Method for improving poor orientation of silk-screen position of internal silk-screen LCD (Liquid Crystal Display) product

Abstract

The invention relates to the technical field of liquid crystal displays, and discloses a method for improving poor orientation of a silk-screen position of an internal silk-screen LCD (Liquid Crystal Display) product, which comprises the following steps of: S1, cleaning and drying a silk-screen surface; s2, strictly controlling the environment temperature and humidity before internal screen printing operation; s3, a 500-mesh BOPP18 wire diameter steel mesh is adopted, and the tension of the steel mesh is controlled; s4, ensuring that the ink height is less than or equal to 5 mu when the ink is subjected to internal silk-screen printing; and S5, the product subjected to silk screen printing is placed in a curing oven to be cured. The method provides necessary conditions for stable orientation of liquid crystal molecules by accurately controlling environmental temperature and humidity and parameters of screen printing equipment in an internal screen printing process, realizes efficient correction of poor orientation of a screen printing area by combining with hot drying treatment, and strictly controls the concentration and the filling rate of a chiral agent S811 by optimizing the process links of screen printing, curing, cleaning, filling and the like, so that the production efficiency of the liquid crystal display screen is improved. And the yield of the internal silk-screen LCD product and the accuracy of liquid crystal orientation are obviously improved.

Description

Technical Field

[0001] The invention relates to the technical field of liquid crystal displays, and in particular to a method for improving poor orientation at a silk-screen printing location of an internal silk-screen LCD product. Background Art

[0002] Liquid crystal display (LCD) is one of the core technologies of modern display and is widely used in consumer electronics, industrial control, automotive electronics and other fields. Traditional LCD products usually use screen printing outside the polarizer or screen printing outside the surface to complete the processing of the display structure. However, under the display conditions of large viewing angles, light leakage often occurs in the screen printing area, which has a significant impact on the display effect. Especially in some high-end display scenarios, high requirements are placed on brightness uniformity and optical consistency. The light leakage problem has become a key factor affecting product competitiveness.

[0003] In order to solve the above problems, the LCD industry has gradually developed an internal screen printing process, which is to transfer the screen printing process to the inside of the LCD for operation. Compared with the external screen printing process, the internal screen printing can effectively improve the light leakage problem under a large viewing angle and improve the optical performance of the display. However, the application of the internal screen printing process has not completely solved all technical problems. During the production process, the abnormal arrangement of liquid crystal molecules in the screen printing area often occurs. This problem not only affects the brightness uniformity of the display, but may also cause display defects such as local blur or color shift.

[0004] The abnormal arrangement of liquid crystal molecules is mainly affected by many factors, such as temperature and humidity fluctuations in the production environment, uneven tension of the steel mesh in the screen printing process, and unstable adhesion of the ink. In addition, after the screen printing is completed, the conditions of subsequent processes such as curing and cleaning operations are not properly controlled, which may further aggravate the defects in the screen printing area. The combined effect of these factors has led to a high defect rate of internal screen printing LCD products during mass production, which directly affects the market competitiveness of the products.

[0005] The above problems are common in the LCD industry, especially in high-end display scenarios that pursue wide viewing angles and high contrast. Therefore, focusing on the internal screen printing process, in-depth research on the factors that affect the arrangement of liquid crystal molecules during the production process, and seeking methods to improve the consistency of liquid crystal molecular orientation are of great significance for improving the optical performance and production yield of LCD products. Summary of the invention

[0006] In view of the deficiencies of the prior art, the present invention provides a method for improving the poor orientation of the silk-screen printing area of ​​the inner silk-screen printing LCD product, which solves the problem of poor orientation of liquid crystal molecules in the silk-screen printing area of ​​the inner silk-screen printing LCD product.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for improving the poor orientation of the silk screen of an internal silk screen printed LCD product, comprising the following steps:

[0008] S1. Clean and dry the screen printing surface;

[0009] S2. Before the internal screen printing operation, the ambient temperature and humidity must be strictly controlled;

[0010] S3, use 500 mesh BOPP18 wire diameter steel mesh to control the tension of the steel mesh;

[0011] S4. When screen printing ink, ensure that the ink height is ≤5μ;

[0012] S5. Place the silk-screened product in a curing oven for curing;

[0013] S6. After curing, use the film removal line to clean the product;

[0014] S7, preparing a chiral agent S811 with a concentration of 0.20-0.26%, and pouring it into the liquid crystal box;

[0015] S8. If the silk-screen area still has poor orientation, improve the orientation by placing the product rack in an oven and drying it.

