Magnetic sensor chip sensitivity temperature drift testing device and testing method

Abstract

The present application relates to the field of magnetic sensing chip detection, and provides a kind of magnetic sensing chip sensitivity temperature drift testing device and testing method.The device includes: temperature box, temperature drift testing module and signal acquisition module, the temperature drift testing module is arranged in temperature box, and the signal acquisition module is connected with the temperature drift testing module;The temperature drift testing module includes m magnetic field generating modules, each magnetic field generating module includes permanent magnet holder and multiple permanent magnets, the permanent magnet holder is provided with the through hole for accommodating the magnetic sensing chip to be measured and standard magnetic sensing chip, and multiple permanent magnets are placed in the permanent magnet holder on both sides of the through hole;The signal acquisition module has m channels, for simultaneously collecting the output signal of the magnetic sensing chip to be measured and standard magnetic sensing chip corresponding to m magnetic field generating modules.By the present application, the sensitivity temperature drift test of linear magnetic sensitive sensing chip can be realized at low cost and high efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of magnetic sensing chip detection, in particular to a magnetic sensing chip sensitivity temperature drift test device and a magnetic sensing chip sensitivity temperature drift test method. BACKGROUND

[0002] Linear magnetic sensitive sensor chips such as Hall chips and tunneling magnetoresistance chips can indirectly measure position, angle, current and other physical quantities by measuring magnetic field, and are widely used in electric vehicles, photovoltaic inverters, industrial control and intelligent instruments. The magnetic field sensitive part of the Hall chip is generally made of semiconductor material, and its magnetic field measurement principle is based on the Hall effect of semiconductor material. When the temperature changes, the physical parameters such as electrical conductivity and carrier mobility of the semiconductor material will change, which will affect the strength of the Hall effect, causing the magnetic field sensitivity of the Hall chip to drift with temperature. The physical properties of the sensitive material in the tunneling magnetoresistance chip are also affected by temperature changes, which will affect the resistance state of the magnetic tunnel junction, thereby causing the tunneling magnetoresistance effect to drift with temperature. In addition, the chip packaging and manufacturing process will also introduce additional temperature dependence to the magnetic sensitive sensor chip.

[0003] In engineering applications, sensitivity temperature drift is one of the important factors that limit the actual performance of magnetic sensitive sensor chips such as Hall chips and tunneling magnetoresistance chips, and can be reduced by temperature drift compensation. When temperature drift compensation is performed, the sensitivity temperature drift characteristics of the magnetic sensitive sensor chip need to be tested first to obtain the temperature drift curve and temperature drift coefficient. The commonly used method is to use a coil to generate a test magnetic field, and then place the coil and the test sample in a high-low temperature chamber to realize the sensitivity temperature drift test. Due to the large volume and weight of the coil, a temperature chamber with a large internal space is required, and the load-bearing capacity of the internal structure of the temperature chamber is also required to be high. In addition, a large current needs to be passed through the coil to generate a magnetic field with sufficient strength, which causes the coil to generate a large amount of heat. When testing at high temperature (such as 125℃~150℃), the heat inside the coil is not easy to dissipate and will continue to accumulate, making it impossible to continuously output the magnetic field for a long time. The existing sensitivity temperature drift test device is limited by the size of the internal space of the temperature chamber, and the volume of the coil cannot be too large. When testing at high temperature, the heat accumulation problem also makes the current of the coil cannot be too large. The limitation of the volume and current of the coil makes the magnetic field strength generated by the coil at high temperature not very large, and the effective duration of the high temperature test cannot be too long, which makes it impossible to directly test the sensitivity temperature drift of the magnetic sensitive sensor chip in a large range, and only the sensitivity temperature drift characteristics in a small range can be indirectly calculated from the test results. The temperature drift characteristics in a large range and in a small range are not necessarily consistent, and this indirect calculation method has deviations. SUMMARY

[0004] In order to solve the above technical defects, the present application provides a magnetic sensing chip sensitivity temperature drift test device and test method.

[0005] The application provides a magnetic sensor chip sensitivity temperature drift test device, which comprises a temperature box, a temperature drift test module and a signal acquisition module.

[0006] The temperature drift test module comprises m magnetic field generating modules, each of which comprises a permanent magnet holder and a plurality of permanent magnets.

[0007] The signal acquisition module has m channels for simultaneously collecting output signals of the m magnetic field generating modules.

[0008] In the application, the permanent magnet holder of each magnetic field generating module can accommodate at least one magnetic sensor chip and one standard magnetic sensor chip.

[0009] The standard magnetic sensor chip is a calibrated and calibrated magnetic sensor chip.

[0010] In the application, the wires of the plurality of permanent magnets pass through the magnetic sensitive area of the magnetic sensor chip in the through hole of the permanent magnet holder.

