WO2014005431A1

WO2014005431A1 - Chip-type magnetic sensor

Info

Publication number: WO2014005431A1
Application number: PCT/CN2013/071561
Authority: WO
Inventors: 时启猛; 刘乐杰; 曲炳郡
Original assignee: 北京磊岳同泰电子有限公司
Priority date: 2012-07-06
Filing date: 2013-02-08
Publication date: 2014-01-09
Also published as: CN104471355A; CN104471355B

Abstract

A chip-type magnetic sensor comprises a chip (12) and a circuit board (13). The chip (12) is used for generating a differential signal based on a sensed magnetic signal of an anti-counterfeiting identifier in an object under detection; and the chip (12) is fixed to the circuit board (13), and the output end of the chip (12) is electrically connected to the wiring arranged on the circuit board (13). The chip-type magnetic sensor also comprises an anti-interference device (14) on which a magnetic vacuum area is arranged. The chip (12) is arranged in the magnetic vacuum area, and the sensing surface of the chip (12) is directed toward the object under detection. The chip-type magnetic sensor has a high signal-to-noise ratio and sensitivity and a small volume, and is easy to integrate.

Description

Chip type magnetic sensor

The invention belongs to the field of microelectronics, and in particular relates to a chip type magnetic sensor for detecting an anti-counterfeiting mark. Background technique

Changes in external factors such as current, stress strain, temperature, and light can generate a magnetic field that can cause changes in the magnetic properties of the magnetic sensing element. The magnetic property change amount of the magnetosensitive element is converted into an electric signal, and the electric signal is measured to know whether there is a current, strain, temperature, or light capable of generating a magnetic field in the region to be measured. The magnetic sensor is a measuring device developed by utilizing the above characteristics of the magnetic sensor, and is widely used in the fields of finance, aviation, aerospace, microelectronics, geological prospecting, medical imaging, information acquisition, and military.

In the industrial field, the most widely used magnetic sensor is a coil type magnetic sensor, that is, a coil is a magnetic sensor. Figure 1 is a structural diagram of a magnetic sensor currently used in the financial field. As shown in Fig. 1, the magnetic sensor includes a housing 101, a coil 109, and a printed circuit board 113, and an opening 103 is provided at the top end of the housing 101. At the center of the collar of the cores 05a, 105b, a narrow magnetic gap 107 is provided, and the cores 105a, 105b are fixed in the casing 101 by the bracket 111, and the top end thereof projects from the opening 103 of the casing 101. A plurality of turns of the coil are wound around the bottom ends of the cores 105a, 105b, and the coil 109 is connected to the printed circuit board 113, and the printed circuit board 113 is connected to other components provided outside the shield case 101 by the solder pins 114a, 114. At the time of banknote verification, the banknote magnetic ink strip or magnetic metal strip is drawn from the top ends of the magnetic cores 105a, 105b, and the magnetic gap 107 causes an induced electromotive force corresponding to the magnetic field strength ratio of the banknote magnetic ink strip or the magnetic metal strip in the coil 109. According to the induced electromotive force, the authenticity of the ticket can be discriminated.

As market demand changes, magnetic sensors are gradually becoming smaller and more integrated. The coil type magnetic sensor is bulky, heavy, and has a slow response, low resolution, low sensitivity, and poor reliability. More What is important is that the coil type magnetic sensor has poor anti-interference ability, is easily interfered by other magnetic fields, and reduces the reliability of the magnetic sensor. In other words, the existing coil type magnetic sensor cannot meet the above-mentioned demand for the magnetic sensor in the market, and thus it is urgent to develop a magnetic sensor which is strong in anti-interference ability, small in size, easy to integrate, and high in sensitivity. Summary of the invention

The technical problem to be solved by the present invention is to provide a chip type magnetic sensor and a manufacturing method thereof for the above-mentioned defects existing in the magnetic sensor, which have strong anti-interference ability, small volume, high sensitivity and easy integration.

To this end, the present invention provides a chip type magnetic sensor, comprising:

a chip for generating a differential signal based on the sensed magnetic signal of the anti-counterfeit mark in the object to be measured;

a circuit board, the chip is fixed to the circuit board, and an output end of the chip is electrically connected to a wiring provided on the circuit board;

The anti-jamming device is configured with a magnetic vacuum region on the anti-jamming device, the chip is placed in the magnetic vacuum region, and the sensing surface of the chip faces the object to be measured.

The anti-jamming device includes a permanent magnet body made of a permanent magnet material, and a plurality of convex portions are formed on the permanent magnet body, and the plurality of convex portions are distributed along the circumferential direction of the permanent magnet body. The permanent magnet body extends toward the side of the object to be measured, and the magnetic vacuum region is formed between the protrusions.

Wherein, the plurality of convex portions are evenly distributed along the circumferential direction of the permanent magnet body.

The protrusions are continuously distributed along the circumferential direction of the permanent magnet body.

Wherein, a plurality of tooth portions are provided on opposite sides of the HJ portion, and the plurality of tooth portions are spaced apart, and a magnetic vacuum sub-region is formed between the two adjacent tooth portions.

Wherein, a film layer is formed on the surface of the concave portion and the tooth portion, and the film layer is formed of metal, non-metal or gas. Wherein the chip and the circuit board are placed in a magnetic vacuum sub-region between the protrusions. Wherein the circuit board is provided with a circuit board through hole that cooperates with the convex portion, the convex portion passes through the circuit board through hole from one side of the circuit board and from the circuit board The other side protrudes, and the top end of the convex portion is flush with the sensing surface of the chip or higher than the sensing surface of the chip.

The anti-interference device includes a permanent magnet body made of a permanent magnet material, and a permanent magnet body through hole is disposed in the permanent magnet body, and the magnetic vacuum region is formed in the through hole of the permanent magnet body. One end of the permanent magnet body through hole is opposite to the object to be measured, and the chip and the circuit board are placed on the surface of the permanent permanent magnet body.

Wherein, the permanent magnet body is made of ferrite, permalloy or silicon steel sheet; or the permanent magnet body is made of neodymium iron boron, samarium cobalt or aluminum nickel cobalt, or made of metal material or non-metal material; And add a coating of ferronickel or permalloy on its outer surface.

Wherein the anti-jamming device comprises a winding and a power source, the power source supplies electric energy to the winding, the magnetic vacuum region is formed inside the winding, and an end of the winding is opposite to the object to be measured.

The anti-interference device includes a magnetic field generating unit and a magnetic conductive unit, wherein the magnetic field generating unit is configured to generate a magnetic field; the magnetic conductive unit is disposed within a magnetic field generated by the magnetic field generating unit, and the magnetic vacuum region is formed. Within the magnetically permeable unit.

