A flexible hall angle sensor and angle detection system

Abstract

The application provides a flexible Hall angle sensor and an angle detection system, wherein the flexible Hall angle sensor comprises a flexible substrate and a die fixed to the flexible substrate, and the flexible substrate is provided with a conductive circuit electrically connected with the die; the die is provided with a Hall disc for converting a magnetic field signal into a Hall voltage signal and a circuit unit for supporting the working of the Hall disc, and the Hall disc is electrically connected with the conductive circuit through the circuit unit. By arranging the die on the flexible substrate and arranging the Hall disc for detecting the Hall voltage signal and the circuit unit for supporting the Hall disc on the die, the single chip die can realize the sensing of the magnetic induction intensity, the conductive circuit electrically connected with the die can be deformed with the bending or stretching of the flexible substrate and keep the conductive performance, and the application has the advantages of good flexibility, high reliability, mechanical performance, electrical performance and cost.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of sensors, in particular to a flexible Hall angle sensor and an angle detection system. BACKGROUND

[0002] Hall sensors are widely used in automotive and consumer electronics applications to accurately detect position or monitor current. At present, silicon CMOS-based Hall sensors, as the mainstream Hall detection scheme in the market, are applied to most related scenarios due to their long market development history and low production cost. At present, in many emerging application fields, such as wearable electronic devices, electronic skin, highly integrated robot arms, prostheses and the like, thin and flexible sensor devices are needed. For these application categories, flexibility not only provides additional mechanical properties at the operation level, but also makes the sensor capable of being laid out in a three-dimensional structure with limited volume, which brings opportunities to effectively add intelligent sensing functions without changing the current complex mechanical structure.

[0003] Traditional Hall sensors often encounter various problems when used in such new fields. For example, in order to make the traditional Hall sensor have a bendable performance, the existing scheme usually adopts a scheme of arranging a packaged Hall sensor chip on a flexible printed circuit board (FPC). However, this scheme has the problems of high cost, poor bending resistance and poor stability. Therefore, the industry urgently needs a flexible Hall sensor that can have good stretchable or bendable performance while having the advantages of high reliability, mechanical performance, electrical performance and cost of hard silicon CMOS devices. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a flexible Hall angle sensor, comprising a flexible substrate and a die fixed to the flexible substrate, the flexible substrate being provided with a conductive circuit electrically connected with the die; the die is provided with a Hall disc for converting a magnetic field signal into a Hall voltage signal and a circuit unit for supporting the working of the Hall disc, the Hall disc being electrically connected with the conductive circuit through the circuit unit, the conductive circuit being used for supplying power to the Hall disc and transmitting the Hall voltage signal, and the conductive circuit being capable of deforming and maintaining the conductive performance with the bending or stretching of the flexible substrate.

[0005] The flexible Hall angle sensor according to the first aspect of the present application has at least the following beneficial effects:

[0006] The flexible Hall angle sensor of the first aspect of the present application is provided with a crystal grain on a flexible substrate, and a Hall disc for detecting a Hall voltage signal and a circuit unit for supporting the Hall disc are directly arranged on the crystal grain, so that a single chip crystal grain can realize the sensing of magnetic induction intensity, and the hard crystal grain prepared based on the CMOS process can maintain its high reliability and advantages in cost and electrical performance. In addition, the conductive circuit and the circuit unit on the crystal grain are electrically connected, and the flexible Hall angle sensor can maintain performance while obtaining better stretchability or foldability. Therefore, the flexible sensor of the first aspect of the present application has better stretchability or foldability, is more lightweight, and has high reliability, mechanical performance advantages, electrical performance advantages and cost advantages.

[0007] In an embodiment, a plurality of crystal grains are arranged in an array on the flexible substrate to form an island-bridge arrangement structure with the flexible substrate; wherein the array of the crystal grains is obtained based on finite element analysis of the island-bridge arrangement structure, so as to ensure that the flexible Hall angle sensor has a reasonable strain distribution under bending conditions and improves the allowable bending curvature thereof.

[0008] In an embodiment, the Hall disc includes a functional layer and a substrate layer, the functional layer is provided with a via hole, and the circuit unit is electrically connected to the Hall disc through the via hole to provide a bias current for the Hall disc or obtain a Hall voltage signal from the Hall disc, and the functional layer is used to generate a Hall voltage signal at the position of the via hole based on the Hall effect.

[0009] In an embodiment, the functional layer adopts one or more of an N epitaxial layer, an N deep buried layer and a low-voltage N well; the substrate layer adopts one of a high-voltage P well, a low-voltage P well, a P-type substrate and a P deep buried layer, and the via hole adopts an N-type material as a direct connection path of the conductive circuit.

