Thin crystal ingot resistivity detection method based on eddy current method probe

Abstract

The invention discloses a thin crystal ingot resistivity detection method based on an eddy current method probe, which relates to the technical field of semiconductor measurement, solves the problem that the measurement of the corresponding resistivity of a thin crystal ingot to be detected has deviation under partial circumstances, and comprises the following steps: performing electrical detection on the thin crystal ingot to be detected, and analyzing to obtain the calculated surface resistivity of the thin crystal ingot to be detected; based on the calculated surface resistivity of the to-be-measured thin crystal ingot, the thin crystal ingot type of the to-be-measured thin crystal ingot is identified, and the skin depth of the to-be-measured thin crystal ingot is calculated in combination with the skin effect; setting a plurality of groups of contrast thin crystal ingots similar to the thin crystal ingot to be tested, testing the plurality of groups of contrast thin crystal ingots by an eddy current method, and calculating compensation coefficients of the contrast thin crystal ingots based on test results; and calculating a fitting equation based on the compensation coefficient, writing the fitting equation into an upper computer, and calculating the actual resistivity of the to-be-measured thin crystal ingot in combination with the fitting equation, so that accurate measurement of the corresponding resistivity of the to-be-measured thin crystal ingot is realized, and automatic and intelligent measurement of the corresponding resistivity of the to-be-measured thin crystal ingot is also realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor testing, and particularly relates to a thin ingot resistivity detection method based on an eddy current method probe. BACKGROUND

[0002] The thin ingot is a sheet-shaped crystal material in the semiconductor, photovoltaic or special metal industry, has high purity, single crystal or polycrystalline structure, and is a key basic material for manufacturing chips, solar cells and other devices; the eddy current method is a method for detecting electromagnetic induction between electromagnetic fields and metals, and is one of basic methods for nondestructive testing of metal materials; electromagnetic induction is sensitive to many test parameters, so the eddy current detection method is a multi-purpose detection method, but the measurement data are also affected by various interference factors, so the detection result can be accurate and reliable only under the condition of fully utilizing useful information and more effectively suppressing interference information.

[0003] However, when the actual thickness of the thin ingot is smaller than the penetration depth, the traditional method for measuring the thin ingot with the same resistivity and different thicknesses will obtain completely different eddy current signals, and the measured resistivity obtained by inverse solution is also quite different, so the accuracy of the resistivity measurement cannot be guaranteed. Therefore, the application provides a thin ingot resistivity detection method based on an eddy current method probe. SUMMARY

[0004] The application aims to provide a thin ingot resistivity detection method based on an eddy current method probe to solve the problems in the background.

[0005] To achieve the above-mentioned purpose, the application adopts the following technical scheme: A thin ingot resistivity detection method based on an eddy current method probe, the method comprising: Step S1, electrically detecting the thin ingot to be measured to analyze the calculated surface resistivity of the thin ingot to be measured; Step S2, identifying the thin ingot type of the thin ingot to be measured based on the calculated surface resistivity of the thin ingot to be measured, and calculating the skin depth of the thin ingot to be measured in combination with the skin effect; Step S3, setting a plurality of control thin ingots similar to the thin ingot to be measured, testing the plurality of control thin ingots by the eddy current method, and calculating the compensation coefficient of the control thin ingots based on the test results; Step S4, calculating a fitting equation based on the compensation coefficient and writing the fitting equation into an upper computer, and calculating the actual resistivity of the thin ingot to be measured in combination with the fitting equation.

[0006] Further, the step S1 comprises the following sub-steps: Step S11, measuring the thin ingot thickness HD and the thin ingot surface area of the thin ingot to be measured; Step S12, the thin crystal ingot surface area is compared with the thin crystal ingot surface area threshold value, if the thin crystal ingot surface area is less than or equal to the thin crystal ingot surface area threshold value, then on the surface of the measured thin crystal ingot, an optional fixed line segment is set, and the first detection point, the second detection point, the third detection point and the fourth detection point are set on the line segment, and step S14 is executed; Step S13, if the thin crystal ingot surface area is greater than the thin crystal ingot surface area threshold value, then four detection points are set on the upper surface of the measured thin crystal ingot, and are labeled as the first detection point, the second detection point, the third detection point and the fourth detection point in clockwise order; Step S14, current probes are applied on the first detection point and the fourth detection point, and voltage probes are applied on the second detection point and the third detection point, a constant current I is input between the two current probes, and a constant voltage U is input between the two voltage probes.

