Differential Hall current sensor and manufacturing method thereof

Abstract

The embodiment of the present invention provides a differential Hall current sensor and a manufacturing method thereof, belonging to the field of semiconductor technology. The differential Hall current sensor includes: a substrate; a magnetic yoke, having a semi-enclosed structure consisting of a bottom surface and two side surfaces located on the same side of the bottom surface, and the bottom surface is bonded to the substrate; a current row, placed in the cavity of the semi-enclosed structure and allowing the two ends of the current row to extend from the semi-enclosed structure; an insulating layer, arranged on the upper surface of the current row and located in the cavity; at least two Halls, symmetrically arranged on both sides of the upper surface of the insulating layer along the current direction; at least two groups of magnetic concentrators, arranged against the magnetic sensing surfaces of at least two Halls; at least two groups of magnetic concentrators and the magnetic yoke form a conductive magnetic circuit, which deflects the magnetic field component of the current magnetic field in the direction parallel to the magnetic sensing surface into the magnetic field component in the perpendicular direction thereof. The differential Hall current sensor of the present invention enhances the Hall-perceivable magnetic field strength and improves the measurement sensitivity by concentrating the conductive magnetic circuit of the current magnetic field.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and in particular relates to a differential Hall current sensor and a manufacturing method thereof. Background Art

[0002] At present, Hall sensors with integrated Hall elements or Hall chips are widely used for efficient measurement of electrical signals. With the technological updates in the fields of new energy, energy storage, battery management, etc., higher requirements are put forward for the measurement sensitivity and measurement range of Hall sensors.

[0003] Since the Hall sensor can only detect magnetic fields perpendicular to its magnetic sensing surface, in order to utilize the perpendicular magnetic field generated by the current, the existing Hall sensor uses two Hall sensors placed on both sides of the current row and narrows the width of the current row at this point. This solution causes the current row to heat up due to the concentration of current in the narrowed part, and its measurement range is also greatly limited.

[0004] Another solution is to install the Hall sensor on the current bus and add a magnetic core or a larger magnetic yoke structure to amplify the magnetic field. Although this can expand the range of current detection, it is difficult to install and maintain on the one hand, and the use of silicon-based Hall reduces its sensitivity on the other.

[0005] In addition, there are also current sensors that use the shunt resistor method, which calculates the current by connecting a resistor with a very small resistance in series with the current bank and measuring the voltage across it. However, the resistance of this solution will cause measurement errors due to temperature changes. Compared with the Hall current sensor, its accuracy and stability are obviously insufficient.

[0006] In view of this, it is necessary to optimize the design of a new Hall current sensor and a manufacturing method thereof to completely or partially solve the defects of the above current sensor. Summary of the invention

[0007] In order to solve at least one aspect of the above problems and defects in the prior art, the embodiments of the present invention provide a differential Hall current sensor and a manufacturing method thereof, which forms a conductive magnetic circuit by gathering the current magnetic field to enhance the magnetic field strength that the Hall can perceive and improve the measurement sensitivity. The technical solution is as follows:

[0008] According to one aspect of the present invention, a differential Hall current sensor is provided, the differential Hall current sensor comprising:

[0009] substrate;

[0010] A yoke having a semi-enclosed structure consisting of a bottom surface and two side surfaces located on the same side of the bottom surface, wherein the bottom surface of the semi-enclosed structure is bonded to the substrate;

[0011] A current bar is placed in the cavity of the semi-enclosed structure and allows both ends of the current bar to extend out of the semi-enclosed structure;

[0012] an insulating layer disposed on an upper surface of the current bank and located in the cavity;

[0013] At least two Halls are symmetrically arranged on both sides of the upper surface of the insulating layer along the current direction;

[0014] At least two groups of magnetic concentrators, each group of magnetic concentrators being arranged close to the magnetic sensing surfaces of at least two Hall electrodes;

[0015] At least two groups of magnetic focusing blocks and the magnetic yoke form a conducting magnetic circuit, which deflects the magnetic field component of the current magnetic field in a direction parallel to the magnetic sensing surface of the Hall into a magnetic field component in a direction perpendicular to the magnetic sensing surface.

[0016] In some embodiments, specifically, the magnetic yoke is formed as an integral piece, and its semi-enclosed structure is composed of a bottom magnetic focusing plate and a first side magnetic focusing plate and a second side magnetic focusing plate located at both ends of the same side of the bottom magnetic focusing plate, and its cavity is formed by surrounding the bottom magnetic focusing plate, the first side magnetic focusing plate and the second side magnetic focusing plate.

[0017] In some embodiments, further, the current bus extends from both sides of the cavity where no side magnetic focusing plates are provided and is connected in series with the external current bus to be measured, and the magnetic field generated by the current bus to be measured is gathered by the magnetic yoke.

[0018] In some embodiments, an IC circuit part is also disposed on the substrate, and at least two Halls output measurement signals after being differentiated by the IC circuit part.

[0019] In some embodiments, the at least two Halls include at least one pair of Halls located in a semi-enclosed structure of the magnetic yoke and centrally symmetrically arranged on both sides of the upper surface of the insulating layer, and one pair of Halls in the at least one pair of Halls includes a first Hall and a second Hall arranged oppositely.

[0020] In some embodiments, the at least two groups of magnetic focusing blocks are two groups of magnetic focusing blocks, and the two groups of magnetic focusing blocks include a first group of magnetic focusing blocks and a second group of magnetic focusing blocks.

[0021] Specifically, the first group of magnetic focusing blocks includes a first magnetic focusing block centrally symmetrically arranged above each pair of Halls in at least one pair of Halls, the first magnetic focusing block is respectively attached to the upper magnetic sensing surface of each pair of Halls, and the first magnetic focusing block is located in the middle area of ​​the two Halls of each pair of Halls.

[0022] Specifically, the second group of magnetic focusing blocks includes a second magnetic focusing block and a third magnetic focusing block which are centrally symmetrically arranged between each pair of Halls in at least one pair of Halls and the insulating layer, the second magnetic focusing block and the third magnetic focusing block are located in the cavity of the magnetic yoke, the second magnetic focusing block and the third magnetic focusing block are respectively abutted against the lower magnetic induction surface of each pair of Halls, the end of the second magnetic focusing block away from the center of the current row abuts against the inner side of the magnetic focusing plate on the first side of the magnetic yoke, and the end of the third magnetic focusing block away from the center of the current row abuts against the inner side of the magnetic focusing plate on the second side of the magnetic yoke.

[0023] Further, the first magnetic focusing block, the second magnetic focusing block and the third magnetic focusing block are arranged symmetrically about the center of the current row and their plane projections coincide with the Hall center area of ​​the differential Hall current sensor.

[0024] Further, in each pair of at least one pair of Halls, there is a first gap between the first Hall and the second Hall, and the first gap is set to a predetermined distance or equal to zero; there is a second gap between the second magnetic focusing block and the third magnetic focusing block.

[0025] In some embodiments, the at least two groups of magnetic focusing blocks are two groups of magnetic focusing blocks, and the two groups of magnetic focusing blocks include a first group of magnetic focusing blocks and a second group of magnetic focusing blocks.

[0026] Specifically, the first group of magnetic focusing blocks includes a first magnetic focusing block centrally symmetrically arranged between each pair of Halls in at least one pair of Halls and the insulating layer, the first magnetic focusing block is respectively attached to the lower magnetic sensing surface of each pair of Halls, and the first magnetic focusing block is located in the middle area of ​​the two Halls of each pair of Halls.

[0027] Specifically, the second group of magnetic blocks includes a second magnetic block and a third magnetic block which are centrally symmetrically arranged above each pair of Halls in at least one pair of Halls; the second magnetic block and the third magnetic block are located in the cavity of the magnetic yoke, and the second magnetic block and the third magnetic block are respectively attached to the upper magnetic induction surface of each pair of Halls, and the end of the second magnetic block away from the center of the current row is attached to the inner side of the magnetic plate on the first side of the magnetic yoke, and the end of the third magnetic block away from the center of the current row is attached to the inner side of the magnetic plate on the second side of the magnetic yoke.

[0028] Further, the first magnetic focusing block, the second magnetic focusing block and the third magnetic focusing block are arranged symmetrically about the center of the current row and their plane projections coincide with the Hall center area of ​​the differential Hall current sensor.