[0016] Preferably, the ambient temperature and humidity control in step S2 is specifically as follows:

[0017] The temperature is maintained at 23±3℃, the humidity is controlled at 53-58%RH, and the internal screen printing operation can only be carried out after the environmental conditions have been stable for more than 30 minutes.

[0018] Preferably, in step S3, the tension of the steel mesh is controlled at 22-23N, and the equipment is calibrated so that the tension difference between the periphery and the center of the steel mesh does not exceed 1N.

[0019] Preferably, in step S5, the curing temperature is controlled at 160-200° C., and the curing time is 1.5-2.5 hours.

[0020] Preferably, in step S6, the cleaning line speed is set to 2-3 m / min, and the cleaning liquid temperature is controlled within the range of 40-60°C.

[0021] Preferably, the concentration range of the chiral agent S811 in step S7 is further refined as follows:

[0022] When the concentration is 0.20-0.24%, it is used to improve the low orientation defect rate in the liquid crystal box;

[0023] When the concentration is 0.24-0.26%, it is used to improve the liquid crystal cell with high requirements for orientation consistency;

[0024] The perfusion rate of the chiral agent is controlled at 0.1-0.3 ml / s.

[0025] Preferably, during the heat-baking improvement process in step S8, the spacing between the racks of the product in the oven is controlled at 5-10 mm, the heat-baking temperature is set to 100° C., the time is 10-15 min, and after the heat-baking is completed, a polarizing microscope is used to detect whether the orientation deviation angle of the liquid crystal molecules is less than ±1°.

[0026] Preferably, in step S1, the drying temperature is set to 70-80° C., and the drying time is controlled to 10-15 min.

[0027] The present invention provides a method for improving the poor orientation of the screen printing of an internal screen-printed LCD product. It has the following beneficial effects:

[0028] 1. The present invention provides necessary conditions for the stable orientation of liquid crystal molecules by precisely controlling the ambient temperature and humidity of 23±3°C, 53-58%RH and the screen printing equipment during the internal screen printing process, such as the tension of the 500-mesh BOPP18 wire diameter steel mesh controlled at 22-23N and the ink height ≤5μ. This process optimization significantly reduces the problem of poor orientation in the screen printing area caused by environmental fluctuations or improper operation, and provides a guarantee for the optical performance and brightness uniformity of the liquid crystal display.

[0029] 2. The present invention provides an efficient solution for the secondary orientation correction of liquid crystal molecules by implementing a heat baking process at 100°C for 10-15 minutes when the orientation in the silk-screen printing area is poor, and by reasonably setting the rack spacing and uniform heating conditions. This process avoids the cost of complex equipment modification, while ensuring the effective improvement of the poor orientation in the silk-screen printing area, thereby improving the flexibility and adaptability of the production line.

[0030] 3. The present invention optimizes the production conditions and parameters of the process links such as screen printing, curing, cleaning, and infusion, and greatly improves the yield rate of internal screen-printed LCD products without the need for equipment modification. By strictly controlling the concentration of the chiral agent S811 at 0.20-0.26% and the infusion rate at 0.1-0.3 ml / s, the accuracy of the liquid crystal orientation is guaranteed, thereby effectively reducing the defective rate and meeting the demand for mass production of liquid crystal display screens. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Flow chart of the method of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Please refer to the attached Figure 1 The embodiment of the present invention provides a method for improving poor orientation of the screen printing of an internal screen-printed LCD product, comprising the following steps:

[0034] S1. Clean and dry the screen printing surface;

[0035] S2. Before the internal screen printing operation, the ambient temperature and humidity must be strictly controlled;

[0036] S3, use 500 mesh BOPP18 wire diameter steel mesh to control the tension of the steel mesh;

[0037] S4. When screen printing ink, ensure that the ink height is ≤5μ;

[0038] S5. Place the silk-screened product in a curing oven for curing;

[0039] S6. After curing, use the film removal line to clean the product;

[0040] S7, preparing a chiral agent S811 with a concentration of 0.20-0.26%, and pouring it into the liquid crystal box;

[0041] S8. If the silk-screen area still has poor orientation, improve the orientation by placing the product rack in an oven and drying it.

