Current sensing chip and manufacturing method

Abstract

The invention provides a current sensing chip and a manufacturing method, and relates to the technical field of sensing chips. A magnetic core, a coil and a current-carrying conductor of the current sensing chip are formed on the same semiconductor substrate based on a micro electro mechanical system technology, the magnetic core is an independent magnetic core or a composite structure magnetic core made of a soft magnetic material, and the current-carrying conductor is arranged in an area close to the magnetic core; the coils comprise at least one group of excitation coils and at least one group of induction coils, the excitation coils and the induction coils are wound on the magnetic core, and the excitation coils and the induction coils can be reused as feedback coils; when the current-carrying conductor is connected with a to-be-measured current, a magnetic field generated by the to-be-measured current around the current-carrying conductor acts on the magnetic core to cause magnetic flux change, and the to-be-measured current is measured by detecting an output signal of the induction coil or the feedback coil. According to the invention, the anti-interference capability can be improved, chip-level closed-loop current detection can be realized, the detection precision is high, the range is wide, and the size and the manufacturing cost of the sensor are obviously reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor chips, and in particular to a current sensor chip and a manufacturing method thereof. Background Art

[0002] In power systems, current detection is an important means of monitoring the status of power equipment. Low-current sensors are primarily used to measure weak currents such as leakage current. Examples include monitoring leakage current in insulated lines in distribution networks and monitoring the insulation status of substation equipment. Installing low-current sensors on key facilities and equipment, such as transmission lines, cables, transformers, and circuit breakers, can promptly detect abnormal current fluctuations and provide early warning of potential faults, thereby ensuring the safe and stable operation of the power grid. Furthermore, as the proportion of distributed energy resources connected to the power grid increases, demand for AC and DC low-current sensors is growing in new energy equipment such as photovoltaic inverters and charging stations. Current sensors are also developing towards higher precision, miniaturization, and intelligence.

[0003] Current sensor types include resistor shunts, Rogowski coils, current transformers, Hall effect current sensors, magnetoresistive current sensors, magnetic modulation 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 poor temperature stability and vibration immunity. Hall effect current sensors, magnetoresistive current sensors, and magnetic modulation current sensors are currently the three most widely used types of current sensors.

[0004] Existing Hall-effect current sensors and magnetoresistive current sensors need further improvement in sensitivity, measurement accuracy, and temperature stability, and are unable to meet the demand for precise measurement of small currents in the microampere to milliampere range. Magnetic modulation current sensors offer high precision and excellent temperature stability, offering unique advantages in detecting weak currents in the milliampere or microampere range. Traditional magnetic modulation current sensors are manufactured using enameled wire wrapped around a magnetic core, which results in uneven coil winding and poor consistency. They are also bulky and consume high power, hindering the integrated and intelligent development of small current sensors. Summary of the Invention

[0005] In order to solve the above technical defects, the present invention provides a current sensor chip and a 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, which is arranged in an area near 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 of which are wound around the magnetic core, and both of which can be reused as feedback coils. When the current-carrying conductor is connected to the current to be measured, 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.

[0007] The magnetic core, the coil, and the current-carrying conductor are formed on the same semiconductor substrate. The forming method includes: Forming a half-coil cavity and a half-current-carrying conductor cavity on the bottom substrate; Forming a half-coil cavity and a half-current-carrying conductor cavity on the top substrate; Forming a magnetic core cavity, a coil connection structure cavity, and a current-carrying conductor connection structure cavity on the bottom substrate or the top substrate; or forming a magnetic core cavity, a coil connection structure cavity, and a current-carrying conductor connection structure cavity on the 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 spiral-shaped coil cavity, and a connected current-carrying conductor cavity; Filling the three-dimensional spiral-shaped coil cavity with coil material to form a three-dimensional spiral coil wound around the magnetic core, and filling the connected current-carrying conductor cavity with conductor material to form a current-carrying conductor.

[0008] In the embodiment of the present invention, the shape of the magnetic core is annular, racetrack-shaped, rectangular, or rod-shaped.

[0009] In the embodiment of the present invention, the racetrack-shaped magnetic core has a symmetric first magnetic axis and a second magnetic axis, and a symmetric third magnetic axis and a fourth magnetic axis; At least one set of excitation coils is wound around the first magnetic axis, and at least one set of induction coils or at least one set of feedback coils is wound around the second magnetic axis; The current-carrying conductor is disposed through the cavity of the racetrack-shaped magnetic core, or is wound around the third magnetic axis or the fourth magnetic axis of the racetrack-shaped magnetic core.

[0010] In the embodiment of the present invention, there are two current-carrying conductors, and the two current-carrying conductors are respectively wound 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.

[0011] In the embodiment of the present 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 a region close to the magnetic core and is parallel to the magnetic core.

[0012] In the embodiment of the present invention, there are two rod-shaped magnetic cores; The current-carrying conductor is disposed between the two rod-shaped magnetic cores and is parallel to the two rod-shaped magnetic cores.

[0013] In the embodiments of the present invention, both the exciting coil and the induction coil are three-dimensional structures, and the exciting coil and the induction coil with three-dimensional structures are wound around the magnetic core in a helical manner.

[0014] In the embodiments of the present invention, the magnetic core is a thin-tape magnetic core, a thick-film magnetic core or a composite structure magnetic core made of soft magnetic materials, and the soft magnetic materials are permalloy, amorphous alloy or nanocrystalline alloy.

[0015] In the embodiments of the present invention, the magnetic core is a composite structure magnetic core made of two soft magnetic materials with different magnetic permeabilities; The feedback coil is wound around the magnetic core made of the soft magnetic material with the first magnetic permeability; The exciting coil and the induction coil are wound around the magnetic core made of the soft magnetic material with the second magnetic permeability.

