Sample analysis method and system for TFT-LCD screen edge white type mura

Abstract

The present application relates to the technical field of defect detection, more specifically, to a TFT-LCD screen edge white type mura sample analysis method and system, adopting dust-free dry compressed air to remove surface dust of the TFT-LCD screen, performing cutting work of the ultrasonic knife along the screen frame of the TFT-LCD screen to separate the shell and the main body of the TFT-LCD screen, performing step-by-step separation processing on the main body of the TFT-LCD screen to obtain a plurality of structural assemblies, performing abnormal area partition cutting on the upper polarizing plate, the flexible printed circuit board and the reflective sheet in the structural assemblies to obtain a plurality of characterization samples, respectively detecting each characterization sample according to a preset detection approach to obtain failure analysis information of the TFT-LCD screen, which can accurately detect the failure mechanism of the edge white type mura TFT-LCD display.

Description

Technical Field

[0001] This invention relates to the field of defect detection technology, and more specifically, to a method and system for analyzing samples of TFT-LCD screens with edge-whitening and distorted appearance. Background Technology

[0002] TFT-LCD displays are widely used in automotive instruments and industrial control terminals. After long-term use in humid and hot environments with temperatures of 40 ℃ and humidity of >80%, they are prone to developing edge-whitening and screen distortion. Existing sample preparation techniques often involve violent disassembly and solvent cleaning, which can easily damage the main structure of the screen and the backlight module components. This can lead to the shedding of abnormal deposits and deformation of the screen's optical components, making it impossible to preserve the complete original state of the screen and backlight module. Consequently, the failure mechanism is misjudged, and product optimization lacks real data support. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a method and system for sample preparation and analysis of edge-whitening screen distortion in TFT-LCD screens, so as to accurately detect the failure mechanism of TFT-LCD displays with edge-whitening screen distortion.

[0004] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions: According to one aspect of the present invention, a method for sample preparation and analysis of edge-whitening screen distortion in TFT-LCD screens is provided, comprising: Dust-free, dry compressed air is used to remove surface dust from the TFT-LCD screen; An ultrasonic cutter is used to cut along the screen bezel of the TFT-LCD screen to separate the TFT-LCD screen housing from the main body; The main body of the TFT-LCD screen is separated step by step to obtain several structural components; Several characterization samples were obtained by partitioning and cutting the abnormal areas of the upper polarizer, flexible printed circuit board, and reflective sheet in the structural components. Each of the characterization samples was tested according to the preset detection method to obtain failure analysis information of the TFT-LCD screen.

[0005] According to another aspect of the present invention, a sample analysis system for edge-whitening distortion of a TFT-LCD screen is provided, employing the sample analysis method for edge-whitening distortion of a TFT-LCD screen as described in the first aspect, comprising: The dust removal module is used to remove surface dust from the TFT-LCD screen using dust-free, dry compressed air. The cutting module is used to perform ultrasonic cutting along the screen bezel of the TFT-LCD screen to separate the housing and body of the TFT-LCD screen. The separation module is used to perform step-by-step separation of the main body of the TFT-LCD screen to obtain several structural components; The cutting module is used to cut out abnormal areas of the upper polarizer, flexible printed circuit board and reflective sheet in the structural components to obtain several characterization samples. The detection module is used to detect each of the characterization samples according to a preset detection method to obtain failure analysis information of the TFT-LCD screen.

[0006] As can be seen from the above technical solution, the TFT-LCD screen edge whitening and screen distortion sample preparation and analysis method provided by the present invention has the following beneficial effects: This invention provides complete protection for the main screen and all components of the backlight module, without structural damage, deformation, or detachment of adhering substances. It utilizes ultrasonic scalpel non-destructive cutting, dust-free and dry compressed air cleaning, and solvent-free processes, eliminating external contamination and secondary damage. The standardized sample preparation fully preserves the original characteristics of the failure and allows for simultaneous and accurate identification of characteristic products such as basic copper carbonate and potassium iodide. Based on the test results of the complete screen and backlight module, it provides a reliable basis for optimizing sealing processes and the weather resistance of polarizers. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort: Figure 1 This is a schematic diagram illustrating the steps of the sample preparation and analysis method for a TFT-LCD screen with edge whitening and distorted appearance provided in an embodiment of the present invention; Figure 2 A schematic diagram illustrating a specific implementation process of a step in the sample preparation and analysis method for edge-whitening and distorted screen patterns of a TFT-LCD screen provided in this embodiment of the invention; Figure 3 A schematic diagram illustrating another step in the sample preparation and analysis method for edge-whitening and distorted screen patterns of TFT-LCD screens provided in this embodiment of the invention; Figure 4 A schematic diagram illustrating another step in the sample preparation and analysis method for edge-whitening and distorted screen patterns of TFT-LCD screens provided in this embodiment of the invention; Figure 5 This is a schematic diagram of the TFT-LCD screen edge whitening type screen sample preparation and analysis device provided in an embodiment of the present invention; Figure 6The FTIR spectrum of the upper polarizer component in the sample preparation and analysis method for edge-whitening screen distortion of TFT-LCD screen provided in this embodiment of the invention; Figure 7 The FTIR spectrum of green corrosion products in the sample preparation and analysis method for edge-whitening screen distortion of TFT-LCD screens provided in this embodiment of the invention; Figure 8 XPS spectrum of surface green deposits in the sample preparation and analysis method for edge-whitening screen distortion of TFT-LCD screen provided in this embodiment of the invention; Figure 9 XPS spectrum of white crystals on the surface of the reflective sheet in the sample preparation and analysis method for edge-whitening screen distortion of TFT-LCD screen provided in the embodiments of the present invention. Detailed Implementation

[0008] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0009] This invention provides a method for sample preparation and analysis of edge-whitening and distorted screen patterns on TFT-LCD screens, the steps of which are as follows: Figure 1 As shown, it includes: The first step is to use dust-free, dry compressed air to remove surface dust from the TFT-LCD screen.

