Amorphous wire sensor and preparation method thereof

Abstract

The invention discloses an amorphous wire sensor and a preparation method thereof. The miniature amorphous wire sensor comprises a substrate, and a bottom coil, an amorphous wire, an arched coil, a metal bonding pad, an amorphous wire signal lead and a coil signal lead which are connected to the substrate. Wherein the bottom-layer coil is connected to the substrate, a metal bonding pad is arranged on the bottom-layer coil, the amorphous wire extends along the bottom-layer coil, the end of the amorphous wire is wrapped by the metal bonding pad on the bottom-layer coil to achieve electric connection, and the two ends of the arch-shaped coil are bent, inclined and extend to be connected with the bottom-layer coil. A supporting layer formed by curing a supporting material is arranged between the arched coil and the bottom layer coil, the arched coil is isolated from the amorphous wire through the supporting layer, the amorphous wire signal lead is electrically connected with the metal bonding pad, and the coil signal lead is electrically connected with the arched coil. The size of the sensor can be reduced on the premise of ensuring the consistency of the device, the production efficiency of the sensor is improved, and the purpose of batch production of the miniature amorphous wire sensor is achieved.

Description

Technical Field

[0001] The present application relates to the field of magnetic sensing technology, and in particular to an amorphous wire sensor and a preparation method thereof. Background Art

[0002] The emergence of giant magneto-impedance (GMI) has promoted the development of high-precision weak magnetic detection technology. Magnetic sensors based on the GMI effect are widely used in the fields of ocean, aerospace, target survey, medical instruments and military industry. Compared with soft magnetic materials such as amorphous films and amorphous ribbons, amorphous microwires (also known as amorphous wires) have a more significant GMI effect. GMI sensors with amorphous wires as magnetic sensitive materials have attracted widespread attention in the field of weak magnetic detection due to their high sensitivity, non-contact, and almost no hysteresis. In traditional technology, amorphous microwires, as a kind of special-shaped soft magnetic material, are usually electrically connected by welding process, and an inductor coil is wound around the amorphous microwire to complete the preparation of the magnetic sensor. This processing method has the disadvantages of large device size, poor coil consistency, and large floating resistance of the welding port. Summary of the invention

[0003] Based on this, it is necessary to provide an amorphous wire sensor and a preparation method thereof, which can reduce the volume of the sensor and improve the production efficiency of the sensor while ensuring the consistency of the device, so as to achieve the purpose of mass production of micro amorphous wire sensors.

[0004] An embodiment of the present application provides a method for preparing an amorphous wire sensor.

[0005] A method for preparing an amorphous wire sensor comprises the following steps:

[0006] Prepare a first metal seed layer, a bottom coil and a first metal sub-pad connected in a stacked manner on the surface of the substrate, fix the amorphous wire on the bottom coil and place two ends of the amorphous wire on the first metal sub-pad respectively;

[0007] Spin-coating photoresist to cover the amorphous wire and the bottom coil, and after drying, exposure, and development, exposing a portion of the amorphous wire fixed on the first metal sub-pad, and removing the outer glass layer of the exposed amorphous wire;

[0008] After removing the residual photoresist on the amorphous wire and the bottom coil, a support material containing non-photosensitive polyimide is spin-coated on the surface of the substrate, and a covering layer is obtained by drying. A photoresist is spin-coated on the surface of the covering layer, and a second patterned groove with a curved inner wall is obtained through drying, exposure, and development. The second patterned groove separates the covering layer into a support layer located on the bottom coil and wrapping the amorphous wire, and a wrapping layer located on the substrate and wrapping the bottom coil;

[0009] Removing the residual photoresist on the support layer and the encapsulation layer, and baking the support layer and the encapsulation layer in an oxygen-free environment to imide them;

[0010] A second metal seed layer, a second metal sub-pad and a plurality of arch coils are sequentially stacked and connected on the surfaces of the support layer and the wrapping layer, an end of the amorphous wire is wrapped between the first metal sub-pad and the second metal sub-pad, and the arch coil extends in a curved shape along the surface of the support layer and covers the amorphous wire.

[0011] In some embodiments, when a first metal seed layer, a bottom layer coil, and a first metal sub-pad are sequentially prepared on a substrate surface, the following steps are included:

[0012] Prepare the first metal seed layer on the surface of the substrate;

[0013] Spin-coating photoresist on the surface of the first metal seed layer, and obtaining a patterned first groove after drying, exposure and development;

[0014] Electroplating the bottom layer coil and the first metal sub-pad in the patterned first groove;

[0015] After removing the residual photoresist, the exposed first metal seed layer is removed by etching.

[0016] In some embodiments, the preparation method further satisfies at least one of the following conditions:

[0017] (1) Before preparing the first metal seed layer on the substrate, the method further comprises the steps of washing the substrate with acetone, isopropanol and pure water in sequence and then drying the substrate;

[0018] (2) The first metal seed layer is made of Cr and / or Cu;

[0019] (3) The preparation method of the first metal seed layer includes a magnetron sputtering process, wherein the magnetron sputtering power is 600W~700W, and the sputtering rate is 4.22 Å / s~6.59Å / s;

[0020] (4) The thickness of the first metal seed layer is 600Å~2000Å;

[0021] (5) When the bottom layer coil and the first metal sub-pad are prepared by electroplating in the patterned first groove, the electroplating solution is a CuSO4 solution, the electroplating current is 0.243A~0.3A, and the electroplating time is 480s~660s.

[0022] In some embodiments, the preparation method further satisfies at least one of the following conditions:

[0023] (1) using an HF solution to remove the exposed outer glass layer of the amorphous wire, wherein the concentration of the HF solution is 3% to 5%, and the HF solution etching time is 30 min to 35 min;

[0024] (2) The thickness of the support material containing non-photosensitive polyimide is spin-coated to 40 μm to 60 μm;

[0025] (3) When the support layer is baked at high temperature in an oxygen-free environment, the baking temperature is gradually increased from 60°C to 350°C, and the baking time is 9h~15h;

[0026] (4) The thickness of the second metal seed layer is 600Å~2000Å.