[0016] In the embodiments of the present invention, when the induction coil is reused as the feedback coil, the magnetic field generated by the current-carrying conductor when connecting 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 realized by detecting the magnitude of the compensation current of the feedback coil.

[0017] In the embodiments of the present invention, there are at least two groups of exciting coils and at least two groups of induction coils, and every two groups of exciting coils and every two groups of induction coils are symmetrically distributed relative to the magnetic core.

[0018] In the embodiments of the present invention, when the same exciting current is applied to two symmetrically distributed exciting coils, the magnetic field directions generated by the two groups of exciting coils are the same. The magnetic field generated by the current-carrying conductor when connecting the current to be measured is converged by the magnetic core and then passes through the two groups of induction coils in opposite directions. By performing differential signal processing on the induction signals of the two groups of induction coils, the detection of the current to be measured is realized.

[0019] In the embodiments of the present invention, when the induction coil is reused as the feedback coil, a compensation current is applied to two symmetrically distributed feedback coils to cancel the magnetic field generated by the current to be measured, and the detection of the current to be measured is realized by detecting the magnitude of the compensation current of the feedback coil.

[0020] In the embodiments of the present invention, when the exciting coil is used as the induction coil, there are two current-carrying conductors. One of the current-carrying conductors is applied with an exciting current, and the magnetic field generated by the other current-carrying conductor connecting the current to be measured passes through two symmetrically distributed induction coils and has the same direction in the two groups of induction coils. By performing superimposed signal processing on the induction signals of the two groups of induction coils, the detection of the current to be measured is realized.

[0021] In an embodiment of the present invention, the coil only includes two induction coils, and the two induction coils are symmetrically wound around the magnetic core, and the two induction coils are connected in series.

[0022] When the same-direction exciting currents are applied to the two symmetrically distributed exciting coils, a magnetic field is generated by the current-carrying conductor when connecting 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 detection of the current to be measured is realized.

[0023] The present invention also provides a manufacturing method of the above-mentioned current sensing chip, including: Selecting three semiconductor wafers as the bottom substrate, the middle substrate and the top substrate respectively; Forming semi-cavities corresponding to the coil shape and semi-cavities corresponding to the current-carrying conductor shape on the bottom substrate and the top substrate; Forming a cavity for accommodating the magnetic core, a coil connection structure cavity and a current-carrying conductor connection structure cavity on the middle substrate; Filling the cavity for accommodating the magnetic core with magnetic material to form the magnetic core; Combining 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; Filling the three-dimensional spiral coil cavity with coil material to form a three-dimensional spiral coil wound around the magnetic core, and filling the connected current-carrying conductor cavity with conductor material to form the current-carrying conductor.

[0024] In another embodiment, two semiconductor wafers are selected as the bottom substrate and the top substrate respectively; Forming a cavity for accommodating the magnetic core, a semi-cavity corresponding to the coil shape and a semi-cavity corresponding to the current-carrying conductor shape on the bottom substrate and the top substrate; Filling the cavity for accommodating the magnetic core with magnetic material to form the magnetic core; Combining the bottom 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; Filling the three-dimensional spiral coil cavity with coil material to form a three-dimensional spiral coil wound around the magnetic core, and filling the connected current-carrying conductor cavity with conductor material to form the current-carrying conductor.

[0025] In an embodiment of the present invention, forming a cavity for accommodating the magnetic core, a semi-cavity corresponding to the coil shape and a semi-cavity corresponding to the current-carrying conductor shape on the bottom substrate, the middle substrate and the top substrate includes: Etching the bottom substrate to respectively form a cavity for accommodating the magnetic core, a semi-cavity corresponding to the coil shape and a semi-cavity corresponding to the current-carrying conductor shape; Etch the intermediate layer substrate to form a cavity for accommodating a magnetic core, a cavity for a coil connection structure, and a cavity for a corresponding current-carrying conductor connection structure respectively; Etch the top layer substrate to form the other half of the cavity corresponding to the coil shape and the other half of the cavity corresponding to the current-carrying conductor shape.

[0026] In the embodiment of the present invention, filling a magnetic material in the cavity for accommodating the magnetic core to form a magnetic core includes: placing a prefabricated thin-tape magnetic core, a thick-film magnetic core or a composite structure magnetic core in the cavity for accommodating the magnetic core, and the thin-tape magnetic core, the thick-film magnetic core and the composite structure magnetic core are processed from soft magnetic materials; Alternatively, deposit a magnetic material in the cavity for accommodating the magnetic core by an electroplating process to form a magnetic core.

[0027] In the embodiment of the present invention, the manufacturing method of the above current sensing chip further includes: After forming the magnetic core, form 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.

[0028] The current sensing chip provided by the present invention integrates a magnetic core, a coil and a current-carrying conductor on the same semiconductor substrate by using a microelectromechanical system (MEMS) process, and realizes current detection based on the fluxgate technology (magnetic modulation principle). The fluxgate technology is extremely sensitive to weak magnetic fields. Based on the three-dimensional coil and thick-film magnetic core integrated on the chip by MEMS technology, the magnetic field concentration efficiency can be improved, the magnetic circuit loss can be reduced, and the magnetic field of weak current can also be effectively captured. Therefore, the current sensing chip has high detection accuracy and good temperature stability, and can realize the detection of alternating current and direct current in the milliampere level and microampere level (μA~mA range). The magnetic core, coil and current-carrying conductor of the current sensing chip are integrated on the same semiconductor substrate by using a microelectromechanical system (MEMS) process, with high integration, small size, light weight, low power consumption and good consistency, realizing the chipization of the magnetic modulation type current sensor, which is beneficial to the integrated application and intelligent development of weak current sensors.

