Method for testing packaging defects of photovoltaic adhesive film

Abstract

The invention belongs to the technical field of photovoltaic adhesive film packaging defect detection, and particularly relates to a photovoltaic adhesive film packaging defect test method which comprises the following steps: step 1, packaging a photovoltaic adhesive film on a photovoltaic cell according to a preset packaging process to prepare a test sample; 2, performing infrared thermal imaging detection on the test sample to obtain infrared thermal imaging data of the test sample, performing digital image processing on the infrared thermal imaging data, and judging whether packaging defects exist or not; if the packaging defect exists, the position and the range of the defect are further determined, and otherwise, the test sample is output as a qualified product; 3, performing ultrasonic detection on the test sample with the packaging defect, and outputting an ultrasonic detection result; and 4, evaluating and analyzing the packaging defects of the photovoltaic adhesive film. According to the invention, two methods of infrared thermal imaging detection and ultrasonic detection are combined, so that packaging defects can be detected more comprehensively and accurately; and the detection accuracy and efficiency are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of photovoltaic film packaging defect detection, and in particular relates to a photovoltaic film packaging defect testing method. Background Art

[0002] With the rapid development of photovoltaic products, the quality and reliability of photovoltaic modules have become particularly important. As one of the key materials for photovoltaic module encapsulation, the encapsulation quality of photovoltaic film directly affects the performance and service life of photovoltaic modules. However, in the encapsulation process of photovoltaic film, there are various defects, such as bubbles, delamination, wrinkles, impurities, etc. These defects will increase the risk of module failure. Therefore, an effective testing method is needed to detect the encapsulation defects of photovoltaic film.

[0003] At present, the commonly used photovoltaic film packaging defect testing methods mainly include appearance inspection, electrical performance test and thermal cycle test. Although the appearance inspection is simple and intuitive, it can only detect obvious defects on the surface, and it is difficult to find small internal defects; the electrical performance test can reflect the overall performance of the photovoltaic module, but it cannot accurately locate the location and type of defects; the thermal cycle test can simulate the temperature changes of the module in actual use, but the test cycle is long and the cost is high.

[0004] Commonly used photovoltaic film encapsulation defect testing methods have many limitations. For example, it is difficult to detect tiny internal defects through visual inspection, electrical testing cannot accurately locate the location and type of defects, and the temperature and humidity cycle test has a long cycle and high cost. For this reason, we propose a photovoltaic film encapsulation defect testing method. The present invention aims to provide a testing method that can quickly and accurately detect the location, type, size and other information of photovoltaic film encapsulation defects, so as to solve the shortcomings of existing testing methods and provide strong support for improving the encapsulation quality of photovoltaic modules. Summary of the invention

[0005] The purpose of the present invention is to provide a testing method for photovoltaic film encapsulation defects, which can quickly and accurately detect information such as the location, type and size of photovoltaic film encapsulation defects, so as to solve the shortcomings of existing testing methods and provide strong support for improving the encapsulation quality of photovoltaic modules.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A method for testing defects of photovoltaic film packaging comprises the following steps:

[0008] Step 1: Prepare a test sample, and encapsulate the photovoltaic film on the photovoltaic cell according to a predetermined encapsulation process to make a test sample;

[0009] Step 2: Perform infrared thermal imaging detection on the test sample to obtain infrared thermal imaging data of the test sample, and perform digital image processing on the infrared thermal imaging data to determine whether there is a packaging defect; if there is a packaging defect, further determine the location and range of the defect, otherwise output the test sample as a qualified product;

[0010] Step 3: For the test sample with packaging defects, ultrasonic testing is performed and the ultrasonic testing results are output, wherein the ultrasonic testing results include defect type, defect location and defect size;

[0011] Step 4: Based on the infrared thermal imaging data and ultrasonic testing results, the packaging defects of the photovoltaic film are evaluated and analyzed, and detailed information on the defects and improvement suggestions are given.