[0029] Further, in each pair of at least one pair of Halls, there is a first gap between the first Hall and the second Hall, and the first gap is set to a predetermined distance or equal to zero; there is a second gap between the second magnetic focusing block and the third magnetic focusing block.

[0030] In some embodiments, when any one of the at least one pair of Hall sensors is an integrated Hall element, the pins of the integrated Hall element are directly soldered to the Hall element circuit disposed on the substrate and then connected to the signal processing circuit disposed on the substrate.

[0031] In some embodiments, when any one of at least one pair of Hall sensors is a Hall bare chip, the Hall bare chip is directly placed in the cavity of the magnetic yoke, and is connected to the Hall chip circuit through metal wires, and then connected to the signal processing circuit provided on the substrate.

[0032] In some embodiments, the at least one pair of Hall cells includes at least two pairs of Hall cells arranged in parallel on the insulating layer, wherein two adjacent pairs of Hall cells in the at least two pairs of Hall cells are arranged at intervals.

[0033] In some embodiments, the cross-sectional shape of any one of the at least two groups of magnetic focusing blocks is a centrally symmetrical shape, and the centrally symmetrical shape is any one of a rhombus, a square, a rectangle, a circle, and an ellipse.

[0034] In some embodiments, the material of at least two groups of magnetic blocks and magnetic yokes is a high magnetic permeability material that is non-magnetic itself, and the high magnetic permeability material is any one of ferrite, soft magnet, and nano-magnetic crystal.

[0035] In some embodiments, the material of each Hall in the at least two Hall electrodes is a Hall material, and the Hall material is any one of GaAs, InSb, and InAs.

[0036] According to another aspect of the present invention, a method for manufacturing a differential Hall current sensor is provided, for manufacturing the differential Hall current sensor described according to the above aspect, the manufacturing method comprising:

[0037] manufacturing substrates;

[0038] manufacturing a yoke having a semi-enclosed structure consisting of a bottom surface and two side surfaces located on the same side of the bottom surface, wherein the bottom surface of the semi-enclosed structure is bonded to a substrate;

[0039] Manufacturing a device frame, arranging a current bar in the device frame, and bonding the current bar in the device frame to the cavity of the semi-enclosed structure and allowing both ends of the current bar to extend out of the semi-enclosed structure;

[0040] manufacturing an insulating layer disposed on an upper surface of the current bus and located in the cavity;

[0041] At least two Hall electrodes are symmetrically arranged on both sides of the upper surface of the insulating layer along the current direction;

[0042] At least two groups of magnetic focusing blocks are manufactured, and each group of magnetic focusing blocks of the at least two groups of magnetic focusing blocks is arranged close to the magnetic sensing surfaces of at least two Halls;

[0043] At least two groups of magnetic concentrators and a magnetic yoke form a conducting magnetic circuit, through which the magnetic field components of the current magnetic field in the direction parallel to the magnetic sensing surfaces of at least two Hall electrodes are deflected into magnetic field components in the direction perpendicular to the magnetic sensing surfaces;

[0044] The coefficient of the current flowing through each pair of Halls constituting a pair of at least two Halls and the Hall voltage is obtained by calibration measurement.

[0045] The differential Hall current sensor and the manufacturing method thereof provided by the embodiments of the present invention have at least one or part of the following advantages:

[0046] (1) The differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention gather the magnetic field generated by the current row to be measured through the magnetic yoke and the magnetic concentrator to form a conductive magnetic circuit, thereby increasing the magnetic flux density, enhancing the magnetic field strength that can be perceived by the Hall, and improving the measurement sensitivity;

[0047] (2) The differential Hall current sensor and its manufacturing method provided in the embodiments of the present invention use two groups of staggered magnetic concentrators to deflect the magnetic field component that cannot be sensed by the Hall current to the direction of the magnetic field that can be sensed by the Hall current in whole or in part, thereby further enhancing the perceptible magnetic field strength.

[0048] (3) The differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention ensure the alignment accuracy of the relative position of the internal Hall and the current row to be measured by connecting the preset current row in series with the current row to be measured, and have good consistency, thereby reducing the measurement error;

[0049] (4) The differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention set the Hall on a preset current row, so as to avoid the spacing between the Halls on both sides being affected by the increase in the width of the actual current row to be measured. The spacing between the Halls on both sides can be reduced to zero, thereby reducing the size of the packaging structure and helping to improve the Hall anti-interference performance.

[0050] (5) The gaps between the magnetic collecting blocks and the gaps between the paired Halls of the differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention can be designed accordingly according to the actual width of the current row to be measured and the measurement requirements without affecting the overall magnetic collecting effect, and are generally applicable to the measurement of currents in various ranges;

[0051] (6) The differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention can flexibly arrange multiple pairs of Halls and the magnetic concentrators attached to their magnetic sensing surfaces, and can also flexibly design the shape of the magnetic concentrators. The mature processing method is used, the process is simple, and no additional manufacturing cost is added.

[0052] (7) The differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention arrange the Hall electrodes symmetrically in pairs on the current row, eliminate interference signals in the measurement process through the differential circuit, improve the measurement sensitivity and accuracy, and are particularly conducive to sensing extremely small current values, thereby expanding the range of the differential Hall current sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of the preferred embodiments in conjunction with the accompanying drawings, in which:

[0054] Figure 1A is a schematic top view of a packaging structure of a differential Hall current sensor according to Embodiment 1 of the present invention;

[0055] Figure 1B for Figure 1A A cross-sectional schematic diagram of the packaging structure of the differential Hall current sensor shown;

[0056] Figure 2 for Figure 1A and Figure 1B A schematic diagram of magnetic lines of force of a conducting magnetic circuit and magnetic field components on the Hall surface formed by the differential Hall current sensor of Example 1 under a current magnetic field B is shown;

[0057] Figure 3 is a schematic cross-sectional view of a packaging structure of a differential Hall current sensor according to Embodiment 2 of the present invention;

[0058] Figure 4 is a schematic top view of a packaging structure of a differential Hall current sensor according to Embodiment 3 of the present invention;

[0059] Figure 5 is a schematic top view of a packaging structure of a differential Hall current sensor according to Embodiment 4 of the present invention;

[0060] Figure 6 Schematic top view of the packaging structure of the differential Hall current sensor according to Embodiment 5 of the present invention. DETAILED DESCRIPTION

[0061] The technical solution of the present invention is further specifically described below by examples and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation of the present invention.

[0062] It should also be understood that, although the terms "first", "second", "third", etc. may be used in the following embodiments of the present invention to describe that a component includes two or more components, these components should not be limited to these terms, which are only used to distinguish each component from each other. And the descriptions of "upper", "lower", etc. indicating directions are only for illustrative purposes to illustrate the relative positions of components or the relative directions of, for example, current, magnetic field, magnetic field components, etc., and should not be understood as a limitation of the present invention.

[0063] Nowadays, with the development of technology in the fields of advanced electronic systems, new energy, energy storage, etc., Hall current sensors based on the Hall effect are widely used in current detection of various electronic devices and measurement of non-electrical physical quantities such as torque, displacement, acceleration, speed, etc. Therefore, higher requirements are put forward for the performance parameters such as measurement sensitivity and range of Hall sensors.

[0064] Based on the above requirements, in order to further enhance the perceptible magnetic field strength of the Hall sensor and reduce the influence of signal interference on the Hall, according to one aspect of the present invention, an embodiment of the present invention provides a novel differential Hall current sensor 100. Figure 1A and Figure 1B , shows the structure of the differential Hall current sensor 100, which mainly includes the following six parts:

[0065] substrate 10;

[0066] The yoke 20 has a semi-enclosed structure consisting of a bottom surface and two side surfaces located on the same side of the bottom surface, and the bottom surface of the semi-enclosed structure is bonded to the substrate 10;

[0067] The current bar 30 is placed in the cavity of the semi-enclosed structure of the yoke 20 and allows both ends of the current bar 30 to extend from the semi-enclosed structure;

[0068] an insulating layer 40 disposed on the upper surface of the current bar 30 and located in the cavity of the semi-enclosed structure of the yoke 20;

[0069] At least two Halls 50 are symmetrically arranged on both sides of the upper surface of the insulating layer 40 along the current direction;

[0070] At least two groups of magnetic concentrators 60 are disposed close to the magnetic sensing surfaces of at least two Halls 50;

[0071] At least two groups of magnetic focusing blocks 60 and the magnetic yoke 20 form a conducting magnetic circuit to deflect the magnetic field component of the current magnetic field in the direction parallel to the magnetic sensing surface of the Hall (for example, at least two Halls 50) into a magnetic field component in the direction perpendicular to its magnetic sensing surface.