[0029] In addition, the current sensing chip of the present invention can adopt signal enhancement methods such as differential signal processing or superimposed signal processing, which can effectively suppress common-mode interference, improve the anti-interference ability, and can also realize a closed-loop current detection method at the chip level, with high detection accuracy, wide range, and significantly reduced volume and manufacturing cost of the sensor.

[0030] Other features and advantages of the technical solution of the present invention will be described in detail in the following specific implementation part. Description of the Drawings

[0031] The accompanying drawings described herein are used to provide a further understanding of the present invention, and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 is a schematic structural diagram of a current sensing chip provided in Embodiment 1 of the present invention; Figure 2 is a schematic structural diagram of another current sensing chip provided in Embodiment 1 of the present invention; Figure 3 is a schematic structural diagram of a current sensing chip provided in Embodiment 2 of the present invention; Figure 4 is a schematic structural diagram of a current sensing chip provided in Embodiment 3 of the present invention; Figure 5 is a schematic structural diagram of a current sensing chip provided in Embodiment 4 of the present invention; Figure 6 is a schematic structural diagram of a current sensing chip provided in Embodiment 5 of the present invention; Figure 7 is a schematic structural diagram of a current sensing chip provided in Embodiment 6 of the present invention; Figure 8 is a schematic diagram of the principle of the first detection method of the current sensing chip provided in the embodiments of the present invention; Figure 9 is a schematic diagram of the principle of the second detection method of the current sensing chip provided in the embodiments of the present invention; Figure 10 is a schematic diagram of the principle of the third detection method of the current sensing chip provided in the embodiments of the present invention; Figure 11 is a schematic diagram of the principle of the fourth detection method of the current sensing chip provided in the embodiments of the present invention; Figure 12 is a schematic diagram of the principle of the fifth detection method of the current sensing chip provided in the embodiments of the present invention; Figure 13 is a schematic structural diagram of a current sensing chip provided in Embodiment 7 of the present invention; Figure 14 is a schematic structural diagram of another current sensing chip provided in Embodiment 7 of the present invention; Figure 15 is a schematic diagram of the principle of the detection method of the current sensing chip provided in Embodiment 7 of the present invention; Figure 16 is a flowchart of the manufacturing method of the current sensing chip provided in the embodiments of the present invention.

[0032] Description of Reference Numerals 1 - Substrate, 2 - Magnetic core, 2 - 1 - Magnetic core with the first magnetic permeability, 2 - 2 - Magnetic core with the second magnetic permeability, 3 - Excitation coil, 3 - 1 - The first group of excitation coils, 3 - 2 - The second group of excitation coils; 4 - Induction coil, 4 - 1 - The first group of induction coils, 4 - 2 - The second group of induction coils, 5 - Current - carrying conductor, 5 - 1 - The first current - carrying conductor, 5 - 2 - The second current - carrying conductor, 7 - Feedback coil. Detailed implementation manners

[0033] In order to make the technical solutions and advantages in the embodiments of the present invention clearer and more understandable, the following further describes the exemplary embodiments of the present invention in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than an exhaustive list of all embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0034] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0035] Existing Hall current sensors and magnetoresistive current sensors still need to be further improved in terms of sensitivity, measurement accuracy, temperature stability, etc., and cannot meet the requirements for accurate measurement of small currents from micro - amperes to milliamperes. Magnetomodulation current sensors have high accuracy and good temperature stability, and have unique advantages in detecting weak currents in the milliampere or micro - ampere level. Traditional magnetomodulation current sensors are made by winding enameled wires around magnetic cores, which have problems such as uneven coil winding and poor consistency, and are large in volume and high in power consumption, which is not conducive to the integration and intelligent development of small - current sensors.

[0036] An embodiment of the present invention provides a current sensing chip based on the principle of magnetic modulation, which includes a magnetic core, a coil, and a current-carrying conductor. The magnetic core, the coil, and the current-carrying conductor are formed on the same semiconductor substrate based on the microelectromechanical system (MEMS) process. The magnetic core includes at least one independent magnetic core or composite structure magnetic core composed of soft magnetic materials. The current-carrying conductor includes at least one, which 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. The excitation coils and the induction coils are both wound around the magnetic core, and the excitation coils and the induction coils can both be reused as feedback coils. When the current-carrying conductor is connected to the current to be measured, the magnetic field generated by the current to be measured around the current-carrying conductor acts on the magnetic core to cause a change in magnetic flux, and the measurement of the current to be measured is realized by detecting the output signal of the induction coil or the feedback coil.

[0037] The method for forming the magnetic core, the coil, and the current-carrying conductor on the same semiconductor substrate based on the microelectromechanical system (MEMS) process is as follows: forming a half-coil cavity and a half-current-carrying conductor cavity on the bottom substrate; forming a half-coil cavity and a half-current-carrying conductor cavity on the top substrate; forming a magnetic core cavity, a coil connection structure cavity, and a current-carrying conductor connection structure cavity on the bottom substrate or the top substrate; or forming a magnetic core cavity, a coil connection structure cavity, and a current-carrying conductor connection structure cavity on the intermediate substrate; filling the magnetic core cavity with magnetic materials 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 spiral coil cavity, and a connected current-carrying conductor cavity; filling the three-dimensional spiral coil cavity with coil materials to form a three-dimensional spiral coil wound around the magnetic core, and filling the connected current-carrying conductor cavity with conductor materials to form a current-carrying conductor.

