CN202693779U - Sensor for identifying magnetism of medium - Google Patents
Sensor for identifying magnetism of medium Download PDFInfo
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- CN202693779U CN202693779U CN2012202890593U CN201220289059U CN202693779U CN 202693779 U CN202693779 U CN 202693779U CN 2012202890593 U CN2012202890593 U CN 2012202890593U CN 201220289059 U CN201220289059 U CN 201220289059U CN 202693779 U CN202693779 U CN 202693779U
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Abstract
The utility model discloses a sensor for identifying the magnetism of a medium. The sensor comprises a chip (21), a printed circuit board (22) and an output lead pin (23), wherein an input end and an output end of the chip (21) are respectively welded with a corresponding wiring terminal on the printed circuit board (22); and one end of the output lead pin (23) is welded with the corresponding wiring terminal on the printed circuit board (22), so that the output ends and the input ends of the output lead pin (23) and the chip (21) are conducted. The sensor is suitable for identifying the magnetism of the medium made of a hard magnetic material. The sensor adopts an MTJ (Magnetic Tunnel Junction) element; compared with an indium antimonide Hall element, the flexibility and the signal to noise ratio of the MTJ element are high, so that the flexibility and the signal to noise ratio of the sensor are high. The MTJ element is suitable for large-batch production, a preparation process is simple and developed and is not easily influenced by temperature and stress, and the finished product rate is high, so that the machining process of the senor is simpler and the cost is lower. The sensor is not required to be provided with a permanent magnet so that the structure is simple and the cost is lower.
Description
Technical field
The utility model relates to the Magnetic Sensor technical field, and is particularly a kind of for the identification medium sensor of bank note and magnetic card magnetic for example.
Background technology
In the daily life, the medium for example application of bank note and magnetic card is very extensive.Usually, medium for example bank note and magnetic card magnetic very a little less than, therefore, the sensor that is used for identification medium magnetic for example magnetic head of cash inspecting machine need to have high sensitivity, low noise and high s/n ratio.
In the prior art, the sensor that is used for identification medium magnetic adopts indium antimonide (InSb) Hall element usually.This kind sensor has following shortcoming:
(1) sensitivity of indium antimonide Hall unit and signal to noise ratio (S/N ratio) are very low, cause the sensitivity of this kind sensor and signal to noise ratio (S/N ratio) very low;
(2) complex manufacturing technology of indium antimonide Hall unit, and be subjected to the impact of temperature and stress very obvious, yield rate is low, causes the processing technology of this kind sensor complicated, and cost is high;
(3) this kind sensor is provided with permanent magnet, and structure is complicated, and cost is higher.
Be starved of a kind of highly sensitive, signal to noise ratio (S/N ratio) is high, simple in structure, cost is low is used for the sensor of identification medium magnetic.
The utility model content
The purpose of this utility model provides a kind of sensor for identification medium magnetic.
The sensor that is used for identification medium magnetic that the utility model provides, comprise that chip, printed-wiring board (PWB) and output draws pin, the input end of described chip and output terminal respectively with described printed-wiring board (PWB) on respective terminal welding, the respective terminal welding of an end and the described printed-wiring board (PWB) of pin is drawn in described output, so that input end and the output terminal conducting of pin and described chip are drawn in described output.
Preferably, described sensor further comprises metal shell, be placed in wherein in order to described chip, printed-wiring board (PWB), output are drawn pin, permanent magnet, flexible circuit board, and an end opening of described metal shell, an end relative with this openend is detection faces.
Preferably, described metal shell is provided with the grounding lead pin.
Preferably, the material of described metal shell is non magnetic high-abrasive material.
Preferably, the thickness of the detection faces of described metal shell is less than or equal to 0.2mm.
Preferably, described sensor further comprises injection mold, places described metal shell inner, in order to described chip, printed-wiring board (PWB) are fixed.
Preferably, the shape and size of described injection mold are mated with the shape and size of described chip, described printed-wiring board (PWB) and described shell respectively, and the inside surface close contact of the outward flange of described injection mold and shell is with fixing described chip and described printed-wiring board (PWB).
Preferably, described injection mold is provided with through hole, and the position of described through hole and size are drawn respectively position and the size coupling of pin with described output, can pass described through hole so that pin is drawn in described output.
Preferably, described chip comprises at least one electric bridge, and each brachium pontis of this electric bridge comprises at least one MTJ(MTJ Magnetic Tunel Junction) element.
Preferably, described electric bridge is the gradient half-bridge, and the sensitive direction of the MTJ element of two brachium pontis is identical in the described electric bridge, and two MTJ elements of two brachium pontis lay respectively at the different position of magnetic field value.
Preferably, described electric bridge is the gradient full-bridge, the sensitive direction of the MTJ element of all brachium pontis is identical in the described gradient full-bridge, and two MTJ elements of relative position brachium pontis are positioned at the same position of magnetic field value in the full-bridge, and two MTJ elements of adjacent position brachium pontis are positioned at the different position of magnetic field value.