[0072] In one example, if Figure 1A The top view of the differential Hall current sensor 100 is shown, wherein a substrate 10 is shown, and the substrate 10 is divided into two parts: a sensing part 11 and a circuit part 12. A magnetic yoke 20, a current row 30, an insulating layer 40, at least two Halls 50 and at least two groups of magnetic focusing blocks 60 are sequentially arranged on the sensing part 11.

[0073] In one example, preferably, an IC circuit part is set on the circuit part 12, and the IC circuit part supplies power to at least two Halls 50. The magnetic field generated by the current to be measured is gathered by the yoke 20 and at least two groups of magnetic blocks 60, and the Hall signals generated on at least two Halls 50 are output to the IC circuit part through leads, and then the measurement signal is output through pin 121 after differential processing by the IC circuit part.

[0074] In one example, the current bus 30 extends from both sides of the cavity of the yoke 20 ( Figure 1A The magnetic field generated by the current row to be measured is gathered by the magnetic yoke 20. Figure 1A Within the package range (the package line dashed box) of the package shown, the current row 30 can be widened in the package according to the width of the current row to be tested that is actually connected in series ( Figure 1A The top view shows the widened situation, that is, the width of the current bus at both ends beyond the package range becomes larger to match the current bus to be measured that is actually connected in series). It can also be chosen not to widen according to the actual situation of the current bus to be measured. Afterwards, a number of openings 31 are provided at both ends of the current bus 30 in the part extending out of the package body, and the current bus to be measured is fixedly connected in series through the openings 31 to form a straight-through current bus. At this time, the current of the current bus to be measured and the current bus 30 are directly connected up and down. Compared with the curved current bus of the traditional Hall current sensor, the current bus 30 of this embodiment can use a wider current bus to reduce the heat caused by the current concentration due to the narrowing of the current bus width, and can also save the device installation space.

[0075] In one example, considering that the function of the magnetic yoke 20 and the at least two magnetic concentrators 60 is to gather the current magnetic field by forming a conductive magnetic circuit, a high magnetic permeability material that is non-magnetic itself is selected to make the magnetic yoke 20 and the at least two magnetic concentrators 60. Theoretically, any high magnetic permeability material that is non-magnetic itself can be used to manufacture the magnetic yoke 20 and the at least two magnetic concentrators 60. Preferably, the high magnetic permeability material can be any one of ferrite, soft magnet, and nano-magnetic crystal, for example.

[0076] In one example, alternatively, the material of each Hall in the at least two Halls 50 is a Hall material. Theoretically, any material that can produce the Hall effect (i.e., Hall material) can be used to manufacture the Hall in the present invention and its embodiments. Preferably, the Hall material can use, for example, GaAs, InSb, InAs, and other III-V semiconductor materials or other types of semiconductor materials.

[0077] For the specific selection of high magnetic permeability materials and Hall materials, existing technical means can be used to select the best according to the actual design requirements of the differential Hall current sensor 100. Those skilled in the art can select suitable high magnetic permeability materials to make the yoke 20 and the magnetic concentrator 60 according to the actual measurement scenario, and select suitable Hall materials to make the Hall 50. This example only provides some illustrative examples, and those skilled in the art should not be understood as a limitation of the present invention.

[0078] Based on the basic structure of the differential Hall current sensor 100, considering that various measurement scenarios may occur in actual use, it is necessary to adjust the layout, selection, electrical connection, etc. of the internal components of the differential Hall current sensor 100 according to the requirements of the measurement scenario. The specific structure of the differential Hall current sensor 100 and the layout of various internal components are described in detail below through 5 embodiments.

[0079] Example 1

[0080] Figure 1A and Figure 1B The structure of the differential Hall current sensor 100 of the first embodiment is shown. Figure 2 shows that when current flows (in Figure 1A The magnetic lines of force and magnetic field components of the internal conductive magnetic circuit of the differential Hall current sensor 100 are shown in FIG.

[0081] Combination Figure 1A and Figure 1B As shown, the differential Hall current sensor 100 of Example 1 mainly includes six parts, namely, a substrate 10, a magnetic yoke 20, a current row 30, an insulating layer 40, two Hall elements 50 (a first Hall element 51 and a second Hall element 52, where two integrated Hall elements or two Hall bare chips can be used) and two groups of magnetic focusing blocks (wherein the first group of magnetic focusing blocks includes a first magnetic focusing block 61, and the second group of magnetic focusing blocks includes a second magnetic focusing block 62 and a third magnetic focusing block 63). The specific configuration of the six parts is described as follows.

[0082] The substrate 10, such as Figure 1B As shown, only the sensing portion 11 of the substrate 10 is shown here, and the components of the other five parts are arranged on the sensing portion 11 in sequence.

[0083] The yoke 20 is bonded to the sensing portion 11 of the substrate 10 and has a semi-enclosed structure.

[0084] Specifically, in one example, the semi-enclosed structure of the magnetic yoke 20 is composed of a bottom magnetic focusing plate 21 and a first side magnetic focusing plate 22 and a second side magnetic focusing plate 23 located at both ends of the same side of the bottom magnetic focusing plate 21, and a cavity is formed by being surrounded by the bottom magnetic focusing plate 21, the first side magnetic focusing plate 22 and the second side magnetic focusing plate 23.

[0085] In one example, preferably, the yoke 20 is made by an integrated processing and molding process, for example, by one-time molding through a photolithography process. Alternatively, the yoke 20 may also be a split type, that is, the bottom magnetic plate 21, the first side magnetic plate 22, and the second side magnetic plate 23 are separately manufactured and then assembled into the yoke 20 according to the above structure. Those skilled in the art will understand that the selection of an integrated or split manufacturing process, as well as which specific process to use are common technical means in the field, and can be selected based on actual design requirements. This example only provides some illustrative examples, and those skilled in the art should not understand it as a limitation of the present invention.

[0086] The current row 30 is placed in the cavity of the semi-enclosed structure of the magnetic yoke 20 and the two ends of the current row 30 are allowed to extend from the two sides of the cavity of the magnetic yoke 20 where the first side magnetic focusing plate 22 and the second side magnetic focusing plate 23 are not provided. The two ends of the current row 30 are connected in series with the external current row to be measured, so that the magnetic field generated by the current row to be measured is gathered through the magnetic yoke 20.

[0087] The insulating layer 40 is disposed on the upper surface of the current bus 30 and is located in the cavity of the semi-enclosed structure of the yoke 20 .

[0088] In one example, specifically, the insulating layer 40 can be made of insulating materials such as high molecular polymers, resins, fibers, ceramics, etc. For the selection of insulating materials, those skilled in the art can select suitable insulating materials according to the actual measurement scenario. This example only provides some illustrative examples, and those skilled in the art should not understand it as a limitation of the present invention.

[0089] In one example, for the differential Hall current sensor 100 using a bare Hall chip, alternatively, it is first electrically connected to the IC circuit part on the circuit part 12 through metal wires, silver glue, etc., and then the measurement signal is output through the pin 121. For the differential Hall current sensor 100 using an integrated Hall element, the IC circuit can be set in the circuit part 12, or the IC circuit can be set on the insulating layer 40, and electrically connected to the integrated Hall element (such as the pin on the Hall element) through metal wires, etc.

[0090] In the present embodiment 1, Hall bare chips are used to form a pair of Halls. Specifically, the number of at least two Halls 50 is set to 2 and forms a pair of Halls, and the pair of Halls includes a first Hall 51 and a second Hall 52. Figure 1B As shown, the pair of Hall sensors are located inside the semi-enclosed structure of the magnetic yoke 20 and are centrally symmetrically arranged on both sides of the upper surface of the insulating layer 40 along the current direction of the current row to be measured.