[0010] Specifically, in the first step of the embodiment provided by the present invention, a special dust-free dry compressed air supply device is used to ensure that the compressed air has undergone effective filtration and drying to remove impurities such as dust particles, moisture and oil. Generally speaking, the cleanliness of the compressed air should meet a certain standard, such as the relevant level specified in ISO 8573-1, to ensure that it will not cause secondary pollution to the screen.

[0011] More specifically, maintain an appropriate distance (usually 10-20 cm) and angle (usually 45°-90°) between the compressed air spray gun or nozzle and the TFT-LCD screen, and blow evenly on the screen surface. During operation, the spray gun should be moved slowly along the screen surface to ensure that the entire screen surface is effectively cleaned. The pressure of the compressed air should be reasonably controlled according to the material and structure of the screen. Generally speaking, the pressure should not be too high to avoid damaging the screen, and is usually controlled between 0.2-0.5 MPa.

[0012] More specifically, dust on the surface of a TFT-LCD screen can enter the screen during subsequent cutting and separation operations, affecting the separation and observation of various components and even causing deviations in test results. For example, when using an ultrasonic cutter to cut the screen frame, dust can enter the screen body during the cutting process, interfering with the analysis of the internal structure.

[0013] More specifically, when inspecting the various components of the screen, surface dust can obscure the true condition of the component surface, affecting the identification and analysis of abnormal areas. For example, when using a super depth-of-field digital microscope to observe the pixel arrangement and structural wrinkles of the upper polarizer on the screen, dust can make the observation results blurry, making it impossible to accurately determine whether the pixel arrangement is normal or whether there are structural wrinkles or other problems.

[0014] More specifically, if surface dust is not removed first, it will rub against the screen surface during subsequent operations, scratching the screen and further aggravating its damage. Using dust-free, dry compressed air to blow away dust effectively removes it without contacting the screen surface, preventing mechanical damage.

[0015] The second step involves using an ultrasonic cutter to cut along the screen bezel of the TFT-LCD screen, separating the casing and the main body of the TFT-LCD screen.

[0016] Specifically, in the second step of the embodiment provided by the present invention, a suitable ultrasonic scalpel device is selected to ensure that its power and cutting speed can meet the cutting requirements. In one embodiment, the cutting parameters of the ultrasonic scalpel are a power of 20-30W and a speed of 5-10mm / S. The ultrasonic scalpel is adjusted and calibrated, and the various functions of the device are checked to ensure the stability and accuracy of the cutting process.

[0017] More specifically, place the TFT-LCD screen on a suitable workbench and use clamps or other fixing devices to firmly secure the screen to prevent it from moving or shaking during the cutting process, which would affect the cutting effect. Determine the cutting path, generally cutting along the screen border of the TFT-LCD screen. A marking tool can be used to mark the cutting line on the screen border to ensure the accuracy of the cutting.

[0018] More specifically, start the ultrasonic cutter and cut along the marked cutting line according to the preset cutting parameters. During the cutting process, maintain a uniform and stable cutting speed to avoid cutting too fast or too slow. Closely observe the cutting process to ensure that the cutting depth is appropriate, so as to effectively separate the shell and the main body without damaging the internal structure of the screen.

[0019] More specifically, after cutting, carefully separate the shell and the main body to avoid causing additional damage to the screen, and clean the cut edges to remove any remaining debris and impurities.

[0020] More specifically, the casing of a TFT-LCD screen typically serves to protect and secure the internal main structure. By cutting the screen bezel to separate the casing from the main body, the internal main structure can be exposed, facilitating subsequent step-by-step separation of the main structure to obtain each structural component. This allows for further testing and analysis of these components, identifying the cause of the screen edge whitening / flawed screen failure.

[0021] More specifically, ultrasonic cutters have advantages such as high cutting precision and low heat-affected zone. Using an ultrasonic cutter to cut along the screen edge can separate the shell and the main body while minimizing damage to the internal structure of the screen. Compared with other cutting methods, such as mechanical cutting, ultrasonic cutters can better control the cutting process and avoid secondary damage to the electronic components and structure inside the screen caused by excessive cutting force or heat generated during the cutting process.

[0022] The third step involves separating the main body of the TFT-LCD screen step by step to obtain several structural components.

[0023] Specifically, in the third step of the embodiment provided by the present invention, the upper polarizer, the TFT-LCD functional layer, the lower polarizer, the backlight module, and the metal frame are separated in that order. Then, the backlight module is disassembled again to obtain the flexible printed circuit board and the reflective sheet. This order is determined based on the structural characteristics of the TFT-LCD screen and the principle of ease of operation.

[0024] More specifically, using specialized tools such as a flat plastic scraper or tweezers, carefully start from the edge of the screen body. The surface of the upper polarizer is covered with a protective film. Use the tweezers to peel off the protective film on the surface of the white area. At this time, the upper polarizer will be fully exposed. Along the joint between the upper polarizer and other structures, slowly and gently peel off the upper polarizer. During the operation, avoid using too much force to prevent the upper polarizer from cracking or being damaged.

[0025] More specifically, after removing the upper polarizer, the TFT-LCD functional layer will be exposed. You can use appropriate tools, such as a small screwdriver or pry bar, to gently pry the connection between the TFT-LCD functional layer and the adjacent structure to gradually separate them. When doing so, be careful to avoid damaging the electronic components on the functional layer.

[0026] More specifically, similar to separating the upper polarizer, use a flat tool to carefully peel the lower polarizer off the screen body, starting from the edge. The lower polarizer is more tightly attached to other structures, requiring more patience and meticulous operation.