[0012] Preferably, in step 2, the specific process of performing infrared thermal imaging detection on the test sample is as follows:

[0013] Step 201: placing a test sample in a detection area of ​​an infrared thermal imager;

[0014] Step 202: applying a current that matches the test sample to the test sample to make the test sample heat up, acquiring a surface temperature distribution image of the test sample through an infrared thermal imager, and obtaining infrared thermal imaging data of the test sample;

[0015] Step 203: Perform digital image processing and analysis on the surface temperature distribution image of the test sample in the infrared thermal imaging data of the test sample, and determine whether there is a packaging defect based on the uniformity of the surface temperature distribution of the test sample. If there is a packaging defect, further determine the location and range of the defect. Otherwise, output the test sample as a qualified product.

[0016] Preferably, in step 203, the specific process of performing digital image processing and analysis on the surface temperature distribution image of the test sample in the infrared thermal imaging data of the test sample is as follows:

[0017] Step 2031: converting the surface temperature distribution image of the test sample into a dot matrix, wherein each pixel point includes pixel point coordinate data and pixel point value data, and the pixel point value data corresponds to temperature data;

[0018] Step 2302: Perform Fourier transform on the surface temperature distribution dot map, and convert the surface temperature distribution dot map from the spatial domain to the frequency domain;

[0019] Step 2303: determine whether there is a high-frequency component based on the frequency domain image. If there is no high-frequency component, the test sample is a qualified product. If there is a high-frequency component, the test sample is defective.

[0020] Step 2304: For the surface temperature distribution image with high-frequency components, specifically, the sudden change in pixel values ​​corresponding to the defect details that are not easily perceived in the spatial domain is manifested as a high-frequency component in the frequency domain; by analyzing the high-frequency components, it is possible to detect and locate the sudden change pixel points corresponding to the defects in the surface temperature distribution dot matrix image;

[0021] Step 2305: Finally, the pixel position and range corresponding to the defect in the surface temperature distribution image of the test sample are output.

[0022] Preferably, the step 3 specifically includes the following steps:

[0023] Step 301: placing the test sample under the detection probe of an ultrasonic detector; and aligning the defect position of the test sample with the detection probe of the ultrasonic detector;

[0024] Step 302: the detection probe of the ultrasonic detector emits ultrasonic waves, and after the ultrasonic waves are reflected by the test sample, the detection probe of the ultrasonic detector receives the reflected waves;

[0025] Step 303: Determine the type and size of the defect based on the signal characteristics of the reflected wave.

[0026] Preferably, a plexiglass delay block is provided on the detection probe of the ultrasonic detector in step 301.

[0027] During the detection process, no surface detection blind area is allowed, and one of the disadvantages of ultrasonic detection is the existence of detection blind area. In order to avoid the existence of detection blind area and improve the resolution of probe detection, water bag probe or straight probe with delay block is selected to avoid the existence of blind area. The delay block made of organic glass is cheaper and easier to replace than the water bag probe. Therefore, the straight probe with delay block is selected for detection.

[0028] Preferably, in step 302, the detection probe of the ultrasonic detector performs ultrasonic C-scan detection, the detection probe center frequency is 0.5MHz, the chip diameter is φ25mm, the sampling interval is 1mm, and the scanning speed is 100mm / s; wherein, the scanning repeatability accuracy of the detection probe of the ultrasonic detector is δx=±0.1mm, δy=±0.1mm, δz=±0.02mm.

[0029] A photovoltaic film packaging defect testing device comprises an infrared imaging testing mechanism and an ultrasonic testing mechanism. The infrared imaging testing mechanism comprises a power supply and an infrared imager, and the ultrasonic testing mechanism comprises a placement platform and an ultrasonic detector.

[0030] An electronic device includes a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes a method for testing defects of photovoltaic film packaging.

[0031] A non-volatile computer-readable storage medium containing a computer program, when the computer program is executed by a processor, causes the processor to execute a method for testing defects of photovoltaic film packaging.

