WO2018198627A1 - 磁界センサ - Google Patents

磁界センサ Download PDF

Info

Publication number
WO2018198627A1
WO2018198627A1 PCT/JP2018/011971 JP2018011971W WO2018198627A1 WO 2018198627 A1 WO2018198627 A1 WO 2018198627A1 JP 2018011971 W JP2018011971 W JP 2018011971W WO 2018198627 A1 WO2018198627 A1 WO 2018198627A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetic
sensor
sensor chip
unit
magnetic body
Prior art date
Application number
PCT/JP2018/011971
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
圭 田邊
Original Assignee
Tdk株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tdk株式会社 filed Critical Tdk株式会社
Priority to CN201880027973.0A priority Critical patent/CN110546524A/zh
Publication of WO2018198627A1 publication Critical patent/WO2018198627A1/ja

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
    • G01R33/09—Magnetoresistive devices
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N50/00—Galvanomagnetic devices
    • H10N50/10—Magnetoresistive devices

Definitions

  • the present invention relates to a magnetic field sensor, and more particularly to a long magnetic sensor suitable for reading a magnetic pattern embedded in a bill.
  • Patent Document 1 discloses a long magnetic sensor in which a large number of sensor chips having magnetic detection elements are arranged in one direction.
  • an object of the present invention is to provide a magnetic sensor capable of detecting magnetism in a wide range while using a smaller sensor chip.
  • a magnetic sensor includes a plurality of unit magnetic sensors arranged in a predetermined direction, and each of the plurality of unit magnetic sensors includes a sensor chip having an element forming surface on which a magnetic detection element is formed, and the element And a magnetic body that collects magnetic flux on the magnetic detection element, and a length of the magnetic body in the predetermined direction is longer than a length of the sensor chip in the predetermined direction.
  • the size of the sensor chip can be reduced. For this reason, more sensor chips can be manufactured from one collective substrate, and component costs can be greatly reduced.
  • the magnetic detection element preferably includes first and second magnetic detection elements, and the magnetic material is preferably disposed between the first magnetic detection element and the second magnetic detection element. According to this, it is possible to evenly distribute the magnetic flux collected by the magnetic body to the first magnetic detection element and the second magnetic detection element.
  • the magnetic sensor according to the present invention may further include a nonmagnetic member that fixes magnetic materials adjacent to each other in a predetermined direction. According to this, adjacent magnetic bodies can be supported with each other without causing magnetic interference.
  • magnetism can be detected over a wide range while using a smaller sensor chip. Therefore, if the present invention is applied to a long magnetic sensor such as a magnetic sensor that scans bills in the short side direction, the cost of components can be greatly reduced.
  • FIG. 1 is a schematic perspective view showing the configuration of the magnetic sensor 100 according to the first embodiment of the present invention.
  • 2A and 2B are schematic views for explaining the internal structure of the magnetic sensor 100.
  • FIG. 2A is a schematic side view
  • FIG. 2B is a schematic top view.
  • FIG. 3 is a schematic perspective view for explaining the structure of the unit magnetic sensor 10.
  • FIG. 4 is a schematic top view for explaining the structure of the unit magnetic sensor 10.
  • FIG. 5 is a circuit diagram for explaining the connection relationship of the magnetic detection elements R1 to R4.
  • 6A and 6B are schematic views for explaining the internal structure of the magnetic sensor 200 according to the second embodiment, wherein FIG. 6A is a schematic side view and FIG. 6B is a schematic top view.
  • FIGS. 7A to 7C are diagrams showing some modified examples of the shape of the magnetic body 40.
  • FIG. 7A to 7C are diagrams showing some modified examples of the shape of the magnetic body 40.
  • FIG. 7A to 7C are diagrams showing
  • FIG. 1 is a schematic perspective view showing a configuration of a magnetic sensor 100 according to a first embodiment of the present invention.
  • the magnetic sensor 100 is a long magnetic sensor whose longitudinal direction is the x direction, and includes a detection head 110 that forms an xy plane. Then, when a member to be measured (not shown) moving in the y direction passes through the detection head 110, a magnetic pattern provided on the member to be measured can be scanned.
  • the member to be measured includes a bill.
  • the scan direction of the bill may be either the short side direction or the long side direction, but in order to scan in the short side direction, the length of the detection head 110 in the x direction is set to the length of the long side direction of the bill. More than that. In this case, the length of the detection head 110 in the x direction is, for example, about a dozen centimeters.
