CN103971444A - Magnetic sensor for magnetic detection - Google Patents
Magnetic sensor for magnetic detection Download PDFInfo
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- CN103971444A CN103971444A CN201310034302.6A CN201310034302A CN103971444A CN 103971444 A CN103971444 A CN 103971444A CN 201310034302 A CN201310034302 A CN 201310034302A CN 103971444 A CN103971444 A CN 103971444A
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Abstract
The invention provides a magnetic sensor for magnetic detection. The magnetic sensor comprises a chip and a flux-weakening reinforcement unit. The chip is used for inducting a magnetic anti-fake mark in a medium to be detected. The flux-weakening reinforcement unit is used for carrying out pre-magnetization on the magnetic anti-fake mark so that the chip can induct the magnetic anti-fake mark sensitively. The magnetic sensor for magnetic detection is particularly suitable for detection and identification of the flux-weakening mark, capable of identifying the flux-weakening anti-fake mark, high in capacity of resisting disturbance, small in size, easy to integrate and high in sensitivity.
Description
Technical field
The invention belongs to microelectronics technology, be specifically related to a kind of Magnetic Sensor that can respond to detection magnetic anti-counterfeiting mark, particularly detect weak magnetic anti-counterfeiting mark.
Background technology
The variation of electric current, ess-strain, temperature and light etc. can produce magnetic field, and magnetic field can cause that the magnetic property of magneto sensor changes.Convert the variation of the magnetic property of magneto sensor to electric signal, measure this electric signal and can know whether tested region exists electric current, ess-strain, temperature or the light etc. that can produce magnetic field.Magnetic Sensor is the measurement mechanism that utilizes these characteristics of magneto sensor to grow up, and is widely used in finance, Aeronautics and Astronautics, microelectronics, the fields such as geological exploration, medical imaging, information acquisition and military affairs.
At industrial circle, most widely used Magnetic Sensor is coil type Magnetic Sensor, taking coil as magneto sensor.Fig. 1 is the structural drawing of the Magnetic Sensor of current financial field employing.As shown in Figure 1, Magnetic Sensor comprises shell 101, coil 109 and printed circuit board 113, is provided with an opening 103 on shell 101 tops.Be provided with a narrow and small magnetic gap 107 at the middle position on magnetic core 105a, 105b top, magnetic core 105a, 105b are fixed in shell 101 by support 111, and stretch out from the opening 103 of shell 101 on its top.Bottom at magnetic core 105a, 105b is wound with multiturn coil, and coil 109 is connected with printed circuit board 113, and printed circuit board 113 is connected with other parts of being located at screening can 101 outsides by capillary 114a, 114b.Magnetic core 105a, 105b and coil 109 form antenna assembly, and it is easy to accept electric signal and the magnetic signal in external environment.In the time of currency examine, banknote magnetic oil ink-stick or magnetic metal bar streak from the top of magnetic core 105a, 105b, magnetic gap 107 makes the induced electromotive force corresponding with banknote magnetic oil ink-stick or magnetic metal bar magnetic field intensity ratio in the interior generation of coil 109, can distinguish the true and false of banknote according to this induced electromotive force.
Along with the variation of the market demand, Magnetic Sensor is gradually to miniaturization and integrated development.Coil type Magnetic Sensor volume is large, Heavy Weight, and low-response, resolution is low, sensitivity is low, reliability and poor anti jamming capability.The more important thing is, along with the raising of financial anti-counterfeit capability, the weak magnetic mark of the more employings of anti-counterfeiting mark, this has increased the difficulty of imitative puppet greatly, also increased the difficulty of false distinguishing simultaneously, not only require high sensitivity and reliability, and requirement can be implemented, and multiple spot detects, seamless detection and expansion are subject to inspection scope, existing Magnetic Sensor cannot meet market the demand to Magnetic Sensor.Therefore, be badly in need of exploitation a kind of miniaturization, easy of integration, highly sensitive, and can identify the Magnetic Sensor of weak magnetic mark.
Summary of the invention
The technical problem to be solved in the present invention is exactly for the above-mentioned defect existing in Magnetic Sensor, provides a kind of magnetic to detect Magnetic Sensor, and its volume is little, easy of integration, highly sensitive, and can be used in the weak magnetic mark of detection.
For this reason, the invention provides a kind of magnetic and detect Magnetic Sensor, comprising:
Chip, for responding to the magnetic anti-counterfeiting mark detecting in medium to be detected;
Weak magnetic strength unit, for described magnetic anti-counterfeiting mark is carried out to premagnetization, detects described magnetic anti-counterfeiting mark so that described chip can be responded to.
Wherein, on described weak magnetic strength unit, be provided with spatial accommodation, the openend of described spatial accommodation is towards described medium to be detected, and described chip is arranged at described spatial accommodation, and the sensitive surface of described chip is towards described medium to be detected.