The magnetic conductive unit includes a magnetic conductive body made of a magnetically permeable material, and a plurality of convex portions are disposed on the magnetic conductive body, and the plurality of convex portions are distributed along the circumferential direction of the magnetic conductive body. The magnetically conductive body extends toward the side of the object to be measured, and the magnetic vacuum region is formed between the convex portions.

Wherein, two oppositely disposed protrusions are formed on the magnetically permeable body, and the chip is disposed between the two protrusions.

Wherein the convex portions are continuously distributed along a circumferential direction of the magnetic conductive body.

Wherein the chip and the circuit board are placed between the convex portions. Wherein the circuit board is provided with a circuit board through hole that cooperates with the convex portion, and the convex portion of the magnetic conductive unit passes through the circuit board through hole from one side of the circuit board and The other side of the circuit board protrudes, and the top end of the convex portion is flush with the sensing surface of the chip or higher than the sensing surface of the chip.

The magnetic conductive unit includes a magnetically conductive body made of a magnetically permeable material, and a magnetically conductive body through hole is disposed in the magnetically permeable body, and the magnetic vacuum region is formed in the through hole of the magnetic conductive body, One end of the conductive body through hole is opposite to the object to be measured, and the chip and the circuit board are placed on the surface of the through hole.

Wherein, the magnetic field generating unit is a permanent magnet made of ferrite, permalloy or silicon steel sheet.

The magnetic field generating unit includes a winding and a power source, and the power source supplies electric power to the winding; the magnetic conductive unit is disposed inside the winding or at an end of the winding.

The magnetic vacuum region is filled with a gas containing magnetic particles, and the gas containing the magnetic particles flows in the magnetic vacuum region to form a magnetic eddy current.

Wherein the chip comprises at least one pair of magnetic sensitive films and chip pads electrically connected to the magnetic sensitive film, the at least one pair of magnetic sensitive films forming a benefit by means of the die pads and wiring on the circuit board Stone bridge circuit.

Wherein, in the longitudinal direction of the magnetic sensitive film, there are provided n suppressing units for segmentally suppressing the demagnetizing field of the magnetic sensitive film, the suppressing unit being spaced apart from the surface of the magnetic sensitive film and/or Internal, where 11 is an integer > 2 .

Wherein, the suppression unit is made of a conductive material.

The magnetic sensitive film is a Hall effect film, an anisotropic magnetoresistance film giant magnetoresistive film, a tunnel magnetoresistance film, a giant magnetoimpedance film or a giant Hall effect film.

The chip-type magnetic sensor further includes a housing, a processing unit, and a soldering pin, wherein the processing unit is configured to identify the anti-counterfeiting identifier according to the differential signal; The chip and the circuit board are disposed in the housing; the processing unit is disposed in the housing or outside the housing;

The solder pins are electrically connected to wires on the circuit board for transmitting signals and supporting the housing.

Wherein, the circuit board is a hard resin material matrix circuit board or a flexible matrix circuit board. Wherein, a magnetic conductive hole is disposed on the housing, and the chip is opposite to the magnetic conductive hole.

Wherein, the housing is made of copper, iron or plastic.

Wherein, the shell is made of permalloy, ferrite or galvanic sheet; or it is made of metal or non-metal material, and a nickel-iron or permalloy coating is provided on the outer surface thereof.

The invention has the following beneficial effects:

The chip-type magnetic sensor provided by the invention comprises an anti-interference device capable of forming a magnetic vacuum region, the chip is placed in a magnetic vacuum region of the anti-jamming device, and the sensing surface of the chip faces the anti-counterfeit mark carried by the object to be measured, such that Only the magnetic lines perpendicular to or close to the sensing surface perpendicular to the chip can enter the magnetic vacuum region and be sensed by the chip, and the magnetic lines in other directions are blocked outside the magnetic vacuum region, so that the sensitivity can be effectively avoided without loss of sensitivity. It suppresses or even eliminates noise and interference such as electrical signals or magnetic signals in the surrounding environment, thereby improving the signal-to-noise ratio and sensitivity of the magnetic sensor. In addition, the chip is used as a magnetic sensitive component, which is small in size, easy to integrate, and high in sensitivity, so that the volume of the magnetic sensor including the magnetic sensitive component can be reduced and integration is easy, and the sensitivity of the magnetic sensor can be improved. DRAWINGS

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from

Figure 1 is a structural diagram of a magnetic sensor currently used in the financial field;

2a is a structural diagram of a chip type sensor according to Embodiment 1 of the present invention;

Figure 2b is an exploded view of the chip type magnetic sensor shown in Figure 2a; 2c is a structural diagram of a chip used in the chip type magnetic sensor shown in FIG. 2a; and FIG. 2d is an electrical connection diagram of a processing unit and a chip in the chip type magnetic sensor shown in FIG. 2a;

Figure 3 is a structural view of a first type of anti-jamming device applicable to the chip type magnetic sensor shown in Figure 2a;

Figure 4 is a simulation diagram of the magnetic field distribution of the first type of anti-jamming device shown in Figure 3;

Figure 5a is a structural view of a second anti-interference device applicable to the chip type magnetic sensor shown in Figure 2a;

Figure 5b is a structural view of a third anti-interference device applicable to the chip type magnetic sensor shown in Figure 2a;

Figure 5c is a structural view of a fourth anti-1000 device applicable to the chip type magnetic sensor shown in Figure 2a;

Figure 5d is a structural view of a fifth anti-jamming device applicable to the chip type magnetic sensor shown in Figure 2a;

Figure 5e is a structural view of a sixth anti-jamming device applicable to the chip type magnetic sensor shown in Figure 2a;

Figure 5f is a structural view of a seventh anti-jamming device applicable to the chip type magnetic sensor shown in Figure 2a;

Figure 5g is a structural view of an eighth anti-interference device applicable to the chip type magnetic sensor shown in Figure 2a;

Figure 6a is a structural view of a ninth anti-jamming device applicable to the chip type magnetic sensor shown in Figure 2a;

Figure 6b is a structural diagram of a tenth anti-throw device applicable to the chip type magnetic sensor shown in Figure 2a;

Figure 7a is a partial structural view of a chip-type magnetic sensor according to a second embodiment of the present invention; Figure 7b is a partial structural view of a chip-type magnetic sensor according to a third embodiment of the present invention; Figure 7c is a partial structural view of a chip-type magnetic sensor according to a fourth embodiment of the present invention; Figure 7a is a partial structural view of a chip-type magnetic sensor according to a fifth embodiment of the present invention; a perspective view of a partial structure of the magnetic sensor; FIG. 8b is a top view of the chip type magnetic sensor shown in FIG. 8a;

Figure 8c is a cross-sectional view taken along line A A of Figure 8b;

9 is a cross-sectional view showing a chip type magnetic sensor according to Embodiment 7 of the present invention;

10 is an exploded view of a chip type magnetic sensor according to Embodiment 8 of the present invention;

Figure 11a is a perspective view of a chip type magnetic sensor according to Embodiment 9 of the present invention;

Figure l ib is an exploded view of the chip type magnetic sensor provided in Embodiment 9 of the present invention;

Fig. 12 is a view showing a manner of detecting a chip type magnetic sensor according to an embodiment of the present invention. detailed description

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the chip type magnetic sensor provided by the present invention will be described in detail below with reference to the accompanying drawings.