[0091] In one example, specifically, the first Hall 51 and the second Hall 52 use Hall bare chips. When Hall bare chips are used, they can be connected to the corresponding Hall chip circuits through metal wires, silver glue, etc., and then connected to the signal processing circuit provided on the circuit part 12 of the substrate 10.

[0092] In one example, further, there is a first gap between the first Hall 51 and the second Hall 52. Alternatively, the first gap can be set to a predetermined distance, and the specific value of the predetermined distance can be designed according to the actual measurement scenario. In addition, in extreme cases, the value of the first gap, that is, the predetermined distance, can be set to zero, that is, the first Hall 51 and the second Hall 52 are close together. In general, when the paired Halls gradually get closer, the anti-interference ability of the two gradually increases. Since the interference signal is not evenly distributed, when the spacing between the paired Halls is large, the intensity difference of the interference signal at the two Hall positions is also large; when the spacing between the paired Halls is gradually close (for example, the spacing between the two can be shortened to within 100μm), the intensity of the interference signal at the two Hall positions is almost equal, then, when the differential processing is performed later, the differential elimination can be made more thorough, thereby improving the sensing sensitivity of the Hall.

[0093] In one example, at least two groups of magnetic focusing blocks 60 are provided in two groups, namely, a first group of magnetic focusing blocks and a second group of magnetic focusing blocks. Alternatively, the first group of magnetic focusing blocks is provided above a pair of Halls (a first Hall 51 and a second Hall 52), and the second group of magnetic focusing blocks is provided below the pair of Halls.

[0094] In one example, specifically, the first group of magnetic focusing blocks includes a first magnetic focusing block 61, and the second group of magnetic focusing blocks includes a second magnetic focusing block 62 and a third magnetic focusing block 63. Figure 1A , Figure 1B and Figure 2 As shown, the first magnetic focusing block 61 is centrally symmetrically arranged above a pair of Halls consisting of a first Hall 51 and a second Hall 52, and the first magnetic focusing block 61 is respectively attached to the upper magnetic sensing surfaces of the pair of Halls; the second magnetic focusing block 62 and the third magnetic focusing block 63 are centrally symmetrically arranged between the pair of Halls and the insulating layer 40, and are respectively attached to the lower magnetic sensing surfaces of the pair of Halls.

[0095] In one example, further, on the upper magnetic sensing surfaces of the first Hall 51 and the second Hall 52, the first magnetic focusing block 61 is located in the middle area of ​​the pair of Halls (ie, the area on one side of the pair of Halls close to the center of the current row 30).

[0096] In one example, further, on the lower magnetic sensing surface of the first Hall 51 and the second Hall 52, the second magnetic focusing block 62 and the third magnetic focusing block 63 are arranged on both sides close to the pair of Halls. Figure 1B As shown, one end of the second magnetic block 62 away from the center of the current row 30 abuts against the inner side of the first side magnetic plate 22 of the magnetic yoke 20, and one end of the third magnetic block 63 away from the center of the current row 30 abuts against the inner side of the second side magnetic plate 23 of the magnetic yoke 20.

[0097] In one example, further, the first magnetic focusing block 61 , the second magnetic focusing block 62 and the third magnetic focusing block 63 are arranged to be symmetrical about the center of the current row 30 along the current direction and their plane projections coincide with the Hall center area of ​​the differential Hall current sensor 100 .

[0098] After the above two sets of magnetic blocks 60 are set, Figure 2 As shown, the magnetic yoke 20, the second magnetic concentrator block 62 and the third magnetic concentrator block 63 form an approximately closed magnetic concentrator structure. When current passes through the current row 30, the magnetic field generated by the current can be gathered by the magnetic concentrator structure to form a conductive magnetic circuit (see Figure 2 closed line segment).

[0099] In one example, there is a second gap between the second magnetic focusing block 62 and the third magnetic focusing block 63. Alternatively, the second gap may be larger than the first gap between the paired first Hall 51 and the second Hall 52. The specific distance value of the second gap may be designed according to the actual differential Hall current sensor 100. Alternatively, an insulating material is also filled in the second gap as a buffer layer.

[0100] The specific values ​​of the first gap and the second gap are determined after design according to the actual current measurement situation. That is to say, for current rows of different widths to be measured, matching first gaps and second gaps can be set. It should be noted that, for the differential Hall current sensor 100 provided in each embodiment of the present invention, since the magnetic yoke 20 and at least two groups of magnetic blocks 60 gather the current magnetic field and thus enhance the Hall-perceivable magnetic field strength, the specific values ​​of the different first gaps, second gaps, and the ratio of the first gap to the second gap are not the most critical design parameters that determine the performance of the differential Hall current sensor 100, and their effects on the performance indicators of the differential Hall current sensor 100, such as measurement sensitivity, measurement accuracy, measurement range, and anti-interference, are very weak and can be ignored.

[0101] After the above arrangement of the magnetic yoke 20 and the three magnetic focusing blocks (the first magnetic focusing block 61, the second magnetic focusing block 62 and the third magnetic focusing block 63), when the current to be measured is Figure 1A When the current direction shown in FIG. 1 (of course, the current direction may also be the opposite direction to the direction shown in the figure, then the directions of the subsequent magnetic field and magnetic field components are also reversed) enters the differential Hall current sensor 100, as shown in FIG. Figure 2 As shown, a magnetic field B is generated in the differential Hall current sensor 100, forming a closed conductive magnetic circuit around the current row 30 and two pairs of Halls (the first Hall 51 and the second Hall 52) (see Figure 2 The conducting magnetic circuit gathers the magnetic field generated by the current to be measured to the maximum extent, thereby maximizing the magnetic flux passing through the paired Hall, especially the magnetic flux in the direction perpendicular to the magnetic sensing surface of the Hall, thereby achieving the effect of improving its sensing sensitivity.

[0102] In one example, in order to further improve the magnetic focusing effect of the closed conductive magnetic circuit, the thickness of the Hall can be thinned alternatively. The thinner the thickness of the Hall, the more obvious the magnetic focusing effect of the closed conductive magnetic circuit. At the same time, the reduction in the thickness of the Hall also helps it to sense currents with weaker intensity, further expanding the perceptible range of the Hall, that is, expanding its measurement range. For example, when the Hall is prepared using a thin film transfer method and its thickness is less than or equal to 10μm, its sensitivity can be significantly improved.

[0103] In one example, at least two groups of magnetic focusing blocks 60 have a preset thickness. Alternatively, each group of magnetic focusing blocks in the at least two groups of magnetic focusing blocks 60 may have a different preset thickness. For example, the thickness of the first magnetic focusing block 61 may be different from or the same as the thickness of the second magnetic focusing block 62 and the third magnetic focusing block 63. For another example, if the second magnetic focusing block 62 and the third magnetic focusing block 63 constitute the second group of magnetic focusing blocks, then the thickness of the two should be set to be the same. At the same time, each magnetic focusing block should maintain a uniform thickness. Alternatively, the preset thickness of each magnetic focusing block in the at least two groups of magnetic focusing blocks 60 ranges from 100 to 1000 μm, and the specific value of the preset thickness can be set according to actual measurement requirements.

[0104] In one example, the cross-section of at least two groups of magnetic focusing blocks 60 also has a preset shape, which is a centrally symmetrical shape. For example, if the X-axis, Y-axis and origin are set on a plane, then when the center of the preset shape is located at the origin, it is symmetrical about both the X-axis and the Y-axis. Preferably, the cross-section shape of each magnetic focusing block in the at least two groups of magnetic focusing blocks 60 can be any one of a centrally symmetrical rhombus, square, rectangle, circle and ellipse. For example, in Example 1, Figure 1AAs shown, the first magnetic focusing block 61 is set to a diamond or square cross section, which has four corner points, and a group of two opposite corner points are respectively attached to the upper magnetic sensing surfaces of the first Hall 51 and the second Hall 52. At the same time, the second magnetic focusing block 62 and the third magnetic focusing block 63 are both set to square cross sections and are respectively attached to the lower magnetic sensing surfaces of the first Hall 51 and the second Hall 52.