Wherein, described weak magnetic strength unit comprises:
Permanent magnet, for generation of the magnetic field of magnetic mark described in premagnetization;
Magnetic conductor, described magnetic conductor is stacked and placed on described permanent magnet, and described magnetic conductor comprises the magnetic conduction arm that at least one extends towards described medium to be detected, and described spatial accommodation arranges near described magnetic conduction arm.
Wherein, described magnetic conductor comprises two magnetic conduction arms that extend towards described medium to be detected, and described spatial accommodation is arranged between two described magnetic conduction arms.
Wherein, described magnetic conduction arm is perpendicular to the detection faces of described medium to be detected, so that the magnetic direction that described permanent magnet produces is perpendicular to the detection faces of described medium to be detected.
Wherein, described permanent magnet adopts neodymium iron boron, SmCo, and aluminium nickel cobalt, ferrite, permalloy, or silicon steel sheet is made.
Wherein, described spatial accommodation is blind hole or the through hole being arranged on described magnetic conductor.
Wherein, described weak magnetic strength unit comprises:
Winding, for generation of the magnetic field of magnetic anti-counterfeiting mark described in premagnetization;
Power supply, for providing electric energy to described winding;
Magnetic conductor, makes the magnetic field of described winding generation perpendicular to the sensitive surface of described chip.
Wherein, described magnetic conductor comprises magnetic conduction body and at least two magnetic conduction arms, and described magnetic conduction arm is symmetrical arranged along the periphery of described magnetic conduction body;
Described chip is arranged between described magnetic conduction arm, and the sensitive surface of described chip is towards described medium to be detected;
Winding described in magnetic conduction arm correspondence one described in each, described in each, winding is placed on the outside of magnetic conduction arm described in accordingly.
Wherein, described magnetic conductor comprises magnetic conduction body and two magnetic conduction arms, and two described magnetic conduction arms are relatively arranged at the both sides of described magnetic conduction body.
Wherein, described magnetic conductor comprises magnetic conduction body and the support portion of being located at described magnetic conduction body end, and described winding is placed on the outside of described magnetic conduction body;
Described chip is arranged at described support portion.
Wherein, the pad that described chip comprises at least one pair of magnetic sensitive film and is electrically connected with described magnetic sensitive film, is linked to be wheatstone bridge circuits by described pad and wire by described magnetic sensitive film.
Wherein, every described magnetic sensitive film is continuous continual magnetic sensitive film; Or,
Every described magnetic sensitive film comprises multistage magnetic sensitive film section and connects the conductor of described magnetic sensitive film section.
Wherein, on the length direction of described magnetic sensitive film, be provided with the inhibition unit that n segmentation suppresses the demagnetizing field of described magnetic sensitive film, described inhibition unit interval is arranged at the surperficial and/or inner of described magnetic sensitive film, wherein, and the integer that n is >=2.
Wherein, described inhibition unit is otch, electric conductor, calandria, insulator or hard magnetic body.
Wherein, the magnetic line of force direction of described weak magnetic strength unit is vertical with the pinning direction of described magnetic sensitive film.
Wherein, described magnetic sensitive film is Hall effect film, anisotropic magnetoresistance film, giant magnet resistance film, tunnel magneto resistance film, giant magnetoresistance films or giant Hall effect film.
Wherein, comprise housing, wiring board, processing unit and capillary, wherein,
Described wiring board is electrically connected with described chip, the differential signal obtaining for delivery of described chip;
Described processing unit is for distinguishing described anti-counterfeiting mark according to described differential voltage signal;
Described chip and described wiring board are located in described housing; Described processing unit is located in described housing or is located at outside described housing;
Described capillary is electrically connected with described wiring board, and described capillary is used for the transmission of signal and supports described housing.
Wherein, on described housing, be provided with magnetic conductive hole, described chip is relative with described magnetic conductive hole.
Wherein, described housing adopts copper, aluminium or its oxide or plastic production.
Wherein, described housing adopts permalloy, ferrite or selenium steel disc to make; Or, adopt metal material or nonmetallic materials to make, and at its outside surface plating chromium, the coating of ferronickel or permalloy.
The present invention has following beneficial effect:
Magnetic provided by the invention detects Magnetic Sensor and comprises weak magnetic strength unit, in the time detecting medium to be detected, magnetic field-intensification unit produces the magnetic field perpendicular to the detection faces of medium to be detected, make weak magnetic anti-counterfeiting mark premagnetization, weak magnetic anti-counterfeiting mark after premagnetization can produce magnetic field, the magnetic field that the weak magnetic anti-counterfeiting mark of chip induction produces also obtains differential output signal, the amplitude of this differential output signal and waveform and weak magnetic anti-counterfeiting mark are corresponding relation, can differentiate the true and false of medium to be detected according to the amplitude of this differential output signal and waveform.In addition, weak magnetic strength unit has good antijamming capability, thereby can improve the reliability of weak magnetic detection Magnetic Sensor.