[0027] More specifically, the backlight module is removed from the screen body by removing the screws or clips that secure it. During the removal process, be sure to record the location and number of screws for later reassembly.

[0028] More specifically, use a screwdriver or similar tool to remove the screws securing the metal frame, and then carefully remove the metal frame from the screen body.

[0029] More specifically, open the backlight module's casing, locate the connection point between the flexible printed circuit board and the reflector, and use appropriate tools to separate them from the backlight module.

[0030] More specifically, the whitening or distorted appearance at the edges of a TFT-LCD screen is caused by problems with different structural components. By separating the main body of the screen into its individual components, each component can be tested and analyzed separately. This allows for a more targeted identification of potentially problematic components. Separating them in a specific order can minimize the risk of damage to other components. The fourth step involves partitioning and cutting the abnormal areas of the upper polarizer, flexible printed circuit board, and reflector in the structural components to obtain several characterization samples.

[0031] Specifically, in the fourth step of the embodiment provided by the present invention, the upper polarizer is carefully observed to identify the white area as an anomaly identification information. This can be done under good lighting conditions by direct observation with the naked eye, or with the assistance of tools such as a magnifying glass. The obvious white area is marked. The flexible printed circuit board is inspected to find the green attachment area as an anomaly identification information. More detailed observation is required using equipment such as a microscope to determine the specific location and range of the green attachment. The reflective sheet is observed to identify the white crystalline area as an anomaly identification information. This can also be done by direct observation under suitable lighting conditions, or by confirmation using tools such as a microscope.

[0032] More specifically, based on preset cutting standards, marking tools (such as markers) are used to delineate the areas corresponding to the abnormal identification information on the upper polarizer, flexible printed circuit board, and reflective sheet to determine the cutting target area. For the upper polarizer, the cutting target area is delineated to a size of 5mm × 5mm; for the flexible printed circuit board and reflective sheet, the cutting target area is delineated to a size of 3mm × 3mm. A graduated template or measuring tool can be used to assist in the delineation to ensure the accuracy of the dimensions.

[0033] More specifically, an ultrasonic scalpel is used to cut the designated cutting target area. Before cutting, it is necessary to ensure that the structural components are firmly fixed to avoid movement during the cutting process. The ultrasonic scalpel is operated according to the preset cutting parameters (such as power, speed, etc.) to cut along the marked cutting target area edge to obtain several characterization samples. During the cutting process, the cutting should be kept stable and accurate to avoid cutting into non-target areas.

[0034] More specifically, the whitening or distorted screen problem at the edges of TFT-LCD screens is usually caused by anomalies in specific areas. By identifying and cropping the abnormal areas, the focus of the analysis can be concentrated on the parts that may have problems, improving the targeting and efficiency of the analysis.

[0035] More specifically, cutting abnormal areas into characterization samples of appropriate size facilitates subsequent analysis using various detection methods. Smaller sample sizes can better adapt to the requirements of different detection equipment, improving the accuracy and reliability of detection. For example, detection equipment such as ultra-depth-of-field digital microscopes, scanning electron microscopes, Fourier transform micro-infrared spectroscopy, and X-ray photoelectron spectroscopy have certain requirements for sample size, and samples of appropriate size can be more convenient for detection operations.

[0036] The fifth step involves testing each of the characterization samples according to the preset detection method to obtain failure analysis information of the TFT-LCD screen.

[0037] Specifically, in the fifth step of the embodiment provided by the present invention, the characterization sample of the upper polarizer is placed on the stage of the super depth-of-field digital microscope, and the focal length, magnification and other parameters of the microscope are adjusted so that the pixel arrangement of the screen and the structural wrinkles of the upper polarizer can be clearly observed. The observation results are recorded by the image acquisition system of the microscope to obtain the first detection data. According to the characteristics of the sample and the observation requirements, an appropriate magnification is selected. Generally, it can be gradually adjusted from low magnification to high magnification to fully observe the pixel arrangement and structural wrinkles.

[0038] More specifically, the characterization samples of flexible printed circuit boards and reflective sheets were fixed on the sample stage using conductive adhesive. Vacuum sputtering technology was then used to perform vacuum sputtering treatment on the fixed samples with a sputtering current of 10 mA and a sputtering time of 60 s to improve the conductivity of the samples. The treated samples were then placed in the sample chamber of a scanning electron microscope, and the microscope parameters, such as acceleration voltage and scanning speed, were adjusted to observe the microscopic morphology of the deposits and crystals on the samples. The observation results were recorded to obtain the second detection data.

[0039] More specifically, the characterization samples, including the upper polarizer, flexible printed circuit board, and reflector, were placed directly in the detection area of ​​the Fourier transform micro-infrared spectrometer, and the detection was performed according to the instrument's operating instructions, with the spectral data recorded.

[0040] More specifically, Fourier transform micro-infrared spectrometers record spectral data, and information on the functional groups of anomalous substances is obtained by analyzing the spectral data, which is the third detection data.

[0041] More specifically, the characterization samples of the upper polarizer, flexible printed circuit board, and reflector were placed in the sample chamber of the X-ray photoelectron spectrometer, and the elemental and chemical states of the crystals were detected according to the instrument's operating procedure. The detection results were recorded to obtain the fourth detection data.

[0042] More specifically, the first, second, third, and fourth test data are comprehensively analyzed. By combining the information reflected by each test data, such as pixel arrangement, microstructure, functional groups, elements and chemical states, the cause of the whitening-type screen distortion at the edge of the TFT-LCD screen is determined, thereby obtaining the failure analysis information of the TFT-LCD screen.

