CN116242237A - High-precision magnetic resistance micro-displacement detection device based on magnetic grid structure - Google Patents
High-precision magnetic resistance micro-displacement detection device based on magnetic grid structure Download PDFInfo
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- CN116242237A CN116242237A CN202310249456.0A CN202310249456A CN116242237A CN 116242237 A CN116242237 A CN 116242237A CN 202310249456 A CN202310249456 A CN 202310249456A CN 116242237 A CN116242237 A CN 116242237A
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- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
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Abstract
The invention belongs to the technical field of micro-displacement detection devices, and particularly relates to a high-precision magnetic resistance micro-displacement detection device based on a magnetic grid structure. The invention combines the magnetic grid structure with the tunnel magnetic resistance sensing element, reasonably utilizes the advantages of the magnetic grid structure and the tunnel magnetic resistance sensing element, and can realize high-precision micro-displacement measurement while ensuring the anti-interference capability. The magnetic grid is characterized in that a layer of nickel is electrochemically deposited on a silicon wafer, and then the nickel layer is magnetized through a pair of permanent magnets with opposite magnetism below the silicon wafer, so that a high-change-rate magnetic field is generated in the space of the upper surface of the magnetic grid.
Description
Technical Field
The invention belongs to the technical field of micro-displacement detection devices, and particularly relates to a high-precision magnetic resistance micro-displacement detection device based on a magnetic grid structure.
Background
The micro-displacement sensing technology is a sensing technology which has important influence on modern scientific research and industrial production, and has wide application in various important fields of national economy such as high-precision numerical control machine tools, aerospace, petrochemical industry and the like. To meet the increasing demands of various industries, especially modern industrial production, micro-displacement measurement is developing towards high precision, digitization, anti-interference, intellectualization and the like.
The working principle of the micro displacement sensor is that the displacement of an object is converted into a measurable electric signal, and the change of the micro displacement is obtained through the analysis of the electric signal. In industrial applications, more common displacement sensors are resistive, capacitive, inductive, ultrasonic, grating, magnetostrictive, etc. The resistive sensor has good linearity, simple structure and good stability, and becomes a mainstream means in the field of production process detection and production automation. However, the resistance type displacement sensor has the defects of easy abrasion and short time service life, and meanwhile, the measurement accuracy is not high. A capacitive displacement sensor is a sensor that performs displacement measurement by converting a displacement amount change into a capacitance change. Besides the non-contact type common friction-free characteristic, the device has the advantages of large signal-to-noise ratio, high precision stability, strong electromagnetic interference resistance and the like. The method is particularly suitable for measuring high-frequency vibration and small displacement, but the defects of the method are also obvious, such as susceptibility to parasitic capacitance, nonlinearity of output characteristics and the like. The grating is based on interference and diffraction phenomena of light, has very high resolution in the process of micro-displacement measurement, and can reach 0.1 mu m. The grating displacement sensor has the advantages of high resolution, good heat resistance, strong electromagnetic interference resistance, low energy consumption and the like. However, under severe environments such as floating dust and smoke, the interference and diffraction effects of light are very easy to influence, and meanwhile, the complex light path also makes the whole integration poor, so that the application of the light path is limited.
Disclosure of Invention
Aiming at the technical problems that the grating displacement sensor is extremely easy to influence the interference and diffraction effects of light in severe environments such as floating dust, smoke and the like, and the integral integration is poor due to a complex light path, the invention provides a high-precision magnetic resistance micro-displacement detection device based on a magnetic grating structure. The device has reasonable overall structural design, simple process and manufacture, strong realizability and high integration.
In order to solve the technical problems, the invention adopts the following technical scheme:
the utility model provides a little displacement detection device of high accuracy magnetic resistance based on magnetic grating structure, includes permanent magnet base plate, first permanent magnet, second permanent magnet, magnetic grating layer structure, magnetic resistance layer, the center department of permanent magnet base plate is equipped with square recess, inlay in the square recess of permanent magnet base plate has first permanent magnet and second permanent magnet, magnetic grating layer structure sets up on first permanent magnet and second permanent magnet, the magnetic resistance layer sets up on magnetic grating layer structure.