Brief description of the drawings
Fig. 1 is the structural drawing of the Magnetic Sensor of current financial field employing;
Fig. 2 a is the structural drawing that embodiment of the present invention magnetic detects Magnetic Sensor;
Fig. 2 b is the exploded view that embodiment of the present invention magnetic detects Magnetic Sensor;
Fig. 2 c is the partial schematic diagram that embodiment of the present invention magnetic detects Magnetic Sensor;
Fig. 2 d is the partial schematic diagram that another magnetic of the embodiment of the present invention detects Magnetic Sensor;
Fig. 3 is that embodiment of the present invention magnetic detects Magnetic Sensor use constitutional diagram;
Fig. 4 a is the structural drawing of the invention process spr chip;
Fig. 4 b is the part-structure figure of another chip of the embodiment of the present invention;
Fig. 4 c is the part-structure figure of the another chip of the embodiment of the present invention;
Fig. 5 a is the exploded view that another embodiment of the present invention magnetic detects Magnetic Sensor;
Fig. 5 b is the part-structure figure that another magnetic of the embodiment of the present invention detects Magnetic Sensor;
Fig. 6 is the part-structure schematic diagram that embodiment of the present invention magnetic detects Magnetic Sensor;
Fig. 7 a is the sectional view that further embodiment of this invention magnetic detects Magnetic Sensor;
Fig. 7 b is the sectional view that another magnetic of the embodiment of the present invention detects Magnetic Sensor;
Fig. 8 a is the exploded view that yet another embodiment of the invention magnetic detects Magnetic Sensor
Fig. 8 b is the sectional view that another magnetic of the embodiment of the present invention detects Magnetic Sensor;
Fig. 8 c is the sectional view that the another magnetic of the embodiment of the present invention detects Magnetic Sensor.
Embodiment
For making those skilled in the art understand better technical scheme of the present invention, below in conjunction with accompanying drawing, magnetic provided by the invention is detected to Magnetic Sensor and be described in detail.
Fig. 2 a is the structural drawing that embodiment of the present invention magnetic detects Magnetic Sensor, and Fig. 2 b is the exploded view that embodiment of the present invention magnetic detects Magnetic Sensor.As shown in Figure 2 a and 2 b, magnetic detection Magnetic Sensor comprises housing 11, chip 12, wiring board 13, weak magnetic strength unit 14, processing unit (not shown) and capillary 15.Wherein, chip 12 is for responding to the anti-counterfeiting mark in medium to be detected and obtaining differential signal, and anti-counterfeiting mark comprises weak magnetic anti-counterfeiting mark and/or strong magnetic anti-counterfeiting mark.Wherein, strong magnetic anti-counterfeiting mark itself can produce magnetic field, and that weak magnetic anti-counterfeiting mark itself does not produce the magnetic field of magnetic field or generation is very weak.Therefore,, if will be detected weak magnetic anti-counterfeiting mark by chip 12, first need weak magnetic anti-counterfeiting mark to carry out premagnetization, so that the magnetic field that its generation can be responded to by chip 12.Weak magnetic strength unit 14 can carry out premagnetization to weak magnetic anti-counterfeiting mark, and makes weak magnetic anti-counterfeiting mark the short time produce magnetic field, and chip 12 inductions detect by the magnetic field of the weak magnetic anti-counterfeiting mark of premagnetization.
Chip 12, wiring board 13 and weak magnetic strength unit 14 are located in housing 11.Chip 12 is electrically connected with capillary 15 by wiring board 13.Processing unit is for distinguishing described anti-counterfeiting mark according to described differential voltage signal, it can be located in housing 11, also can be located at outside housing 11, it distinguishes the true and false, size or the power of anti-counterfeiting mark for the differential signal of exporting according to chip 12, thereby distinguishes the true and false of medium to be detected.
The present embodiment wiring board 13 adopts hard wiring board, and chip 12 is fixed on hard wiring board, and the signal output part of chip 12 is electrically connected with the conducting wire of being located on hard wiring board, and is electrically connected with capillary 15 by the conducting wire on hard wiring board.If processing unit is located at housing 11 when interior, the result that capillary 15 obtains for transmission processing unit; If processing unit is located at housing 11 when outer, the differential signal that capillary 15 obtains for transmitting chip 12.Capillary 15 can also be used for support housing 11.
Certainly, wiring board 13 can also adopt flexible circuit board, as long as can, by the differential signal output of chip 12, can reach equally object of the present invention.
Fig. 2 c is the partial schematic diagram that embodiment of the present invention magnetic detects Magnetic Sensor.As shown in Fig. 2 b and Fig. 2 c, weak magnetic strength unit 14 comprises permanent magnet 141 and magnetic conductor 142.Permanent magnet 141 is for generation of the magnetic field of magnetic mark a little less than premagnetization, it adopts the rare earth permanent-magnetic materials such as neodymium iron boron, SmCo or aluminium nickel cobalt to make, or adopt the permanent magnetic materials such as ferrite sintered body, bonded ferrite or injecting ferrite to make, or adopt permalloy or silicon steel sheet to make.On magnetic conductor 142, be provided with two magnetic conduction arms 144 that are oppositely arranged, magnetic conduction arm 144, to intermediary parties to be detected to extension, has formed the spatial accommodation for holding chip 12 between two magnetic conduction arms 144.Chip 12 and wiring board 13 are located in spatial accommodation 143, and the sensitive surface of chip 12 is lower than the upper surface of magnetic conductor 142, and the sensitive surface of chip 12 is lower than the top of magnetic conduction arm 144, thereby chip 12 and wiring board 13 are embedded to spatial accommodation 143.Magnetic conductor 142 is stacked with permanent magnet 141, and magnetic conductor 142 is positioned near medium one side to be detected, and the magnetic conduction arm 144 of magnetic conductor 142 is towards medium to be detected, thereby makes the opening of spatial accommodation 143 towards medium to be detected.
