Surface density full-measurement method and system

Abstract

The present invention relates to the technical field of surface density measurement, and in particular to a surface density full-measurement method and system. The method comprises the following steps: (1) measuring a zero point; (2) calibrating a target measurement object; (3) performing actual line scanning measurement; (4) determining the actual size; and (5) performing error correction. The surface density full-measurement system comprises: a ray source, a linear array detector, and a processor; the ray source is fixed relative to the linear array detector; and a sample to be measured is placed between the ray source and the linear array detector and can move relative to the ray source and the linear array detector. When using the ray source and the linear array detector to perform line scanning full-measurement, there is no need to perform point scanning reciprocating motion in the width direction. The stability of the measurement effect is improved while performing full measurement.

Description

A method and system for full surface density inspection Technical Field

[0001] The present invention relates to the technical field of surface density detection, and in particular to a surface density full detection method and system. Background Art

[0002] With the gradual improvement of industrial intelligent manufacturing requirements, the demand for product quality and safety is becoming increasingly stringent. Traditional X / β-ray thickness gauges use a reciprocating motion in the width direction to perform only Z-shaped scanning sampling inspections on electrodes, metal foils, plastic films, paper, metal sheets, etc. In this way, the majority of the areas on the inspection object are undetected. If the surface density / thickness of these areas is unqualified, the traditional thickness gauge cannot detect it and still considers the inspection object to meet the standards, which will have a serious impact on product quality and further pose a huge hidden danger to subsequent production processes or the final product. Therefore, for the production of electrodes, foils, films, etc., which require very high thickness / surface density consistency, full inspection that can obtain the entire thickness / surface density distribution data of the inspection object is a must.

[0003] Summary of the Invention

[0004] The purpose of the present invention is to provide a method and system for full surface density inspection to solve the product quality problem caused by sampling inspection proposed in the above background technology, in which the surface density / thickness of most uninspected areas of the inspection object are unqualified.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for full surface density inspection, comprising the following steps:

[0006] (1) Zero point measurement: The ray source emits rays to a linear array detector, which includes a plurality of pixel detectors, and each pixel detector of the linear array detector detects the primary intensity of the ray passing through the air and reaching the detector;

[0007] (2) Target detection object calibration: a sample of known surface density is placed at the detection object position, and the rays emitted by the ray source penetrate the sample of known surface density and reach the linear array detector. According to the attenuation law of the ray beam, the corresponding relationship between the surface density of the sample of known surface density and the measurement signal is obtained to determine the calibration model;

[0008] (3) Actual line scan measurement: The sample to be tested is placed between the ray source and the linear array detector. The ray source and the linear array detector are relatively fixed. The sample to be tested moves relative to the ray source and the linear array detector. The ray source irradiates the sample to be tested to form a light spot covering its entire width. The rays emitted by the ray source penetrate the sample to be tested and reach the linear array detector. The linear array detector outputs a two-dimensional signal after attenuation. According to the zero point of each pixel detector of the linear array detector and the calibration model, the two-dimensional surface density distribution data of the sample to be tested is obtained;

[0009] (4) determining the actual size: determining the actual size of the single area density data detected by each pixel detector of the linear array detector in the width direction and the tape running direction, and further obtaining the two-dimensional actual size of the sample corresponding to the two-dimensional area density distribution data;

[0010] (5) Error correction: including keeping the relative positions of the ray source and the linear array detector unchanged, moving them out of the detection object's belt zone, measuring the zero point in real time and updating it; keeping the relative positions of the ray source and the linear array detector unchanged, moving them out of the detection object's belt zone, and correcting the detection results by measuring the standard film.

[0011] Furthermore, in step (2), the attenuation law of the ray beam satisfies the following formula: I = I0*e -λm

[0012] Wherein, I0 is the primary intensity of the ray measured in step (1), I is the intensity of the ray passing through the sample with known surface density measured in step (2), λ is the attenuation coefficient of the sample with known surface density per unit surface density for the ray, and m is the surface density;

[0013] Therefore, the calculation formula for the surface density m in step (3) is:

[0014] Furthermore, the area density of each pixel detector of the linear array detector is fitted with the measurement signal by a least squares polynomial, wherein the fitting correlation coefficient R 2 >0.995.