[0038] The current sensing chip of the present invention is based on the principle of magnetic modulation, has high precision and good temperature stability, and can realize the detection of alternating current and direct current in the milliamperes level and microamperes level (μA~mA range). The magnetic core, the coil, and the current-carrying conductor of the current sensing chip are integrated on the same semiconductor substrate by using the microelectromechanical system (MEMS) process, with high integration, small volume, light weight, low power consumption, and good consistency, realizing the chipization of the magnetic modulation type current sensor, which is beneficial to the integrated application and intelligent development of weak current sensors. Moreover, the current sensing chip of the present invention can adopt signal enhancement methods such as differential signal processing or superimposed signal processing, which can effectively suppress common-mode interference, improve the anti-interference ability, and can also realize chip-level closed-loop current detection, with high detection precision, wide range, and significantly reduced volume and manufacturing cost of the sensor.

[0039] Embodiment 1 Figure 1 and Figure 2It is a schematic structural diagram of the current sensing chip provided in the first embodiment of the present invention. As Figure 1 and Figure 2 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 the MEMS process. Figure 1 The current-carrying conductor 5 is disposed through the cavity of the magnetic core 2, Figure 2 The current-carrying conductor 5 is wound around the magnetic core 2. The coil includes a set of excitation coils 3 and a set of induction coils 4, and both the excitation coils 3 and the induction coils 4 are wound around the magnetic core 2.

[0040] The shape of the magnetic core of the current sensing chip is annular, racetrack-shaped, rectangular, or rod-shaped. In this embodiment, the shape of the magnetic core 2 is racetrack-shaped.

[0041] The number of current-carrying conductors of the current sensing chip can be one, two, or more. Figure 1 In, the number of current-carrying conductors 5 is one, and one current-carrying conductor is disposed through the cavity of the racetrack-shaped magnetic core to enhance the magnetic flux concentrating effect of the magnetic core on the magnetic field generated by the current-carrying conductor.

[0042] In this embodiment, both the excitation coil and the induction coil are three-dimensional structures, and the three-dimensional excitation coil and induction coil are wound around the magnetic core in a spiral manner. Both the excitation coil and the induction coil can be reused as feedback coils. If the induction coil is used as the feedback coil, chip-level closed-loop current detection can be achieved through the feedback coil.

[0043] In this embodiment, the magnetic core is a thin-tape magnetic core or a thick-film magnetic core made of soft magnetic material, which is a high-permeability magnetic core. The soft magnetic material is permalloy, amorphous alloy, or nanocrystalline alloy, etc.

[0044] The current sensing chip of this embodiment is based on the magnetic modulation principle (fluxgate principle), and realizes the indirect measurement of the current to be measured by using the magnetic field modulation effect of the high-permeability magnetic core in the periodic saturation state. The current sensing chip of the present invention can be combined with the actual application requirements, and two methods are adopted to achieve AC and DC detection in the range of μA~mA, improving the flexibility of detection.

[0045] The first detection method is as Figure 8 shown, an excitation current i ex is applied to the excitation coil, and the current-carrying conductor generates a magnetic field H0 when connected to the current to be measured I p . The magnetic field H0 causes a change in the magnetic flux passing through the induction coil, and the current to be measured is detected by detecting the induced voltage signal of the induction coil.

[0046] The second detection method is as Figure 9As shown, when the induction coil is used as a feedback coil, an excitation current is applied to the excitation coil i ex , the current-carrying conductor generates a magnetic field H0 when connecting to the current I to be measured p . The magnetic field H0 causes a change in the magnetic flux passing through the induction coil, and 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 i co .

[0047] The current sensing chip provided in this embodiment uses fluxgate technology to achieve current detection. Fluxgate technology is extremely sensitive to weak magnetic fields. Based on MEMS technology, three-dimensional coils and thick-film magnetic cores integrated on the chip can improve the magnetic field concentration efficiency and reduce magnetic circuit losses, enabling weak current magnetic fields to be effectively captured. Based on the Figure 1 shown current sensing chip structure for model simulation, the simulation results show that this structure can achieve mA-level current detection. Based on the Figure 2 shown current sensing chip structure for model simulation, the simulation results show that this structure can achieve μA-level current detection

[0048] Embodiment 2 Figure 3 is a schematic structural diagram of the current sensing chip provided in Embodiment 2 of the present invention. As Figure 3 shown, the current sensing chip provided in this embodiment includes a magnetic core, coils, and a current-carrying conductor. The magnetic core 2, coils, and current-carrying conductor 5 are formed on the same semiconductor substrate 1 based on MEMS technology. The coils include 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 around the magnetic core in a spiral manner. The shape of the magnetic core 2 is a racetrack type. The racetrack-shaped magnetic core has a symmetric first magnetic axis and second magnetic axis, and symmetric third magnetic axis and fourth magnetic axis. A set of excitation coils and a set of induction coils are wound around the first magnetic axis, and a set of feedback coils are wound around the second magnetic axis

[0049] Different from Embodiment 1, Embodiment 2 includes a set of feedback coils 7. The current sensing chip of Embodiment 2 can use the above-mentioned second detection method to measure the current to be measured. Specifically, an excitation current is applied to the excitation coil i ex , the current-carrying conductor generates a magnetic field H0 when connecting to the current I to be measured p . The magnetic field H0 causes a change in the magnetic flux passing through the induction coil, and a compensation current is applied to the feedback coil i co, offset the change in magnetic flux caused by the magnetic field H0, and detect the current to be measured by detecting the compensation current of the feedback coil i co magnitude to achieve the detection of the current to be measured.

[0050] Embodiment III Figure 4 is a schematic structural diagram of the current sensing chip provided by Embodiment III of the present invention. As Figure 4 shown, the current sensing chip provided in this embodiment includes a magnetic core, a coil, and a current-carrying conductor. The magnetic core, the coil, and the current-carrying conductor 5 are formed on the same semiconductor substrate 1 based on the MEMS process. 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, induction coils, and feedback coils are all three-dimensional structures, and the three-dimensional excitation coils, induction coils, and feedback coils are wound around the magnetic core in a helical manner.

