Laminating multi-section type defoaming process method
By dividing the defoaming process of LCD screens into multiple stages and controlling the temperature and pressure in different stages, the problem of poor filling of optical glue in blind holes is solved, efficient one-time defoaming is achieved, production costs are reduced and product quality is improved.
Patent Information
- Application Number
- CN202511070929.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2025-09-19
AI Technical Summary
In the process of optical adhesive filling in blind holes of existing liquid crystal displays, the commonly used fixed temperature and pressure mode cannot meet the requirements of different filling heights, resulting in a high defoaming defect rate and requiring secondary defoaming to achieve the yield target.
A multi-stage defoaming process is adopted for bonding, and the defoaming process is divided into four stages, with temperature, pressure and time set respectively, including preheating, pressurized defoaming, first pressure relief and second pressure relief. By controlling the temperature and pressure in stages, the viscous flow properties of the optical adhesive are improved to ensure that the optical adhesive fully fills the blind holes and discharges bubbles.
It improves the yield of primary defoaming, reduces the need for secondary defoaming, reduces production costs, improves product quality, and reduces labor and efficiency costs.
Smart Images
Figure CN120669447A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of liquid crystal display technology, and more specifically, relates to a multi-stage defoaming process method for bonding. Background Art
[0002] In liquid crystal displays, in order to further increase the utilization area of the front display area, it is usually necessary to punch a hole in the LCD screen to accommodate the front camera. Currently, there are two ways to punch holes. One is the through-hole solution, that is, all layers except the outermost cover glass are perforated; the other is the blind hole solution, that is, the liquid crystal layer and the cover glass are not perforated, and the other layers, such as the upper polarizer, the lower polarizer and the backlight module are perforated, and the front camera is embedded in the hole formed after the lower polarizer and the backlight module are opened. Because the blind hole solution is simpler and more cost-effective, it has become the mainstream solution for existing product designs. However, in the blind hole solution, since the depth of the blind hole at the upper polarizer is as much as 75μm, the optical glue at the blind hole needs to be under high temperature and high pressure to have good viscous flow properties. Therefore, the pressure and temperature required for the optical glue to fill the blind hole need to be higher than other parts of the LCD screen. However, the current defoaming process, which uses a fixed temperature and pressure model, cannot simultaneously meet the temperature and pressure requirements of different product filling heights. This results in a high rejection rate after a single defoaming step, necessitating a secondary defoaming step to achieve the desired yield. Therefore, improving the optical adhesive filling in blind vias to increase defoaming yields has become an urgent issue. Summary of the Invention
[0003] The purpose of the embodiments of the present application is to provide a multi-stage defoaming process method for laminating to solve the above-mentioned technical problems existing in the prior art.
[0004] To achieve the above-mentioned objectives, the technical solution adopted in the present application is as follows: providing a multi-stage defoaming process method for defoaming a liquid crystal display screen, wherein the liquid crystal display screen includes, from the outside to the inside, a cover plate, an optical adhesive layer, an upper polarizer, a liquid crystal module, a lower polarizer, a backlight module, and a camera; the upper polarizer is perforated and forms a first blind hole with the unperforated liquid crystal module; the backlight module and the lower polarizer are both perforated and form a second blind hole with the unperforated liquid crystal module; the camera is embedded in the second blind hole, and the first blind hole and the second blind hole are located in corresponding positions; the multi-stage defoaming process method comprises the following steps:
[0005] The LCD screen to be defoamed is placed in the chamber of a vacuum pressurized defoaming machine, and the defoaming machine is evacuated to reach a preset negative pressure value in the chamber;
[0006] In the first stage of a defoaming operation, the temperature in the chamber of the defoaming machine is raised to a preset defoaming temperature within a first preset time period;
[0007] In the second stage of the primary defoaming, the defoaming machine performs pressurized defoaming treatment on the liquid crystal display screen within a second preset time period, at a defoaming temperature, and under a preset first defoaming pressure, so that the optical adhesive in the optical adhesive layer fully fills the first blind hole;
[0008] In the third stage of the primary defoaming, the defoaming machine performs a first pressure relief process on the LCD screen within a third preset time period, at a defoaming temperature, and under a preset second defoaming pressure;
[0009] In the fourth stage of the primary defoaming, within the fourth preset time period and at the defoaming temperature and the preset third defoaming pressure, the defoaming machine performs a second pressure relief process on the LCD screen;
[0010] Among them, the second preset time period is greater than the first preset time period, the first preset time period is greater than the third preset time period and the fourth preset time period; the first defoaming pressure is greater than the second defoaming pressure, the second defoaming pressure is greater than the third defoaming pressure, and the third defoaming pressure is greater than or equal to atmospheric pressure.