The magnetic grid layer structure comprises a magnetic grid substrate, an N-pole magnetization region, an S-pole magnetization region and a magnetic grid, wherein the magnetic grid substrate is arranged on the first permanent magnet and the second permanent magnet, the N-pole magnetization region and the S-pole magnetization region are arranged on the magnetic grid substrate, and the magnetic grid is arranged between the N-pole magnetization region and the S-pole magnetization region.
The magneto-resistive layer comprises a magneto-resistive substrate, a magneto-resistive element, a magneto-resistive lead wire and a test electrode Pad, wherein the magneto-resistive substrate is arranged on the magnetic gate substrate, the magneto-resistive element is arranged on the magneto-resistive substrate, and the magneto-resistive element is electrically connected with the test electrode Pad through the magneto-resistive lead wire.
The magnetic directions of the first permanent magnet and the second permanent magnet are opposite, the first permanent magnet and the second permanent magnet are made of NdFeB permanent magnet materials with the model number of N52, and the first permanent magnet and the second permanent magnet are symmetrically fixed on two sides in the square groove of the permanent magnet substrate in an adhesive mode.
The depth of the square groove of the permanent magnet substrate is larger than the thickness of the first permanent magnet and the second permanent magnet.
The N pole magnetization region, the S pole magnetization region and the magnetic grid are all obtained by depositing a nickel layer with the thickness of 20um on a silicon wafer through an electrochemical process
The magneto-resistive element adopts a tunnel magneto-resistive element with the model of Q8V20, the magneto-resistive element is composed of 13 pairs of tunnel magneto-resistive junctions, and each pair of tunnel magneto-resistive junctions is composed of two tunnel magneto-resistive junctions with opposite polarities in parallel.
The magnetic resistance substrate is connected with the magnetic resistance element in a bonding way, and a layer of gold grows on the magnetic resistance substrate through magnetron sputtering.
The test electrode Pad is electrically connected to the phase shifting circuit, the phase shifting circuit is electrically connected to the subdivision circuit, and the subdivision chip of the subdivision circuit adopts an iC-TW8 chip.
The permanent magnet substrate is made of silicon, ceramic or glass.
Compared with the prior art, the invention has the beneficial effects that:
the invention combines the magnetic grid structure with the tunnel magnetic resistance sensing element, reasonably utilizes the advantages of the magnetic grid structure and the tunnel magnetic resistance sensing element, and can realize high-precision micro-displacement measurement while ensuring the anti-interference capability. The magnetic grid is characterized in that a layer of nickel is electrochemically deposited on a silicon wafer, and then the nickel layer is magnetized through a pair of permanent magnets with opposite magnetism below the silicon wafer, so that a high-change-rate magnetic field is generated in the space of the upper surface of the magnetic grid. The invention adopts the tunnel magnetic resistance effect with high sensitivity to detect, and the resistance value of the tunnel magnetic resistance element can be changed drastically under the weak magnetic field change, thereby realizing the detection of micro displacement.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It will be apparent to those skilled in the art from this disclosure that the drawings described below are merely exemplary and that other embodiments may be derived from the drawings provided without undue effort.
The structures, proportions, sizes, etc. shown in the present specification are shown only for the purposes of illustration and description, and are not intended to limit the scope of the invention, which is defined by the claims, so that any structural modifications, changes in proportions, or adjustments of sizes, which do not affect the efficacy or the achievement of the present invention, should fall within the scope of the invention.