[0043] More specifically, the top polarizer, flexible printed circuit board, and reflector are key components in TFT-LCD screens related to display and backlight. Targeted testing of characterization samples of these components can accurately identify the causes of screen edge whitening or flickering problems. For example, structural abnormalities in the top polarizer can affect the polarization and transmission of light, leading to abnormal screen display; contaminants or crystal growth on the flexible printed circuit board can affect signal transmission; and abnormalities in the reflector can affect the reflection and distribution of backlight, resulting in uneven screen brightness or whitening.

[0044] Furthermore, the cutting parameters of the ultrasonic scalpel are: power 20-30W, speed 5-10mm / S.

[0045] Specifically, before using an ultrasonic scalpel for cutting, the cutting parameters need to be accurately set. Through the control panel of the ultrasonic scalpel device, adjust the power to the range of 20-30W and set the cutting speed to 5-10mm / s.

[0046] More specifically, the power setting between 20 and 30W is to provide sufficient energy to cut the screen bezel without causing excessive damage to the internal structure of the screen due to excessive power. If the power is too low, the screen bezel cannot be cut effectively, resulting in incomplete cutting or a slow cutting speed; while if the power is too high, it will generate too much heat, damaging the electronic components and structure inside the screen and affecting subsequent analysis and testing.

[0047] More specifically, setting the cutting speed to 5-10mm / s ensures a smooth and continuous cutting process. Excessive speed can result in uneven cut edges and may even cause significant impact between the cutting head and the screen frame, damaging the screen. Conversely, too slow a speed increases cutting time, reduces work efficiency, and can also generate excessive heat due to the cutting head remaining in the same position for too long, potentially damaging the screen.

[0048] Furthermore, the sequence of separating the main body of the TFT-LCD screen is as follows: upper polarizer, TFT-LCD functional layer, lower polarizer, backlight module, and metal frame; the backlight module is then disassembled again to obtain a flexible printed circuit board and a reflective sheet.

[0049] Specifically, prepare tools such as a flat plastic scraper and tweezers. Starting from the edge of the screen, carefully insert the flat plastic scraper or tweezers into the area where the upper polarizer is attached to the adjacent structure. Slowly move the tool along the attachment surface to gradually lift the upper polarizer. The operation should be gentle to avoid breaking the upper polarizer.

[0050] More specifically, to separate the TFT-LCD functional layer, prepare tools such as a small screwdriver and a pry bar. After removing the upper polarizer, carefully remove the screws (if any) that secure the TFT-LCD functional layer to other structures using a small screwdriver. Then, gently pry the connection between the TFT-LCD functional layer and the adjacent structure with a pry bar to gradually separate them. Take care to avoid damaging the electronic components on the functional layer during the operation.

[0051] More specifically, to separate the lower polarizer, use the same tools as to separate the upper polarizer. Similar to the method used to separate the upper polarizer, start from the edge and carefully peel the lower polarizer off the screen body with the help of the tools. Since the lower polarizer is attached to other structures more tightly, you need to be more patient and meticulous.

[0052] More specifically, separate the backlight module by using a screwdriver to remove the screws or clips securing it, and then carefully remove the backlight module from the screen body. Note the location and number of screws for later reassembly.

[0053] More specifically, separate the metal frame by removing the screws securing it with a screwdriver, and then remove the metal frame from the screen body.

[0054] More specifically, disassemble the backlight module to obtain the flexible printed circuit board and reflector. Open the backlight module's casing, locate the connection point between the flexible printed circuit board and the reflector, remove the relevant screws with a screwdriver, and carefully separate the flexible printed circuit board and the reflector with tweezers.

[0055] More specifically, the structure of a TFT-LCD screen is hierarchical. The upper polarizer is located on the top layer and is in direct contact with the outside world. Separating it first will not affect the separation of other structures. Next, the TFT-LCD functional layer is separated. It is adjacent to the upper polarizer and relatively independent. Then comes the lower polarizer, and then the backlight module and the metal frame. This order conforms to the structural characteristics of the screen from the outside to the inside and from easy to difficult, which is convenient for operation.

[0056] Furthermore, such as Figure 2 As shown, the steps for partitioning and cutting abnormal areas in the upper polarizer, flexible printed circuit board, and reflector in the structural components to obtain several characterization samples include: S41: Identify abnormal conditions in the upper polarizer, flexible printed circuit board, and reflector to obtain abnormal identification information; S42: Delineate the range of the abnormal identification information according to the preset cutting standard, so as to delineate the cutting target area on the upper polarizer, flexible printed circuit board and reflective sheet; S43: The target area is cut using an ultrasonic scalpel to obtain several characterization samples.

[0057] Specifically, place the upper polarizer in a uniform and soft lighting environment. A white background can be used to enhance the clarity of observation. Observe directly with the naked eye, and use a magnifying glass to help identify the white areas. The white areas are usually lighter in color than the normal areas, appearing as obvious white or grayish-white.

[0058] Furthermore, the abnormal identification information of the upper polarizer is a white area, the abnormal identification information of the flexible printed circuit board is a green adhesion area, and the abnormal identification information of the reflective sheet is a white crystalline area.

[0059] Furthermore, the size of the cutting target area of ​​the upper polarizer is 5mm×5mm, and the size of the cutting target area of ​​the flexible printed circuit board and the reflective sheet is 3mm×3mm.

[0060] More specifically, carefully observe the surface of the circuit board to identify green adhesion areas, which are caused by corrosion, pollution, or chemical reactions.

[0061] More specifically, observe the reflective sheet under strong light, ensuring the light shines evenly on its surface, and identify the white crystalline areas. The white crystals are formed due to factors such as water evaporation and substance precipitation.

[0062] More specifically, according to the preset cutting standards, the target cutting area size of the upper polarizer is 5mm×5mm, and the target cutting area size of the flexible printed circuit board and the reflective sheet is 3mm×3mm. Using a marker or special marking sticker, mark the boundaries of abnormal areas on the upper polarizer, flexible printed circuit board, and reflective sheet. Use graduated measuring tools, such as rulers or calipers, to ensure that the marked areas meet the preset size requirements.