[0011] Optionally, the second preset time period is 6 times the first preset time period, and the third preset time period and the fourth preset time period are both 0.6 times the first preset time period.
[0012] The tolerance of the second preset time period is greater than the tolerance of the first preset time period, and the tolerance of the third preset time period and the tolerance of the fourth preset time period are both consistent with the tolerance of the first preset time period.
[0013] Optionally, the first defoaming pressure is 2 to 3 times the second defoaming pressure, and the second defoaming pressure is 2 times the third defoaming pressure;
[0014] The tolerance of the first defoaming pressure is greater than the tolerance of the second defoaming pressure, and the tolerance of the second defoaming pressure is consistent with the tolerance of the third defoaming pressure.
[0015] Optionally, the defoaming temperature ranges from 55±5°C to 65±5°C.
[0016] Optionally, the optical adhesive layer is composed of optical adhesive, and before the step of placing the liquid crystal display screen to be defoamed into the defoaming machine, the method further includes the following steps:
[0017] The parameter information corresponding to different types or brands of optical adhesives when achieving the best defoaming effect is tested and determined separately. The parameter information includes defoaming temperature, the length of the first preset time period, the length of the second preset time period, the length of the third preset time period, the length of the fourth preset time period, the first defoaming pressure, the second defoaming pressure and the third defoaming pressure.
[0018] Optionally, before the step of placing the LCD screen to be defoamed into the defoaming machine, the following steps are further included:
[0019] Input the parameter information corresponding to each type or brand of optical adhesive for achieving the best defoaming effect into the main control system of the defoaming machine;
[0020] All parameter information of each type or brand of optical adhesive is integrated into a defoaming process mode in the main control system;
[0021] Before defoaming a liquid crystal display screen having one of the optical adhesives, call out the corresponding defoaming process mode from the main control system.
[0022] Optionally, the second stage of primary defoaming includes the following sub-steps:
[0023] The defoamer's pressurization system is turned on and compressed air is injected into the cavity;
[0024] The air pressure in the cavity is pressurized to a first defoaming pressure;
[0025] At the first defoaming pressure and defoaming temperature, the air pressure state in the cavity is maintained for a second preset time period;
[0026] The softened optical adhesive of the optical adhesive layer fills the first blind hole under the first defoaming pressure.
[0027] Optionally, in the first stage of a defoaming operation, the air pressure in the chamber rises from a preset negative pressure value to 0 MPa.
[0028] Optionally, the pressurizing system of the defoaming machine includes a solenoid valve. In the second stage of a defoaming operation, the solenoid valve controls the pressure fluctuation of the first defoaming pressure to be 0.1 MPa; in the third stage of a defoaming operation and the fourth stage of a defoaming operation, the solenoid valve controls the pressure fluctuation of the first defoaming pressure to be 0.05 MPa.
[0029] Optionally, after the fourth stage of the primary defoaming, the following steps are further included:
[0030] Turn off the heating system of the defoamer, start the cooling fan or allow natural cooling to reduce the inner cavity temperature of the defoamer from the defoaming temperature to room temperature;
[0031] De-vacuuming the chamber of the defoaming machine to obtain a defoamed LCD screen;
[0032] Performing appearance inspection on the defoamed LCD screen, and judging the LCD screen without bubbles as qualified LCD screen;
[0033] Perform UV curing on qualified LCD screens.