[0007] Further, the step S1 further includes the following substeps: Step S15, the real-time current value between the two current probes is identified by an ammeter, and the real-time voltage value between the two voltage probes is identified by a real-time voltmeter; Step S16, the surface resistivity DZL corresponding to the measured thin crystal ingot is calculated by a formula, and the formula is as follows: DZL=U / I×HD×XZ;Wherein, XZ is a correction factor; Step S17, the constant current input between the two current probes is changed, the constant voltage input between the two voltage probes is changed, steps S15-S16 are repeated multiple times, and multiple groups of surface resistivity corresponding to the measured thin crystal ingot are calculated; Step S18, the surface resistivity corresponding to the measured thin crystal ingot is added and averaged to obtain the calculated surface resistivity JDZ of the measured wave classic.

[0008] Further, if the thin crystal ingot thickness of the measured thin crystal ingot is less than ten times the probe spacing, the calculation formula of XZ is: ; If the thin crystal ingot thickness of the measured thin crystal ingot is greater than or equal to ten times the probe spacing, XZ is equal to 1.

[0009] Further, the step S2 includes the following substeps: Step S21, the calculated surface resistivity of the measured thin crystal ingot is obtained, the calculated surface resistivity is matched with a known database, and the thin crystal ingot type of the measured thin crystal ingot is identified; Step S22, based on the thin crystal ingot type, the corresponding thin crystal ingot conductivity DD and thin crystal ingot magnetic conductivity CD are identified in combination with the Internet of Things; In step S23, a probe parameter corresponding to the eddy current probe used in the eddy current detection method is set; wherein the probe parameter includes a probe type of the eddy current probe and a coil structure of the excitation coil bound to the eddy current probe; In step S24, alternating current is supplied to the excitation coil bound to the eddy current probe, and an excitation frequency PL of the excitation coil is identified; wherein the excitation frequency of the excitation coil is consistent with the frequency of the alternating current supplied to the excitation coil; In step S25, the concept of skin effect is introduced, and the skin depth QS of the eddy current probe corresponding to the measured thin ingot is calculated based on a calculation formula of the skin effect, and the calculation formula is specifically as follows: .

[0010] Further, the step S3 includes the following sub-steps: In step S31, the skin depth of the measured thin ingot is obtained, and three times of the skin depth is taken as the penetration depth of the measured thin ingot; In step S32, the calculated surface resistivity of the measured thin ingot and the surface area of the thin ingot are obtained, and the calculated surface resistivity and the surface area of the thin ingot are taken as the parameters of the control thin ingot; In step S33, the penetration depth is taken as the peak thickness of the control thin ingot, so that different control thin ingots have a ladder-like thickness change, and the control thin ingots are numbered as i, i = 1, 2, …, z, z is a positive integer.

[0011] Further, the step S3 further includes the following sub-steps: In step S34, the control thin ingot with the smallest thickness is selected, the upper surface of the control thin ingot is taken as a detection surface, the edge of the detection surface is identified, the area with a fixed width from the edge to the center of the detection surface is taken as a dangerous area, the area other than the dangerous area is taken as a normal area, the normal area is divided into a plurality of grids with fixed side length, and n grids are randomly selected in the plurality of grids as detection grids; In step S35, the eddy current probe with the parameters in steps S23-S24 is used to measure the eddy current signals of the detection grids in sequence; the calculated resistivity of the control thin ingot is obtained based on the back analysis of the eddy current signals, and the detection resistivities corresponding to the n detection grids are added and averaged to obtain a detection resistivity.

[0012] Further, the step S3 further includes the following sub-steps: In step S36, the detection resistivity of the control thin ingot is compared with the calculated surface resistivity, if the detection resistivity of the control thin ingot is equal to the calculated surface resistivity, step S37 is directly executed; if the detection resistivity of the control thin ingot is not equal to the calculated surface resistivity, the thickness and the detection resistivity of the control thin ingot are recorded; Step S37, selecting the next control thin ingot of the next thickness, repeating the steps S34 to S36, and replacing the process of dividing the grid with selecting the detection grid directly in the same position of the current control thin ingot; finally obtaining a plurality of groups of detection resistivity and thin ingot thickness; Step S38, obtaining the compensation coefficient of the control thin ingot corresponding to the thin ingot thickness by dividing the detection resistivity of the control thin ingot by the calculated surface resistivity.

