Adhesive layer structure and method for fabricating a flexible panel

Abstract

An adhesive layer structure for fabricating a flexible panel includes a first adhesive film, a second adhesive film, plural buffer structures and a filler material. The first and second adhesive films are disposed against each other. The buffer structures are disposed between the first and second adhesive films. The filler material is between the first and second adhesive films, and the filler material fills gaps between the buffer structures.

Description

Technical Field

[0001] This disclosure relates to an adhesive layer structure and a method for manufacturing a flexible panel, and more particularly to an adhesive layer structure that can reduce panel warpage and a method for manufacturing a flexible panel. Prior Technology

[0002] With the development of display technology, display panels are widely used in various electronic products, such as televisions, mobile phones, tablets, smartwatches, electronic signage, and electronic tags. However, during the panel manufacturing process, applying external pressure can easily cause the panel to warp, leading to a decrease in production yield. Summary of the Invention

[0003] The purpose of this invention is to provide an adhesive layer structure and a method for manufacturing a flexible panel, which features a special design in terms of heat-deformable materials and support structures. During panel manufacturing, when external pressure is applied, the adhesive layer structure provides sufficient support to reduce surface unevenness. This reduces the warpage of the flexible panel, maintains good flatness, and thus improves production yield.

[0004] To achieve the above objectives, this invention proposes an adhesive layer structure for manufacturing flexible panels, comprising a first adhesive film, a second adhesive film, multiple cushioning structures, and a filler. The first and second adhesive films are disposed opposite to each other. The cushioning structures are disposed between the first and second adhesive films. The filler is located between the first and second adhesive films, filling the gaps between the cushioning structures.

[0005] According to one embodiment of the present invention, the heat deflection temperature (HDT) of the filler is less than the heat deflection temperature of either the first film or the second film.

[0006] According to another embodiment of the present invention, the filler is a polymer with a heat distortion temperature between 60°C and 140°C.

[0007] According to another embodiment of the present invention, the first adhesive film and the second adhesive film are ultraviolet light dissociation adhesives or thermal dissociation adhesives.

[0008] According to another embodiment of the present invention, the cross-sectional shape of each buffer structure is semi-circular, semi-elliptical, trapezoidal, rectangular, semi-circular shell with a central hollow, or semi-elliptical shell with a central hollow.

[0009] According to another embodiment of the present invention, the buffer structure includes a plurality of first buffer structures and a plurality of second buffer structures, wherein the first buffer structures and the second buffer structures are arranged alternately.

[0010] In accordance with the above objectives, the present invention provides a method for manufacturing a flexible panel, comprising: disposing a first flexible substrate on a first carrier plate via the aforementioned adhesive layer structure; forming a first element layer on the first flexible substrate; and separating the first flexible substrate from the first carrier plate.

[0011] According to another embodiment of the present invention, a second flexible substrate is disposed on a second carrier plate via the above-described adhesive layer structure; a second element layer is formed on the second flexible substrate; the first carrier plate and the second carrier plate are positioned opposite each other to assemble the first flexible substrate and the second flexible substrate, wherein the first element layer and the second element layer are located between the first flexible substrate and the second flexible substrate; and the second flexible substrate is separated from the second carrier plate.

[0012] According to another embodiment of the present invention, the step of forming the first element layer includes a process at a temperature greater than or equal to 60 degrees Celsius.

[0013] According to another embodiment of the present invention, a cladding layer is formed on a first flexible substrate, wherein the step of forming the cladding layer is prior to the step of forming the first element layer, and the step of forming the cladding layer includes a process at a temperature greater than or equal to 60 degrees Celsius. Simple Explanation of the Diagram