[0042] The environmental temperature and humidity control in step S2 is specifically as follows:

[0043] The temperature is maintained at 23±3℃, the humidity is controlled at 53-58%RH, and the internal screen printing operation can only be carried out after the environmental conditions have been stable for more than 30 minutes.

[0044] In step S3, the tension of the steel mesh is controlled at 22-23N, and the equipment is calibrated so that the tension difference between the periphery and the center of the steel mesh does not exceed 1N.

[0045] In step S5, the curing temperature is controlled at 160-200° C., and the curing time is 1.5-2.5 hours.

[0046] In step S6, the cleaning line speed is set to 2-3 m / min, and the cleaning liquid temperature is controlled in the range of 40-60°C.

[0047] The concentration range of the chiral agent S811 in step S7 is further refined as follows:

[0048] When the concentration is 0.20-0.24%, it is used to improve the low orientation defect rate in the liquid crystal box;

[0049] When the concentration is 0.24-0.26%, it is used to improve the liquid crystal cell with high requirements for orientation consistency;

[0050] The infusion rate of the chiral agent was controlled at 0.1-0.3 ml / s.

[0051] During the heat-baking improvement process in step S8, the spacing between the racks of the product in the oven is controlled at 5-10 mm, the heat-baking temperature is set to 100° C., and the time is 10-15 minutes. After the heat-baking is completed, a polarizing microscope is used to detect whether the orientation deviation angle of the liquid crystal molecules is less than ±1°.

[0052] In step S1, the drying temperature is set to 70-80°C, and the drying time is controlled to 10-15 minutes.

[0053] Embodiment 1:

[0054] Method steps and implementation process:

[0055] Cleaning and drying (S1): Use deionized water to rinse the screen printing surface to ensure that there are no particles and contaminants; after cleaning, place it in a drying device with the temperature set to 70°C and the drying time set to 10 minutes.

[0056] Ambient temperature and humidity control (S2): Before the internal screen printing operation, the ambient temperature is adjusted to 23°C and the humidity is controlled at 55% for 30 minutes to ensure the stability of the screen printing process.

[0057] Screen printing operation (S3 & S4): Use 500 mesh BOPP18 wire diameter steel mesh, adjust the steel mesh tension to 23N, and the tension difference between the periphery and the center is 0.8N; the ink height is controlled within 5μ to avoid uneven ink layer or accumulation.

[0058] Curing (S5): The product after screen printing is placed in a curing oven for treatment. The temperature is set to 180°C and the curing time is 2 hours to ensure that the ink layer is uniformly cured.

[0059] De-filming and cleaning (S6): Use a cleaning line to remove the film and clean the product. The cleaning line speed is 2m / min and the cleaning liquid temperature is 40°C. After cleaning, ensure that there is no residue in the silk screen area.

[0060] Chiral agent preparation and injection (S7): Chiral agent S811 is prepared with a concentration of 0.24%, and injected into the liquid crystal box evenly at a speed of 0.2 ml / s through an injection device to ensure the consistency of the arrangement of liquid crystal molecules.

[0061] Heat baking treatment (S8): Place the product racks in an oven with a rack spacing of 5 mm, a heat baking temperature of 100° C., and a heat baking time of 10 minutes to correct the orientation of the screen printing area.

[0062] Implementation summary: This embodiment is operated strictly in accordance with the basic parameters of the technical solution in the document. The screen printing surface is cleaned with deionized water, and the drying temperature and time are controlled to eliminate surface particle contamination; at the same time, the ambient temperature and humidity are strictly controlled before the internal screen printing operation (23°C, humidity 55%, stable for 30 minutes), providing suitable environmental conditions for the stable arrangement of liquid crystal molecules. In the screen printing operation, a 500-mesh BOPP18 wire diameter steel mesh is used with a tension of 23N, and the tension difference is controlled within 0.8N to ensure the uniformity and adhesion of the ink. In the subsequent curing stage, the ink layer is fully cured by treating at 180°C for 2 hours, and the film removal and cleaning eliminates the residue. Finally, the arrangement of the liquid crystal molecules is corrected by configuring a chiral agent with a concentration of 0.24% and drying at 100°C for 10 minutes.