[0011] In the application, the magnetization direction of the permanent magnet is perpendicular to the plane of the permanent magnet holder.

[0012] In the application, the permanent magnet holder is provided with a plurality of permanent magnet card slots, and the plurality of permanent magnets are respectively arranged in the plurality of permanent magnet card slots.

[0013] In the application, the shape of the permanent magnet is circular or square, and the shape of the permanent magnet card slot matches the shape of the permanent magnet.

[0014] In the application, the material of the permanent magnet is a low temperature coefficient permanent magnet material, and the absolute value of the temperature coefficient of the material of the permanent magnet is not more than 0.05% / ℃.

[0015] In the application, the temperature drift test module further comprises a circuit board.

[0016] The circuit board is provided with a plurality of chip bases for mounting magnetic sensor chips.

[0017] The chip base corresponds to the through hole of the permanent magnet holder, so that the magnetic sensor chip on the chip base is in the through hole.

[0018] In the embodiment of the present application, the circuit board is provided with a signal interface.

[0019] The signal interface has a plurality of pins corresponding to a plurality of channels of the signal acquisition module, and the output pins of the chip base are connected with the pins of the signal interface.

[0020] In the embodiment of the present application, the circuit board is provided with a power interface, the power interface is connected with a power supply outside the oven, and the power pins of the chip base are connected with the power interface.

[0021] In the embodiment of the present application, the magnetic field generating module is fixed on the circuit board through a first stud.

[0022] In the embodiment of the present application, the circuit board is fixed on the support plate in the oven through a second stud.

[0023] The present application also provides a magnetic sensor chip sensitivity temperature drift test method based on the above magnetic sensor chip sensitivity temperature drift test device, which comprises the following steps:

[0024] A reasonable number of permanent magnets are placed in the permanent magnet holder, so that the area where the to-be-tested magnetic sensor chip and the standard magnetic sensor chip are located in the through hole of the permanent magnet holder is in a full magnetic state; the target temperature of the oven is set to a reference temperature, a low temperature point temperature and a high temperature point temperature respectively, so that the to-be-tested magnetic sensor chip and the standard magnetic sensor chip are in a test environment of the reference temperature, the low temperature point temperature and the high temperature point temperature, and the output voltage values of the to-be-tested magnetic sensor chip and the standard magnetic sensor chip corresponding to each acquisition channel of the signal acquisition module are recorded.

[0025] The permanent magnets in the permanent magnet holder are taken out, so that the area where the to-be-tested magnetic sensor chip and the standard magnetic sensor chip are located in the through hole of the permanent magnet holder is in a zero magnetic state; the target temperature of the oven is set to a reference temperature, a low temperature point temperature and a high temperature point temperature respectively, so that the to-be-tested magnetic sensor chip and the standard magnetic sensor chip are in a test environment of the reference temperature, the low temperature point temperature and the high temperature point temperature, and the output voltage values of the to-be-tested magnetic sensor chip and the standard magnetic sensor chip corresponding to each acquisition channel of the signal acquisition module are recorded.

[0026] According to the output voltage values of the to-be-tested magnetic sensor chip and the standard magnetic sensor chip in the test environment of the reference temperature, the low temperature point temperature and the high temperature point temperature, the sensitivity temperature drift of the to-be-tested magnetic sensor chip is calculated.

[0027] In the embodiment of the present application, after setting the target temperature of the oven to the reference temperature, the low temperature point temperature or the high temperature point temperature, at least 10 minutes are waited after the oven reaches the set temperature, so that the to-be-tested magnetic sensor chip and the standard magnetic sensor chip reach a thermal equilibrium state with the inside of the oven.

[0028] In the embodiment of the present application, the sensitivity temperature drift of the to-be-tested magnetic sensor chip is calculated according to the output voltage values of the to-be-tested magnetic sensor chip and the standard magnetic sensor chip in the test environment of the reference temperature, the low temperature point temperature and the high temperature point temperature, and the sensitivity temperature drift of the to-be-tested magnetic sensor chip comprises:

[0029] Supposing that the reference temperature is T1, the low temperature point temperature is T2 and the high temperature point temperature is T3, the sensitivities of the to-be-tested magnetic sensor chip in the reference temperature T1, the low temperature point temperature T2 and the high temperature point temperature T3 are K1, K2 and K3 respectively, and the sensitivity of the standard magnetic sensor chip is K';

[0030] In the full magnetic state, the output voltage values of the to-be-tested magnetic sensor chip in the reference temperature T1, the low temperature point temperature T2 and the high temperature point temperature T3 are U1, U2 and U3 respectively, and the output voltage values of the standard magnetic sensor chip are U1', U2' and U3' respectively;