[0105] In one example, alternatively, each of the at least two groups of magnetic concentrators 60 is prepared by photolithography and sputtering and then fixedly connected by bonding. The advantage of making at least two groups of magnetic concentrators 60 on the Hall by photolithography and sputtering is that the cross-sectional shape thereof can be symmetrical and the position thereof can be accurately affixed. Alternatively, the high magnetic permeability material can be pre-fabricated into an adapted cross-sectional shape by methods such as precision deposition and then fixedly mounted on the Hall by bonding. The symmetrical arrangement of the symmetrical cross-sections of the magnetic concentrators on the magnetic sensing surfaces of the paired Halls can effectively ensure that the signal gains of the paired Halls are the same, facilitating the subsequent differential signal processing.

[0106] In one example, if Figure 1A As shown, alternatively, the length of the first side magnetic focusing plate 22 and the second side magnetic focusing plate 23 of the magnetic yoke 20 is greater than the length of at least two groups of magnetic focusing blocks 60, so as to prevent the magnetic focusing blocks disposed inside the semi-enclosed structure of the magnetic yoke 20 from being affected by external interference and affecting the magnetic focusing effect. Preferably, the length of the first side magnetic focusing plate 22 and the second side magnetic focusing plate 23 exceeds the average length of the magnetic focusing blocks in at least two groups of magnetic focusing blocks 60 by 10% to 100%.

[0107] Through the above arrangement, when the differential Hall current sensor 100 of the first embodiment is connected in series with the current bus to be measured through the internal current bus 30, first refer to Figure 1A , assuming that the current direction is from bottom to top, the current generates a magnetic field B, and the magnetic field B generates magnetic field components in two directions perpendicular to the current direction; combined with Figure 2, the two magnetic field components perpendicular to the current direction are B1 and B2 respectively. The magnetic field component B1 is perpendicular to the magnetic induction surfaces of the two Halls, defined as the vertical magnetic field component B1, and the magnetic field components of the vertical magnetic field component B1 on the two paired Halls are the same in value but opposite in direction (vertically downward on the first Hall 51 and vertically upward on the second Hall 52); the magnetic field component B2 is parallel to the magnetic induction surfaces of the two Halls, defined as the parallel magnetic field component B2. The magnetic yoke 20 and the three magnetic concentrators (the first magnetic concentrator 61, the second magnetic concentrator 62 and the third magnetic concentrator 63) gather the magnetic field to form a closed conductive magnetic circuit. The function of the closed conductive magnetic circuit is to increase the magnetic flux by gathering the magnetic field to enhance the vertical magnetic field component B1, and on the other hand, the parallel magnetic field component B2 can be fully or partially weakened by the staggered arrangement of the three magnetic concentrators up and down, so that all or part of the parallel magnetic field component B2 is turned to the direction of the vertical magnetic field component B1 and superimposed in the same direction with the vertical magnetic field component B1, which can further enhance the magnetic flux in the vertical direction. Increasing the magnetic flux can significantly improve the sensing sensitivity of the differential Hall current sensor 100 . In various embodiments of the present invention, the magnetic flux density can be increased by more than 4 times compared with a traditional differential Hall sensor.

[0108] Example 2

[0109] Based on the above embodiment 1, the relative position of each group of magnetic focusing blocks in at least two groups of magnetic focusing blocks 60 can also be adjusted. Figure 3 , shows the cross-sectional structure of the differential Hall current sensor 100' of Example 2. Compared with Example 1, the basic structural composition is the same. The specific configuration of each part can be referred to Figure 1A and Figure 1B , no further details will be given here, and only the settings that are different from Example 1 will be described below.

[0110] In the differential Hall current sensor 100 ′ of the second embodiment, Figure 1B Compared with the differential Hall current sensor 100 of the embodiment 1 shown, the first group of magnetic focusing blocks (including the first magnetic focusing block 61) in the embodiment 1 is changed from being arranged above the paired Halls (the first Hall 51 and the second Hall 52) to being arranged below them. At the same time, the second group of magnetic focusing blocks (including the second magnetic focusing block 62 and the third magnetic focusing block 63) is changed from being arranged below the paired Halls to being arranged above them.

[0111] In one example, specifically, in conjunction with Figure 1B and Figure 3As shown, the first group of magnetic focusing blocks includes a first magnetic focusing block 61 centrally symmetrically arranged between at least one pair of Hall 50 (for example, the first Hall 51 and the second Hall 52) and the insulating layer 40 (which may also include a buffer layer), and the first magnetic focusing block 61 is respectively attached to the lower magnetic sensing surface of at least one pair of Hall 50. Preferably, as Figure 3 As shown, the first magnetic focusing block 61 is embedded in the insulating layer 40. The second group of magnetic focusing blocks includes a second magnetic focusing block 62 and a third magnetic focusing block 63 which are centrally symmetrically arranged on at least one pair of Hall 50; the second magnetic focusing block 62 and the third magnetic focusing block 63 are located in the cavity of the magnetic yoke 20, and the second magnetic focusing block 62 and the third magnetic focusing block 63 are respectively attached to the upper magnetic sensing surface of at least one pair of Hall 50.

[0112] In one example, further, the first magnetic focusing block 61 is located in the middle area of ​​the first Hall 51 and the second Hall 52, and the second magnetic focusing block 62 and the third magnetic focusing block 63 are arranged on both sides close to the two Halls. Preferably, the end of the second magnetic focusing block 62 away from the center of the current row 30 is abutted against the inner side of the first side magnetic focusing plate 22 of the magnetic yoke 20, and the end of the third magnetic focusing block 63 away from the center of the current row 30 is abutted against the inner side of the second side magnetic focusing plate 23 of the magnetic yoke 20.

[0113] In one example, further, the first magnetic focusing block 61, the second magnetic focusing block 62 and the third magnetic focusing block 63 are arranged to be symmetrical about the center of the current row 30 and their planar projections coincide with the Hall center area of ​​the differential Hall current sensor, which is the center area of ​​the Hall on its magnetic sensing surface.

[0114] In one example, further, there is a first gap between the first Hall 51 and the second Hall 52 , and the first gap is set to a predetermined distance or equal to zero; there is a second gap between the second magnetic focusing block 62 and the third magnetic focusing block 63 .

[0115] like Figure 3 As shown, when the current to be measured generates a magnetic field B (the same direction as the current and magnetic field listed in Example 1), a closed conductive magnetic circuit is formed around the current row 30 and the two paired Halls (the first Hall 51 and the second Hall 52) (see Figure 3 Since the upper and lower positions of the two groups of staggered magnetic blocks 60 are completely opposite to those in Example 1, the magnetic lines of force of the conductive magnetic circuit are the same as those in Example 1 (see Figure 2), the vertical magnetic field component B1 generated on the magnetic sensing surfaces of the two paired Halls is changed from a convex shape to a concave shape, and the direction of the vertical magnetic field component B1 generated on the magnetic sensing surfaces of the two paired Halls is correspondingly opposite to the direction of the vertical magnetic field component B1 of Example 1. That is to say, taking the first Hall 51 as an example, under the conductive magnetic circuit in Example 1, the vertical magnetic field component B1 on its magnetic sensing surface is vertically downward, while under the conductive magnetic circuit in Example 2, the vertical magnetic field component B1 on its magnetic sensing surface is vertically upward, and the direction of the parallel magnetic field component B2 on its magnetic sensing surface is the same as that of Example 1.

[0116] Alternatively, other structural settings in Example 2, the structural settings of the Hall, etc. can be set with reference to the various examples or combinations of the examples given in Example 1, and will not be repeated here.

[0117] Example 3

[0118] On the basis of the above-mentioned embodiment 1 or embodiment 2, the logarithm of the paired Hall is expanded to obtain the structure of the differential Hall current sensor 200 of embodiment 3. As described in the above-mentioned embodiments, at least two Halls 50 include at least one pair of Halls located in the semi-enclosed structure of the yoke 20 and centrally symmetrically arranged on both sides of the upper surface of the insulating layer 40. For example, in embodiment 1, the number of at least two Halls 50 is 2 and a pair of Halls (i.e., the first Hall 51 and the second Hall 52) is formed. Then, based on the pair of Halls, we can set two, three or more pairs of Halls in the semi-enclosed structure of the yoke 20 according to the actual measurement scenario.

