Foldable laminated and foldable display devices and their manufacturing methods

Abstract

This disclosure relates to foldable stacks and foldable display devices and methods of manufacturing the same. The foldable stack in the embodiments includes: a substrate; a patterned layer disposed along an edge portion of the substrate and including one or more protrusions; and an adhesive layer disposed on the substrate and covering at least a portion of the patterned layer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2021-0070007, filed on May 31, 2021, which is incorporated herein by reference as if fully set forth herein. Technical Field

[0003] This disclosure relates to foldable laminates and foldable display devices and methods of manufacturing the same, and in particular, to foldable laminates and foldable display devices and methods of manufacturing the same that ensure reduced defects in the adhesive layer. Background Technology

[0004] Display devices can be implemented as various devices such as televisions, monitors, smartphones, tablets, laptops, wearable devices, etc.

[0005] In recent years, in order to improve portability, various types of flexible display devices have been developed, such as foldable display devices, rollable display devices, and stretchable display devices.

[0006] A flexible display device refers to a display device that, while possessing the display characteristics of an existing flat panel display device, has a flexible display panel that can be folded, rolled up, bent, or curved.

[0007] In flexible display devices, foldable display devices can be folded to occupy a small space for easy carrying, and can be unfolded to provide a large display screen when in use.

[0008] Foldable display devices are folded and unfolded countless times.

[0009] Folding and unfolding actions can increase folding stress, which can lead to damage to foldable display devices.

[0010] In foldable display devices, reducing folding stress is very important. Summary of the Invention

[0011] In foldable display devices, layers that provide various functions can be stacked, such as cover windows, decorative layers, polarizing layers, display panels, etc.

[0012] An adhesive layer is placed between the layers, and the layers are fixed to each other by the adhesive layer.

[0013] In the folded state, the radius of curvature of the folded section needs to be reduced to decrease the thickness of the foldable display device.

[0014] A decrease in the radius of curvature of the fold leads to an increase in folding stress.

[0015] One way to reduce folding stress is to increase the thickness of the adhesive layer in foldable display devices.

[0016] As the thickness of the adhesive layer increases, the surface area of ​​the adhesive layer's exposed external side surfaces increases.

[0017] As the exposed surface area of ​​the adhesive layer increases, the side surfaces of the adhesive layer can easily become contaminated by processing equipment such as robotic arms, causing the adhesive material to detach or escape from the side surfaces of the adhesive layer. These phenomena are known as adhesive detachment or adhesive escape.

[0018] In addition, when the modulus of the adhesive material decreases and its fluidity increases under high temperature and high humidity, the adhesive material may detach or escape.

[0019] Detachment or escape of adhesive material may lead to an increase in the defect rate and a deterioration in the reliability of foldable display devices.

[0020] The applicant of this disclosure conducted experiments to reduce folding stress and defects in the adhesive layer. In the experiments, they designed a new foldable laminate and a new foldable display device, as well as a new manufacturing method thereof, which can reduce folding stress and defects in the adhesive layer.

[0021] Therefore, embodiments of this disclosure are intended to provide a foldable stacked and foldable display device and a method for manufacturing the same, which substantially avoids one or more problems caused by the limitations and disadvantages of the prior art.

[0022] One aspect of this disclosure is to provide a foldable laminate and a foldable display device and a method for manufacturing the same, which can reduce defects in the adhesive layer caused by the detachment or escape of the adhesive material in the adhesive layer.

[0023] One aspect of this disclosure is to provide a foldable laminate and foldable display device and a method for manufacturing the same, which can effectively control the flow of adhesive material in the adhesive layer.

[0024] One aspect of this disclosure is to provide a foldable stacked and foldable display device and a method for manufacturing the same, wherein multiple layers can be easily arranged and stacked.

[0025] One aspect of this disclosure is to provide a foldable stack and a foldable display device and a method for manufacturing the same, which can reduce the occurrence of defects (or unevenness) caused by a patterned layer disposed along the edge portion of a substrate.

[0026] One aspect of this disclosure is to provide a foldable laminate and a foldable display device and a method for manufacturing the same, which can effectively ensure an appropriate optical density of a patterned layer disposed along the edge portion of a substrate.

[0027] One aspect of this disclosure is to provide a foldable laminate and a foldable display device and a method for manufacturing the same, which allows for easy adjustment of the position of the boundaries of adhesive layers with different moduli.

[0028] Additional features and aspects will be set forth in the following description and will be apparent in part from the description, or may be learned by practicing the inventive concept provided herein. Other features and aspects of the inventive concept may be realized and obtained by means of structures particularly pointed out in the written description or that can be deduced therefrom, as well as by the claims and the accompanying drawings.

[0029] To achieve these and other aspects of the inventive concept, as embodied and broadly described herein, a foldable stack and foldable display device includes: a substrate; a patterned layer disposed along an edge portion of the substrate and including one or more protrusions; and an adhesive layer disposed on the substrate and covering at least a portion of the patterned layer.

[0030] In another aspect, the foldable stack and foldable display device includes: a first substrate; a first pattern layer disposed along an edge portion of the first substrate and including one or more first protrusions; an adhesive layer covering at least a portion of the first substrate and the first pattern layer; a second substrate disposed on the adhesive layer; and a second pattern layer disposed between the adhesive layer and the second substrate, disposed along an edge portion of the second substrate and including one or more second protrusions.