[0031] In the zero magnetic state, the output voltage values of the to-be-tested magnetic sensor chip in the reference temperature T1, the low temperature point temperature T2 and the high temperature point temperature T3 are V1, V2 and V3 respectively, and the output voltage values of the standard magnetic sensor chip are V1', V2' and V3' respectively;

[0032] In the reference temperature T1, the low temperature point temperature T2 and the high temperature point temperature T3, the magnetic field difference values of the full magnetic field and the zero magnetic field generated by the magnetic field generating module are ΔB1, ΔB2 and ΔB3 respectively, and there are:

[0033] ;

[0034] ;

[0035] ;

[0036] In the reference temperature T1, the low temperature point temperature T2 and the high temperature point temperature T3, the sensitivities K1, K2 and K3 of the to-be-tested magnetic sensor chip are represented as:

[0037] ;

[0038] ;

[0039] ;

[0040] In the temperature interval from the low temperature point temperature T2 to the reference temperature T1, the sensitivity temperature drift coefficient of the to-be-tested magnetic sensor chip is:

[0041] ;

[0042] The temperature drift coefficient of the magnetic sensor chip under test within the temperature range from the reference temperature T1 to the high temperature T3 is:

[0043] .

[0044] This invention uses a permanent magnet holder and multiple permanent magnets within the holder to form a magnetic field generating module. The permanent magnet holder has through holes that can accommodate the magnetic sensing chip under test and a standard magnetic sensing chip. By reasonably configuring the number and spacing of the permanent magnets, a high-intensity magnetic field with a wide range of variation can be generated in the magnetic field sensitive area of ​​the magnetic sensing chip. The magnetic field strength generated by the low-temperature drift permanent magnet is not affected by the high temperature in the temperature chamber, and the duration of high-temperature testing is not limited. This allows for a large range of sensitivity temperature drift testing of the magnetic sensing chip.

[0045] Furthermore, the present invention has a small size of multiple magnetic field generating modules composed of permanent magnet holders and permanent magnets, which can generate high-intensity magnetic fields in a small space; the combination of multiple magnetic field generating modules with a multi-channel signal acquisition module can simultaneously perform sensitivity temperature drift tests on multiple magnetic sensing chips, thus improving testing efficiency.

[0046] 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

[0047] 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:

[0048] Figure 1 This is a block diagram of the magnetic sensor chip sensitivity temperature drift testing device provided in an embodiment of the present invention;

[0049] Figure 2 This is a top view of the structure of the temperature drift test module of the magnetic sensor chip sensitivity temperature drift test device provided in an embodiment of the present invention.

[0050] Figure 3 This is a side view of the structure of the temperature drift test module of the magnetic sensor chip sensitivity temperature drift test device provided in an embodiment of the present invention.

[0051] Figure 4 This is a flowchart of the sensitivity temperature drift test method for magnetic sensing chips provided in an embodiment of the present invention.

[0052] Explanation of reference numerals in the attached figures

[0053] 1-Insulation chamber, 2-Temperature drift test module, 3-Signal acquisition module, 4-Host computer, 5-Power supply

[0054] 6-Power interface, 7-Signal interface, 8-Magnetic field generating module, 9-Permanent magnet slot, 10-Permanent magnet.

[0055] 11-Permanent magnet holder, 12-Through hole, 13-Chip base, 14-Magnetic sensor chip under test,

[0056] 15-Circuit board, 16-First stud, 17-Second stud, 18-Support plate

[0057] 19 - Standard magnetic sensing chip. Detailed Implementation

[0058] 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.

[0059] 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. 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.

[0060] In this invention, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0061] As described in the background section, existing sensitivity temperature drift testing devices are limited by the internal space of the temperature chamber, restricting the coil size. Furthermore, heat accumulation during high-temperature testing limits the coil current. These limitations in coil size and current restrict the magnetic field strength generated by the coil during high-temperature testing, limiting the effective duration of the test. Consequently, it becomes impossible to directly test the sensitivity temperature drift of a magnetic sensor chip over a large range. Instead, the large-range sensitivity temperature drift characteristics can only be indirectly inferred from the results of relatively small-range sensitivity temperature drift tests. However, the temperature drift characteristics under large and small ranges are not necessarily identical, leading to inaccuracies in this indirect inference method.

[0062] To address the aforementioned problems, this invention provides a magnetic sensor chip sensitivity temperature drift testing device, comprising: a temperature chamber, a temperature drift testing module, and a signal acquisition module. The temperature inside the temperature chamber is adjustable. The temperature drift testing module is housed within the temperature chamber, and the signal acquisition module is connected to the temperature drift testing module. The temperature drift testing module includes m (m≥1) magnetic field generating modules. Each magnetic field generating module includes a permanent magnet holder and multiple permanent magnets. The permanent magnet holder has through holes for accommodating the magnetic sensor chip under test and a standard magnetic sensor chip. The multiple permanent magnets are placed within the permanent magnet holders on both sides of the through holes. The signal acquisition module has m acquisition channels for simultaneously acquiring the output signals of the magnetic sensor chip under test and the standard magnetic sensor chip corresponding to the m magnetic field generating modules.