[0119] See also Figure 4 , shows the structure of a differential Hall current sensor 200 using two pairs of Halls according to Embodiment 3, including a first pair of Halls (a first Hall 51 and a second Hall 52 ) and a second pair of Halls (a third Hall 53 and a fourth Hall 54 ).

[0120] In one example, a magnetic yoke 20 is disposed on the sensing portion 11 of the same substrate 10, and the first pair of Halls and the second pair of Halls are both disposed inside the semi-enclosed structure of the magnetic yoke 20. First, each pair of Halls in the two pairs of Halls has a structure of three magnetic concentrators as described in Example 1 or Example 2. Figure 4 The paired Halls shown are the paired Halls of Example 1, that is, Figure 1A , Figure 1B and Figure 2 The first magnetic concentrator block 61, the second magnetic concentrator block 62 and the third magnetic concentrator block 63 are shown. Then, each pair of Halls are arranged parallel to each other on the insulating layer 40, and the first pair of Halls and the second pair of Halls are arranged at intervals from each other. When the number of pairs of Halls continues to increase, they can be arranged in sequence according to this arrangement.

[0121] Alternatively, the structural dimensions of the magnetic yoke 20 of Example 3 can be adjusted with reference to the arrangement of Example 1 and Example 2 and in combination with the number of paired Halls. The arrangement of the structure and relative positions of the paired Halls and the various magnetic focusing blocks attached to their magnetic sensing surfaces, such as the first spacing between the paired Halls, the second spacing between the second magnetic focusing block 62 and the third magnetic focusing block 63, the cross-sectional shape of the magnetic focusing blocks, etc., can also be adjusted with reference to the arrangement of Example 1 and Example 2, and will not be repeated here.

[0122] Example 4

[0123] See also Figure 5 , shows the structure of the differential Hall current sensor 300 of Example 4. Compared with Example 1 or Example 2, the basic structural composition is the same, and the specific settings of each part are not repeated. The following only describes the settings that are different from Example 1 or Example 2.

[0124] In the differential Hall current sensor 300 of the fourth embodiment, an integrated Hall element is used to replace the Hall bare chip in the first embodiment. Figure 1A The first magnetic concentrator block 61, the second magnetic concentrator block 62 and the third magnetic concentrator block 63 are arranged in the manner shown in the figure, and then the magnetic concentrator block 61, the second magnetic concentrator block 62 and the third magnetic concentrator block 63 are arranged as shown in the figure. Figure 5 The first Hall 51 a and the second Hall 52 a shown in the figure both use integrated Hall elements.

[0125] Correspondingly, the Hall chip circuit board 41 can be placed below the paired first Hall 51a and second Hall 52a, for example, alternatively placed on the insulating layer 40, and the respective pins of the first Hall 51a and the second Hall 52a are directly soldered to the Hall chip circuit board 41; and then electrically connected to the circuit unit 12 for signal processing and signal output.

[0126] In one example, alternatively, in order to reduce the size of the package structure of the differential Hall current sensor 300 , two pairs of integrated Hall elements (the first Hall 51 a and the second Hall 52 a ) may be placed close together, and the first gap between the two is equal to zero.

[0127] In one example, alternatively, one may also use Figure 3 The arrangement of the first magnetic focusing block 61 , the second magnetic focusing block 62 and the third magnetic focusing block 63 in the second embodiment shown constitutes the differential Hall current sensor 300 of the third embodiment.

[0128] Example 5

[0129] On the basis of the above-mentioned embodiment 4, the structure of the differential Hall current sensor 300 ′ of embodiment 5 is obtained by expanding the number of pairs of integrated Hall elements.

[0130] See also Figure 6 , the scheme of expanding the number of Hall pairs is the same as that of Example 3, taking two pairs of Hall as an example, and selecting integrated Hall elements in the same way as Example 4, including a first pair of integrated Hall elements (first Hall 51a and second Hall 52a) and a second pair of integrated Hall elements (third Hall 53a and fourth Hall 54a). The specific setting method of each pair of integrated Hall elements is the same as that of Example 4, and the setting method of two adjacent pairs of integrated Hall elements is the same as that of Example 3, which will not be repeated here. Of course, three, four or more pairs of integrated Hall elements can be further set.

[0131] In one example, after the differential Hall current sensor based on the above embodiments is manufactured, the interference between the paired Hall sensors can be eliminated by signal differentiation, ensuring that the Hall sensors have high and stable sensing sensitivity. The principle of signal differentiation of paired Hall sensors is briefly described below.

[0132] Taking the differential Hall current sensor 100 of the above-mentioned embodiment 1 as an example, it is provided with a pair of Halls, namely Figure 1A , Figure 1B and Figure 2 The first Hall 51 and the second Hall 52 are shown. Figure 2 Theoretically, when the current to be measured is detected, under the action of magnetic field B, two magnetic field components in two directions are generated on the magnetic sensing surfaces of the two Hall sensors. One of them is the vertical magnetic field component B1 perpendicular to the magnetic sensing surface of the Hall sensor, which is also the magnetic field component that the Hall sensor can sense; the other is the parallel magnetic field component B2 perpendicular to the direction of the current to be measured but parallel to the magnetic sensing surface of the Hall sensor, which is the magnetic field component that cannot be sensed by the Hall sensor.

[0133] Since the two Halls are arranged symmetrically relative to the current row 30 in the direction of the current, for each Hall, the vertical magnetic field component B1 is equal in magnitude but opposite in direction; at the same time, the height of each Hall relative to the current row 30 is consistent. At this time, on each Hall, the proportional relationship between the vertical magnetic field component B1 and the parallel magnetic field component B2 is also fixed.

[0134] At this time, let B2 = k1*B1, k1 is the magnetic field proportional coefficient, then the measured current I0∝B1 can be obtained.

[0135] The vertical magnetic field components B1 acting on the first Hall 51 and the second Hall 52 are the same in magnitude but opposite in direction, so the output voltages of the two in the horizontal direction are:

[0136] V 水平-1 = -V 水平-2 = a*B1; where V水平-1 represents the horizontal voltage generated by the vertical magnetic field component B1 on the first Hall 51, V 水平-2 represents the horizontal voltage generated by the vertical magnetic field component B1 on the second Hall 52, a is a first proportional constant, and the value of a is related to the inherent parameters of the Hall itself (such as the structural size of the Hall, the material used to make the Hall, etc.).

[0137] The parallel magnetic field components B2 acting on the first Hall 51 and the second Hall 52 are of the same magnitude and direction, and the output voltages of the two in the vertical direction are:

[0138] V 垂直-1 = -V 垂直-2 = b*B2; where V 垂直-1 represents the vertical voltage generated by the parallel magnetic field component B2 on the first Hall 51, -V 垂直-2 It represents the vertical voltage generated by the parallel magnetic field component B2 on the second Hall 52. b is the second proportional constant, which is similar to the first proportional constant a. The value of b is related to the inherent parameters of the Hall itself (such as the structural size of the Hall, the material used to make the Hall, etc.).

[0139] When the interference magnetic field signal C is added, the total output voltages of the first Hall 51 and the second Hall 52 are:

[0140] The total output voltage of the first Hall 51, V1 = a*B1 + b*B2 + C;

[0141] The total output voltage of the second Hall 52, V2 = -a*B1 - b*B2 + C;

[0142] Further calculate the differential signal between V1 and V2 , the calculation formula is as follows:

[0143] .

[0144] It can be seen that the difference eliminates the interference. At the same time, it is known that B2 = k1*B1, then we can get:

[0145] Differential signaling , can be set , where K is the coefficient of the current flowing through the current block and the Hall voltage, which can be determined by calibrating the Hall. At the same time, the first proportional constant a, the second proportional constant b, and the magnetic field proportional coefficient k1 are all Hall intrinsic variables, which are determined by their factory configuration. In other words, as long as the differential signal is obtained By calibrating the coefficient K between the current flowing through the current bus and the Hall voltage, the current value I0 of the current to be measured input into the current bus 30 can be calculated.