[0010] In an embodiment, the connection between the conductive circuit and the die is implemented by one or more of the following: bonding metal wires, soldering, form-free conductive glue, conductive silver paste, and anisotropic conductive glue; in the case of using bonding metal wires to connect the conductive circuit and the die, the die is directly or indirectly attached to the flexible substrate through the substrate layer side; in the case of using one or more of soldering, form-free conductive glue, conductive silver paste, and anisotropic conductive glue to connect the conductive circuit and the die, the die is directly or indirectly attached to the flexible substrate through the via side; the material of the flexible substrate includes one or more of the following: PI, PDMS, TPU, SU8, photoresist, PET, PMMA, PVA, PEN, paper sheet, and textile material; the material of the conductive circuit is adapted to the tensile property of the material of the flexible substrate, and includes one or more of the following: gold, silver, copper, iron, alloy, stretchable conductive silver paste, PEDOT: PSS, or gallium-indium alloy; in addition, to adapt to the tensile property of the material of the flexible substrate, the conductive circuit is correspondingly implemented in an island-bridge structure to protect the conductive path under large stretching conditions.

[0011] In an embodiment, the conductive circuit and the die are connected by bonding metal wires, and the flexible Hall angle sensor further includes a cover layer, the bonding metal wires connect the conductive circuit and the circuit unit, and the cover layer covers the flexible substrate, the die, and the bonding metal wires at the same time, the cover layer is used to protect the bonding metal wires and disperse the stress received by the die in the case of deformation of the flexible Hall angle sensor.

[0012] In an embodiment, the flexible Hall angle sensor of the present application further includes an electromagnetic shielding structure, the electromagnetic shielding structure includes one or more of the following combinations: a cover layer and a flexible substrate diffused with conductive particle materials, and a stretchable conductive fabric or conductive sponge wrapped around the periphery of the flexible Hall angle sensor; the cover layer and the flexible substrate are insulated by pre-polymerization to avoid short circuit; in addition, the flexible Hall angle sensor is further provided with a reinforcement structure for increasing the Young's modulus of a partial region to improve the durability, the reinforcement structure is implemented by one or more of the following: an island-bridge structure formed after local hardening treatment of the flexible substrate, a layered structure, a porous structure, or a foam structure provided on the cover layer through topology optimization, and a combination thereof.

[0013] In an embodiment, the circuit unit includes an amplifier circuit, a reference power supply electrically connected to the amplifier circuit, and an output buffer circuit, the output buffer circuit is electrically connected to the conductive circuit; the amplifier circuit is electrically connected to the Hall disc to obtain and amplify the Hall voltage signal output by the Hall disc, and the output buffer circuit is used to obtain and optimize the Hall voltage signal from the amplifier circuit and then output to the conductive circuit.

[0014] In an embodiment, the circuit unit further comprises a bias current source disposed between the conductive line and the Hall disc, the bias current source being provided with a PTAT current circuit, the bias current source adjusting the size of the bias current according to temperature based on the PTAT current circuit to provide temperature compensation for the Hall disc and the amplifier circuit while achieving power supply.

[0015] According to the second aspect of the present application, the angle detection system comprises the flexible Hall angle sensor, the outer ring, the magnet, the inner rotating shaft and the data acquisition module, the flexible Hall angle sensor is bent and attached to the outer ring, the inner rotating shaft is arranged in the outer ring, the magnet is arranged on the inner rotating shaft corresponding to the flexible Hall angle sensor, and the data acquisition module is electrically connected to the flexible Hall angle sensor; when the inner rotating shaft rotates and the angle changes, the magnet is displaced to cause the relative position of the crystal grain on the flexible Hall angle sensor to change, so that the Hall voltage signal of the crystal grain changes correspondingly, and the data acquisition module is used for collecting and analyzing the Hall voltage signal of the crystal grain to obtain the angle information of the inner rotating shaft.

[0016] According to the angle detection system of the second aspect of the present application, at least the following beneficial effects are achieved:

[0017] The angle detection system of the second aspect of the present application comprises the flexible Hall angle sensor of the first aspect of the present application, and the inventive concept is the same as that of the first aspect of the present application, so it has all the technical improvements and technical effects of the first aspect of the present application, which will not be repeated here. In addition, since the angle detection system uses the flexible Hall angle sensor of the first aspect of the present application, it has the ability to be bent or stretched, and the shape of the outer ring can be designed more flexibly based on the actual situation, that is, the system can adapt to different use scenarios and flexibly adapt to different shaped components for installation. At the same time, since multiple detection-capable crystal grains can be integrated onto the same flexible Hall angle sensor and arranged more reasonably, the detection dimension can be expanded while achieving higher detection accuracy.