[0034] The beneficial effect of the multi-stage defoaming process provided by the present application is that by decomposing the process of the primary defoaming process into four stages, the temperature, pressure, and duration of the four stages can be set respectively, and the heat preservation and pressure holding time after the temperature is increased, that is, when the temperature and pressure in the chamber of the defoaming machine reach the preset defoaming temperature and the preset first defoaming pressure, the heat preservation and pressure holding time can be continued at the defoaming temperature, so that the optical adhesive at the first blind hole can obtain better viscous flow properties under high temperature and high pressure for a longer time, thereby better filling the first blind hole. At the same time, the bubbles at the first blind hole and the bubbles in the optical adhesive layer can also be better discharged. In this way, the problem of low yield of blind hole bubbles generated in the production process due to the blind hole design can be well solved. Therefore, compared with the current common solution that requires secondary defoaming to achieve the defoaming yield, the technical solution of the present application is equivalent to integrating the primary and secondary defoaming processes in a staged defoaming process, thereby greatly improving the yield of the primary defoaming of the laminating bubbles, reducing the labor cost and efficiency cost of the secondary defoaming of the liquid crystal display, and thus helping to reduce the production cost of the product and improve the product quality. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0036] Figure 1 A partial structural cross-sectional view of a liquid crystal display screen provided in an embodiment of the present application;
[0037] Figure 2 This is a flow chart of the multi-stage defoaming process provided in an embodiment of the present application.
[0038] Description of Figure Numbers:
[0039] Label name Label name 100 Cover 200 Optical adhesive layer 310 Upper polarizer 400 LCD modules 320 Lower polarizer 500 Backlight module 600 Camera 710 First blind hole 720 Second blind hole DETAILED DESCRIPTION
[0040] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.
[0041] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.
[0042] It should also be noted that the directional terms such as left, right, up and down in the embodiments of the present application are merely relative concepts or are based on the normal use status of the product, and should not be considered as restrictive.
[0043] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.
[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.
[0045] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.
[0046] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.
[0047] The embodiment of the present application provides a multi-stage defoaming process method for bonding.
[0048] See also Figure 1 and Figure 2In one embodiment, the multi-stage defoaming process is used for defoaming liquid crystal display screens. Specifically, Figure 1 As shown, the LCD screen includes, from outside to inside, a cover plate 100, an optical adhesive layer 200, an upper polarizer 310, a liquid crystal module 400, a lower polarizer 320, a backlight module 500, and a camera 600. The upper polarizer 310 is perforated and forms a first blind hole 710 with the liquid crystal module 400 (which does not have a perforation). The backlight module 500 and the lower polarizer 320 are both perforated and form a second blind hole 720 with the liquid crystal module 400 (which does not have a perforation). The camera 600 is embedded in the second blind hole 720. The first blind hole 710 and the second blind hole 720 correspond to each other in position.
[0049] Accordingly, if Figure 2 As shown, the multi-stage defoaming process includes the following steps:
[0050] S1. Place the LCD screen to be defoamed into the chamber of a vacuum pressurized defoaming machine, and evacuate the chamber to reach a preset negative pressure value;
[0051] S2. In the first stage of a defoaming operation, the temperature in the chamber of the defoaming machine is raised to a preset defoaming temperature within a first preset time period;
[0052] S3, in the second stage of the primary defoaming, within a second preset time period, at a defoaming temperature, and at a preset first defoaming pressure, the defoaming machine performs a pressurized defoaming process on the liquid crystal display screen, so that the optical adhesive in the optical adhesive layer 200 fully fills the first blind hole 710;
[0053] S4. In the third stage of the primary defoaming, the defoaming machine performs a first pressure relief process on the LCD screen within a third preset time period, at a defoaming temperature, and at a preset second defoaming pressure;
[0054] S5. In the fourth stage of the primary defoaming, the defoaming machine performs a second pressure relief process on the LCD screen within a fourth preset time period, at a defoaming temperature, and under a preset third defoaming pressure;
[0055] Among them, the second preset time period is greater than the first preset time period, the first preset time period is greater than the third preset time period and the fourth preset time period; the first defoaming pressure is greater than the second defoaming pressure, the second defoaming pressure is greater than the third defoaming pressure, and the third defoaming pressure is greater than or equal to atmospheric pressure.