2a is a structural view of a chip type magnetic sensor according to Embodiment 1 of the present invention; and FIG. 2b is an exploded view of the chip type magnetic sensor shown in FIG. 2a. As shown in Figs. 2a and 2b, the chip type magnetic sensor includes a housing 11, a chip 12, a wiring board 13, an anti-jamming device 14, a soldering pin 15, and a processing unit (not shown). The chip 12 is used to sense an anti-counterfeit mark in the object to be tested, and is fixed to the circuit board 13. A magnetic vacuum region is provided on the anti-jamming device 14, and the chip 12 is placed in the magnetic vacuum region and the sensing surface of the chip 12 faces the object to be measured. The chip 12, the wiring board 13, and the anti-drying device 14 are disposed in the casing 11, and are connected to other components provided outside the casing 11 by the welding pins 15. A ground terminal 18 may also be provided on the housing 11, and the housing 11 is grounded through the ground terminal 18. The housing 11 is made of copper, iron or plastic.

Fig. 2c is a structural view of a chip used in the chip type magnetic sensor shown in Fig. 2a. As shown in FIG. 2c, the chip 12 includes a pair of magnetic sensitive films 411 and a chip electrically connected to the magnetic sensitive film 411. The pad 412 includes two magnetic sensitive films 411 disposed at the ends of the magnetic sensitive film 411. The die pads 412 are for electrically connecting the magnetic sensitive film 411 and the wiring on the circuit board 13, by means of the chip. The pad 412 and the wiring connect the magnetic sensitive film 411 into a Wheatstone half bridge circuit. The Wheatstone half-bridge circuit senses the influence of external magnetic signals and generates a differential voltage signal (hereinafter referred to as "differential signal"). Of course, the chip 12 may also include two or more pairs of magnetic sensitive films 411 that connect the magnetic sensitive film 411 to a Wheatstone half bridge circuit or a Wheatstone full bridge circuit. In other words, the chip 12 includes at least one pair of magnetic sensitive films 411 as long as the magnetic sensitive film 411 is connected to a Wheatstone half bridge or a Wheatstone full bridge circuit. The magnetic sensitive film 411 may be a Hall effect film, an anisotropic magnetoresistance film, a giant magnetoresistance film, a tunnel magnetoresistance film, a giant magnetoimpedance film or a giant Hall effect film.

In the longitudinal direction of each of the magnetic sensitive films 411, n suppression units may be spaced apart for suppressing the demagnetizing field of the magnetic sensitive film 411, wherein 11 is an integer of >2. The suppressing unit is made of a conductive material which is provided on the surface and/or the inside of the magnetic sensitive film 411 to form a short circuit in the magnetic sensitive film 411, thereby suppressing the demagnetizing field of the magnetic sensitive film 411. The suppression unit can improve the measurement accuracy of the chip 12, thereby improving the sensitivity and accuracy of the chip type magnetic sensor.

The circuit board 13 employs a printed circuit board, and the circuit board 13 is electrically connected to the chip 12 for transporting the differential signals obtained by the chip 12. The wiring board 13 may be a hard resin material matrix circuit board or a flexible substrate circuit board. In the present embodiment, the circuit board 13 is made of a hard resin material matrix circuit board, and the chip 12 is fixed to the circuit board 13, and the chip 12 and the circuit board 13 are disposed in the casing 11.

The processing unit is configured to identify the anti-counterfeit identification according to the differential signal generated by the chip 12, for example, whether the anti-counterfeit identification, the size of the anti-counterfeit identification, or the magnetic field size of the anti-counterfeit identification is present. The processing unit may be disposed within the housing 11, such as on the circuit board 13; or may be disposed outside of the housing 11. In order to filter out the noise in the differential signal outputted by the chip 12, the processing unit may include a filter circuit, and the input end of the filter circuit is connected to the signal output end of the chip 12, thereby achieving the purpose of filtering the noise in the differential signal output by the chip 12, As shown in Figure 2d.

The solder pin 15 is electrically connected to the circuit board 13 for transmitting differential signals and supporting the housing 11. 3 is a structural view of a first type of anti-jamming device applicable to the chip type magnetic sensor shown in FIG. 2a. As shown in FIG. 3, the anti-jamming device 14 includes a permanent magnet body 31 made of a permanent magnet material, and the permanent magnet material may be a ferrite, a permalloy or a silicon steel sheet. A convex portion 32 is disposed at each of opposite ends of the permanent magnet body 31. The convex portion 32 changes the magnetic field distribution generated by the permanent magnet body 31, that is, the magnetic lines of force generated by the permanent magnet body 31 are concentrated toward the convex portion 32, thereby A magnetic vacuum region is formed between the two convex portions 32, and the magnetic field of the magnetic vacuum region is weak relative to the magnetic field around it, even close to zero. Therefore, the magnetic vacuum region is also considered to be a zero magnetic region. The chip 12 is disposed between the two convex portions 32, and the sensing surface of the chip 12 faces the object to be measured. Preferably, the sensing surface of the chip 12 is lower or flush with the top end of the convex portion 32, so that the magnetic signal not perpendicular to the sensing surface of the chip 12 can be shielded as much as possible, thereby improving the anti-interference ability of the chip sensor. In turn, the reliability of the chip sensor is improved.

The magnetic vacuum region of this embodiment is surrounded by the magnetic field generated by the permanent magnet body 31, and only magnetic lines perpendicular to the concave portion 33 can enter the magnetic vacuum region. As shown in FIG. 4, due to the influence of the magnetic field generated by the permanent magnet body 31, only the magnetic lines of force perpendicular to the concave portion 33 can enter the magnetic vacuum region Z among the magnetic lines of force generated by the external magnetic field S, while the magnetic lines of force in other directions are subjected to the permanent magnet body. 3] The influence of the generated magnetic field is parallel to the magnetic lines of force of the permanent magnet body 31, that is, the magnetic lines of force generated by the external magnetic field S that are not perpendicular to the other direction of the recess 33 are shielded by the magnetic field generated by the permanent magnet body 31. The magnetic vacuum region in this embodiment makes the magnetic sensitivity direction of the sensor perpendicular or parallel to the magnetic field of the permanent magnet body 31, thereby suppressing or even eliminating noise interference such as electrical signals and magnetic signals in the external environment, thereby improving the chip type. Magnetic sensor's anti-interference ability and signal-to-noise ratio.