[0032] The technical effects achieved by the present invention are:

[0033] In the present invention, the detection range is precisely locked: by combining the two methods of infrared thermal imaging detection and ultrasonic detection, packaging defects can be detected more comprehensively and accurately; infrared thermal imaging detection can detect surface and shallow defects, and ultrasonic detection can deeply detect internal defects of samples, thereby improving the accuracy and efficiency of detection.

[0034] In the present invention, infrared thermal imaging detection can obtain the surface temperature distribution and morphology of the test sample non-contactly and over a large area, quickly discover problems, and has a high sensitivity for discovering surface and shallow packaging defects; ultrasonic detection can deeply detect defects inside the sample and provide more detailed defect information.

[0035] The testing method of the present invention can effectively evaluate and monitor the packaging quality of photovoltaic adhesive films, timely discover and solve problems in the packaging process, improve the reliability and stability of photovoltaic modules, and extend their service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flow chart of a method for testing defects of photovoltaic film packaging according to the present invention;

[0037] Figure 2 This is a schematic diagram of infrared imaging testing in a method for testing defects in photovoltaic film packaging according to the present invention;

[0038] Figure 3 It is a schematic diagram of ultrasonic detection in a method for testing defects of photovoltaic film packaging according to the present invention;

[0039] Figure 4 is a thermal distribution diagram of a certain abnormal photovoltaic chip under infrared imaging in an embodiment of the present invention;

[0040] Figure 5 is a spectrum of a certain abnormal photovoltaic chip under ultrasonic imaging in an embodiment of the present invention;

[0041] Figure 6 It is a schematic diagram of a 156mm×156mm test sample of an abnormal photovoltaic chip in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention.

[0043] like Figure 1-6 As shown, a method for testing defects of photovoltaic film packaging includes the following steps:

[0044] Step 1: Prepare the test sample, and encapsulate the photovoltaic film on the photovoltaic cell according to the predetermined encapsulation process to make the test sample.

[0045] Step 2: Perform infrared thermal imaging detection on the test sample to obtain infrared thermal imaging data of the test sample, and perform digital image processing on the infrared thermal imaging data to determine whether there is a packaging defect; if there is a packaging defect, further determine the location and range of the defect, otherwise output the test sample as a qualified product;

[0046] Step 201: placing a test sample in a detection area of ​​an infrared thermal imager;

[0047] Step 202: applying a current that matches the test sample to the test sample to make the test sample heat up, and obtaining a surface temperature distribution image of the test sample through an infrared thermal imager to obtain infrared thermal imaging data of the test sample;

[0048] Step 203: Perform digital image processing and analysis on the surface temperature distribution image of the test sample in the infrared thermal imaging data of the test sample, and determine whether there is a packaging defect based on the uniformity of the surface temperature distribution of the test sample. If there is a packaging defect, further determine the location and range of the defect. Otherwise, output the test sample as a qualified product.

[0049] In step 203, the specific process of digital image processing and analysis of the surface temperature distribution image of the test sample in the infrared thermal imaging data of the test sample is as follows:

[0050] Step 2031: converting the surface temperature distribution image of the test sample into a dot matrix image, where each pixel point contains pixel point coordinate data and pixel point value data, and the pixel point value data corresponds to temperature data;

[0051] Step 2302: Perform Fourier transform on the surface temperature distribution dot map, and convert the surface temperature distribution dot map from the spatial domain to the frequency domain;

[0052] Step 2303: determine whether there is a high-frequency component based on the frequency domain image. If there is no high-frequency component, the test sample is a qualified product. If there is a high-frequency component, the test sample is defective.

[0053] Step 2304: For the surface temperature distribution image with high-frequency components, specifically, the sudden change in pixel values ​​corresponding to the defect details that are not easily perceived in the spatial domain is manifested as a high-frequency component in the frequency domain; by analyzing the high-frequency components, it is possible to detect and locate the sudden change pixel points corresponding to the defects in the surface temperature distribution dot matrix image;

[0054] Step 2305: Finally, the pixel position and range corresponding to the defect in the surface temperature distribution image of the test sample are output.