[0056] Based on this design, in this embodiment, by decomposing the defoaming process into four stages, the temperature, pressure, and duration of each stage can be set separately. At the same time, the heat preservation and pressure holding time after the temperature rise is increased. That is, when the temperature and pressure in the chamber of the defoaming machine reach the preset defoaming temperature and the preset first defoaming pressure, the heat preservation and pressure holding can be continued at the defoaming temperature. As a result, the optical adhesive in the first blind hole 710 can achieve better viscous flow properties under high temperature and high pressure for a longer period of time, thereby better filling the first blind hole 710. At the same time, the bubbles in the first blind hole 710 and the bubbles in the optical adhesive layer 200 can also be better discharged. In this way, the problem of low yield of blind hole bubble defoaming caused by the blind hole design during the production process can be effectively solved. Therefore, compared with the current common solution that requires secondary defoaming to achieve the defoaming yield, the technical solution of the present application is equivalent to integrating the primary defoaming and secondary defoaming processes in stages in the primary defoaming process, thereby greatly improving the yield of the primary defoaming of the laminating bubbles, reducing the labor cost and efficiency cost of the secondary defoaming of the LCD screen, and thus helping to reduce the production cost of the product and improve product quality.
[0057] Furthermore, the defoaming temperature range is 55±5°C to 65±5°C. It is understood that if the temperature is too low, the optical adhesive will not have good viscous flow properties at lower temperatures, and its filling effect on the first blind hole 710 and defoaming effect will not be ideal. If the temperature is too high, it will cause problems such as material aging. Only when it is within this preferred temperature range can a better defoaming effect be obtained and other problems caused by high temperature can be avoided.
[0058] Furthermore, the second preset time period is six times the first preset time period, and the third and fourth preset time periods are each 0.6 times the first preset time period. The tolerance of the second preset time period is greater than the tolerance of the first preset time period, and the tolerances of the third and fourth preset time periods are consistent with the tolerance of the first preset time period. In other words, in this embodiment, because the second stage of the primary defoaming process is the primary defoaming stage, the second preset time period is significantly longer than the second, third, and fourth preset time periods. This provides sufficient time and a higher temperature for the optical adhesive in the first blind hole 710 to flow, thereby ensuring that the optical adhesive is properly filled in the first blind hole 710 and that bubbles in the first blind hole 710 and other bubbles in the LCD are effectively discharged.
[0059] Furthermore, the first defoaming pressure is 2 to 3 times the second defoaming pressure, and the second defoaming pressure is 2 times the third defoaming pressure. The tolerance of the first defoaming pressure is greater than the tolerance of the second defoaming pressure, and the tolerance of the second defoaming pressure is consistent with the tolerance of the third defoaming pressure. It can be understood that in the second stage of the main defoaming, the pressure in the defoaming machine chamber, that is, the first defoaming pressure, should be much greater than the pressure in other stages. Only in this way can the defoaming effect at the first blind hole 710 be ensured. The second defoaming pressure is greater than the third defoaming pressure, which means that the third and fourth stages are a staged pressure relief process, thereby avoiding the phenomenon of screen deformation caused by sudden pressure difference of the LCD screen. In addition, in the first stage of a defoaming, the air pressure in the chamber rises from the preset negative pressure value to 0 MPa, that is, in the first stage, the pressure is appropriately increased while the temperature is rising, thereby avoiding the sudden increase in pressure in the second stage and causing adverse effects on the LCD screen.
[0060] Specifically, the second stage of the primary defoaming process includes the following steps: First, the defoaming machine's pressurization system is activated to inject compressed air into the cavity. The air pressure within the cavity is then increased to a first defoaming pressure. The air pressure within the cavity is then maintained at the first defoaming pressure and temperature for a second predetermined period of time. During this extended period of pressure maintenance, the softened optical adhesive in the optical adhesive layer 200 fills the first blind hole 710 at the first defoaming pressure.