[0014] To gain a more complete understanding of the embodiments and their advantages, the following description, taken in conjunction with the accompanying drawings, is provided, wherein: Figure 1 is a schematic diagram of an adhesive layer structure according to an embodiment of the present disclosure; Figure 2 is a schematic diagram of a buffer structure according to a partial embodiment of this disclosure; Figure 3 is a schematic diagram of an adhesive layer structure according to another embodiment of the present disclosure; Figure 4 is a flowchart of a method for manufacturing a flexible panel according to some embodiments of the present disclosure; Figures 5A to 5G are cross-sectional views of a flexible panel according to an embodiment of the present disclosure at various stages of the manufacturing process; Figure 6A is a schematic diagram showing the shrinkage of the adhesive layer structure towards the film surface according to a comparative embodiment of the present disclosure; Figure 6B is a schematic diagram showing the tapering of the adhesive layer structure toward the carrier plate according to a comparative embodiment of the present disclosure; Figure 7A is a schematic diagram of stress dissipation in the adhesive layer structure in the direction of film surface contraction according to a partial embodiment of this disclosure; and Figure 7B is a schematic diagram of stress dissipation in the shrinkage direction of the adhesive layer structure towards the carrier plate according to a partial embodiment of this disclosure. Implementation

[0015] The embodiments disclosed herein are discussed in detail below. However, it will be understood that the embodiments provide many applicable concepts that can be implemented in a wide variety of specific situations. The discussed and disclosed embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure.

[0016] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the claims. Unless otherwise limited, the singular forms of "a" or "the" may also be used to denote the plural forms.

[0017] It is understood that although terms such as "first," "second," etc., may be used in this article to describe various features, these terms should not limit these features. These terms are only used to distinguish one feature from another.

[0018] The use of spatial relativity is intended to describe the different orientations of a component during use or operation, and is not limited to the orientation shown in the diagram. Components may also be oriented in other ways (rotated 90 degrees or in other directions), and the spatial relativity described here can be interpreted in the same way.

[0019] For the sake of simplicity and clarity, element symbols and / or letters may be repeated in various embodiments herein, but this does not imply a causal relationship between the various embodiments and / or configurations discussed. Furthermore, for the sake of simplicity and clarity in illustrating technical features, elements in the drawings are not drawn to scale, and the dimensions of each element may be arbitrarily increased or decreased.

[0020] Please refer to Figures 1 and 2 together. Figure 1 is a schematic diagram of an adhesive layer structure 100 according to an embodiment of the present disclosure, and Figure 2 is a schematic diagram of a buffer structure 120 according to a partial embodiment of the present disclosure. In some embodiments, the adhesive layer structure 100 may include an adhesive film 110, a buffer structure 120, a filler 130, and an adhesive film 140. In some embodiments, the adhesive layer structure 100 may be applied in the fabrication of flexible privacy panels or other types of flexible panels (e.g., flexible display panels or flexible touch panels).

[0021] In some embodiments, films 110 and 140 may be made of any suitable material, and the materials of films 110 and 140 may be the same or different from each other. For example, in some embodiments, films 110 and 140 may both be UV-dissociative adhesives, thermal dissociative adhesives, combinations thereof, or other types of films. In another embodiment, one of films 110 and 140 may be a UV-dissociative adhesive and a thermal dissociative adhesive, respectively. In this embodiment, films 110 and 140 may be disposed opposite to each other and overlap each other along direction D1. Unless otherwise specified below, the overlap relationship between the two components is defined by direction D1, and the overlap direction will not be described again.

[0022] In some embodiments, a buffer structure 120 may be disposed between the adhesive film 110 and the adhesive film 140, wherein the buffer structure 120 may include a plurality of first buffer structures 122 and a plurality of second buffer structures 124. For example, in some embodiments, the first buffer structures 122 and the second buffer structures 124 of the buffer structure 120 may be formed on the surface 110A of the adhesive film 110 and the surface 140A of the adhesive film 140, respectively, and the first buffer structures 122 and the second buffer structures 124 of the buffer structure 120 are staggered in the direction D1. In this way, the buffer structure 120 can provide pressure support during the manufacturing process of the flexible panel, allowing the surface of the adhesive layer structure 100 to be flat, thereby improving the flatness of subsequent processes. Furthermore, by reducing stress and improving surface flatness through the buffer structure 120, the covering layer 330 (see subsequent Figures 5A to 5F) can be selectively omitted. This reduces process complexity and light refraction, thereby improving production efficiency, light penetration, and display performance.