[0027] In some embodiments, when a second metal seed layer, a second metal sub-pad, and a plurality of arched coils are sequentially prepared on the surface of the support layer and the wrapping layer in a stacked manner, the following steps are included:

[0028] Preparing a second metal seed layer on the surface of the support layer and the wrapping layer, spin-coating a photoresist on the second metal seed layer, and drying, exposing, and developing a portion of the photoresist at the support layer and the second groove adjacent to the support layer to expose a portion of the second metal seed layer;

[0029] The second metal sub-pad is prepared by electroplating on the second metal seed layer with exposed ends, the end of the amorphous wire is wrapped between the first metal sub-pad and the second metal sub-pad, and the arched coil is prepared on the second metal seed layer with non-exposed ends;

[0030] After removing the photoresist, the exposed second metal seed layer is removed by etching.

[0031] In some embodiments, the preparation method further satisfies at least one of the following conditions:

[0032] (1) preparing the second metal seed layer on the surface of the imidized support layer by a magnetron sputtering process, wherein the magnetron sputtering power is 600 W to 700 W and the sputtering rate is 4.22 Å / s to 6.59 Å / s;

[0033] (2) When the second metal sub-pad and the arch coil are prepared by electroplating on the exposed second metal seed layer at the end, the electroplating solution is a CuSO4 solution, the electroplating current is 0.243A~0.3A, and the electroplating time is 480s~660s.

[0034] In some embodiments, the preparation method further satisfies at least one of the following conditions:

[0035] (1) The thickness of the spin-coated photoresist is 8μm~12μm;

[0036] (2) The baking temperature for drying the photoresist is 100°C~120°C, and the baking time is 180s~300s;

[0037] (3) Hard contact exposure is used for photoresist exposure, and the exposure dose is 300mj~600mj;

[0038] (4) The developing solution for developing the photoresist is an alkaline solution containing TMAH group, and the developing time is 3min~6min.

[0039] (5) When removing the residual photoresist on the amorphous wire and the bottom coil, and the residual photoresist on the surface of the first metal seed layer, the residual photoresist is soaked in acetone and then washed with isopropyl alcohol and pure water in sequence, wherein the acetone soaking time is 10 min to 20 min; when removing the residual photoresist on the supporting layer, the residual photoresist is soaked in propylene glycol monomethyl ether acetate solution and then washed with pure water.

[0040] An embodiment of the present application provides an amorphous wire sensor.

[0041] An amorphous wire sensor comprises a substrate and a bottom coil, an amorphous wire, an arch coil, a metal pad, an amorphous wire signal lead and a coil signal lead connected to the substrate; wherein the bottom coil is connected to the substrate, the metal pad is provided on the bottom coil, the amorphous wire extends along the bottom coil and the end of the amorphous wire is wrapped by the metal pad on the bottom coil to achieve electrical connection, the arch coil is bent and covers the amorphous wire, the two ends of the arch coil are bent and inclined and extend to the bottom coil, the two ends of the arch coil are respectively connected to the bottom coil, a supporting layer formed by solidifying a supporting material is provided between the arch coil and the bottom coil, the arch coil and the amorphous wire are isolated by part of the supporting layer, the height of the supporting layer from the bottom coil is greater than the diameter of the amorphous wire, the amorphous wire signal lead is electrically connected to the metal pad, and the coil signal lead is electrically connected to the arch coil.

[0042] In some embodiments, the amorphous wire sensor also includes a wrapping layer, which is connected to the substrate and wraps and covers part of the bottom coil, part of the amorphous wire and part of the arch coil, wherein the metal pad wrapping the end of the amorphous wire, the top surface of the arch coil, the amorphous wire signal lead and the coil signal lead are all exposed from the wrapping layer.

[0043] In some embodiments, the encapsulation layer is formed of a support material containing non-photosensitive polyimide.

[0044] In some embodiments, the top surface of the arched coil is parallel to the substrate and two side portions of the top surface are respectively curved in an arc shape, and the width of the top surface of the arched coil is greater than the diameter of the amorphous wire;

[0045] And / or, the height between the support layer and the bottom coil is 40 μm-60 μm.

[0046] In some embodiments, the lines of the bottom coil and the extension direction of the amorphous wire have an angle ranging from 45° to 60° in the horizontal plane;

[0047] And / or, the bottom layer coil as a whole extends in a strip shape on the substrate.

[0048] And / or, the substrate is a glass substrate.

[0049] The amorphous wire sensor of the present invention overcomes the shortcomings of traditional amorphous wire GMI magnetic sensors such as low production efficiency, poor device consistency, and large size. It realizes the electrical connection of the amorphous wire and the preparation of the three-dimensional arched coil by using an electroplating process based on MEMS technology. It uses a supporting material containing non-photosensitive polyimide to form a supporting layer to enhance the stability of the coil, while optimizing the structure and preparation process of the three-dimensional coil, reducing the production cost and process complexity. Under the premise of ensuring device consistency, the amorphous wire sensor reduces the size of the amorphous wire sensor and improves the production efficiency of the sensor, thereby achieving the purpose of mass production of miniature amorphous wire sensors.

[0050] The preparation method of the amorphous wire sensor of the present invention utilizes the MEMS process to realize the combination of wire and wafer. Under the premise of ensuring performance and consistency, a supporting material containing non-photosensitive polyimide is used to simplify the preparation process of the three-dimensional arch coil, improve the stability of the arch coil, complete the integration of the arch coil and the amorphous wire, and realize the batch production of miniaturized amorphous wire sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0052] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings. In the following description, the same reference numerals represent the same parts.

[0053] FIG1 is a schematic diagram of step S1 in the preparation method described in Example 1 of the present invention;

[0054] FIG2 is a schematic diagram of step S2 in the preparation method described in Example 1 of the present invention;

[0055] FIG3 is a schematic diagram of step S3 in the preparation method described in Example 1 of the present invention;

[0056] FIG4 is a schematic diagram of step S4 in the preparation method described in Example 1 of the present invention;

[0057] FIG5 is a schematic diagram of step S5 in the preparation method described in Example 1 of the present invention;

[0058] FIG6 is a schematic diagram of step S6 in the preparation method described in Example 1 of the present invention;

[0059] FIG7 is a schematic diagram of step S10 in the preparation method according to Example 1 of the present invention;

[0060] FIG8 is a schematic diagram of step S10 in the preparation method according to Example 1 of the present invention;

[0061] FIG9 is a schematic diagram of step S11 in the preparation method according to Example 1 of the present invention;

[0062] FIG10 is a schematic diagram of step S13 in the preparation method according to Example 1 of the present invention;

[0063] FIG11 is a schematic diagram of step S14 in the preparation method described in Example 1 of the present invention;

[0064] FIG12 is a schematic diagram of step S15 in the preparation method described in Example 1 of the present invention;

[0065] FIG13 is a schematic diagram of step S16 in the preparation method according to Example 1 of the present invention;

[0066] FIG14 is a schematic diagram of the structure of an amorphous wire sensor prepared by the preparation method described in Example 1 of the present invention;

[0067] FIG15 is a physical picture of the amorphous wire sensor prepared by the preparation method described in Example 1 of the present invention.