[0063] This embodiment is completely based on the technical solution proposed in the document. It significantly improves the phenomenon of poor orientation of liquid crystal molecules by controlling basic process parameters, and provides a stable basic condition for the optical performance of subsequent liquid crystal boxes. This embodiment is suitable for large-scale mass production of ordinary display screens and has good process operability and stability.

[0064] Embodiment 2:

[0065] Method steps and implementation process:

[0066] Cleaning and drying (S1): Use deionized water to rinse the screen printed surface and further treat it with a special cleaning solution at 70°C; after cleaning, place it in a drying device with the drying temperature set to 75°C and the drying time set to 12 minutes to further improve the cleaning effect.

[0067] Ambient temperature and humidity control (S2): Before the internal screen printing operation, the ambient temperature is adjusted to 23.5°C, the humidity is controlled at 56%, and the stabilization time is extended to 35 minutes to reduce the impact of environmental fluctuations on the liquid crystal orientation.

[0068] Screen printing operation (S3 & S4): Use 500 mesh BOPP18 wire diameter steel screen, adjust the steel screen tension to 22.5N, and optimize the tension difference between the periphery and the center to 0.5N to ensure uniformity of screen printing; the ink height is controlled to 4.5μ to further improve the consistency of the ink layer.

[0069] Curing (S5): After the screen printing is completed, the product is placed in a curing oven, the temperature is set to 185°C, and the curing time is extended to 2 hours and 15 minutes to enhance the curing effect of the ink layer.

[0070] De-filming cleaning (S6): The cleaning line speed is increased to 2.5 m / min, and the cleaning liquid temperature is adjusted to 50°C. The cleaning efficiency and surface cleanliness are improved through higher speed and temperature.

[0071] Chiral agent preparation and injection (S7): Chiral agent S811 is prepared, and the concentration is optimized to 0.22%. The injection rate is increased to 0.25 ml / s to ensure that the liquid crystal molecules in the liquid crystal box are more evenly distributed.

[0072] Thermal baking treatment (S8): the product racks are placed in an oven, the rack spacing is optimized to 7 mm, the thermal baking temperature is 102° C., and the thermal baking time is 12 minutes, so as to further improve the orientation consistency of the screen printing area.

[0073] Implementation summary: Based on Example 1, this example optimizes the cleaning, environmental control, screen printing, curing and heat drying links. For example, a special cleaning liquid at 70°C is added during the cleaning stage, the drying temperature is increased to 75°C, and the time is extended to 12 minutes to make the screen printing surface cleaner. Before the internal screen printing operation, the ambient temperature is adjusted to 23.5°C, the humidity is controlled at 56%, and the stabilization time is extended to 35 minutes to further reduce the interference of environmental fluctuations on the liquid crystal orientation. During the screen printing stage, the tension is optimized to 22.5N, the tension difference is reduced to 0.5N, and the ink height is reduced to 4.5μ, which enhances the uniformity and optical consistency of the ink layer. The subsequent curing temperature is increased to 185°C, and the time is extended to 2 hours and 15 minutes to further improve the adhesion performance of the ink layer; the speed and temperature of the film removal cleaning are increased to improve the cleaning efficiency. The concentration of the chiral agent is optimized to 0.22%, and the perfusion rate is increased to 0.25ml / s to ensure a more uniform distribution of the chiral agent in the liquid crystal box. The heat drying temperature was adjusted to 102°C and the time was extended to 12 minutes, which effectively improved the orientation consistency.

[0074] The optimization measures of Example 2 still strictly comply with the parameter range of the document technical solution. By optimizing the cleaning process, screen printing uniformity and thermal baking conditions, the liquid crystal molecular orientation consistency and display brightness uniformity are further improved. This embodiment is suitable for the production needs of mid-to-high-end display screens, and can effectively reduce the phenomenon of poor orientation and improve display performance.

[0075] Embodiment three:

[0076] Method steps and implementation process:

[0077] Cleaning and drying (S1): Use deionized water to rinse the screen printing surface and treat it with a 60°C special cleaning solution; after cleaning, place it in a drying device, adjust the drying temperature to 78°C, and extend the drying time to 15 minutes to ensure that the surface is completely clean.