[0015] Furthermore, the actual size of the single area density data detected by each pixel detector in the step (4) in the tape running direction corresponds to: tape running speed / sampling frequency.

[0016] Furthermore, the actual size of the single area density data detected by each pixel detector in step (4) in the width direction is the single pixel spacing size of the linear array detector.

[0017] Furthermore, the actual size of the single area density data detected by each pixel detector in step (4) in the width direction is:

[0018] Wherein, d is the actual size corresponding to the width direction of the sample to be detected, d0 is the single pixel interval size of the linear array detector, f is the magnification ratio, h1 is the distance from the focus of the ray source to the linear array detector, and h2 is the distance from the focus of the ray source to the sample to be detected.

[0019] A surface density full inspection system, comprising:

[0020] A ray source, wherein the ray source is an X / β ray source;

[0021] A linear array detector, comprising a plurality of pixel detectors, configured to receive the radiation emitted by the radiation source and output a two-dimensional signal after attenuation;

[0022] A collimating grid, used for collimating the rays emitted by the ray source, wherein a single interval of the collimating grid corresponds to a single pixel size of the linear array detector;

[0023] A processor is configured to receive the two-dimensional signal output by the linear array detector, and calculate the two-dimensional surface density distribution data of the sample to be detected based on the zero point of each pixel detector of the linear array detector and the calibration model, and determine the actual size corresponding to the single surface density data detected by each pixel detector of the linear array detector in the width direction and the tape running direction;

[0024] The ray source and the linear array detector are relatively fixed, and the sample to be detected is placed between the ray source and the linear array detector and can move relative to the ray source and the linear array detector.

[0025] A surface density full inspection system, comprising:

[0026] A ray source, wherein the ray source is an X / β-ray distribution source, comprising an encapsulating shell and a plurality of X / β-ray diverging sources distributed inside the encapsulating shell, wherein the rays emitted by the X / β-ray diverging source are constrained to diverge into a fan shape through their own source windows;

[0027] A linear array detector includes a plurality of pixel detectors for receiving rays emitted by a ray source and outputting attenuated two-dimensional signals, wherein each of the irradiation areas of the X / β-ray diverging sources is received and detected by a single pixel of the linear array detector;

[0028] A processor is configured to receive the two-dimensional signal output by the linear array detector, and calculate the two-dimensional surface density distribution data of the sample to be detected based on the zero point of each pixel detector of the linear array detector and the calibration model, and determine the actual size corresponding to the single surface density data detected by each pixel detector of the linear array detector in the width direction and the tape running direction;

[0029] The ray source and the linear array detector are relatively fixed, and the sample to be detected is placed between the ray source and the linear array detector and can move relative to the ray source and the linear array detector.

[0030] A surface density full inspection system, comprising:

[0031] A ray source, wherein the ray source is an X / β ray diverging source, and the rays emitted by the X / β ray diverging source are constrained to diverge into a fan shape through its own source window;

[0032] A linear array detector, comprising a plurality of pixel detectors, configured to receive the radiation emitted by the radiation source and output a two-dimensional signal after attenuation;

[0033] A processor is configured to receive the two-dimensional signal output by the linear array detector, and calculate the two-dimensional surface density distribution data of the sample to be detected based on the zero point of each pixel detector of the linear array detector and the calibration model, and determine the actual size corresponding to the single surface density data detected by each pixel detector of the linear array detector in the width direction and the tape running direction;

[0034] The ray source and the linear array detector are relatively fixed, and the sample to be detected is placed between the ray source and the linear array detector and can move relative to the ray source and the linear array detector.

