Current sensing chip and method of manufacture

Abstract

The application provides a current sensing chip and a manufacturing method, and relates to the technical field of sensing chips.The magnetic core, the coil and the current-carrying conductor of the current sensing chip are formed on the same semiconductor substrate based on a micro-electro-mechanical system process, the magnetic core is composed of an independent magnetic core made of a soft magnetic material or a composite structure magnetic core, and the current-carrying conductor is arranged in a region close to the magnetic core; the coil comprises at least one set of excitation coils and at least one set of induction coils, the excitation coils and the induction coils are both wound on the magnetic core, and the excitation coils and the induction coils can be multiplexed as feedback coils; when the current-carrying conductor is connected to a current to be measured, the magnetic field generated around the current-carrying conductor by the current to be measured acts on the magnetic core to cause the magnetic flux to change, and the measurement of the current to be measured is realized by detecting the output signal of the induction coil or the feedback coil. The application can improve the anti-interference capability, can realize chip-level closed-loop current detection, has high detection precision, a wide range, and can significantly reduce the volume and manufacturing cost of the sensor.

Description

Technical Field

[0001] This invention relates to the field of sensor chip technology, and more specifically to a current sensing chip and its manufacturing method. Background Technology

[0002] In power systems, current detection is a crucial method for monitoring the status of power equipment. Small current sensors are primarily used to measure weak currents such as leakage current, for example, in monitoring leakage current in distribution network insulation lines and monitoring the insulation status of substation equipment. Installing small current sensors on critical facilities and equipment such as transmission lines, cables, transformers, and circuit breakers can promptly detect abnormal current fluctuations and provide early warnings of potential faults, thereby ensuring the safe and stable operation of the power grid. Furthermore, with the increasing proportion of distributed energy resources connected to the grid, the demand for AC / DC small current sensors in new energy equipment such as photovoltaic inverters and charging piles is growing, and current sensors are developing towards higher precision, miniaturization, and intelligence.

[0003] Current sensors include resistive shunts, Rogowski coils, current transformers, Hall effect current sensors, magnetoresistive current sensors, magnetically modulated current sensors, and fiber optic current sensors. Resistive shunts lack electrical isolation, while Rogowski coils and current transformers are only suitable for AC current measurement. Fiber optic current sensors offer high accuracy but suffer from poor temperature stability and vibration interference resistance. Hall effect current sensors, magnetoresistive current sensors, and magnetically modulated current sensors are currently the three most widely used types of current sensors.

[0004] Existing Hall effect current sensors and magnetoresistive current sensors still need further improvement in terms of sensitivity, measurement accuracy, and temperature stability, and cannot meet the requirements for precise measurement of small currents in the microampere to milliampere range. Magnetic modulation current sensors, on the other hand, offer high accuracy and good temperature stability, giving them unique advantages in detecting weak currents in the milliampere or microampere range. Traditional magnetic modulation current sensors are made using enameled wire wound magnetic cores, which suffers from uneven coil winding, poor consistency, large size, and high power consumption, hindering the integration and intelligent development of small current sensors. Summary of the Invention

[0005] To address the aforementioned technical deficiencies, this invention provides a current sensing chip and its manufacturing method.

[0006] The current sensing chip provided by the present invention includes: a magnetic core, a coil, and a current-carrying conductor. The magnetic core includes at least one independent magnetic core or a composite structure magnetic core composed of soft magnetic material. The current-carrying conductor includes at least one conductor disposed in a region close to the magnetic core or wound around the magnetic core. The coil includes at least one set of induction coils, or includes at least one set of induction coils and at least one set of excitation coils. Both the excitation coils and the induction coils are wound around the magnetic core, and both the excitation coils and the induction coils can be reused as feedback coils.

[0007] When a current-carrying conductor is connected to a current to be measured, the magnetic field generated by the current to be measured around the conductor acts on the magnetic core, causing a change in magnetic flux. The current to be measured is measured by detecting the output signal of the induction coil or feedback coil.

[0008] The magnetic core, coil, and current-carrying conductor are formed on the same semiconductor substrate, and the formation method includes:

[0009] A half-coil cavity and a half-current-carrying conductor cavity are formed on the bottom substrate;

[0010] A half-coil cavity and a half-current-carrying conductor cavity are formed on the top substrate;

[0011] A magnetic core cavity, a coil connection structure cavity, and a current-carrying conductor connection structure cavity are formed on a bottom substrate or a top substrate; or, a magnetic core cavity, a coil connection structure cavity, and a current-carrying conductor connection structure cavity are formed on an intermediate substrate.

[0012] A magnetic core is formed by filling the cavity with magnetic material.

[0013] By combining the bottom substrate and the top substrate, or by combining the bottom substrate, the intermediate substrate and the top substrate, a closed magnetic core cavity, a three-dimensional helical coil cavity and a connected current-carrying conductor cavity can be formed.

[0014] A three-dimensional spiral coil is formed by filling a three-dimensional spiral coil cavity with a wound magnetic core, and a conductor material is formed by filling a connected current-carrying conductor cavity with conductor material.

[0015] In this embodiment of the invention, the magnetic core is ring-shaped, racetrack-shaped, rectangular, or rod-shaped.

[0016] In this embodiment of the invention, the racetrack-shaped magnetic core has a symmetrical first magnetic axis and a symmetrical second magnetic axis, a symmetrical third magnetic axis and a fourth magnetic axis;

[0017] At least one set of excitation coils is wound on the first magnetic shaft, and at least one set of induction coils or at least one set of feedback coils is wound on the second magnetic shaft;

[0018] The current-carrying conductor is disposed through the cavity of the racetrack-shaped magnetic core, or around the third or fourth magnetic axis of the racetrack-shaped magnetic core.

[0019] In this embodiment of the invention, there are two current-carrying conductors, which are respectively wrapped around the third magnetic axis and the fourth magnetic axis of the racetrack-shaped magnetic core, or are disposed through the cavity of the racetrack-shaped magnetic core.

[0020] In this embodiment of the invention, there are two current-carrying conductors. One current-carrying conductor is disposed through the cavity of the racetrack-shaped magnetic core, and the other current-carrying conductor is disposed in the region near the magnetic core and parallel to the magnetic core.

[0021] In this embodiment of the invention, there are two rod-shaped magnetic cores;

[0022] The current-carrying conductor is placed between the two rod-shaped magnetic cores and is parallel to the two rod-shaped magnetic cores.