[0068] Description of Reference Numerals

[0069] 10. Amorphous wire sensor; 100. Substrate; 200. Bottom coil; 300. Amorphous wire; 400. Arch coil; 500. Metal pad; 600. Amorphous wire signal lead; 700. Coil signal lead; 801. First metal seed layer; 802. Second metal seed layer; 901, 902, 903. Photoresist; 1001. Patterned first groove; 1002. Patterned second groove; 1100. Support layer; 1200. Wrapping layer. DETAILED DESCRIPTION

[0070] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0071] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0072] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0074] In the description of the present invention, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0075] Herein, "optionally", "optional", and "optional" mean optional, that is, any one of the two parallel schemes of "yes" or "no". If multiple "optional" items appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" item is independent of each other. In this application, descriptions such as "optionally contain", "optionally include", etc. mean "contain or not contain". "Optional component X" means that component X exists or does not exist, or means that component X is contained or not contained.

[0076] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for a broad range of quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0077] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0078] The embodiment of the present application provides an amorphous wire sensor 10 to solve the problems of large device size, poor coil consistency, large floating resistance of welding port, etc. in the conventional technology when amorphous microwire, as a special-shaped soft magnetic material, is usually electrically connected by welding process. The amorphous wire sensor 10 will be described below with reference to the accompanying drawings.

[0079] The amorphous wire sensor 10 provided in the embodiment of the present application is exemplarily shown in FIG14 , which is a schematic diagram of the structure of the amorphous wire sensor 10 provided in the embodiment of the present application. In order to more clearly illustrate the structure of the amorphous wire sensor 10 , the amorphous wire sensor 10 will be introduced below in conjunction with the accompanying drawings.

[0080] For example, please refer to FIG. 14 , which shows an amorphous wire sensor 10, including a substrate 100 and a bottom coil 200, an amorphous wire 300, an arch coil 400, a metal pad 500, an amorphous wire signal lead 600 and a coil signal lead 700 connected to the substrate 100. The bottom coil 200 is connected to the substrate 100, and a metal pad 500 is provided on the bottom coil 200. The amorphous wire 300 extends along the bottom coil 200, and the end of the amorphous wire 300 is wrapped by the metal pad 500 on the bottom coil 200 to achieve electrical connection. The arch coil 400 is bent and covered on the amorphous wire 300, and the two ends of the arch coil 400 are bent and tilted and extended to connect to the bottom coil 200. There is a support layer 1100 formed by solidifying a support material between the arch coil 400 and the bottom coil 200, and the arch coil 400 and the amorphous wire 300 are isolated by part of the support layer 1100. The amorphous wire signal lead 600 is electrically connected to the metal pad 500 . The coil signal lead 700 is electrically connected to the arch coil 400 .

[0081] In some embodiments, the amorphous wire sensor 10 further includes a wrapping layer 1200. The wrapping layer 1200 is connected to the substrate 100 and wraps and covers a portion of the bottom coil 200, a portion of the amorphous wire 300, and a portion of the arched coil 400. The metal pad 500 wrapping the end of the amorphous wire 300, the top surface of the arched coil 400, the amorphous wire signal lead 600, and the coil signal lead 700 are all exposed in the wrapping layer.

[0082] In some embodiments, the encapsulation layer 1200 is formed of a support material including non-photosensitive polyimide.

[0083] In some embodiments, the top surface of the arched coil 400 is parallel to the substrate 100 and two side portions of the top surface are curved in arcs, and the width of the top surface of the arched coil 400 is greater than the diameter of the amorphous wire 300 .

[0084] In some embodiments, the height of the support layer 1100 from the bottom coil 200 is 40 μm to 60 μm. The support layer 1100 is set at a height of 40 μm to 60 μm to fully cover the amorphous wire 300, and the arched coil 400 and the amorphous wire 300 can also be isolated by part of the support layer 1100.

[0085] In some of the embodiments, the lines of the bottom coil 200 and the extending direction of the amorphous wire 300 have an angle in the horizontal plane, wherein the angle ranges from 45° to 60°.

[0086] In some of the embodiments, the bottom layer coil 200 extends in a strip shape on the substrate 100 as a whole.

[0087] In some embodiments, the substrate 100 is a glass substrate.

[0088] An embodiment of the present application provides a method for preparing an amorphous wire sensor 10 .

[0089] It should be noted that, in this article, unless otherwise specified, each reaction step can be carried out in the order described herein, or can be carried out in a non-sequential manner. For example, other steps may be included between each reaction step, and the order of the reaction steps may also be appropriately swapped. This can be determined by the technician based on conventional knowledge and experience. Preferably, the reaction method herein is carried out sequentially.

[0090] A method for preparing an amorphous wire sensor 10 comprises the following steps:

[0091] A first metal seed layer 801 , a bottom coil 200 and a first metal sub-pad are stacked and connected on the surface of the substrate 100 , and the amorphous wire 300 is fixed on the bottom coil 200 with the two ends of the amorphous wire 300 respectively located on the first metal sub-pad.

[0092] The amorphous wire 300 and the bottom coil 200 are covered with spin-coated photoresist. After drying, exposure and development, a portion of the amorphous wire 300 fixed on the first metal sub-pad is exposed, and the outer glass layer of the exposed amorphous wire 300 is removed.

[0093] After removing the residual photoresist on the amorphous wire 300 and the underlying coil 200, a supporting material containing non-photosensitive polyimide is spin-coated on the surface of the substrate 100 and dried to obtain a covering layer 1300. Photoresist 902 is spin-coated on the surface of the covering layer 1300. After drying, exposure and development, a patterned second groove 1002 with a curved inner wall is obtained. The patterned second groove 1002 separates the covering layer 1300 into a supporting layer 1100 located on the underlying coil 200 and wrapping the amorphous wire 300, and a wrapping layer 1200 located on the substrate 100 and wrapping the underlying coil 200.