[0063] This invention utilizes a permanent magnet holder and multiple permanent magnets within it to form a magnetic field generating module. The permanent magnet holder has through-holes capable of accommodating both the magnetic sensing chip under test and a standard magnetic sensing chip. By rationally configuring the number and spacing of the permanent magnets, a high-intensity magnetic field with a wide range of variations can be generated in the magnetic field sensitive area of ​​the magnetic sensing chip. The magnetic field strength generated by the low-temperature drift permanent magnets is unaffected by the high temperature within the temperature chamber, and the duration of high-temperature testing is unlimited. This allows for large-range sensitivity temperature drift testing of the magnetic sensing chip. The invention's multiple magnetic field generating modules, comprised of a permanent magnet holder and multiple permanent magnets, are small in size, enabling the generation of a high-intensity magnetic field in a small space. Combined with a multi-channel signal acquisition module, multiple magnetic field generating modules can simultaneously perform sensitivity temperature drift testing on multiple magnetic sensing chips, improving testing efficiency.

[0064] Figure 1 This is a block diagram of the magnetic sensor chip sensitivity temperature drift testing device provided in an embodiment of the present invention. Figure 1As shown, the magnetic sensor chip sensitivity temperature drift testing device provided in this embodiment includes: a temperature chamber 1, a temperature drift testing module 2, a signal acquisition module 3, a host computer 4, and a power supply 5. The temperature drift testing module 2 is located in the testing area inside the temperature chamber 1, while the signal acquisition module 3, the host computer 4, and the power supply 5 are located outside the temperature chamber 1. The temperature drift testing module 2 inside the temperature chamber 1 is connected to the signal acquisition module 3 and the power supply 5, respectively. The signal acquisition module 3 is connected to the host computer 4. The host computer 4 is equipped with acquisition software that matches the signal acquisition module 3, and can read the acquisition signals from each channel of the signal acquisition module 3.

[0065] like Figure 2 and Figure 3 As shown, the temperature drift test module 2 includes m magnetic field generating modules 8. Each magnetic field generating module 8 includes a permanent magnet holder 11 and multiple permanent magnets 10. A through hole 12 is provided at the center of the plane of the permanent magnet holder 11, which can accommodate one magnetic sensing chip 14 to be tested and one standard magnetic sensing chip 19. With the through hole 12 as the center, multiple permanent magnet slots 9 are symmetrically arranged on the left and right sides of the permanent magnet holder 11, and multiple permanent magnets 10 are symmetrically placed in the permanent magnet slots 9 on both sides of the through hole 12.

[0066] In this embodiment, the temperature drift test module 2 further includes a circuit board 15, on which multiple chip bases 13 for mounting magnetic sensing chips are provided. The chip bases 13 correspond to the through holes 12 of the permanent magnet holder 11. The magnetic sensing chip 14 under test and the standard magnetic sensing chip 19 are fixed on the chip bases 13, passing through and within the through holes 12 of the permanent magnet holder 11. The circuit board 15 of the temperature drift test module 2 also includes a signal interface 7 and a power interface 6. The signal interface 7 has multiple pins corresponding to multiple channels of the signal acquisition module 3, and the output pins of the chip bases 13 are connected to the pins of the signal interface 7. The power interface 6 is connected to a power supply 5 external to the temperature chamber 1, and the power supply 5 pins of the chip bases 13 are connected to the power interface 6.

[0067] like Figure 2 and Figure 3 As shown, the magnetic field generating module 8 is fixed to the circuit board 15 by the first stud 16. The circuit board 15 is fixed to the support plate 18 inside the temperature chamber 1 by the second stud 17. The chip base 13, power interface 6, and signal interface 7 are fixed to the circuit board 15 by soldering. The power supply 5 pins of each chip base 13 on the circuit board 15 are connected to the corresponding pins of the power interface 6, and the corresponding pins of the power interface 6 are connected to the output terminal of the power supply 5. The output signal pins of each chip base 13 are connected to the corresponding pins of each channel of the signal interface 7, and the corresponding pins of each channel of the signal interface 7 are connected to the corresponding pins of each input channel of the signal acquisition module 3. The magnetic sensing chip 14 under test and the standard magnetic sensing chip 19 are fixed to the chip base 13 by plugging.