[0051] Different from Embodiment II, the magnetic core in Embodiment III is a composite magnetic core, which is a composite structure composed of two soft magnetic materials with different magnetic permeabilities. The magnetic core includes a magnetic core made of a soft magnetic material with the first magnetic permeability and a magnetic core made of a soft magnetic material with the second magnetic permeability. The feedback coil 7 is wound around the magnetic core 2-1 with the first magnetic permeability, and the excitation coil 3 and the induction coil 4 are wound around the magnetic core 2-2 with the second magnetic permeability.

[0052] The current sensing chip in Embodiment III can measure the current to be measured by using the above-mentioned second detection method. Specifically, an excitation current is applied to the excitation coil i ex , the current-carrying conductor generates a magnetic field H0 when connecting the current to be measured I p , the magnetic field H0 causes a change in the magnetic flux passing through the induction coil, and a compensation current is applied to the feedback coil i co , offset the change in magnetic flux caused by the magnetic field H0, and detect the current to be measured by detecting the compensation current of the feedback coil i co magnitude to achieve the detection of the current to be measured.

[0053] Embodiment IV Figure 5 is a schematic structural diagram of the current sensing chip provided by Embodiment IV of the present invention. As Figure 5 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 the MEMS process. The coil includes two sets of excitation coils: the first set of excitation coils 3-1, the second set of excitation coils 3-2, and two sets of induction coils: the first set of induction coils 4-1, the second set of induction coils 4-2. The two sets of excitation coils and the two sets of induction coils are all wound around the magnetic core.

[0054] Different from the first embodiment, there are two sets of exciting coils and induction coils in the fourth embodiment. The first set of exciting coils 3-1 and the second set of exciting coils 3-2 are symmetrically distributed relative to the magnetic core 2, and the first set of induction coils 4-1 and the second set of induction coils 4-2 are symmetrically distributed relative to the magnetic core 2. Both the exciting coils and the induction coils are three-dimensional structures, and the three-dimensional exciting coils and induction coils are wound around the magnetic core in a spiral manner. The shape of the magnetic core 2 is a racetrack type. The racetrack-shaped magnetic core has a symmetric first magnetic axis and second magnetic axis, and symmetric third magnetic axis and fourth magnetic axis. The first set of exciting coils 3-1 and the first set of induction coils 4-1 are wound around the first magnetic axis, and the second set of exciting coils 3-2 and the second set of induction coils 4-2 are wound around the second magnetic axis. The current-carrying conductor 5 is disposed through the cavity of the racetrack-shaped magnetic core.

[0055] The current sensing chip of this embodiment is based on the magnetic modulation principle (fluxgate principle), and realizes the indirect measurement of the current to be measured by using the magnetic field modulation effect of a high-permeability magnetic core in a periodic saturation state. The current sensing chip of the present invention can be combined with the actual application requirements, and adopts the third detection method and the fourth detection method to realize the AC and DC detection in the range of μA~mA, improving the flexibility of detection.

[0056] The third detection method is as Figure 10 shown, applying exciting currents in the same direction to the two sets of symmetrically distributed exciting coils i ex , and the magnetic fields H ex generated by the two sets of exciting coils have the same direction. When the current-carrying conductor is connected to the current to be measured I p , a magnetic field H0 is generated. After the magnetic field H0 is converged by the magnetic core, the magnetic field directions passing through the upper and lower two sets of induction coils are opposite. By performing differential signal processing on the induction signals of the two sets of induction coils, that is, the chip output signal V out = V out1 - V out2 , it can not only eliminate the induced electromotive force generated by the exciting coil due to the transformer effect, but also enhance the change of the induced electromotive force in the induction coil caused by the magnetic field generated by the current to be measured, and can also effectively suppress the common-mode interference and improve the anti-interference ability, so as to realize the accurate detection of the current to be measured.

[0057] The fourth detection method is as Figure 11 shown, the two sets of induction coils are used as feedback coils, and applying exciting currents in the opposite direction to the two sets of symmetrically distributed exciting coils i ex , and the magnetic fields H ex generated by the two sets of exciting coils have opposite directions. When the current-carrying conductor is connected to the current to be measured I p , a magnetic field H0 is generated. Applying a compensation current i co, offset the change in magnetic flux caused by the magnetic field H0, and detect the current to be measured by detecting the magnitude of the compensation current in the feedback coil.

[0058] Embodiment Five Figure 6 is a schematic structural diagram of the current sensing chip provided in Embodiment Five of the present invention. As Figure 6 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 based on the MEMS process. The coils include two sets of excitation coils 3-1, 3-2 and two sets of induction coils 4-1, 4-2. The two sets of excitation coils and the two sets of induction coils are all wound around 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 symmetrically distributed with respect to the magnetic core 2. There are two current-carrying conductors, including the first current-carrying conductor 5-1 and the second current-carrying conductor 5-2. The excitation coils and the induction coils are all three-dimensional structures, and the three-dimensional excitation coils and induction coils are wound around the magnetic core in a spiral manner. The shape of the magnetic core 2 is a racetrack type. The racetrack-shaped magnetic core has a symmetric first magnetic axis and a second magnetic axis, and a symmetric third magnetic axis and a fourth magnetic axis. One set of excitation coils and one set of induction coils are wound around the first magnetic axis, and the other set of excitation coils and the other set of induction coils are wound around the second magnetic axis.

[0059] Different from Embodiment Four, the number of current-carrying conductors in Embodiment Five is two. 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 a region close to the magnetic core and is parallel to the magnetic core. The two current-carrying conductors can enhance the magnetic flux concentration effect of the magnetic core on the magnetic field generated by the current-carrying conductors.