In the present embodiment, the permanent magnet body 31 is constructed with two convex portions 32, but the present invention is not limited thereto. Further, a plurality of convex portions 32 may be formed on the permanent magnet body 31, and the plurality of convex portions 32 are distributed along the circumferential direction of the permanent magnet body 31, and a magnetic vacuum region is formed between the convex portions 32. Preferably, the plurality of convex portions 32 are uniformly distributed along the circumferential direction of the permanent magnet body 31, and extend from the permanent magnet body 31 toward the side of the object to be measured to obtain a magnetic vacuum region of a desired shape, thereby reducing the anti-interference device The volume of 14. As shown in FIG. 5a, in the second anti-jamming device applicable to the chip type magnetic sensor shown in FIG. 2a, four convex portions 32 are uniformly and symmetrically configured in the circumferential direction of the permanent magnet body 31, four The convex portion 32 can influence The magnetic flux lines generated by the permanent magnet body 31 are distributed, and a magnetic vacuum region is formed between the four convex portions 32. In use, the permanent magnet body 3 1 is disposed in the housing 1 1 with the convex portion 32 facing the object to be measured; the chip 12 is placed in the magnetic vacuum region between the convex portions 32, and the sensing surface of the chip 12 faces the object to be measured.

Fig. 5b is a structural view of a third anti-jamming device applicable to the chip type magnetic sensor shown in Fig. 2a. As shown in Fig. 5b, the anti-jamming device includes a permanent magnet body 3 1 made of a permanent magnet, and a concave portion 33 is provided on the surface of the permanent magnet body 31, that is, the convex portion is continuous in the circumferential direction of the permanent magnet body. The magnetic lines of force generated by the permanent magnet body 3 1 are concentrated toward the convex portion, thereby forming a magnetic vacuum region in the concave portion 33. In use, the permanent magnet body 3 1 is disposed in the housing 1 1 and the recess 33 faces the object to be measured. The chip 12 is placed in the recess 33, and the sensing surface of the chip 12 faces the object to be measured. Preferably, the sensing surface of the chip 12 is lower than or flush with the upper surface of the permanent magnet body 31 to shield the magnetic signal that is not perpendicular to the sensing surface of the chip 12 as much as possible, thereby improving the anti-interference capability of the chip sensor. , thereby improving the reliability of the chip sensor.

In the above embodiment, the outer shape of the permanent magnet body 31 is a rectangular parallelepiped, and the shape of the lateral cross section of the concave portion 33 is a cylinder and a square. However, the invention is not limited to this. The outer shape of the permanent magnet body 31 may also be a square, a cylinder, a cone, a sphere, or a combination of any two or more of the above. In the lateral section of the permanent magnet body 31, the shape of the recess 33 may also be a circular shape, a square shape, a tapered shape or a combination of any two or two shapes. In the longitudinal section of the permanent magnet body 31, the shape of the recess 33 may also be a circular, square, tapered or a combination of any two of a circular shape, a square shape, and a tapered shape. It should be noted that the transverse section of the permanent magnet body 31 refers to the horizontal section of the permanent magnet body 31, and the longitudinal section of the permanent magnet body 31 refers to the vertical section of the permanent magnet body 31.

As shown in FIG. 5c, the anti-jamming device 14 includes a permanent magnet body 31 made of a permanent magnet material, and the permanent magnet body 31 has a cylindrical shape. In the lateral section of the permanent magnet body 31, the recess 33 has a circular shape. In the longitudinal section of the permanent magnet body 31, the shape of the recess 33 is square. In short, the permanent magnet body 3 1 and the recess 33 can form a magnetic vacuum region in the recess 33 regardless of the shape, and are within the scope of the present invention.

As shown in FIG. 5d, the anti-jamming device 14 includes a permanent magnet body 31 made of a permanent magnet material, in Yong The upper and lower end faces of the magnetic body 31 are each provided with a recess 33, so that two magnetic vacuum regions can be formed on the permanent magnet body 31, and the chip 12 is usually disposed in a magnetic vacuum region near the side of the object to be measured.

As shown in FIG. 5e, the anti-interference device 14 includes a permanent magnet body 31 made of a permanent magnet material, a concave portion 33 is disposed on the permanent magnet body 31, and eight tooth portions 34 are further disposed in the concave portion 33, and two or two The opposite arrangement, that is, four tooth portions 34 are provided on the opposite sides in the concave portion 33, and the four tooth portions 34 are spaced apart to divide the concave portion 33 into five sub-regions. The magnetic lines of force of the permanent magnet body 3 1 form a magnetic field comb through the tooth portion 34, and a plurality of magnetic true-core regions are formed in the concave portion 33. In use, the chip 12 is placed in the region of the tooth portion 34 opposite the tooth portion 34 or between two adjacent tooth portions 34.

The tooth portion 34 can be obtained in the following manner: First, the tooth portion 34 is directly machined in the permanent magnet body 31, and at this time, the tooth portion 34 and the permanent magnet body 31 are integrally formed. Secondly, the tooth portion 34 is first machined, and then the tooth portion 34 is fixed in the recess 33 by welding or other fixed connection means, and the tooth portion 34 can be oxidized by metal, metal oxide, non-metal, non-metal oxide or non-metal. The coating is made of a plating layer, and the plating layer may be made of gold, silver, copper, iron, tin or an oxide thereof; or a plating layer may be applied on the surface of the tooth portion 34. Third, the tooth portion 34 may be formed of a gas, that is, a gas vortex is formed by the gas flowing in the concave portion 33 to form a magnetic field comb such as a tooth portion 34, and the gas may be air or a gas containing magnetic particles.

In the present embodiment, when the tooth portion 34 is obtained by using a non-gas material, a film layer (not shown) is further provided on the surface of the portion 33 and the tooth portion 34, and the film layer is formed of metal, non-metal or gas. The thin film layer is used to improve the magnetic field distribution of the magnetic vacuum region and the weak magnetic region, thereby forming an ideal magnetic vacuum region in the concave portion 33, thereby effectively shielding noise signals such as external electrical signals and magnetic signals without affecting sensitivity. Improve the reliability of chip-type magnetic sensors.