[0031] On the other hand, the foldable stack includes: a substrate; a patterned layer disposed along an edge portion of the substrate and including a body portion, a plurality of protrusions disposed on the body portion and a groove portion disposed between the plurality of protrusions; and an adhesive layer disposed on the substrate, wherein the ends of the adhesive layer overlap with the groove portions.

[0032] In another aspect, the foldable display device includes: a foldable stack; and a display panel disposed on one surface of the foldable stack, wherein the foldable stack includes: a substrate; a pattern layer disposed along an edge portion of the substrate and including one or more protrusions; and an adhesive layer disposed on the substrate and covering at least a portion of the pattern layer.

[0033] In another aspect, a method for manufacturing a foldable laminate includes: first printing a plurality of lower patterned layers spaced apart from each other along an edge portion of a substrate; secondly printing an upper patterned layer to cover the plurality of lower patterned layers; and forming an adhesive layer to cover the substrate and at least a portion of the upper and lower patterned layers.

[0034] In embodiments of this disclosure, the protrusions of the patterned layer formed along the edge portion of the substrate can help reduce the surface area of ​​the adhesive layer exposed to the outside, thereby reducing defects in the adhesive layer caused by the detachment or escape of the adhesive material.

[0035] In embodiments of this disclosure, the protrusions of the patterned layer formed along the edge portion of the substrate can impede the flow of the adhesive material in the adhesive layer, thereby effectively controlling the flow of the adhesive material.

[0036] In embodiments of this disclosure, a first pattern layer and a second pattern layer having an adhesive layer disposed between the edge portions of a first substrate and a second substrate, respectively, can be used as cohesive and alignment marks, thereby facilitating the arrangement and stacking of multiple layers.

[0037] In embodiments of this disclosure, the first protrusion of the first pattern layer and the second protrusion of the second pattern layer can be configured not to overlap each other, thereby preventing excessive increase in the thickness of a specific area of ​​the pattern layer and reducing the occurrence of defects (e.g., unevenness) caused by the pattern layer.

[0038] In embodiments of this disclosure, a two-tone printing method is used to form a pattern layer, in which a lower pattern layer is printed first, followed by an upper pattern layer, thereby easily forming a pattern layer with a predetermined thickness or greater, and effectively ensuring the appropriate optical density of the pattern layer.

[0039] In embodiments of this disclosure, during the step of first printing multiple lower pattern layers in a manner where the lower pattern layers are spaced apart from each other, the position of the space between the lower pattern layers can be adjusted, thereby easily adjusting the position of the boundaries of adhesive layers with different moduli.

[0040] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory, and are intended to provide further illustration of the claimed inventive concept. Attached Figure Description

[0041] The accompanying drawings, included to provide a further understanding of this disclosure and incorporated into and constituting a part of this application, illustrate embodiments of this disclosure and, together with the description, serve to explain various principles. In the drawings:

[0042] Figure 1This is a cross-sectional view illustrating one embodiment of a foldable display device;

[0043] Figure 2a and Figure 2b These are diagrams showing the detachment and escape of adhesive material before and after the thickness of the adhesive layer in the foldable laminate increases;

[0044] Figure 3 This is a cross-sectional view illustrating one embodiment of a foldable stack;

[0045] Figures 4a to 4c This is a process diagram of a manufacturing method for a foldable stacked structure, one embodiment of which is shown.

[0046] Figures 5a to 5c This is a process diagram of a manufacturing method for a foldable and stackable structure according to another embodiment;

[0047] Figures 6a to 6c This is a process diagram of a manufacturing method for a foldable and stackable structure according to another embodiment;

[0048] Figures 7a to 7c This is a cross-sectional view showing the patterned layer and adhesive layer in various embodiments;

[0049] Figures 8a to 8c This is a cross-sectional view and a plan view illustrating another embodiment of the foldable stack;

[0050] Figures 9a to 9c This is a cross-sectional view and a plan view illustrating another embodiment of the foldable stack;

[0051] Figures 10a to 10c This is a cross-sectional view and a plan view illustrating another embodiment of the foldable stack; and

[0052] Figures 11a to 11d This is a cross-sectional view and a plan view illustrating another embodiment of the foldable stack. Detailed Implementation

[0053] The advantages and features of this disclosure, as well as methods of implementing it, can be clearly understood from the embodiments described with reference to the accompanying drawings. However, the subject matter of this disclosure can be embodied in various different forms and should not be construed as limited to the embodiments set forth herein. Rather, embodiments are provided as examples so that this disclosure may be thorough and complete, and its scope will be fully conveyed to those skilled in the art. The subject matter of this disclosure should be limited only by the scope of the appended claims.

[0054] The shapes, dimensions, ratios, angles, quantities, etc., of the components shown in the accompanying drawings provided to describe embodiments of this disclosure are given by way of example only, and the subject matter of this disclosure is not limited to the details in the drawings. Throughout the disclosure, similar reference numerals denote similar components. In describing this subject matter, detailed descriptions of well-known technologies related to this disclosure are omitted if they are deemed to unnecessarily obscure the essential points of this disclosure. Throughout the disclosure, the terms “comprising,” “having,” “consisting of,” etc., will mean including any other components, unless these terms are used in conjunction with the term “only.” Furthermore, unless explicitly stated otherwise, the singular forms “a,” “an,” and “the” are also intended to include the plural forms.

[0055] When describing a component, the error margin should be included even if it is not explicitly described.

[0056] In this disclosure, when spatial terms such as “on top of,” “on the upper part,” “on the lower part,” “adjacent” are used to describe the positional relationship between two components, one or more additional components may be placed between the two components unless terms such as “exactly” or “directly” are used.

