Full-lamination method and full-lamination equipment of display device and display device

Abstract

The invention relates to a full-lamination method and device of a display device and the display device.The full-lamination method comprises the steps that firstly, a lamination area of a first panel is coated with liquid optical cement, the lamination area is covered with the liquid optical cement, then an initial glue layer is formed on one face of the first panel through a curing process, and the thickness of the initial glue layer is 0.55 mm-0. 65 mm; liquid optical cement is coated on a glue coating area of one face, deviating from the first panel, of the initial glue layer, the glue coating area is located in the central area of the initial glue layer, the area of the glue coating area is 1 / 2-4 / 5 of the area of the attaching area, and the maximum thickness of the coated liquid optical cement is 0.05 mm-0. 25mm; the second panel is placed on the side, provided with the liquid optical cement, of the first panel, pressing and defoaming treatment are conducted, and then curing is conducted to obtain the full-lamination display device. According to the laminating method, the bubble reversing phenomenon in the manufacturing process of the display device is reduced or even eliminated, the product yield is improved, the display effect of the display device is improved, and the resolution ratio, the contrast ratio and other performance are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing display devices, and in particular to a full-lamination method for a display device, a full-lamination device and a display device. Background Art

[0002] As people's demand for display becomes higher and higher, optical glue is often used to fully bond the display screen and the glass cover plate in the display device. In the existing full bonding process, some use double-sided optical tape to bond the display screen and the glass cover plate, and some directly apply liquid optical glue to the display screen, and then cover the glass cover plate on the liquid optical glue layer, and fully bond the display screen and the glass cover plate through the process of degassing and pressing. However, both methods have serious anti-bubble phenomenon after bonding, that is, there are many bubbles between the display panel and the glass cover plate. Especially with the continuous increase in production capacity, the product defective problems caused by the above-mentioned bubble problem are becoming more and more serious; and this display screen with bubbles will also affect the display effect, especially when used in the instrument screen and central control screen in the automotive field, the display effect is poor, and even affects the performance such as resolution and contrast, seriously affecting the driver's energy, and may cause safety hazards. Summary of the invention

[0003] Based on the above situation, the main purpose of the present invention is to provide a full-bonding method, full-bonding equipment and display device for a display device, so as to reduce or even eliminate the anti-bubble phenomenon in the manufacture of the display device, improve the product yield, increase the display effect of the display device, and enhance the performance such as resolution and contrast.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A first aspect of the present invention provides a full bonding method for a display device, wherein the display device comprises a first panel and a second panel, wherein the first panel and the second panel are fully bonded via an optical adhesive layer; the full bonding method comprises the following steps:

[0006] S10: applying liquid optical adhesive to the bonding area of ​​the first panel so that the liquid optical adhesive covers the bonding area, and then forming an initial adhesive layer on one side of the first panel through a curing process; wherein the thickness of the initial adhesive layer is 0.55 mm to 0.65 mm;

[0007] S20: applying liquid optical adhesive to the adhesive coating area on the side of the initial adhesive layer facing away from the first panel, wherein the adhesive coating area is located in the central area of ​​the initial adhesive layer, and its area is 1 / 2 to 4 / 5 of the area of ​​the bonding area, and the maximum thickness of the applied liquid optical adhesive is 0.05 mm to 0.25 mm;

[0008] S30: placing the second panel on the side of the first panel where the liquid optical adhesive is disposed, and pressing the panel together so that the liquid optical adhesive applied in step S20 covers the initial adhesive layer, forming an uncured adhesive layer, and obtaining a semi-finished device;

[0009] S40: performing a defoaming treatment on the semi-finished device, and then fully bonding the first panel and the second panel through the optical adhesive layer through a curing process to obtain a fully bonded display device; wherein the initial adhesive layer and the uncured adhesive layer jointly form the optical adhesive layer during the curing process;

[0010] The liquid optical adhesive selected in step S10 is the same as that selected in step S20.

[0011] Optionally, in step S10, the curing time of the curing process is 10 to 20 minutes, and the curing temperature is 60° C. to 80° C.

[0012] Optionally, in step S10, the curing time of the curing process is 15 minutes and the curing temperature is 70°C.

[0013] Optionally, in the step S20, the liquid optical adhesive is coated by a liquid optical adhesive coating knife so that the coverage area of ​​the formed adhesive film is 2 / 3 of the area of ​​the bonding area.