[0018] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and achieved by the specific embodiments particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings are intended to provide a further understanding of the technical solutions of the present application and constitute a part of the specification, and together with the embodiments of the present application, are used to explain the technical solutions of the present application, and do not constitute a limitation on the technical solutions of the present application.

[0020] Figure 1 is a schematic diagram of a flexible Hall angle sensor provided by an embodiment of the present application;

[0021] Figure 2 is a schematic diagram of a circuit framework of a die provided by an embodiment of the present application;

[0022] Figure 3 is a schematic diagram of a flexible Hall angle sensor being tested in a specific example of the present application;

[0023] Figure 4 is a schematic diagram of a flexible Hall angle sensor being tested in a specific example of the present application; Figure 3 is a test result diagram of a flexible Hall angle sensor in a specific example of the present application;

[0024] Figure 5 is a schematic diagram of a flexible Hall angle sensor using multiple dies arranged in a specific example of the present application;

[0025] Figure 6 is a schematic diagram of a structure of a Hall plate in an embodiment of the present application;

[0026] Figure 7 is a schematic diagram of a cross section of a die mounted on a flexible substrate in an embodiment of the present application;

[0027] Figure 8 is a schematic diagram of an angle detection system provided by an embodiment of the present application.

[0028] Figure 9 is a schematic diagram of an angle detection system being tested in a specific example of the present application; Figure 8 is a test result diagram of an angle detection system in a specific example of the present application.

[0029] Reference signs: flexible substrate 100, die 101, conductive circuit 102, bonding metal wire 103, cover layer 104, Hall plate 200, amplifier circuit 201, reference power supply 202, output buffer circuit 203, bias current source 204, test magnet 300, test object 301, bidirectional displacement table 302, test power supply 303, oscilloscope 304, functional layer 400, substrate layer 401, via hole 402, flexible Hall angle sensor 500, outer ring 501, magnet 502, inner rotating shaft 503, data acquisition module 504. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the present disclosure, and these embodiments are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0031] It should be noted that in the description of the present disclosure, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first" and "second" can be explicitly or implicitly included one or more features.

[0032] It should also be noted that if the embodiments of the present disclosure involve directional indications, such as up, down, left, right, front, back, etc., the directional indications are only used to explain the relative position relationship, motion condition, etc. between the components in a certain posture (such as shown in the drawings), and if the certain posture changes, the directional indications should also change accordingly.

[0033] In addition, unless otherwise explicitly specified and limited, the term "connection / connected" should be understood broadly, for example, it can be a fixed connection or a movable connection, or a detachable connection or a non-detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements.

[0034] Finally, in the description of the present disclosure, the description of the terms "one embodiment / implementation", "another embodiment / implementation", or "some embodiments / implementation" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least two embodiments or implementations of the present disclosure. In the present disclosure, the illustrative description of the above terms does not necessarily refer to the same embodiment or implementation. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or implementations in a suitable manner.

[0035] The embodiments of the present application will be further described below with reference to the accompanying drawings.

[0036] As Figure 1 shown, Figure 1 is a schematic diagram of a flexible Hall angle sensor according to an embodiment of the present application, and in Figure 1 the example, the flexible Hall angle sensor according to the embodiment of the present application includes but is not limited to: a flexible substrate 100 and a die 101 fixed to the flexible substrate 100, and the flexible substrate 100 is provided with a conductive circuit 102 electrically connected to the die 101.

[0037] It can be understood that the conductive circuit 102 is used to supply power to the Hall disc 200 and transmit the Hall voltage signal, and the conductive circuit 102 can be deformed with the bending or stretching of the flexible substrate 100 and maintain the conductive performance.

[0038] Referring to Figure 2, Figure 2 is a schematic diagram of a circuit framework of the crystal grain 101 provided by an embodiment of the present application, and Figure 2 In the example, the crystal grain 101 is provided with a Hall disc 200 for converting a magnetic field signal into a Hall voltage signal and a circuit unit for supporting the working of the Hall disc 200.

[0039] Specifically, the Hall disc 200 is electrically connected to the conductive circuit 102 through the circuit unit, that is, the conductive circuit 102 has the functions of supplying power to the crystal grain 101 and transmitting the Hall voltage signal.

[0040] In an embodiment, the crystal grain 101 is an ASIC chip crystal grain 101 prepared by a CMOS process, and the Hall disc 200 for realizing the Hall sensing function and the circuit unit for supporting the working of the Hall disc 200 are both arranged on the single crystal grain 101, so that the single crystal grain 101 can realize the sensing of the magnetic induction intensity.