[0146] In one example, since at least two sets of magnetic blocks 60 used in the actual differential Hall current sensor (taking the differential Hall current sensor 100 of Example 1 as an example) may have installation position errors during their installation, it is easy to cause deviations in the vertical magnetic field component or the horizontal magnetic field component for the signal gain coefficient of each Hall. In order to correct this deviation, it is usually necessary to perform differential signal The specific calibration steps are as follows (taking the pair of Halls set in the above embodiment 1 as an example):

[0147] At this time, the vertical magnetic field components B1 acting on the first Hall 51 and the second Hall 52 are the same in magnitude but opposite in direction. Considering the installation position error of the first magnetic focusing block 61, the second magnetic focusing block 62 or the third magnetic focusing block 63, the output voltages of the two in the horizontal direction are respectively:

[0148] V 水平-1 = a1*B1;

[0149] V 水平-2 = -a2*B2;

[0150] Among them, V 水平-1 represents the horizontal voltage generated by the vertical magnetic field component B1 on the first Hall 51, V 水平-2 It represents the horizontal voltage generated by the vertical magnetic field component B1 on the second Hall 52. a1 and a2 are the first proportional constants corresponding to the first Hall 51 and the second Hall 52 respectively after adding the installation position error. When the differential Hall current sensor 100 is assembled, the value of the above-mentioned first proportional constant is also determined.

[0151] Similarly, when the parallel magnetic field component B2 acts on the first Hall 51 and the second Hall 52 respectively, the output voltages of the two in the horizontal direction are respectively:

[0152] V 垂直-1 = b1*B2;

[0153] V 垂直-2 = -b2*B2;

[0154] Among them, V 垂直-1 V represents the vertical voltage generated by the parallel magnetic field component B2 on the first Hall 51. 垂直-2 It represents the vertical voltage generated by the parallel magnetic field component B2 on the second Hall 52. b1 and b2 are the second proportional constants corresponding to the first Hall 51 and the second Hall 52 respectively after adding the installation position error. When the differential Hall current sensor 100 is assembled, the value of the above second proportional constant is also determined.

[0155] When the interference magnetic field signal C is added, the total output voltages of the first Hall 51 and the second Hall 52 are:

[0156] The total output voltage of the first Hall 51, V1 = a1*B1 + b1*B2 + C;

[0157] The total output voltage of the second Hall 52, V2 = -a2*B1 - b2*B2 + C;

[0158] Further calculate the differential signal between V1 and V2 , the calculation formula is as follows:

[0159] .

[0160] It can be seen that the difference eliminates the interference. At the same time, it is known that B2 = k1*B1, then we can get:

[0161] Differential signaling , can be set , where K is the coefficient of the current flowing through the current block and the Hall voltage, which can be determined by calibrating the Hall. At the same time, the first known proportional constants a1 and a2, the second proportional constants b1 and b2, and the magnetic field proportional coefficient k1 are all Hall intrinsic variables, which are determined by their factory configuration. In other words, as long as the differential signal is obtained By calibrating the coefficient K between the current flowing through the current bus and the Hall voltage, the current value I0 of the current to be measured input into the current bus 30 can be calculated.

[0162] According to another aspect of the present invention, an embodiment of the present invention further provides a method for manufacturing a differential Hall current sensor, which is used to manufacture the differential Hall current sensor described in the above aspects and embodiments, Figure 1A-Figure 6 As shown, the manufacturing method includes:

[0163] manufacturing a substrate 10;

[0164] A yoke 20 is manufactured, which has a semi-enclosed structure consisting of a bottom surface and two side surfaces located on the same side of the bottom surface, and the bottom surface of the semi-enclosed structure is bonded to the substrate 10;

[0165] Manufacturing a device frame (not shown), arranging the current bar 30 in the device frame, and bonding the current bar 30 in the device frame to the cavity of the semi-enclosed structure and allowing both ends of the current bar 30 to extend from the semi-enclosed structure;

[0166] Manufacturing an insulating layer 40 (which may also include a buffer layer filled in the magnetic concentrator layer or used to set the Hall chip circuit board 41), the insulating layer 40 is arranged on the upper surface of the current row 30 and is located in the cavity;

[0167] At least two Hall electrodes 50 are symmetrically arranged on both sides of the upper surface of the insulating layer 40 along the current direction;

[0168] At least two groups of magnetic focusing blocks 60 are manufactured, and each group of magnetic focusing blocks of the at least two groups of magnetic focusing blocks 60 is disposed close to the magnetic sensing surfaces of at least two Halls 50;

[0169] At least two groups of magnetic concentrators 60 and the magnetic yoke 20 form a conducting magnetic circuit, through which the magnetic field components of the current magnetic field in the direction parallel to the magnetic sensing surfaces of at least two Halls 50 are deflected into magnetic field components in the direction perpendicular to the magnetic sensing surfaces;

[0170] The coefficient K between the current flowing through the current row of each pair of Halls in at least two Halls 50 and the Hall voltage is obtained by calibration measurement.

[0171] In one example, when making the insulating layer 40 (including the buffer layer filled in the magnetic block layer or used to set the Hall chip circuit board 41), the surface of the insulating layer or the buffer layer should be controlled by process to be flat and free of holes for subsequent growth or transfer of Hall.

[0172] In one example, alternatively, at least two Hall electrodes 50 are transferred to the insulating layer 40 (including a buffer layer filled in the magnetic block layer or used to set the Hall chip circuit board 41) using a semiconductor process for material growth or an already grown Hall functional film, and the positions of at least two Hall electrodes 50 are adjusted to achieve the installation positions required by the above aspects and Examples 1 to 5.

[0173] In one example, by adjusting the specific process of the above manufacturing method or the specific details of manufacturing a certain component, it is possible to manufacture the differential Hall current sensor of the above embodiments 1 to 5. For the structural differences of different embodiments in the manufacturing process, please refer to the description of the above embodiments, which will not be repeated here.

[0174] The differential Hall current sensor and the manufacturing method thereof provided by the embodiments of the present invention have at least one or part of the following advantages:

[0175] (1) The differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention gather the magnetic field generated by the current row to be measured through the magnetic yoke and the magnetic concentrator to form a conductive magnetic circuit, thereby increasing the magnetic flux density, enhancing the magnetic field strength that can be perceived by the Hall, and improving the measurement sensitivity;

[0176] (2) The differential Hall current sensor and its manufacturing method provided in the embodiments of the present invention use two groups of staggered magnetic concentrators to deflect the magnetic field component that cannot be sensed by the Hall current to the direction of the magnetic field that can be sensed by the Hall current in whole or in part, thereby further enhancing the perceptible magnetic field strength.

[0177] (3) The differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention ensure the alignment accuracy of the relative position of the internal Hall and the current row to be measured by connecting the preset current row in series with the current row to be measured, and have good consistency, thereby reducing the measurement error;

[0178] (4) The differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention set the Hall on a preset current row, so as to avoid the spacing between the Halls on both sides being affected by the increase in the width of the actual current row to be measured. The spacing between the Halls on both sides can be reduced to zero, thereby reducing the size of the packaging structure and helping to improve the Hall anti-interference performance.

[0179] (5) The gaps between the magnetic collecting blocks and the gaps between the paired Halls of the differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention can be designed accordingly according to the actual width of the current row to be measured and the measurement requirements without affecting the overall magnetic collecting effect, and are generally applicable to the measurement of currents in various ranges;

[0180] (6) The differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention can flexibly arrange multiple pairs of Halls and the magnetic concentrators attached to their magnetic sensing surfaces, and can also flexibly design the shape of the magnetic concentrators. The mature processing method is used, the process is simple, and no additional manufacturing cost is added.

[0181] (7) The differential Hall current sensor and the manufacturing method thereof provided in the embodiments of the present invention arrange the Hall electrodes symmetrically in pairs on the current row, eliminate interference signals in the measurement process through the differential circuit, improve the measurement sensitivity and accuracy, and are particularly conducive to sensing extremely small current values, thereby expanding the range of the differential Hall current sensor.