[0014] Optionally, in the step S20, the maximum thickness of the adhesive film formed by the applied liquid optical adhesive and the initial adhesive layer is less than or equal to 0.8 mm, and the minimum distance between the edge of the adhesive film and the edge of the first panel is 8 mm to 15 mm.

[0015] Optionally, the viscosity of the liquid optical adhesive in step S10 and step S20 is 800 mPa·s to 1200 Pa·sPa·s, and the shear strength and positive tensile strength after curing are both greater than or equal to 0.2 MPa.

[0016] Optionally, in step S30, the pressing is performed along a direction from the center to the edge, so that the first panel and the second panel are gradually and closely fitted from the center to the edge.

[0017] Optionally, in the step S30, the pressing force in the pressing process is 0.015Mpa to 0.025Mpa; in the step S40, the curing time in the curing process is 15 minutes to 20 minutes, the curing temperature is 70°C to 80°C, and the thickness of the optical adhesive layer formed by curing is less than or equal to 0.7mm.

[0018] A second aspect of the present invention provides a full bonding device for a display device, which is used to perform any of the full bonding methods described above; the display device comprises a first panel and a second panel, and the first panel and the second panel are fully bonded by an optical adhesive layer; the full bonding device comprises:

[0019] A glue coating device, used to perform the process of coating liquid glue in step S10 and step S20;

[0020] A curing device, used to perform the curing process in step S10 and step S40;

[0021] A defoaming device, used to perform the defoaming process in step S40;

[0022] The pressing device is used to perform the pressing process in step S30.

[0023] A third aspect of the present invention provides a display device, comprising a first panel and a second panel, wherein the first panel and the second panel are fully bonded together by an optical adhesive layer, and the first panel and the second panel are bonded together by any of the above-mentioned full bonding methods;

[0024] The thickness of the optical adhesive layer is less than or equal to 0.7 mm, the number of bubbles per unit area in the bubble test of the display device is less than 2, the high temperature resistance reaches above 85° C., and the humidity resistance reaches above 85% rh.

[0025] Optionally, the display device includes an instrument screen, the first panel is a display panel of the instrument screen, and the second panel is a glass cover of the instrument screen.

[0026] The present invention adopts a secondary glue coating process, wherein the first full-area coating is directly cured, and the thickness of the initial glue layer formed is controlled to be 0.55 mm to 0.65 mm. After the second partial coating, the first panel and the second panel are pressed together, and then cured after degassing treatment, and the area of ​​the second coating is controlled to be 1 / 2 to 4 / 5 of the area of ​​the bonding area. The maximum thickness of the coated liquid optical glue is 0.05 mm to 0.25 mm. In this way, although the first full-area coating is performed, since it is directly cured without going through the pressing process, there are basically no bubbles in the formed initial glue layer. Although the pressing process is passed after the second glue coating, the thickness of the glue layer is very thin and is mainly used to achieve bonding of the second panel. Therefore, bubbles are basically not generated during the pressing process, thereby improving the display effect of the finished display device and improving its performance such as resolution and contrast. The initial adhesive layer also functions as a double-sided optical adhesive tape, which can achieve firm bonding to the first panel, and then solidify together with the second applied liquid optical adhesive to form a firm bond with the second panel, thereby ensuring the reliability of bonding between the first panel and the second panel; at the same time, through the thickness of the first adhesive coating, it is possible to compensate for manufacturing errors such as the flatness of the first panel to a certain extent, further reducing or even avoiding the presence of bubbles in the optical adhesive layer of the manufactured display device.

[0027] At the same time, since the same liquid optical glue is used for the first and second coatings, even if the first coating solidifies into an initial glue layer, the second coating can be completely integrated with the initial glue layer when it is cured after the second coating, without causing stratification that affects the display effect.

[0028] Therefore, the full bonding method of the display device of the present invention can reduce or even eliminate the anti-bubble phenomenon in the manufacture of the display device, improve the product yield, increase the display effect of the display device, and enhance the performance such as resolution and contrast.