[0041] It can be understood that, by arranging the crystal grain 101 on the flexible substrate 100 and arranging the Hall disc 200 for realizing the Hall voltage signal detection and the circuit unit for supporting the Hall disc 200 on the crystal grain 101, the single chip crystal grain 101 can realize the sensing of the magnetic induction intensity, and the hard crystal grain 101 prepared based on the CMOS process can maintain its high reliability and advantages in cost and electrical performance. In addition, the conductive circuit 102 that can deform with the bending or stretching of the flexible substrate 100 and maintain the conductive performance is electrically connected to the circuit unit on the crystal grain 101, and the flexible Hall angle sensor can obtain better stretchable or bendable capability while maintaining the performance. Therefore, the flexible sensor of the first aspect embodiment of the present application has better stretchable or bendable performance and is more lightweight, and can also have high reliability, mechanical performance advantages, electrical performance advantages and cost advantages.

[0042] In an embodiment, a plurality of crystal grains 101 are arranged, and the plurality of crystal grains 101 are arranged in an array form on the flexible substrate 100 and form an island-bridge type arrangement structure together with the flexible substrate 100.

[0043] The array form of the crystal grain 101 is obtained based on a finite element analysis method for analyzing the island-bridge type arrangement structure, so as to ensure that the flexible Hall angle sensor has a reasonable strain distribution under bending conditions and improve the allowable bending curvature thereof.

[0044] Specifically, the silicon grains 101 segmented into small pieces are mounted on the flexible substrate 100, and a three-dimensional model of the silicon grains 101 and the PI, PDMS, and other substrate materials with large differences in Young's modulus and the pad connection, overall bending, stretching, pressure, and other conditions are established by means of finite element analysis to determine the maximum thickness of the flexible material, the maximum area and thickness of the hard silicon material, the position and shape of the pad, and other structural parameters in the island-bridge structure under bending conditions, so as to ensure the structural stability under bending conditions.

[0045] It can be understood that a single flexible Hall angle sensor can be provided with one grain 101 or multiple grains 101, and the embodiments of the present application do not make specific limitations thereon; in the case of multiple grains 101, the single flexible Hall angle sensor of the embodiments of the present application can measure multiple Hall voltage signals, and based on the multiple Hall voltage signals, the detection accuracy can be improved or the detection dimension can be further expanded. For example, the flexible Hall angle sensor using a single grain 101 can determine the distance of the magnetic detection object based on one Hall voltage signal, and can also be used to measure the swing angle of the detection object while the detection object only swings relatively, and the flexible Hall angle sensor using a linear arrangement to arrange multiple grains 101 can more accurately determine the distance or swing angle of the detection object based on multiple Hall voltage signals; further, the flexible Hall angle sensor using a grid-shaped arrangement of multiple grains 101 can obtain higher detection accuracy and further have the detection capability of the two-dimensional or three-dimensional spatial position of the detection object.

[0046] In order to further understand the arrangement of the multiple grains 101, the present application provides the following specific examples:

[0047] Example one:

[0048] Referring to Figure 3 , Figure 3 is a schematic diagram of testing the flexible Hall angle sensor in a specific example of the present application, which is composed of a test magnet 300, a test object 301 (a single grain 101 flexible Hall angle sensor), a bidirectional displacement table 302, a test power supply 303, and an oscilloscope 304. The flexible Hall angle sensor is normally powered, the bidirectional displacement table 302 is moved to make the flexible Hall angle sensor in a flexed state, the test magnet 300 moves horizontally, and the experimental results measured by the oscilloscope 304 are shown in Figure 4 , which indicates that the flexible device has normal Hall sensing function.

[0049] Example two:

[0050] Referring to Figure 5 , Figure 5is a schematic diagram of a flexible Hall angle sensor adopting multiple crystal grains 101 in an embodiment of the present application. In the embodiment, multiple crystal grains 101 arranged in a linear form are provided on the same flexible Hall angle sensor, the flexible Hall angle sensor is curled into an arc shape, and the arc-shaped flexible Hall angle sensor is matched with a magnetic detection object that can swing, so as to measure the swing angle of the detection object.

[0051] It can be understood that the above examples are only used to explain the present application and cannot be understood as a limitation of the present application.

[0052] In an embodiment, referring to Figure 6 , the Hall disc 200 includes a functional layer 400 and a substrate layer 401, the functional layer 400 is provided with a via hole 402, and a circuit unit is electrically connected to the Hall disc 200 through the via hole 402 to provide a bias current for the Hall disc 200 or obtain a Hall voltage signal from the Hall disc 200, and the functional layer 400 is used to generate a Hall voltage signal at the position of the via hole 402 based on the Hall effect.

[0053] Specifically, the material of the functional layer 400 includes but is not limited to one of an N-type silicon epitaxial layer, polycrystalline silicon, a P-type epitaxial layer, an insulating layer, a metal layer, an oxide layer, a compound, germanium, InSb, and InAs. Preferably, the functional layer 400 is an N-type silicon epitaxial layer.