[0035] Furthermore, the X / β ray diverging source constrains the rays into a line beam reaching the linear array detector by applying trapezoidal collimation.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] (1) The surface density of lithium electrode sheets and substrate films is fully tested. Compared with the lateral scanning spot check, the measurement system is more stable and there is no missed detection. The marks of abnormal surface density positions are removed, which significantly improves the surface density distribution consistency, total consistency and other product quality. The lithium electrode sheets after cutting can be sorted to improve the consistency of the battery.

[0038] (2) Feedback the full surface density detection data to the coating die head or substrate film production equipment in the previous process to adjust the production process parameters in real time, increase the supporting data for closed-loop regulation, and give full play to the role of closed-loop regulation;

[0039] (3) Improve the spatial resolution in the width direction and the tape direction of the surface density detection. In the actual line scan measurement, there is no need for a scanning mechanical motion device, which can improve the stability of the equipment's online operation and increase the stability of the surface density detection;

[0040] (4) Assisting lithium battery production to develop towards high capacity, high density and high speed, including but not limited to improving the performance of lithium batteries such as the physical properties, stability and uniformity of the electrode;

[0041] (5) The area density full inspection system composed of an X / β-ray line source and a linear array detector has a good spatial resolution and the best accuracy, but poor economic efficiency. It is suitable for scenes with high requirements for detection effects.

[0042] (6) The area density full inspection system composed of an X / β-ray distribution source and a linear array detector has a moderate spatial resolution, good accuracy, and moderate economy, and is suitable for scenarios with relatively balanced requirements in all aspects;

[0043] (7) The area density full inspection system composed of an X / β-ray divergent source and a linear array detector has the highest spatial resolution, moderate accuracy, and good economy, and is suitable for scenarios with high economic requirements;

[0044] (8) According to the detection requirements of the object to be detected, an appropriate full inspection system is selected, which expands the application scenarios of the surface density full inspection method proposed in the present invention and increases the practicality of the method. Regardless of which system is selected, the beneficial effects described in (1) to (4) are present. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] FIG1 is a flow chart of a method for full surface density inspection according to the present invention;

[0046] FIG2 is a schematic structural diagram of a surface density full inspection system according to embodiment 1 of the present invention;

[0047] FIG3 is a schematic structural diagram of a full surface density inspection system according to embodiment 2 of the present invention;

[0048] FIG4 is a schematic structural diagram of a full surface density inspection system according to embodiment 3 of the present invention;

[0049] FIG5 is a schematic diagram of the structure of the positive electrode sheet in Example 3 of the present invention;

[0050] FIG6 is a three-dimensional display effect of the full inspection of the surface density of the positive electrode sheet in Example 3 of the present invention;

[0051] FIG7 is a two-dimensional display effect of the full inspection of the surface density of the positive electrode sheet in Example 3 of the present invention;

[0052] FIG8 is a two-dimensional distribution diagram of the surface density of the positive electrode sheet after full inspection and restoration to the actual size in Example 3 of the present invention;

[0053] In the figure: 101, ray source; 102, sample to be detected; 103, collimation grid; 104, linear array detector; 201, ray source; 202, sample to be detected; 203, linear array detector; 301, ray source; 302, sample to be detected; 303, linear array detector. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the 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.

[0055] Please refer to Figure 1, a method for full surface density inspection includes the following steps:

[0056] (1) Zero point measurement: The ray source emits rays to the linear array detector, which includes several pixel detectors. Each pixel of the linear array detector detects the original intensity of the ray passing through the air and reaching the detector;

[0057] (2) Target detection object calibration: a sample with known surface density is placed at the detection object position. The radiation emitted by the radiation source penetrates the sample with known surface density and reaches the linear array detector. According to the attenuation law of the radiation beam, the corresponding relationship between the surface density of the sample with known surface density and the measurement signal is obtained to determine the calibration model.