[0057] When using time terms such as “after,” “next,” “following,” “before,” etc. to describe time sequence, one or more additional events may be placed between the two events unless terms such as “exactly” or “directly” are used.

[0058] When describing components, terms such as first, second, etc., may be used. These terms are intended only to distinguish one component from another, and the components are not limited by these terms. Therefore, within the technical spirit of this disclosure, the first component described below may be the second component.

[0059] The features of the embodiments of this disclosure can be combined or mixed in part or in whole, and can be interlocked and operated in various technical ways. Furthermore, each embodiment can be implemented independently or in relation to each other.

[0060] The following describes in detail a foldable laminate and a foldable display device that reduces folding stress and defects in the adhesive layer, and a method for manufacturing the same.

[0061] Figure 1 This is a cross-sectional view showing one embodiment of a foldable display device.

[0062] like Figure 1 As shown, the foldable display device 1 may include a support layer 10, a display panel 20, a touch panel 30, a polarizing layer 40, a protective layer 50, a cover window 70, and a coating 80.

[0063] The adhesive layer 90 can be disposed between the layers and connect, attach or fix each layer.

[0064] The order of the layers constituting the foldable display device 1 is not limited to Figure 1 The order of the layers can be changed, and the order in which the layers are stacked can be altered.

[0065] The layers constituting the foldable display device 1 are not limited to Figure 1 The layers shown. Layers with various functions can be added, and some layers can be omitted when necessary.

[0066] The support layer 10 can be disposed on the rear surface of the display panel 20 and protect the display panel 20 from external moisture, external heat, external impact, etc.

[0067] The support layer 10 may be a back plate that supports the rear surface of the display panel 20. The support layer 10 may include, but is not limited to, a polyethylene terephthalate (PET) film or a metal film.

[0068] The frame can be additionally installed on the rear surface of the support layer 10 and protect the support layer 10, display panel 20, etc.

[0069] The frame can be formed in such a way that it is removed in some areas where the foldable display device 1 is folded, rather than being formed to correspond to the entire surface of the support layer 10.

[0070] For example, the foldable display device 1 may include a folded area that is folded and an open area that is not folded. The frame may be located in the open area instead of the folded area.

[0071] For example, multiple frames can be placed in non-folded areas instead of folded areas to reduce the folding stress applied to the frames, thereby minimizing damage to the frames.

[0072] The display panel 20 can be mounted on the support layer 10.

[0073] The display panel 20 can generate the image to be displayed. The type of display panel 20 is not limited, but includes organic light-emitting display panels or micro light-emitting diode display panels, which are advantageous in embodying flexible display devices.

[0074] The display panel 20 may include a pixel array having multiple pixels.

[0075] The area corresponding to the pixel array can be the display area, and the remaining area outside the display area can be a non-display area that serves as a border area.

[0076] A pixel array can be set in a pixel region defined by a signal line and includes multiple pixels that display an image based on a signal provided to the signal line.

[0077] Signal lines can include gate lines, data lines, pixel drive power lines, etc.

[0078] Each of the plurality of pixels may include: a switching thin-film transistor in the pixel region, an anode electrode electrically connected to the switching thin-film transistor, a light-emitting element layer formed on the anode electrode, and a cathode electrode electrically connected to the light-emitting element layer.

[0079] For example, the light-emitting element layer may include organic light-emitting elements formed on the anode electrode.

[0080] For example, organic light-emitting elements can be implemented in a way that each pixel emits the same color of light, such as white light, or in a way that each pixel emits different colors of light, such as red light, green light, or blue light.

[0081] In another example, the light-emitting element layer may include miniature light-emitting diode elements electrically connected to the anode electrode and the cathode electrode, respectively.

[0082] The miniature light-emitting diode element can be a light-emitting diode implemented in the form of an integrated circuit (IC) or a chip, and includes a first terminal electrically connected to the anode electrode and a second terminal electrically connected to the cathode electrode.

[0083] The touch panel 30 can be mounted on the display panel 20.

[0084] The touch panel 30 can sense user touch input such as screen touch or touch coordinates, and sense input signals based on user touch or tool touch through the overlay window 70.

[0085] The touch panel 30 can be implemented using various methods based on thin-layer resistance, capacitance, optics, or electromagnetism, without limitation.

[0086] The touch panel 30 may include multiple touch electrodes and a touch sensor structure, the touch sensor structure including multiple touch wirings for connecting the touch electrodes to a touch sensing circuit.

[0087] The polarization layer 40 can be disposed on the touch panel 30.

[0088] The display panel 20 may include various metal materials for thin-film transistors, signal lines, electrodes, light-emitting elements, etc.

[0089] External light incident on the display panel 20 can be reflected by the metal material, and the reflection of external light may worsen the visibility of the foldable display device 1.

[0090] Because the polarization layer 40, including the retardation film, selectively transmits light, the reflection of external light incident on the display panel 20 can be reduced. Therefore, the outdoor visibility of the foldable display device 1 can be improved.

[0091] The protective layer 50 can be formed on the polarization layer 40.

[0092] Even when the display panel 20 is not displaying an image, the protective layer 50 can be a layer with a pattern visible to the user. The protective layer 50 can be a decorative layer and is not limited to this terminology.

[0093] The pattern layer 60 can be set along the edge portion of the protective layer 50.

[0094] For example, pattern layer 60 can be disposed on protective layer 50 to correspond to the border area of ​​display panel 20.