  • the magnetic sensor 100 has a configuration in which a plurality of unit magnetic sensors 10 are arranged in the x direction inside a housing 120.
  • FIG. 1 shows six unit magnetic sensors 10 as an example, but the present invention is not limited to this.
  • the number of unit magnetic sensors 10 constituting the magnetic sensor 100 may be appropriately determined according to the length of the detection head 110 in the x direction and the length of each unit magnetic sensor 10 in the x direction. For example, if the length of the detection head 110 in the x direction is about 18 cm and the length of each unit magnetic sensor 10 in the x direction is about 1 cm, 18 unit magnetic sensors 10 may be used.
  • the length of the detection head 110 in the x direction is determined by the size of the target member to be measured, and the length of each unit magnetic sensor 10 in the x direction is determined by the required resolution.
  • FIG. 2 is a schematic diagram for explaining the internal structure of the magnetic sensor 100, where (a) is a schematic side view and (b) is a schematic top view.
  • a substrate 20 having a longitudinal direction in the x direction is disposed inside the magnetic sensor 100, and a plurality of unit magnetic sensors 10 are mounted on the surface of the substrate 20.
  • the unit magnetic sensor 10 includes a sensor chip 30 having a magnetic detection element and a magnetic body 40 fixed to the sensor chip 30.
  • the magnetic body 40 is a plate-shaped rectangular parallelepiped made of a high permeability material such as ferrite, and plays a role of collecting magnetic flux in the sensor chip 30.
  • the two magnetic bodies 40 adjacent to each other in the x direction are not in contact with each other and are separated through a slight gap G.
  • the length of the sensor chip 30 in the x direction is sufficiently smaller than the length of the magnetic body 40 in the x direction. Therefore, the two sensor chips 30 adjacent in the x direction are sufficiently separated from each other.
  • the width of the magnetic body 40 in the y direction is sufficiently smaller than the width of the sensor chip 30 in the y direction.
  • the gap G is a part where the magnetic pattern cannot be detected or the detection sensitivity is greatly reduced. Therefore, the width of the gap G in the x direction is preferably designed to be as narrow as possible. However, when two magnetic bodies 40 adjacent in the x direction come into contact with each other, magnetic interference occurs between the unit magnetic sensors 10, and therefore it is necessary to lay out so that they do not come into direct contact with each other.
  • FIG. 3 and 4 are views for explaining the structure of the unit magnetic sensor 10, FIG. 3 is a schematic perspective view, and FIG. 4 is a schematic top view.
  • the substrate 20 has a mounting area 21, and the unit magnetic sensor 10 is mounted in the mounting area 21.
  • the unit magnetic sensor 10 includes a sensor chip 30 having a substantially rectangular parallelepiped shape and a plate-like magnetic body 40 having a longitudinal direction in the x direction.
  • Four magnetic detection elements R1 to R4 and a plurality of terminal electrodes 32 are formed on the element forming surface 31 which is the upper surface of the sensor chip 30, and these terminal electrodes 32 are provided on the substrate 20 via bonding wires BW. Connected to the terminal electrode 22.
  • the magnetic detection elements R1 to R4 it is preferable to use magnetoresistive elements (MR elements) whose electric resistance changes according to the direction of the magnetic field.
  • MR elements magnetoresistive elements
  • a plate-like magnetic body 40 is fixed to the element forming surface 31 of the sensor chip 30.
  • the magnetic body 40 is disposed between the magnetic detection elements R1 and R3 and the magnetic detection elements R2 and MR4.
  • the magnetic detection elements R1 and R3 have the same position in the y direction, and the magnetic detection elements R2 and R4 have the same position in the y direction.
  • the magnetic detection elements R1 and R4 have the same position in the x direction, and the magnetic detection elements R2 and R3 have the same position in the x direction.
  • the magnetic body 40 plays a role of collecting magnetic flux in the vertical direction (z direction), and the magnetic flux collected by the magnetic body 40 is distributed substantially evenly in the y direction. For this reason, the magnetic flux in the vertical direction is almost equally applied to the magnetic detection elements R1 to R4.
  • FIG. 5 is a circuit diagram for explaining the connection relationship of the magnetic detection elements R1 to R4.
  • the magnetic detection elements R1 and R2 are connected in series between a terminal electrode 32 supplied with a power supply potential Vdd and a terminal electrode 32 supplied with a ground potential Gnd.
  • the magnetic detection elements R3 and R4 are also connected in series between the terminal electrode 32 to which the power supply potential Vdd is supplied and the terminal electrode 32 to which the ground potential Gnd is supplied.