[0078] Ambient temperature and humidity control (S2): Before the internal screen printing operation, the ambient temperature is accurately adjusted to 23.7°C, the humidity is adjusted to 55.5%, and the stabilization time is extended to 40 minutes to further reduce the interference of the external environment on the screen printing effect.

[0079] Screen printing operation (S3 & S4): Use 500 mesh BOPP18 wire diameter steel screen, adjust the steel screen tension to 22N, and further reduce the tension difference between the periphery and the center to 0.3N; the ink height is controlled to 4.2μ to ensure the high consistency of the ink layer in the screen printing area.

[0080] Curing (S5): After the screen printing is completed, the product is placed in a curing oven for treatment, the temperature is raised to 190°C, and the curing time is extended to 2 hours and 30 minutes to further improve the adhesion and uniformity of the ink layer.

[0081] De-filming and cleaning (S6): The cleaning line speed is adjusted to 3 m / min and the cleaning liquid temperature is increased to 55 °C to further improve the de-filming and cleaning efficiency and reduce the risk of contamination after cleaning.

[0082] Chiral agent preparation and injection (S7): Chiral agent S811 is prepared, the concentration is increased to 0.26%, and the injection rate is increased to 0.3 ml / s to ensure that the liquid crystal molecules in the liquid crystal box are more accurately and evenly distributed.

[0083] Thermal baking treatment (S8): placing the product racks in an oven, adjusting the rack spacing to 10 mm, setting the thermal baking temperature to 100° C., and extending the thermal baking time to 15 minutes, to further improve the alignment consistency of the liquid crystal molecules.

[0084] Implementation summary:

[0085] On the basis of Example 2, this embodiment further refines and optimizes each link. For example, a special cleaning liquid at 60°C is used in the cleaning stage, and ultrasonic cleaning technology is combined to improve the cleaning effect. The drying temperature is increased to 78°C and the time is extended to 15 minutes, so that the surface cleanliness of the screen printing meets higher requirements. Before the internal screen printing operation, the ambient temperature is accurately adjusted to 23.7°C, the humidity is controlled at 55.5%, and the stabilization time is extended to 40 minutes to minimize the impact of the environment on the screen printing process. In the screen printing stage, the steel mesh tension is adjusted to 22N, the tension difference is reduced to 0.3N, and the ink height is optimized to 4.2μ to ensure that the ink layer distribution is highly consistent. The temperature in the curing stage is increased to 190°C and the time is extended to 2 hours and 30 minutes to further improve the curing effect of the ink layer. The defilming cleaning line speed is increased to 3m / min and the temperature is increased to 55°C, which significantly improves the cleaning efficiency. The concentration of the chiral agent is increased to 0.26%, and the perfusion rate is increased to 0.3ml / s to ensure that the distribution of liquid crystal molecules in the liquid crystal box is more accurate and consistent. The heat-baking temperature was adjusted to 100°C, the time was extended to 15 minutes, and the rack spacing was expanded to 10 mm, which ultimately made the liquid crystal molecules more orderly and the orientation deviation angle less than ±0.8°.

[0086] Based on the documented technical solution, Example 3 further refines the process parameters, and achieves high consistency in the arrangement of liquid crystal molecules through precise environmental control, cleaning technology improvement, and thermal baking optimization. Especially in the production of high-precision display screens, this process can significantly improve the optical performance and brightness uniformity of the product, meeting the strict requirements of high-end display screens.

[0087] Summary:

[0088] Embodiment 1: The basic process significantly improves the poor orientation of liquid crystal molecules by controlling environmental conditions, screen printing process and basic parameters, and is suitable for mass production of ordinary display screens.

[0089] Example 2: The cleaning, curing and heat-drying steps are optimized on the basis of the basic process, and the display uniformity and orientation consistency are improved through higher-precision parameter adjustment, which is suitable for the production of mid-to-high-end display screens.

[0090] Embodiment 3: Through more sophisticated control technology and efficient cleaning means, the orientation accuracy and optical performance of liquid crystal molecules are further improved to meet the highest display quality requirements of high-end display screens.

[0091] Validation Experiment Design:

[0092] Experimental objectives:

[0093] By comparing the production results of the traditional process (control group) and the three embodiments of the present invention (experimental group), the beneficial effects of the present invention in improving the consistency of liquid crystal molecular orientation, improving the uniformity of display brightness and reducing the orientation defect rate in the silk-screen printing area are fully verified.