[0094] The residual photoresist 902 on the support layer 1100 and the encapsulation layer 1200 is removed, and the support layer 1100 and the encapsulation layer 1200 are baked in an oxygen-free environment to imide them.

[0095] A second metal seed layer 802, a second metal sub-pad and a plurality of arch coils 400 are sequentially prepared in a stacked manner on the surface of the imidized support layer 1100 and the wrapping layer 1200. The end of the amorphous wire 300 is wrapped between the first metal sub-pad and the second metal sub-pad. The arch coil 400 extends in a curved shape along the surface of the support layer 1200 and covers the amorphous wire 300.

[0096] It should be noted that the patterned second groove 1002 includes a plurality of second grooves, wherein two adjacent second grooves distributed along a direction perpendicular to the amorphous wire 300 are used to prepare an arch coil 400, that is, the two side portions of the arch coil 400 extend in a curved shape along the inner walls of the second grooves, and the middle portion of the arch coil 400 extends along the surface of the supporting layer 1100 between adjacent second grooves, so that the arch coil 400 as a whole is approximately in the shape of a "J".

[0097] In the present application, the supporting layer 1200 formed of the supporting material such as non-photosensitive polyimide is made to present a certain inclination toward the side wall of the patterned second groove 1002 by wet etching, so as to ensure the uniformity of subsequent photoresist coverage on the surface of the three-dimensional structure of the supporting layer 1100 and the wrapping layer 1200, and the preparation of the three-dimensional arched coil 400 can be completed without high aspect ratio columns. Compared with the traditional AZ series photoresist or SU-8 series photoresist, the imidized non-photosensitive polyimide has better physical properties, which improves the mechanical stability of the amorphous wire sensor 10. Some supporting materials such as non-photosensitive polyimide are imidized as the supporting layer 1100 instead of the sacrificial layer. Compared with the three-dimensional coil without the supporting layer 1100 in the traditional technology, the risk of coil rupture caused by deformation stress during the photoresist removal process in the traditional technology is avoided.

[0098] In some embodiments, the following steps are included when sequentially preparing the first metal seed layer 801, the bottom coil 200 and the first metal sub-pad on the surface of the substrate 100:

[0099] A first metal seed layer 801 is formed on the surface of the substrate 100 .

[0100] The photoresist 901 is spin-coated on the surface of the first metal seed layer 801 , and a patterned first groove 1001 is obtained after drying, exposure and development.

[0101] The bottom layer coil 200 and the first metal sub-pad are prepared by electroplating in the patterned first groove 1001 .

[0102] After removing the remaining photoresist 901 , the exposed first metal seed layer 801 is removed by etching.

[0103] In some embodiments, the above preparation method satisfies at least one of the following conditions:

[0104] (1) Before forming the first metal seed layer 801 on the substrate 100, the method further includes the steps of washing the substrate 100 with acetone, isopropanol and pure water in sequence and then drying the substrate 100;

[0105] (2) The first metal seed layer 801 is made of Cr and / or Cu;

[0106] (3) The preparation method of the first metal seed layer 801 includes a magnetron sputtering process, wherein the magnetron sputtering power is 600W~700W, and the sputtering rate is 4.22 Å / s~6.59Å / s;

[0107] (4) The thickness of the first metal seed layer 801 is 600Å~2000Å;

[0108] (5) When the bottom layer coil 200 and the first metal sub-pad are prepared by electroplating in the patterned first groove 1001, the electroplating solution is a CuSO4 solution, the electroplating current is 0.243A~0.3A, and the electroplating time is 480s~660s.

[0109] In some embodiments, the above preparation method satisfies at least one of the following conditions:

[0110] (1) using an HF solution to remove the outer glass layer of the exposed amorphous wire 300, wherein the concentration of the HF solution is 3% to 5%, and the etching time of the HF solution is 30 min to 35 min;

[0111] (2) The thickness of the support material containing non-photosensitive polyimide is spin-coated to 40 μm to 60 μm;

[0112] (3) When the support layer 1100 is baked at high temperature in an oxygen-free environment, the baking temperature is gradually increased from 60° C. to 350° C., and the baking time is 9 h to 15 h;

[0113] (4) The thickness of the second metal seed layer 802 is 600Å~2000Å.

[0114] In some embodiments, the supporting material containing non-photosensitive polyimide may be entirely non-photosensitive polyimide, that is, the non-photosensitive polyimide accounts for 100% of the supporting material.

[0115] In some of the embodiments, the following steps are included when sequentially preparing the stacked second metal seed layer 802, the second metal sub-pad and a plurality of arched coils 400 on the surfaces of the imidized support layer 1100 and the wrapping layer 1200:

[0116] A second metal seed layer 802 is prepared on the surface of the imidized support layer 1100 and the encapsulation layer 1200, a photoresist 903 is spin-coated on the second metal seed layer 802, and the support layer 1100 and a portion of the photoresist at the second groove adjacent to the support layer 1100 are dried, exposed, and developed to expose a portion of the second metal seed layer 802;

[0117] The second metal sub-pad is prepared by electroplating on the second metal seed layer 802 with exposed ends, the ends of the amorphous wire 300 are wrapped between the first metal sub-pad and the second metal sub-pad, and the arched coil 400 is prepared on the second metal seed layer 802 with non-exposed ends;

[0118] After removing the photoresist 903 , the exposed second metal seed layer 802 is removed by etching, so that a plurality of arched coils 400 covering the amorphous wire 300 can be obtained.

[0119] In some embodiments, the above preparation method satisfies at least one of the following conditions:

[0120] (1) The thickness of the spin-coated photoresists 901, 902, and 903 is 8 μm to 12 μm;

[0121] (2) The baking temperature for drying the photoresists 901, 902, and 903 is 100°C to 120°C, and the baking time is 180s to 300s;

[0122] (3) When exposing the photoresists 901, 902, and 903, hard contact exposure is adopted, and the exposure dose is 300mj~600mj;

[0123] (4) The developing solution for developing the photoresists 901, 902, and 903 is an alkaline solution containing a TMAH group, and the developing time is 3 minutes to 6 minutes.