[0029] Other beneficial effects of the present invention will be explained in the specific implementation manner through the introduction of specific technical features and technical solutions. Through the introduction of these technical features and technical solutions, those skilled in the art should be able to understand the beneficial technical effects brought about by the technical features and technical solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

[0031] Figure 1 A schematic flow chart of a preferred embodiment of a full bonding method for a display device provided by the present invention;

[0032] Figure 2 A schematic diagram of a structure after executing step S10 in a preferred embodiment of the full-bonding method for a display device provided by the present invention;

[0033] Figure 3 This is a schematic diagram of a structure after executing step S20 in another preferred embodiment of the full-bonding method for a display device provided by the present invention;

[0034] Figure 4 This is a schematic structural diagram after executing step S30 in another preferred embodiment of the full-bonding method for a display device provided by the present invention;

[0035] Figure 5 This is a schematic structural diagram after executing step S40 in a preferred implementation of the full-bonding method for a display device provided by the present invention.

[0036] In the figure:

[0037] 100, first panel; 200, second panel; 300, optical adhesive layer; 310, initial adhesive layer; 320, uncured adhesive layer. DETAILED DESCRIPTION

[0038] The present invention is described below based on embodiments, but the present invention is not limited to these embodiments. In the following detailed description of the present invention, some specific details are described in detail. In order to avoid confusing the essence of the present invention, known methods, processes, procedures, and components are not described in detail.

[0039] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes and are not necessarily drawn to scale.

[0040] Unless the context clearly requires otherwise, throughout the specification and claims, the words "include", "comprising" and similar words should be interpreted in an inclusive sense rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to".

[0041] In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0042] The present invention provides a full bonding method for a display device, which can be applied to automobile instrument screens, central control screens, and other fields such as smart display terminals such as mobile phones. Specifically, Figure 5As shown, the display device includes a first panel 100 and a second panel 200, and the first panel 100 and the second panel 200 are fully bonded by an optical adhesive layer 300. The first panel 100 can be a display panel, and the second panel 200 can be a glass cover. The display device can be a non-touch display device or a touch display device. When it is a non-touch display device, the display panel includes a display screen, that is, a non-touch display panel; when the display device is a touch display device, the display panel includes a display screen and a touch screen (or a touch film), that is, the display panel is a touch display panel. Specifically, the first panel 100 has a bonding area on one side facing the second panel 200, that is, the area where the first panel 100 is bonded to the optical adhesive layer. Generally, there is a certain distance between the bonding area and the edge of the first panel. Specifically, the bonding area can correspond to the display area of ​​the display device.

[0043] refer to Figure 1 The full lamination method of the present invention comprises the steps of:

[0044] S10: Coating liquid optical adhesive on the bonding area of ​​the first panel 100 so that the liquid optical adhesive covers the bonding area of ​​the first panel 100, and then forming an initial adhesive layer 310 on one side of the first panel 100 through a curing process. Figure 2 As shown; wherein, the thickness of the initial adhesive layer 310 is 0.55mm to 0.65mm.

[0045] Among them, a surface of the first panel 100 with a larger area is a bonding area. After the first panel 100 and the second panel 200 are bonded, this surface is bonded to the optical adhesive layer and faces the second panel 200 .

[0046] In step S10, the first glue coating is performed, and the liquid optical glue is coated on the entire bonding area of ​​the first panel 100 during the glue coating. After that, no pressing is performed, and a curing treatment is directly performed to solidify the first coated liquid optical glue, thereby forming an initial glue layer 310. The initial glue layer 310 is a part of the optical glue layer 300 in the display device, and its thickness is less than the thickness of the optical glue layer 300, but the coverage area of ​​the first panel 100 is the same as the coverage area of ​​the optical glue layer 300. The thickness of the initial glue layer 310 is 0.55 mm to 0.65 mm, that is, the liquid optical glue after the first glue coating is cured to form an initial glue layer 310 with a thickness of 0.6 mm to 0.8 mm, such as the thickness of the initial glue layer 310 is 0.55 mm, 0.6 mm or 0.65 mm. During the curing process, the initial adhesive layer 310 can be firmly bonded to the first panel 100. The initial adhesive layer 310 formed by curing is similar to a double-sided optical tape, which has double-sided adhesive properties, one of which is bonded to the first panel 100 (specifically, the bonding area), and the other is used for the subsequent second coating of liquid optical adhesive.

[0047] S20: Apply liquid optical adhesive to the adhesive coating area of ​​the initial adhesive layer 310 facing away from the first panel 100, wherein the adhesive coating area is located in the central area of ​​the initial adhesive layer 310, and its area is 1 / 2 to 4 / 5 of the area of ​​the bonding area, and the maximum thickness of the applied liquid optical adhesive is 0.05 mm to 0.25 mm. Figure 3 shown.