[0013] Further, the inverse process of calculating the resistivity is specifically as follows: Step S351, constructing the expression ZK of the eddy current signal according to the definition of the eddy current signal; Wherein, the essence of eddy current detection is to induce eddy current in the thin ingot by alternating magnetic field, the resistivity of the thin ingot will affect the distribution and strength of the eddy current, and then affect the impedance change detected by the eddy current probe, therefore, the impedance sensed by the eddy current probe is represented as: ZK=S+X×j;wherein, ZK is a complex number, S represents the real part, X represents the imaginary part, and j is a constant; Step S352, when the eddy current probe is close to the control thin ingot, the impedance sensed by the eddy current probe is represented as: ; in the formula, k is a constant, π is a constant, and JD is a calculated resistivity; Step S353, obtaining the expression of the calculated resistivity JD by combining the two impedance equations, substituting to obtain the calculated resistivity, and the expression of the calculated resistivity is specifically as follows: ; in the formula, |ZK| is the modulus of the impedance, .

[0014] Further, the step S4 comprises the following sub-steps: Step S41, obtaining the compensation coefficient and the thin ingot thickness of the control thin ingot; Step S42, constructing the relationship trend graph between the independent variable and the dependent variable by taking the thin ingot thickness as the independent variable and the compensation coefficient as the dependent variable, and obtaining the corresponding fitting equation by combining the function fitting algorithm; Step S43, measuring the thin ingot thickness of the to-be-measured thin ingot, inputting the thin ingot thickness into the upper computer, and detecting the to-be-measured thin ingot by the eddy current probe; comparing the thin ingot thickness with the penetration depth, if the thin ingot thickness is greater than or equal to the penetration depth, the detection resistivity of the to-be-measured thin ingot is directly outputted; Step S44, if the thin ingot thickness is less than the penetration depth, the detection resistivity of the to-be-measured thin ingot is sent to the upper computer, and the detection resistivity is outputted after being processed by the fitting equation.

[0015] As described above, by adopting the above technical scheme, the present application has the following beneficial effects: 1. The present invention performs electrical testing on a thin crystal ingot to be tested, analyzes and obtains a calculated surface resistivity of the thin crystal ingot to be tested; identifies the type of the thin crystal ingot to be tested based on the calculated surface resistivity of the thin crystal ingot to be tested, and calculates the skin depth of the thin crystal ingot to be tested in combination with the skin effect; thereby confirming the corresponding skin depth of the thin crystal ingot to be tested; 2. The present invention sets multiple groups of control thin crystal ingots similar to the thin crystal ingot to be tested, performs eddy current testing on the multiple groups of control thin crystal ingots, calculates the compensation coefficients of the control thin crystal ingots based on the test results, and then completes the calculation of all preconditions of the fitting equation; 3. The present invention calculates the fitting equation based on the compensation coefficient and writes it into the host computer, and calculates the actual resistivity of the thin crystal ingot to be measured in combination with the fitting equation. While ensuring the accuracy of the measurement results, the present invention also realizes automated and intelligent measurement of the resistivity of the thin crystal ingot to be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0017] Figure 1 is a flow chart of the overall method of the present invention; Figure 2 It is a flow chart of the algorithm for fitting the equation in the present invention; Figure 3 A flow chart for realizing compensation in the present invention; Figure 4 A trend diagram showing the relationship between the independent variable and the dependent variable corresponding to the fitting function in the present invention; Figure 5 It is a structural diagram of the computer device in the present invention. DETAILED DESCRIPTION