[0055] In the present invention, in actual use, f(x, y) represents an image of infrared thermal imaging of a test sample with a size of M×N, and the discrete Fourier transform of f(x, y) can be expressed as:

[0056] Where: x, y are the horizontal and vertical coordinates of the image in the spatial domain; F(u, v) is the frequency domain image spectrum. Usually, F(u, v) is a complex-valued function of two real frequency variables u and v, with frequency u corresponding to the x-axis and frequency v corresponding to the y-axis. The power spectrum after the change is: P(u, v) = R 2 (u,v)+I 2 (u, v); where: R(u, v), I(u, v) represent the real part and imaginary part of F(u, v) respectively; then a certain number of power spectrum maps are randomly selected as training samples, and the FastICA algorithm is used to decompose them to generate a certain number of eigenvectors, and these vectors constitute a subspace.

[0057] In this embodiment, the decomposition process of the FastICA algorithm is as follows: the two-dimensional image (K rows, L columns) is stacked row by row into a row vector x of N=K×L dimensions i , x i ∈R N , M images form a matrix N=[x T1 , x T2 , …, x TM ] T ; Assume that these M images are also linear combinations of M statistically independent basis images, that is: X = AS, where each row of S represents a basis image of size K × L, A is a mixing matrix, and use FastICA to find the separation matrix W, so that the row vectors of the output Y = WX are as independent as possible, that is, Y is an approximation of S; Y can form a subspace, and the image to be identified is projected into this space, that is, it is represented by a linear combination of this set of independent basis images. Let d be the image to be identified (column vector), then: Where: α i The image d to be identified is in the basis vector y iThe projection coefficient in the direction can be used to design an appropriate classifier to realize image recognition. After the above processing, the original K×L dimensional image is reduced to M dimension, and the feature extraction function is realized. Finally, it is judged whether there is a high-frequency component based on the extracted features. If there is no high-frequency component, the test sample is a qualified product. If there is a high-frequency component, the test sample is defective. For the surface temperature distribution image with high-frequency components, the pixel value mutation corresponding to the defect details that are not easy to detect in the spatial domain is manifested as a high-frequency component in the frequency domain. By analyzing the high-frequency components, the mutation pixel points corresponding to the defects of the surface temperature distribution dot matrix can be detected and located.

[0058] In the present invention, the fast Fourier transform (FFT) power spectrum features have strong descriptive ability, combined with a multi-category support vector machine with strong classification ability, it can accurately identify whether defects occur and the specific location of the defects based on the infrared imaging of the surface after photovoltaic film encapsulation.

[0059] Step 3: For the test samples with packaging defects, ultrasonic testing is performed again, and the ultrasonic testing results are output. The ultrasonic testing results include defect type, defect location and defect size;

[0060] Step 301: placing a test sample under a detection probe of an ultrasonic detector; and aligning the defect position of the test sample with the detection probe of the ultrasonic detector;

[0061] Step 302: The detection probe of the ultrasonic detector emits ultrasonic waves, and after the ultrasonic waves are reflected by the test sample, the detection probe of the ultrasonic detector receives the reflected waves;

[0062] Step 303: Determine the type and size of the defect based on the signal characteristics of the reflected wave.

[0063] In this embodiment, the core control unit of the ultrasonic detection mechanism used adopts FPGA chip, and the accurate emission of ultrasonic signal is realized by controlling the MAX4940 circuit in the transmitting module; to ensure the signal quality, the limiting circuit and the variable gain amplifier circuit are introduced, the signal is adjusted by the limiting circuit, the probe generates ultrasonic wave to perform the defect detection task, and the reflected signal is received by the ultrasonic transducer, and the signal quality is enhanced by the variable gain amplifier circuit; by introducing these two circuits, the reflected signal is effectively processed, and the accuracy of the detection is improved; and FPGA is used as a data processing unit to organize information and transmit it to the host computer through the USB interface to realize the real-time display of the waveform; at the same time, a VGA video display module is designed, and the system sampling is output to FPGA through LVDS, and the VGA video display module realizes high-color VGA display, so the 16-bit high-color VGA display enables the operator to observe the detection results in real time; the serial communication part adopts asynchronous serial communication mode, and realizes data transmission through USB to serial port, which ensures the stability and reliability of the ultrasonic detection mechanism. Finally, FIFO transmission is introduced to improve the transmission efficiency of ADC sampling data, and the FPGA frequency is fully utilized, and finally the accurate ultrasonic detection of the sample to be detected is realized.