[0094] Experimental design and process:

[0095] 1. Sample grouping:

[0096] Control group (traditional technology):

[0097] Sample quantity: 200 LCD screens.

[0098] Process characteristics: The ambient temperature and humidity are not strictly controlled; the concentration range of the chiral agent is 0.20%-0.30%; the heat treatment is fixed at 100°C and 10 minutes, and there is no detailed parameter control.

[0099] Experimental Group:

[0100] Example 1: Sample quantity: 200 pieces, using basic technology, strictly controlling temperature, humidity and screen printing parameters, and performing basic optimization.

[0101] Example 2: Sample quantity: 200 pieces, optimize cleaning and screen printing operations, and improve curing and heat baking accuracy.

[0102] Example 3: Sample quantity: 200 pieces, further optimize to fine process and improve the control accuracy of each link.

[0103] 2. Experimental conditions:

[0104] Experimental equipment:

[0105] Polarizing microscope: detects the deviation angle of liquid crystal molecules.

[0106] Optical brightness test equipment: measures the brightness uniformity of samples.

[0107] High-precision cleaning equipment and filling system: ensure filling consistency.

[0108] Environmental control system: strictly control the temperature and humidity of the production environment.

[0109] Detection indicators:

[0110] Liquid crystal molecule offset angle: whether the offset angle is less than ±1°.

[0111] Display brightness uniformity: Test brightness fluctuation range (cd / m 2 ).

[0112] Orientation defect rate in screen printing area: Statistical proportion of defective samples (%).

[0113] 3. Detailed experimental process:

[0114] Production process:

[0115] Control group: 200 LCD screens were produced using traditional technology.

[0116] Experimental Group:

[0117] Embodiment 1: According to the basic process operation, the basic parameters of cleaning, screen printing and heat drying are strictly controlled.

[0118] Embodiment 2: Based on Embodiment 1, the cleaning, curing and pouring steps are optimized to improve the temperature and humidity control accuracy.

[0119] Example 3: Further refine the cleaning (introducing 60°C cleaning liquid treatment) to improve the accuracy of screen printing and injection.

[0120] Testing process:

[0121] Liquid crystal molecule deviation angle detection:

[0122] 50 samples were randomly selected from each group, and the angle of displacement of the liquid crystal molecules was detected using a polarizing microscope, and the angle displacement data of each sample was recorded.

[0123] Display brightness uniformity test:

[0124] The brightness distribution of all samples was measured using an optical brightness test device, and the brightness fluctuation range (cd / m 2 ).

[0125] Statistics of orientation defects in the screen printing area:

[0126] For each group of 200 samples, check whether there is poor orientation in the silk-screen area, record the number of bad samples and calculate the poor orientation rate.

[0127] 4. Experimental data summary:

[0128]

[0129] Experimental analysis and verification

[0130] Liquid crystal molecule orientation consistency:

[0131] Only 65% ​​of the samples in the control group had an offset angle within ±1°, indicating that the traditional process cannot ensure good orientation consistency of liquid crystal molecules.

[0132] Example 1 (85%) significantly improved the liquid crystal molecular alignment by optimizing the basic process, Example 2 (92%) was further optimized, and Example 3 (97%) reached the highest level.

[0133] The gradual reduction of the average offset angle (from ±1.8° to ±0.6°) shows that the technology of the present invention effectively improves the arrangement stability of liquid crystal molecules through more precise environmental and process control.

[0134] Display brightness uniformity:

[0135] The brightness fluctuation range of the control group was larger (±15cd / m 2 ), affecting the display effect.

[0136] The brightness uniformity of Examples 1 to 3 is gradually improved (±10, ±7, ±5 cd / m 2 ), indicating that the technology of the present invention has greatly reduced the brightness unevenness through precise control of the concentration of the chiral agent and heat baking treatment.

[0137] Orientation defect rate of screen printing area:

[0138] The poor orientation rate in the control group was as high as 8%, indicating that traditional processes cannot adequately address this problem.

[0139] The orientation defect rates of Examples 1 to 3 were gradually reduced (3%, 1.5%, 0.5%), and Example 3 in particular almost eliminated the defect problem, verifying the significant effect of the technology of the present invention.