[0054] Specifically, the material of the substrate layer 401 includes but is not limited to one of an N-type epitaxial layer, polycrystalline silicon, a P-type epitaxial layer, an insulating layer, a metal layer, an oxide layer, and a P-type substrate layer 401. Preferably, the substrate layer 401 is a P-type substrate layer 401.

[0055] In addition, in an embodiment, the functional layer 400 adopts one or more of an N epitaxial layer, an N deep buried layer, and a low-voltage N well; the substrate layer 401 adopts one of a high-voltage P well, a low-voltage P well, a P-type substrate, and a P deep buried layer, and the via hole 402 adopts an N-type material as a passage to directly connect the conductive circuit 102.

[0056] In an embodiment, the connection between the conductive circuit 102 and the die 101 adopts one or more of the bonding metal wire 103, the solder, the conductive glue with free form control, the conductive silver paste, and the anisotropic conductive glue; wherein, in the case of adopting the bonding metal wire 103 for the connection between the conductive circuit 102 and the die 101, the die 101 is directly or indirectly attached to the flexible substrate 100 through the side of the substrate layer 401; in the case of adopting one or more of the solder, the conductive glue with free form control, the conductive silver paste, and the anisotropic conductive glue for the connection between the conductive circuit 102 and the die 101, the die 101 is directly or indirectly attached to the flexible substrate 100 through the side of the via; for example, in the case of adopting the anisotropic conductive glue conductive in the vertical direction to fix the die 101 on the flexible substrate 100, the direction of the die 101 is inverted compared to the direction when adopting the bonding metal wire 103, that is, the electrical connection between the die 101 and the conductive circuit 102 is also directly completed by the anisotropic conductive glue, and at the same time, the fixing and the electrical connection are completed, and the certain deformation ability of the anisotropic conductive glue also makes it more suitable for the bending of the whole sensor, and the vertical direction conductive characteristic avoids the occurrence of short circuit. Therefore, it can be understood that, Figure 1 The way of adopting the bonding metal wire 103 to connect the die 101 and the conductive circuit 102 in the above embodiment is exemplary and does not constitute a limitation on the technical solutions of the present application.

[0057] Specifically, if the bonding metal wire 103 is adopted to connect the conductive circuit 102 and the die 101, the side of the substrate layer 401 of the die 101 is attached to the flexible substrate 100, one end of the bonding metal wire 103 is connected to the die 101 from above the die 101, and the other end is bent downward to connect the conductive circuit 102. While the other ways are adopted to connect the conductive circuit 102 and the die 101, the direction of the die 101 is inverted compared to the former.

[0058] Specifically, the material of the flexible substrate 100 includes one or more of PI, PDMS, TPU, SU8, photoresist, PET, PMMA, PVA, PEN, paper sheet and textile material; the material of the conductive circuit 102 is adapted to the stretchability of the material of the flexible substrate 100, and includes one or more of gold, silver, copper, iron, alloy, stretchable conductive silver paste, PEDOT:PSS or gallium-indium alloy; in addition, to adapt to the stretchability of the material of the flexible substrate 100, the conductive circuit 102 correspondingly adopts an island-bridge structure to protect the conductive path under large stretching conditions. For example, a part of the conductive circuit 102 is arranged as a rigid island, such as the position of the conductive circuit 102 required to be electrically connected with the die 101 is arranged as a rigid island to ensure the stability of the connection; at the same time, the part required to bear more stretching or bending is arranged as a flexible bridge, and the part belonging to the flexible bridge adopts a serpentine arranged metal circuit or adopts a stretchable conductive silver paste, PEDOT:PSS or gallium-indium alloy and the like as the conductive circuit 102 of the flexible bridge part which has the stretchable conductive ability.

[0059] With reference to Figure 7 , Figure 7 is a cross-sectional view of the die 101 mounted on the flexible substrate 100 in an embodiment of the present application, in which the conductive circuit 102 is connected with the die 101 by the bonding metal wire 103, and the flexible Hall angle sensor further includes a covering layer 104, the bonding metal wire 103 connects the conductive circuit 102 and the circuit unit, and the covering layer 104 covers the flexible substrate 100, the die 101 and the bonding metal wire 103 at the same time, and the covering layer 104 is used to protect the bonding metal wire 103 and disperse the stress received by the die 101 in the case that the flexible Hall angle sensor is deformed.

[0060] It can be understood that under small radius bending, the stress received by the die 101 is absorbed by the flexible substrate 100 and the covering layer 104, and does not affect the normal work of the die 101, the die 101 can convert the magnetic induction intensity into the Hall voltage, and the built-in amplifier amplifies the signal, so that the output signal is proportional to the magnetic induction intensity, which can be used as a magnetic field sensor and has the function of flexibility and bendability. Since a single magnetic field sensor can accurately identify the transverse position of a magnet within a certain range, a plurality of magnetic field sensors can be installed in an arc shape to accurately identify the circumferential position of a magnet within a certain range.