[0023] In this embodiment of the invention, both the excitation coil and the induction coil are three-dimensional structures, and the three-dimensional excitation coil and the induction coil are wound on the magnetic core in a spiral manner.

[0024] In this embodiment of the invention, the magnetic core is a thin strip magnetic core, a thick film magnetic core, or a composite structure magnetic core made of soft magnetic material, wherein the soft magnetic material is permalloy, amorphous alloy, or nanocrystalline alloy.

[0025] In this embodiment of the invention, the magnetic core is a composite magnetic core made of two soft magnetic materials with different permeabilities;

[0026] The feedback coil is wound around a core made of a soft magnetic material with the first permeability;

[0027] The excitation coil and the induction coil are wound on a magnetic core made of a soft magnetic material with a second permeability.

[0028] In this embodiment of the invention, when the induction coil is reused as a feedback coil, the magnetic field generated by the current-carrying conductor when connected to the current to be measured causes a change in magnetic flux. By applying a compensation current to the feedback coil to cancel the magnetic field generated by the current to be measured, the measurement of the current to be measured is achieved by detecting the magnitude of the compensation current of the feedback coil.

[0029] In this embodiment of the invention, there are at least two sets of excitation coils and at least two sets of induction coils, with each pair of excitation coils and each pair of induction coils symmetrically distributed relative to the magnetic core.

[0030] In this embodiment of the invention, when two sets of excitation coils that are symmetrically distributed are applied with excitation currents in the same direction, the magnetic fields generated by the two sets of excitation coils are in the same direction. When the current-carrying conductor is connected to the current to be measured, it generates a magnetic field. After being converged by the magnetic core, the magnetic fields passing through the two sets of induction coils are in opposite directions. By performing differential signal processing on the induction signals of the two sets of induction coils, the detection of the current to be measured is achieved.

[0031] In this embodiment of the invention, when the induction coil is reused as a feedback coil, a compensation current is applied to two symmetrically distributed sets of feedback coils to cancel the magnetic field generated by the current to be measured, and the current to be measured is detected by detecting the magnitude of the compensation current of the feedback coil.

[0032] In this embodiment of the invention, the excitation coil serves as an induction coil, and there are two current-carrying conductors. One of the current-carrying conductors is subjected to an excitation current, and the other current-carrying conductor is connected to the magnetic field generated by the current to be measured, which passes through two symmetrically distributed sets of induction coils and has the same direction in both sets of induction coils. By superimposing the induced signals from the two sets of induction coils, the current to be measured is detected.

[0033] In this embodiment of the invention, the coil includes only two sets of induction coils, which are symmetrically wound on the magnetic core and connected in series.

[0034] When two sets of symmetrically distributed excitation coils are subjected to excitation currents in the same direction, the current-carrying conductor generates a magnetic field when connected to the current to be measured. Under the action of this magnetic field, the magnetic flux passing through the induction coil changes. By detecting the induced voltage signal of the induction coil, the current to be measured can be detected.

[0035] The present invention also provides a method for manufacturing the above-mentioned current sensing chip, comprising:

[0036] Three semiconductor wafers were selected as the bottom substrate, the middle substrate, and the top substrate, respectively.

[0037] Half-cavities with corresponding coil shapes and half-cavities with corresponding current-carrying conductor shapes are formed on the bottom substrate and the top substrate;

[0038] A cavity for accommodating the magnetic core, a coil connection structure cavity, and a current-carrying conductor connection structure cavity are formed on the intermediate layer substrate;

[0039] A magnetic core is formed by filling a cavity to house it with magnetic material.

[0040] The bottom substrate, the middle substrate, and the top substrate are combined to form a closed magnetic core cavity, a three-dimensional helical coil cavity, and a connected current-carrying conductor cavity.

[0041] A three-dimensional spiral coil is formed by filling a three-dimensional spiral coil cavity with a wound magnetic core, and a conductor material is formed by filling a connected current-carrying conductor cavity with conductor material.

[0042] In another embodiment, two semiconductor wafers are selected as the bottom substrate and the top substrate, respectively.

[0043] A cavity for accommodating the magnetic core, a half-cavity corresponding to the shape of the coil, and a half-cavity corresponding to the shape of the current-carrying conductor are formed on the bottom substrate and the top substrate.

[0044] A magnetic core is formed by filling a cavity to house it with magnetic material.

[0045] The bottom substrate and the top substrate are combined to form a closed magnetic core cavity, a three-dimensional helical coil cavity, and a connected current-carrying conductor cavity;

[0046] A three-dimensional spiral coil is formed by filling a three-dimensional spiral coil cavity with a wound magnetic core, and a conductor material is formed by filling a connected current-carrying conductor cavity with conductor material.

[0047] In this embodiment of the invention, a cavity for accommodating a magnetic core, a half-cavity corresponding to the shape of a coil, and a half-cavity corresponding to the shape of a current-carrying conductor are formed on a bottom substrate, an intermediate substrate, and a top substrate, including:

[0048] The bottom substrate is etched to form a cavity for accommodating the magnetic core, a half-cavity corresponding to the shape of the coil, and a half-cavity corresponding to the shape of the current-carrying conductor.

[0049] The intermediate layer substrate is etched to form cavities for accommodating the magnetic core, coil connection structure cavities, and corresponding current-carrying conductor connection structure cavities.

[0050] The top substrate is etched to form the other half of the cavity corresponding to the shape of the coil and the other half of the cavity corresponding to the shape of the current-carrying conductor.

[0051] In this embodiment of the invention, filling a cavity for accommodating a magnetic core with magnetic material to form a magnetic core includes: placing a prefabricated thin strip magnetic core, thick film magnetic core, or composite structure magnetic core in the cavity for accommodating the magnetic core, wherein the thin strip magnetic core, thick film magnetic core, and composite structure magnetic core are formed by processing soft magnetic materials;

[0052] Alternatively, an electroplating process can be used to deposit magnetic material inside the cavity used to house the magnetic core, thus forming the magnetic core.

[0053] In this embodiment of the invention, the manufacturing method of the current sensing chip further includes:

[0054] After the magnetic core is formed, an insulating protective layer is formed on the surface of the magnetic core to isolate the magnetic core from the coil and from the current-carrying conductor.