[0095] For example, the decorative film or protective film may include a protective layer 50 and a pattern layer 60. Additionally, a release layer serving as a surface protective film may be formed on the front and rear surfaces of the decorative film or protective film, and the release layer may protect the outer surface of the decorative film or protective film.

[0096] When a decorative film or protective film is formed on the polarizing layer 40, the protective layer 50 and the pattern layer 60 left after the separation layer are stacked on the polarizing layer 40. Accordingly, the protective layer 50 can support the pattern layer 60 and prevent damage to the pattern layer 60 during the separation of the separation layer.

[0097] Pattern layer 60 can be a decorative layer on which decorations are basically printed.

[0098] The pattern layer 60 may include various materials such as organic and inorganic materials. The materials of the pattern layer 60 are not limited.

[0099] For example, organic materials can include black ink or carbon black. Inorganic materials can include, for example, silicon oxide (SiO2) films, silicon nitride (SiN) films, etc. x Materials such as membranes and metals.

[0100] When the pattern layer 60 is made of organic materials, photoresist treatment, screen printing, coating, etc. can be used. When the pattern layer 60 is made of inorganic materials, deposition treatment, etc. can be used.

[0101] For example, pattern layer 60 can be formed as a color layer with black.

[0102] In this case, even if the display panel 20 does not display an image, the border area of ​​the display panel 20 can be displayed in essentially the same color as the display area of ​​the display panel 20, thereby making the screen of the display panel 20 appear wider.

[0103] For example, pattern layer 60 can be formed as a black matrix.

[0104] Black matrix can be applied as a resin-based organic film. For example, coloring organic resins, including any of carbon black or black pigments (such as acrylic resins, epoxy resins, or polyimide resins), can be applied to the black matrix.

[0105] Covering window 70 can be formed on protective layer 50 and pattern layer 60.

[0106] The cover window 70 can protect the protective layer 50, polarizing layer 40, touch panel 30, display panel 20 and other components underneath from external impacts, moisture, heat and other effects.

[0107] Therefore, glass or plastic film with impact resistance and light transmittance can be used to cover windows 70.

[0108] When the cover window 70 is made of glass, a protective film including polyethylene terephthalate (PET) can be additionally formed on one surface of the cover window 70 to prevent the cover window 70 from breaking into small pieces due to external force or stress.

[0109] When the covering window 70 is formed as a plastic film, acrylic film, colorless polyimide film, etc. can be used.

[0110] The coating 80 can be formed on the cover window 70 and protect the cover window 70 from external impacts.

[0111] The coating 80 may comprise a colorless organic-inorganic mixture. Therefore, the coating 80 can effectively protect the cover window 70 and reduce the degradation of light transmittance.

[0112] The adhesive layer 90 may be formed between the support layer 10, display panel 20, touch panel 30, polarizing layer 40, protective layer 50, cover window 70 and coating 80 described above, to bond (or connect) or fix the layers.

[0113] The adhesive layer 90 can be made of a material with high adhesion and high transparency.

[0114] The adhesive layer 90 in this disclosure may represent a layer that ensures viscosity and adhesion.

[0115] The adhesive layer 90 can have suitable adhesion so that no bubbles or separation will occur even when the adhesive layer 90 formed between the layers is bent, and the adhesive layer 90 has viscoelasticity so that the adhesive layer 90 can be used in the foldable display device 1.

[0116] The adhesive layer 90 may comprise an acrylic-based composition or a silicone-based composition. For example, the adhesive layer 90 may comprise an optically clear adhesive (OCA) composition or a pressure-sensitive adhesive (PSA) composition.

[0117] The foldable display device 1 may include a foldable area and a non-foldable area.

[0118] In its folded state, the foldable display device 1 has a large thickness. To reduce the thickness of the foldable display device 1 in its folded state, the radius of curvature of the fold in the folding region can be reduced.

[0119] The reduction in the folding radius of curvature leads to a reduction in the thickness of the foldable display device 1 in the folded state, while also increasing the folding stress.

[0120] To reduce folding stress, the thickness of the adhesive layer 90 of the foldable display device 1 can be increased.

[0121] Figure 2a and Figure 2b The foldable stack 2 constituting the foldable display device is shown before and after the thickness of the adhesive layer of the foldable stack is increased.

[0122] like Figure 2a As shown, in the foldable stack 2, multiple substrates 100 can be stacked, and each substrate 100 can be fixed by an adhesive layer 200.

[0123] In this configuration, the substrate 100 is disposed on the upper and lower surfaces of the adhesive layer 200, such that the upper and lower surfaces of the adhesive layer 200 are not exposed to the outside. However, the side surfaces of the adhesive layer 200 are exposed to the outside.

[0124] When the thickness of the adhesive layer 200 is increased to reduce folding stress, such as Figure 2b As shown, the surface area of ​​the adhesive layer 200 exposed to the outside is significantly increased.

[0125] As the surface area of ​​the adhesive layer 200 exposed to the outside increases, the side surface of the adhesive layer 200 may be easily contaminated by processing equipment such as robotic arms used in the processing.

[0126] Therefore, the adhesive material can detach (A) or escape (B) from the side surface of the adhesive layer 200, such as Figure 2b As shown.

[0127] In addition, under high temperature and high humidity, the adhesive material of the adhesive layer 200 has low modulus and high fluidity, which causes the adhesive material to detach (A) or escape (B) more frequently due to the increased thickness of the adhesive layer 200.

[0128] When the adhesive material detaches (A) or escapes (B), the adhesive layer 200 may not function properly, or the adhesive material may contaminate other components in the foldable display device 1, leading to an increase in the defect rate and a deterioration in the reliability of the foldable display device 1.