[0058] (3) Actual line scan measurement: The sample to be tested is placed between the ray source and the linear array detector. The ray source and the linear array detector are relatively fixed, and the sample to be tested moves relative to the ray source and the linear array detector. The ray source irradiates the sample to be tested to form a light spot covering its entire width. The rays emitted by the ray source penetrate the sample to be tested and reach the linear array detector. The linear array detector outputs a two-dimensional signal after attenuation. According to the zero point, two-dimensional signal and calibration model of each pixel detector of the linear array detector, the two-dimensional surface density distribution data of the sample to be tested is obtained;

[0059] (4) Determine the actual size: determine the actual size of the single area density data obtained by each pixel detector of the linear array detector in the width direction and the tape direction, and further obtain the two-dimensional actual size of the sample corresponding to the two-dimensional area density distribution data;

[0060] (5) Error correction: This includes keeping the relative positions of the ray source and the linear array detector unchanged, moving them out of the detection object's belt zone, and measuring the zero point in real time; keeping the relative positions of the ray source and the linear array detector unchanged, moving them out of the detection object's belt zone, and correcting the detection results by measuring the standard film.

[0061] The principle of using X / β rays to measure surface density / thickness is based on the attenuation law of the ray beam when the ray passes through objects with different surface densities / thicknesses.

[0062] In step (2), the attenuation law of the ray beam satisfies the following formula: I = I0*e -λm

[0063] Wherein, I0 is the primary intensity of the ray measured in step (1), I is the intensity of the ray passing through the sample with known surface density measured in step (2), λ is the attenuation coefficient of the sample with known surface density per unit surface density for the ray, and m is the surface density. Since m is a known specific value, the specific value of λ can be obtained to obtain the calibration model;

[0064] Therefore, the calculation formula for the surface density m in step (3) is:

[0065] Therefore, the measurement signal There is a linear relationship between the surface density m and the surface density m, but this is applicable to the case of a single energy beam. For X / β rays with a continuous energy spectrum in actual situations, due to the ray hardening phenomenon after passing through the object, the surface density and the measurement signal are not completely linear within a larger surface density detection range. Therefore, it is necessary to use the least squares polynomial fitting method to the surface density of each pixel detector of the linear array detector and the measurement signal, where the fitting correlation coefficient R 2 >0.999, for each pixel of the ray array detector, calibration is performed, and the zero point I0 corresponding to each pixel and the calibration relationship of each pixel in step (2) are saved;

[0066] In actual situations, the surface density detector needs to work 24 / 7. The I0 in the zero point will change with the temperature, humidity and air density of the equipment environment, thus affecting the measurement signal. This will have an impact, which will eventually lead to errors in the surface density test results, so error correction is needed;

[0067] Specifically, error correction includes: setting a time interval of not less than 1 hour to keep the relative position of the ray source and the linear array detector unchanged, moving out of the detection object's belt zone, and measuring the zero point in real time. It can also measure the real-time temperature, humidity, and air density through sensors, and correct the zero point in real time through the correction model;

[0068] Set a time interval of not less than 24 hours to keep the relative position of the radiation source and the linear array detector unchanged, move the test object out of the belt zone, and correct the test results by measuring the standard piece, where the standard piece can be a single thickness standard piece with known surface density or a step thickness standard piece, and the material can be a metal standard piece or a plastic standard piece;

[0069] The actual size of the single area density data obtained by each pixel detector in step (4) in the tape running direction is: tape running speed / sampling frequency. Specifically, the tape running direction is the moving direction of the sample to be tested;

[0070] In step (5), the relative positions of the ray source and the linear array detector are kept unchanged, and the detection object is moved out of the belt conveyor area. The time interval for measuring the real-time zero point is not less than 1 hour. The relative positions of the ray source and the linear array detector are kept unchanged, and the detection object is moved out of the belt conveyor area. The time interval for correcting the detection result by measuring the standard film is not less than 24 hours.