[0055] The current sensing chip provided by this invention integrates a magnetic core, coil, and current-carrying conductor on the same semiconductor substrate using microelectromechanical systems (MEMS) technology, and achieves current detection based on fluxgate magnetization (magnetic modulation principle). Fluxgate magnetization is extremely sensitive to weak magnetic fields. The three-dimensional coil and thick-film magnetic core integrated on the chip using MEMS technology can improve magnetic field concentration efficiency, reduce magnetic circuit losses, and effectively capture the magnetic field of weak currents. Therefore, this current sensing chip has high detection accuracy and good temperature stability, and can achieve AC and DC detection at the milliampere and microampere levels (μA~mA range). The magnetic core, coil, and current-carrying conductor of this current sensing chip are integrated on the same semiconductor substrate using MEMS technology, resulting in high integration, small size, light weight, low power consumption, and good consistency. This realizes the chip-based realization of magnetic modulation current sensors, which is beneficial for the integrated application and intelligent development of weak current sensors.

[0056] Furthermore, the current sensing chip of the present invention can employ signal enhancement methods such as differential signal processing or superposition signal processing, which can effectively suppress common-mode interference, improve anti-interference capability, and realize chip-level closed-loop current detection, with high detection accuracy, wide range, and significantly reduce sensor size and manufacturing cost.

[0057] Other features and advantages of the technical solution of the present invention will be described in detail in the following detailed embodiments section. Attached Figure Description

[0058] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0059] Figure 1 This is a schematic diagram of the current sensing chip provided in Embodiment 1 of the present invention;

[0060] Figure 2 This is a schematic diagram of another current sensing chip provided in Embodiment 1 of the present invention;

[0061] Figure 3 This is a schematic diagram of the current sensing chip provided in Embodiment 2 of the present invention;

[0062] Figure 4 This is a schematic diagram of the current sensing chip provided in Embodiment 3 of the present invention;

[0063] Figure 5 This is a schematic diagram of the structure of the current sensing chip provided in Embodiment 4 of the present invention;

[0064] Figure 6 This is a schematic diagram of the current sensing chip provided in Embodiment 5 of the present invention;

[0065] Figure 7 This is a schematic diagram of the current sensing chip provided in Embodiment Six of the present invention;

[0066] Figure 8 This is a schematic diagram illustrating the principle of the first detection method of the current sensing chip provided in this embodiment of the invention;

[0067] Figure 9 This is a schematic diagram illustrating the principle of the second detection method of the current sensing chip provided in this embodiment of the invention;

[0068] Figure 10 This is a schematic diagram illustrating the principle of the third detection method of the current sensing chip provided in this embodiment of the invention;

[0069] Figure 11 This is a schematic diagram illustrating the principle of the fourth detection method of the current sensing chip provided in this embodiment of the invention;

[0070] Figure 12 This is a schematic diagram illustrating the principle of the fifth detection method of the current sensing chip provided in this embodiment of the invention;

[0071] Figure 13 This is a schematic diagram of the current sensing chip provided in Embodiment 7 of the present invention;

[0072] Figure 14 This is a schematic diagram of another current sensing chip provided in Embodiment 7 of the present invention;

[0073] Figure 15 This is a schematic diagram illustrating the detection method of the current sensing chip provided in Embodiment 7 of the present invention;

[0074] Figure 16 This is a flowchart of a method for manufacturing a current sensing chip provided in an embodiment of the present invention.

[0075] Explanation of reference numerals in the attached figures

[0076] 1-Substrate, 2-Magnetic core, 2-1-First type of magnetic permeability core, 2-2-Second type of magnetic permeability core,

[0077] 3-Excitation coil, 3-1-First group of excitation coils, 3-2-Second group of excitation coils;

[0078] 4-Induction coil, 4-1-First group of induction coils, 4-2-Second group of induction coils

[0079] 5 - Current-carrying conductor, 5-1 - First current-carrying conductor, 5-2 - Second current-carrying conductor.

[0080] 7-Feedback coil. Detailed Implementation

[0081] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0082] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0083] Existing Hall effect current sensors and magnetoresistive current sensors still need further improvement in terms of sensitivity, measurement accuracy, and temperature stability, and cannot meet the requirements for precise measurement of small currents in the microampere to milliampere range. Magnetic modulation current sensors, on the other hand, offer high accuracy and good temperature stability, giving them unique advantages in detecting weak currents in the milliampere or microampere range. Traditional magnetic modulation current sensors are made using enameled wire wound magnetic cores, which suffers from uneven coil winding, poor consistency, large size, and high power consumption, hindering the integration and intelligent development of small current sensors.

[0084] This invention provides a current sensing chip based on the principle of magnetic modulation, comprising a magnetic core, a coil, and a current-carrying conductor. The magnetic core, coil, and current-carrying conductor are formed on the same semiconductor substrate using microelectromechanical systems (MEMS) technology. The magnetic core includes at least one independent magnetic core or a composite structure magnetic core composed of soft magnetic material. At least one current-carrying conductor is disposed in a region close to the magnetic core or wound around the magnetic core. The coil includes at least one set of induction coils, or includes at least one set of induction coils and at least one set of excitation coils. Both the excitation coil and the induction coil are wound around the magnetic core, and both can be reused as feedback coils. When a current to be measured is connected to the current-carrying conductor, the magnetic field generated by the current to be measured around the current-carrying conductor acts on the magnetic core, causing a change in magnetic flux. The measurement of the current to be measured is achieved by detecting the output signal of the induction coil or the feedback coil.

[0085] The method for forming the magnetic core, coil, and current-carrying conductor on the same semiconductor substrate using microelectromechanical systems (MEMS) technology is as follows: forming a half-coil cavity and a half-current-carrying conductor cavity on a bottom substrate; forming a half-coil cavity and a half-current-carrying conductor cavity on a top substrate; forming a magnetic core cavity, a coil connection structure cavity, and a current-carrying conductor connection structure cavity on a bottom substrate or a top substrate; or forming a magnetic core cavity, a coil connection structure cavity, and a current-carrying conductor connection structure cavity on an intermediate substrate; filling the magnetic core cavity with magnetic material to form a magnetic core; combining the bottom substrate and the top substrate, or combining the bottom substrate, the intermediate substrate, and the top substrate to form a closed magnetic core cavity, a three-dimensional helical coil cavity, and a connected current-carrying conductor cavity; filling the three-dimensional helical coil cavity with coil material to form a three-dimensional helical coil wound with the magnetic core; and filling the connected current-carrying conductor cavity with conductor material to form a current-carrying conductor.