The magnetic permeability of magnetic conductor 142 is very high, can make the magnetic line of force in the magnetic field of permanent magnet 141 transmit along its matrix, by matrix along two relative magnetic conduction arms 144 to media transmission to be detected, thereby magnetize medium to be detected and make it and there is magnetic field, so on the one hand medium to be detected is magnetized, make on the other hand the spatial accommodation 143 between its two relative magnetic conduction arm 144 form magnetic vacuum region, can reduce the interference of extraneous other magnetic field to chip 12, thereby can effectively suppress, even eliminate the noise such as electric signal or magnetic signal in surrounding environment, and then signal to noise ratio (S/N ratio) and the sensitivity that can improve Magnetic Sensor.
Preferably, magnetic conduction arm 144 is perpendicular to the detection faces of medium to be detected, thereby makes magnetic direction that permanent magnet 142 the produces detection faces perpendicular to medium to be detected, is so more conducive to the weak magnetic anti-counterfeiting mark of premagnetization.
Comprise two magnetic conduction arms 144 although disclosed magnetic conductor 141 above, the present embodiment magnetic conductor 141 can only arrange a magnetic conduction arm 144, arranges near magnetic conduction arm 144 for the spatial accommodation 143 of chip placement 12.When use, make magnetic conduction arm 144 first slip over anti-counterfeiting mark, make weak magnetic anti-counterfeiting mark premagnetization, then chip 12 slips over from anti-counterfeiting mark, detects the magnetic field of weak magnetic anti-counterfeiting mark.Certainly, magnetic conductor 141 also can arrange three or more magnetic conduction arms 144, as long as the spatial accommodation 143 that chip 12 is set is arranged near magnetic conduction arm 144.
As shown in Figure 2 b, be also provided with earth terminal 18 on housing 11, housing 11 is by earth terminal 18 ground connection.Housing 11 adopts the nonmagnetic substances such as copper, aluminium and oxide thereof to make, or adopts plastic production.
Fig. 2 d shows the partial schematic diagram of another magnetic detection Magnetic Sensor of the embodiment of the present invention, as shown in Figure 2 d, the outside peripheral dimension of magnetic conductor 142 equates with the outside peripheral dimension of permanent magnet 141, make the magnetic line of force of magnetic conductor 142 mainly concentrate on permanent magnet 141 under, to reduce the magnetic field intensity of permanent magnet 141 peripheries.Certainly the outside peripheral dimension that, the outside peripheral dimension of magnetic conductor 142 is less than permanent magnet 141 equally can 141 peripheries magnetic field intensity.The magnetic field of magnetic conductor 142 is constrained in its magnetic conduction arm 144 as much as possible by permanent magnet 141 like this, strengthen the magnetic field intensity of magnetic conduction arm 144 positions, both be conducive to the weak magnetic anti-counterfeiting mark of premagnetization, can reduce again the impact in extraneous other magnetic field (magnetic field except anti-counterfeiting mark), thereby improve the sensitivity of magnetic detection Magnetic Sensor.Therefore, in actual applications, preferably the outside peripheral dimension of magnetic conductor 142 is less than or equal to the chip type Magnetic Sensor of the outside peripheral dimension of permanent magnet 141.
Fig. 3 is that embodiment of the present invention magnetic detects Magnetic Sensor use constitutional diagram.Medium to be detected is banknote 50, is provided with strong magnetic anti-counterfeiting mark and weak magnetic anti-counterfeiting mark in banknote 50.As shown in Figure 3, because chip 12 is arranged on recess 143, magnetic conduction arm 144 makes the magnetic field B of permanent magnet 141 assemble to the front-end and back-end at chip 12 (left and right sides).In the time that magnetic detection Magnetic Sensor 40 streaks from banknote 50 surfaces, or, in the time that banknote 50 streaks from the surface of magnetic detection Magnetic Sensor 40, weak magnetic anti-counterfeiting mark is first by the magnetic field B premagnetization of permanent magnet 141, produced by the weak magnetic anti-counterfeiting mark after premagnetization the magnetic field that can be responded to by chip 12, chip 12 is responded to the magnetic field of weak magnetic anti-counterfeiting mark and is obtained differential output signal, the amplitude of this differential output signal and waveform and weak magnetic anti-counterfeiting mark are corresponding relation, can differentiate the true and false of banknote 50 according to the amplitude of this differential output signal and waveform.