[0023] Furthermore, the shapes of the first buffer structure 122 and the second buffer structure 124 of the buffer structure 120 can be changed according to functional requirements. For example, in some embodiments, the cross-sectional shape of the first buffer structure 122 and the second buffer structure 124 of the buffer structure 120 can be semi-circular, semi-elliptical, trapezoidal, rectangular, or other suitable shapes. In another embodiment, the cross-sectional shape of the first buffer structure 122 and the second buffer structure 124 of the buffer structure 120 can be a semi-circular shell shape, a semi-elliptical shell shape, or other suitable shapes with a central hollow. Therefore, when pressure is released, the pressure can be buffered through the central hollow of the first buffer structure 122 and the second buffer structure 124 of the buffer structure 120, thereby reducing the amount of deformation.

[0024] In some embodiments, filler 130 may be a polymer with a heat deflection temperature (HDT) lower than that of either film 110 or film 140. In this embodiment, the HDT of filler 130 may be the temperature at which a load of 0.455 MPa or 1.82 MPa is placed at the center of a standard specimen using the ASTM D648 test method, and the temperature is increased at a rate of 2 degrees Celsius per minute until the specimen deforms by 0.25 mm. For example, in some embodiments, the filler 130 may be a polymer with a heat distortion temperature between 60 degrees Celsius and 140 degrees Celsius, such as polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polycarbonate (PC), polypropylene (PP), polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene (ABS), cellulose acetate (CA), cellulose acetate butylate (CAB), cellulose acetate propionate (CAP), styrene-acrylonitrile plastic (SAN), polycyclohexylenedimethylene terephthalate glycol (PCTG), and polycyclohexylenedimethylene terephthalate. acid; PCTA), the above combinations, or other similar polymers.

[0025] Furthermore, in this embodiment, the filler 130 may be located between the adhesive film 110 and the adhesive film 140, filling the gap between the first buffer structure 122 and the second buffer structure 124 of the buffer structure 120. When heated to its heat distortion temperature, the filler 130 will be in a deformable state, forming a buffer layer inside the adhesive layer structure 100 to counteract stress. Thus, the adhesive film 110, the buffer structure 120, the filler 130, and the adhesive film 140 can enable the adhesive layer structure 100 to form, for example, a double-sided adhesive layer structure.

[0026] Please also refer to Figure 3, which is a schematic diagram of an adhesive layer structure 100 according to another embodiment of the present disclosure. The difference between the adhesive layer structure 100 in Figure 3 and the adhesive layer structure 100 in Figure 1 is that the adhesive layer structure 100 in Figure 3 may further include a support film structure 150, wherein the support film structure 150 may include a first support film 152 and a second support film 154. The first support film 152 and the second support film 154 of the support film structure 150 may be made of any suitable material. For example, in this embodiment, the first support film 152 and the second support film 154 of the support film structure 150 may be polyethylene terephthalate. The first support film 152 and the second support film 154 of the support film structure 150 may be disposed between the adhesive film 110 and the adhesive film 140. For example, in this embodiment, the first support film 152 of the support film structure 150 may be disposed on the surface 110A of the adhesive film 110. The second support membrane 154 of the support membrane structure 150 may be disposed on the surface 140A of the adhesive membrane 140. The first buffer structure 122 and the second buffer structure 124 of the buffer structure 120 are respectively disposed on the surface 152A of the first support membrane 152 facing away from the adhesive membrane 110 and the surface 154A of the second support membrane 154 facing away from the adhesive membrane 140.

[0027] For example, in this embodiment, the first buffer structure 122 and the second buffer structure 124 of the buffer structure 120 can first be made into microstructure molds by photolithography injection molding (LIGA). Then, using a roll-to-roll transmission method as the basic framework, a composite roller printing system of ultraviolet curing and thermoforming is used to transfer the microstructures on the metal roller mold core to the surface 110A of the adhesive film 110 and the surface 140A of the adhesive film 140 in the embodiment of FIG1, or to the surface 152A of the first support film 152 of the support film structure 150 opposite to the adhesive film 110 and the surface 154A of the second support film 154 of the support film structure 150 opposite to the adhesive film 140 in the embodiment of FIG3. In some embodiments, the first buffer structure 122 and the second buffer structure 124 of the buffer structure 120 are made of the same material as the first support film 152 and the second support film 154 of the support film structure 150, such as polyethylene terephthalate.