  • the potential Va at the connection point between the magnetic detection element R1 and the magnetic detection element R2 is output to the outside via a predetermined terminal electrode 32, and the potential Vb at the connection point between the magnetic detection element R3 and the magnetic detection element R4 is another terminal. Output to the outside via the electrode 32.
  • the magnetic detection elements R1 and R3 are arranged on one side (upper side in FIG. 4) as viewed from the magnetic body 40 in plan view, and the magnetic detection elements R2 and R4 are on the other side (in FIG. 4 in view of the magnetic body 40). Therefore, the magnetic detection elements R1 to R4 constitute a differential bridge circuit, and the change in the electric resistance of the magnetic detection elements R1 to R4 according to the magnetic flux density can be detected with high sensitivity. It becomes possible.
  • the magnetic detection elements R1 to R4 all have the same magnetization fixed direction, the resistance change amount of the magnetic detection elements R1 and R3 positioned on one side when viewed from the magnetic body 40 in a plan view and the plane There is a difference between the resistance change amounts of the magnetic detection elements R2 and R4 located on the other side when viewed from the magnetic body 40. This difference is amplified by the differential bridge circuit shown in FIG. However, in the present invention, it is not essential to use the four magnetic detection elements R1 to R4. For example, two magnetic detection elements (R1 and R4) may be used.
  • a plurality of unit magnetic sensors 10 having such a configuration are arranged in the x direction. Since the length of the magnetic body 40 included in the unit magnetic sensor 10 in the x direction is sufficiently longer than the length of the sensor chip 30 in the x direction, the entire width in the x direction is used while using a smaller sensor chip 30. Can be scanned. Usually, since the sensor chip 30 is manufactured using a collective substrate, the smaller the size, the greater the number of sensor chips 30 that can be taken from one collective substrate, thereby reducing the cost. According to the magnetic sensor 100 according to the present embodiment, since the scan width in the x direction of the unit magnetic sensor 10 is secured by the magnetic body 40, the size of the sensor chip 30 in the x direction can be further reduced. Become. Thereby, compared with the conventional long type magnetic sensor, it becomes possible to reduce part cost significantly.
  • FIG. 6A and 6B are schematic views for explaining the internal structure of the magnetic sensor 200 according to the second embodiment, wherein FIG. 6A is a schematic side view and FIG. 6B is a schematic top view.
  • the magnetic sensor 200 according to the present embodiment is different from the magnetic sensor 100 according to the first embodiment in that it further includes a nonmagnetic member 50 that fixes two magnetic bodies 40 adjacent to each other in the x direction. It is different. Since other configurations are the same as those of the magnetic sensor 100 according to the first embodiment, the same elements are denoted by the same reference numerals, and redundant description is omitted.
  • the nonmagnetic member 50 is made of, for example, resin, and serves to fix and connect two magnetic bodies 40 adjacent in the x direction. For this reason, even when the length of the magnetic body 40 in the x direction is long, the magnetic body 40 can be supported more stably. Moreover, since it is made of a material having low magnetic permeability such as resin, magnetic interference between different unit magnetic sensors 10 does not occur.
  • FIG. 7 (a) to 7 (c) are diagrams showing some modified examples of the shape of the magnetic body 40.
  • FIG. 7 (a) to 7 (c) are diagrams showing some modified examples of the shape of the magnetic body 40.
  • the magnetic body 40 shown in FIG. 7A has a flat upper surface, while the lower surface has a step, and the portion that contacts the sensor chip 30 has a high height in the z direction and does not contact the sensor chip 30. Has a shape with a low height in the z direction. Thereby, the magnetic flux collected by the magnetic body 40 can be concentrated by the sensor chip 30.
  • the magnetic body 40 shown in FIG. 7B has a shape in which the lower surface is flat, while the upper surface is curved, and the height in the z direction increases as it approaches the end in the x direction. As a result, as the distance in the x direction from the sensor chip 30 increases, the magnetic collection effect by the magnetic body 40 increases, so that it is expected to obtain a flat detection characteristic in the x direction.
  • the magnetic body 40 shown in FIG. 7C has a shape in which the upper and lower surfaces are both flat, while the thickness in the y direction increases as it approaches the end in the x direction. As a result, as the distance in the x direction from the sensor chip 30 increases, the magnetic collection effect by the magnetic body 40 increases, so that it is expected to obtain a flat detection characteristic in the x direction.