[0124] (5) When removing the residual photoresist on the amorphous wire 300 and the bottom coil 200, and the residual photoresist on the surface of the first metal seed layer 801, the residual photoresist is soaked in acetone and then cleaned with isopropyl alcohol and pure water in sequence, wherein the acetone soaking time is 10 min to 20 min; when removing the residual photoresist on the supporting layer 1100, the residual photoresist is soaked in propylene glycol monomethyl ether acetate (PMA) solution and then cleaned with pure water.

[0125] For example, a specific example of the present application provides a method for preparing an amorphous wire sensor 10. The method for preparing the amorphous wire sensor 10 comprises the following steps:

[0126] Step S1: preparing a first metal seed layer 801 on the surface of the substrate 100, as shown in FIG. 2 .

[0127] Step S2, spin-coating the photoresist 901 on the surface of the first metal seed layer 801, and obtaining the patterned first groove 1001 after drying, exposure and development, as shown in FIG. 3 .

[0128] Step S3 , preparing the bottom coil 200 and the first metal sub-pad by electroplating in the patterned first groove 1001 , as shown in FIG. 4 .

[0129] Step S4 , removing the residual photoresist 901 on the surface of the first metal seed layer 801 , and etching the exposed first metal seed layer 801 to remove the exposed first metal seed layer 801 , as shown in FIG. 5 .

[0130] Step S5, fixing the amorphous wire 300 on the bottom coil 200 and positioning two ends of the amorphous wire 300 on the first metal sub-pads, as shown in FIG. 6 .

[0131] Step S6, spin-coating photoresist to cover the amorphous wire 300 and the bottom coil 200, and after drying, exposure and development, a portion of the amorphous wire 300 fixed on the first metal sub-pad is exposed.

[0132] Step S7, removing the outer glass layer of the exposed amorphous wire 300.

[0133] Step S8: removing the residual photoresist.

[0134] Step S9, spin-coating a support material containing non-photosensitive polyimide, and drying to obtain a covering layer 1300, as shown in FIG7. Spin-coating a photoresist 902 on the surface of the covering layer 1300, drying, exposing, and developing to obtain a patterned second groove 1002 with a curved inner wall, and the patterned second groove 1002 separates the covering layer 1300 to form a supporting layer 1100 located on the bottom coil 200 and wrapping the amorphous wire 300 and a wrapping layer 1200 located on the substrate 100 and wrapping the bottom coil 200, as shown in FIG8.

[0135] Step S10, removing the residual photoresist 902 on the support layer 1100 and the encapsulation layer 1200, as shown in FIG. 9 .

[0136] Step S11 , baking the support layer 1100 and the wrapping layer 1200 at high temperature in an oxygen-free environment to imide them.

[0137] Step S12: preparing a second metal seed layer 802 on the surfaces of the imidized support layer 1100 and the encapsulation layer 1200, as shown in FIG. 10 .

[0138] Step S13, spin-coating photoresist 903 on the second metal seed layer 802, drying, exposing and developing the portion of the photoresist on the support layer 1100 and the second groove adjacent to the support layer 1100 to expose a portion of the second metal seed layer, as shown in FIG. 11 .

[0139] Step S14, electroplating is performed on the second metal seed layer 802 with the end exposed to prepare a second metal sub-pad and a plurality of arch coils 400, the end of the amorphous wire 300 is wrapped between the first metal sub-pad and the second metal sub-pad, and the arch coil 400 is prepared on the second metal seed layer that is not exposed at the end, as shown in Figure 12.

[0140] Step S15 , removing the photoresist 903 to expose the second metal seed layer 802 , and using an etching solution to remove the exposed second metal seed layer 802 , as shown in FIG. 13 .

[0141] Step S16: Slice bonding.

[0142] In the preparation method of the present application, a support layer 1100 formed by a support material containing non-photosensitive polyimide is used as a support for the three-dimensional arch coil 400. Compared with traditional photoresists, support materials containing non-photosensitive polyimide have higher viscosity. During the development process, thicker or too viscous support materials containing non-photosensitive polyimide will slow down the diffusion rate of the developer, making it easier for the support layer 1100 to form an inclined surface during the development process. By controlling the development time of the support material containing non-photosensitive polyimide, an inclined surface is formed on its side wall to prepare the arch coil 400. In the subsequent step of spin coating the photoresist, the photoresist will be evenly distributed on the inclined surface, and the preparation of the three-dimensional arch coil 400 can be completed by one-time electroplating. The preparation process is simple and convenient. The imidized support layer 1100 has excellent mechanical properties. As a support for the arch coil 400, the stability of the three-dimensional coil can be significantly improved. Compared with the three-dimensional micro-coil prepared by the traditional MEMS process, the arch coil 400 prepared by the present invention does not need to undergo long-term electroplating to form a column structure with a high aspect ratio. The present application is a column-free structure, which can reduce the process cost and complexity while also improving the production efficiency and quality of the device.

[0143] In some embodiments, the above preparation method also satisfies at least one of the following conditions:

[0144] In some of the embodiments, before preparing the first metal seed layer 801 on the substrate 100 in step S1, the step of washing the substrate 100 with acetone, isopropyl alcohol and pure water in sequence and then drying the substrate 100 is also included.

[0145] In some embodiments, in step S1 , the first metal seed layer 801 is made of Cr and / or Cu.

[0146] In some of the embodiments, in step S1, the preparation method of the first metal seed layer 801 includes a magnetron sputtering process, wherein the magnetron sputtering power is 600W~700W, and the sputtering rate is 4.22 Å / s~6.59Å / s.

[0147] In some embodiments, in step S1 , the thickness of the first metal seed layer 801 is 600Å-2000Å.

[0148] In some embodiments, in step S2 , the thickness of the photoresist 901 spin-coated on the surface of the first metal seed layer 801 is 8 μm-12 μm.

[0149] In some embodiments, in step S2, the baking temperature during drying is 100° C. to 120° C., and the baking time is 180 s to 300 s.

[0150] In some of the embodiments, in step S2, hard contact exposure is used for exposure, and the exposure dose is 300mj~600mj.

[0151] In some of the embodiments, in step S2, during development, the developing solution is an alkaline solution containing TMAH groups, and the developing time is 3 min to 6 min.

[0152] In some of the embodiments, in step S3, when the bottom coil 200 and the first metal sub-pad are prepared by electroplating in the patterned first groove 1001, the electroplating solution is a CuSO4 solution, the electroplating current is 0.243A~0.3A, and the electroplating time is 480s~660s.