[0048] In step S20, the second glue coating of the bonding method is performed, that is, the liquid optical glue is coated on the surface of the initial glue layer 310, that is, after this step, there is uncured liquid optical glue 320 on the initial glue layer 310. The liquid optical glue coated for the second time does not cover the entire surface of the initial glue layer, but is only coated on the central area thereof, that is, the coated liquid optical glue leaves a distance from the edge of the initial glue layer 310, and the surface area of ​​the initial glue layer covered by it is 1 / 2 to 4 / 5 of the area of ​​the bonding area, such as 1 / 2, 3 / 5, 7 / 10 or 4 / 5, etc., and the thickness of the coated liquid optical glue is relatively small, and the maximum thickness is only 0.05 mm to 0.25 mm, such as 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.10 mm, 0.12 mm, 0.14 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.23 mm or 0.25 mm, etc.

[0049] S30: placing the second panel 200 on the side of the first panel 100 where the liquid optical adhesive is disposed, and pressing the second panel 200 so that the liquid optical adhesive applied in step S20 covers the initial adhesive layer 310, forming an uncured adhesive layer 320, and obtaining a semi-finished device, such as Figure 4 shown.

[0050] After the liquid optical adhesive is partially coated in step S20, the second panel 200 is placed on the first panel 100 coated with the liquid optical adhesive without curing treatment, that is, at this time, there is a cured initial adhesive layer 310 and uncured liquid optical adhesive 320 between the first panel 100 and the second panel 200, and a pressing force is applied to the second panel 200 and the first panel 100. The uncured liquid optical adhesive will flow from the middle to the edge under the action of pressure, so that the uncured liquid optical adhesive 320 will eventually cover the side of the initial adhesive layer 310 away from the first panel 100. At this time, the thickness of the overall adhesive layer formed by the initial adhesive layer 310 and the uncured liquid optical adhesive, that is, the uncured adhesive layer 320 is basically consistent everywhere.

[0051] S40: Defoaming the semi-finished device, and then performing a curing process to fully bond the first panel 100 and the second panel 200 through the optical adhesive layer to obtain a fully bonded display device, such as Figure 5 The initial adhesive layer 310 and the uncured adhesive layer 320 together form the optical adhesive layer 300 .

[0052] In this step, the glue layer after lamination is first defoamed and then cured. During the curing process, the uncured glue layer 320 is cured and fused with the initial glue layer 310 to form the optical glue layer 300. At the same time, the optical glue layer 300 is firmly bonded to the second panel 200. In this way, the first panel 100 and the second panel 200 are fully bonded through the optical glue layer 300. The curing process in this step is equivalent to high-temperature aging at the same time.

[0053] The liquid optical adhesive selected in the above step S10 is the same as that in step S20, that is, the first gluing process and the second gluing process are performed using the same liquid optical adhesive.

[0054] The full bonding method in the above embodiment, through the secondary glue coating process, is directly cured after the first full-area coating, and the thickness of the initial glue layer 310 formed is controlled to be 0.55mm-0.65mm. After the second partial coating, the first panel 100 and the second panel 200 are pressed together, and then cured after degassing treatment, and the area of ​​the second coating is controlled to be 1 / 2-4 / 5 of the area of ​​the bonding area, and the maximum thickness of the coated liquid optical glue is 0.05mm-0.25mm. In this way, although the glue coating process in the full bonding method is the first full-area coating, since it is directly cured without the lamination process, there are basically no bubbles in the initial glue layer 310 formed. Although the lamination process is passed after the second glue coating, the thickness of the glue layer is very thin, which is mainly used to achieve the bonding of the second panel. Therefore, basically no bubbles are generated during the lamination process, thereby increasing the yield rate of the full bonding process, improving the display effect of the finished display device, and improving its resolution and contrast performance. The cured initial adhesive layer 310 also functions as a double-sided optical adhesive tape, which can achieve a firm bond to the first panel 100. After that, by curing together with the second applied liquid optical adhesive, a firm bond is also formed with the second panel 200, thereby ensuring the reliability of the bonding between the first panel 100 and the second panel 200.