Fig. 5f can be applied to the structural view of the seventh anti-dry device in the chip type magnetic sensor shown in Fig. 2a. As shown in FIG. 5f, the anti-jamming device 14 comprises a permanent magnet body 31 made of a permanent magnet material, and a permanent magnet body through hole 35 is formed on the permanent magnet body 31, and the magnetic field lines of the permanent magnet body 31 are from the permanent magnet body through hole. The permanent magnet body 31 around 35 passes through, thereby forming a magnetic vacuum region in the permanent magnet body through hole 35. The permanent magnet body through hole 35 may extend longitudinally through the permanent magnet body 31 as shown in Fig. 5f. Permanent magnet body through hole 35 It is also possible to penetrate the permanent magnet body 31 laterally. In use, one end of the permanent magnet body through hole 35 is opposed to the object to be measured, and the chip 12 is fixed in the permanent magnet body through hole 35 as close as possible to the object to be measured. Preferably, the sensing surface of the chip 12 is lower than the top end of the permanent magnet body 31, so that the magnetic signal not perpendicular to the sensing surface of the chip 12 can be shielded as much as possible, thereby improving the anti-interference ability of the chip sensor, thereby improving the chip sensor. reliability.

As a modification of the anti-jamming device shown in Fig. 5f, the anti-jamming device 14 includes a permanent magnet body 31 made of a permanent magnet material, the permanent magnet body 31 is annular in shape, and the intermediate position of the permanent magnet body 31 is a magnetic vacuum region. In use, the chip 12 is nested in the middle of the permanent magnet body 31, as shown in Fig. 5g.

Fig. 6a is a structural view of a ninth anti-interference device applicable to the chip type magnetic sensor shown in Fig. 2a. As shown in Figure 6a, the anti-jamming device 14 includes a winding 61 and a power source (not shown) that supplies electrical energy to the winding 61 to cause the winding 61 to generate an induced magnetic field. According to the Ampere's rule, there is a ring-shaped magnetic field around the energized wire, which is distributed along the toroidal winding 61 and has an approximately vortex shape, and therefore, inside the annular winding 61 (i.e., in the region surrounded by the toroidal winding 61, for example, a ring The central axis region of the winding 61) forms a magnetic vacuum region. In use, the chip 12 is placed in the central region of the toroidal winding 61, and the object to be measured is placed at the end of the toroidal winding 61. The induced magnetic field formed by the toroidal winding 61 can effectively suppress electrical noise and/or magnetic noise in the surrounding environment, thereby improving the sensitivity and signal-to-noise ratio of the chip-type magnetic sensor. It should be noted that the end of the toroidal winding 61 refers to an end face of the toroidal winding 61 which is perpendicular to the central axis of the toroidal winding 61.

In this embodiment, the toroidal winding 61 is a coil of a planar structure in which a single wire is spirally wound in the same plane, and the wound coil may be a turn, as shown in FIG. 6a; Can be more than awkward. The winding 61 can also be a coil of a planar structure in which a plurality of wires are spirally wound in the same plane, as shown in Fig. 6b. Of course, the winding 61 may also be a three-dimensional structure (three-dimensional structure) coil wound by a single wire in a spiral manner; or a three-dimensional structure coil wound by a plurality of wires in a spiral manner.

In this embodiment, an iron core (not shown) may be disposed in the coil, and the iron core may be made of neodymium iron boron, samarium cobalt, aluminum nickel cobalt or ferrite. The shape of the iron core can adopt the embodiment as described above The shape of the permanent magnet body will not be described herein. The iron core can not only optimize the distribution of the magnetic lines of the winding 61, establish a stable magnetic vacuum region, and improve the anti-interference ability of the chip-type magnetic sensor; and is used for supporting the chip 12, which is advantageous for the assembly of the chip-type magnetic sensor. In use, the chip 12 may be disposed in a recess or a through hole of the iron core, or disposed between the two convex portions, and the sensing surface of the chip 12 is lower than the surface of the iron core to shield as much as possible from the chip 12 The magnetic signal of the sensing surface; thereby improving the anti-interference ability of the chip sensor, thereby improving the reliability of the chip sensor.

FIG. 7a is a partial structural diagram of a chip type magnetic sensor according to Embodiment 2 of the present invention. As shown in Fig. 7a, the anti-jamming device 14 includes a magnetic field generating unit 71 and a magnetic conducting unit 72 for generating a magnetic field: the magnetic conducting unit 72 is superposed on top of the magnetic field generating unit 71. Preferably, the magnetic conductive unit 72 is disposed in a region where the magnetic field generating unit 71 has a strong magnetic field, but in practical applications, the magnetic conductive unit 72 may be disposed within the magnetic field generated by the magnetic field generating unit 71. The magnetic vacuum region is formed in the magnetic permeability unit 72.

The magnetic field generating unit 71 is a permanent magnet made of ferrite, permalloy or tantalum steel sheet. The magnetic conductive unit 72 includes a magnetic conductive body 74 made of a magnetically permeable material. The opposite ends of the magnetic conductive body 74 are provided with convex portions 73. The convex portions 73 change the magnetic field distribution of the magnetic conductive body 74, that is, the magnetic conductive body 74 is generated. The magnetic lines of force pass through the area of the convex portion 73 such that a magnetic vacuum is formed between the two convex portions 73, and the magnetic field of the magnetic vacuum region is weak relative to the surrounding magnetic field, even close to zero. Therefore, the magnetic vacuum region is also considered to be a zero magnetic region.

In use, the chip 12 and the wiring board 13 are disposed between the two convex portions 73, and the sensing surface of the chip 12 faces the object to be measured. Preferably, the sensing surface of the chip 12 is lower than the top end of the convex portion 73, so that the magnetic signal not perpendicular to the sensing surface of the chip 12 can be shielded as much as possible, thereby improving the anti-interference ability of the chip sensor, thereby improving the chip sensor. Reliability.

In the present embodiment, the opposite ends of the magnetic guiding body 74 are each configured with a convex portion 73, but the present invention is not limited thereto. A plurality of convex portions 73 may be formed on the magnetic conductive body 74, and a plurality of convex portions 73 are formed between the convex portions 73. In use, one end of the convex portion 73 is disposed toward the object to be measured, and the chip 12 The circuit board 13 is disposed between the convex portions 73.

FIG. 7b is a partial structural diagram of a chip type magnetic sensor according to Embodiment 3 of the present invention. As shown in Fig. 7b, the anti-interference device includes a magnetic field generating unit 71 and a magnetic conductive unit 72, wherein the magnetic field generating unit 71 is a permanent magnet made of ferrite, permalloy or silicon steel sheet. The magnetic conductive unit 72 includes a magnetic conductive body 74 made of a magnetically permeable material, and a concave portion 75 is formed on the surface of the magnetic conductive body 74. That is, the convex portions are continuously distributed in the circumferential direction of the magnetic conductive body 74, and the magnetic vacuum region is formed in the concave portion 75. In use, the magnetic body 74 is placed on top of the magnetic field generating unit 71, and the recess 75 faces the object to be measured. The chip 12 is placed on the plane of the recess 75. Preferably, the sensing surface of the chip 12 is lower than the upper surface of the magnetic guiding body 74, so that the magnetic signal not perpendicular to the sensing surface of the chip 12 can be shielded as much as possible, thereby improving the chip sensor. The anti-interference ability, which in turn improves the reliability of the chip sensor.