[0060] The current sensing chip of this embodiment is based on the magnetic modulation principle (fluxgate principle), and indirectly measures the current to be measured by using the magnetic field modulation effect of the high-permeability magnetic core in the periodic saturation state. The current sensing chip of this embodiment can be combined with the actual application requirements, and adopt the fifth detection method (both current-carrying conductors are connected to the current to be measured) to achieve AC and DC detection in a wide range of mA~A.

[0061] The fifth detection method is as Figure 12 shown. An excitation current is applied through the first current-carrying conductor 5-1 i ex , at this time, all the coils wound around the magnetic core are used as induction coils (the excitation coils also serve as induction coils). The magnetic field H ex generated by the first current-carrying conductor 5-1 under the excitation current passes through the upper and lower two sets of induction coils, and the directions in the two sets of induction coils are opposite. The second current-carrying conductor 5-2 is connected to the current to be measured Ip, and the current to be measured I pThe generated magnetic field H0 passes through the upper and lower sets of induction coils and has the same direction in the two sets of induction coils. The induction signals of the two sets of induction coils are processed as a superimposed signal, that is, the chip output signal V out =V out1 +V out2 , which can not only eliminate the induced electromotive force generated by the excitation coil due to the transformer effect, but also enhance the change of the induced electromotive force in the induction coil caused by the magnetic field generated by the current to be measured, so as to achieve accurate detection of the current to be measured.

[0062] Embodiment Six Figure 7 is a schematic structural diagram of the current sensing chip provided in Embodiment Six of the present invention. As Figure 7 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 based on the MEMS process. The coils include two sets of excitation coils 3-1, 3-2 and two sets of induction coils 4-1, 4-2. The two sets of excitation coils and the two sets of induction coils are all wound around the magnetic core. 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, and the first set of induction coils 4-1 and the second set of induction coils 4-2 are symmetrically distributed relative to the magnetic core 2. There are two current-carrying conductors, including the first current-carrying conductor 5-1 and the second current-carrying conductor 5-2. The excitation coils and the induction coils are all three-dimensional structures, and the three-dimensional excitation coils and induction coils are wound around the magnetic core in a spiral manner. The shape of the magnetic core 2 is a racetrack type. The racetrack-shaped magnetic core has a symmetric first magnetic axis and a second magnetic axis, and symmetric third magnetic axis and fourth magnetic axis. One set of excitation coils and one set of induction coils are wound around the first magnetic axis, and the other set of excitation coils and the other set of induction coils are wound around the second magnetic axis. Figure 7 In, the two current-carrying conductors are arranged through the cavity of the racetrack-shaped magnetic core. In addition, there is another arrangement: the two current-carrying conductors are respectively wound around the third magnetic axis and the fourth magnetic axis of the magnetic core (not shown in the drawings).

[0063] Different from Embodiment Five, in Embodiment Six, the two current-carrying conductors are arranged 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 magnetic axis and the fourth magnetic axis 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 magnetic axis and the fourth magnetic axis of the magnetic core to enhance the magnetic focusing effect.

[0064] The current sensing chip of this embodiment can adopt the above first, second, third and fourth detection methods. The two current-carrying conductors are both connected to the current to be measured and are used to measure the residual current of two wires, so as to achieve complex residual current detection in the range of μA~mA.

[0065] Embodiment Seven Figure 13 and Figure 14 is a schematic structural diagram of the current sensing chip provided in the seventh embodiment of the present invention. As Figure 13 and Figure 14 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 around the magnetic core 2. The 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 through wires. The two sets of induction coils serve as both inputs and outputs at the same time. Figure 13 In Figure 14 the shape of the magnetic core 2 is annular,

[0066] As Figure 15 shown, when using this current sensing chip for current detection, when the same excitation current i ex is applied to the two symmetrically distributed excitation coils, a magnetic field H0 is generated when the current-carrying conductor is connected to the current to be measured Ip. Under the action of the magnetic field H0, the magnetic flux passing through the induction coil changes, and the induced voltage signal V out of the induction coil is detected, thereby realizing the detection of the current Ip to be measured.

[0067] The current sensing chip provided in the above embodiment is composed of a wafer substrate, a micro magnetic core, a spiral coil and a current-carrying conductor. The three-dimensional spiral coil is wound around the micro magnetic core. The coil height can reach several hundred micrometers, which can accommodate a magnetic core structure with a larger cross-sectional area, improving the current detection sensitivity. The current-carrying conductor passes through the magnetic core or is arranged parallel to the magnetic core closely, significantly enhancing the magnetic flux concentration effect and reducing the lower limit of current detection. The micro magnetic core, spiral coil and current-carrying conductor are fabricated by microelectromechanical system technology on the same wafer substrate, realizing the chipization of the small current sensor, with high production efficiency and good consistency.

[0068] The current sensing chip provided in the above embodiment uses fluxgate technology to realize current detection. Fluxgate technology is extremely sensitive to weak magnetic fields. Based on MEMS technology, the three-dimensional coil and thick film magnetic core integrated on the chip can improve the magnetic field concentration efficiency and reduce the magnetic circuit loss, enabling the magnetic field of weak current to be effectively captured. Therefore, this chip can meet the requirements of wide-range, high-precision and high-bandwidth AC and DC current detection from microamps to amperes.

[0069] The current sensing chip provided in the embodiment of the present invention has the magnetic core, coil and current-carrying conductor fabricated by microelectromechanical system technology on the same wafer substrate, and the thickness of the magnetic core can reach 200 - 300μm. The three-dimensional spiral coil is wound around the micro magnetic core, and the coil height can reach several hundred micrometers, which can accommodate a magnetic core structure with a larger cross-sectional area, and can significantly improve the current detection sensitivity.