[0086] The current sensing chip of this invention is based on the principle of magnetic modulation, offering high accuracy and good temperature stability. It can achieve AC and DC detection at the milliampere and microampere levels (μA~mA range). The magnetic core, coil, and current-carrying conductor of this current sensing chip are integrated on the same semiconductor substrate using microelectromechanical systems (MEMS) technology, resulting in high integration, small size, light weight, low power consumption, and good consistency. This realizes the chip-based realization of magnetic modulation current sensors, which is beneficial for the integrated application and intelligent development of weak current sensors. Furthermore, the current sensing chip of this invention can employ signal enhancement methods such as differential signal processing or superposition signal processing to effectively suppress common-mode interference, improve anti-interference capabilities, and achieve chip-level closed-loop current detection with high accuracy and wide range, while significantly reducing sensor size and manufacturing costs.

[0087] Example 1

[0088] Figure 1 and Figure 2This is a schematic diagram of the current sensing chip provided in Embodiment 1 of the present invention. Figure 1 and Figure 2 As shown, the current sensing chip provided in this embodiment includes a magnetic core, a coil, and a current-carrying conductor. The magnetic core 2, the coil, and the current-carrying conductor 5 are formed on the same semiconductor substrate 1 based on MEMS technology. Figure 1 The medium-current-carrying conductor 5 is disposed through the cavity of the magnetic core 2. Figure 2 A medium-current conductor 5 is wound around a magnetic core 2. The coil includes a set of excitation coils 3 and a set of induction coils 4, both of which are wound around the magnetic core 2.

[0089] The magnetic core of the current sensing chip can be ring-shaped, racetrack-shaped, rectangular, or rod-shaped. In this embodiment, the magnetic core 2 is racetrack-shaped.

[0090] The current sensing chip can have one, two, or more current-carrying conductors. Figure 1 In the middle, there is one current-carrying conductor 5. The current-carrying conductor is set through the cavity of the racetrack-shaped magnetic core to enhance the magnetic concentration effect of the magnetic core on the current-carrying conductor.

[0091] In this embodiment, both the excitation coil and the induction coil are three-dimensional structures, wound helically around a magnetic core. Both the excitation coil and the induction coil can reuse a feedback coil. If the induction coil is used as a feedback coil, chip-level closed-loop current detection can be achieved through the feedback coil.

[0092] In this embodiment, the magnetic core is a thin strip core or a thick film core made of soft magnetic material, and it is a high-permeability magnetic core. The soft magnetic material is permalloy, amorphous alloy, or nanocrystalline alloy, etc.

[0093] The current sensing chip in this embodiment is based on the magnetic modulation principle (fluxgate principle), utilizing the magnetic field modulation effect of a high-permeability magnetic core in a periodic saturation state to indirectly measure the current to be measured. The current sensing chip of this invention can be adapted to practical application requirements, employing two methods to achieve AC and DC detection in the μA~mA range, thus improving the flexibility of detection.

[0094] The first detection method is as follows: Figure 8 As shown, an excitation current is applied to the excitation coil. i ex When the current-carrying conductor is connected to the current to be measured I p A magnetic field H0 is generated, which causes a change in the magnetic flux passing through the induction coil. The current to be measured is detected by detecting the induced voltage signal of the induction coil.

[0095] The second detection method is as follows: Figure 9As shown, when the induction coil is used as a feedback coil, an excitation current is applied to the excitation coil. i ex When the current-carrying conductor is connected to the current to be measured I p A magnetic field H0 is generated, which causes a change in the magnetic flux passing through the induction coil, applying a compensation current to the feedback coil. i co To counteract the change in magnetic flux caused by the magnetic field H0, the compensation current of the feedback coil is detected. i co The size is used to detect the current to be measured.

[0096] The current sensing chip provided in this embodiment uses fluxgate magnetization (FGM) technology to detect current. FGM technology is extremely sensitive to weak magnetic fields. The three-dimensional coil and thick-film magnetic core integrated on the chip using MEMS technology can improve magnetic field concentration efficiency, reduce magnetic circuit losses, and effectively capture even weak current magnetic fields. Figure 1 A model simulation of the current sensing chip structure shown is performed, and the simulation results demonstrate that this structure can achieve mA-level current detection. Based on the following... Figure 2 The current sensing chip structure shown was simulated, and the simulation results show that the structure can achieve μA-level current detection.

[0097] Example 2

[0098] Figure 3 This is a schematic diagram of the current sensing chip provided in Embodiment 2 of the present invention. Figure 3 As shown, the current sensing chip provided in this embodiment includes a magnetic core, a coil, and a current-carrying conductor. The magnetic core 2, the coil, and the current-carrying conductor 5 are formed on the same semiconductor substrate 1 using MEMS technology. The coil includes a set of excitation coils 3, a set of induction coils 4, and a set of feedback coils 7. The excitation coils 3, induction coils 4, and feedback coils 7 are all three-dimensional structures, and the three-dimensional excitation coils, induction coils, and feedback coils are wound in a spiral manner on the magnetic core. The magnetic core 2 is racetrack-shaped. The racetrack-shaped magnetic core has a symmetrical first magnetic axis and a symmetrical third magnetic axis and a fourth magnetic axis. A set of excitation coils and a set of induction coils are wound on the first magnetic axis, and a set of feedback coils is wound on the second magnetic axis.

[0099] Unlike Embodiment 1, Embodiment 2 includes a set of feedback coils 7. The current sensing chip in Embodiment 2 can measure the current to be measured using the second detection method described above. Specifically, an excitation current is applied to the excitation coil. i ex When the current-carrying conductor is connected to the current to be measured I p A magnetic field H0 is generated, which causes a change in the magnetic flux passing through the induction coil, applying a compensation current to the feedback coil. ico To counteract the change in magnetic flux caused by the magnetic field H0, the compensation current of the feedback coil is detected. i co The size is used to detect the current to be measured.

[0100] Example 3

[0101] Figure 4 This is a schematic diagram of the current sensing chip provided in Embodiment 3 of the present invention. Figure 4 As shown, the current sensing chip provided in this embodiment includes a magnetic core, a coil, and a current-carrying conductor. The magnetic core, coil, and current-carrying conductor 5 are formed on the same semiconductor substrate 1 using MEMS technology. The coil includes a set of excitation coils 3, a set of induction coils 4, and a set of feedback coils 7. The excitation coil, induction coil, and feedback coil are all three-dimensional structures, and the three-dimensional excitation coil, induction coil, and feedback coil are wound around the magnetic core in a helical manner.