[0068] In this embodiment, depending on the number of magnetic sensor chip samples to be tested, the temperature drift test module 2 may include m magnetic sensor chips 14 to be tested, m standard magnetic sensor chips 19, 2m chip bases 13, and m magnetic field generating modules 8. Correspondingly, the signal acquisition module 3 and the signal interface 7 are configured with m channels, which can simultaneously acquire the output signals of the magnetic sensor chips 14 to be tested and the standard magnetic sensor chips 19 corresponding to the m magnetic field generating modules 8.

[0069] In this embodiment, each permanent magnet holder 11 of the magnetic field generating module 8 can accommodate at least one magnetic sensing chip 14 to be tested and one standard magnetic sensing chip 19 within its through-hole 12. The standard magnetic sensing chip 19 is a calibrated and standardized magnetic sensing chip with a sensitivity temperature drift not exceeding 50 ppm / ℃. The type of the standard magnetic sensing chip 19 is the same as that of the magnetic sensing chip 14 to be tested, or the type of the standard magnetic sensing chip 19 is different from that of the magnetic sensing chip 14 to be tested.

[0070] In this embodiment, the permanent magnet 10 is made of a low-temperature-coefficient permanent magnet material, with an absolute temperature coefficient not exceeding 0.05% / ℃, such as Sm2Co17 type samarium cobalt permanent magnet material. The magnetization direction of the permanent magnet 10 is perpendicular to the left and right planes of the permanent magnet holder 11. The connecting line formed by multiple permanent magnets 10 passes through the magnetically sensitive area of ​​the magnetic sensing chip within the through hole 12 of the permanent magnet holder 11. The permanent magnet 10 is circular or square in shape, and the shape of the permanent magnet slot 9 matches the shape of the permanent magnet 10, allowing the permanent magnet 10 to be stably inserted into the permanent magnet slot 9.

[0071] In this embodiment, the line connecting the left and right geometric centers of each permanent magnet passes through the magnetically sensitive areas inside the magnetic sensing chip under test and the standard magnetic sensing chip. By adjusting the number and orientation of the permanent magnets, as well as the spacing between the slots, the direction and magnitude of the magnetic field in the magnetically sensitive areas of both chips can be changed. Therefore, by rationally configuring the number, position, and spacing of the permanent magnets, a wide-range magnetic field can be generated in the magnetically sensitive area of ​​the magnetic sensing chip. Furthermore, by controlling the distance between the magnetic sensing chip and the permanent magnets, a high-intensity magnetic field can be generated in a small space. The temperature stability of the cryogenically drifting permanent magnet material, combined with the calibrated standard magnetic sensing chip, solves the problem of generating a high-intensity magnetic field under high-temperature testing conditions, ensuring that the effective duration of the high-intensity magnetic field test is not affected by high temperatures.

[0072] This invention utilizes cryogenically drifting permanent magnets to generate a magnetic field. The magnitude of the magnetic field is changed by altering the number and position of the permanent magnets. By combining the permanent magnets with a temperature chamber, the sensitivity temperature drift test of linear magnetic sensing chips can be achieved in a low-cost and high-efficiency manner.

[0073] This invention also provides a method for testing the temperature drift of a magnetic sensor chip's sensitivity, based on the aforementioned magnetic sensor chip sensitivity temperature drift testing device. Figure 4 As shown, the method for testing the sensitivity temperature drift of the magnetic sensor chip includes the following steps:

[0074] S401, place an appropriate number of permanent magnets in the permanent magnet holder, so that the area where the magnetic sensing chip under test and the standard magnetic sensing chip are located in the through hole of the permanent magnet holder are in a fully magnetized state; set the target temperature of the temperature chamber as the reference temperature, the low temperature point temperature, and the high temperature point temperature respectively, so that the magnetic sensing chip under test and the standard magnetic sensing chip are in the test environment of the reference temperature, the low temperature point temperature, and the high temperature point temperature, and record the output voltage value of the magnetic sensing chip under test and the output voltage value of the standard magnetic sensing chip corresponding to each acquisition channel of the signal acquisition module;

[0075] S402, remove the permanent magnet from the permanent magnet holder, so that the area where the magnetic sensor chip under test and the standard magnetic sensor chip are located in the through hole of the permanent magnet holder is in a zero magnetic state; set the target temperature of the temperature chamber as the reference temperature, the low temperature point temperature, and the high temperature point temperature respectively, so that the magnetic sensor chip under test and the standard magnetic sensor chip are in the test environment of the reference temperature, the low temperature point temperature, and the high temperature point temperature, and record the output voltage value of the magnetic sensor chip under test and the output voltage value of the standard magnetic sensor chip corresponding to each acquisition channel of the signal acquisition module;

[0076] S403 calculates the sensitivity temperature drift of the magnetic sensor chip under test based on the output voltage values ​​of the magnetic sensor chip under test and the standard magnetic sensor chip in test environments at reference temperature, low temperature point, and high temperature point.