[0071] Example 1

[0072] Please refer to FIG2 . In this embodiment, the radiation source is an X / β-ray source. Specifically, the β-ray source may be Kr85, Sr90, an electron accelerator, or the like. The linear array detector 104 may be any one of a gas ionization chamber detector, a scintillator detector, and a semiconductor detector. Depending on the energy of the type of radiation to be measured and the detection requirements, the appropriate detector type, material type, and size are selected. The size of a single pixel is between mm and cm. A collimating grid 103 is provided at the top of the linear array detector 104 to collimate the radiation emitted by the radiation source 101 so that the radiation enters the linear array detector 104 perpendicularly. The collimating grid 103 is made of a heavy metal or alloy such as lead or tungsten. The spacing between individual pixels is between mm and cm, and the spacing between individual pixels of the collimating grid 103 corresponds to the size of individual pixels of the linear array detector 104. The sample 102 to be detected is placed between the radiation source 101 and the collimating grid 103. Specifically, the sample 102 to be detected may be a lithium electrode sheet, a metal foil, a polymer film, or a foil used in the production of new batteries.

[0073] The actual size of the single area density data detected by each pixel detector in step (4) in the width direction is the single pixel spacing size of the linear array detector 104.

[0074] Referring to FIG. 2 , in this embodiment, a full area density inspection system applied to the full area density inspection method is proposed, comprising:

[0075] The ray source 101 is used to emit rays. The ray source 101 includes a plurality of X / β ray sources arranged in series. The β ray source can be specifically Kr85, Sr90, an electron accelerator, etc.

[0076] The linear array detector 104 includes a plurality of pixel detectors for receiving the radiation emitted by the radiation source 101 and outputting attenuated two-dimensional signals. The linear array detector 104 can be any type of gas ionization chamber detector, scintillator detector, semiconductor detector, etc.

[0077] The collimating grid 103 is used to collimate the rays emitted by the ray source 101. A single interval of the collimating grid 103 corresponds to a single pixel size of the linear array detector 104.

[0078] The processor is configured to receive the two-dimensional signal output by the linear array detector 104, and calculate the two-dimensional surface density distribution data of the sample to be detected 102 based on the zero point, the two-dimensional signal, and the calibration model of each pixel detector of the linear array detector 104, and determine the actual size of the single surface density data detected by each pixel detector of the linear array detector 104 in the width direction and the running direction.

[0079] The ray source 101 and the linear array detector 104 are relatively fixed, and the sample 102 to be detected is placed between the ray source 101 and the linear array detector 104 and can move relative to the ray source 101 and the linear array detector 104 .

[0080] Example 2

[0081] Please refer to Figure 3. The difference between this embodiment and Example 1 is that the ray source 301 is an X / β-ray distribution source, which includes a packaging shell and several X / β-ray diverging sources distributed inside the packaging shell. The rays emitted by the X / β-ray diverging source are constrained to diverge into a fan shape through its own source window. The irradiation area of ​​the several X / β-ray diverging sources is received and detected by a single pixel of the linear array detector 303. The size of the linear array detector 303 is at the mm to cm level. The sample 302 to be detected is placed between the ray source 301 and the linear array detector 303.

[0082] The actual size of the single area density data detected by each pixel detector in step (4) in the width direction is the single pixel spacing size of the linear array detector 303.

[0083] Referring to FIG. 3 , in this embodiment, a full area density inspection system applied to the full area density inspection method is proposed, comprising:

[0084] A ray source 301 is used to emit rays, and includes a packaging shell and a plurality of X / β ray diverging sources distributed inside the packaging shell;

[0085] The linear array detector 303 includes a plurality of pixel detectors, and is used to receive the radiation emitted by the radiation source 301 and output a two-dimensional signal after attenuation;

[0086] The processor is configured to receive the two-dimensional signal output by the linear array detector 303, and calculate the two-dimensional surface density distribution data of the sample to be detected 302 based on the zero point, the two-dimensional signal, and the calibration model of each pixel detector of the linear array detector 303, and determine the actual size of the single surface density data detected by each pixel detector of the linear array detector 303 in the width direction and the tape running direction.

[0087] The ray source 301 and the linear array detector 303 are relatively fixed, and the sample 302 to be detected is placed between the ray source 301 and the linear array detector 303 and can move relative to the ray source 301 and the linear array detector 303 .