[0129] In this disclosure, various embodiments of the foldable laminate 2, the foldable display device 1, and the manufacturing method thereof that help reduce folding stress and defects in the adhesive layer 200 are described below.

[0130] Figure 3 This is a cross-sectional view showing one embodiment of the foldable stack 2.

[0131] The foldable stack 2 may include a substrate 100.

[0132] In this disclosure, substrate 100 may include layers such as a support layer, a polarizing layer, a protective layer, a cover window, and a coating, which are included in the foldable display device 1 and perform various functions. If the foldable display device 1 has additional functional layers, those functional layers may be included in substrate 100.

[0133] The first adhesive layer 210 and the second adhesive layer 220 can be disposed on one surface and the other surface of the substrate 100, respectively. That is, the adhesive layer 200 can be disposed on the upper surface and the lower surface of the substrate 100, respectively.

[0134] A protective film can be applied to one surface of each adhesive layer 200.

[0135] Therefore, the first protective film 211 can be disposed on the first adhesive layer 210, and the second protective film 221 can be disposed below the second adhesive layer 220.

[0136] When the foldable stack 2 is stored or moved, the protective film can prevent the substrate 100 and the adhesive layer 200 from being contaminated or damaged.

[0137] The protective film can be a release film. The foldable stack 2 is moved to another foldable stack 2, the protective film is removed, and then the exposed adhesive layer 200 contacts the other foldable stack 2 to stably stack and fix the foldable stack 2.

[0138] In other words, at least one of the protective films can be removed before the foldable stack 2 is stacked on top of another foldable stack 2.

[0139] The pattern layer 300 can be formed along the edge portion of the substrate 100.

[0140] The pattern layer 300 can be disposed on one surface of the substrate 100 and is disposed between the adhesive layer 200 and the substrate 100.

[0141] exist Figure 3 In this configuration, the pattern layer 300 is disposed between the first adhesive layer 210 and the substrate 100, but is not limited thereto. For example, the pattern layer 300 may be disposed between the second adhesive layer 220 and the substrate 100.

[0142] For ease of description, Figure 3 In this context, adhesive layer 200 refers to the first adhesive layer 210.

[0143] The pattern layer 300 may be disposed on the substrate 100, and the adhesive layer 200 may be disposed to cover at least a portion of the pattern layer 300.

[0144] Therefore, the adhesive layer 200 can be configured to directly contact the substrate 100 and the pattern layer 300.

[0145] The adhesive layer 200 may cover the entire area of ​​the pattern layer 300, but is not limited thereto. For example, the adhesive layer 200 may be configured not to cover an area of ​​the pattern layer 300 that extends inward from the end of the foldable stack 2 by a predetermined distance.

[0146] When removing the edge portion of the foldable stack 2 in a subsequent process such as trimming, the area inserted inward from the end of the foldable stack 2 at a predetermined distance can be the edge area that is removed and disappears.

[0147] The pattern layer 300 may include one or more protrusions 321, and the protrusions 321 of the pattern layer 300 may be provided along the edge portion on the substrate 100.

[0148] One or more protrusions 321 can be formed in the pattern layer 300, and when multiple protrusions 321 are provided, each of the protrusions 321 can be separated by a predetermined interval.

[0149] Since the pattern layer 300 formed along the edge portion on the substrate 100 includes one or more protrusions 321 as described above, the surface area of ​​the exposed side surface of the adhesive layer 200 can be further reduced.

[0150] Therefore, defects in the adhesive layer 200 caused by the adhesive material detaching or escaping from the side surface of the adhesive layer 200 can be reduced.

[0151] Additionally, the protrusions 321 of the patterned layer 300 formed along the edge portion of the substrate 100 can serve as a dam to impede the flow of adhesive material in the adhesive layer 200.

[0152] Therefore, the foldable laminate is exposed to environments with high temperature and high humidity, and the modulus of the adhesive material becomes lower. Although the flowability of the adhesive material increases, the protrusions 321 of the patterned layer 300 can effectively control the flow of the adhesive material.

[0153] Therefore, controlling the flow of adhesive materials can reduce the occurrence of adhesive material detachment or escape.

[0154] In the following text, refer to Figures 4a to 4c , Figures 5a to 5c and Figures 6a to 6c The manufacturing method of the foldable stack 2 is described, focusing mainly on the method of forming the patterned layer 300.

[0155] Figures 4a to 4c , Figures 5a to 5c and Figures 6a to 6c These are process diagrams illustrating the manufacturing methods of the patterned layer in various implementation embodiments.

[0156] Reference Figure 4a The patterned layer 300 formed on the substrate 100 includes a plurality of protrusions 321, each protrusion 321 including a first protrusion 321a and a second protrusion 321b, and the first protrusion 321a and the second protrusion 321b may have substantially the same width. For example, the first protrusion 321a may be a protrusion, and is not limited to this terminology. For example, the second protrusion 321b may be a protrusion, and is not limited to this terminology.

[0157] The first protrusion 321a and the second protrusion 321b are formed along the edge portion of the substrate 100 and are spaced apart from each other. Accordingly, a groove 330 may be formed between the first protrusion 321a and the second protrusion 321b.

[0158] The groove portion 330 of the pattern layer 300 can be formed along the edge portion of the substrate 100.

[0159] Figure 4b and Figure 4c The process for forming the groove portion 330 of the pattern layer 300 is shown.