[0061] Specifically, the material of the bonding metal wire 103 includes but is not limited to one of gold, silver, copper, iron, alloy. Preferably, the bonding metal wire 103 is gold.

[0062] Specifically, the PDMS or other flexible material is used as the cover layer 104, a three-dimensional model of the flexible substrate 100 and the crystal grain 101 carried thereby is established according to finite element analysis, experimental conditions of different bending radii are set, and structural parameters such as the thickness of the cover layer 104, the thickness of the flexible substrate 100, the Young's modulus, the maximum allowable area and thickness of the crystal grain 101, the maximum bendable radius, and the maximum stretchable upper limit of the bonding wire are determined to ensure that the local stress under bending does not exceed the breaking limit of the bonding wire and to ensure mechanical stability.

[0063] Specifically, the cover layer 104 material includes but is not limited to PI, PDMS, SU8, photoresist, PET, PMMA, PVA, PEN, paper sheet, and textile material. Preferably, the cover layer 104 uses PDMS.

[0064] Specifically, the parameters of the flexible substrate 100 and the cover layer 104 are optimized to improve the mechanical performance of the overall sensor. For example, the flexible substrate 100 uses PI, that is, the sensor is constructed in the form of a common FPC, and the cover layer 104 uses PDMS. In order to ensure that the local stress under bending of the sensor does not exceed the breaking limit of the bonding metal wire 103 and to ensure mechanical stability, a three-dimensional model of the FPC and the crystal grain 101 carried thereby can be established according to finite element analysis, experimental conditions of different bending radii are set, and structural parameters such as the thickness of the PDMS layer, the thickness of the PI substrate, the Young's modulus, the maximum allowable area and thickness of the silicon crystal grain 101, the maximum bendable radius, and the maximum stretchable upper limit of the metal bonding wire are determined.

[0065] In an embodiment, the flexible Hall angle sensor further comprises an electromagnetic shielding structure, which comprises one or more of the following in combination: the cover layer 104 and the flexible substrate 100 diffused with conductive particle material, and a stretchable conductive fabric or conductive sponge wrapped around the periphery of the flexible Hall angle sensor; wherein the cover layer 104 and the flexible substrate 100 are insulated by pre-polymerization to avoid short circuit. By setting the electromagnetic shielding structure, the working stability of the flexible Hall angle sensor can be further enhanced.

[0066] In an embodiment, the flexible Hall angle sensor is further provided with a reinforcement structure for increasing the Young's modulus of part of the area to improve durability. The reinforcement structure uses one or more of the following: an island bridge structure formed after local hardening treatment of the flexible substrate 100, a layered structure, a porous structure or a foam structure provided on the cover layer 104 through topology optimization, and combinations thereof.

[0067] Specifically, in order to increase the Young's modulus of the flexible substrate 100 layer, an island-bridge design can be adopted, and the local flexible substrate 100 is hardened by using copper, gold and the like, and the peripheral cover layer 104 can also use a more complex layered structure, topology optimization, porous structure or foam structure, microstructure regulation and the like to improve the Young's modulus.

[0068] It can be understood that the island-bridge structure contained in the above reinforcing structure or formed integrally with the sensor can correspond to the connection or pad of the crystal grain 101 or the bonding metal wire 103 and the conductive circuit 102, so as to enhance the mechanical performance of the flexible Hall angle sensor, and increase the bendable curvature or the upper limit of the stretchability while maintaining stability.

[0069] Referring to Figure 2 In an embodiment, the circuit unit includes an amplifier circuit 201, a reference power supply 202 electrically connected to the amplifier circuit 201, and an output buffer circuit 203 electrically connected to the amplifier circuit 201, and the output buffer circuit 203 is electrically connected to the conductive circuit 102.

[0070] The amplifier circuit 201 is electrically connected to the Hall disc 200 to obtain and amplify the Hall voltage signal output by the Hall disc 200, and the output buffer circuit 203 is used to obtain and optimize the Hall voltage signal from the amplifier circuit 201 and then output to the conductive circuit 102.

[0071] Specifically, the amplifier circuit 201 adopts a chopper amplifier to convert a direct current signal into a high-frequency signal to avoid low-frequency noise, and periodically eliminates amplifier offset, thereby improving the accuracy of the sensor.