[0088] Example 3

[0089] Referring to FIG. 4 , this embodiment differs from Embodiment 1 in that the radiation source 201 is a divergent X / β ray source. The radiation emitted by the divergent X / β ray source is constrained to diverge into a fan shape by its own source window, or further constrained into a linear beam that reaches the linear array detector 203 by adding a trapezoidal collimator. The added collimator is made of a heavy metal or alloy such as lead or tungsten to adjust the size of the fan beam. The sample 202 to be tested is placed between the radiation source 201 and the linear array detector 203. Since the size of the collimator grid is not limited, the size of a single pixel of the linear array detector 203 can be between tens of microns and centimeters.

[0090] Since the fan beam has a certain magnification ratio, the actual size of the sample 202 to be tested in step (4) in the width direction is:

[0091] Wherein, d is the actual size corresponding to the width direction of the sample to be detected 202, d0 is the single pixel interval size of the linear array detector 203, f is the magnification ratio, h1 is the distance from the focus of the ray source 201 to the linear array detector 203, and h2 is the distance from the focus of the ray source 201 to the sample to be detected 202.

[0092] Referring to FIG. 4 , in this embodiment, a full area density inspection system applied to the full area density inspection method is proposed, comprising:

[0093] The ray source 201 is used to emit rays, and the emitted rays are constrained to diverge into a fan shape through its own source window, or further constrained into a line beam reaching the linear array detector 203 by adding trapezoidal collimation;

[0094] The linear array detector 203 includes a plurality of pixel detectors for receiving the radiation emitted by the radiation source and outputting attenuated two-dimensional signals. The area irradiated by the X / β-ray diverging source is detected by a single pixel of the linear array detector 203.

[0095] The processor is configured to receive the two-dimensional signal output by the linear array detector 203, and calculate the two-dimensional surface density distribution data of the sample to be detected 202 based on the zero point, the two-dimensional signal, and the calibration model of each pixel detector of the linear array detector 203, and determine the actual size of the single surface density data detected by each pixel detector of the linear array detector 203 in the width direction and the running direction.

[0096] The ray source 201 and the linear array detector 203 are relatively fixed, and the sample 202 to be detected is placed between the ray source 201 and the linear array detector 203 and can move relative to the ray source 201 and the linear array detector 203 .

[0097] Please refer to Figure 5-8 and the following explanation will be given in conjunction with specific products.

[0098] Refer to Figure 5. From left to right, the positive electrode sheet consists of the substrate area, ceramic area, thinning area, coating area, thinning area, ceramic area, and substrate area. The positive electrode sheet was passed through the X-ray source and linear array detector at a conveyor speed of 1m / s, and the measurement time was 1s. The detection area density results can be displayed in three dimensions and two dimensions, as shown in Figures 6 and 7, respectively. In Figure 6, the X-axis is the width direction, and each pixel sensor of the linear array detector has an output; the Y-axis is the conveyor direction, with an output every millisecond; and the Z-axis is the area density value, in g / m 2 The height on the Z-axis reflects the size of the surface density. At the same time, the surface density value is represented by a color bar, and different color bars can be selected. In Figure 7, the X-axis is the width direction and the Y-axis is the tape running direction, which is the projection of Figure 6 on the XY plane. The surface density is directly displayed in a color map.

[0099] In the full surface density inspection result shown in Figure 7, from left to right, they are substrate area, ceramic area, thinning area, coating area, thinning area, ceramic area, and substrate area. The two-dimensional surface density distribution shown in Figure 7 is restored to a two-dimensional distribution of actual size. The display result is shown in Figure 8. The X-axis is the width direction, the actual size is 233mm, the Y-axis is the tape direction, the tape speed is 1m / s, the detection time is 1s, and the actual size is 1000mm.

[0100] The beneficial effects of the method and system for full area density inspection provided by the above embodiment include:

[0101] (1) The surface density of lithium electrode sheets and substrate films is fully tested. Compared with the lateral scanning spot check, the measurement system is more stable and there is no missed detection. The marks of abnormal surface density positions are removed, which significantly improves the surface density distribution consistency, total consistency and other product quality. The lithium electrode sheets after cutting can be sorted to improve the consistency of the battery.