[0055] In some embodiments, in order to solve the problem of bubbles generated during lamination when the liquid optical glue is only applied once, some only apply the liquid optical glue in the middle area, but the amount of liquid optical glue applied is large and it has fluidity. Therefore, the flow of the liquid optical glue during lamination is difficult to control and the probability of back-bubbling is still very high; some directly apply a thinner optical glue layer only once, however, this process has too high manufacturing accuracy requirements for the first panel and the second panel, especially the flatness requirements, which is not suitable for mass production, and this process is also inevitably limited by the manufacturing process, resulting in bubbles in some areas during lamination. In the present invention, by controlling the thickness of the initial glue layer 310 formed by the first glue coating, the manufacturing accuracy of the first panel and the second panel can be compensated to a certain extent, thereby reducing the processing accuracy of the first panel and the second panel, and can further reduce or even avoid the problem of bubbles in the final display device.

[0056] At the same time, since the first and second coatings use the same liquid optical glue, even if the first coating solidifies into the initial glue layer 310, when the second coating solidifies, the second glue can be completely integrated with the initial glue layer 310 without causing stratification that affects the display effect.

[0057] It can be seen that the full bonding method of the display device of the present invention can reduce or even eliminate the anti-bubble phenomenon in the manufacture of the display device, improve the product yield, increase the display effect of the display device, and improve the performance such as resolution and contrast. This can also be clearly seen from the test data in Table 1 below, where samples 1 to 7 are display devices bonded by the bonding method of the present invention in batches, and comparative products 1 to comparative products 4 are display devices bonded by one-time gluing in batches. It can be clearly seen from the table that the maximum number of bubbles in the initial inspection of samples 1 to 7 is 3, and the maximum number of bubbles after high temperature is 1, and even completely defoamed, and the defective rate does not exceed 1%; while the defective rate of comparative products 1 to comparative products 4 exceeds 20%. The "number of bubbles in the initial inspection" in the table is the number of defective samples detected after the defoaming treatment in the above step S40 is performed; the "number of bubbles after high temperature" is the number of samples after the "number of bubbles in the initial inspection" is removed, and the remaining samples are subjected to the entire process of the above step S40, that is, the high temperature test is completed at the same time. , The number of samples detected.

[0058] Table 1

[0059] Sample quantity Initial inspection bubble quantity Bubble detection quantity after high temperature Bad ratio Sample 1 150 2 0 1％ Sample 2 200 2 0 1％ Sample 3 200 1 0 1％ Sample 4 200 1 0 1％ Sample 5 600 3 1 1％ Sample 6 600 2 1 1％ Sample 7 600 3 0 1％ Comparison product 1 350 66 37 29％ Comparison product 2 365 50 30 22％ Comparison product 3 85 7 14 25％ Comparison product 4 300 50 30 27％

[0060] Specifically, before step S10 , the first panel 100 and the second panel 200 may be pre-processed, such as cleaning, and then the first panel 100 is placed on a support table to support the first panel 100 .

[0061] In step S10, after the liquid optical adhesive is coated on the bonding area of ​​the first panel 100, the liquid optical adhesive can be substantially evenly covered on the first panel 100 by scraping, so that after the subsequent curing process, the thickness of the formed initial adhesive layer 310 is substantially uniform everywhere.

[0062] Specifically, the curing process of step S10 and step S40 can select the curing time and curing temperature according to the performance of the liquid glue. In a preferred embodiment, in step S10, the curing time of the curing process is 10 to 20 minutes, and the curing temperature is 60°C to 80°C, such as the curing time is 10 minutes, 12 minutes, 15 minutes, 16 minutes, 18 minutes or 20 minutes, and the curing temperature is 60°C, 65°C, 70°C, 75°C or 80°C. The curing process of step S10 adopts this process parameter range, which can not only ensure that the liquid optical glue on the first panel 100 is cured to form the initial glue layer 310, so that it is not easy to flow, but also increase the fusion of the initial glue layer 210 and the subsequent uncured glue layer 320 when they are cured together, further improving the display effect of the display device; and this parameter range can also ensure the firm bonding between the initial glue layer 310 and the first panel 100, thereby improving the reliability of the finished display device. More preferably, in step S10, the curing time of the curing process is 15 minutes and the curing temperature is 70° C., so as to further improve the display effect and reliability of the manufactured display device.

[0063] In step S20, liquid optical adhesive may be applied to the initial adhesive layer 310, and step S30 may be directly performed, that is, the second panel 200 is placed on the liquid optical adhesive and aligned with the first panel 100. In this manner, the liquid optical adhesive applied in step S20 may flow slowly to form an uncured adhesive layer 320 with a substantially uniform thickness as step S30 is placed.