Fig. 4 a is the structural drawing of the invention process spr chip.As shown in Fig. 4 a, chip 12 comprises supporter 121, a pair of magnetic sensitive film 122 and pad 123, and magnetic sensitive film 122 and pad 123 are located at the surface of supporter 121.Pad 123 is electrically connected with magnetic sensitive film 122, and pad 123 is for magnetic sensitive film 122 and being electrically connected such as wiring board 13 circuits such as grade.Chip 12 volumes that are made up of magnetic sensitive film are little, easy of integration, and highly sensitive.
Particularly, chip 12 comprises two continuous continual magnetic sensitive film 122a, 122b and three pad 123a, 123b, 123c, the first pad 123a is located at the head end of the first magnetic sensitive film 122a, the second pad 123b is located at the tail end of the first magnetic sensitive film 122a and the tail end of the second magnetic sensitive film 122b, and the 3rd pad 123c is located at the head end of the second magnetic sensitive film 122b.Utilize wiring board 13 and pad 123a, 123b, 123c magnetic sensitive film 122a, 122b can be connected into Hui Sitong half-bridge circuit.Chip 12 is subject to magnetic field induction can produce differential output signal.Preferably, the magnetic line of force trend of weak magnetic strength unit 14 is vertical with the pinning direction of magnetic sensitive film 122a, 122b, to avoid the impact of weak magnetic strength unit 14 on chip 12.
In the present embodiment, chip 12 also can comprise three or four or more magnetic sensitive films, that is to say, chip 12 should comprise at least one pair of magnetic sensitive film, and magnetic sensitive film is electrically connected and is connected into Hui Sitong half-bridge circuit or Hui Sitong full-bridge circuit.Magnetic sensitive film 122 is Hall effect film, anisotropic magnetoresistance film, giant magnet resistance film, tunnel magneto resistance film, giant magnetoresistance films or giant Hall effect film.
In addition, the present embodiment magnetic sensitive film both can adopt continuous continual magnetic sensitive film, can adopt again discontinuous magnetic sensitive film.As shown in Figure 4 b, magnetic sensitive film 122 comprises multistage magnetic sensitive film section 125, and magnetic sensitive film section 125 is electrically connected by conductor 126.
Fig. 4 c is the part-structure figure of the another chip of the embodiment of the present invention.As shown in Fig. 4 c, on the length direction of magnetic sensitive film 12, be provided with n inhibition unit 127 that suppresses the demagnetizing field of magnetic sensitive film 122 for segmentation, suppress unit 127 and be arranged at intervals at the surperficial and/or inner of magnetic sensitive film 122, wherein, the integer that n is >=2.Suppressing unit 127 can be otch, electric conductor, calandria, insulator or hard magnetic body.
Fig. 5 a is the exploded view that another embodiment of the present invention magnetic detects Magnetic Sensor, and Fig. 5 b is the part-structure figure that another magnetic of the embodiment of the present invention detects Magnetic Sensor.As shown in Figure 5 a, magnetic detection Magnetic Sensor comprises housing 11, chip 12, wiring board 13, weak magnetic strength unit 14, processing unit (not shown) and capillary 15.Wherein, the structure of housing 11, chip 12, wiring board 13, processing unit and capillary 15 is same as the previously described embodiments, does not repeat them here.The difference of the present embodiment and above-described embodiment is the structure of weak magnetic strength unit 14.
As shown in Figure 5 b, weak magnetic strength unit 14 comprises permanent magnet 141 and magnetic conductor 142, and magnetic conductor 142 is stacked and placed on permanent magnet 142.Permanent magnet 141 is for generation of the magnetic field of magnetic mark a little less than premagnetization, it adopts the rare earth permanent-magnetic materials such as neodymium iron boron, SmCo or aluminium nickel cobalt to make, or adopt the permanent magnetic materials such as ferrite sintered body, bonded ferrite or injecting ferrite to make, or adopt permalloy or silicon steel sheet to make.On magnetic conductor 142, be provided with through hole 145, make magnetic conductor 142 form the magnetic conductor of ring texture.Spatial accommodation is formed at through hole 145, and chip 12 and wiring board 13 are placed in through hole 145.The effect of the magnetic conductor 142 of ring texture is similar to magnetic conduction arm, the magnetic permeability of magnetic conductor 142 is very high, can make the magnetic line of force in the magnetic field of permanent magnet 141 transmit along its matrix, by matrix along to media transmission to be detected, thereby magnetize medium to be detected and make it and there is magnetic field, so on the one hand medium to be detected is magnetized; On the other hand in the interior magnetic vacuum region that formed of through hole 145, thereby can reduce the interference of extraneous other magnetic field to Magnetic Sensor, effectively suppress, even eliminate the noise such as electric signal or magnetic signal in surrounding environment and then signal to noise ratio (S/N ratio) and the sensitivity that can improve Magnetic Sensor.
It should be noted that, the through hole 145 being arranged on magnetic conductor 142 also can replace by blind hole,, on magnetic conductor 142, pit is being set that is, can reach equally object of the present invention.