[0102] (2) Feedback the full surface density detection data to the coating die head or substrate film stretching and extrusion equipment in the previous process to adjust the production process parameters in real time, increase the supporting data for closed-loop regulation, and give full play to the role of closed-loop regulation;

[0103] (3) Improve the spatial resolution in the width direction and the tape direction of the surface density detection. In the actual line scan measurement, there is no need for a scanning mechanical motion device, which can improve the stability of the equipment's online operation and increase the stability of the surface density detection;

[0104] (4) Assisting lithium battery production to develop towards high capacity, high density and high speed, including but not limited to improving the performance of lithium batteries such as the physical properties, stability and uniformity of the electrode;

[0105] (5) The area density full inspection system composed of an X / β-ray line source and a linear array detector has a good spatial resolution and the best accuracy, but poor economic efficiency. It is suitable for scenes with high requirements for detection effects.

[0106] (6) The area density full inspection system composed of an X / β-ray distribution source and a linear array detector has a moderate spatial resolution, good accuracy, and moderate economy, and is suitable for scenarios with relatively balanced requirements in all aspects;

[0107] (7) The area density full inspection system composed of an X / β-ray divergent source and a linear array detector has the highest spatial resolution, moderate accuracy, and good economy, and is suitable for scenarios with high economic requirements;

[0108] (8) According to the detection requirements of the object to be detected, an appropriate full inspection system is selected, which expands the application scenarios of the surface density full inspection method proposed in the present invention and increases the practicality of the method. Regardless of which system is selected, the beneficial effects described in (1) to (4) are present.

[0109] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A method for full surface density inspection, characterized in that: The following steps are included: (1) Zero point measurement: the radiation source emits radiation to a linear array detector, which includes a plurality of pixel detectors, and each pixel detector of the linear array detector detects the primary intensity of the radiation when it passes through the air and reaches the detector; (2) Target detection object calibration: a sample with known surface density is placed at the detection object position, and the radiation emitted by the radiation source penetrates the sample with known surface density to reach the linear array detector. According to the attenuation law of the radiation beam, the corresponding relationship between the surface density of the sample with known surface density and the measurement signal is obtained to determine the calibration model; (3) Actual line scan measurement: the sample to be tested is placed between the ray source and the linear array detector, the ray source and the linear array detector are relatively fixed, the sample to be tested moves relative to the ray source and the linear array detector, the ray source irradiates the sample to be tested to form a light spot covering its entire width, the ray emitted by the ray source penetrates the sample to be tested and reaches the linear array detector, the linear array detector outputs an attenuated two-dimensional signal, and the two-dimensional surface density distribution data of the sample to be tested is obtained according to the zero point of each pixel detector of the linear array detector and the calibration model; (4) determining the actual size: determining the actual size corresponding to the single surface density data detected by each pixel detector of the linear array detector in the width direction and the tape running direction, and further obtaining the two-dimensional actual size of the sample corresponding to the two-dimensional surface density distribution data; (5) Error correction: including keeping the relative position of the ray source and the linear array detector unchanged, moving them out of the detection object's belt zone, measuring the zero point in real time and updating it; keeping the relative position of the ray source and the linear array detector unchanged, moving them out of the detection object's belt zone, and correcting the detection result by measuring the standard film.

2. A method for full surface density inspection according to claim 1, characterized in that: In the step (2), the attenuation law of the ray beam satisfies the following formula: I = I0*e -λm Where I0 is the primary intensity of the ray measured in step (1), and I is the intensity of the ray passing through measured in step (2). The ray intensity of the sample with known surface density, λ is the attenuation coefficient of the sample with known surface density per unit surface density, and m is the surface density; Therefore, the calculation formula of the surface density m in step (3) is:

3. A method for full surface density inspection according to claim 2, characterized in that: The surface density of each pixel detector of the linear array detector and the measured signal are fitted by a polynomial using the least squares method, where the fitting correlation coefficient R 2 >0.

995.