[0070] Embodiments of the present invention also provide a manufacturing method of the above-mentioned current sensing chip. As Figure 16 shown, the manufacturing method of the current sensing chip includes the following steps: S121, select three semiconductor wafers as the bottom substrate, the middle substrate, and the top substrate respectively; S122, form semi-cavities corresponding to the coil shape and semi-cavities corresponding to the shape of the current-carrying conductor on the bottom substrate and the top substrate; S123, form a cavity for accommodating the magnetic core, a coil connection structure cavity, and a current-carrying conductor connection structure cavity on the middle substrate; S124, fill the cavity for accommodating the magnetic core with a magnetic material to form a magnetic core; S125, combine 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; S126, fill the three-dimensional spiral coil cavity with a coil material to form a three-dimensional spiral coil wound around the magnetic core, and fill the connected current-carrying conductor cavity with a conductor material to form a current-carrying conductor.

[0071] In the above step S121, the selected wafers are made of materials such as silicon, silicon dioxide, or silicon on insulator (SOI).

[0072] In the above steps S122 and S123, the bottom substrate is etched to form semi-cavities corresponding to the coil shape and semi-cavities corresponding to the shape of the current-carrying conductor respectively; the middle substrate is etched to form a cavity for accommodating the magnetic core, a coil connection structure cavity, and a corresponding current-carrying conductor connection structure cavity respectively; the top substrate is etched to form the other half of the semi-cavities corresponding to the coil shape and the other half of the semi-cavities corresponding to the shape of the current-carrying conductor.

[0073] In the above step S124, a prefabricated thin-ribbon magnetic core, thick-film magnetic core, or composite structure magnetic core is placed in the cavity for accommodating the magnetic core on the middle substrate, or a magnetic material is deposited in the cavity for accommodating the magnetic core by electroplating to form a magnetic core. The materials of the thin-ribbon magnetic core and the thick-film magnetic core can be soft magnetic materials. For example, a thin-ribbon magnetic core made by laser cutting of a strip can be used, or a thick-film magnetic core made by precision machining after bonding and curing of a strip can be used.

[0074] In the above step S126, a coil material is filled in the three-dimensional spiral coil cavity to form a three-dimensional spiral coil wound around the magnetic core, and a conductor material is filled in the connected current-carrying conductor cavity to form a current-carrying conductor. The coil material and the conductor material can be a single metal material or an alloy material.

[0075] The manufacturing method of the above-mentioned current sensing chip 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.

[0076] In another embodiment, the manufacturing method of the above-mentioned current sensing chip includes the following steps: Select two semiconductor wafers as the bottom substrate and the top substrate respectively; Form cavities for accommodating the magnetic core, semi-cavities corresponding to the shape of the coil, and semi-cavities corresponding to the shape of the current-carrying conductor on the bottom substrate and the top substrate; or, etch on the top substrate to form a cavity for accommodating the magnetic core; Fill the cavity for accommodating the magnetic core with a magnetic material to form a magnetic core; Bond the bottom substrate and the top substrate to form a closed magnetic core cavity, a three-dimensional spiral-shaped coil cavity, and a connected current-carrying conductor cavity; Fill the three-dimensional spiral-shaped coil cavity with a coil material to form a three-dimensional spiral coil wound around the magnetic core, and fill the connected current-carrying conductor cavity with a conductor material to form a current-carrying conductor.

[0077] Specifically, place a prefabricated thin-tape magnetic core, thick-film magnetic core, or composite structure magnetic core in the cavity for accommodating the magnetic core. The thin-tape magnetic core, thick-film magnetic core, and composite structure magnetic core are processed from soft magnetic materials. Or, deposit a magnetic material in the cavity for accommodating the magnetic core by electroplating process to form a magnetic core.

[0078] After forming the magnetic core, form 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.

[0079] The current sensing chip preparation method provided by the embodiments of the present invention does not rely on the electroplating process, has better compatibility with the large-scale integrated circuit process, and realizes the chipization and wafer-level manufacturing of small current sensors. Specifically, the current sensing chip and preparation method of the present invention have the following advantages: (1) This chip does not need to be combined with the traditional magnetic concentrating ring structure. The magnetic core, coil, and current-carrying wire are integrated on the same wafer substrate through the MEMS process, with high integration, and can effectively solve the problems of large volume, heavy weight, high cost, and poor consistency of existing small current sensors; (2) This chip adopts the electromagnetic induction or magnetic modulation principle, with high measurement accuracy, and can meet the measurement of small alternating and direct currents in the microampere to ampere range; (3) This chip can adopt differential signal processing, can effectively suppress common-mode interference, and improve the anti-interference ability; (4) This chip can provide chip-level closed-loop current detection, can achieve high-precision, high-bandwidth, and wide-range current detection, and significantly reduce the volume and cost of the sensor.

[0080] The optional embodiments of the present invention have been described in detail above in conjunction with 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. In addition, it should be noted that, among the various specific technical features described in the above specific embodiments, without conflict, they can be combined in any appropriate manner, as long as this combination does not violate the idea of the embodiments of the present invention, and it should also be regarded as the content disclosed by 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 composed of soft magnetic materials, and the current - carrying conductor is arranged in the area 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 induction coils and the excitation coils are wound around the magnetic core, and both the excitation coils and the induction coils can be reused as feedback coils; The magnetic core, the coil, and the current - carrying conductor are formed on the same semiconductor substrate, and the forming method includes: Form a semi - coil cavity and a semi - current - carrying conductor cavity on the bottom - layer substrate; Form a semi - coil cavity and a semi - current - carrying conductor cavity on the top - layer substrate; Form a magnetic - core cavity, a coil - connection - structure cavity, and a current - carrying - conductor - connection - structure cavity on the bottom - layer substrate or the top - layer substrate; or, form a magnetic - core cavity, a coil - connection - structure cavity, and a current - carrying - conductor - connection - structure cavity on the middle - layer substrate; Fill the magnetic - core cavity with magnetic materials to form a magnetic core; Combine the bottom - layer substrate and the top - layer substrate, or combine the bottom - layer substrate, the middle - layer substrate, and the top - layer substrate to form a closed magnetic - core cavity, a three - dimensional spiral - shaped coil cavity, and a connected current - carrying conductor cavity; Fill the three - dimensional spiral - shaped coil cavity with coil materials to form a three - dimensional spiral coil wound around the magnetic core, and fill the connected current - carrying conductor cavity with conductor materials to form a current - carrying conductor.