[0028] Please refer to Figures 4 and 5A to 5G. Figure 4 is a flowchart of a method 200 for manufacturing a flexible panel P1 according to a partial embodiment of the present disclosure. Figures 5A to 5G are cross-sectional views of a flexible panel P1 according to an embodiment of the present disclosure at various stages of the manufacturing process. Manufacturing method 200 includes steps S210 to S270. It should be understood that additional steps may be added before, during, and after steps S210 to S270, and for another partial embodiment of the method, some of the steps mentioned below may be replaced or omitted. The order of steps / procedures may be changed.

[0029] The following example illustrates the application of the adhesive layer structure 100 of the present invention to the fabrication of a flexible privacy panel. However, it should be noted that this disclosure is not limited thereto. The adhesive layer structure 100 of the present invention can also be applied to the fabrication of other types of flexible panels P1 (e.g., flexible display panels or flexible touch panels). Furthermore, the adhesive layer structure 100 in the following figures may be the adhesive layer structure 100 of FIG. 1 or the adhesive layer structure 100 of FIG. 3 (the support film structure 150 of the adhesive layer structure 100 of FIG. 3 is omitted).

[0030] Referring to Figure 5A, in step S210 of manufacturing method 200, the flexible substrate 320 is disposed on the carrier plate 310 via the adhesive layer structure 100, wherein the carrier plate 310 may be a rigid carrier plate. For example, in some embodiments, the adhesive layer structure 100 may be provided, and the adhesive film 110 and adhesive film 140 of the adhesive layer structure 100 may be respectively attached to the surfaces of the carrier plate 310 and the flexible substrate 320, but this is not a limitation. In other embodiments, the adhesive layer structure 100 may be fabricated on the carrier plate 310, and then the flexible substrate 320 may be attached to the surface 140B of the adhesive film 140 of the adhesive layer structure 100. For example, the adhesive film 110 of the adhesive layer structure 100 may be attached to the carrier plate 310 by an attachment process. In another embodiment, the adhesive film 110 of the adhesive layer structure 100 can be disposed on the carrier plate 310 by a coating process, wherein the coating process may include slit coating, spin coating, or other suitable coating processes. Next, a first buffer structure 122 of the buffer structure 120 is formed on the adhesive film 110. Next, a filler 130 is disposed on the first buffer structure 122 of the buffer structure 120. Next, an adhesive film 140 having a second buffer structure 124 of the buffer structure 120 is disposed on the filler 130. Next, the flexible substrate 320 is attached to the adhesive film 140.

[0031] Furthermore, when the adhesive film 110 of the adhesive layer structure 100 is spin-coated and attached to the carrier plate 310, a photoresist removal process can be selectively performed between steps S210 and S220. For example, in some embodiments, photoresist removal materials such as propylene glycol methyl ether acetate (PGMEA), potassium hydroxide, tetramethylammonium hydroxide (TMAH), and sodium hydroxide can be used to remove the photoresist.

[0032] Next, fabrication method 200 proceeds to step S220. Referring to FIG5B, a cladding layer 330 and a component layer 340 are formed on the flexible substrate 320. For example, in this embodiment, the step of forming the cladding layer 330 precedes the step of forming the component layer 340, and at least one of the steps of forming the cladding layer 330 and forming the component layer 340 may include a process at a temperature greater than or equal to 60°C. For example, in some embodiments, the material of the cladding layer 330 may be a transparent photoresist material (e.g., but not limited to, photosensitive resin materials), but is not limited thereto. The cladding layer 330 may be formed on the flexible substrate 320 by processes such as spin coating, exposure, development, and curing, but is not limited thereto. The cladding layer 330 may serve as a planarization layer, allowing the component layer 340 to be formed on the planar surface of the cladding layer 330. As shown in Figure 5B, the coating layer 330 covers the flexible substrate 320 and the adhesive layer structure 100, and wraps the sides of the flexible substrate 320 and the adhesive layer structure 100. Therefore, it can protect the flexible substrate 320 and the adhesive layer structure 100 from the influence of chemical agents (such as chemical corrosion) in subsequent processes. In other words, the coating layer 330 can also be used as a chemical resistance layer.