[0064] Step 4: Based on the infrared thermal imaging data and ultrasonic testing results, the packaging defects of the photovoltaic film are evaluated and analyzed, and detailed information on the defects and improvement suggestions are given.

[0065] Among them, in step 301, a plexiglass delay block is provided on the detection probe of the ultrasonic detector; surface detection blind spots are not allowed to exist during the detection process, and one of the disadvantages of ultrasonic detection is the existence of detection blind spots; in order to avoid the existence of detection blind spots and improve the resolution of probe detection, a water bag probe or a straight probe with a delay block is selected to avoid the existence of blind spots, and the delay block made of plexiglass is cheaper and easier to replace than the water bag probe; therefore, a straight probe with a delay block is selected for detection.

[0066] Among them, in step 302, the detection probe of the ultrasonic detector performs ultrasonic C-scan detection, the detection probe center frequency is 0.5MHz, the chip diameter is φ25mm, the sampling interval is 1mm, and the scanning speed is 100mm / s; among them, the detection probe of the ultrasonic detector has a scanning repetition accuracy of δx=±0.1mm, δy=±0.1mm, and δz=±0.02mm.

[0067] In the present invention,

[0068] The working principle of the present invention is as follows: Step 1: prepare a test sample, encapsulate a photovoltaic adhesive film on a photovoltaic cell sheet according to a predetermined encapsulation process to prepare a test sample;

[0069] Step 2: If Figure 2Perform infrared thermal imaging test on the test sample, place the test sample in the detection area of ​​the infrared thermal imager, apply a certain current to make the test sample heat up, and obtain the surface temperature distribution image of the test sample through the infrared thermal imager; analyze the infrared thermal imaging test results, and judge whether there is a packaging defect based on the uniformity of the surface temperature distribution of the test sample; if there is an abnormal temperature area, it is considered that there is a packaging defect, and the location and approximate range of the defect are further determined;

[0070] Step 3: If Figure 3 For test samples with packaging defects, ultrasonic testing is used for further analysis. The test sample is placed under the detection probe of the ultrasonic detector, ultrasonic waves are emitted and reflected waves are received. The type and size of the defect are determined based on the signal characteristics of the reflected waves.

[0071] Step 4: Based on the results of infrared thermal imaging and ultrasonic testing, the packaging defects of the photovoltaic film are evaluated and analyzed, and detailed information on the defects and improvement suggestions are given.

[0072] Example: Step 1: Prepare test samples: Select 4 types of single / polycrystalline silicon photovoltaic cells with different sizes: 156mm×104mm, 156mm×156mm, 156mm×208mm, and 156mm×260mm, encapsulate the photovoltaic film on the cell according to the lamination process, reserve the positive and negative terminals, and make test samples.

[0073] Step 2: Infrared thermal imaging detection: Place the prepared test sample in the detection area of ​​the infrared thermal imager. Due to the different specifications and models of various batteries, a constant current source with power output that meets the above 4 requirements and is adjustable is required. Apply the corresponding current to the test sample through a DC power supply to make it heat up; the detection temperature range of the infrared thermal imager is set to 10℃-80℃, and the resolution is above 0.03℃; aim the lens at the test sample, control the power-on time within 30 seconds, and obtain the surface temperature distribution image of the test sample on the computer screen through the software. It can be observed that there is an area with a large temperature difference in the upper left corner of the 156mm×156mm test sample and in the middle of the 156mm×208mm test sample, such as Figure 4 As shown; the blue color in the image represents low temperature, and the red color represents high temperature; the temperature is obviously lower than the surrounding area.