[0077] In one example, the method for testing the sensitivity temperature drift of the magnetic sensing chip specifically includes the following steps:

[0078] (1) According to Figure 1 , Figure 2 and Figure 3 The structure shown completes the connection and setup of the test device. Turn on the power switches of the temperature chamber, signal acquisition module, host computer and power supply.

[0079] (2) Insert the corresponding number of magnetic sensing chips and standard magnetic sensing chips into the chip base according to the number of magnetic sensing chip samples to be tested;

[0080] (3) Determine the number and placement of permanent magnets according to the required magnetic field strength. Place the permanent magnets stably in the permanent magnet slot. At this time, the area where the magnetic sensing chip to be tested and the standard magnetic sensing chip are located is in a fully magnetized state.

[0081] (4) Set the target temperature of the temperature chamber to the reference temperature T1 (e.g., 25°C), start the temperature control button, and wait 10 minutes or longer after the temperature chamber reaches the set temperature to allow the magnetic sensor chip under test to reach thermal equilibrium with the inside of the temperature chamber, ensuring that the actual temperature of the magnetic sensor chip under test reaches the set temperature of the temperature chamber.

[0082] (5) Observe the host computer acquisition software and record the full magnetic field output voltage value U1 of the magnetic sensor chip under test and the full magnetic field output voltage value U1' of the standard magnetic sensor chip corresponding to each acquisition channel of the signal acquisition module.

[0083] (6) Set the target temperature of the temperature chamber to the low temperature point T2 (e.g. -40℃), start the temperature control button, and wait for 10 minutes or longer after the temperature chamber reaches the set temperature to allow the magnetic sensor chip under test to reach thermal equilibrium with the inside of the temperature chamber.

[0084] (7) Observe the host computer acquisition software and record the full magnetic field output voltage value U2 of the magnetic sensor chip under test and the full magnetic field output voltage value U2' of the standard magnetic sensor chip corresponding to each acquisition channel of the signal acquisition module.

[0085] (8) Set the target temperature of the temperature chamber to the high temperature point temperature T3 (e.g., 125℃), start the temperature control button, and wait for 10 minutes or longer after the temperature chamber reaches the set temperature to allow the magnetic sensor chip under test to reach thermal equilibrium with the inside of the temperature chamber.

[0086] (9) Observe the host computer acquisition software and record the full magnetic field output voltage value U3 of the magnetic sensor chip under test and the full magnetic field output voltage value U3' of the standard magnetic sensor chip corresponding to each acquisition channel of the signal acquisition module.

[0087] (10) Set the target temperature of the temperature chamber to 25°C, start the temperature control button, and open the temperature chamber after the temperature chamber reaches the set temperature. Take out all the permanent magnets in the permanent magnet holder. At this time, the area where the magnetic sensor chip to be tested and the standard magnetic sensor chip are located is in a zero magnetic state.

[0088] (11) Similar to the above operation, set the target temperature of the temperature chamber as the reference temperature T1, the low temperature T2, and the high temperature T3 respectively, and record the zero magnetic field output voltage values ​​V1, V2, and V3 of the magnetic sensor chip under test corresponding to each channel of the signal acquisition module when the temperature is the reference temperature T1, the low temperature T2, and the high temperature T3; record the zero magnetic field output voltage values ​​V1', V2', and V3' of the standard magnetic sensor chip corresponding to each channel of the signal acquisition module when the temperature is the reference temperature T1, the low temperature T2, and the high temperature T3.

[0089] (12) Assuming the reference temperature is T1, the low temperature is T2, and the high temperature is T3, the sensitivities of the magnetic sensor chip under test are K1, K2, and K3 in the environments of reference temperature T1, low temperature T2, and high temperature T3, respectively, and the sensitivity of the standard magnetic sensor chip is K'.

[0090] In environments with a reference temperature T1, a low temperature T2, and a high temperature T3, the magnetic field differences between the full magnetic field and the zero magnetic field generated by the magnetic field generating module are ΔB1, ΔB2, and ΔB3, respectively. Therefore:

[0091] ;

[0092] ;

[0093] ;

[0094] In environments with a reference temperature T1, a low temperature T2, and a high temperature T3, the sensitivities K1, K2, and K3 of the magnetic sensor chip under test are expressed as follows:

[0095] ;

[0096] ;

[0097] ;

[0098] Within the temperature range from the low-temperature point T2 to the reference temperature T1 (e.g., -40℃ to 25℃), the sensitivity temperature drift coefficient of the magnetic sensor chip under test is:

[0099] ;

[0100] The temperature drift coefficient of the magnetic sensor chip under test within the temperature range from the reference temperature T1 to the high temperature T3 (e.g., 25℃~125℃) is:

[0101] ;

[0102] Therefore, the sensitivity temperature drift of the magnetic sensor chip under test can be obtained.