The utlity model has following beneficial effect:
(1) described sensor is applicable to identify the magnetic of the medium of being made by retentive material;
(2) described sensor adopts the MTJ element, compares with indium antimonide Hall unit, and sensitivity and the signal to noise ratio (S/N ratio) of MTJ element are high, and therefore sensitivity and the signal to noise ratio (S/N ratio) of described sensor are high;
(3) manufacture craft of MTJ element is compatible mutually with existing semiconductor microactuator process for machining and manufacturing, can adopt existing micro-processing technology to process, and is fit to large-scale mass production, and cost is low;
(4) manufacture craft of MTJ element is simpler, and is not subject to the impact of temperature and stress, and yield rate is high, and therefore the processing technology of described sensor is simpler, and cost is lower;
(5) described sensor does not need to arrange permanent magnet, and is simple in structure, and cost is lower.
Description of drawings
The schematic diagram of the sensor of the magnetic that is used for identification bank note and magnetic card that Fig. 1 provides for the comparative example of prior art;
The schematic diagram of the sensor of the magnetic that is used for identification bank note and magnetic card that Fig. 2 provides for the utility model embodiment.
Embodiment
Below in conjunction with drawings and Examples utility model content of the present utility model is further described.
At first in conjunction with the comparative example of prior art, specify the technical problems to be solved in the utility model, and be used for comparing to illustrate the beneficial effects of the utility model with each embodiment of the present utility model that is about to provide.
The comparing embodiment of prior art:
In comparing embodiment, as shown in Figure 1, the sensor that is used for identification medium magnetic comprises chip 11, printed-wiring board (PWB) (PCB) 12, exports and draw pin 13, metal shell 14, permanent magnet 15 and injection mold (not shown).One end opening of metal shell 14.Chip 11 and permanent magnet 15 are located at respectively the both sides of printed-wiring board (PWB) 12.Directly do not contact between printed-wiring board (PWB) 12 and the permanent magnet 15.The input end of chip 11 and output terminal respectively with printed-wiring board (PWB) 12 on respective terminal welding.Printed-wiring board (PWB) 12 is used for supporting and fixed chip 11.The respective terminal welding of an end and the printed-wiring board (PWB) 12 of pin 13 is drawn in output, so that input end and the output terminal conducting of pin 13 and chip 11 are drawn in output.The other end that pin 13 is drawn in output be used for will from the signal output of chip 11 for.Chip 11 adopts indium antimonide Hall unit.Metal shell 14 is provided with grounding lead pin 16.Metal shell 14 is used for the electromagnetic interference (EMI) of shielding except described sensor, and is used for eliminating static.Permanent magnet 15 be shaped as for example cuboid.The shape and size of injection mold are mated with the shape and size of chip 11, printed-wiring board (PWB) 12, metal shell 14 and permanent magnet 15 respectively, be used for fixed chip 11, printed-wiring board (PWB) 12 and permanent magnet 15, and be used for printed-wiring board (PWB) 12 and permanent magnet 15 are separated.
Can be found out by above-mentioned comparative example, because the chip of described sensor adopts indium antimonide Hall unit, the sensitivity of described sensor and signal to noise ratio (S/N ratio) are very low; Described sensor is provided with permanent magnet, and structure is complicated, and cost is higher.
Embodiment of the present utility model:
As shown in Figure 2, the sensor that is used for identification medium magnetic that the present embodiment provides comprises chip 21, printed-wiring board (PWB) 22, exports and draw pin 23, metal shell 24 and injection mold (not shown).Metal shell 24 adopts non magnetic high-abrasive material, and the one end opening, and an end relative with this openend is detection faces, and the thickness of detection faces is less than or equal to 0.2mm.The input end of chip 21 and output terminal respectively with printed-wiring board (PWB) 22 on respective terminal welding.Printed-wiring board (PWB) 22 is used for supporting and fixed chip 21, and chip 21 is installed near the detection faces of metal shell 24.The respective terminal welding of an end and the printed-wiring board (PWB) 22 of pin 23 is drawn in output, so that input end and the output terminal conducting of pin 23 and chip 21 are drawn in output.The other end that pin 23 is drawn in output be used for will from the signal output of chip 21 for.Chip 21 comprises at least one electric bridge, and this electric bridge is gradient half-bridge or gradient full-bridge, and each brachium pontis of this electric bridge comprises at least one magnetic tunnel-junction (MTJ, Magnetic Tunel Junction) element.
In the present embodiment, chip 21 comprises for example gradient full-bridge, and each brachium pontis of this gradient full-bridge comprises for example MTJ element.The sensitive direction of the MTJ element of all brachium pontis is identical in the described gradient full-bridge, and two MTJ elements of relative position brachium pontis are positioned at the same position of magnetic field value in the full-bridge, and two MTJ elements of adjacent position brachium pontis are positioned at the different position of magnetic field value.
Injection mold described in the present embodiment is a kind of special-shaped structural part, the shape and size of injection mold (not shown) are mated with the shape and size of chip 21, printed-wiring board (PWB) 22 and metal shell 24 respectively, and the inside surface close contact of the outward flange of injection mold and metal shell 24 is used for fixed chip 21 and printed-wiring board (PWB) 22.Injection mold also is provided with through hole, and the position of this through hole and size are drawn respectively position and the size coupling of pin 23 with output, so that the through hole that pin 23 can pass injection mold is drawn in output.
