . Examples of the ferromagnetic material include iron oxide or ferrite. Examples of nonmagnetic materials include austenitic stainless steel.

  It is preferable that the output characteristics of the magnetic sensor 100 be high in both ferromagnetic and nonmagnetic materials. Here, experimental results of simulation analysis of the relationship between the magnetic field strength of the bias magnetic field and the output of the magnetic sensor with respect to the ferromagnetic body and the nonmagnetic body will be described.

  FIG. 7 is a graph showing the relationship between the magnetic field strength of the bias magnetic field and the output of the magnetic sensor for ferromagnetic and nonmagnetic materials. In FIG. 7, the vertical axis represents the output of the magnetic sensor, and the horizontal axis represents the magnetic field strength of the bias magnetic field. In FIG. 7, the output of the magnetic sensor with respect to the ferromagnetic material is indicated by a solid line, and the output of the magnetic sensor with respect to the nonmagnetic material is indicated by a dotted line.

  As shown in FIG. 7, the output of the magnetic sensor with respect to the nonmagnetic material increases as the magnetic field strength of the bias magnetic field increases. On the other hand, the output of the magnetic sensor for the ferromagnetic body increases as the magnetic field strength of the bias magnetic field increases until the magnetic field strength of the bias magnetic field exceeds L1, and after the magnetic field strength of the bias magnetic field exceeds L1, It became small as the magnetic field intensity of the bias magnetic field became large. After the magnetic field strength of the bias magnetic field exceeded L2, the output of the magnetic sensor for the ferromagnetic body was lower than the output of the magnetic sensor for the nonmagnetic body.

  This is because the ferromagnetic material is magnetically saturated when the magnetic field strength of the bias magnetic field becomes L1, and the sensitivity of the magnetic sensor is lowered as the magnetic field strength of the bias magnetic field is increased. Therefore, in order to suppress the decrease in the output of the magnetic sensor with respect to the ferromagnetic body, the magnetic field strength of the bias magnetic field applied to the first and second magnetic sensing elements 110 and 120 should not be too high. is necessary.

  Therefore, in the magnetic sensor 100 according to the present embodiment, the magnetic member 130 is disposed between the first magnetic sensing element 110 and the second magnetic sensing element 120. Here, in the magnetic sensor according to the comparative example in which the magnetic member 130 is not disposed, and the magnetic sensor 100 according to the present embodiment, the experimental result of the simulation analysis of the magnetic field strength distribution in the X axis direction of the bias magnetic field explain.

  FIG. 8 is a graph showing the magnetic field strength distribution of the bias magnetic field in the X-axis direction. In FIG. 8, the vertical axis indicates the magnetic field strength of the bias magnetic field, and the horizontal axis indicates the position in the X-axis direction. In FIG. 8, the output of the magnetic sensor 100 according to the present embodiment is indicated by a solid line, and the output of the magnetic sensor according to the comparative example is indicated by a dotted line. The position L3 in the X-axis direction in FIG. 8 is the position of the first magnetic sensing element 110, and the position L4 in the X-axis direction in FIG. 8 is the position of the second magnetic sensing element 120.

  As shown in FIG. 8, in the magnetic sensor according to the comparative example, since the magnetic member 130 is not disposed at the position between the first magnetic sensing element 110 and the second magnetic sensing element 120 in the X-axis direction, The magnetic field strength of the bias magnetic field increases in the vicinity of the first magnetic sensing element 110 and then decreases rapidly toward the second magnetic sensing element 120 and increases in the vicinity of the second magnetic sensing element 120 again. The

  On the other hand, in the magnetic sensor 100 according to the present embodiment in which the magnetic member 130 is disposed at a position between the first magneto-sensitive element 110 and the second magneto-sensitive element 120 in the X-axis direction, the first magneto-sensitive element The magnetic field strength of the bias magnetic field is maintained substantially constant at a position between the second magnetic sensor element 110 and the second magnetic sensor element 120, and compared to the magnetic sensor according to the comparative example, The magnetic field strength of the bias magnetic field applied to each of the magnetic elements 120 is low.