[0160] Reference Figure 4b Multiple lower pattern layers 310 are first printed along the edge portion of the substrate 100 in such a manner that the lower pattern layers 310 are spaced apart from each other.

[0161] Multiple lower pattern layers 310 can have substantially the same width.

[0162] Then, the upper pattern layer 320 is printed in the following manner: the upper pattern layer 320 covers multiple lower pattern layers 310.

[0163] In this case, the same material can be used for both the lower and upper patterning layers.

[0164] When the upper pattern layer 320 is stacked on the lower pattern layer 310, a foldable stacked pattern layer 300 can be formed.

[0165] Since a space is formed between multiple lower pattern layers 310 in the first printing step, after the second printing step of printing the upper pattern layer 320, the pattern layer 300 can be formed to include multiple protrusions 321, and the multiple protrusions 321 can be spaced apart along the substrate 100.

[0166] Therefore, since the groove portion 330 is formed between the plurality of protrusions 321, the pattern layer 300 can be formed to include the groove portion 330 and the plurality of protrusions 321.

[0167] As described above, the manufacturing method of the foldable stack 2 in the embodiment may include first printing a lower pattern layer 310 and then printing an upper pattern layer 320 to form a pattern layer 300. For example, the manufacturing method of the foldable stack 2 may be a two-tone printing method, wherein the lower pattern layer 310 is printed first, and then the upper pattern layer 320 is printed.

[0168] It is necessary to ensure a predetermined value or greater optical density so that the pattern layer 300 has effective optical properties.

[0169] Optical density is related to the thickness of pattern layer 300. To ensure a predetermined or greater optical density, the thickness of pattern layer 300 needs to be increased.

[0170] It is difficult to form a pattern layer 300 with a predetermined thickness or greater in a single printing process.

[0171] When the pattern layer 300 is formed using the two-tone printing method as described in the embodiments, the pattern layer 300 may have a predetermined thickness or greater, thereby ensuring the appropriate optical density of the pattern layer 300.

[0172] Furthermore, because the multiple lower pattern layers 310 are formed in a manner that separates them from each other during the first printing step, the groove portion 330 can be easily formed together with the multiple protrusions 321 after the second printing step. Therefore, the thickness of the pattern layer 300 can be increased and it can have a predetermined value or a greater optical density.

[0173] Figures 4a to 4c It is shown that the first protrusion 321a and the second protrusion 321b have substantially the same width. However, as Figures 5a to 5c and Figures 6a to 6c As shown, the first protrusion 321a and the second protrusion 321b can have different widths.

[0174] Reference Figure 5a The pattern layer 300 formed on the substrate 100 includes a plurality of protrusions 321, each protrusion 321 including a first protrusion 321a and a second protrusion 321b, wherein the width of the first protrusion 321a is greater than the width of the second protrusion 321b.

[0175] Therefore, in Figure 5a The groove portion 330 formed between the first protrusion 321a and the second protrusion 321b can be more than Figure 4a The groove portion is moved to the inner side of the substrate 100.

[0176] In order to move the groove portion 330 of the pattern layer 300 further to the inside of the substrate 100, when... Figure 5b As shown, when printing the pattern layer 310 first, the width of the first protrusion 321a needs to be greater than the width of the second protrusion 321b.

[0177] Since the first protrusion 321a and the second protrusion 321b are printed in a manner that the first protrusion 321a and the second protrusion 321b are spaced apart from each other, therefore Figure 5b The space between the first protrusion 321a and the second protrusion 321b can be greater than Figure 4b The space within is moved to the inside of the substrate 100.

[0178] Reference Figure 5c When the upper pattern layer 320 is printed a second time on the lower pattern layer 310, the groove portion 330 is formed in a position corresponding to the space between the first protrusion 321a and the second protrusion 321b. Therefore, Figure 5c The groove portion 330 in the middle can be compared to Figure 4a The groove portion is moved to the inner side of the substrate 100.

[0179] Reference Figure 6a The pattern layer 300 formed on the substrate 100 includes a plurality of protrusions 321, each protrusion 321 including a first protrusion 321a and a second protrusion 321b, wherein the width of the first protrusion 321a is smaller than the width of the second protrusion 321b.

[0180] Therefore, in Figure 6a The groove portion 330 formed between the first protrusion 321a and the second protrusion 321b can be more than Figure 4a The groove portion in the middle is moved to the outside of the substrate 100.

[0181] In order to move the groove portion 330 of the pattern layer 300 to the outside of the substrate 100, when... Figure 6b As shown, when printing the pattern layer 310 first, the width of the first protrusion 321a can be smaller than the width of the second protrusion 321b.

[0182] Since the first protrusion 321a and the second protrusion 321b are spaced apart from each other, Figure 6b The space between the first protrusion 321a and the second protrusion 321b can be greater than Figure 4b The space within is moved to the outside of the substrate 100.

[0183] Reference Figure 6c When the upper pattern layer 320 is printed a second time on the lower pattern layer 310, the groove portion 330 is formed in a position corresponding to the space between the first protrusion 321a and the second protrusion 321b. Therefore, Figure 6c The groove portion 330 in the middle can be compared to Figure 4a The groove portion in the middle is moved to the outside of the substrate 100.

[0184] In the embodiment, as described above, in the step of first printing multiple lower pattern layers 310 spaced apart from each other, the width of the lower pattern layers 310 is adjusted to adjust the position of the space between the lower pattern layers 310. Therefore, the position in which the groove portion 330 of the pattern layer 300 is formed can be easily adjusted.