[0140] Experimental summary:

[0141] Comprehensive effect verification:

[0142] The experimental results clearly show that:

[0143] The technical solution of the present invention significantly improves the orientation consistency of liquid crystal molecules, and the deviation angle and brightness uniformity of liquid crystal molecules are greatly improved.

[0144] By strictly controlling the ambient temperature and humidity, screen printing tension, chiral agent concentration and thermal drying conditions, the orientation defect rate in the screen printing area was significantly reduced.

[0145] Effects of different embodiments:

[0146] Example 1: The basic process has a significant effect on improving the arrangement of liquid crystal molecules and is suitable for mass production of ordinary display screens.

[0147] Embodiment 2: Further optimize each link on the basis of the basic process, suitable for the production of mid-to-high-end display screens.

[0148] Embodiment 3: The refined process achieves the best improvement effect and is suitable for high-end display screen requirements.

[0149] Summary Conclusion:

[0150] The experimental results verify the reliability of the technical solution of the present invention. Especially in the production of high-end display screens, the process of Example 3 fully meets the stringent requirements of liquid crystal molecular arrangement consistency and optical performance, providing a reliable basis and significant economic benefits for the improvement of liquid crystal display technology.

[0151] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for improving poor orientation of the screen printing of an internal screen-printed LCD product, characterized in that: The following steps are involved: S1. Clean and dry the screen printing surface; S2. Before the internal screen printing operation, the ambient temperature and humidity must be strictly controlled; S3, use 500 mesh BOPP18 wire diameter steel mesh to control the tension of the steel mesh; S4. When screen printing ink, ensure that the ink height is ≤5μ; S5. Place the silk-screened product in a curing oven for curing; S6. After curing, use the film removal line to clean the product; S7, preparing a chiral agent S811 with a concentration of 0.20-0.26%, and pouring it into the liquid crystal box; S8. If the silk-screen area still has poor orientation, improve the orientation by placing the product rack in an oven and drying it.

2. The method for improving poor orientation of the screen printing of an internal screen-printed LCD product according to claim 1, characterized in that: The environmental temperature and humidity control in step S2 is specifically as follows: The temperature is maintained at 23±3℃, the humidity is controlled at 53-58%RH, and the internal screen printing operation can only be carried out after the environmental conditions have been stable for more than 30 minutes.

3. The method for improving poor orientation of the screen printing of an internal screen-printed LCD product according to claim 1, characterized in that: In step S3, the tension of the steel mesh is controlled at 22-23N, and the equipment is calibrated so that the tension difference between the periphery and the center of the steel mesh does not exceed 1N.

4. The method for improving poor orientation of the screen printing of an internal screen-printed LCD product according to claim 1, characterized in that: In step S5, the curing temperature is controlled at 160-200° C., and the curing time is 1.5-2.5 hours.

5. The method for improving poor orientation of the screen printing of an internal screen-printed LCD product according to claim 1, characterized in that: In step S6, the cleaning line speed is set to 2-3 m / min, and the cleaning liquid temperature is controlled within the range of 40-60°C.

6. The method for improving poor orientation of the screen printing of an internal screen-printed LCD product according to claim 1, characterized in that: The concentration range of the chiral agent S811 in step S7 is further refined as follows: When the concentration is 0.20-0.24%, it is used to improve the low orientation defect rate in the liquid crystal box; When the concentration is 0.24-0.26%, it is used to improve the liquid crystal cell with high requirements for orientation consistency; The perfusion rate of the chiral agent is controlled at 0.1-0.3 ml / s.

7. The method for improving poor orientation of the screen printing of an internal screen-printed LCD product according to claim 1, characterized in that: During the heat-baking improvement process in step S8, the spacing between the racks of the product placed in the oven is controlled to be 5-10 mm, the heat-baking temperature is set to 100° C., and the time is 10-15 minutes. After the heat-baking is completed, a polarizing microscope is used to detect whether the orientation deviation angle of the liquid crystal molecules is less than ±1°.

8. The method for improving poor orientation of the screen printing of an internal screen-printed LCD product according to claim 1, characterized in that: In step S1, the drying temperature is set to 70-80° C., and the drying time is controlled to 10-15 min.

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