[0033] Next, element layer 340 is formed on cladding layer 330. For example, in some embodiments, element layer 340 may be a privacy electrode layer, wherein element layer 340 may contain a transparent conductive material, such as indium tin oxide (ITO), indium zinc oxide (IZO), antimony tin oxide (ATO), fluorine tin oxide (FTO), tin oxide, zinc oxide, graphene, combinations thereof, or other similar materials. Element layer 340 may be formed by, for example, physical vapor deposition (PVD), chemical vapor deposition (CVD), evaporation, sputtering, or other suitable deposition methods. In addition, lithography and etching processes may be selectively performed to pattern element layer 340. This forms structure S1.

[0034] Next, the fabrication method 200 proceeds to step S230. Referring to FIG5C, in step S230, the flexible substrate 520 is disposed on the carrier plate 510 via the adhesive layer structure 400, wherein the carrier plate 510 may be a rigid carrier plate. It is worth noting that the adhesive layer structure 400 may be substantially the same as the adhesive layer structure 100. Therefore, the adhesive film 410, the buffer structure 420, the filler 430, and the adhesive film 440 of the adhesive layer structure 400 may be the same as the adhesive film 110, the buffer structure 120, the filler 130, and the adhesive film 140 of the adhesive layer structure 100, respectively, and will not be described again here. In addition, in some embodiments, the adhesive layer structure 400 may also include the support film structure 150 of FIG3. For example, in some embodiments, the adhesive layer structure 400 may be provided, and the adhesive film 410 and the adhesive film 440 of the adhesive layer structure 400 may be attached to the surfaces of the carrier plate 510 and the flexible substrate 520, respectively, but this is not a limitation. In other embodiments, the adhesive layer structure 400 can be fabricated on a carrier plate 510, and then the flexible substrate 520 can be attached to the surface 440A of the adhesive film 440 of the adhesive layer structure 400. For example, the adhesive film 410 of the adhesive layer structure 400 can be attached to the carrier plate 510 by an attachment process. In another embodiment, the adhesive film 410 of the adhesive layer structure 400 can be disposed on the carrier plate 510 by a coating process, wherein the coating process may include slot coating, spin coating, a combination of the above, or other similar coating processes. Next, a first buffer structure 422 of the buffer structure 420 is formed on the adhesive film 410. Next, a filler 430 is disposed on the first buffer structure 422 of the buffer structure 420. Next, the adhesive film 440 having a second buffer structure 424 of the buffer structure 420 is attached to the filler 430. Next, the flexible substrate 520 is attached to the adhesive film 440.

[0035] Furthermore, when the adhesive film 410 of the adhesive layer structure 400 is spin-coated and attached to the carrier plate 510, a photoresist removal process can be selectively performed between steps S230 and S240. For example, in some embodiments, photoresist removal materials such as propylene glycol methyl ether acetate, potassium hydroxide, tetramethylammonium hydroxide, and sodium hydroxide can be used to remove the photoresist.