[0102] Unlike Embodiment 2, the magnetic core in Embodiment 3 is a composite magnetic core, which is a composite structure composed of two soft magnetic materials with different permeabilities. The magnetic core includes a core made of a soft magnetic material with a first permeability and a core made of a soft magnetic material with a second permeability. The feedback coil 7 is wound on the magnetic core 2-1 with the first permeability, while the excitation coil 3 and the induction coil 4 are wound on the magnetic core 2-2 with the second permeability.

[0103] The current sensing chip in Example 3 can measure the current to be measured using the second detection method described above. Specifically, an excitation current is applied to the excitation coil. i ex When the current-carrying conductor is connected to the current to be measured I p A magnetic field H0 is generated, which causes a change in the magnetic flux passing through the induction coil, applying a compensation current to the feedback coil. i co To counteract the change in magnetic flux caused by the magnetic field H0, the compensation current of the feedback coil is detected. i co The size is used to detect the current to be measured.

[0104] Example 4

[0105] Figure 5 This is a schematic diagram of the current sensing chip provided in Embodiment 4 of the present invention. Figure 5As shown, the current sensing chip provided in this embodiment includes a magnetic core, a coil, and a current-carrying conductor. The magnetic core 2, the coil, and the current-carrying conductor 5 are formed on the same semiconductor substrate 1 using MEMS technology. The coil includes two sets of excitation coils: a first set of excitation coils 3-1 and a second set of excitation coils 3-2, and two sets of induction coils: a first set of induction coils 4-1 and a second set of induction coils 4-2. Both sets of excitation coils and both sets of induction coils are wound on the magnetic core.

[0106] Unlike Embodiment 1, Embodiment 4 has two sets of excitation coils and induction coils. The first set of excitation coils 3-1 and the second set of excitation coils 3-2 are symmetrically distributed relative to the magnetic core 2, as are the first set of induction coils 4-1 and the second set of induction coils 4-2. Both the excitation coils and induction coils are three-dimensional structures, wound helically around the magnetic core. The magnetic core 2 is racetrack-shaped. The racetrack-shaped magnetic core has symmetrical first and second magnetic axes, and symmetrical third and fourth magnetic axes. The first set of excitation coils 3-1 and the first set of induction coils 4-1 are wound around the first magnetic axis, and the second set of excitation coils 3-2 and the second set of induction coils 4-2 are wound around the second magnetic axis. A current-carrying conductor 5 is disposed through the cavity of the racetrack-shaped magnetic core.

[0107] The current sensing chip in this embodiment is based on the magnetic modulation principle (fluxgate principle), utilizing the magnetic field modulation effect of a high-permeability magnetic core in a periodic saturation state to indirectly measure the current to be measured. The current sensing chip of this invention can be adapted to practical application requirements, employing a third or fourth detection method to achieve AC and DC detection in the μA~mA range, thus improving the flexibility of detection.

[0108] The third detection method is as follows: Figure 10 As shown, two sets of symmetrically distributed excitation coils are subjected to excitation currents in the same direction. i ex The magnetic field H generated by the two sets of excitation coils ex The directions are the same. The current-carrying conductor is connected to the current being measured, I. p A magnetic field H0 is generated, which converges at the magnetic core and passes through the upper and lower sets of induction coils, resulting in opposite magnetic field directions. By performing differential signal processing on the induced signals from the two sets of induction coils, the chip outputs a signal V. out =V out1 -V out2 It can eliminate the induced electromotive force generated by the transformer effect in the excitation coil, enhance the change in induced electromotive force in the induction coil caused by the magnetic field generated by the current to be measured, and effectively suppress common-mode interference, thereby improving anti-interference capability and achieving accurate detection of the current to be measured.

[0109] The fourth detection method is as follows: Figure 11As shown, two sets of induction coils are used as feedback coils, applying reverse excitation currents to two symmetrically distributed excitation coils. i ex The magnetic field H generated by the two sets of excitation coils ex The directions are opposite. The current-carrying conductor is connected to the current being measured, I. p A magnetic field H0 is generated. A compensation current is applied to the feedback coil. i co The change in magnetic flux caused by the magnetic field H0 is offset, and the current to be measured is detected by detecting the magnitude of the compensation current of the feedback coil.

[0110] Example 5

[0111] Figure 6 This is a schematic diagram of the current sensing chip provided in Embodiment 5 of the present invention. Figure 6 As shown, the current sensing chip provided in this embodiment includes a magnetic core, coils, and current-carrying conductors. The magnetic core 2, coils, and current-carrying conductors are formed on the same semiconductor substrate 1 using MEMS technology. The coils include two sets of excitation coils 3-1 and 3-2 and two sets of induction coils 4-1 and 4-2. Both sets of excitation coils and induction coils are wound on the magnetic core. The first set of excitation coils 3-1 and the second set of excitation coils 3-2 are symmetrically distributed with respect to the magnetic core 2, and the first set of induction coils 4-1 and the second set of induction coils 4-2 are also symmetrically distributed with respect to the magnetic core 2. There are two current-carrying conductors, including a first current-carrying conductor 5-1 and a second current-carrying conductor 5-2. Both the excitation coils and induction coils are three-dimensional structures, wound in a spiral manner on the magnetic core. The magnetic core 2 is racetrack-shaped. The racetrack-shaped magnetic core has symmetrical first and second magnetic axes, and symmetrical third and fourth magnetic axes. One set of excitation coils and one set of induction coils are wound on the first magnetic axis, and the other set of excitation coils and the other set of induction coils are wound on the second magnetic axis.

[0112] Unlike Embodiment 4, Embodiment 5 uses two current-carrying conductors. The first current-carrying conductor 5-1 is disposed through the cavity of the racetrack-shaped magnetic core, and the second current-carrying conductor 5-2 is disposed in the region near the magnetic core and parallel to the magnetic core. The two current-carrying conductors can enhance the magnetic field concentration effect of the magnetic core on the current-carrying conductors.

[0113] The current sensing chip in this embodiment is based on the magnetic modulation principle (fluxgate principle), utilizing the magnetic field modulation effect of a high-permeability magnetic core in a periodic saturation state to indirectly measure the current to be measured. This current sensing chip can be adapted to practical application requirements by employing a fifth detection method (both current-carrying conductors are connected to the current to be measured) to achieve AC and DC detection over a wide range of mA to A.