  FIG. 9 is a graph showing the sensitivity of the magnetic sensor of the comparative example and the sensitivity of the magnetic sensor according to the present embodiment. In FIG. 9, the vertical axis indicates the sensitivity of the magnetic sensor normalized with the sensitivity of the magnetic sensor according to the comparative example set to 1.0, and the horizontal axis indicates the sample name.

  As shown in FIG. 9, the sensitivity of the magnetic sensor 100 according to the present embodiment is about 1.5 times higher than the sensitivity of the magnetic sensor of the comparative example.

  As confirmed from the above experimental results, in the magnetic sensor 100 according to the present embodiment, the magnetic member 130 is located at a position between the first magnetosensitive element 110 and the second magnetosensitive element 120 in the X-axis direction. Because of the arrangement, the magnetic field strengths of the bias magnetic fields applied to the first and second magnetic sensing elements 110 and 120 can be prevented from becoming too high.

  As a result, while increasing the magnetic field strength of the bias magnetic field to increase the output of the magnetic sensor to the nonmagnetic material, the decrease in the sensitivity of the magnetic sensor is suppressed, and the output of the magnetic sensor to the ferromagnetic material is maintained high. it can. Thus, the output of the magnetic sensor 100 for both ferromagnetic and nonmagnetic materials can be increased.

  In the method of manufacturing the magnetic sensor 100 according to the present embodiment, since the semiconductor film made of indium antimonite (InSb) is divided and used without being patterned, it functions as a magnetosensitive body in the amount of use of indium antimonite. The proportion of indium antimonite can be increased. As a result, the amount of indium antimonite (InSb) used can be reduced to make the magnetic sensor 100 inexpensive.

  Further, in the method of manufacturing the magnetic sensor 100 according to the present embodiment, since the substrate 10m and the magnetic member 130 are made of the same magnetic material, the first magnetosensitive element 110 and the second magnetosensitive element are used. The magnetic field strength of the bias magnetic field can be maintained substantially constant at a position between 120 and 120. Thereby, the sensitivity of the magnetic sensor 100 can be stabilized.

  The magnetic sensor 100 according to an embodiment of the present invention may be configured as a multi-channel magnetic sensor. Moreover, the magnetic sensor 100 is applicable to a bill validator or an automatic ticket gate or the like.

  In the description of the above-described embodiments, the combinations of combinations may be combined with each other.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

  DESCRIPTION OF SYMBOLS 1 to-be-detected object, 10 base materials, 10 m board | substrates, 10 ms, 10 s principal surface, 11 semiconductor film, 11 m indium antimonide board | substrate, 12, 12 m conductor layer, 100 magnetic sensor, 110 1st magnetosensitive element, 111, 121 Unit magneto-sensitive member 112, 122 connecting conductor 113, 114, 123, 124 connecting terminal 120 second magneto-sensitive element 130 magnetic member 140 bias magnet 151 first connecting member 152 second connecting member 161 One terminal, 162 second terminal, 170 cases, 180 covers.

Claims (6)

Dividing a substrate on which a semiconductor film capable of becoming a magnetosensitive body is formed on one main surface, and forming a first magnetosensitive element and a second magnetosensitive element including the magnetosensitive body;
Arranging the first magnetosensitive element, the second magnetosensitive element, and the magnetic member such that a magnetic member is positioned between the first magnetosensitive element and the second magnetosensitive element;
And b. Disposing a bias magnet for applying a bias magnetic field to the first and second magnetic sensing elements.   The method for manufacturing a magnetic sensor according to claim 1, wherein the substrate and the magnetic member are made of the same magnetic material.   The method for manufacturing a magnetic sensor according to claim 1, wherein the semiconductor film is made of indium antimonite. A first magnetosensitive element and a second magnetosensitive element including a magnetosensitive body made of a semiconductor film formed on one main surface of the substrate;
A magnetic member positioned between the first and second magnetic sensing elements;
A magnetic sensor comprising: a bias magnet that applies a bias magnetic field to the first and second magnetic sensing elements.   The magnetic sensor according to claim 4, wherein the base and the magnetic member are made of the same magnetic material.   The magnetic sensor according to claim 4, wherein the semiconductor film is made of indium antimonite.

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