[0036] Next, fabrication method 200 proceeds to step S240. Referring to FIG. 5D, a cladding layer 530 and a component layer 540 are formed on the flexible substrate 520. For example, in this embodiment, the step of forming the cladding layer 530 precedes the step of forming the component layer 540, and at least one of the steps of forming the cladding layer 530 and forming the component layer 540 may include a process at a temperature greater than or equal to 60°C. For example, in some embodiments, the material of the cladding layer 530 may include a transparent photoresist material (e.g., but not limited to, photosensitive resin materials), but is not limited thereto. The cladding layer 530 may be formed on the flexible substrate 520 by spin coating, exposure, development, curing, a combination of the above, or other similar processes, but is not limited thereto. The cladding layer 530 may serve as a planarization layer, allowing the component layer 540 to be formed on the planar surface of the cladding layer 530. As shown in Figure 5D, the coating layer 530 covers the flexible substrate 520 and the adhesive layer structure 400, and wraps the sides of the flexible substrate 520 and the adhesive layer structure 400. Therefore, it can protect the flexible substrate 520 and the adhesive layer structure 400 from the influence of chemical agents (such as chemical corrosion) in subsequent processes. In other words, the coating layer 530 can also be used as a chemical resistance layer.

[0037] Next, element layer 540 is formed on cladding layer 530. For example, in some embodiments, element layer 540 may be a privacy electrode layer, wherein element layer 540 may comprise a transparent conductive material, such as indium tin oxide, indium zinc oxide, tin oxide, fluorine tin oxide, tin oxide, zinc oxide, graphene, combinations thereof, or other similar materials. Element layer 540 may be formed by deposition methods such as physical vapor deposition, chemical vapor deposition, evaporation, sputtering, combinations thereof, or other similar deposition methods. This forms structure S2.

[0038] Next, manufacturing method 200 proceeds to step S250. Referring to FIG5E, carrier plate 310 and carrier plate 510 are positioned opposite each other to assemble flexible substrate 320 and flexible substrate 520, wherein element layer 340 and element layer 540 are located between flexible substrate 320 and flexible substrate 520, and display medium layer 640 (e.g., liquid crystal layer) is located between element layer 340 and element layer 540. For example, in this embodiment, structure S1 and structure S2 may be arranged opposite each other along direction D1. Next, a frame adhesive 620 is formed on one of flexible substrate 320 and flexible substrate 520, and liquid crystal is injected into the area surrounded by frame adhesive 620 to form display medium layer 640. Next, structures S1 and S2 are assembled together to form a flexible panel P1, wherein the flexible panel P1 includes a flexible substrate 320, a cladding layer 330, a component layer 340, a frame adhesive 620, a display medium layer 640, a component layer 540, a cladding layer 530, and a flexible substrate 520.

[0039] Next, the fabrication method 200 proceeds to step S260. Referring to FIG5F, the flexible substrate 520 is separated from the carrier 510. For example, in this embodiment, the carrier 510 can be removed by laser peeling, mechanical peeling, thermal dissociation, ultraviolet peeling, a combination of the above, or other similar processes to peel the carrier 510, part of the coating layer 530, and the adhesive layer structure 400 from the adhesive film 440 of the adhesive layer structure 400 facing the surface 440A of the flexible substrate 520 (that is, to separate the carrier 510 from the flexible substrate 520).

[0040] Next, the fabrication method 200 proceeds to step S270. Referring to FIG5G, the flexible substrate 320 is separated from the carrier plate 310 to form the flexible panel P1. For example, in this embodiment, the carrier plate 310 can be removed by laser peeling, mechanical peeling, thermal dissociation, ultraviolet peeling, a combination of the above or other similar processes, to peel the carrier plate 310, part of the coating layer 330 and the adhesive layer structure 100 from the adhesive film 140 of the adhesive layer structure 100 facing the surface 140B of the flexible substrate 320 (that is, to separate the carrier plate 310 from the flexible substrate 320) to obtain the flexible panel P1.