[0072] Specifically, the circuit unit further includes a bias current source 204 arranged between the conductive circuit 102 and the Hall disc 200, and the bias current source 204 is provided with a PTAT (Proportional to Absolute Temperature Current) current circuit, and the bias current source 204 adjusts the size of the bias current according to the temperature based on the PTAT current circuit to provide temperature compensation for the Hall disc 200 and the amplifier circuit 201 while supplying power, so as to ensure that the flexible Hall angle sensor of the embodiment always maintains high accuracy at different temperatures.

[0073] Specifically, the bias current source 204 compensates for the temperature characteristics of the Hall disc 200 and the amplifier circuit 201 by using a multi-section temperature compensation method, and a PTAT current circuit is arranged before the current source, and temperature division points such as 0°C and 60°C are set, and the size of the bias current is adjusted for the low-temperature zone, the room-temperature zone and the high-temperature zone, and the adjustment parameters are determined according to the experimental test results, so that the sensitivity drift of the sensor can be reduced at different temperatures, and temperature compensation is achieved.

[0074] It can be understood that the structure of the amplifier circuit 201, the output buffer circuit 203, the reference power supply 202 and the bias current source 204 in the circuit unit is not limited in the embodiment of the present application, and the corresponding function can be realized.

[0075] In addition, with reference to Figure 8 The embodiment of the present application also provides an angle detection system, which comprises the flexible Hall angle sensor 500 in the above embodiment of the present application; the angle detection system further comprises an outer ring 501, a magnet 502, an inner rotating shaft 503 and a data acquisition module 504; wherein the flexible Hall angle sensor 500 is bent and attached to the outer ring 501, the inner rotating shaft 503 is arranged in the outer ring 501, the magnet 502 is mounted on the inner rotating shaft 503 corresponding to the flexible Hall angle sensor 500, and the data acquisition module 504 is electrically connected with the flexible Hall angle sensor 500.

[0076] Further, when the inner rotating shaft 503 causes the magnet 502 to displace to cause the relative position of the magnet 502 and the crystal grain 101 on the flexible Hall angle sensor 500 to change and the Hall voltage signal of the crystal grain 101 to change correspondingly under the condition that the inner rotating shaft 503 causes the angle to change, the data acquisition module 504 is used for acquiring and analyzing the Hall voltage signal of the crystal grain 101 to obtain the angle information of the inner rotating shaft 503.

[0077] Specifically, the flexible Hall angle sensor 500 provided with the six crystal grains 101 arranged in a one-dimensional form in the above example one is arranged in the angle detection system in Figure 8 The measurement result is as shown in Figure 9 Therefore, based on the Hall voltage signals of the plurality of crystal grains 101, the detection range of the angle can be expanded, and the detection accuracy can be improved. In addition, by reading the voltage output by the Hall element in real time, in the back-end algorithm arranged on the side of the data acquisition module 504, the Hall voltage signal data is taken as an input layer, the angle is taken as an output layer, one or more of the following modes is used for machine autonomous learning, that is, a segmented linear interpolation, a standard Kalman filter, an extended Kalman filter, a sparse Kalman filter, a feedforward neural network, a convolutional neural network, a recurrent neural network and variants, an autoencoder and a graph neural network, and the angle measurement accuracy reaches 0.1°.

[0078] The device embodiments described above are only schematic, wherein the units described as separate components can or can not be physically separate, that is, can be located in one place, or can be distributed on a plurality of network units. According to actual needs, part or all of the modules can be selected to realize the purpose of the embodiment scheme.

[0079] As will be appreciated by one of ordinary skill in the art, all or some of the steps, systems, and techniques disclosed herein can be embodied in software, firmware, hardware, and / or suitable combination thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application- specific integrated circuit. Such software can be distributed on computer readable media, which can comprise computer storage media (or non-transitory media) and communication media (or transitory media). As will be appreciated by one of ordinary skill in the art, the term computer storage media includes all tangible and non-tangible, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Further, as will be appreciated by one skilled in the art, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media.

[0080] While the embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary and are not to be taken as limiting the scope of the application. The scope of the application is defined by the claims and their equivalents.