Fig. 6 is the part-structure schematic diagram that embodiment of the present invention magnetic detects Magnetic Sensor.As shown in Figure 6, the key distinction of the present embodiment and previous embodiment is: weak magnetic strength unit 14 is arranged between two magnetic sensitive films 122 of chip 12.In Fig. 6, arrow represents the pinning direction of magnetic sensitive film 122.Preferably, the trend of the magnetic line of force of weak magnetic strength unit 14 is vertical with the pinning direction of magnetic sensitive film 122, to avoid the impact of weak magnetic strength unit 14 on chip 12 (if out of plumb, chip 12 is easy to be subject to the impact of weak magnetic strength unit 14 and saturated).In the present embodiment, weak magnetic strength unit 14 can be the parts that permanent magnet or coil etc. can produce magnetic field.The modes of emplacement of weak magnetic strength unit 14 can be any, as the N utmost point of weak magnetic strength unit 14 being located near medium one side to be detected, or the S utmost point of weak magnetic strength unit 14 is located near medium one side to be detected.
Fig. 7 a is the sectional view that further embodiment of this invention magnetic detects Magnetic Sensor.As shown in Figure 7a, magnetic detection Magnetic Sensor comprises housing 11, chip 12, wiring board 13, weak magnetic strength unit 14, processing unit (not shown) and capillary 15.Except weak magnetic strength unit 14, other structure of magnetic detection Magnetic Sensor is same as the previously described embodiments, does not repeat them here.
Weak magnetic strength unit 14 comprises magnetic conductor 142, winding 147 and power supply (not shown), and wherein, power supply provides electric energy for winding 147, and winding 147 is for generation of magnetic field.Magnetic conductor 142 comprises that magnetic conduction body 41 and 42, two magnetic conduction arms 42 of two magnetic conduction arms are relatively arranged at the both sides of magnetic conduction body 41.The corresponding winding 147 of each magnetic conduction arm 42, winding 147 is placed on the outside of magnetic conduction arm 42.The magnetic field S that magnetic conductor 142 produces winding 147 is gathered in magnetic conduction arm 42, and forms magnetic vacuum region in spatial accommodation between magnetic conduction arm 42.Chip 12 and wiring board 13 are located at spatial accommodation, and the sensitive surface of chip 12 is towards medium to be detected.The magnetic field of winding 147 is by magnetic conduction arm 42, on the one hand premagnetization weak magnetic anti-counterfeiting mark; Form magnetic vacuum region at spatial accommodation on the other hand, can reduce the interference of extraneous other magnetic field to Magnetic Sensor, thereby effectively suppress, even eliminate the noise such as electric signal or magnetic signal in surrounding environment and then signal to noise ratio (S/N ratio) and the sensitivity that can improve Magnetic Sensor.Preferably, make magnetic field that winding 147 the produces sensitive surface perpendicular to chip 12, be so more conducive to the premagnetization of weak magnetic anti-counterfeiting mark, and improve the magnetic vacuum of spatial accommodation.
Multiple magnetic conduction arms 42 can also be set on magnetic conduction body 41, and multiple magnetic conduction arms 42 are symmetrical arranged along the periphery of magnetic conduction body 41.The corresponding winding 147 of each magnetic conduction arm 42, each winding 147 is placed on the outside of a magnetic conduction arm 42 accordingly.When use, chip 12 is arranged to spatial accommodation, and the sensitive surface of chip 12 is towards medium to be detected, can reduce equally the interference of extraneous other magnetic field to Magnetic Sensor, thereby effectively suppress, even eliminate the noise such as electric signal or magnetic signal in surrounding environment and then signal to noise ratio (S/N ratio) and the sensitivity that can improve Magnetic Sensor.
Fig. 7 b is the sectional view that further embodiment of this invention magnetic detects Magnetic Sensor.As shown in Figure 7b, weak magnetic detection Magnetic Sensor comprises housing 11, chip 12, wiring board 13, weak magnetic strength unit 14, processing unit (not shown) and capillary 15.The present embodiment is except weak magnetic strength unit 14, and other structure of weak magnetic detection Magnetic Sensor is same as the previously described embodiments, does not repeat them here.
Weak magnetic strength unit 14 comprises magnetic conductor 142, winding 147 and power supply (not shown), and wherein, power supply provides electric energy for winding 147, and winding 147 is for generation of magnetic field.Magnetic conductor 142 comprises magnetic conduction body 61 and the support portion 62 of being located at magnetic conduction body 61 ends, and magnetic conduction body 61 and support portion 62 form " work " character form structure, and winding 147 is nested with (around the home) in the outside of magnetic conduction body 61.The weak magnetic strength of the present embodiment unit 14 does not form spatial accommodation, and chip 12 is located at support portion 62.Particularly, chip 12 is arranged at the surface of wiring board 13, and wiring board 13 is arranged at the surface of support portion 62, and the magnetic field B that winding 147 produces is perpendicular to the sensitive surface of chip 12.