[0182] Although some embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. A differential Hall current sensor, characterized in that: The differential Hall current sensor comprises: substrate; A yoke having a semi-enclosed structure consisting of a bottom surface and two side surfaces located on the same side of the bottom surface, wherein the bottom surface of the semi-enclosed structure is bonded to the substrate; a current bar, the current bar being placed in the cavity of the semi-enclosed structure and allowing both ends of the current bar to extend out of the semi-enclosed structure; an insulating layer disposed on an upper surface of the current bank and located in the cavity; At least two Hall elements are symmetrically arranged on both sides of the upper surface of the insulating layer along the current direction; At least two groups of magnetic focusing blocks, each group of the at least two groups of magnetic focusing blocks is arranged close to the magnetic sensing surfaces of the at least two Halls, at least one group of the at least two groups of magnetic focusing blocks is arranged in the cavity of the magnetic yoke and one end of each of the magnetic focusing blocks away from the center of the current row is close to the magnetic yoke; The at least two groups of magnetic focusing blocks and the magnetic yoke form a conducting magnetic circuit to deflect the magnetic field component of the current magnetic field in a direction parallel to the magnetic induction surface into a magnetic field component in a direction perpendicular to the magnetic induction surface.

2. The differential Hall current sensor according to claim 1, characterized in that: The magnetic yoke is formed in one piece, and the semi-enclosed structure is composed of a bottom magnetic focusing plate and a first side magnetic focusing plate and a second side magnetic focusing plate located at both ends of the same side of the bottom magnetic focusing plate. The cavity is formed by surrounding the bottom magnetic focusing plate, the first side magnetic focusing plate and the second side magnetic focusing plate.

3. The differential Hall current sensor according to claim 2, characterized in that: The current row extends from both sides of the cavity where no side magnetic concentrator plates are provided and is connected in series with the external current row to be measured, and the magnetic field generated by the current row to be measured is gathered by the magnetic yoke; An IC circuit part is also arranged on the substrate, and the at least two Hall sensors output measurement signals after being differentiated by the IC circuit part.

4. The differential Hall current sensor according to claim 3, characterized in that: The at least two Halls include at least one pair of Halls located in a semi-enclosed structure of the magnetic yoke and centrally symmetrically arranged on both sides of the upper surface of the insulating layer, and one pair of Halls in the at least one pair of Halls includes a first Hall and a second Hall arranged oppositely.

5. The differential Hall current sensor according to claim 4, characterized in that: The at least two groups of magnetic focusing blocks are two groups of magnetic focusing blocks, and the two groups of magnetic focusing blocks include a first group of magnetic focusing blocks and a second group of magnetic focusing blocks; The first group of magnetic focusing blocks includes a first magnetic focusing block centrally symmetrically arranged above each pair of Halls in the at least one pair of Halls, the first magnetic focusing block is respectively attached to the upper magnetic sensing surface of each pair of Halls, and the first magnetic focusing block is located in the middle area of ​​the two Halls of each pair of Halls; The second group of magnetic focusing blocks includes a second magnetic focusing block and a third magnetic focusing block which are centrally symmetrically arranged between each pair of Halls in the at least one pair of Halls and the insulating layer, the second magnetic focusing block and the third magnetic focusing block are located in the cavity of the magnetic yoke, the second magnetic focusing block and the third magnetic focusing block are respectively attached to the lower magnetic sensing surface of each pair of Halls, the end of the second magnetic focusing block away from the center of the current row is attached to the inner side of the magnetic focusing plate on the first side of the magnetic yoke, and the end of the third magnetic focusing block away from the center of the current row is attached to the inner side of the magnetic focusing plate on the second side of the magnetic yoke; The first magnetic concentrator block, the second magnetic concentrator block and the third magnetic concentrator block are arranged symmetrically about the center of the current row, and their plane projections coincide with the Hall center area of ​​the differential Hall current sensor; In each pair of the at least one pair of Halls, there is a first gap between the first Hall and the second Hall, and the first gap is set to a predetermined distance or equal to zero; A second gap is provided between the second magnetic focusing block and the third magnetic focusing block.

6. The differential Hall current sensor according to claim 4, characterized in that: The at least two groups of magnetic focusing blocks are two groups of magnetic focusing blocks, and the two groups of magnetic focusing blocks include a first group of magnetic focusing blocks and a second group of magnetic focusing blocks; The first group of magnetic focusing blocks includes a first magnetic focusing block centrally symmetrically arranged between each pair of Halls in the at least one pair of Halls and the insulating layer, the first magnetic focusing block is respectively attached to the lower magnetic sensing surface of each pair of Halls, and the first magnetic focusing block is located in the middle area of ​​the two Halls of each pair of Halls; The second group of magnetic focusing blocks includes a second magnetic focusing block and a third magnetic focusing block which are centrally symmetrically arranged above each pair of Halls in the at least one pair of Halls; the second magnetic focusing block and the third magnetic focusing block are located in the cavity of the magnetic yoke, the second magnetic focusing block and the third magnetic focusing block are respectively attached to the upper magnetic induction surface of each pair of Halls, the end of the second magnetic focusing block away from the center of the current row is attached to the inner side of the magnetic focusing plate on the first side of the magnetic yoke, and the end of the third magnetic focusing block away from the center of the current row is attached to the inner side of the magnetic focusing plate on the second side of the magnetic yoke; The first magnetic concentrator block, the second magnetic concentrator block and the third magnetic concentrator block are arranged symmetrically about the center of the current row, and their plane projections coincide with the Hall center area of ​​the differential Hall current sensor; In each pair of the at least one pair of Halls, there is a first gap between the first Hall and the second Hall, and the first gap is set to a predetermined distance or equal to zero; A second gap is provided between the second magnetic focusing block and the third magnetic focusing block.

7. The differential Hall current sensor according to any one of claims 1 to 6, characterized in that: When any one of the at least one pair of Hall elements is an integrated Hall element, the pins of the integrated Hall element are directly welded to the Hall element circuit provided on the substrate and then connected to the signal processing circuit provided on the substrate; or, When any one of the at least one pair of Hall sensors is a bare Hall chip, the bare Hall chip is directly placed in the cavity of the magnetic yoke, connected to the Hall chip circuit through metal wires, and then connected to the signal processing circuit arranged on the substrate.

8. The differential Hall current sensor according to claim 7, characterized in that: The at least one pair of Halls comprises at least two pairs of Halls arranged in parallel on the insulating layer, wherein two adjacent pairs of Halls in the at least two pairs of Halls are arranged at intervals.

9. The differential Hall current sensor according to claim 8, characterized in that: The cross-sectional shape of any one of the at least two groups of magnetic concentrating blocks is a centrally symmetrical shape, and the centrally symmetrical shape is any one of a rhombus, a square, a rectangle, a circle, and an ellipse; The materials of the at least two groups of magnetic concentrators and the magnetic yoke are high magnetic permeability materials that are non-magnetic, and the high magnetic permeability materials are any one of ferrite, soft magnet, and nano-magnetic crystal; The material of each Hall in the at least two Halls is a Hall material, and the Hall material is any one of GaAs, InSb, and InAs.

10. A method for manufacturing a differential Hall current sensor, for manufacturing the differential Hall current sensor according to any one of claims 1 to 9, the manufacturing method comprising: manufacturing substrates; manufacturing a yoke having a semi-enclosed structure consisting of a bottom surface and two side surfaces located on the same side of the bottom surface, wherein the bottom surface of the semi-enclosed structure is bonded to the substrate; Manufacturing a device frame, arranging a current bus in the device frame, and bonding the current bus in the device frame into the cavity of the semi-enclosed structure and allowing both ends of the current bus to extend out of the semi-enclosed structure; manufacturing an insulating layer disposed on an upper surface of the current bus and in the cavity; At least two Hall electrodes are symmetrically arranged on both sides of the upper surface of the insulating layer along the current direction; At least two groups of magnetic focusing blocks are manufactured, each group of the at least two groups of magnetic focusing blocks is arranged close to the magnetic sensing surfaces of the at least two Halls, at least one group of the at least two groups of magnetic focusing blocks is arranged in the cavity of the magnetic yoke and one end of each of the magnetic focusing blocks away from the center of the current row is close to the magnetic yoke; The at least two groups of magnetic focusing blocks and the magnetic yoke form a conducting magnetic circuit, and the conducting magnetic circuit deflects the magnetic field component of the current magnetic field in the direction parallel to the magnetic sensing surfaces of the at least two Halls into a magnetic field component in the direction perpendicular to the magnetic sensing surfaces; The coefficient of the current flowing through each pair of Halls constituting a pair of at least two Halls and the Hall voltage is obtained by calibration measurement.

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