[0114] The fifth detection method is as follows Figure 12As shown, an excitation current is applied through the first current-carrying conductor 5-1. i ex At this point, all the coils wound on the magnetic core are used as induction coils (the excitation coil also serves as an induction coil). The magnetic field H generated by the first current-carrying conductor 5-1 under the excitation current... ex The conductor passes through both sets of induction coils, and the directions are opposite in the two sets of induction coils. The second current-carrying conductor 5-2 is connected to the current to be measured, Ip. p The generated magnetic field H0 passes through both sets of induction coils, and its direction is the same in both sets of coils. The induced signals from the two sets of induction coils are superimposed, resulting in the chip output signal V. out =V out1 +V out2 It can eliminate the induced electromotive force generated by the transformer effect in the excitation coil, and at the same time enhance the change in induced electromotive force in the induction coil caused by the magnetic field generated by the current to be measured, thereby realizing the accurate detection of the current to be measured.

[0115] Example 6

[0116] Figure 7 This is a schematic diagram of the current sensing chip provided in Embodiment Six of the present invention. Figure 7 As shown, the current sensing chip provided in this embodiment includes a magnetic core, coils, and current-carrying conductors. The magnetic core 2, coils, and current-carrying conductors are formed on the same semiconductor substrate 1 using MEMS technology. The coils include two sets of excitation coils 3-1 and 3-2 and two sets of induction coils 4-1 and 4-2. Both sets of excitation coils and induction coils are wound on the magnetic core. The first set of excitation coils 3-1 and the second set of excitation coils 3-2 are symmetrically distributed with respect to the magnetic core 2, and the first set of induction coils 4-1 and the second set of induction coils 4-2 are also symmetrically distributed with respect to the magnetic core 2. There are two current-carrying conductors, including a first current-carrying conductor 5-1 and a second current-carrying conductor 5-2. Both the excitation coils and induction coils are three-dimensional structures, wound in a spiral manner on the magnetic core. The magnetic core 2 is racetrack-shaped. The racetrack-shaped magnetic core has symmetrical first and second magnetic axes, and symmetrical third and fourth magnetic axes. One set of excitation coils and one set of induction coils are wound on the first magnetic axis, and the other set of excitation coils and the other set of induction coils are wound on the second magnetic axis. Figure 7 In this configuration, two current-carrying conductors are arranged through the cavity of the racetrack-shaped magnetic core. Alternatively, there is another arrangement: the two current-carrying conductors are wound around the third and fourth magnetic axes of the core, respectively (not shown in the attached diagram).

[0117] Unlike Embodiment 5, in Embodiment 6, the two current-carrying conductors are disposed through the cavity of the racetrack-shaped magnetic core. The first current-carrying conductor 5-1 and the second current-carrying conductor 5-2 are respectively close to the third and fourth magnetic axes of the magnetic core, or the first current-carrying conductor 5-1 and the second current-carrying conductor 5-2 are respectively wound around the third and fourth magnetic axes of the magnetic core to enhance the magnetic focusing effect.

[0118] The current sensing chip in this embodiment can use the first, second, third, and fourth detection methods described above. Both current-carrying conductors are connected to the current to be measured, which is used to measure the residual current of the two wires, thereby realizing complex residual current detection in the range of μA to mA.

[0119] Example 7

[0120] Figure 13 and Figure 14 This is a schematic diagram of the current sensing chip provided in Embodiment 7 of the present invention. Figure 13 and Figure 14 As shown, the current sensing chip provided in this embodiment includes two sets of induction coils 4, without an excitation coil. The two sets of induction coils 4 are symmetrically wound on the magnetic core 2. A current-carrying conductor 5 is disposed through the cavity of the magnetic core 2. The two sets of induction coils 4 are connected in series by a wire, and the two sets of induction coils serve as both input and output. Figure 13 The middle magnetic core 2 is ring-shaped. Figure 14 The shape of the middle magnetic core 2 is rectangular.

[0121] like Figure 15 As shown, when using this current sensing chip for current detection, a unidirectional excitation current i is applied to two symmetrically distributed sets of excitation coils. ex When a current-carrying conductor is connected to the current to be measured, it generates a magnetic field H0. Under the action of the magnetic field H0, the magnetic flux passing through the induction coil changes. The induced voltage signal V of the induction coil is detected by this magnetic field. out This enables the detection of the current Ip to be measured.

[0122] The current sensing chip provided in the above embodiments consists of a wafer substrate, a miniature magnetic core, a helical coil, and a current-carrying conductor. The three-dimensional helical coil is wound around the miniature magnetic core, with a coil height reaching several hundred micrometers, allowing for a larger cross-sectional area magnetic core structure and improving current detection sensitivity. The current-carrying conductor passes through the magnetic core or is arranged parallel to it, significantly enhancing the magnetic focusing effect and lowering the current detection lower limit. The miniature magnetic core, helical coil, and current-carrying conductor are integrated and fabricated on the same wafer substrate using microelectromechanical systems (MEMS) technology, achieving chip-level fabrication of small current sensors with high production efficiency and good consistency.

[0123] The current sensing chip provided in the above embodiments uses fluxgate magnetization (FGM) technology to detect current. FGM technology is extremely sensitive to weak magnetic fields. The three-dimensional coil and thick-film magnetic core integrated on the chip using MEMS technology can improve magnetic field concentration efficiency, reduce magnetic circuit losses, and effectively capture even weak current magnetic fields. Therefore, this chip can meet the requirements for wide-range, high-precision, and high-bandwidth AC / DC current detection from microamps to amperes.

[0124] The current sensing chip provided in this invention integrates the magnetic core, coil, and current-carrying conductor on the same wafer substrate using microelectromechanical systems (MEMS) technology, achieving a magnetic core thickness of 200-300 μm. A three-dimensional helical coil is wound around the micro-magnetic core, with a coil height reaching several hundred micrometers, accommodating a larger cross-sectional area magnetic core structure and significantly improving current detection sensitivity.

[0125] The present invention also provides a method for manufacturing the above-described current sensing chip. For example... Figure 16 As shown, the manufacturing method of the current sensing chip includes the following steps:

[0126] S121 uses three semiconductor wafers as the bottom substrate, the middle substrate, and the top substrate, respectively.