[0153] In some of the embodiments, in step S4, acetone is used to remove the residual photoresist, wherein the acetone immersion time is 10 min to 20 min.

[0154] In some of the embodiments, in step S6, the thickness of the spin-coated photoresist is 8 μm-12 μm.

[0155] In some embodiments, in step S6, the baking temperature during drying is 100° C. to 120° C., and the baking time is 180 s to 300 s.

[0156] In some of the embodiments, in step S6, hard contact exposure is used for exposure, and the exposure dose is 300mj-600mj.

[0157] In some of the embodiments, in step S6, during development, the developing solution is an alkaline solution containing TMAH groups, and the developing time is 3 min to 6 min.

[0158] In some of the embodiments, in step S7, an HF solution is used to remove the outer glass of the exposed amorphous wire 300, wherein the concentration of the HF solution is 3% to 5%, and the etching time of the HF solution is 30 min to 35 min.

[0159] In some of the embodiments, in step S8, acetone is used to remove the residual photoresist, and isopropyl alcohol and pure water are used for cleaning, wherein the acetone immersion time is 10 min to 20 min.

[0160] In some embodiments, in step S9 , the thickness of the support material containing non-photosensitive polyimide is spin-coated to be 40 μm to 60 μm.

[0161] In some of the embodiments, in step S9 , the thickness of the photoresist 902 spin-coated on the surface of the support layer 1100 is 8 μm-12 μm.

[0162] In some embodiments, in step S9, the baking temperature during drying is 100° C. to 120° C., and the baking time is 180 s to 300 s.

[0163] In some of the embodiments, in step S9, hard contact exposure is used for exposure, and the exposure dose is 300mj-600mj.

[0164] In some embodiments, in step S9, during development, the developing solution is an alkaline solution containing TMAH groups, and the developing time is 3 min to 6 min.

[0165] In some of the embodiments, in step S10 , a propylene glycol monomethyl ether acetate (PMA) solution is used to remove the residual photoresist on the support layer 1100 .

[0166] In some of the embodiments, in step S11, when the support layer 1100 is baked at high temperature in an oxygen-free environment, the baking temperature is gradually increased from 60° C. to 350° C., and the baking time is 9 h to 15 h.

[0167] In some of the embodiments, in step S12, a second metal seed layer 802 is prepared on the surface of the support layer 1100 by a magnetron sputtering process, wherein the magnetron sputtering power is 600W~700W, and the sputtering rate is 4.22 Å / s~6.59Å / s.

[0168] In some embodiments, in step S12, the thickness of the second metal seed layer 802 is 600Å-2000Å.

[0169] In some embodiments, in step S13 , the thickness of the photoresist 903 spin-coated on the second metal seed layer 802 is 8 μm-12 μm.

[0170] In some embodiments, in step S13, the baking temperature during drying is 100° C. to 120° C., and the baking time is 180 s to 300 s.

[0171] In some of the embodiments, in step S13, hard contact exposure is used for exposure, and the exposure dose is 300mj-600mj.

[0172] In some embodiments, in step S13, during development, the developing solution is an alkaline solution containing TMAH groups, and the developing time is 3 min to 6 min.

[0173] In some of the embodiments, in step S14, when the second metal sub-pad and the arch coil 400 are prepared by electroplating on the second metal seed layer 802 with the exposed end, the plating solution is a CuSO4 solution, the plating current is 0.243A~0.3A, and the plating time is 480s~660s.

[0174] In some of the embodiments, in step S15, acetone is used to remove the photoresist 903 to expose the second metal seed layer 802, and the surface of the second metal seed layer 802 is cleaned with isopropyl alcohol and pure water, wherein the acetone immersion time is 10 min to 20 min.

[0175] In some of the embodiments, the photoresists 901, 902, and 903 in the present application may be positive photoresists, such as model AZP4620 photoresists.

[0176] The preparation method of the amorphous wire sensor 10 of the present invention utilizes the MEMS process to realize the combination of wire and wafer. Under the premise of ensuring performance and consistency, when a supporting material containing non-photosensitive polyimide is used to form the supporting layer 1100, the preparation process of the three-dimensional micro-coil can be simplified, the coil stability can be improved, and the integration of the arch coil 400 and the amorphous wire 300 can be completed, thereby realizing the batch production of miniaturized amorphous wire sensors.

[0177] Example 1

[0178] This embodiment provides a micro amorphous wire sensor having an arched coil 400 .

[0179] The micro amorphous wire sensor of this embodiment is prepared by the following preparation method.

[0180] A method for preparing a micro amorphous wire sensor comprises the following steps:

[0181] Step S1, using acetone, isopropyl alcohol and pure water to clean the glass substrate 100 in sequence and then drying it for standby use, as shown in FIG1 .

[0182] Step S2, using a magnetron sputtering process to prepare a first metal seed layer 801 on the surface of the glass substrate 100, the first metal seed layer 801 is a copper seed layer, the sputtering process parameters are: sputtering power is 600W, sputtering rate is 6.59 Å / s, and the thickness of the first metal seed layer 801 is 2000Å, as shown in Figure 2.

[0183] Step S3, spin 10μmAZP4620 photoresist on the surface of the first metal seed layer 801, dry it at 110℃ for 200s, use hard contact exposure with an exposure dose of 300mj~600mj, and use an alkaline solution containing TMAH group to develop for 5min to obtain a patterned first groove 1001, as shown in Figure 3.

[0184] Step S4: Use CuSO4 solution to electroplate the bottom coil 200 and the first metal sub-pad in the patterned first groove 1001, with the electroplating current of 0.243A and the electroplating time of 500s, as shown in Figure 4. The first metal sub-pad is not shown in Figure 4.

[0185] Step S5, using acetone to soak for 10 minutes to remove the residual AZP4620 photoresist 901, after exposing the metal seed layer, using copper etching solution to etch to remove the exposed part of the first metal seed layer 801, as shown in FIG. 5 .

[0186] Step S6, fix the amorphous wire 300 with a diameter of 30 μm on the bottom coil 200, and the two ends of the amorphous wire 300 are respectively located on the first metal sub-pads, as shown in Figure 6. The amorphous wire 300 shown in Figure 6 is a radial cross-sectional view thereof.