FIG. 1 is a schematic diagram of the overall structure of the present invention;
FIG. 2 is a schematic view of a permanent magnet substrate according to the present invention;
FIG. 3 is a schematic diagram of a magnetic gate layer structure according to the present invention;
FIG. 4 is a schematic diagram of a magnetoresistive layer structure according to the present invention;
FIG. 5 is a graph showing the magnetic field distribution of the sensitive axis direction of the surface of the magnetic grating according to the present invention;
FIG. 6 is a schematic diagram of a TMR bridge structure of the magnetoresistive element of the invention;
FIG. 7 is a flow chart of a phase shift subdivision circuit of the present invention;
FIG. 8 is a schematic diagram of a phase shifting circuit of the present invention;
fig. 9 is a schematic diagram of a subdivision circuit in accordance with the present invention.
Wherein: the magnetic field sensor comprises a permanent magnet substrate 1, a first permanent magnet 2, a second permanent magnet 3, a magnetic grid substrate 4, an N-pole magnetization region 5, an S-pole magnetization region 6, a magnetic grid 7, a magnetic resistance substrate 8, a magnetic resistance element 9, a magnetic resistance lead 10, a test electrode Pad 11, a phase shift circuit 12 and a subdivision circuit 13.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is apparent that the described embodiments are only some embodiments of the present application, but not all embodiments, and these descriptions are only for further illustrating the features and advantages of the present invention, not limiting the claims of the present invention; all other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.
The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.
In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context.
In this embodiment, as shown in fig. 1, the permanent magnet circuit board is composed of a permanent magnet substrate 1, a first permanent magnet 2, a second permanent magnet 3, a magnetic grid substrate 4, an N-pole magnetization region 5, an S-pole magnetization region 6, a magnetic grid 7, a magnetic resistance substrate 8, a magnetic resistance element 9, a magnetic resistance lead 10, and a test electrode Pad 11. As shown in fig. 2, the permanent magnet substrate 1 is square, the material can be silicon, ceramic, glass, etc., a square groove is formed in the center of the permanent magnet substrate 1, a pair of first permanent magnet 2 and second permanent magnet 3 with opposite magnetic directions are embedded in the square groove, the depth of the groove of the permanent magnet substrate 1 is slightly larger than the thickness of the first permanent magnet 2 and the second permanent magnet 3, the first permanent magnet 2 and the second permanent magnet 3 are neodymium iron boron permanent magnet materials with the model number of N52, the size and the size of the neodymium iron boron permanent magnet materials are consistent, the cuboid with the structure of 3mm multiplied by 2mm multiplied by 1mm is formed in the center of the permanent magnet substrate 1, and the length and the width of the cuboid are larger than the thickness. The first permanent magnet 2 and the second permanent magnet 3 are symmetrically fixed on two sides in the groove of the permanent magnet substrate 1 in an adhesive mode. Inside the first permanent magnet 2, the magnetic lines of force are directed from the lower surface S-pole to the upper surface N-pole, and inside the second permanent magnet 3, the magnetic lines of force are directed from the lower surface N-pole to the upper surface S-pole. Through the magnetizing mode, the first permanent magnet 2 and the second permanent magnet 3 can provide a pair of magnetizing magnetic fields with the same size and opposite directions for the magnetic grid 7.
In this embodiment, as shown in fig. 3, the magnetic grid layer structure may be divided into three parts of a support frame 4, an N-pole magnetization region 5, an S-pole magnetization region 6, and a magnetic grid 7. Wherein the N pole magnetization region 5, the S pole magnetization region 6 and the magnetic grid 7 are realized by depositing a nickel layer with the thickness of 20um on a silicon wafer through an electrochemical process.
When the N-pole magnetization region 5 shown in fig. 3 is magnetized by the first permanent magnet 2 directly below, a part of the magnetic grid connected thereto is also magnetized to the same magnetism as the N-pole magnetization region; similarly, when the S-pole magnetization region 6 is magnetized by the second permanent magnet 3 directly below, another part of the magnetic grid connected thereto is magnetized to the same magnetism as the S-pole magnetization region. In this way, the entire magnetic grid produces a high rate magnetic field of alternating polarity as shown in FIG. 5.