FIG. 7c is a partial structural diagram of a chip type magnetic sensor according to Embodiment 4 of the present invention. As shown in Fig. 7c, the magnetic conductive unit 72 includes a magnetically permeable body 74 made of a magnetically permeable material, and a magnetically permeable body through-hole 76 is formed in the magnetically permeable body 74. The magnetic vacuum region is formed in the conductive body through-hole 76. In use, one end of the conductive body through hole 76 is opposite to the object to be measured, and the chip 12 is placed in the conductive body through hole 76. Preferably, the sensing surface of the chip 12 is lower than the upper surface of the magnetic guiding body 74, so that It is possible to shield the magnetic signal that is not perpendicular to the sensing surface of the chip 12, thereby improving the anti-interference ability of the chip sensor, thereby improving the reliability of the chip sensor.

FIG. 7 is a partial structural diagram of a chip type magnetic sensor according to Embodiment 5 of the present invention. As shown in FIG. 7d, the chip type magnetic sensor includes a magnetic field generating unit 71 and a magnetic conducting unit 72, wherein the magnetic field generating unit 71 is a permanent magnet made of ferrite, permalloy or silicon steel sheet; the magnetic conducting unit 72 includes The magnetically permeable body 74 made of a magnetically permeable material is provided with convex portions 73 at opposite ends of the magnetic permeable body 74. The difference between the embodiment and the embodiment shown in FIG. 7a is that the outer peripheral edge of the magnetic field generating unit 71 is equal in size to the outer peripheral edge of the magnetic conductive unit 72, so that the magnetic field of the magnetic field generating unit 71 is mainly concentrated on the magnetic conductive unit 72. Directly below, the magnetic field strength around the magnetically permeable unit 72 can be reduced. Of course, the magnetic field produces a magnetic field strength around a single. Thus, the magnetic lines of force of the magnetic field generating unit 71 are as much as possible by the magnetic conductive unit 72. The beam is at a position corresponding to the convex portion 73, and the influence of the magnetic field generating unit 71 on the sensitivity of the chip 12 can be further reduced. Therefore, in practical applications, preferably, the chip type magnetic sensor whose outer peripheral edge size of the magnetic field generating unit 71 is smaller than or equal to the outer peripheral size of the magnetic conductive unit 72.

In the above embodiment, both the chip 12 and the wiring board 13 are disposed in the concave portion of the magnetic conductive unit 72. In another embodiment, only the chip 12 is disposed in the recessed region of the magnetically permeable unit 72.

Specifically, FIG. 8a is a perspective view showing a partial structure of a chip type magnetic sensor according to Embodiment 6 of the present invention, FIG. 8b is a plan view of the chip type magnetic sensor shown in FIG. 8a, and FIG. 8c is a cross-sectional view taken along line A A of FIG. 8b. As shown in FIG. 8a, FIG. 8b, and FIG. 8c, the chip type magnetic sensor includes a chip 12, a circuit board 13 and an anti-interference device 14 . The anti-interference device 14 includes a magnetic field generating unit 71 and a magnetic conductive unit 72, wherein the magnetic field generating unit 71 is a permanent magnet made of a ferrite, permalloy or tantalum steel sheet; the magnetic conductive unit 72 includes a magnetically permeable body 74 made of a magnetically permeable material, and convex portions 73 are provided at opposite ends of the magnetic conductive body 74. The chip 12 is disposed on the surface of the circuit board 13. The circuit board 13 is provided with a circuit board through hole 415 which is matched with the size of the convex portion 73. The circuit board through hole 415 is located at two sides of the chip 12, and the distance between the circuit board through holes 4] 5 and the convex portion 73 The distance between the matches. The convex portion 73 is inserted into the wiring board through hole 415 from the lower side of the wiring board 13, and the top end of the convex portion 73 is flush with the upper surface of the wiring board 13, so that the chip 12 is placed between the two convex portions 73. The chip type magnetic sensor has a simple structure, can simplify the processing process of the chip type magnetic sensor, and can reduce the volume of the anti-interference device 14, thereby reducing the manufacturing cost of the chip type magnetic sensor.

It is not difficult to understand that the anti-interference device 14 of the present embodiment can also be directly processed into the shape of the magnetic conductive unit 72 using a permanent magnet material, and the object of the present invention can be achieved as well. That is to say, in practical applications, the anti-interference device 14 may adopt a structure in which the magnetic field generating unit 71 and the magnetic conductive unit 72 are stacked together, as shown in FIG. 7a, FIG. 7b, FIG. 7c, FIG. 7d, FIG. 8a, and FIG. 8b and 8c; it is also possible to directly form the shape of Fig. 3, Fig. 5a, Fig. 5b, Fig. 5c, Fig. 5d, Fig. 5e or Fig. 5c using a permanent magnet material. However, it is preferable to use the former, that is, the magnetic flux unit 72 is used to restrain the distribution of the magnetic lines of force, so that the magnetic field of the magnetic field generating unit 71 is perpendicular to the detecting surface of the object to be measured, so that other magnetic fields of the outside can be more effectively reduced into the magnetic vacuum region. Figure 9 is a cross-sectional view showing a chip type magnetic sensor according to a seventh embodiment of the present invention. As shown in FIG. 9, the chip type magnetic sensor includes a housing 11, a chip 12, a wiring board 13, and an anti-jamming device 14, and the chip 12, the wiring board 13, and the anti-interference device 14 are placed in the casing 11.

The anti-jamming device 14 includes a magnetic field generating unit 71 and a magnetic conducting unit 72. Wherein, the magnetic field generating unit comprises a winding 711 and a power source (not shown), and the power source supplies electric power to the winding 711 to cause the winding 711 to generate an induced magnetic field. According to Ampere's law, a toroidal magnetic field is present around the energized conductor, and the toroidal magnetic field is distributed along the toroidal winding 711 and is approximately vortex-like, and a magnetic vacuum region is formed in the central axis region of the toroidal winding 711. The magnetic conductive unit 72 has a U-shaped structure, that is, the magnetic conductive unit 72 includes a magnetic conductive body 721 and a convex portion 722, and the two convex portions 722 are oppositely disposed at both ends of the magnetic conductive body 721. The winding 711 is wound around the convex portion 722 of the magnetic conductive unit 72, and a winding 711 is wound around each convex portion 722.