[0063] More specifically, adjust the ultrasonic scalpel device to normal working condition, set appropriate cutting parameters, such as power 20-30W and speed 5-10mm / S, fix the marked upper polarizer, flexible printed circuit board and reflector on the cutting worktable to ensure that the sample will not move during the cutting process, start the ultrasonic scalpel and cut according to the marked cutting target area edge, keep the cutting head moving stably during the cutting process to ensure the accuracy and integrity of the cutting.

[0064] More specifically, the whitening or distorted screen at the edge of a TFT-LCD screen is caused by an anomaly in a specific area. By identifying the abnormal area, the analysis can focus on the potentially problematic parts, avoiding unnecessary testing of the entire component and improving analysis efficiency.

[0065] More specifically, the preset cutting standard can ensure that the cutting size of different samples is consistent, which is convenient for subsequent testing and comparison. The uniform size is also conducive to the operation of the testing equipment and data processing. Cutting the abnormal area can reduce the interference of the normal area on the test results, so that the test results can more accurately reflect the situation of the abnormal area.

[0066] More specifically, cutting out the abnormal area to obtain a characterization sample allows it to be easily placed in various testing devices for analysis. The smaller sample size is more suitable for the requirements of the testing devices, improving the accuracy and reliability of the testing. Using an ultrasonic scalpel for cutting can accurately obtain the sample from the abnormal area while minimizing the impact on other areas. The ultrasonic scalpel has high cutting precision and low heat-affected zone, ensuring the integrity and accuracy of the sample.

[0067] refer to Figures 6-9 Furthermore, such as Figure 3 As shown, the steps for obtaining failure analysis information of the TFT-LCD screen by detecting each of the characterization samples according to the preset detection method include: S51: The structural wrinkles of the characterization sample of the upper polarizer are observed by using an ultra-depth-of-field digital microscope, and the pixel arrangement of the TFT-LCD functional layer is observed to obtain the first detection data. S52: The microscopic morphology of the deposits and crystals on the characterization samples of the flexible printed circuit board and the reflective sheet is observed by scanning electron microscopy to obtain the second detection data; S53: The material composition and abnormal substance functional groups of the characterization samples of the upper polarizer, the flexible printed circuit board and the reflective sheet are analyzed by Fourier transform micro-infrared spectroscopy to obtain the third detection data. S54: The characterization samples of the upper polarizer, the flexible printed circuit board, and the reflective sheet are analyzed by X-ray photoelectron spectroscopy to detect the crystalline elements and chemical states, and the fourth detection data is obtained. S55: Perform an overall analysis of the first detection data, the second detection data, the third detection data, and the fourth detection data to obtain failure analysis information of the TFT-LCD screen.

[0068] Specifically, the characterization sample with the upper polarizer is placed stably on the stage of the ultra-depth-of-field digital microscope, ensuring the sample is well fixed and avoiding movement during observation. The magnification of the microscope is adjusted, starting from a low magnification and gradually increasing to a suitable magnification for observing pixel arrangement and structural wrinkles (e.g., 50-200 times). At the same time, parameters such as focal length and light intensity are adjusted to make the image clear. The structure is observed for any abnormalities such as wrinkles or bends. The observed images and related data are recorded using an image acquisition system. Simultaneously, the pixel arrangement of the upper polarizer is observed through the microscope eyepiece or a connected imaging device to detect problems such as missing pixels or disordered arrangement. At the same time, the screen pixel arrangement of the TFT-LCD functional layer is observed to obtain the first detection data.

[0069] More specifically, the pixel arrangement of the upper polarizer directly affects the display effect of the screen. Abnormal pixel arrangement, such as missing or disordered pixels, can cause phenomena such as whitening or screen distortion. These problems can be directly observed using a super depth-of-field digital microscope, providing basic information for analyzing the cause of screen failure. Structural wrinkles in the upper polarizer can damage its optical performance, change the propagation and polarization characteristics of light, and thus affect the normal display of the screen. Observing the structural wrinkles helps to determine whether the screen display failure is caused by changes in the physical structure of the upper polarizer.

[0070] More specifically, the flexible printed circuit board and reflective sheet characterization samples were fixed on the sample stage using conductive adhesive. The fixed samples were then treated with vacuum sputtering gold technology, with the sputtering current set to 10 mA and the sputtering time set to 60 s to improve the conductivity of the samples. The treated samples were then placed in the sample chamber of a scanning electron microscope, the sample chamber door was closed and a vacuum was drawn, and appropriate parameters such as the accelerating voltage (e.g., 5-20 kV) and working distance were set. The sample surface was observed on the display screen to look for attached foreign matter and grown crystals, and their shape, size, distribution and other microscopic morphological characteristics were recorded to obtain the second detection data.

[0071] More specifically, the deposits on the surface of flexible printed circuit boards and reflective sheets may be impurities, contaminants, or chemical reaction products. These deposits can affect the electrical performance of the circuit board and the optical performance of the reflective sheet, thus causing abnormal screen display. These tiny deposits can be clearly seen through high-resolution observation using a scanning electron microscope.

[0072] More specifically, the abnormal area on the sample surface is precisely located under the microscope imaging field to determine the location of the micro-region of the foreign object to be tested. A sterile scalpel tip is used to micro-peel and pick up the target foreign object located under the microscope, separating it into an independent micron-sized foreign object sample. The collected micro-foreign object is carefully transferred to an infrared transparent barium fluoride window substrate, flattened, and then aligned with the foreign object micro-region again through the microscope optical path. Subsequently, a micro-transmission sampling method is used, with an infrared beam perpendicularly incident and penetrating the foreign object micro-region to collect micro-transmission infrared spectral data. The instrument's scanning range, number of scans, and other parameters are set (e.g., scanning range 4000 - 700 cm⁻¹). - ¹ (32 scans) were performed to collect the infrared spectrum of the sample. The spectrum was analyzed to identify the functional groups of the abnormal substances and obtain the third detection data.