In the present embodiment, housing 11 can also adopt screening can, and housing 11 adopts permalloy, ferrite or selenium steel disc to make; Or, adopt metal material or nonmetallic materials to make, and at the coating of its outside surface plating ferronickel or permalloy.
Fig. 8 a is the exploded view that yet another embodiment of the invention magnetic detects Magnetic Sensor.As shown in Figure 8 a, magnetic detection Magnetic Sensor comprises housing 11, chip 12, wiring board 13, weak magnetic strength unit 14, processing unit (not shown) and capillary 15.
In the present embodiment, be provided with magnetic conductive hole 71 on housing 11, chip 12, wiring board 13, weak magnetic strength unit 14 are located in housing 11, and chip 12 is relative with magnetic conductive hole 71.The magnetic field of anti-counterfeiting mark enters in housing 11 by magnetic conductive hole 71 and is responded to by chip 12.Other structure of the present embodiment can adopt the arbitrary structures of above-described embodiment.
Fig. 8 b is the sectional view that another magnetic of the embodiment of the present invention detects Magnetic Sensor.As shown in Figure 8 b, be provided with magnetic conductive hole 71 on housing 11, chip 12, wiring board 13, weak magnetic strength unit 14 are located in housing 11.Chip 12 is fixed on wiring board 13, and chip 12 and wiring board 13 are located in the spatial accommodation of weak magnetic strength unit 14, and chip 12 is relative with magnetic conductive hole 71.
Fig. 8 c is the sectional view that the another magnetic of the embodiment of the present invention detects Magnetic Sensor.As shown in Figure 8 c, be provided with magnetic conductive hole 71 on housing 11, chip 12, wiring board 13, weak magnetic strength unit 14 are located in housing 11.Wiring board 13 is fixed on the support portion 62 of weak magnetic strength unit 14, and chip 12 is fixed on wiring board 13, and chip 12 is relative with magnetic conductive hole 71.
It should be noted that; different structure and the use-pattern of housing 11, chip 12, wiring board 13 and weak magnetic strength unit 14 in above-described embodiment, are introduced respectively; in actual use, the combination in any of the different structure of housing 11, chip 12, wiring board 13 and weak magnetic strength unit 14 belongs to protection scope of the present invention equally.
The magnetic that the present embodiment provides detects Magnetic Sensor and comprises weak magnetic strength unit, in the time detecting medium to be detected, magnetic field-intensification unit produces the magnetic field perpendicular to the detection faces of medium to be detected, with to magnetic anti-counterfeiting mark, especially weak magnetic anti-counterfeiting mark is carried out to premagnetization, weak magnetic anti-counterfeiting mark after premagnetization can produce magnetic field, in the time that magnetic core passes through, Wheatstone bridge in chip is responded to the weak magnetic anti-counterfeiting mark being magnetized, and produce differential output signal, weak magnetic anti-counterfeiting mark in the amplitude of this differential output signal and waveform and medium to be detected is corresponding relation, just can differentiate the true and false of medium to be detected according to the amplitude of this differential output signal and waveform.In addition, weak magnetic strength unit has good antijamming capability, thereby can improve the reliability of magnetic detection Magnetic Sensor.
Be understandable that, above embodiment is only used to principle of the present invention is described and the illustrative embodiments that adopts, but the present invention is not limited thereto.For those skilled in the art, without departing from the spirit and substance in the present invention, can make various modification and improvement, these modification and improvement are also considered as protection scope of the present invention.
Claims (21)
1. magnetic detects a Magnetic Sensor, comprising:
Chip, for responding to the magnetic anti-counterfeiting mark detecting in medium to be detected;
It is characterized in that,
Also comprise weak magnetic strength unit, for described magnetic anti-counterfeiting mark is carried out to premagnetization, detect described magnetic anti-counterfeiting mark so that described chip can be responded to.
2. magnetic according to claim 1 detects Magnetic Sensor, it is characterized in that, on described weak magnetic strength unit, be provided with spatial accommodation, the openend of described spatial accommodation is towards described medium to be detected, described chip is arranged at described spatial accommodation, and the sensitive surface of described chip is towards described medium to be detected.
3. magnetic according to claim 2 detects Magnetic Sensor, it is characterized in that, described weak magnetic strength unit comprises:
Permanent magnet, for generation of the magnetic field of magnetic mark described in premagnetization;
Magnetic conductor, described magnetic conductor is stacked and placed on described permanent magnet, and described magnetic conductor comprises the magnetic conduction arm that at least one extends towards described medium to be detected, and described spatial accommodation arranges near described magnetic conduction arm.
4. magnetic according to claim 3 detects Magnetic Sensor, it is characterized in that, described magnetic conductor comprises two magnetic conduction arms that extend towards described medium to be detected, and described spatial accommodation is arranged between two described magnetic conduction arms.
5. detect Magnetic Sensor according to the magnetic described in claim 3 or 4, it is characterized in that, described magnetic conduction arm is perpendicular to the detection faces of described medium to be detected, so that the magnetic direction that described permanent magnet produces is perpendicular to the detection faces of described medium to be detected.