[0041] Please refer to Figures 6A, 6B, 7A, and 7B. Figure 6A is a schematic diagram of the adhesive layer structure 100” shrinking towards the film surface according to a comparative embodiment of this disclosure. Figure 6B is a schematic diagram of the adhesive layer structure 100” shrinking towards the carrier plate according to a comparative embodiment of this disclosure. Figure 7A is a schematic diagram of stress dissipation during the shrinkage of the adhesive layer structure 100” towards the film surface according to a partial embodiment of this disclosure. Figure 7B is a schematic diagram of stress dissipation during the shrinkage of the adhesive layer structure 100” towards the carrier plate according to a partial embodiment of this disclosure. It should be noted that the main difference between the adhesive layer structure 100” of the comparative embodiment in Figures 6A and 6B and the adhesive layer structure 100” of the embodiment of the present invention in Figures 7A and 7B is that the adhesive layer structure 100” does not include the buffer structure 120 and the filler material 130. In the manufacturing process of the flexible panel P1, different materials in the flexible panel P1 may experience different degrees of thermal shrinkage or expansion due to their different properties, thereby superimposing different total stress directions. For example, in some embodiments, after forming the coating layer 330, a selective baking process at approximately 85°C or 100°C may be performed to generate stress F1 or stress F2. In another embodiment, when forming the element layers 340 / 540, a patterning process (e.g., a high-temperature photolithography process) may be selectively performed to generate stress F1 or stress F2. Therefore, only the stacked structure S3 of the carrier 310, adhesive layer structure 100, flexible substrate 320, and coating layer 330 is shown in FIG. 7A and FIG. 7B, and only the stacked structure S3” of the carrier 310, adhesive layer structure 100”, flexible substrate 320, and coating layer 330 is shown in FIG. 6A and FIG. 6B to illustrate the difference between the adhesive layer structure 100 of the present invention and the adhesive layer structure in the prior art after performing a high-temperature process (e.g., a baking process performed after coating layer 330 is applied).

[0042] Please refer to Figures 6A and 7A together. As shown in Figure 6A, the adhesive layer structure 100” includes an adhesive film 110”, and the adhesive film 110” is tightly bonded to the carrier plate 310. Therefore, when the shrinkage rate of the adhesive film 110” is greater than the shrinkage rate of the carrier plate 310, the adhesive layer structure 100” and the carrier plate 310 will warp as a whole towards the film surface (i.e., warp towards the flexible substrate 320 and the coating layer 330). As a result, when the coating layer 330 is coated and undergoes post-bake, it is affected by the curling of the adhesive layer structure 100” and the carrier plate 310 during the baking and hardening process. The surfaces of the coating layer 330 are squeezed against each other, resulting in poor surface flatness of the coating layer 330. As shown in Figure 7A, in an embodiment of the present invention, when the stacked structure S3 warps in the direction of film shrinkage under stress F1 (for example, the carrier plate 310 and the adhesive film 110 bend towards the surface 110A of the adhesive film 110, wherein the shrinkage rate of the adhesive film 110 is greater than that of the carrier plate 310), since the filler 130 separates the adhesive film 110 and the adhesive film 140, the adhesive film 140 is not affected by the adhesive film 110 when the adhesive film 110 shrinks due to heat. The filler 130 forms a buffer layer inside the adhesive layer structure 100 / 400 to offset part of the stress F1. Furthermore, since the adhesive film 140 is not connected to the carrier plate 310, the adhesive film 140 only shrinks horizontally, allowing the adhesive film 140, the flexible substrate 320, and the coating layer 330 to remain flat, thereby preventing the coating layer 330 from being compressed. In this way, the coating layer 330 can maintain good flatness.

[0043] Please refer to Figures 6B and 7B. As shown in Figure 6B, when the shrinkage rate of the adhesive film 110” is less than that of the carrier plate 310, the adhesive layer structure 100” and the carrier plate 310 as a whole will warp towards the carrier plate 310 (i.e., warp towards the direction opposite to the adhesive layer structure 100” of the carrier plate 310), causing the coating layer 330 to be applied after hard baking (post-coating). During baking and hardening, the coating layer 330 is affected by the curling of the adhesive layer structure 100” and the carrier plate 310. This causes lateral stretching of the adhesive layer structure 100” and the carrier plate 310, resulting in surface indentations or holes in the coating layer 330, leading to poor surface flatness. As shown in Figure 7B, in another embodiment, when the stacked structure S3 is subjected to stress F2 and warps in the direction of contraction towards the carrier plate (for example, the carrier plate 310 and the adhesive film 110 bend towards the surface 110B of the adhesive film 110, where the shrinkage rate of the adhesive film 110 is less than that of the carrier plate 310), Because the filler 130 separates the adhesive film 110 and the adhesive film 140, the adhesive film 140 is not affected by the adhesive film 110 when it shrinks due to heat. The filler 130 forms a buffer layer within the adhesive layer structure 100 / 400 to offset part of the stress F2. Furthermore, since the adhesive film 140 is not connected to the carrier plate 310, it is only stretched horizontally, allowing the adhesive film 140, the flexible substrate 320, and the coating layer 330 to remain flat. This prevents the coating layer 330 from being stretched and causing grooves or pits. Thus, the coating layer 330 maintains good flatness.