[0073] More specifically, the functional group information of anomalous substances can reflect their chemical composition and structure. By analyzing the functional groups, the type of anomalous substance can be determined, whether it is an organic or inorganic substance, and its possible source can be identified.

[0074] More specifically, the characterization samples, including the upper polarizer, flexible printed circuit board, and reflector, are placed in the analysis chamber of the X-ray photoelectron spectrometer. The vacuum level required for the instrument to operate is evacuated, and the sample surface is irradiated with X-rays to excite electrons in the sample. The energy of the electrons is measured by an energy analyzer to obtain a photoelectron spectrum. The spectrum is then analyzed to determine the types of elements and their chemical states contained in the crystals, thus obtaining the fourth detection data.

[0075] More specifically, the elemental composition of crystals is crucial information for understanding their properties and origins. X-ray photoelectron spectroscopy can accurately determine the types of elements contained in crystals and identify any abnormal elements, such as metal contamination. The chemical state of an element reflects its form of existence and chemical environment in the substance. Different chemical states are associated with different chemical reactions and failure mechanisms. For example, different oxidation states of metal elements are related to the corrosion process of materials. Analyzing the chemical state of elements helps to gain a deeper understanding of the chemical processes of screen failure.

[0076] More specifically, the first, second, third, and fourth detection data are compiled, including images, spectra, elemental analysis results, etc., to ensure the accuracy and completeness of the data. The data are then combined for comprehensive analysis. For example, if the first detection data shows abnormal pixel arrangement of the upper polarizer, and the third detection data indicates the presence of abnormal substances with specific functional groups, it is speculated that this substance affects the pixel arrangement and causes the screen problem. By correlating and verifying the different detection data, the cause of the whitening screen at the edge of the TFT-LCD screen can be found, and failure analysis information can be obtained.

[0077] More specifically, preliminary data identification is performed on the first, second, third, and fourth detection data to obtain the corresponding first, second, third, and fourth data features. Based on each data feature, the observation status of each component of the screen is analyzed to generate observation status information of each component. Then, the correlation analysis of the observation status information of each component is performed to score several possible failure processes of the screen as a whole, and select several possible failure processes that meet the preset criteria.

[0078] More specifically, based on the selected failure process, evidence is collected from the first, second, third, and fourth detection data. Positive data that can prove the failure process and negative data that can refute the failure process are found among the four data items. An evidence list for each failure process is generated. Based on the evidence list, each failure process is decomposed into several time-series units. Each time-series unit is optimized according to the evidence list to obtain the theoretical failure change process of the TFT-LCD screen.

[0079] Furthermore, before performing scanning electron microscopy, the flexible printed circuit board and the reflective sheet are fixed with conductive adhesive, and the fixed flexible printed circuit board and the reflective sheet are subjected to vacuum sputtering treatment with a sputtering current of 10 mA and a sputtering time of 60 s using vacuum sputtering technology.

[0080] Specifically, prepare conductive adhesive of appropriate size, ensure that the conductive adhesive is within its expiration date and in good condition, place the characterization samples of flexible printed circuit boards and reflective sheets on a clean and flat sample stage, check whether there is dust or impurities on the sample surface, and if so, gently wipe it clean with a lint-free cloth.

[0081] Place the sample stage, with the sample secured, into the sample chamber of the vacuum gold spraying equipment. Ensure the sample stage is stable to prevent movement during the spraying process. Close the sample chamber door and activate the vacuum system to evacuate the sample chamber to a vacuum level, typically 10. - ² - 10 - ³ Pa, to ensure that metal particles can be successfully deposited on the sample surface during the gold spraying process.

[0082] More specifically, set the sputtering current to 10 mA and the gold spraying time to 60 s on the equipment control panel. Different gold spraying devices may have slightly different operating interfaces, but all can be adjusted using the corresponding parameter setting buttons. Once the gold spraying program is started, the equipment will generate gold particles from the gold target under the action of the sputtering current, which will then be deposited on the sample surface. During the gold spraying process, it is crucial to closely monitor the equipment's operating status and parameter changes to ensure the process proceeds normally.

[0083] More specifically, the equipment will automatically stop gold spraying after 60 seconds. After the sample chamber returns to normal pressure, the sample chamber door is opened, the gold-sprayed sample is removed, and it is ready for scanning electron microscopy (SEM) analysis.

[0084] More specifically, during scanning electron microscopy, the electron beam scans the sample. If the sample is not securely fixed, it is prone to movement, resulting in blurred images and an inability to accurately observe the sample's microstructure. Using conductive adhesive to firmly fix the sample on the sample stage can ensure the stability of the sample position during the detection process and improve the accuracy of the detection results.

[0085] More specifically, flexible printed circuit boards and reflective sheets are prone to charge accumulation under electron beam bombardment, affecting image quality. Vacuum sputtering gold deposition of a gold film on the sample surface can significantly improve the conductivity of the sample, allowing electrons to conduct smoothly on the sample surface and reducing interference caused by charge accumulation. Scanning electron microscopes mainly image by detecting secondary electrons emitted from the sample surface. Gold has excellent secondary electron emission properties. Sputtering gold can increase the secondary electron emission rate of the sample surface, making the detected secondary electron signal stronger, thereby improving image contrast and clarity, and allowing for clearer observation of the sample's microstructure.