[0187] Step S7, spin-coat 10 μm thick AZP4620 photoresist to cover the amorphous wire 300 and the bottom coil 200, dry at 110°C for 200 seconds, use hard contact exposure with an exposure dose of 500 mj, and develop with an alkaline solution containing TMAH for 5 minutes to expose the amorphous wire 300 fixed on the first metal sub-pad.

[0188] Step S8, using a 4% HF solution to etch the end of the amorphous wire 300 for 30 minutes to remove the outer glass layer of the exposed amorphous wire 300.

[0189] Step S9: Use acetone to soak for 10 minutes to remove the residual AZP4620 photoresist, and use isopropyl alcohol and pure water to clean.

[0190] Step S10, spin-coat a non-photosensitive polyimide with a thickness of 50 μm on the glass substrate 100, and dry to obtain a covering layer 1300, as shown in FIG7. Spin-coat a 10 μm thick AZP4620 photoresist 902 on the surface of the covering layer 1300, dry at 110°C for 200s, use hard contact exposure, the exposure dose is 500mj, and use an alkaline solution containing a TMAH group to develop for 5min to obtain a patterned second groove 1002 with a curved inner wall. The patterned second groove 1002 separates the covering layer 1300 to form a supporting layer 1100 located on the bottom coil 200 and wrapping the amorphous wire 300 and a wrapping layer 1200 located on the substrate 100 and wrapping the bottom coil 200, as shown in FIG8.

[0191] Step S11 : using propylene glycol monomethyl ether acetate (PMA) solution to remove the residual photoresist 902 on the support layer 1100 and the encapsulation layer 1200 , as shown in FIG. 9 .

[0192] Step S12: baking the support layer 1100 and the wrapping layer 1200 at high temperature in an oxygen-free environment to imide them.

[0193] Step S13: Use a magnetron sputtering process to prepare a second metal seed layer 802 on the surface of the support layer 1100 and the encapsulating layer 1200. The second metal seed layer 802 is a copper seed layer. The sputtering process parameters are: sputtering power is 600 W, sputtering rate is 6.59 Å / s, and the thickness of the second metal seed layer 802 is 500 Å, as shown in Figure 10.

[0194] Step S14, spin-coat AZP4620 photoresist 903 with a thickness of 10 μm on the second metal seed layer 802, dry it at a temperature of 110°C for 200 seconds, use hard contact exposure with an exposure dose of 500 mj, and use an alkaline solution containing a TMAH group for 5 minutes to develop, remove part of the photoresist at the second groove adjacent to the supporting layer 1100 and the supporting layer 110, so as to expose part of the second metal seed layer, as shown in Figure 11.

[0195] Step S15, using CuSO4 solution to electroplate on the second metal seed layer 802 with exposed ends to prepare a second metal sub-pad and a plurality of arched coils 400, the electroplating current is 0.3A, the electroplating time is 480s, the end of the amorphous wire 300 is wrapped between the first metal sub-pad and the second metal sub-pad, and the arched coil 400 is prepared on the second metal seed layer that is not exposed at the end, as shown in Figure 12. The first metal sub-pad and the second metal sub-pad are not shown in the drawings.

[0196] Step S16, using acetone to soak for 10 minutes to remove the photoresist 903 and expose the second metal seed layer 802, and then using copper etching solution to etch and remove the exposed second metal seed layer 802, as shown in FIG. 13 .

[0197] Step S17, slice and bond according to the preset size requirements. The amorphous wire sensor 10 is prepared, as shown in FIG14, the amorphous wire 300 extends along the bottom coil 200 and the end of the amorphous wire 300 is wrapped by the metal pad 500 on the bottom coil 200 to achieve electrical connection, the arched coil 400 is bent and covered on the amorphous wire 300, and the two ends of the arched coil 400 are bent and tilted and extended to connect to the bottom coil 200, and there is a support layer 1100 formed by solidifying the support material between the arched coil 400 and the bottom coil 200, and the arched coil 400 and the amorphous wire 300 are isolated by the support layer 1100. The actual picture of the amorphous wire sensor 10 is shown in FIG15.

[0198] To sum up, the amorphous wire sensor 10 of the present invention overcomes the shortcomings of traditional amorphous wire 300GMI magnetic sensors such as low production efficiency, poor device consistency, and large size. It uses electroplating technology based on MEMS technology to achieve the electrical connection of the amorphous wire 300 and the preparation of a three-dimensional coil. It uses a supporting material containing non-photosensitive polyimide to form a supporting layer 1100 to enhance the stability of the coil, while optimizing the structure and preparation process of the three-dimensional coil, reducing production costs and process complexity, so that the amorphous wire sensor can reduce the volume of the amorphous wire sensor while ensuring device consistency, and improve the production efficiency of the sensor, thereby achieving the purpose of mass production of miniature amorphous wire sensors.

[0199] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0200] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0201] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing an amorphous wire sensor, characterized in that: The following steps are included: Prepare a first metal seed layer, a bottom coil and a first metal sub-pad connected in a stacked manner on the surface of the substrate, fix the amorphous wire on the bottom coil and place two ends of the amorphous wire on the first metal sub-pad respectively; Spin-coating photoresist to cover the amorphous wire and the bottom coil, and after drying, exposure, and development, exposing a portion of the amorphous wire fixed on the first metal sub-pad, and removing the outer glass layer of the exposed amorphous wire; After removing the residual photoresist on the amorphous wire and the bottom coil, a support material containing non-photosensitive polyimide is spin-coated on the surface of the substrate, and a covering layer is obtained by drying. A photoresist is spin-coated on the surface of the covering layer, and a second patterned groove with a curved inner wall is obtained through drying, exposure, and development. The second patterned groove separates the covering layer into a support layer located on the bottom coil and wrapping the amorphous wire, and a wrapping layer located on the substrate and wrapping the bottom coil; Removing the residual photoresist on the support layer and the encapsulation layer, and baking the support layer and the encapsulation layer in an oxygen-free environment to imide them; A second metal seed layer, a second metal sub-pad and a plurality of arch coils are sequentially stacked and connected on the surfaces of the support layer and the wrapping layer, an end of the amorphous wire is wrapped between the first metal sub-pad and the second metal sub-pad, and the arch coil extends in a curved shape along the surface of the support layer and covers the amorphous wire.