[0044] In summary, the adhesive layer structure and flexible panel manufacturing method proposed in this invention feature a unique design in terms of heat-deformable materials and support structures. During panel manufacturing, when external pressure is applied, the adhesive layer structure provides sufficient support to reduce surface unevenness. This reduces the warpage of the flexible panel, maintains good flatness, and ultimately improves production yield.

[0045] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0046] 100, 100", 400: Adhesive layer structure 110, 110", 140, 410, 440: Adhesive film 110A, 110B, 140A, 140B, 152A, 154A, 440A: Surface 120, 420: Buffer structure 122, 422: First buffer structure 124, 424: Second buffer structure 130, 430: Filler material 150: Supporting membrane structure 152: First support membrane 154: Second support membrane 200: Method 310, 510: Carrier board 320, 520: Flexible substrate 330, 530: Covering layer 340, 540: Component layer 620: Frame adhesive 640: Display media layer D1: Direction F1, F2: Stress P1: Flexible panel S1-S3,S3”: Structure S210-S270: Steps

Claims

1. An adhesive layer structure for manufacturing a flexible panel, comprising: a first adhesive film and a second adhesive film disposed opposite to each other, wherein the first adhesive film and the second adhesive film are UV-dissociating adhesives or thermally dissociating adhesives; a plurality of buffer structures disposed between the first adhesive film and the second adhesive film; and a filler material located between the first adhesive film and the second adhesive film, the filler material filling the gaps between the buffer structures.

2. The adhesive layer structure as claimed in claim 1, wherein the heat deflection temperature (HDT) of the filler is less than the heat deflection temperature of either the first adhesive film or the second adhesive film.

3. The adhesive layer structure as described in claim 1 or 2, wherein the filler is a polymer with a heat distortion temperature between 60 degrees Celsius and 140 degrees Celsius.

4. The adhesive layer structure as described in claim 1, wherein the cross-sectional shape of each of the buffer structures is semi-circular, semi-elliptical, trapezoidal, rectangular, semi-circular shell with a central hollow, or semi-elliptical shell with a central hollow.

5. The adhesive layer structure as described in claim 1, wherein the buffer structures include a plurality of first buffer structures and a plurality of second buffer structures, the first buffer structures and the second buffer structures being staggered.

6. A method for manufacturing a flexible panel, comprising the following steps: disposing a first flexible substrate on a first carrier plate via the adhesive layer structure described in claim 1; forming a first element layer on the first flexible substrate; and separating the first flexible substrate from the first carrier plate.

7. The manufacturing method as described in claim 6 further comprises the following steps: disposing a second flexible substrate on a second carrier plate via the adhesive layer structure described in claim 1; forming a second element layer on the second flexible substrate; assembling the first carrier plate and the second carrier plate opposite to each other to assemble the first flexible substrate and the second flexible substrate, wherein the first element layer and the second element layer are located between the first flexible substrate and the second flexible substrate; and separating the second flexible substrate from the second carrier plate.

8. The manufacturing method as described in claim 6, wherein the step of forming the first element layer includes a process at a temperature greater than or equal to 60 degrees Celsius.

9. The manufacturing method as described in claim 6 further includes forming a cladding layer on the first flexible substrate, wherein the step of forming the cladding layer is prior to the step of forming the first element layer, and the step of forming the cladding layer includes a process at a temperature greater than or equal to 60 degrees Celsius.

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