[0018] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] Example 1: Please refer to Figures 1-4 As shown, the technical solution provided by the present invention is: a thin crystal ingot resistivity detection method based on an eddy current probe, wherein the surface resistivity of the thin crystal ingot to be measured is obtained by performing electrical detection on the thin crystal ingot to be measured, the skin depth of the thin crystal ingot to be measured is calculated by the skin equation, a plurality of reference thin crystal ingots are set in combination with the size of the thin crystal ingot to be measured and the skin depth, a fitting equation is constructed by analyzing the detected resistivity of the reference thin crystal ingots, and intelligent and automated accurate measurement of the thin crystal ingot to be measured is achieved based on the fitting equation; In the present application, the thin ingot resistivity detection method is specifically as follows: Step S1, electrically detecting the thin ingot to be measured, and analyzing to obtain the calculated surface resistivity of the thin ingot to be measured; In the present application, the step S1 comprises the following sub-steps: Step S11, measuring the thin ingot thickness HD and the thin ingot surface area of the thin ingot to be measured; Step S12, comparing the thin ingot surface area with the thin ingot surface area threshold value, if the thin ingot surface area is less than or equal to the thin ingot surface area threshold value, then selecting a fixed line segment on the surface of the thin ingot to be measured, setting the first detection point, the second detection point, the third detection point and the fourth detection point on the line segment and executing step S14; Step S13, if the thin ingot surface area is greater than the thin ingot surface area threshold value, then setting four detection points on the four ends of the upper surface of the thin ingot to be measured, and sequentially labeling them as the first detection point, the second detection point, the third detection point and the fourth detection point in a clockwise order; Step S14, applying current probes on the first detection point and the fourth detection point, and applying voltage probes on the second detection point and the third detection point, and inputting a constant current I between the two current probes and a constant voltage U between the two voltage probes; It should be additionally noted that the constant voltage U and the constant current I, the pressure between the current probes and the voltage probes and the thin ingot to be measured is controlled between one newton and five newtons, thereby avoiding damaging the thin ingot to be measured or introducing contact resistance; Step S15, identifying the real-time current value between the two current probes by the ammeter, and identifying the real-time voltage value between the two voltage probes by the real-time voltmeter; Step S16, calculating the surface resistivity DZL corresponding to the thin ingot to be measured by the formula, which is specifically as follows: DZL=U / I×HD×XZ;wherein XZ is a correction factor, the value of which is related to the probe distance JJ and the size of the thin ingot to be measured, and specifically: If the thin ingot thickness of the thin ingot to be measured is less than ten times the probe distance, then the calculation formula of XZ is: ; If the thin ingot thickness of the thin ingot to be measured is greater than or equal to ten times the probe distance, then XZ is regarded as 1; Step S17, changing the constant current input between the two current probes and the constant voltage input between the two voltage probes, repeating steps S15-S16 multiple times, and calculating to obtain multiple groups of surface resistivity corresponding to the thin ingot to be measured; Step S18, adding and averaging the multiple groups of surface resistivity corresponding to the thin ingot to be measured to obtain the calculated surface resistivity JDZ of the thin ingot to be measured.

[0020] Step S2, identifying the type of the thin crystal ingot to be tested based on the calculated surface resistivity of the thin crystal ingot to be tested, and calculating the skin depth of the thin crystal ingot to be tested in combination with the skin effect; In the present invention, step S2 includes the following sub-steps: Step S21, obtaining the calculated surface resistivity of the thin crystal ingot to be tested, matching the calculated surface resistivity with a known database, and identifying the type of the thin crystal ingot to be tested; specifically, the types of thin crystal ingots include semiconductor materials such as single crystal silicon and silicon carbide; Step S22, identifying the corresponding thin crystal ingot electrical conductivity DD and thin crystal ingot magnetic permeability CD based on the type of the thin crystal ingot and in combination with the Internet of Things; Step S23, setting probe parameters corresponding to the eddy current probe used in the eddy current testing method; wherein the probe parameters include the probe type of the eddy current probe and the coil structure of the excitation coil bound to the eddy current probe; Specifically, the probe type of the eddy current probe in the present invention is preferably a differential eddy current probe, and the coil structure of the excitation coil is preferably a double-coil structure, which can improve sensitivity and anti-interference ability compared to traditional probe types and coil structures. In practice, the coil diameter can be set to 2 mm, the spacing between the double coils is set to 1 mm, and the distance between the eddy current probe and the thin crystal ingot to be measured is set to 0.1 mm. Step S24: supplying alternating current to the excitation coil bound to the eddy current probe, and identifying the excitation frequency PL of the excitation coil; wherein the excitation frequency of the excitation coil is consistent with the frequency of the alternating current supplied to the excitation coil; Step S25, where the concept of skin effect is introduced, the skin depth QS of the eddy current probe corresponding to the thin crystal ingot to be measured is calculated based on the calculation formula of the skin effect. The calculation formula is as follows: ; Specifically, the skin effect is the penetration depth of an alternating electromagnetic field in a conductor when it decays to 1 / e (about 37%) of its surface value.