In the present embodiment, as shown in fig. 4, the magneto-resistive layer may be divided into three parts of the magneto-resistive element 9, the magneto-resistive wire 10, and the test electrode Pad 11. The magneto-resistive element 9 used in the present invention is a type Q8V20 tunnel magneto-resistive element provided by multidimensional technology company, the magneto-resistive element 9 is composed of 13 pairs of tunnel magneto-resistive junctions, each pair is composed of two tunnel magneto-resistive junctions with opposite polarities in parallel. In order to detect the resistance change of the magneto-resistive element, the invention adopts a bonding mode to bond the magneto-resistive element 9 and the magneto-resistive substrate 8 together, and simultaneously a layer of gold is grown on the magneto-resistive substrate 8 by magnetron sputtering to manufacture the magneto-resistive lead 10 and the test Pad 11.
When the magneto-resistive displacement sensor of the embodiment works, the first permanent magnet 2, the second permanent magnet 3 and the magnetic grid layer can be arranged on the fixed frame according to different practical conditions, and the magneto-resistive element 9 is arranged on a displacement table capable of moving in the horizontal direction; the magneto-resistive element may be disposed on a fixed frame, and the first permanent magnet 2, the second permanent magnet 3, and the magnetic grid layer may be mounted on a displacement table that is movable in the horizontal direction, that is, the relative positions of the first permanent magnet 2, the second permanent magnet 3, and the magnetic grid 7 may be fixed, and the relative positions with the magneto-resistive element 9 may be changed in the horizontal direction. When the magnetic grating is in operation, the magneto-resistive element 9 is placed at the position 100um above the magnetic grating 7, when the magneto-resistive element 9 and the magneto-resistive element are in relative displacement in the horizontal direction, the phase-shifting subdivision circuit flow is shown in fig. 7, the magneto-resistive element 9 senses the magnetic field change shown in fig. 5, two output sine signals with 90 degrees phase difference can be output through a bridge circuit shown in fig. 6, then the sine signals output by the bridge circuit are connected into the phase-shifting circuit 12 shown in fig. 8, the phase-shifting circuit 12 can carry out real-time phase shifting on the periodic sine signals generated in the micro-displacement test process, amplitude errors and phase errors possibly introduced in the test are effectively restrained, orthogonality of the two sine and cosine signals is guaranteed, then the two orthogonal signals are input into the subdivision circuit 13 shown in the circuit principle shown in fig. 9, a subdivision chip used by the subdivision circuit is a special DSP interpolator iC-TW8 produced by IC-Haus company, the subdivision chip can provide different subdivision factors according to different subdivision requirements, and the phase-shifting circuit 13 can realize high-quality subdivision of the phase-shifting circuit. According to the size parameters of the magnetic grid, the period of an output signal passing through the bridge circuit is hundred micrometers, and after 10000 times of subdivision of the subdivision circuit, the resolution of the sensor can reach tens of nanometers.
The preferred embodiments of the present invention have been described in detail, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present invention, and the various changes are included in the scope of the present invention.
Claims (10)
1. A high-precision magnetic resistance micro-displacement detection device based on a magnetic grid structure is characterized in that: the permanent magnet structure comprises a permanent magnet substrate (1), a first permanent magnet (2), a second permanent magnet (3), a magnetic grid layer structure and a magnetic resistance layer, wherein a square groove is formed in the center of the permanent magnet substrate (1), the first permanent magnet (2) and the second permanent magnet (3) are embedded in the square groove of the permanent magnet substrate (1), the magnetic grid layer structure is arranged on the first permanent magnet (2) and the second permanent magnet (3), and the magnetic resistance layer is arranged on the magnetic grid layer structure.
2. The high-precision magneto-resistive micro-displacement detection device based on the magnetic grid structure as claimed in claim 1, wherein: the magnetic grid layer structure comprises a magnetic grid substrate (4), an N pole magnetization region (5), an S pole magnetization region (6) and a magnetic grid (7), wherein the magnetic grid substrate (4) is arranged on the first permanent magnet (2) and the second permanent magnet (3), the N pole magnetization region (5) and the S pole magnetization region (6) are arranged on the magnetic grid substrate (4), and the magnetic grid (7) is arranged between the N pole magnetization region (5) and the S pole magnetization region (6).