Claims

1. An angle detection system, characterized by, The flexible Hall angle sensor comprises: a flexible substrate and a die fixed to the flexible substrate, the flexible substrate being provided with a conductive circuit electrically connected to the die; the die is provided with a Hall disc for converting a magnetic field signal into a Hall voltage signal and a circuit unit for supporting the operation of the Hall disc, the Hall disc being electrically connected to the conductive circuit through the circuit unit, the conductive circuit being used for powering the Hall disc and transmitting the Hall voltage signal and the conductive circuit being capable of deforming with the bending or stretching of the flexible substrate while maintaining the conductive performance; the die is provided with a plurality of dies arranged in an array on the flexible substrate and forming an island-bridge arrangement with the flexible substrate; wherein the array of the die is obtained based on a finite element analysis of the island-bridge arrangement to ensure that the flexible Hall angle sensor has a reasonable strain distribution under bending conditions and improves the allowable bending curvature thereof; the angle detection system further comprises an outer ring, a magnet, an inner rotating shaft and a data acquisition module; the flexible Hall angle sensor is bent and attached to the outer ring, the inner rotating shaft is arranged in the outer ring, and the inner rotating shaft is provided with the magnet corresponding to the flexible Hall angle sensor, and the data acquisition module is electrically connected to the flexible Hall angle sensor; when the inner rotating shaft causes the magnet to displace to cause a change in the relative position of the die on the flexible Hall angle sensor and the magnet to cause a corresponding change in the Hall voltage signal of the die, the data acquisition module is used to acquire and analyze the Hall voltage signal of the die to obtain the angle information of the inner rotating shaft.

2. The angle detection system of claim 1, wherein The Hall disc comprises a functional layer and a substrate layer, the functional layer is provided with a via, the circuit unit is electrically connected to the Hall disc through the via to provide a bias current for the Hall disc or obtain a Hall voltage signal from the Hall disc, and the functional layer is used to generate a Hall voltage signal at the position of the via based on the Hall effect.

3. The angle detection system of claim 2, wherein The functional layer adopts one or more of an N epitaxial layer, an N deep buried layer and a low-voltage N well; the substrate layer adopts one of a high-voltage P well, a low-voltage P well, a P-type substrate and a P deep buried layer, and the via adopts an N-type material as a path to directly connect the conductive circuit.

4. The angle detection system of claim 3, wherein The connection between the conductive circuit and the die adopts one or more of a bonding metal wire, a welding point, a shape-free conductive adhesive, a conductive silver paste and an anisotropic conductive adhesive; wherein, in the case that the connection between the conductive circuit and the die adopts a bonding metal wire, the die is directly or indirectly attached to the flexible substrate through one side of the substrate layer; in the case that the connection between the conductive circuit and the die adopts one or more of a welding point, a shape-free conductive adhesive, a conductive silver paste and an anisotropic conductive adhesive, the die is directly or indirectly attached to the flexible substrate through one side of the via. The material of the flexible substrate comprises one or more of PI, PDMS, TPU, SU8, photoresist, PET, PMMA, PVA, PEN, paper sheet and textile material; the material of the conductive circuit is adapted to the tensile property of the material of the flexible substrate, comprising one or more of gold, silver, copper, iron, alloy, stretchable conductive silver paste, PEDOT:PSS or gallium-indium alloy; in addition, to adapt to the tensile property of the material of the flexible substrate, the conductive circuit correspondingly adopts an island-bridge structure to protect the conductive path under large stretching conditions.

5. The angle detection system of claim 4, wherein The conductive circuit is connected with the die via a bonding metal wire, the flexible Hall angle sensor further comprises a cover layer, the bonding metal wire connects the conductive circuit and the circuit unit, and the cover layer covers the flexible substrate, the die and the bonding metal wire at the same time, and the cover layer is used to protect the bonding metal wire and disperse the stress received by the die in the case that the flexible Hall angle sensor is deformed.

6. The angle detection system of claim 5, wherein Further comprising an electromagnetic shielding structure, the electromagnetic shielding structure comprises a combination of one or more of the following: the cover layer and the flexible substrate diffused with conductive particle materials, and stretchable conductive fabric or conductive sponge wrapped on the periphery of the flexible Hall angle sensor; wherein the cover layer and the flexible substrate are insulated by pre-polymerization to avoid short circuit; In addition, the flexible Hall angle sensor is further provided with a reinforcement structure for increasing the Young's modulus of part of the area to improve the durability, the reinforcement structure adopts one or more of the following: an island-bridge structure formed after the flexible substrate is subjected to local hardening treatment, a layered structure, a porous structure or a foam structure provided on the cover layer through topology optimization and a combination thereof.

7. The angle detection system of claim 1, wherein The circuit unit comprises an amplifier circuit, a reference power supply and an output buffer circuit electrically connected with the amplifier circuit, and the output buffer circuit is electrically connected with the conductive circuit; The amplifier circuit is electrically connected with the Hall disc to obtain and amplify the Hall voltage signal output by the Hall disc, and the output buffer circuit is used to obtain and optimize the Hall voltage signal from the amplifier circuit and then output to the conductive circuit.

8. The angle detection system of claim 7, wherein, The circuit unit further comprises a bias current source arranged between the conductive circuit and the Hall disc, the bias current source is provided with a PTAT current circuit, and the bias current source adjusts the size of the bias current based on the PTAT current circuit according to the temperature to provide temperature compensation for the Hall disc and the amplifier circuit while realizing power supply.

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