[0127] S122, forming a half-cavity with a coil shape and a half-cavity with a current-carrying conductor shape on the bottom substrate and the top substrate;

[0128] S123, a cavity for accommodating the magnetic core, a coil connection structure cavity, and a current-carrying conductor connection structure cavity are formed on the intermediate layer substrate;

[0129] S124, A magnetic core is formed by filling a cavity for housing the magnetic core with magnetic material;

[0130] S125 combines the bottom substrate, the middle substrate, and the top substrate to form a closed magnetic core cavity, a three-dimensional spiral coil cavity, and a connected current-carrying conductor cavity.

[0131] S126, a three-dimensional spiral coil is formed by filling a three-dimensional spiral coil cavity with coil material to form a wound magnetic core, and a current-carrying conductor is formed by filling a connected current-carrying conductor cavity with conductor material.

[0132] In step S121 above, the selected wafer is made of materials such as silicon, silicon dioxide, or silicon-on-insulator (SOI).

[0133] In steps S122 and S123 above, the bottom substrate is etched to form a half-cavity corresponding to the coil shape and a half-cavity corresponding to the current-carrying conductor shape, respectively; the middle layer substrate is etched to form a cavity for accommodating the magnetic core, a coil connection structure cavity, and a current-carrying conductor connection structure cavity, respectively; and the top layer substrate is etched to form another half-cavity corresponding to the coil shape and another half-cavity corresponding to the current-carrying conductor shape.

[0134] In step S124 above, a pre-fabricated thin-strip magnetic core, thick-film magnetic core, or composite structure magnetic core is placed in a cavity on the intermediate substrate to accommodate the magnetic core, or a magnetic material is deposited in the cavity to accommodate the magnetic core using an electroplating process to form the magnetic core. The materials for the thin-strip and thick-film magnetic cores can be soft magnetic materials. For example, thin-strip magnetic cores can be fabricated by laser cutting of strips, or thick-film magnetic cores can be fabricated by precision machining after strip bonding and curing.

[0135] In step S126 above, coil material is filled into the three-dimensional helical coil cavity to form a three-dimensional helical coil with a wound magnetic core, and conductor material is filled into the connected current-carrying conductor cavity to form a current-carrying conductor. The coil material and conductor material can be a single metal material or an alloy material.

[0136] The manufacturing method of the current sensing chip described above further includes: after forming the magnetic core, i.e. after step S124, forming an insulating protective layer on the surface of the magnetic core to isolate the magnetic core from the coil and the magnetic core from the current-carrying conductor.

[0137] In another embodiment, the method for manufacturing the above-mentioned current sensing chip includes the following steps:

[0138] Two semiconductor wafers were selected as the bottom substrate and the top substrate, respectively.

[0139] A cavity for accommodating the magnetic core, a half-cavity corresponding to the shape of the coil, and a half-cavity corresponding to the shape of the current-carrying conductor are formed on the bottom substrate and the top substrate; or, a cavity for accommodating the magnetic core is etched on the top substrate.

[0140] A magnetic core is formed by filling a cavity to house it with magnetic material.

[0141] The bottom substrate and the top substrate are combined to form a closed magnetic core cavity, a three-dimensional helical coil cavity, and a connected current-carrying conductor cavity;

[0142] A three-dimensional spiral coil is formed by filling a three-dimensional spiral coil cavity with a wound magnetic core, and a conductor material is formed by filling a connected current-carrying conductor cavity with conductor material.

[0143] Specifically, a prefabricated thin-strip magnetic core, thick-film magnetic core, or composite structure magnetic core is placed within a cavity used to house the magnetic core. The thin-strip magnetic core, thick-film magnetic core, and composite structure magnetic core are formed using soft magnetic materials. Alternatively, a magnetic material is deposited within the cavity to house the magnetic core using an electroplating process to form the magnetic core.

[0144] After the magnetic core is formed, an insulating protective layer is formed on the surface of the magnetic core to isolate the magnetic core from the coil and from the current-carrying conductor.

[0145] The current sensing chip fabrication method provided in this invention does not rely on electroplating processes, has better compatibility with large-scale integrated circuit processes, and realizes chip-level fabrication and wafer-level manufacturing of small current sensors. Specifically, the current sensing chip and fabrication method of this invention have the following advantages:

[0146] (1) This chip does not require the traditional magnetic ring structure. The magnetic core, coil and current-carrying wire are integrated on the same wafer substrate through MEMS process. The integration is high and can effectively solve the problems of large size, heavy weight, high cost and poor consistency of existing small current sensors.

[0147] (2) The chip adopts the principle of electromagnetic induction or magnetic modulation, and has high measurement accuracy, which can meet the requirements of AC and DC small current measurement in the range of microamps to amperes;

[0148] (3) The chip can use differential signal processing, which can effectively suppress common-mode interference and improve anti-interference capability;

[0149] (4) The chip can provide chip-level closed-loop current detection, which can achieve high-precision, high-bandwidth and wide-range current detection, significantly reducing sensor size and cost.

[0150] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. Furthermore, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. As long as such combination does not violate the spirit of the embodiments of the present invention, it should also be considered as the content disclosed in the embodiments of the present invention.

Claims

1. A current sensing chip, comprising a magnetic core, a coil, and a current-carrying conductor, characterized in that, The magnetic core is an independent magnetic core or a composite structure magnetic core made of soft magnetic material, and the current-carrying conductor is disposed in a region close to the magnetic core or wound around the magnetic core; The coil includes at least one set of induction coils and at least one set of excitation coils. Both the induction coils and the excitation coils are wound on a magnetic core, and both the excitation coils and the induction coils can be reused as feedback coils. The magnetic core is racetrack shaped, and at least one current-carrying conductor is disposed through the cavity of the racetrack-shaped magnetic core; When an excitation current is applied to the excitation coil, the magnetic field generated when the current-carrying conductor is connected to the current to be measured causes a change in the magnetic flux passing through the induction coil. The current to be measured is detected by detecting the induced voltage signal of the induction coil. When the induction coil is reused as a feedback coil, a compensation current is applied to the feedback coil to cancel the change in magnetic flux caused by the magnetic field generated when the current-carrying conductor is connected to the current to be measured. The current to be measured is detected by detecting the magnitude of the compensation current of the feedback coil. The magnetic core, coil, and current-carrying conductor are formed on the same semiconductor substrate, and the formation method includes: A half-coil cavity and a half-current-carrying conductor cavity are formed on the bottom substrate; A half-coil cavity and a half-current-carrying conductor cavity are formed on the top substrate; A magnetic core cavity, a coil connection structure cavity, and a current-carrying conductor connection structure cavity are formed on a bottom substrate or a top substrate; or, a magnetic core cavity, a coil connection structure cavity, and a current-carrying conductor connection structure cavity are formed on an intermediate substrate. A magnetic core is formed by filling the cavity with magnetic material. By combining the bottom substrate and the top substrate, or by combining the bottom substrate, the intermediate substrate and the top substrate, a closed magnetic core cavity, a three-dimensional helical coil cavity and a connected current-carrying conductor cavity can be formed. A three-dimensional spiral coil is formed by filling a three-dimensional spiral coil cavity with a wound magnetic core, and a conductor material is formed by filling a connected current-carrying conductor cavity with conductor material.