[0064] In one embodiment, in step S20, liquid optical glue is first applied to the glue coating area, and then scraped. Preferably, in step S20, the liquid optical glue is applied by a liquid optical glue scraper so that the coverage area of ​​the formed glue film is 2 / 3 of the area of ​​the bonding area. In this way, the thickness of the formed glue film is basically uniform, and the thickness of the glue film is easy to control, so that the liquid optical glue placed between the second panel 200 can be basically uniform everywhere, so that during the lamination process, the occurrence of anti-bubble phenomenon is further reduced or even completely avoided, thereby better improving the yield rate and display effect of the display device. Among them, the coverage area of ​​the glue film is basically 2 / 3 of the area of ​​the bonding area, that is, 2 / 3 of the area covered by the initial glue layer 310 of the first panel 100, and the thickness of the glue film is controlled at 0.05mm to 0.25mm, and the thickness of the glue film after scraping is preferably 0.1mm. Of course, the glue film is still located in the middle area of ​​the first panel 100, that is, there is still a distance from the edge of the first panel 100.

[0065] In step S20, the thickness of the adhesive film formed by the applied liquid optical adhesive and the thickness of the initial adhesive layer are less than or equal to 0.8 mm, and the minimum distance between the edge of the adhesive film and the edge of the first panel is 8 mm to 15 mm. That is to say, in this embodiment, in step S20, when applying the liquid optical adhesive, the total thickness of the adhesive film and the initial adhesive layer is controlled to be the maximum, so that the total thickness does not exceed 0.8 mm. This control method can better control the thickness of the optical adhesive layer after the overall molding, as well as the fluidity of the liquid optical adhesive during the lamination in step S30, so as to further reduce or even completely avoid the occurrence of anti-bubble phenomenon during the lamination process, so that the molded optical adhesive layer is closer to the ideal state, and the yield rate and display effect of the display device are better improved. , such as Figure 3 As shown, the total thickness of the adhesive film and the initial adhesive layer is controlled to be less than or equal to 0.8 mm, such as the thickness can be 0.6 mm, 0.63 mm, 0.65 mm, 0.68 mm, 0.7 mm, 0.73 mm, 0.75 mm, 0.78 mm or 0.8 mm, and the minimum distance between the edge of the adhesive film and the edge of the first panel 100 is 8 mm to 15 mm, such as the minimum distance is 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm or 15 mm, and preferably, the distance between the edge of the adhesive film and the edge of the first panel 100 is substantially 10 mm.

[0066] The scraping in the above embodiment can be performed from one side of the liquid optical adhesive to the other side, or from the middle to the edge, and the latter is preferred.

[0067] Wherein, the liquid optical adhesive in step S10 and step S20 can be both OCR optical adhesive. Specifically, the viscosity of the liquid optical adhesive is 800mPa·s~1200Pa·sPa·s, and the shear strength and positive tensile strength after curing are both greater than or equal to 0.2MPa, such as the viscosity of the liquid optical adhesive is 800mPa·s, 900Pa·sPa·s, 1000Pa·sPa·s, 1100Pa·sPa·s or ~1200Pa·sPa·s, and the shear strength and positive tensile strength after curing can be any of the following values, such as 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa or 0.4MPa, etc. By preferably using liquid optical adhesive with such performance, the controllability of the liquid optical adhesive in the adhesive coating process can be ensured, reducing the workload of large amounts of adhesive cleaning in the later stage, and improving the reliability of bonding between the optical adhesive layer and the first panel 100 and the second panel 200. This can further reduce the anti-bubble problem in the full bonding method and increase the bonding force between the first panel 100 and the second panel 200.

[0068] Regardless of which of the above embodiments is adopted in step S10 and step S20, in the lamination of the second panel 200 and the first panel 100, in step S30, the lamination can be performed along the direction from the center to the edge, so that the first panel 100 and the second panel 200 are gradually and closely fitted from the center to the edge. Specifically, pressure can be applied to the central area of ​​the second panel 200 and the first panel 100 first, and then gradually applied to the edge, so that even if there are very few bubbles in the thinner liquid optical adhesive, the bubbles can be moved to the edge until they are discharged from between the first panel 100 and the second panel 200, thereby further reducing or even eliminating the bubbles in the optical adhesive layer 300, and improving the display effect of the display device.