In this embodiment, three or more convex portions 722 may be further formed on the magnetic conductive body 721, and the plurality of convex portions 722 are uniformly distributed on the edge of the magnetic conductive body 721. A winding 711 is provided in each of the convex portions 722, and the windings 711 may be provided in the convex portions 722 in which two or more positions are symmetric.

Further, the magnetic permeable unit 72 can also adopt the structure shown in Figs. 7a, 7b, and 7c, the magnetic field generating unit 71 is disposed in the concave portion of the magnetic conductive unit 72, or the magnetic conductive unit 72 is disposed at the end of the winding 711. The end of the winding 711 means the end of the winding 711 in the axial direction. The gas containing magnetic particles flows in the concave portion to form a magnetic eddy current, and the magnetic eddy current can optimize the distribution of magnetic lines of force, thereby improving the anti-interference ability of the chip type magnetic sensor.

Figure 10 is an exploded view of a chip type magnetic sensor according to an eighth embodiment of the present invention. As shown in FIG. 10, the chip type magnetic sensor includes a housing 11, a chip 12, a circuit board 13, an anti-jamming device 14, and a soldering pin 15, and the chip 12, the circuit board 13, and the anti-jamming device 14 are disposed in the housing 11, and are soldered. The pin 15 is electrically connected to the chip 12 through the wiring board 13. The structure of the chip 12, the wiring board 13, the interference preventing device 14 and the welding pin 15 are the same as described above except for the structure and material of the casing 11.

In this embodiment, the housing 11 is made of permalloy, ferrite or steel sheet, or It is made of other metallic or non-metallic materials such as copper and aluminum, and a nickel-iron or permalloy coating is added on the outer surface. A magnetic conductive hole 111 is further disposed on the housing 11. When the chip 12 is placed in the housing 11, the sensing surface of the chip 12 is opposite to the magnetic conductive hole 111, and the external magnetic field including the anti-counterfeiting mark passes through the magnetic conductive. The hole 111 is then sensed by the chip 12.

In this embodiment, the housing 1 ] may be made of a non-shielding material such as copper, iron or plastic, or may be made of a shielding material such as permalloy, ferrite or selenium steel. The housing made of shielding material has good shielding performance, but it also has an adverse effect on the magnetic field of the anti-counterfeiting marking during actual use. For this reason, if the casing 11 is made of an unshielded material, the magnetic flux hole may not be provided in the casing 11. If the casing 11 is made of a shielding material, a magnetic conductive hole 111 is provided in the casing 11.

11a is a perspective view of a chip type magnetic sensor according to Embodiment 9 of the present invention, and FIG. 1b is an exploded view of the chip type magnetic sensor according to Embodiment 9 of the present invention. As shown in Figures 11a and 11b, the chip-type magnetic sensor comprises a housing 11, a chip 12, a circuit board 13, an anti-jamming device 14 and a processing unit (not shown), the chip 12, the anti-jamming device 14 and the processing unit are The circuit board 13 is supported, and a circuit board pad 414 is provided on the circuit board 13, and the circuit board pad 414 is connected to the solder pin 15 for electrically connecting the circuit board 13 and the chip 12. The chip 12 is used to acquire the magnetic change of the object to be measured, and the anti-interference device 14 is used to improve the anti-interference ability and the signal-to-noise ratio of the chip 12, thereby improving the measurement sensitivity of the chip 12.

The housing 11 is provided with a lead-in surface 461, a contact sensing surface 462 and a trailing surface 463. The contact sensing surface 462 is further provided with a magnetic conductive hole 111, and the chip 12 is opposite to the position of the magnetic conductive hole 111. A grounding end 18 for grounding is also provided on the housing 11.

The anti-interference device 14 is an annular structural member, and a magnetic vacuum region can be formed inside the annular structural member. The chip 12 is disposed inside the annular structural member, and the sensing surface of the chip 12 is lower than the upper surface of the annular connecting member.

FIG. 12 is a diagram showing the detection mode of the chip type magnetic sensor according to Embodiment 2 to Embodiment 5 of the present invention. As shown in FIG. 12, in use, the object 50 to be measured slides over the surface of the shell of the chip-type magnetic sensor, and the magnetic conductive unit 72 optimizes the distribution of magnetic lines of force of the magnetic field generating unit 71, and constrains the magnetic lines of force. The two convex portions of the magnetic unit 72 are such that the magnetic lines of force are perpendicular or approximately perpendicular to the convex portion of the magnetic conductive unit 72, and are affected by the magnetic lines of force of the convex portion, and only the magnetic lines perpendicular to the chip 12 can enter the magnetic vacuum region, that is, only the magnetic conductive unit The magnetic field of the magnetic mark 51 opposite to the concave portion of 72 can enter the concave portion, and the magnetic lines of force in other directions are shielded by the magnetic field located at the convex portion. Therefore, only the anti-counterfeit mark 51 which is perpendicular to the chip 12 can be sensed by the chip 12. The chip 2 senses the anti-counterfeit mark 51 in the object to be measured to obtain a differential signal, and the differential signal is transmitted to the processing unit through the circuit board 13. The processing unit discriminates whether or not the magnetic field strength and/or anti-counterfeiting of the anti-counterfeit mark 51 and the anti-counterfeit mark 51 are present according to the differential signal. The size of the logo 51.

The chip type magnetic sensor of the embodiment is provided with an anti-interference device of a magnetic vacuum region, and the chip is placed in a magnetic vacuum region of the anti-interference device, and the sensing surface of the chip faces the anti-counterfeit mark, and only the vertical or near vertical The magnetic lines of force on the sensing surface of the chip can enter the magnetic vacuum region and be sensed by the chip. The magnetic lines in other directions are blocked outside the magnetic vacuum region, so that the electrical signal in the surrounding environment can be effectively suppressed or even eliminated without loss of sensitivity. Or noise such as magnetic signal #u can further improve the signal-to-noise ratio and sensitivity of the magnetic sensor. In addition, the chip is used as a magnetic sensitive component, which is small in size, easy to integrate, and high in sensitivity, thereby reducing the volume of the magnetic sensor, making the magnetic sensor easier to integrate, and improving the sensitivity of the magnetic sensor.

It is to be understood that the above embodiments are merely illustrative embodiments employed to illustrate the principles of the invention, but the invention is not limited thereto. Various modifications and improvements can be made by those skilled in the art without departing from the spirit and scope of the invention. These modifications and improvements are also considered to be within the scope of the invention.

Claims

claims

1. A chip magnetic sensor, including:

A chip used to generate a differential signal based on the sensed magnetic signal of the anti-counterfeiting mark in the object being measured;

A circuit board, the chip is fixed on the circuit board, and the output end of the chip is electrically connected to the wiring provided on the circuit board;

It is characterized in that it also includes an anti-interference device, a magnetic vacuum area is constructed on the anti-interference device, the chip is placed in the magnetic vacuum area, and the sensing surface of the chip faces the measured object.