4. A method for full surface density inspection according to claim 1, characterized in that: The actual size of the single surface density data detected by each pixel detector in the step (4) in the tape running direction corresponds to: tape running speed / sampling frequency.

5. A method for full surface density inspection according to any one of claims 1 to 4, characterized in that: The actual size of the single surface density data detected by each pixel detector in the step (4) in the width direction corresponds to the single pixel spacing size of the linear array detector.

6. A method for full surface density inspection according to any one of claims 1 to 4, characterized in that: The actual size of the single surface density data detected by each pixel detector in step (4) in the width direction is: Among them, d is the actual size corresponding to the width direction of the sample to be detected, d0 is the single pixel spacing size of the linear array detector, f is the magnification ratio, h1 is the distance from the focus of the ray source to the linear array detector, and h2 is the distance from the focus of the ray source to the sample to be detected.

7. A surface density full inspection system applied to a surface density full inspection method according to any one of claims 1 to 5, characterized in that: include: A ray source, wherein the ray source is an X / β ray source; A linear array detector, comprising a plurality of pixel detectors, for receiving the rays emitted by the ray source and outputting attenuated two-dimensional signals; A collimating grid, used for collimating the rays emitted by the ray source, wherein a single interval of the collimating grid corresponds to a single pixel size of the linear array detector; A processor is used to receive the two-dimensional signal output by the linear array detector, and calculate the two-dimensional surface density distribution data of the sample to be detected according to the zero point and calibration model of each pixel detector of the linear array detector, and determine the actual size corresponding to the single surface density data detected by each pixel detector of the linear array detector in the width direction and the tape running direction; The ray source and the linear array detector are relatively fixed, and the sample to be detected is placed between the ray source and the linear array detector and can move relative to the ray source and the linear array detector.

8. A surface density full inspection system applied to a surface density full inspection method according to any one of claims 1 to 5, characterized in that: include: A ray source, wherein the ray source is an X / β-ray distribution source, and the X / β-ray distribution source comprises a packaging shell and a plurality of X / β-ray divergence sources distributed inside the packaging shell, wherein the rays emitted by the X / β-ray divergence source are constrained by their own source windows to have a fan-shaped divergence shape; The linear array detector comprises a plurality of pixel detectors, which are used to receive the rays emitted by the ray source and output the attenuated two-dimensional signals. The irradiation areas of the plurality of X / β-ray divergent sources are correspondingly received and detected by a single pixel of the linear array detector. A processor is used to receive the two-dimensional signal output by the linear array detector, and calculate the two-dimensional surface density distribution data of the sample to be detected according to the zero point and calibration model of each pixel detector of the linear array detector, and determine the actual size corresponding to the single surface density data detected by each pixel detector of the linear array detector in the width direction and the tape running direction; The ray source and the linear array detector are relatively fixed, and the sample to be detected is placed between the ray source and the linear array detector and can move relative to the ray source and the linear array detector.

9. A surface density full inspection system applied to a surface density full inspection method as claimed in any one of claims 1, 2, 3, 4 and 6, characterized in that: include: A ray source, wherein the ray source is an X / β ray divergence source, and the rays emitted by the X / β ray divergence source are constrained by their own source window to have a fan-shaped divergence shape; A linear array detector, comprising a plurality of pixel detectors, for receiving the rays emitted by the ray source and outputting attenuated two-dimensional signals; A processor is used to receive the two-dimensional signal output by the linear array detector, and calculate the two-dimensional surface density distribution data of the sample to be detected according to the zero point and calibration model of each pixel detector of the linear array detector, and determine the actual size corresponding to the single surface density data detected by each pixel detector of the linear array detector in the width direction and the tape running direction; The ray source and the linear array detector are relatively fixed, and the sample to be detected is placed between the ray source and the linear array detector and can move relative to the ray source and the linear array detector.

10. A surface density full inspection system according to claim 9, characterized in that: The X / β-ray diverging source constrains the rays into a line beam reaching the linear array detector by externally applied trapezoidal collimation.

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