2. The current sensing chip according to claim 1, wherein The shape of the magnetic core is annular, racetrack - shaped, rectangular, or rod - shaped.

3. The current sensing chip according to claim 2, characterized in that, The racetrack - shaped magnetic core has a symmetric first magnetic axis and a second magnetic axis, and a symmetric third magnetic axis and a fourth magnetic axis; At least one set of excitation coils is wound around the first magnetic axis, and at least one set of induction coils or at least one set of feedback coils is wound around the second magnetic axis; [[ID= 4. The current sensing chip according to claim 3, wherein, ​ 5. The current sensing chip according to claim 3, characterized in that, ​ 6. The current sensing chip according to claim 2, wherein ​ ​ 7. The current sensing chip according to claim 1, wherein ​ 8. The current sensing chip according to claim 1, wherein ​ 9. The current sensing chip according to claim 1, characterized in that, ​ ​ ​ 10. The current sensing chip according to claim 1, characterized in that, ​ 11. The current sensing chip according to claim 1, characterized in that, There are at least two sets of exciting coils and at least two sets of induction coils, and every two sets of exciting coils and every two sets of induction coils are symmetrically distributed with respect to the magnetic core.

12. The current sensing chip according to claim 11, wherein, The current-carrying conductor generates a magnetic field when connecting to the current to be measured. When the same-direction exciting currents are applied to two symmetrically distributed sets of exciting coils, the magnetic field directions generated by the two sets of exciting coils are the same. After converging by the magnetic core, the magnetic field directions passing through the two sets of induction coils are opposite. 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 realized.

13. The current sensing chip according to claim 12, wherein 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 detection of the current to be measured is realized by detecting the magnitude of the compensation current of the feedback coil.

14. The current sensing chip according to claim 11, wherein, There are two current-carrying conductors. An exciting current is applied to one of the current-carrying conductors. The exciting coil serves as an induction coil. The magnetic field generated by the other current-carrying conductor connecting to the current to be measured passes through two symmetrically distributed sets of induction coils, and the directions in the two sets of induction coils are the same. By performing superposition signal processing on the induction signals of the two sets of induction coils, the detection of the current to be measured is realized.

15. The current sensing chip according to claim 1, characterized in that, The coil only includes two sets of induction coils. The two sets of induction coils are symmetrically wound around the magnetic core, and the two sets of induction coils are connected in series.

16. The current sensing chip according to claim 15, characterized in that, When the same-direction exciting currents are applied to two symmetrically distributed sets of exciting coils, the current-carrying conductor generates a magnetic field when connecting 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 induction voltage signal of the induction coil, the detection of the current to be measured is realized.

17. A manufacturing method of a current sensing chip, characterized in that, Including: Select three semiconductor wafers as the bottom substrate, the middle substrate, and the top substrate respectively; Form semi-cavities corresponding to the coil shape and semi-cavities corresponding to the current-carrying conductor shape on the bottom substrate and the top substrate; Form a cavity for accommodating the magnetic core, a coil connection structure cavity, and a current-carrying conductor connection structure cavity on the middle substrate; Fill the cavity for accommodating the magnetic core with magnetic material to form the magnetic core; Combine the bottom substrate, the middle substrate, and the top substrate to form a closed magnetic core cavity, a three-dimensional spiral-shaped coil cavity, and a connected current-carrying conductor cavity; Fill the three-dimensional spiral-shaped coil cavity with coil material to form a three-dimensional spiral coil wound around the magnetic core, and fill the connected current-carrying conductor cavity with conductor material to form the current-carrying conductor; Or, the method includes: Select two semiconductor wafers as the bottom substrate and the top substrate respectively; Form a cavity for accommodating the magnetic core, semi-cavities corresponding to the coil shape, and semi-cavities corresponding to the current-carrying conductor shape on the bottom substrate and the top substrate; Fill the cavity for accommodating the magnetic core with magnetic material to form the magnetic core; Combine the bottom substrate and the top substrate to form a closed magnetic core cavity, a three-dimensional spiral-shaped coil cavity, and a connected current-carrying conductor cavity; Fill the three-dimensional spiral-shaped coil cavity with coil material to form a three-dimensional spiral coil wound around the magnetic core, and fill the connected current-carrying conductor cavity with conductor material to form the current-carrying conductor.

18. The manufacturing method of the current sensing chip according to claim 17, characterized in that, Filling the cavity for accommodating the magnetic core with magnetic material to form the magnetic core includes: Place a prefabricated thin-tape magnetic core, thick-film magnetic core or composite structure magnetic core made of soft magnetic material in a cavity for accommodating a magnetic core; Alternatively, deposit a magnetic material in a cavity for accommodating a magnetic core by an electroplating process to form a magnetic core.

19. The manufacturing method of the current sensing chip according to claim 17, wherein The method further includes: After forming the magnetic core, form an insulating protective layer on the surface of the magnetic core to isolate the magnetic core from a coil and the magnetic core from a current-carrying conductor.

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