2. The chip magnetic sensor according to claim 1, wherein the anti-interference device includes a permanent magnet body made of permanent magnet material, and a plurality of the measured objects are constructed on the permanent magnet body. Extending sideways, the magnetic vacuum area is formed between the convex portions.

3. The chip magnetic sensor according to claim 2, wherein the plurality of protrusions are evenly distributed along the circumferential direction of the permanent magnet body.

4. The chip magnetic sensor according to claim 2, wherein the convex portions are continuously distributed along the circumferential direction of the permanent magnet body.

5. The chip magnetic sensor according to claim 4, wherein a plurality of tooth portions are provided on opposite sides of the portion, the plurality of tooth portions are spaced apart, and two adjacent tooth portions are A magnetic vacuum sub-region is formed between them.

6. The chip magnetic sensor according to claim 5, characterized in that a thin film layer is provided on the surface of the part and the tooth part, and the thin film layer is formed of metal, non-metal or gas.

7. The chip magnetic sensor according to claim 2, characterized in that, the core The chip and the circuit board are placed in the magnetic vacuum area between the protrusions.

8. The chip magnetic sensor according to claim 2, wherein the circuit board is provided with a circuit board through hole that matches the convex portion, and the convex portion is formed from a side of the circuit board. One side passes through the through hole of the circuit board and extends from the other side of the circuit board. The top end of the convex portion is flush with or higher than the sensing surface of the chip.

9. The chip magnetic sensor according to claim 1, wherein the anti-interference device includes a permanent magnet body made of permanent magnet material, and a permanent magnet body through hole is provided in the permanent magnet body. A magnetic vacuum area is formed in the through hole of the permanent magnet body. One end of the through hole of the permanent magnet body is opposite to the object to be measured. The chip and the circuit board are placed on the permanent magnet body. surface.

10. The chip magnetic sensor according to any one of claims 2 to 9, characterized in that the permanent magnet body is made of ferrite, permalloy or silicon steel sheet; or, the permanent magnet body is made of It is made of neodymium iron boron, samarium cobalt or alnico, or made of metal materials or non-metal materials, with a nickel iron or permalloy coating added to its outer surface.

11. The chip magnetic sensor according to claim 1, wherein the anti-interference device includes a winding and a power supply, the power supply provides electrical energy to the winding, and the magnetic vacuum area is formed inside the winding. , the end of the winding is opposite to the object under test.

12. The chip magnetic sensor according to claim 1, wherein the anti-interference device includes a magnetic field generating unit and a magnetic permeable unit, the magnetic field generating unit is used to generate a magnetic vacuum area formed in the magnetic permeable unit. Inside.

13. The chip magnetic sensor according to claim 12, wherein the magnetic conductive unit includes a magnetic conductive body made of magnetic conductive material, and a plurality of protrusions are provided on the magnetic conductive body. The measured object side extends, and the magnetic vacuum area is formed between the convex portions.

14. The chip magnetic sensor according to claim 13, characterized in that two oppositely arranged protrusions are constructed on the magnetic conductive body, and the chip is placed between the two protrusions.

15. The chip magnetic sensor according to claim 13, wherein the convex portions are continuously distributed along the circumferential direction of the magnetic conductive body.

16. The chip magnetic sensor according to claim 13, wherein the chip and the circuit board are placed between the convex parts.

17. The chip magnetic sensor according to claim 13, characterized in that, the circuit board is provided with a circuit board through hole matching the convex portion, and the convex portion of the magnetic conductive unit is formed from the said convex portion. One side of the circuit board passes through the circuit board through hole and extends from the other side of the circuit board. The top of the convex portion is flush with or higher than the sensing surface of the chip. .

18. The chip magnetic sensor according to claim 12, wherein the magnetic conductive unit includes a magnetic conductive body made of magnetic conductive material, and a magnetic conductive body through hole is provided in the magnetic conductive body, A magnetic vacuum area is formed in the through hole of the magnetic conductive body, one end of the through hole of the magnetic conductive body is opposite to the object to be measured, and the chip and the circuit board are placed on the surface of the through hole body.

19. The chip magnetic sensor according to claim 12, characterized in that the magnetic field generating unit is a permanent magnet made of ferrite, permalloy or silicon steel sheet.

20. The chip magnetic sensor according to claim 12, wherein the magnetic field generating unit includes a winding and a power supply, and the power supply provides electrical energy to the winding; and the magnetic permeability unit is provided inside the winding. or the end of said winding.

21. The chip magnetic sensor according to claim 1, wherein the magnetic vacuum area is filled with gas containing magnetic particles, and the gas containing magnetic particles flows in the magnetic vacuum area to form a magnetic field. vortex.

22. The chip magnetic sensor according to claim 1, wherein the chip includes at least a pair of magnetically sensitive films and a chip pad electrically connected to the magnetically sensitive films, and the at least one Wheatstone electrically conductive bridge circuit,

23. The chip magnetic sensor according to claim 22, characterized in that _n suppression units for segmentally suppressing the demagnetization field of the magnetically sensitive film are provided in the length direction of the magnetically sensitive film, so The suppression units are spaced on the surface of the magnetically sensitive film and n is an integer > 2.

24. The chip magnetic sensor according to claim 23, wherein the suppression unit is made of conductive material.

25. The chip magnetic sensor according to claim 22, wherein the magnetically sensitive film is a Hall effect film, an anisotropic magnetoresistance film, a giant magnetoresistance film, a tunnel magnetoresistance film, or a giant magnetoresistance film. Or giant Hall effect film.

26. The chip magnetic sensor according to claim 1, characterized in that it includes a housing, a processing unit and a welding pin, wherein,

The processing unit is configured to identify the anti-counterfeiting mark according to the differential signal;

The chip and the circuit board are located in the housing; the processing unit is located in the housing or outside the housing;

The soldering pins are electrically connected to the wiring on the circuit board, and the soldering pins are used for signal transmission and supporting the housing.

27. The chip magnetic sensor according to claim 26, characterized in that: The circuit board is a hard resin material matrix circuit board or a flexible base shield circuit board.

28. The chip magnetic sensor according to claim 26, wherein the housing is provided with a magnetic hole, and the chip is opposite to the magnetic hole.

29. The chip magnetic sensor according to claim 26, characterized in that the housing is made of copper, iron or plastic.

30. The chip magnetic sensor according to claim 26, characterized in that the housing is made of permalloy, ferrite or single steel sheet; or, it is made of metallic material or non-metallic material, and is made of The outer surface is provided with a nickel-iron or permalloy coating.