[0086] Furthermore, such as Figure 4 As shown, the detection methods of Fourier transform micro-infrared spectrometer include: S531: Locate the surface anomalous region of the characterization sample by using the imaging field of a Fourier transform micro-infrared spectrometer, so as to determine the region of the foreign object to be tested on the characterization sample. S532: Using a sterile surgical scalpel tip or micro-needle, a specified amount of foreign matter is peeled off and sampled from the area to be tested, so as to separate an independent micron-sized foreign matter sample; S533: The isolated micron-sized foreign matter samples collected by stripping are transferred to a transparent barium fluoride window substrate and flattened to obtain the foreign matter sample; S534: The microscope optical path of the Fourier transform micro-infrared spectrometer is aligned with the foreign object sample, and the infrared beam is driven to be perpendicularly incident and penetrate the foreign object sample by using the micro-transmission sampling method to collect the third detection data in the form of micro-transmission infrared spectral data.

[0087] Specifically, the Fourier transform infrared microscopy instrument is turned on, and the imaging field of view is adjusted to cover the surface of the sample. By observing the image features in the imaging field of view, abnormal areas on the surface are identified. This involves adjusting parameters such as image contrast and brightness to more clearly observe features that are different from normal areas. The instrument's built-in image analysis software can be used to analyze the area within the imaging field of view, mark abnormal areas, and thus determine the area of ​​the foreign object to be tested on the sample.

[0088] More specifically, Fourier transform infrared microscopy can provide image information of the sample surface. Different substances will exhibit different characteristics in infrared imaging. Abnormal areas on the surface may be caused by the presence of foreign objects. By locating these abnormal areas, the location of the foreign object to be tested can be accurately determined, providing a target for subsequent sampling and analysis, avoiding aimless detection of the entire sample, and improving detection efficiency and accuracy.

[0089] More specifically, using a sterile scalpel tip or microneedle, under the observation of a microscope, carefully approach the area of ​​the foreign object to be tested, and precisely peel off and pick up the foreign object according to the amount of foreign object to be analyzed. During the operation, try to avoid damaging the surrounding normal sample area, and ensure that the picked foreign object is independent and uncontaminated. After picking, carefully separate the foreign object from the sample surface to obtain an independent micron-sized foreign object sample.

[0090] More specifically, in order to accurately analyze the composition of foreign matter, it is necessary to separate the foreign matter from the sample surface to form an independent sample. The tip of a sterile scalpel or microneedle has the precision to peel off and pick up foreign matter at the micron scale, which can ensure the purity and representativeness of the sample. An independent micron-sized foreign matter sample can avoid interference with the surrounding normal sample, so that the subsequent analysis results can more accurately reflect the true composition of the foreign matter.

[0091] More specifically, the selected individual micron-sized foreign matter samples are carefully transferred onto a transparent barium fluoride window substrate. Micromanipulation tools, such as micropipettes or special tweezers, can be used to place the foreign matter on the window. Then, appropriate tools (such as microneedles) are used to flatten and arrange the foreign matter so that it is evenly distributed on the window to form a flat sample layer.

[0092] More specifically, the transparent barium fluoride window has good infrared transmittance, which can ensure that the infrared beam can pass through the sample smoothly. Transferring the foreign sample onto the window and flattening it helps the infrared beam to pass through the sample evenly, improving the quality of infrared spectral data acquisition. The flat sample layer can reduce the non-uniformity of scattering and absorption, so that the acquired spectral data can more accurately reflect the chemical structure and composition information of the foreign substance.

[0093] More specifically, by adjusting the microscope optical path of the Fourier transform micro-infrared spectrometer to accurately align it with the foreign sample, the instrument's microscopic transmission sampling mode is activated, driving the infrared beam to be perpendicularly incident on the foreign sample. After the infrared beam penetrates the foreign sample, it is received by the detector. The instrument automatically collects and records the infrared spectral data after penetrating the sample. During the acquisition process, it may be necessary to adjust the instrument parameters, such as the number of scans and resolution, according to the characteristics of the sample and experimental requirements, in order to obtain high-quality spectral data.

[0094] More specifically, microscopic transmission sampling can directly obtain the absorption information of foreign samples in the infrared band. Infrared spectroscopy can reflect the vibration and rotation information of molecules. Different chemical functional groups have characteristic absorption peaks in specific infrared bands. By collecting microscopic transmission infrared spectral data, the chemical functional groups and chemical bonds contained in the foreign matter can be analyzed, thereby determining the chemical composition and structure of the foreign matter, providing an important basis for further research and identification. The perpendicularly incident infrared beam can ensure the accuracy and repeatability of spectral data and reduce errors caused by factors such as the incident angle.

[0095] The technical content of the TFT-LCD screen edge whitening and screen distortion sample preparation and analysis method described in the above-disclosed embodiments is as follows: Figure 5 As shown, the present invention provides a TFT-LCD screen edge whitening and screen distortion sample preparation and analysis system, employing the TFT-LCD screen edge whitening and screen distortion sample preparation and analysis method as described in any one of the first aspects, including: The dust removal module is used to remove surface dust from the TFT-LCD screen using dust-free, dry compressed air. The cutting module is used to perform ultrasonic cutting along the screen bezel of the TFT-LCD screen to separate the housing and body of the TFT-LCD screen. The separation module is used to perform step-by-step separation of the main body of the TFT-LCD screen to obtain several structural components; The cutting module is used to cut out abnormal areas of the upper polarizer, flexible printed circuit board and reflective sheet in the structural components to obtain several characterization samples. The detection module is used to detect each of the characterization samples according to a preset detection method to obtain failure analysis information of the TFT-LCD screen.

[0096] In this embodiment, the specific implementation of each module in the above system embodiment is described in the above method embodiment, and will not be repeated here.