[0074] Step 3: Ultrasonic testing: Place the 156mm×156mm test sample with temperature anomaly under the detection probe of the ultrasonic detector and adjust the ultrasonic frequency for testing; the test results show that if Figure 5 as well as Figure 6As shown, there is an impurity defect in the temperature anomaly area, and the length of the morphology is about 5mm; another 156mm×208mm test sample was ultrasonically tested in the same way, and the results showed that there was a delamination defect in the area, and the delamination area was about 10mm×10mm.

[0075] Step 4: Comprehensive evaluation: According to the results of infrared thermal imaging and ultrasonic testing, the packaging defect of the 156mm×156mm photovoltaic film is evaluated to be a fiber impurity with a length of about 5mm, located in the upper left corner of the test sample; it is recommended that the production department optimize the workshop environment and improve the cleanliness of the workshop. Dust removal must be carried out before personnel enter the production workshop to reduce the introduction of impurities; the packaging defect of the 156mm×208mm photovoltaic film is a delamination with an area of ​​about 10mm×10mm, located in the middle area of ​​the test sample; it is recommended to adjust the ratio of the packaging material and the process parameters to enhance the adhesion between the film and the battery cell to avoid the occurrence of delamination.

[0076] In the present invention, the detection range is precisely locked: by combining the two methods of infrared thermal imaging detection and ultrasonic detection, packaging defects can be detected more comprehensively and accurately; infrared thermal imaging detection can detect surface and shallow defects, and ultrasonic detection can deeply detect internal defects of samples, thereby improving the accuracy and efficiency of detection.

[0077] In the present invention, infrared thermal imaging detection can obtain the surface temperature distribution and morphology of the test sample non-contactly and over a large area, quickly discover problems, and has a high sensitivity for discovering surface and shallow packaging defects; ultrasonic detection can deeply detect defects inside the sample and provide more detailed defect information.

[0078] The testing method of the present invention can effectively evaluate and monitor the packaging quality of photovoltaic adhesive films, timely discover and solve problems in the packaging process, improve the reliability and stability of photovoltaic modules, and extend their service life.

[0079] A photovoltaic film packaging defect testing device comprises an infrared imaging testing mechanism and an ultrasonic testing mechanism. The infrared imaging testing mechanism comprises a power supply and an infrared imager, and the ultrasonic testing mechanism comprises a placement platform and an ultrasonic detector.

[0080] An electronic device includes a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes a method for testing defects of photovoltaic film packaging.

[0081] The electronic device further includes a communication interface and a bus; wherein the processor, the memory, and the communication interface can communicate with each other through the bus. The communication interface can be used for information transmission. The processor can call the logic instructions in the memory to execute the method of the above embodiment. In addition, the logic instructions in the above memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product.

[0082] A non-volatile computer-readable storage medium containing a computer program, when the computer program is executed by a processor, causes the processor to execute a method for testing defects of photovoltaic film packaging.

[0083] Among them, the memory, as a computer-readable storage medium, can be used to store software programs, computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present application. The processor executes functional applications and data processing by running software programs, instructions and modules stored in the memory, that is, implementing the method in the above method embodiment. The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory may include a high-speed random access memory and may also include a non-volatile memory. The embodiment of the present application also provides a computer-readable storage medium, in which a computer-executable instruction is stored, and the computer-executable instruction is used to implement the test method described in any embodiment when executed by the processor. The embodiment of the present application also provides a computer program product, including a computer program, which implements the test method provided in the above embodiment when executed by the processor.

[0084] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. A method for testing defects in photovoltaic film packaging, characterized in that: The following steps are involved: Step 1: Prepare a test sample, and encapsulate the photovoltaic film on the photovoltaic cell according to a predetermined encapsulation process to make a test sample; Step 2: Perform infrared thermal imaging detection on the test sample to obtain infrared thermal imaging data of the test sample, and perform digital image processing on the infrared thermal imaging data to determine whether there is a packaging defect; if there is a packaging defect, further determine the location and range of the defect, otherwise output the test sample as a qualified product; Step 3: For the test sample with packaging defects, ultrasonic testing is performed and the ultrasonic testing results are output, wherein the ultrasonic testing results include defect type, defect location and defect size; Step 4: Based on the infrared thermal imaging data and ultrasonic testing results, the packaging defects of the photovoltaic film are evaluated and analyzed, and detailed information on the defects and improvement suggestions are given.