[0061] Furthermore, the optical adhesive layer 200 is composed of optical adhesive. Prior to placing the LCD screen to be defoamed into the defoamer, the following steps are also performed: testing and determining the parameter information corresponding to achieving the optimal defoaming effect for different types or brands of optical adhesive. The parameter information includes the defoaming temperature, the duration of the first preset time period, the duration of the second preset time period, the duration of the third preset time period, the duration of the fourth preset time period, the first defoaming pressure, the second defoaming pressure, and the third defoaming pressure. These parameter information can be obtained through methods such as DOE experiments. After measuring the various parameters of commonly used types or brands of optical adhesive, the following steps should be performed: First, the parameter information corresponding to achieving the optimal defoaming effect for each type or brand of optical adhesive is input into the main control system of the defoamer. Then, all parameter information for each type or brand of optical adhesive is integrated into a defoaming process mode in the main control system. Thus, before defoaming an LCD screen using one of the optical adhesives, the corresponding defoaming process mode is called up from the main control system, thereby implementing the aforementioned multi-stage defoaming process method for lamination. It can be understood that this method of measuring various parameter information in advance according to the type or brand of optical adhesive can enable the LCD screen to select the appropriate defoaming process and parameters according to the type or brand of optical adhesive actually used without the need for additional settings, and can realize the combination selection of multiple temperature and pressure modes.
[0062] The following takes a type of LCD screen as an example to directly illustrate the process of the multi-stage defoaming process.
[0063] The figure below shows the relevant parameter information.
[0064]
[0065] First, in the first stage of primary defoaming, the defoamer's heating system is turned on, raising the chamber temperature to approximately 65°C over a period of approximately 5 minutes. Simultaneously, the chamber pressure increases from negative pressure to 0 MPa. Then, in the second stage of primary defoaming, the chamber temperature remains at approximately 65°C, but the pressure is increased to approximately 0.45 MPa for approximately 30 minutes to achieve the primary defoaming process. This time and temperature are typically higher than those typically used for primary defoaming, enabling better blind hole defoaming. Then, in the third stage of primary defoaming, the temperature remains at approximately 65°C, but the pressure is reduced from 0.45 MPa to approximately 0.2 MPa over approximately 3 minutes, achieving the initial pressure relief and subsequent supplementary defoaming at a higher temperature. Then, in the fourth stage of the primary defoaming, the temperature continues to be maintained at about 65°C, but the air pressure is also reduced from 0.2 MPa to about 0.1 MPa in about 3 minutes, that is, to normal pressure, thereby achieving a second pressure relief and further subsequent supplementary defoaming effect at a higher temperature.
[0066] Furthermore, after the fourth stage of primary defoaming, the following steps are also included: First, the defoamer's heating system is turned off, and a cooling fan or natural cooling is activated to reduce the internal temperature of the defoamer from the defoaming temperature to room temperature. The defoamer's chamber is then de-vacuumed to obtain a defoamed LCD screen. The defoamed LCD screen is then visually inspected, and screens free of bubbles are deemed qualified. Finally, qualified LCD screens are UV-cured.
[0067] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.
Claims
1. A multi-stage lamination defoaming process method for defoaming a liquid crystal display screen, wherein the liquid crystal display screen comprises, from the outside to the inside, a cover plate, an optical adhesive layer, an upper polarizer, a liquid crystal module, a lower polarizer, a backlight module, and a camera; the upper polarizer is perforated and forms a first blind hole with the unperforated liquid crystal module; the backlight module and the lower polarizer are both perforated and form a second blind hole with the unperforated liquid crystal module; the camera is embedded in the second blind hole, and the first blind hole and the second blind hole are located in corresponding positions; characterized in that: The multi-stage laminating defoaming process method comprises the following steps: The liquid crystal display screen to be defoamed is placed in the chamber of a vacuum pressurized defoaming machine, and the defoaming machine is evacuated to reach a preset negative pressure value in the chamber; In the first stage of a defoaming operation, the temperature in the chamber of the defoaming machine is raised to a preset defoaming temperature within a first preset time period; In the second stage of the primary defoaming, the defoaming machine performs pressurized defoaming treatment on the liquid crystal display screen within a second preset time period, at the defoaming temperature, and under the preset first defoaming pressure, so that the optical adhesive in the optical adhesive layer fully fills the first blind hole; In the third stage of the primary defoaming, within a third preset time period and at the defoaming temperature and the preset second defoaming pressure, the defoaming machine performs a first pressure relief process on the liquid crystal display screen; In the fourth stage of the primary defoaming, within a fourth preset time period and at the defoaming temperature and the preset third defoaming pressure, the defoaming machine performs a second pressure relief process on the liquid crystal display screen; Among them, the second preset time period is greater than the first preset time period, the first preset time period is greater than the third preset time period and the fourth preset time period; the first defoaming pressure is greater than the second defoaming pressure, the second defoaming pressure is greater than the third defoaming pressure, and the third defoaming pressure is greater than or equal to atmospheric pressure.