[0097] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0098] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for analyzing samples of TFT-LCD screens with edge-whitening and distorted patterns, characterized in that, include: Dust-free, dry compressed air is used to remove surface dust from the TFT-LCD screen; An ultrasonic cutter is used to cut along the screen bezel of the TFT-LCD screen to separate the TFT-LCD screen housing from the main body; The main body of the TFT-LCD screen is separated step by step to obtain several structural components; Several characterization samples were obtained by partitioning and cutting the abnormal areas of the upper polarizer, flexible printed circuit board, and reflective sheet in the structural components. Each of the characterization samples was tested according to the preset detection method to obtain failure analysis information of the TFT-LCD screen.

2. The method for sample preparation and analysis of edge-whitening screen distortion in TFT-LCD screens as described in claim 1, characterized in that, The cutting parameters of the ultrasonic scalpel are: power 20-30W, speed 5-10mm / S.

3. The method for sample preparation and analysis of edge-whitening screen distortion in TFT-LCD screens as described in claim 1, characterized in that, The sequence of separating the main body of the TFT-LCD screen is as follows: upper polarizer, TFT-LCD functional layer, lower polarizer, backlight module, and metal frame; the backlight module is then disassembled again to obtain a flexible printed circuit board and a reflective sheet.

4. The method for sample preparation and analysis of edge-whitening screen distortion in TFT-LCD screens as described in claim 1, characterized in that, The steps for partitioning and cutting abnormal areas in the upper polarizer, flexible printed circuit board, and reflector in the structural components to obtain several characterization samples include: Abnormal conditions are identified in the upper polarizer, flexible printed circuit board, and reflective sheet to obtain abnormal identification information; The abnormal identification information is delineated according to the preset cutting criteria to define the cutting target area on the upper polarizer, flexible printed circuit board, and reflective sheet. An ultrasonic scalpel was used to cut the target area to obtain several characterization samples.

5. The method for sample preparation and analysis of edge-whitening screen distortion in TFT-LCD screens as described in claim 4, characterized in that, The abnormal identification information of the upper polarizer is a white area, the abnormal identification information of the flexible printed circuit board is a green adhesion area, and the abnormal identification information of the reflective sheet is a white crystalline area.

6. The method for sample preparation and analysis of edge-whitening screen distortion in TFT-LCD screens as described in claim 4, characterized in that, The size of the cutting target area of ​​the upper polarizer is 5mm×5mm, and the size of the cutting target area of ​​the flexible printed circuit board and the reflective sheet is 3mm×3mm.

7. The method for sample preparation and analysis of edge-whitening screen distortion in TFT-LCD screens as described in claim 3, characterized in that, The steps for obtaining failure analysis information of the TFT-LCD screen by detecting each of the characterization samples according to a preset detection method include: The structural wrinkles of the characterization sample of the upper polarizer were observed using an ultra-depth-of-field digital microscope, and the screen pixel arrangement of the TFT-LCD functional layer was observed to obtain the first detection data. The microstructure of the deposits and crystals in the characterization samples of the flexible printed circuit board and the reflective sheet were observed by scanning electron microscopy to obtain the second detection data. The third detection data was obtained by analyzing the abnormal substance functional groups of the characterization samples of the upper polarizer, the flexible printed circuit board, and the reflective sheet using Fourier transform micro-infrared spectroscopy. The characterization samples of the upper polarizer, the flexible printed circuit board, and the reflective sheet were analyzed by X-ray photoelectron spectroscopy to detect the crystalline elements and chemical states, thus obtaining the fourth set of detection data. The first detection data, the second detection data, the third detection data, and the fourth detection data are analyzed as a whole to obtain failure analysis information of the TFT-LCD screen.

8. The method for sample preparation and analysis of edge-whitening screen distortion in TFT-LCD screens as described in claim 7, characterized in that, Before performing scanning electron microscopy, the flexible printed circuit board and the reflective sheet are fixed with conductive adhesive, and the fixed flexible printed circuit board and the reflective sheet are subjected to vacuum sputtering treatment with a sputtering current of 10 mA and a sputtering time of 60 s using vacuum sputtering technology.

9. The method for sample preparation and analysis of edge-whitening screen distortion in TFT-LCD screens as described in claim 7, characterized in that, The detection methods of Fourier transform micro-infrared spectrometers include: The imaging field of a Fourier transform micro-infrared spectrometer is used to locate the surface anomalous regions of the characterization sample, so as to determine the region of the foreign object to be tested on the characterization sample. A sterile surgical scalpel tip or micro-needle is used to peel off and pick up a specified amount of foreign matter from the area to be tested, so as to separate independent micron-sized foreign matter samples. The isolated micron-sized foreign matter samples collected by stripping were transferred onto a transparent barium fluoride window substrate and flattened to obtain the foreign matter samples. By aligning the microscope optical path of the Fourier transform micro-infrared spectrometer with the foreign object sample, and using a micro-transmission sampling method to drive the infrared beam to be perpendicularly incident and penetrate the foreign object sample, a third detection data in the form of micro-transmission infrared spectral data is obtained.

10. A sample preparation and analysis system for TFT-LCD screens with edge-whitening and distorted display characteristics, characterized in that... The method for sample preparation and analysis of edge-whitening and distorted screens of TFT-LCD screens as described in any one of claims 1-9 includes: The dust removal module is used to remove surface dust from the TFT-LCD screen using dust-free, dry compressed air. The cutting module is used to perform ultrasonic cutting along the screen bezel of the TFT-LCD screen to separate the housing and body of the TFT-LCD screen. The separation module is used to perform step-by-step separation of the main body of the TFT-LCD screen to obtain several structural components; The cutting module is used to cut out abnormal areas of the upper polarizer, flexible printed circuit board and reflective sheet in the structural components to obtain several characterization samples. The detection module is used to detect each of the characterization samples according to a preset detection method to obtain failure analysis information of the TFT-LCD screen.

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