[0103] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0104] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0105] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0106] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0107] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. A method for testing temperature drift of sensitivity of a magnetic sensing chip, characterized in that, The method is based on a magnetic sensor chip sensitivity temperature drift test device, the device comprises a temperature box, a temperature drift test module and a signal acquisition module, the temperature in the temperature box is adjustable, the temperature drift test module is arranged in the temperature box, and the signal acquisition module is connected with the temperature drift test module; the temperature drift test module comprises m magnetic field generating modules, each magnetic field generating module comprises a permanent magnet holder and a plurality of permanent magnets, the permanent magnet holder is provided with a through hole for accommodating the to-be-tested magnetic sensor chip and the standard magnetic sensor chip, and the plurality of permanent magnets are arranged in the permanent magnet holder on both sides of the through hole; the signal acquisition module has m channels for simultaneously collecting the output signals of the to-be-tested magnetic sensor chip and the standard magnetic sensor chip corresponding to the m magnetic field generating modules, wherein m is a positive integer greater than or equal to 1. The method comprises: a reasonable number of permanent magnets are arranged in the permanent magnet holder, so that the region of the to-be-tested magnetic sensor chip and the standard magnetic sensor chip in the through hole of the permanent magnet holder is in a full magnetic state; the target temperature of the temperature box is set to be a reference temperature, a low temperature point temperature and a high temperature point temperature respectively, so that the to-be-tested magnetic sensor chip and the standard magnetic sensor chip are in a test environment of the reference temperature, the low temperature point temperature and the high temperature point temperature, and the output voltage values of the to-be-tested magnetic sensor chip and the standard magnetic sensor chip corresponding to each acquisition channel of the signal acquisition module are recorded; the permanent magnets in the permanent magnet holder are taken out, so that the region of the to-be-tested magnetic sensor chip and the standard magnetic sensor chip in the through hole of the permanent magnet holder is in a zero magnetic state; the target temperature of the temperature box is set to be a reference temperature, a low temperature point temperature and a high temperature point temperature respectively, so that the to-be-tested magnetic sensor chip and the standard magnetic sensor chip are in a test environment of the reference temperature, the low temperature point temperature and the high temperature point temperature, and the output voltage values of the to-be-tested magnetic sensor chip and the standard magnetic sensor chip corresponding to each acquisition channel of the signal acquisition module are recorded; the magnetic field difference value of the full magnetic field and the zero magnetic field is determined according to the output voltage value of the standard magnetic sensor chip in the full magnetic state, the output voltage value of the standard magnetic sensor chip in the zero magnetic state and the sensitivity of the standard magnetic sensor chip, the sensitivity of the to-be-tested magnetic sensor chip is calculated according to the output voltage value of the to-be-tested magnetic sensor chip in the full magnetic state, the output voltage value of the to-be-tested magnetic sensor chip in the zero magnetic state and the magnetic field difference value of the full magnetic field and the zero magnetic field, and the sensitivity temperature drift coefficient of the to-be-tested magnetic sensor chip is calculated according to the sensitivity of the to-be-tested magnetic sensor chip in the test environment of the reference temperature, the low temperature point temperature and the high temperature point temperature.

2. The magnetic sensing chip sensitivity temperature drift test method according to claim 1, characterized in that, The target temperature of the temperature box is set to be a reference temperature, a low temperature point temperature and a high temperature point temperature respectively, so that the to-be-tested magnetic sensor chip and the standard magnetic sensor chip are in a test environment of the reference temperature, the low temperature point temperature and the high temperature point temperature, and the output voltage values of the to-be-tested magnetic sensor chip and the standard magnetic sensor chip corresponding to each acquisition channel of the signal acquisition module are recorded. After the target temperature of the temperature box is set to be a reference temperature, a low temperature point temperature or a high temperature point temperature, at least 10 minutes are waited after the temperature box reaches the set temperature, so that the to-be-tested magnetic sensor chip and the standard magnetic sensor chip reach a thermal equilibrium state with the inside of the temperature box.