2. The current sensing chip according to claim 1, characterized in that, The racetrack-shaped magnetic core has a symmetrical first and second magnetic axis, and a symmetrical third and fourth magnetic axis; At least one set of excitation coils is wound on the first magnetic shaft, and at least one set of induction coils or at least one set of feedback coils is wound on the second magnetic shaft.

3. The current sensing chip according to claim 2, characterized in that, There are two current-carrying conductors. One current-carrying conductor runs through the cavity of the racetrack-shaped magnetic core, and the other current-carrying conductor is located in the region close to the magnetic core and parallel to the magnetic core.

4. The current sensing chip according to claim 1, characterized in that, Both the excitation coil and the induction coil are three-dimensional structures, and the three-dimensional excitation coil and the induction coil are wound on the magnetic core in a spiral manner.

5. The current sensing chip according to claim 1, characterized in that, The magnetic core is a thin strip magnetic core or a thick film magnetic core made of soft magnetic material, such as permalloy, amorphous alloy or nanocrystalline alloy.

6. The current sensing chip according to claim 1, characterized in that, The magnetic core is a composite structure magnetic core made of two soft magnetic materials with different permeabilities; The feedback coil is wound around a core made of a soft magnetic material with the first permeability; The excitation coil and the induction coil are wound on a magnetic core made of a soft magnetic material with a second permeability.

7. The current sensing chip according to claim 1, characterized in that, There are at least two sets of excitation coils and at least two sets of induction coils, with each pair of excitation coils and each pair of induction coils symmetrically distributed relative to the magnetic core.

8. The current sensing chip according to claim 7, characterized in that, The current-carrying conductor generates a magnetic field when connected to the current to be measured. When two sets of excitation coils are symmetrically distributed and excitation currents in the same direction are applied, the magnetic fields generated by the two sets of excitation coils are in the same direction. After being converged by the magnetic core, the magnetic fields passing through the two sets of induction coils are in opposite directions. By performing differential signal processing on the induction signals of the two sets of induction coils, the current to be measured can be detected.

9. The current sensing chip according to claim 8, characterized in that, When the induction coil is reused as a feedback coil, a compensation current is applied to two symmetrically distributed sets of feedback coils to cancel the magnetic field generated by the current to be measured. The current to be measured is detected by detecting the magnitude of the compensation current of the feedback coil.

10. The current sensing chip according to claim 7, characterized in that, There are two current-carrying conductors. One of the current-carrying conductors is subjected to an excitation current, and the excitation coil serves as an induction coil. The other current-carrying conductor is connected to the magnetic field generated by the current to be measured, which passes through two symmetrically distributed sets of induction coils and has the same direction in both sets of induction coils. By superimposing the induced signals from the two sets of induction coils, the current to be measured can be detected.

11. A method for manufacturing a current sensing chip, characterized in that, include: Three semiconductor wafers were selected as the bottom substrate, the middle substrate, and the top substrate, respectively. Half-cavities with corresponding coil shapes and half-cavities with corresponding current-carrying conductor shapes are formed on the bottom substrate and the top substrate; A cavity for accommodating the magnetic core, a coil connection structure cavity, and a current-carrying conductor connection structure cavity are formed on the intermediate layer substrate; A magnetic core is formed by filling a cavity to house it with magnetic material. The bottom substrate, the middle substrate, and the top substrate are combined to form a closed magnetic core cavity, a three-dimensional helical coil cavity, and a connected current-carrying conductor cavity. A three-dimensional spiral coil is formed by filling a coil cavity with coil material to form a three-dimensional spiral coil with a wound magnetic core, and a current-carrying conductor is formed by filling a connected current-carrying conductor cavity with conductor material. Alternatively, the method may include: Two semiconductor wafers were selected as the bottom substrate and the top substrate, respectively. A cavity for accommodating the magnetic core, a half-cavity corresponding to the shape of the coil, and a half-cavity corresponding to the shape of the current-carrying conductor are formed on the bottom substrate and the top substrate. A magnetic core is formed by filling a cavity to house it with magnetic material. The bottom substrate and the top substrate are combined to form a closed magnetic core cavity, a three-dimensional helical coil cavity, and a connected current-carrying conductor cavity; A three-dimensional spiral coil is formed by filling a coil cavity with coil material to form a three-dimensional spiral coil with a wound magnetic core, and a current-carrying conductor is formed by filling a connected current-carrying conductor cavity with conductor material. The magnetic core is racetrack shaped, and at least one current-carrying conductor is disposed through the cavity of the racetrack-shaped magnetic core; When an excitation current is applied to the excitation coil, the magnetic field generated when the current-carrying conductor is connected to the current to be measured causes a change in the magnetic flux passing through the induction coil. The current to be measured is detected by detecting the induced voltage signal of the induction coil. When the induction coil is reused as a feedback coil, a compensation current is applied to the feedback coil to cancel the change in magnetic flux caused by the magnetic field generated when the current-carrying conductor is connected to the current to be measured. The current to be measured is detected by detecting the magnitude of the compensation current of the feedback coil.

12. The method for manufacturing a current sensing chip according to claim 11, characterized in that, A magnetic core is formed by filling a cavity containing magnetic material, including: A prefabricated thin strip magnetic core, thick film magnetic core, or composite structure magnetic core is placed in a cavity for accommodating the magnetic core. The thin strip magnetic core, thick film magnetic core, and composite structure magnetic core are formed by processing soft magnetic materials. Alternatively, an electroplating process can be used to deposit magnetic material inside the cavity used to house the magnetic core, thus forming the magnetic core.

13. The method for manufacturing a current sensing chip according to claim 11, characterized in that, The method further includes: After the magnetic core is formed, an insulating protective layer is formed on the surface of the magnetic core to isolate the magnetic core from the coil and from the current-carrying conductor.

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