3. The high-precision magneto-resistive micro-displacement detection device based on the magnetic grid structure as claimed in claim 1, wherein: the magnetic resistance layer comprises a magnetic resistance substrate (8), a magnetic resistance element (9), a magnetic resistance lead wire (10) and a test electrode Pad (11), wherein the magnetic resistance substrate (8) is arranged on the magnetic grid substrate (4), the magnetic resistance element (9) is arranged on the magnetic resistance substrate (8), and the magnetic resistance element (9) is electrically connected with the test electrode Pad (11) through the magnetic resistance lead wire (10).
4. The high-precision magneto-resistive micro-displacement detection device based on the magnetic grid structure as claimed in claim 1, wherein: the magnetic directions of the first permanent magnet (2) and the second permanent magnet (3) are opposite, the first permanent magnet (2) and the second permanent magnet (3) are made of NdFeB permanent magnet materials with the model number of N52, and the first permanent magnet (2) and the second permanent magnet (3) are symmetrically fixed on two sides in the square groove of the permanent magnet substrate (1) in an adhesive mode.
5. The high-precision magneto-resistive micro-displacement detection device based on the magnetic grid structure as claimed in claim 1, wherein: the depth of the square groove of the permanent magnet substrate (1) is larger than the thickness of the first permanent magnet (2) and the second permanent magnet (3).
6. The high-precision magneto-resistive micro-displacement detection device based on the magnetic grid structure as claimed in claim 2, wherein: the N pole magnetization region (5), the S pole magnetization region (6) and the magnetic grid (7) are all obtained by depositing a nickel layer with the thickness of 20um on a silicon wafer through an electrochemical process.
7. A high-precision magneto-resistive micro-displacement detection device based on a magnetic grid structure as claimed in claim 3, wherein: the magneto-resistive element (9) adopts a tunnel magneto-resistive element with the model number of Q8V20, the magneto-resistive element (9) is composed of 13 pairs of tunnel magneto-resistive junctions, and each pair of tunnel magneto-resistive junctions is composed of two tunnel magneto-resistive junctions with opposite polarities in parallel.
8. A high-precision magneto-resistive micro-displacement detection device based on a magnetic grid structure as claimed in claim 3, wherein: the magnetic resistance substrate (8) is connected with the magnetic resistance element (9) in a bonding way, and a layer of gold is grown on the magnetic resistance substrate (8) through magnetron sputtering.
9. A high-precision magneto-resistive micro-displacement detection device based on a magnetic grid structure as claimed in claim 3, wherein: the test electrode Pad (11) is electrically connected to the phase shifting circuit (12), the phase shifting circuit (12) is electrically connected to the subdivision circuit (13), and an iC-TW8 chip is adopted as a subdivision chip of the subdivision circuit (13).
10. The high-precision magneto-resistive micro-displacement detection device based on the magnetic grid structure as claimed in claim 1, wherein: the permanent magnet substrate (1) is made of silicon, ceramic or glass.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310249456.0A CN116242237A (en) | 2023-03-15 | 2023-03-15 | High-precision magnetic resistance micro-displacement detection device based on magnetic grid structure |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310249456.0A CN116242237A (en) | 2023-03-15 | 2023-03-15 | High-precision magnetic resistance micro-displacement detection device based on magnetic grid structure |
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| Publication Number | Publication Date |
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| CN116242237A true CN116242237A (en) | 2023-06-09 |
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| CN202310249456.0A Pending CN116242237A (en) | 2023-03-15 | 2023-03-15 | High-precision magnetic resistance micro-displacement detection device based on magnetic grid structure |
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| CN (1) | CN116242237A (en) |
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- 2023-03-15 CN CN202310249456.0A patent/CN116242237A/en active Pending
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