2. A method for testing defects of photovoltaic film encapsulation according to claim 1, characterized in that: In step 2, the specific process of performing infrared thermal imaging detection on the test sample is as follows: Step 201: placing a test sample in a detection area of ​​an infrared thermal imager; Step 202: applying a current that matches the test sample to the test sample to make the test sample heat up, acquiring a surface temperature distribution image of the test sample through an infrared thermal imager, and obtaining infrared thermal imaging data of the test sample; Step 203: Perform digital image processing and analysis on the surface temperature distribution image of the test sample in the infrared thermal imaging data of the test sample, and determine whether there is a packaging defect based on the uniformity of the surface temperature distribution of the test sample. If there is a packaging defect, further determine the location and range of the defect. Otherwise, output the test sample as a qualified product.

3. A method for testing defects of photovoltaic film encapsulation according to claim 2, characterized in that: In step 203, the specific process of digital image processing and analysis of the surface temperature distribution image of the test sample in the infrared thermal imaging data of the test sample is as follows: Step 2031: converting the surface temperature distribution image of the test sample into a dot matrix, wherein each pixel point includes pixel point coordinate data and pixel point value data, and the pixel point value data corresponds to temperature data; Step 2302: Perform Fourier transform on the surface temperature distribution dot matrix diagram to convert the surface temperature distribution dot matrix diagram from the spatial domain to the frequency domain; Step 2303: determine whether there is a high-frequency component based on the frequency domain image. If there is no high-frequency component, the test sample is a qualified product. If there is a high-frequency component, the test sample is defective. Step 2304: for the surface temperature distribution image with high-frequency components, by analyzing the high-frequency components, it is possible to detect and locate the mutation pixel points corresponding to the defects in the surface temperature distribution dot matrix diagram; Step 2305: Finally, the pixel position and range corresponding to the defect in the surface temperature distribution image of the test sample are output.

4. The method for testing defects of photovoltaic film encapsulation according to claim 1, characterized in that: The step 3 specifically includes the following steps: Step 301: placing the test sample under the detection probe of an ultrasonic detector; and aligning the defect position of the test sample with the detection probe of the ultrasonic detector; Step 302: the detection probe of the ultrasonic detector emits ultrasonic waves, and after the ultrasonic waves are reflected by the test sample, the detection probe of the ultrasonic detector receives the reflected waves; Step 303: Determine the type and size of the defect based on the signal characteristics of the reflected wave.

5. A method for testing defects of photovoltaic film encapsulation according to claim 4, characterized in that: In step 301, a plexiglass delay block is provided on the detection probe of the ultrasonic detector.

6. A method for testing defects of photovoltaic film encapsulation according to claim 4, characterized in that: In step 302, the detection probe of the ultrasonic detector performs ultrasonic C-scan detection; the detection probe center frequency is 0.5MHz, the chip diameter is φ25mm, the sampling interval is 1mm, and the scanning speed is 100mm / s; the detection probe of the ultrasonic detector has a scanning repetition accuracy of δx=±0.1mm, δy=±0.1mm, and δz=±0.02mm.

7. A photovoltaic film encapsulation defect testing device, characterized in that: It comprises an infrared imaging test mechanism and an ultrasonic test mechanism. The infrared imaging test mechanism comprises a power supply and an infrared imager, and the ultrasonic test mechanism comprises a placement platform and an ultrasonic detector.

8. An electronic device, characterized in that: The invention comprises a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the testing method according to any one of claims 1 to 6.

9. A non-volatile computer-readable storage medium containing a computer program, characterized in that: When the computer program is executed by a processor, the processor is caused to perform the testing method according to any one of claims 1 to 6.

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