[0021] Step S3, setting a plurality of control thin crystal ingots similar to the thin crystal ingot to be tested, performing eddy current tests on the plurality of control thin crystal ingots, and calculating compensation coefficients of the control thin crystal ingots based on the test results; In the present invention, step S3 includes the following sub-steps: Step S31, obtaining the skin depth of the thin crystal ingot to be tested, and recording three times the skin depth as the penetration depth of the thin crystal ingot to be tested; it should be noted that, for the thin crystal ingot to be tested, at the skin depth, the eddy current density of the thin crystal ingot to be tested is 37% of the surface value, and at three times the skin depth, the eddy current density of the thin crystal ingot to be tested is 5% of the surface value; Step S32, the calculated surface resistivity of the to-be-tested thin ingot and the surface area of the thin ingot are obtained, and the calculated surface resistivity and the surface area of the thin ingot are taken as the parameters of the control thin ingot; in the present application, the upper surfaces of all the control thin ingots are regarded as being consistent in shape; Step S33, the peak thickness of the control thin ingot is taken as the penetration depth, so that different control thin ingots have stepped thickness changes, the control thin ingots are numbered as i, i = 1, 2, …, z, z is a positive integer; For example, the thickness distribution of the control thin ingot can be: 0.5 mm, 1 mm, 1.5 mm, …, 8.5 mm, 9 mm; It should be additionally explained that when the thickness of the to-be-tested thin ingot is greater than the penetration depth, the eddy current is mainly distributed in the surface layer close to the excitation coil, and the material state in the sample has little effect on the eddy current signal, so for such a thick to-be-tested thin ingot, as long as the surface performance is consistent, the detection result will be very accurate; When the thickness of the thin ingot is less than the penetration depth, the eddy current cannot be limited to the surface layer, and even penetrates the entire thickness or forms a unique circulating path in a limited range, which will affect the inductive impedance of the coil, even if the surface area resistivity is the same, the change of the inductive magnetic field is different, which depends not only on the resistivity of the surface layer, but also on the relationship between the thickness of the to-be-tested thin ingot and the test depth of the probe, therefore, the to-be-tested thin ingots with the same resistivity but different thicknesses will give completely different eddy current signals, and the present application is mainly aimed at solving this situation; Step S34, the control thin ingot with the smallest thickness is selected, the upper surface of the control thin ingot is taken as the detection surface, the edge of the detection surface is identified, the area with a fixed width from the edge to the center of the detection surface is recorded as a dangerous area, the area other than the dangerous area is recorded as a normal area, the normal area is divided into a plurality of grids with fixed side length, and n grids are randomly selected from the plurality of grids as detection grids; specifically, the fixed width is preferably 10 mm, the side length of the grid is preferably 1 mm, and n is preferably 3; Step S35, the eddy current signals of the detection grids are measured in sequence by the eddy current probe with the parameters described in steps S23-S24; the calculated resistivity of the control thin ingot is obtained based on the eddy current signal, and the detection resistivities corresponding to the n detection grids are added and averaged to obtain the detection resistivity; The inverse solution process of the calculated resistivity in the present application is as follows: Step S351, an expression ZK of the eddy current signal is constructed according to the definition of the eddy current signal; Wherein, the essence of the eddy current detection is to induce eddy current in the thin ingot through alternating magnetic field, the resistivity of the thin ingot will affect the distribution and intensity of the eddy current, and further affect the change of the impedance detected by the eddy current probe, therefore, the impedance sensed by the eddy current probe is expressed as: ZK=S+Xj; wherein, ZK is a complex number, S represents a real part, X represents an imaginary part, and j is a constant; Step S352, when the eddy current probe is close to the control thin ingot, the impedance sensed by the eddy current probe is represented as: ; in the formula, k is a constant, specifically related to the eddy current probe and the coil parameters, π is a constant, and JD is the calculated resistivity (i.e. inverse solution target); Step S353, the two impedance equations are combined to obtain the expression of the calculated resistivity JD, which is substituted into the inverse solution to obtain the calculated resistivity, and the expression of the calculated resistivity is specifically: ; in the formula, |ZK| is the modulus of the impedance, ; Step S36, the detection resistivity of the control thin ingot is compared with the calculated surface resistivity, if the detection resistivity of the control thin ingot is equal to the calculated surface resistivity, step S37 is directly executed; if the detection resistivity of the control thin ingot is not equal to the calculated surface resistivity, the thickness and the detection resistivity of the control thin ingot are recorded; Step S37, the control thin ingot with the next thin ingot thickness is selected, steps S34 to S36 are repeatedly executed, and the process of dividing the grid is replaced by directly selecting the detection grid at the same position in the current control thin ingot; finally, a plurality of groups of detection resistivity and thin ingot thickness are obtained; Step S38, the compensation coefficient of the control thin ingot corresponding to the thin ingot thickness is obtained by dividing the detection resistivity of the control thin ingot by the calculated surface resistivity; Specifically, the relationship between the thin ingot thickness and the compensation coefficient is shown in Table 1: Table 1:

[0022] Step S4, a fitting equation is calculated based on the compensation coefficient and written into the upper computer, and the actual resistivity of the to-be-measured thin ingot is calculated combined with the fitting equation; In the application, step S4 includes the following sub-steps: Step S41, the compensation coefficient of the control thin ingot and the thin ingot thickness are obtained; Step S42, referring to Figure 4 , the relationship trend graph between the independent variable and the dependent variable is constructed by taking the thin ingot thickness as the independent variable (i.e. X-axis) and the compensation coefficient as the dependent variable (i.e. Y-axis), the corresponding fitting equation is obtained combined with the function fitting algorithm, and the fitting equation is written into the upper computer; Step S43, measuring the thickness of the thin crystal ingot to be tested, inputting the thickness of the thin crystal ingot into the host computer, and testing the thin crystal ingot to be tested using an eddy current probe; comparing the thickness of the thin crystal ingot with the penetration depth, and directly outputting the test resistivity of the thin crystal ingot to be tested if the thickness of the thin crystal ingot is greater than or equal to the penetration depth; Step S44: If the thickness of the thin crystal ingot is less than the penetration depth, the detected resistivity of the thin crystal ingot to be tested is sent to the host computer, processed through the fitting equation and then output.

[0023] Example 2: Figure 5 As shown, this embodiment provides a computer device, which may include: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus. The processor may call logic instructions in the memory to execute a thin crystal ingot resistivity testing method based on an eddy current probe, the method comprising: performing electrical testing on the thin crystal ingot to be tested, analyzing and obtaining a calculated surface resistivity of the thin crystal ingot to be tested; identifying the type of the thin crystal ingot to be tested based on the calculated surface resistivity of the thin crystal ingot to be tested, and calculating the skin depth of the thin crystal ingot to be tested in combination with the skin effect; setting multiple groups of control thin crystal ingots similar to the thin crystal ingot to be tested, performing eddy current testing on the multiple groups of control thin crystal ingots, and calculating compensation coefficients for the control thin crystal ingots based on the test results; calculating a fitting equation based on the compensation coefficient, writing the equation into a host computer, and calculating the actual resistivity of the thin crystal ingot to be tested in combination with the fitting equation.

[0024] In addition, the logical instructions in the above-mentioned memory can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present application, or the part that contributes to the existing technology, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program code.

[0025] In another aspect, the present application also provides a computer program product, which comprises a computer program stored on a computer readable storage medium, and the computer program comprises program instructions, when the program instructions are executed by a computer, the computer can execute a thin ingot resistivity detection method based on an eddy current method probe provided by each of the above methods, and the method comprises: performing electrical detection on a to-be-detected thin ingot, and analyzing to obtain a calculated surface resistivity of the to-be-detected thin ingot; identifying a thin ingot type of the to-be-detected thin ingot based on the calculated surface resistivity of the to-be-detected thin ingot, and calculating a skin depth of the to-be-detected thin ingot in combination with a skin effect; setting a plurality of groups of control thin ingots similar to the to-be-detected thin ingot, performing eddy current method testing on the plurality of groups of control thin ingots, and calculating compensation coefficients of the control thin ingots based on testing results; calculating a fitting equation based on the compensation coefficients and writing the fitting equation into an upper computer, and calculating an actual resistivity of the to-be-detected thin ingot in combination with the fitting equation.

[0026] In another aspect, the present application also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement a thin ingot resistivity detection method based on an eddy current method probe provided by each of the above methods, and the method comprises: performing electrical detection on a to-be-detected thin ingot, and analyzing to obtain a calculated surface resistivity of the to-be-detected thin ingot; identifying a thin ingot type of the to-be-detected thin ingot based on the calculated surface resistivity of the to-be-detected thin ingot, and calculating a skin depth of the to-be-detected thin ingot in combination with a skin effect; setting a plurality of groups of control thin ingots similar to the to-be-detected thin ingot, performing eddy current method testing on the plurality of groups of control thin ingots, and calculating compensation coefficients of the control thin ingots based on testing results; calculating a fitting equation based on the compensation coefficients and writing the fitting equation into an upper computer, and calculating an actual resistivity of the to-be-detected thin ingot in combination with the fitting equation.

[0027] The apparatus embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, that is, can be located in one place, or can be distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the present embodiment scheme. Those skilled in the art can understand and implement without creative labor.