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Magnetic Variables (AREA)
  • Inspection Of Paper Currency And Valuable Securities (AREA)
  • Hall/Mr Elements (AREA)
PCT/JP2018/011971 2017-04-28 2018-03-26 磁界センサ WO2018198627A1 (ja)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201880027973.0A CN110546524A (zh) 2017-04-28 2018-03-26 磁场传感器

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2017089391A JP2018189388A (ja) 2017-04-28 2017-04-28 磁界センサ
JP2017-089391 2017-04-28

Publications (1)

Publication Number Publication Date
WO2018198627A1 true WO2018198627A1 (ja) 2018-11-01

Family

ID=63920440

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/011971 WO2018198627A1 (ja) 2017-04-28 2018-03-26 磁界センサ

Country Status (3)

Country Link
JP (1) JP2018189388A (zh)
CN (1) CN110546524A (zh)
WO (1) WO2018198627A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113474670A (zh) * 2019-02-25 2021-10-01 Tdk株式会社 磁传感器及其制造方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10293121A (ja) * 1997-04-17 1998-11-04 Sumitomo Metal Ind Ltd 微小きずの検出性能に優れた磁気探傷センサ
JP2002195984A (ja) * 2000-10-18 2002-07-10 Kawasaki Steel Corp 磁気探傷装置の漏洩磁気検出センサ
JP2005300228A (ja) * 2004-04-07 2005-10-27 Murata Mfg Co Ltd 長尺型磁気センサ
WO2013121870A1 (ja) * 2012-02-13 2013-08-22 株式会社村田製作所 磁気センサ装置
US20150300840A1 (en) * 2012-11-29 2015-10-22 International Business Machines Corporation Position sensor
JP2016173317A (ja) * 2015-03-17 2016-09-29 エスアイアイ・セミコンダクタ株式会社 半導体装置
US20160377691A1 (en) * 2015-06-26 2016-12-29 Stmicroelectronics S.R.L. Integrated amr magnetoresistor with large scale

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2921262B2 (ja) * 1992-06-04 1999-07-19 株式会社村田製作所 長尺型磁気センサ
US9411024B2 (en) * 2012-04-20 2016-08-09 Infineon Technologies Ag Magnetic field sensor having XMR elements in a full bridge circuit having diagonal elements sharing a same shape anisotropy
CN103852592A (zh) * 2012-12-05 2014-06-11 北京嘉岳同乐极电子有限公司 磁传感器芯片、磁传感器、测速方法及测距方法
JP6460372B2 (ja) * 2014-06-04 2019-01-30 Tdk株式会社 磁気センサ及びその製造方法、並びにそれを用いた計測機器
WO2016080470A1 (ja) * 2014-11-18 2016-05-26 日立金属株式会社 磁気センサ及びその製造方法並びにそれを用いた電流量検出器

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10293121A (ja) * 1997-04-17 1998-11-04 Sumitomo Metal Ind Ltd 微小きずの検出性能に優れた磁気探傷センサ
JP2002195984A (ja) * 2000-10-18 2002-07-10 Kawasaki Steel Corp 磁気探傷装置の漏洩磁気検出センサ
JP2005300228A (ja) * 2004-04-07 2005-10-27 Murata Mfg Co Ltd 長尺型磁気センサ
WO2013121870A1 (ja) * 2012-02-13 2013-08-22 株式会社村田製作所 磁気センサ装置
US20150300840A1 (en) * 2012-11-29 2015-10-22 International Business Machines Corporation Position sensor
JP2016173317A (ja) * 2015-03-17 2016-09-29 エスアイアイ・セミコンダクタ株式会社 半導体装置
US20160377691A1 (en) * 2015-06-26 2016-12-29 Stmicroelectronics S.R.L. Integrated amr magnetoresistor with large scale

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113474670A (zh) * 2019-02-25 2021-10-01 Tdk株式会社 磁传感器及其制造方法
CN113474670B (zh) * 2019-02-25 2023-11-21 Tdk株式会社 磁传感器及其制造方法

Also Published As

Publication number Publication date
CN110546524A (zh) 2019-12-06
JP2018189388A (ja) 2018-11-29

Similar Documents

Publication Publication Date Title
JP6610178B2 (ja) 磁気センサ
US10859642B2 (en) Magnetic sensor
CN104204835B (zh) 磁性传感器装置
JP6822127B2 (ja) 磁気センサ
US11567148B2 (en) Magnetic sensor
JP7115242B2 (ja) 磁気センサ
JP6941972B2 (ja) 磁気センサ
JP7095350B2 (ja) 磁気センサ
WO2018198627A1 (ja) 磁界センサ
US10168396B2 (en) Low fly height in-plane magnetic image sensor chip
JP7192227B2 (ja) 磁気センサ
JP6969397B2 (ja) 磁気センサ
JP2019219293A (ja) 磁気センサ
WO2017077871A1 (ja) 磁気センサ
JP2020071096A (ja) 磁気センサ
JP7047610B2 (ja) 磁気センサ
JP6973090B2 (ja) 磁気センサ
JP7077679B2 (ja) 磁気センサ
JP2020071095A (ja) 磁気センサ
JP7119351B2 (ja) 磁気センサ
JP2022143682A (ja) 磁気センサ
JP2023046269A (ja) 磁気センサ
JP2022152036A (ja) 磁気センサ
JP2022152037A (ja) 磁気センサ
JP2004264032A (ja) ショックセンサ

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18792292

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18792292

Country of ref document: EP

Kind code of ref document: A1