[0069] It should be noted that in step S30, when placing the second panel 200, the second panel 200 can be moved along a direction substantially perpendicular to the first panel 100 (i.e., the thickness direction of the first panel 100), and the second panel 200 can be placed on the liquid optical adhesive. Of course, when placing the second panel 200, the second panel 200 also needs to be aligned with the first panel 100. The specific alignment method can adopt the alignment method of the prior art, such as through the positioning structure of the edge, or by respectively setting alignment marks on the first panel 100 and the second panel 200.

[0070] Specifically, in step S30, the pressing force in the pressing process is preferably 0.015Mpa to 0.025Mpa, such as 0.015Mpa, 0.018Mpa, 0.02Mpa, 0.022Mpa or 0.025Mpa. This pressing force can further avoid the generation of bubbles during the pressing process and can also avoid the problem of anti-bubbling in the later stage.

[0071] In step S40, the curing time in the curing process is 15 minutes to 20 minutes, the curing temperature is 70°C to 80°C, and the thickness of the optical adhesive layer formed by curing is less than or equal to 0.7 mm. For example, if the curing time is 15 minutes, 16 minutes, 18 minutes, 19 minutes or 20 minutes, and the curing temperature is 70°C, 72°C, 75°C, 78°C or 80°C, the thickness of the optical adhesive layer formed by curing can be 0.7 mm, 0.68 mm, 0.65 mm, 0.63 mm, 0.6 mm, etc. By adopting this range, the cured optical adhesive layer can be more uniform and firm, and the anti-bubble problem can be avoided in the later stage.

[0072] The present invention also provides a full bonding device for a display device, which can be used to perform the full bonding method described in any of the above embodiments, and the full bonding device includes a glue coating device, a curing device, a defoaming device and a pressing device. The glue coating device is used to perform the liquid glue coating process in step S10 and step S20, that is, the glue coating device is used in the above full bonding method to coat the liquid optical glue on the bonding area of ​​the first panel 100, so that the liquid optical glue covers the bonding area. The curing device is used to perform the curing process in step S10 and step S40, that is, the curing device is used in the above full bonding method to perform the curing process. The defoaming device is used to perform the defoaming treatment in step S40 to further eliminate bubbles that may exist in the optical adhesive layer before pressing with the second panel 200. The laminating device is used to perform the laminating process in step S30, that is, in the above-mentioned laminating method, the second panel 200 is placed on the side of the first panel 100 where the liquid optical glue is set, and pressed so that the liquid optical glue applied in step S20 covers the initial glue layer 310, forming an uncured glue layer 320, and obtaining a semi-finished device.

[0073] The present invention also provides a display device, which can be a car instrument screen, a central control screen, or a display screen on an intelligent display terminal, such as a mobile phone screen. Figure 5 As shown, the display device includes a first panel 100 and a second panel 200. The first panel 100 and the second panel 200 are fully bonded via an optical adhesive layer 300, and the first panel and the second panel are bonded via the full bonding method described in any of the above embodiments.

[0074] Among them, the thickness of the optical adhesive layer is less than or equal to 0.7mm, the number of bubbles per unit area in the bubble test of the display device is less than 2, the high temperature resistance reaches above 85°C, and the humidity resistance reaches above 85% rh.

[0075] Regardless of the type of display device, the first panel 100 and the second panel 200 can both be flat panels or curved panels. In other words, the above-mentioned full bonding method can be applied to both curved screen display devices and flat screen display devices.

[0076] In one embodiment, the first panel 100 may be a display panel, and the second panel 200 may be a glass cover. The display device may be a non-touch display device or a touch display device. When it is a non-touch display device, the display panel includes a display screen, that is, a non-touch display panel; when the display device is a touch display device, the display panel includes a display screen and a touch screen (or a touch film), that is, the display panel is a touch display panel. When the display device is an instrument screen, the first panel is the display panel of the instrument screen, and the second panel is the glass cover of the instrument screen.

[0077] It should be noted that the use of step numbers (letters or numbers) to refer to certain specific method steps in the present invention is only for the purpose of convenience and brevity of description, and is by no means intended to limit the order of these method steps by letters or numbers. Those skilled in the art will understand that the order of the relevant method steps should be determined by the technology itself and should not be inappropriately limited by the existence of step numbers. Those skilled in the art can determine various permissible and reasonable step orders based on the technology itself.

[0078] Those skilled in the art will appreciate that, without conflict, the above-mentioned preferred solutions can be freely combined and superimposed.