[0028] Those skilled in the art can clearly understand the implementation of the various embodiments by means of software and the necessary general hardware platform from the above description of the embodiments, and of course, the embodiments can also be implemented by hardware. Based on such understanding, the above technical solutions, essentially or in other words, the part of the prior art that contributes to the technical solutions can be embodied in the form of a software product. The computer software product can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0029] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A thin ingot resistivity measurement method based on a vortex method probe, characterized by, The method comprises: Step S1, electrically detecting the to-be-detected thin ingot to obtain a calculated surface resistivity of the to-be-detected thin ingot; Step S2, identifying a thin ingot type of the to-be-detected thin ingot based on the calculated surface resistivity of the to-be-detected thin ingot, and calculating a skin depth of the to-be-detected thin ingot in combination with a skin effect; Step S3, setting a plurality of groups of control thin ingots similar to the to-be-detected thin ingot, testing the plurality of groups of control thin ingots by an eddy current method, and calculating compensation coefficients of the control thin ingots based on test results; Step S4, calculating a fitting equation based on the compensation coefficients and writing the fitting equation into an upper computer, and calculating an actual resistivity of the to-be-detected thin ingot in combination with the fitting equation.

2. The method for measuring the resistivity of a thin ingot based on an eddy current probe according to claim 1, characterized in that, The step S1 comprises the following sub-steps: Step S11, measuring a thin ingot thickness HD and a thin ingot surface area of the to-be-detected thin ingot; Step S12, comparing the thin ingot surface area with a thin ingot surface area threshold value, if the thin ingot surface area is less than or equal to the thin ingot surface area threshold value, then setting a first detection point, a second detection point, a third detection point and a fourth detection point on a fixed line segment on a surface of the to-be-detected thin ingot and performing step S14; Step S13, if the thin ingot surface area is greater than the thin ingot surface area threshold value, then setting four detection points on four ends of the upper surface of the to-be-detected thin ingot and sequentially labeling the four detection points as the first detection point, the second detection point, the third detection point and the fourth detection point in a clockwise order; Step S14, applying current probes on the first detection point and the fourth detection point, and applying voltage probes on the second detection point and the third detection point, and inputting a constant current I between the two current probes and a constant voltage U between the two voltage probes.

3. The method of resistivity measurement of thin ingot based on eddy current probe according to claim 2, characterized in that, The step S1 further comprises the following sub-steps: Step S15, identifying a real-time current value between the two current probes by a current meter and identifying a real-time voltage value between the two voltage probes by a real-time voltmeter; Step S16, calculating a surface resistivity DZL corresponding to the to-be-detected thin ingot by a formula, and the formula is specifically as follows: DZL=U / I×HD×XZ; wherein XZ is a correction factor; Step S17, changing the constant current between the two current probes and the constant voltage between the two voltage probes, repeating steps S15-S16 multiple times, and calculating a plurality of groups of surface resistivities corresponding to the to-be-detected thin ingot; Step S18, adding and averaging the plurality of groups of surface resistivities to obtain a calculated surface resistivity JDZ of the to-be-detected thin ingot.

4. The method of resistivity measurement of thin ingot based on eddy current probe according to claim 3, characterized in that, If the thin ingot thickness of the to-be-detected thin ingot is less than ten times a probe spacing, then a calculation formula of XZ is as follows: ； If the thin ingot thickness of the to-be-detected thin ingot is greater than or equal to ten times the probe spacing, then XZ is equal to 1.

5. The method of resistivity measurement of thin ingot based on eddy current probe according to claim 1, characterized in that, The step S2 comprises the following sub-steps: Step S21, obtaining the calculated surface resistivity of the to-be-detected thin ingot, matching the calculated surface resistivity with a known database, and identifying a thin ingot type of the to-be-detected thin ingot; Step S22, identifying a thin ingot conductivity DD and a thin ingot magnetic conductivity CD corresponding to the to-be-detected thin ingot based on the thin ingot type in combination with an Internet of Things. In step S23, a probe parameter corresponding to the eddy current probe used in the eddy current detection method is set; wherein the probe parameter includes a probe type of the eddy current probe and a coil structure of the excitation coil bound to the eddy current probe; In step S24, alternating current is passed to the excitation coil bound to the eddy current probe, and an excitation frequency PL of the excitation coil is identified; wherein the excitation frequency of the excitation coil is consistent with the frequency of the alternating current passed to the excitation coil; In step S25, the skin depth QS of the eddy current probe corresponding to the thin ingot to be measured is calculated based on a calculation formula of the skin effect, and the calculation formula is specifically as follows: 。 6. The method of resistivity measurement of thin ingot based on eddy current probe according to claim 1, characterized in that, The step S3 includes the following sub-steps: In step S31, the skin depth of the thin ingot to be measured is obtained, and three times of the skin depth is taken as the penetration depth of the thin ingot to be measured; In step S32, the calculated surface resistivity of the thin ingot to be measured and the surface area of the thin ingot are obtained, and the calculated surface resistivity and the surface area of the thin ingot are taken as the parameters of the control thin ingot; In step S33, the penetration depth is taken as the peak thickness of the control thin ingot, so that different control thin ingots have a ladder-shaped thickness change, and the control thin ingots are numbered as i, i = 1, 2, …, z, and z is a positive integer.