[0185] During the manufacturing process of the foldable laminate 2, the boundary of the adhesive layer 200, which is formed to cover the pattern layer 300, can be in the groove portion 330. Adjusting the position of the groove portion 330 can mean adjusting the position of the boundary of the adhesive layer 200.

[0186] When the position of the groove portion 330 of the pattern layer 300 is adjusted, the position of the boundary of the adhesive layer 200 with different moduli can be easily adjusted.

[0187] In the following text, refer to Figures 7a to 7c Various embodiments of the groove portion 330 in this disclosure are described in detail.

[0188] The pattern layer 300 may include one or more of a body portion 311 and protrusions 321 disposed on the body portion 311.

[0189] At least one protrusion 321 may be spaced inwardly from the end of the body portion 311 by a predetermined distance.

[0190] When the pattern layer 300 includes a plurality of protrusions 321, the protrusions 321 can be spaced apart from each other by a predetermined distance.

[0191] Therefore, the groove portion recessed toward the body portion 311 can be formed in the space between the protrusions 321 that are spaced apart from each other.

[0192] As described above, the pattern layer 300 formed based on two-tone printing includes: a body portion 311, a plurality of protrusions 321 disposed on the body portion 311, and groove portions 330 disposed between the protrusions 321.

[0193] One or more of the protrusions 321 may be configured to be more inward than the end of the body portion 311.

[0194] For example, the surface area of ​​the lower pattern layer 310 formed in the first printing step can be larger than the surface area of ​​the upper pattern layer 320 formed in the second printing step, such that all the plurality of protrusions 321 of the pattern layer 300 formed after the two-tone printing process are set to be more inward than the end of the body portion 311.

[0195] Therefore, as Figures 7a to 7c As shown, the plurality of protrusions 321 can be configured to be positioned further inward by a predetermined distance than the end of the body portion 311, so as to have a first edge region 311a and a second edge region 311b.

[0196] After a foldable stack 2 is stacked on top of another foldable stack 2, a portion of the end of the foldable stack 2 can be removed during a finishing process if necessary. In an additional process, a second edge region 311b that extends further outward than the first edge region 311a can be removed. For example, the finishing process can include laser cutting, but is not limited to this.

[0197] Therefore, the end of one of the multiple protrusions 321 can be aligned with the end of the body portion 311. The end of another protrusion 321, including the first edge region 311a, can be set to be further inward than the end of the body portion 311.

[0198] In the foldable stack 2 of the embodiment, at least one end of the protrusion 321 is configured to be further inward than the end of the body portion 311. Therefore, the protrusion 321 and the body portion 311 can be formed as steps.

[0199] When the pattern layer 300 is formed with the protrusion 321 and the body 311 having a stepped shape, the folding stress applied to the pattern layer 300 can be reduced.

[0200] When the ends of the protrusion 321 and the body portion 311 are aligned, the increase in the width and thickness of the pattern layer 300 may lead to an increase in the folding stress concentrated on the pattern layer 300 when the foldable stack 2 is folded.

[0201] For the patterned layer 300 of the foldable stack 2 in the embodiment, the body portion 311 partially has an edge region. Therefore, the patterned layer 300 has a local region with reduced width and thickness, thereby significantly reducing the folding stress applied to the patterned layer 300 when the foldable stack 2 is folded.

[0202] The groove portion 330 of the pattern layer 300 can be formed into various cross-sectional shapes, and its shape is not limited. For example, the groove portion 330 can have, for example, Figure 7a The inverted triangle in the middle Figure 7b inverted trapezoid and Figure 7c The semi-circular cross-section in the middle.

[0203] Reference Figure 7a When the groove portion 330 has an inverted triangular cross-section, the groove portion 330 can be realized by a printing method based on the step of using the lower pattern layer 310.

[0204] To achieve the groove 330, screen printing can be applied in one example, while photolithography can be applied in another.

[0205] Reference Figure 7b When the trench portion 330 has an inverted trapezoidal cross-section, photolithography can be used to realize the trench portion 330.

[0206] For example, a photoresist film applied using a mask pattern with a predetermined pattern is exposed and developed to achieve an inverted trapezoidal cross-section.

[0207] Reference Figure 7c When the trench portion 330 has a semi-circular cross-section, photolithography can be used to realize the trench portion 330.

[0208] For example, a photoresist film applied using a halftone mask pattern is exposed and developed to achieve a semi-circular cross-section.

[0209] For example, a halftone mask can be formed by inserting a mask pattern with a mesh structure.

[0210] As described above, the pattern layer 300 in the embodiment is formed using a two-tone printing method, in which two printing stages are performed, and then the adhesive layer 200 is formed.

[0211] For example, the adhesive layer 200 is formed to cover the substrate 100 and at least a portion of the pattern layer 300, which includes the lower pattern layer 310 and the upper pattern layer 320.

[0212] In this case, the end of the adhesive layer 200 can be formed and provided such that the end of the adhesive layer 200 overlaps with the groove portion 330.

[0213] If there is no groove 330 at the end of the adhesive layer 200 formed on the pattern layer 300, the end of the adhesive layer 200 formed on the pattern layer 300 will pass through the pattern layer 300 and escape from the foldable stack 2. This phenomenon is called adhesive material escape. To prevent adhesive material escape, a very precise process is required.

[0214] For example, the flow viscosity of the adhesive material varies depending on the modulus of the adhesive layer 200. Therefore, it would be very difficult to accurately determine the location of the boundary of the adhesive layer 200 based on the modulus of the adhesive layer 200 to be used.