When using described sensor, medium for example bank note moves near the detection faces of described sensor and with respect to this detection faces, the magnetic that chip senses bank note is at the MTJ of chip element sensitive direction changing magnetic field component and draw the pin output signal by output in gradient, thereby realize the identification to bank note magnetic, be used for judging the power with magnetic of having or not of magnetic.
Described sensor is applicable to identify the magnetic of the medium of being made by retentive material.Described sensor adopts the MTJ element, compares with indium antimonide Hall unit, and sensitivity and the signal to noise ratio (S/N ratio) of MTJ element are high, and therefore sensitivity and the signal to noise ratio (S/N ratio) of described sensor are high.The manufacture craft of MTJ element is compatible mutually with existing semiconductor microactuator process for machining and manufacturing, can adopt existing micro-processing technology to process, and is fit to large-scale mass production, and cost is low.The manufacture craft of MTJ element is simpler, and is not subject to the impact of temperature and stress, and yield rate is high, and therefore the processing technology of described sensor is simpler, and cost is lower.Described sensor does not need to arrange permanent magnet, and is simple in structure, and cost is lower.
Should be appreciated that the above detailed description of the technical solution of the utility model being carried out by preferred embodiment is illustrative and not restrictive.Those of ordinary skill in the art can make amendment to the technical scheme that each embodiment puts down in writing on the basis of reading the utility model instructions, perhaps part technical characterictic wherein is equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution break away from the spirit and scope of each embodiment technical scheme of the utility model.
Claims (10)
1. sensor that is used for identification medium magnetic, it is characterized in that, comprise that chip (21), printed-wiring board (PWB) (22) and output draws pin (23), the input end of described chip (21) and output terminal respectively with described printed-wiring board (PWB) (22) on respective terminal welding, the respective terminal welding of an end and the described printed-wiring board (PWB) (22) of pin (23) is drawn in described output, so that input end and the output terminal conducting of pin (23) and described chip (21) are drawn in described output.
2. the sensor for identification medium magnetic according to claim 1, it is characterized in that, described sensor further comprises metal shell (24), be placed in wherein in order to described chip (21), printed-wiring board (PWB) (22), output are drawn pin (23), permanent magnet, flexible circuit board, one end opening of described metal shell (24), an end relative with this openend is detection faces.
3. the sensor for identification medium magnetic according to claim 2 is characterized in that, described metal shell (24) is provided with grounding lead pin (25).
4. the sensor for identification medium magnetic according to claim 2 is characterized in that, the material of described metal shell (24) is non magnetic high-abrasive material.
5. the sensor for identification medium magnetic according to claim 2 is characterized in that, the thickness of the detection faces of described metal shell (24) is less than or equal to 0.2mm.
6. the sensor for identification medium magnetic according to claim 1 is characterized in that, described sensor further comprises injection mold, places described metal shell inner, in order to described chip (21), printed-wiring board (PWB) (22) are fixed.
7. the sensor for identification medium magnetic according to claim 6, it is characterized in that, described injection mold is provided with through hole, the position of described through hole and size are drawn respectively position and the size coupling of pin (23) with described output, can pass described through hole so that pin (23) is drawn in described output.
8. the sensor for identification medium magnetic according to claim 1 is characterized in that, described chip (21) comprises at least one electric bridge, and each brachium pontis of this electric bridge comprises at least one MTJ element.
9. the sensor for identification medium magnetic according to claim 8, it is characterized in that, described electric bridge is the gradient half-bridge, and the sensitive direction of the MTJ element of two brachium pontis is identical in the described electric bridge, and two MTJ elements of two brachium pontis lay respectively at the different position of magnetic field value.
10. the sensor for identification medium magnetic according to claim 8, it is characterized in that, described electric bridge is the gradient full-bridge, the sensitive direction of the MTJ element of all brachium pontis is identical in the described gradient full-bridge, and two of the relative position brachium pontis MTJ elements are positioned at the same position of magnetic field value in the full-bridge, and two MTJ elements of adjacent position brachium pontis are positioned at the different position of magnetic field value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012202890593U CN202693779U (en) | 2012-06-19 | 2012-06-19 | Sensor for identifying magnetism of medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012202890593U CN202693779U (en) | 2012-06-19 | 2012-06-19 | Sensor for identifying magnetism of medium |
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| Publication Number | Publication Date |
|---|---|
| CN202693779U true CN202693779U (en) | 2013-01-23 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2012202890593U Expired - Fee Related CN202693779U (en) | 2012-06-19 | 2012-06-19 | Sensor for identifying magnetism of medium |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102721938A (en) * | 2012-06-19 | 2012-10-10 | 兰州大学 | Sensor for identifying magnetism of medium |
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2012
- 2012-06-19 CN CN2012202890593U patent/CN202693779U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102721938A (en) * | 2012-06-19 | 2012-10-10 | 兰州大学 | Sensor for identifying magnetism of medium |
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130123 Termination date: 20150619 |
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| EXPY | Termination of patent right or utility model |