7. The method of resistivity measurement of thin ingot based on eddy current probe according to claim 6, characterized in that, The step S3 further includes the following sub-steps: In step S34, the control thin ingot with the smallest thickness is selected, the upper surface of the control thin ingot is taken as a detection surface, the edge of the detection surface is identified, a region with a fixed width from the edge to the center of the detection surface is taken as a dangerous region, a region other than the dangerous region is taken as a normal region, the normal region is divided into a plurality of grids with fixed side length, and n grids are randomly selected from the plurality of grids as detection grids; In step S35, the eddy current probe with the parameters in steps S23-S24 is used to measure the eddy current signals of the detection grids in sequence; and the calculated resistivity of the control thin ingot is obtained based on the back solution of the eddy current signals, the detection resistivities corresponding to the n detection grids are added and averaged to obtain a detection resistivity.

8. The method of resistivity measurement of thin ingot based on eddy current probe according to claim 7, characterized in that, The step S3 further includes the following sub-steps: In step S36, the detection resistivity of the control thin ingot is compared with the calculated surface resistivity; If the detection resistivity of the control thin ingot is equal to the calculated surface resistivity, step S37 is directly executed; If the detection resistivity of the control thin ingot is not equal to the calculated surface resistivity, the thickness and the detection resistivity of the control thin ingot are recorded; In step S37, the control thin ingot with the next thin ingot thickness is selected, steps S34-S36 are repeatedly executed, and the process of dividing the grids is replaced by directly selecting the detection grids at the same position in the current control thin ingot; finally, a plurality of groups of detection resistivities and thin ingot thicknesses are obtained; In step S38, the compensation coefficient of the control thin ingot corresponding to the thin ingot thickness is obtained by dividing the detection resistivity of the control thin ingot by the calculated surface resistivity.

9. The method of resistivity measurement of thin ingot based on eddy current probe according to claim 7, characterized in that, The back solution process of the calculated resistivity is specifically as follows: In step S351, an expression ZK of the eddy current signal is constructed according to the definition of the eddy current signal; Wherein, the eddy current detection is to induce eddy current in the thin ingot by alternating magnetic field, the resistivity of the thin ingot affects the distribution and intensity of the eddy current, and further affects the impedance change detected by the eddy current probe, so the impedance sensed by the eddy current probe is expressed as: ZK=S+X×j; wherein, ZK is a complex number, S represents a real part, X represents an imaginary part, and j is a constant; Step S352, when the eddy current probe is close to the control thin crystal ingot, the impedance sensed by the eddy current probe is represented as: ; in the formula, k is a constant, π is a circular constant, and JD is the calculated resistivity; In step S353, two impedance equations are solved to obtain an expression for calculating the resistivity JD, and JD is obtained by substitution, and the expression for calculating the resistivity JD is as follows: ; where |ZK| is the modulus of the impedance, .

10. The method of resistivity measurement of thin ingot based on eddy current probe according to claim 1, characterized in that, The step S4 includes the following sub-steps: Step S41, obtaining the compensation coefficient of the control thin ingot and the thin ingot thickness; Step S42, constructing a relationship trend chart between the independent variable and the dependent variable by taking the thin ingot thickness as the independent variable and the compensation coefficient as the dependent variable, and obtaining the corresponding fitting equation by combining the function fitting algorithm; Step S43, measuring the thin ingot thickness of the to-be-measured thin ingot, inputting the thin ingot thickness into the upper computer, and detecting the to-be-measured thin ingot by the eddy current probe; The thin ingot thickness and the penetration depth are compared, and if the thin ingot thickness is greater than or equal to the penetration depth, the detection resistivity of the to-be-measured thin ingot is directly outputted; Step S44, if the thin ingot thickness is less than the penetration depth, the detection resistivity of the to-be-measured thin ingot is sent to the upper computer, and the detection resistivity of the to-be-measured thin ingot is outputted after processing by the fitting equation.

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