3. The magnetic sensing chip sensitivity temperature drift test method according to claim 1, characterized in that, The sensitivity temperature drift of the to-be-tested magnetic sensor chip is calculated according to the output voltage values of the to-be-tested magnetic sensor chip and the standard magnetic sensor chip in the test environment of the reference temperature, the low temperature point temperature and the high temperature point temperature, and the sensitivity temperature drift coefficient of the to-be-tested magnetic sensor chip is calculated according to the sensitivity of the to-be-tested magnetic sensor chip in the test environment of the reference temperature, the low temperature point temperature and the high temperature point temperature. Let the reference temperature be T1, the low temperature point temperature be T2, and the high temperature point temperature be T3. The sensitivities of the to-be-tested magnetic sensor chip in the reference temperature T1, the low temperature point temperature T2, and the high temperature point temperature T3 environments are K1, K2, and K3, respectively. The sensitivity of the standard magnetic sensor chip is K'; When the magnetic field is full, the output voltage values of the to-be-tested magnetic sensor chip in the reference temperature T1, the low temperature point temperature T2, and the high temperature point temperature T3 environments are U1, U2, and U3, respectively. The output voltage values of the standard magnetic sensor chip are U1', U2', and U3', respectively. When the magnetic field is zero, the output voltage values of the to-be-tested magnetic sensor chip in the reference temperature T1, the low temperature point temperature T2, and the high temperature point temperature T3 environments are V1, V2, and V3, respectively. The output voltage values of the standard magnetic sensor chip are V1', V2', and V3', respectively. In the reference temperature T1, the low temperature point temperature T2, and the high temperature point temperature T3 environments, the magnetic field difference values of the full magnetic field and the zero magnetic field generated by the magnetic field generation module are ΔB1, ΔB2, and ΔB3, respectively. Therefore, ΔB1 = K1·U1 - K'·U1', ΔB2 = K2·U2 - K'·U2', and ΔB3 = K3·U3 - K'·U3'. ； ； ； In the reference temperature T1, the low temperature point temperature T2, and the high temperature point temperature T3 environments, the sensitivities K1, K2, and K3 of the to-be-tested magnetic sensor chip are represented as follows: ； ； ； In the temperature interval from the low temperature point temperature T2 to the reference temperature T1, the sensitivity temperature drift coefficient of the to-be-tested magnetic sensor chip is: ； In the temperature interval from the reference temperature T1 to the high temperature point temperature T3, the sensitivity temperature drift coefficient of the to-be-tested magnetic sensor chip is: 。 4. The magnetic sensing chip sensitivity temperature drift test method according to claim 1, characterized in that, The through hole of the permanent magnet holder of each magnetic field generation module can accommodate at least one to-be-tested magnetic sensor chip and one standard magnetic sensor chip. The standard magnetic sensor chip is a calibrated and calibrated magnetic sensor chip.

5. The magnetic sensing chip sensitivity temperature drift test method according to claim 4, characterized in that, The wires of the plurality of permanent magnets pass through the magnetic sensitive area of the magnetic sensor chip in the through hole of the permanent magnet holder.

6. The magnetic sensing chip sensitivity temperature drift test method according to claim 4, characterized in that, The magnetization direction of the permanent magnet is perpendicular to the plane of the permanent magnet holder.

7. The magnetic sensing chip sensitivity temperature drift test method according to claim 4, characterized in that, The permanent magnet holder is provided with a plurality of permanent magnet slots, and a plurality of permanent magnets are arranged in the plurality of permanent magnet slots.

8. The magnetic sensing chip sensitivity temperature drift test method according to claim 7, characterized in that, The shape of the permanent magnet is circular or square, and the shape of the permanent magnet slot matches the shape of the permanent magnet.

9. The magnetic sensing chip sensitivity temperature drift test method according to claim 1, characterized in that, The material of the permanent magnet is a low-temperature-coefficient permanent magnetic material, and the absolute value of the temperature coefficient of the material of the permanent magnet is not more than 0.05% / °C.

10. The magnetic sensing chip sensitivity temperature drift test method according to claim 1, characterized in that, The temperature drift test module further comprises a circuit board. A plurality of chip bases for mounting magnetic sensor chips are arranged on the circuit board. The through hole of the permanent magnet holder corresponds to the chip base, so that the magnetic sensor chip on the chip base is in the through hole.

11. The magnetic sensing chip sensitivity temperature drift test method according to claim 10, characterized in that, A signal interface is arranged on the circuit board. The signal interface has a plurality of pins corresponding to a plurality of channels of the signal acquisition module, and the output pin of the chip base is connected with the pin of the signal interface.

12. The magnetic sensing chip sensitivity temperature drift test method of claim 10, wherein, A power supply interface is arranged on the circuit board, and the power supply interface is connected with the power supply outside the temperature box. The power supply pin of the chip base is connected with the power supply interface.

13. The magnetic sensing chip sensitivity temperature drift test method of claim 10, wherein, The magnetic field generation module is fixed on the circuit board by a first screw column.

14. The magnetic sensing chip sensitivity temperature drift test method of claim 10, wherein, The circuit board is fixed on the support plate in the temperature box by a second screw column.

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