[0079] It should be understood that the above-mentioned embodiments are merely illustrative and not restrictive. Without departing from the basic principles of the present invention, various obvious or equivalent modifications or substitutions that can be made by those skilled in the art to the above-mentioned details will all be included in the scope of the claims of the present invention.

Claims

1. A method for fully bonding a display device, wherein the display device comprises a first panel and a second panel, wherein the first panel and the second panel are fully bonded by an optical adhesive layer; characterized in that: The full lamination method comprises the steps of: S10: applying liquid optical adhesive to the bonding area of ​​the first panel so that the liquid optical adhesive covers the bonding area, and then forming an initial adhesive layer on one side of the first panel through a curing process; wherein the thickness of the initial adhesive layer is 0.55 mm to 0.65 mm; S20: applying liquid optical adhesive to the adhesive coating area on the side of the initial adhesive layer facing away from the first panel, wherein the adhesive coating area is located in the central area of ​​the initial adhesive layer, and its area is 1 / 2 to 4 / 5 of the area of ​​the bonding area, and the maximum thickness of the applied liquid optical adhesive is 0.05 mm to 0.25 mm; S30: placing the second panel on the side of the first panel where the liquid optical adhesive is disposed, and pressing the panel together so that the liquid optical adhesive applied in step S20 covers the initial adhesive layer, forming an uncured adhesive layer, and obtaining a semi-finished device; S40: performing a defoaming treatment on the semi-finished device, and then fully bonding the first panel and the second panel through the optical adhesive layer through a curing process to obtain a fully bonded display device; wherein the initial adhesive layer and the uncured adhesive layer jointly form the optical adhesive layer during the curing process; The liquid optical adhesive selected in step S10 is the same as that selected in step S20.

2. The full lamination method according to claim 1, characterized in that: In the step S10, the curing time of the curing process is 10 to 20 minutes, and the curing temperature is 60° C. to 80° C.

3. The full lamination method according to claim 2, characterized in that: In the step S10, the curing time of the curing process is 15 minutes and the curing temperature is 70°C.

4. The full lamination method according to claim 1, characterized in that: In the step S20, the liquid optical adhesive is coated by a liquid optical adhesive coating knife so that the coverage area of ​​the formed adhesive film is 2 / 3 of the area of ​​the bonding area.

5. The full lamination method according to claim 1, characterized in that: In the step S20, the maximum thickness of the adhesive film formed by the applied liquid optical adhesive and the initial adhesive layer is less than or equal to 0.8 mm, and the minimum distance between the edge of the adhesive film and the edge of the first panel is 8 mm to 15 mm.

6. The full lamination method according to claim 1, characterized in that: The viscosity of the liquid optical adhesive in step S10 and step S20 is 800 mPa·s to 1200 Pa·sPa·s, and the shear strength and positive tensile strength after curing are both greater than or equal to 0.2 MPa.

7. The full lamination method according to claim 1, characterized in that: In the step S30, the pressing is performed along a direction from the center to the edge, so that the first panel and the second panel are gradually and closely attached to each other from the center to the edge.

8. The full lamination method according to claim 1, characterized in that: In the step S30, the pressing force in the pressing process is 0.015Mpa to 0.025Mpa; in the step S40, the curing time in the curing process is 15 minutes to 20 minutes, the curing temperature is 70°C to 80°C, and the thickness of the optical adhesive layer formed by curing is less than or equal to 0.7mm.

9. A full bonding device for a display device, used for executing the full bonding method according to any one of claims 1 to 7; the display device comprises a first panel and a second panel, the first panel and the second panel are fully bonded by an optical adhesive layer; characterized in that: The full lamination equipment comprises: A glue coating device, used to perform the process of coating liquid glue in step S10 and step S20; A curing device, used to perform the curing process in step S10 and step S40; A defoaming device, used to perform the defoaming process in step S40; The pressing device is used to perform the pressing process in step S30.

10. A display device, characterized in that: The display device comprises a first panel and a second panel, the first panel and the second panel are fully bonded by an optical adhesive layer, and the two are bonded by the full bonding method according to any one of claims 1 to 9; The thickness of the optical adhesive layer is less than or equal to 0.7 mm, the number of bubbles per unit area in the bubble test of the display device is less than 2, the high temperature resistance reaches above 85° C., and the humidity resistance reaches above 85% rh.

11. The display device according to claim 10, characterized in that: The display device includes an instrument screen, the first panel is a display panel of the instrument screen, and the second panel is a glass cover of the instrument screen.

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