6. magnetic according to claim 3 detects Magnetic Sensor, it is characterized in that, described permanent magnet adopts neodymium iron boron, SmCo, and aluminium nickel cobalt, ferrite, permalloy, or silicon steel sheet is made.
7. magnetic according to claim 2 detects Magnetic Sensor, it is characterized in that, described spatial accommodation is blind hole or the through hole being arranged on described magnetic conductor.
8. magnetic according to claim 1 detects Magnetic Sensor, it is characterized in that, described weak magnetic strength unit comprises:
Winding, for generation of the magnetic field of magnetic anti-counterfeiting mark described in premagnetization;
Power supply, for providing electric energy to described winding;
Magnetic conductor, makes the magnetic field of described winding generation perpendicular to the sensitive surface of described chip.
9. magnetic according to claim 8 detects Magnetic Sensor, it is characterized in that, described magnetic conductor comprises magnetic conduction body and at least two magnetic conduction arms, and described magnetic conduction arm is symmetrical arranged along the periphery of described magnetic conduction body;
Described chip is arranged between described magnetic conduction arm, and the sensitive surface of described chip is towards described medium to be detected;
Winding described in magnetic conduction arm correspondence one described in each, described in each, winding is placed on the outside of magnetic conduction arm described in accordingly.
10. magnetic according to claim 9 detects Magnetic Sensor, it is characterized in that, described magnetic conductor comprises magnetic conduction body and two magnetic conduction arms, and two described magnetic conduction arms are relatively arranged at the both sides of described magnetic conduction body.
11. magnetic according to claim 8 detect Magnetic Sensor, it is characterized in that, described magnetic conductor comprises magnetic conduction body and the support portion of being located at described magnetic conduction body end, and described winding is placed on the outside of described magnetic conduction body;
Described chip is arranged at described support portion.
12. magnetic according to claim 1 detect Magnetic Sensor, it is characterized in that, the pad that described chip comprises at least one pair of magnetic sensitive film and is electrically connected with described magnetic sensitive film, is linked to be wheatstone bridge circuits by described pad and wire by described magnetic sensitive film.
13. magnetic according to claim 12 detect Magnetic Sensor, it is characterized in that, every described magnetic sensitive film is continuous continual magnetic sensitive film; Or,
Every described magnetic sensitive film comprises multistage magnetic sensitive film section and connects the conductor of described magnetic sensitive film section.
14. magnetic according to claim 12 detect Magnetic Sensor, it is characterized in that, on the length direction of described magnetic sensitive film, be provided with the inhibition unit that n segmentation suppresses the demagnetizing field of described magnetic sensitive film, described inhibition unit interval is arranged at the surperficial and/or inner of described magnetic sensitive film, wherein, the integer that n is >=2.
15. magnetic according to claim 14 detect Magnetic Sensor, it is characterized in that, described inhibition unit is otch, electric conductor, calandria, insulator or hard magnetic body.
16. magnetic according to claim 12 detect Magnetic Sensor, it is characterized in that, the magnetic line of force direction of described weak magnetic strength unit is vertical with the pinning direction of described magnetic sensitive film.
17. magnetic according to claim 12 detect Magnetic Sensor, it is characterized in that, described magnetic sensitive film is Hall effect film, anisotropic magnetoresistance film, giant magnet resistance film, tunnel magneto resistance film, giant magnetoresistance films or giant Hall effect film.
18. magnetic according to claim 12 detect Magnetic Sensor, it is characterized in that, comprise housing, wiring board, processing unit and capillary, wherein,
Described wiring board is electrically connected with described chip, the differential signal obtaining for delivery of described chip;
Described processing unit is for distinguishing described anti-counterfeiting mark according to described differential voltage signal;
Described chip and described wiring board are located in described housing; Described processing unit is located in described housing or is located at outside described housing;
Described capillary is electrically connected with described wiring board, and described capillary is used for the transmission of signal and supports described housing.
19. magnetic according to claim 18 detect Magnetic Sensor, it is characterized in that, on described housing, be provided with magnetic conductive hole, described chip is relative with described magnetic conductive hole.
20. magnetic according to claim 18 detect Magnetic Sensor, it is characterized in that, described housing adopts copper, aluminium or its oxide or plastic production.
21. magnetic according to claim 18 detect Magnetic Sensor, it is characterized in that, described housing adopts permalloy, ferrite or selenium steel disc to make; Or, adopt metal material or nonmetallic materials to make, and at its outside surface plating chromium, the coating of ferronickel or permalloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201310034302.6A CN103971444A (en) | 2013-01-29 | 2013-01-29 | Magnetic sensor for magnetic detection |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201310034302.6A CN103971444A (en) | 2013-01-29 | 2013-01-29 | Magnetic sensor for magnetic detection |
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| CN201310034302.6A Pending CN103971444A (en) | 2013-01-29 | 2013-01-29 | Magnetic sensor for magnetic detection |
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Application publication date: 20140806 |