2. The laminating multi-stage defoaming process according to claim 1, characterized in that: The second preset time period is 6 times the first preset time period, and the third preset time period and the fourth preset time period are both 0.6 times the first preset time period. The tolerance of the second preset time period is greater than the tolerance of the first preset time period, and the tolerance of the third preset time period and the tolerance of the fourth preset time period are both consistent with the tolerance of the first preset time period.
3. The laminating multi-stage defoaming process according to claim 1, characterized in that: The first defoaming pressure is 2 to 3 times the second defoaming pressure, and the second defoaming pressure is 2 times the third defoaming pressure; The tolerance of the first defoaming pressure is greater than the tolerance of the second defoaming pressure, and the tolerance of the second defoaming pressure is consistent with the tolerance of the third defoaming pressure.
4. The laminating multi-stage defoaming process according to claim 1, characterized in that: The defoaming temperature ranges from 55±5°C to 65±5°C.
5. The laminating multi-stage defoaming process according to any one of claims 1 to 4, characterized in that: The optical adhesive layer is composed of optical adhesive, and the step of placing the liquid crystal display screen to be defoamed into the defoaming machine also includes the following steps: The parameter information corresponding to the different types or brands of optical adhesives when achieving the best defoaming effect is tested and determined respectively, and the parameter information includes the defoaming temperature, the length of the first preset time period, the length of the second preset time period, the length of the third preset time period, the length of the fourth preset time period, the first defoaming pressure, the second defoaming pressure and the third defoaming pressure.
6. The laminating multi-stage defoaming process according to claim 5, characterized in that: The step of placing the liquid crystal display screen to be defoamed into the defoaming machine also includes the following steps: Inputting the parameter information corresponding to the best defoaming effect of each type or brand of optical adhesive into the main control system of the defoaming machine; All the parameter information of each type or brand of the optical adhesive is integrated into a defoaming process mode in the main control system; Before defoaming the liquid crystal display screen having one of the optical adhesives, the corresponding defoaming process mode is called out from the main control system.
7. The laminating multi-stage defoaming process according to claim 5, characterized in that: The second stage of the primary defoaming comprises the following sub-steps: The pressurizing system of the defoaming machine is turned on to inject compressed air into the chamber; The air pressure in the chamber is pressurized to the first defoaming pressure; At the first defoaming pressure and the defoaming temperature, the air pressure state in the chamber is maintained for a second preset time period; The softened optical adhesive of the optical adhesive layer fills the first blind hole under the first defoaming pressure.
8. The laminating multi-stage defoaming process according to claim 5, characterized in that: In the first stage of the primary defoaming, the air pressure in the chamber rises from the preset negative pressure value to 0 MPa.
9. The laminating multi-stage defoaming process according to claim 1, characterized in that: The pressurizing system of the defoaming machine includes a solenoid valve. In the second stage of the primary defoaming, the solenoid valve controls the pressure fluctuation of the first defoaming pressure to be 0.1 MPa; in the third stage of the primary defoaming and the fourth stage of the primary defoaming, the solenoid valve controls the pressure fluctuation of the first defoaming pressure to be 0.05 MPa.
10. The laminating multi-stage defoaming process according to claim 9, characterized in that: After the fourth stage of the primary defoaming, the method further comprises the following steps: Turn off the heating system of the defoamer, start the cooling fan or natural cooling, so that the inner cavity environment temperature of the defoamer drops from the defoaming temperature to room temperature; performing a de-vacuum treatment on the chamber of the defoaming machine to obtain the de-foamed liquid crystal display screen; Performing an appearance inspection on the liquid crystal display screen after defoaming, and determining the liquid crystal display screen without bubbles after the appearance inspection as a qualified liquid crystal display screen; The qualified liquid crystal display screen is subjected to UV curing treatment.