2. The preparation method according to claim 1, characterized in that: When a first metal seed layer, a bottom layer coil and a first metal sub-pad are sequentially prepared on the surface of a substrate, the following steps are included: Prepare the first metal seed layer on the surface of the substrate; Spin-coating photoresist on the surface of the first metal seed layer, and obtaining a patterned first groove after drying, exposure and development; Electroplating the bottom layer coil and the first metal sub-pad in the patterned first groove; After removing the residual photoresist, the exposed first metal seed layer is removed by etching.

3. The preparation method according to claim 2, characterized in that: The preparation method also satisfies at least one of the following conditions: (1) Before preparing the first metal seed layer on the substrate, the method further comprises the steps of washing the substrate with acetone, isopropanol and pure water in sequence and then drying the substrate; (2) The first metal seed layer is made of Cr and / or Cu; (3) The preparation method of the first metal seed layer includes a magnetron sputtering process, wherein the magnetron sputtering power is 600W~700W, and the sputtering rate is 4.22 Å / s~6.59Å / s; (4) The thickness of the first metal seed layer is 600Å~2000Å; (5) When the bottom layer coil and the first metal sub-pad are prepared by electroplating in the patterned first groove, the electroplating solution is a CuSO4 solution, the electroplating current is 0.243A~0.3A, and the electroplating time is 480s~660s.

4. The preparation method according to claim 1, characterized in that: The preparation method also satisfies at least one of the following conditions: (1) using an HF solution to remove the exposed outer glass layer of the amorphous wire, wherein the concentration of the HF solution is 3% to 5%, and the HF solution etching time is 30 min to 35 min; (2) The thickness of the spin-coated support material is 40 μm to 60 μm; (3) When the support layer is baked at high temperature in an oxygen-free environment, the baking temperature is gradually increased from 60°C to 350°C, and the baking time is 9h~15h; (4) The thickness of the second metal seed layer is 600Å~2000Å.

5. The preparation method according to claim 1, characterized in that: When a second metal seed layer, a second metal sub-pad and a plurality of arched coils are sequentially prepared in a stacked manner on the surfaces of the support layer and the wrapping layer, the following steps are included: Preparing a second metal seed layer on the surface of the support layer and the wrapping layer, spin-coating a photoresist on the second metal seed layer, and drying, exposing, and developing a portion of the photoresist at the support layer and the second groove adjacent to the support layer to expose a portion of the second metal seed layer; The second metal sub-pad is prepared by electroplating on the second metal seed layer with exposed ends, the end of the amorphous wire is wrapped between the first metal sub-pad and the second metal sub-pad, and the arched coil is prepared on the second metal seed layer with non-exposed ends; After removing the photoresist, the exposed second metal seed layer is removed by etching.

6. The preparation method according to claim 5, characterized in that: The preparation method also satisfies at least one of the following conditions: (1) preparing the second metal seed layer on the surface of the imidized support layer by a magnetron sputtering process, wherein the magnetron sputtering power is 600 W to 700 W and the sputtering rate is 4.22 Å / s to 6.59 Å / s; (2) When the second metal sub-pad and the arch coil are prepared by electroplating on the exposed second metal seed layer at the end, the electroplating solution is a CuSO4 solution, the electroplating current is 0.243A~0.3A, and the electroplating time is 480s~660s.

7. The preparation method according to any one of claims 1, 3 and 6, characterized in that: The preparation method also satisfies at least one of the following conditions: (1) The thickness of the spin-coated photoresist is 8μm~12μm; (2) The baking temperature for drying the photoresist is 100°C~120°C, and the baking time is 180s~300s; (3) Hard contact exposure is used for photoresist exposure, and the exposure dose is 300mj~600mj; (4) The developing solution for developing the photoresist is an alkaline solution containing TMAH group, and the developing time is 3min~6min; (5) When removing the residual photoresist on the amorphous wire and the bottom coil, and the residual photoresist on the surface of the first metal seed layer, the residual photoresist is soaked in acetone and then washed with isopropyl alcohol and pure water in sequence, wherein the acetone soaking time is 10 min to 20 min; when removing the residual photoresist on the supporting layer, the residual photoresist is soaked in propylene glycol monomethyl ether acetate solution and then washed with pure water.

8. An amorphous wire sensor, characterized in that: It includes a substrate and a bottom coil, an amorphous wire, an arch coil, a metal pad, an amorphous wire signal lead and a coil signal lead connected to the substrate; wherein the bottom coil is connected to the substrate, the metal pad is arranged on the bottom coil, the amorphous wire extends along the bottom coil and the end of the amorphous wire is wrapped by the metal pad on the bottom coil to achieve electrical connection, the arch coil is bent and covers the amorphous wire, the two ends of the arch coil are bent and inclined and extend to the bottom coil, the two ends of the arch coil are respectively connected to the bottom coil, a supporting layer formed by solidifying a supporting material is provided between the arch coil and the bottom coil, the arch coil and the amorphous wire are isolated from each other by part of the supporting layer, the height of the supporting layer from the bottom coil is greater than the diameter of the amorphous wire, the amorphous wire signal lead is electrically connected to the metal pad, and the coil signal lead is electrically connected to the arch coil.

9. The amorphous wire sensor according to claim 8, characterized in that: The amorphous wire sensor also includes a wrapping layer, which is connected to the substrate and wraps and covers part of the bottom coil, part of the amorphous wire and part of the arch coil, wherein the metal pad wrapping the end of the amorphous wire, the top surface of the arch coil, the amorphous wire signal lead and the coil signal lead are all exposed in the wrapping layer.

10. The amorphous wire sensor according to claim 9, characterized in that: The wrapping layer is formed of a supporting material containing non-photosensitive polyimide.

11. The amorphous wire sensor according to any one of claims 8 to 10, characterized in that: The top surface of the arched coil is parallel to the substrate and two side portions of the top surface are respectively curved in an arc shape, and the width of the top surface of the arched coil is greater than the diameter of the amorphous wire; And / or, the height between the support layer and the bottom coil is 40 μm-60 μm.

12. The amorphous wire sensor according to any one of claims 8 to 10, characterized in that: The lines of the bottom coil and the extension direction of the amorphous wire have an angle ranging from 45° to 60° in the horizontal plane; and / or, the bottom layer coil as a whole extends in a strip shape on the substrate; And / or, the substrate is a glass substrate.

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