[0215] In one embodiment, the edge of the adhesive layer 200 is disposed in a groove 330 of the pattern layer 300, the groove having a recessed groove. Therefore, the position of the edge of the adhesive layer 200 can be adjusted more easily.

[0216] The adhesive layer 200 can be made of materials with different moduli. Depending on the modulus, the cross-section of the groove 330 may vary.

[0217] For example, the adhesive layer 200 includes a 1×10 7 In the case of adhesive materials with a relatively high modulus of Pa or greater, the flow viscosity of the adhesive layer 200 is high, which means that the adhesive material will not spread widely. Therefore, the groove portion 330 may not have a large width.

[0218] When the adhesive layer 200 includes an adhesive material with a high modulus, the pattern layer 300 can have grooves 330 with, for example, Figure 7a It is formed in the way shown by the inverted triangle shape cross-section.

[0219] For example, the adhesive layer 200 includes layers with a diameter of 1×10. 5 Pa to 1×10 7 In the case of a medium modulus adhesive material, the flow viscosity of the adhesive layer 200 is at a medium level, and the adhesive material further diffuses. Therefore, the width of the groove portion 330 in the adhesive layer 200 including a medium modulus adhesive material can be greater than the width of the groove portion 330 in the adhesive layer including a high modulus adhesive material.

[0220] When the adhesive layer 200 comprises an adhesive material with a medium modulus, the pattern layer 300 may have grooves 330 with, for example, Figure 7b The cross-section is formed in the manner shown in the diagram, which is an inverted trapezoidal shape.

[0221] Unlike an inverted triangular cross-section, an inverted trapezoidal cross-section has an additional side of predetermined length. Even if the adhesive material with a medium modulus diffuses to a certain extent, the inverted trapezoidal cross-section can help retain a greater amount of adhesive material in the groove 330 compared to the inverted triangular cross-section.

[0222] For example, the adhesive layer 200 includes layers with a diameter of less than 1×10⁻⁶. 5In the case of a relatively low modulus adhesive material, the flow viscosity of the adhesive layer 200 is low, and the adhesive material diffuses so extensively. Therefore, the width of the groove portion 330 in the adhesive layer 200, which includes an adhesive material with a low modulus, can be greater than the width of the groove portion 330 in the adhesive layer, which includes an adhesive material with a medium modulus.

[0223] When the adhesive layer 200 includes an adhesive material with a low modulus, the pattern layer 300 can have grooves 330 with the following characteristics: Figure 7c It is formed in the way shown by the semi-circular cross-section.

[0224] The semi-circular cross-section has a wider groove than the inverted triangular or inverted trapezoidal cross-section. Even with such extensive diffusion of the low-modulus adhesive material, the semi-circular cross-section can help retain a greater amount of adhesive material in the groove 330 compared to the inverted triangular or inverted trapezoidal cross-section.

[0225] As described above, in this embodiment, the shape of the groove portion 330 of the pattern layer 300 can be changed depending on the adhesive material of the adhesive layer 200 having a different modulus. Therefore, the escape of adhesive material can be easily reduced.

[0226] Another method for adjusting the boundary position of the adhesive layer 200 includes changing the position of the groove portion 330 formed due to the adjustment of the position of the space between the lower pattern layers 310, such as... Figures 4a to 4c , Figures 5a to 5c and Figures 6a to 6c As shown.

[0227] In this embodiment, since the position of the groove portion 330 of the pattern layer 300 can be changed depending on the adhesive material of the adhesive layer 200 with different moduli, the escape of the adhesive material can be easily reduced.

[0228] In the following text, refer to Figures 8a to 8c , Figures 9a to 9c , Figures 10a to 10c as well as Figures 11a to 11d Describe the foldable stack 2 in various other embodiments.

[0229] The foldable stack 2 may include a first substrate 100a and a first pattern layer 300a disposed along the edge portion of the first substrate 100a.

[0230] An adhesive layer 200 covering at least a portion of the first substrate 100a and the first pattern layer 300a is formed on the first substrate 100a.

[0231] The second substrate 100b is formed on the adhesive layer 200, and the second pattern layer 300b is formed between the adhesive layer 200 and the second substrate 100b along the edge portion of the second substrate 100b.

[0232] The first pattern layer 300a includes one or more first protrusions 301a, and the second pattern layer 300b includes one or more second protrusions 301b.

[0233] For example, a first pattern layer 300a is formed on the upper surface of the first substrate 100a, and a second pattern layer 300b is formed on the lower surface of the second substrate 100b. The first pattern layer 300a and the second pattern layer 300b may be formed facing each other, with an adhesive layer 200 therebetween.

[0234] Therefore, the adhesive layer 200 can directly contact the first substrate 100a, the first pattern layer 300a, the second substrate 100b, and the second pattern layer 300b.

[0235] The second pattern layer 300b can be configured to correspond to the first pattern layer 300a. The first protrusion 301a and the second protrusion 301b can be formed along the edge portions of the first substrate 100a and the second substrate 100b.

[0236] In other embodiments, one surface of the adhesive layer 200 disposed between the first substrate 100a and the second substrate 100b contacts the first protrusion 301a of the first pattern layer 300a, and the other surface of the adhesive layer 200 contacts the second protrusion 301b of the second pattern layer 300b. Therefore, as described above, the surface area of ​​the side surface of the adhesive layer 200 exposed to the outside can be further reduced.

[0237] Furthermore, since the protrusions are formed on both one surface and the other surface of the adhesive layer 200, the flow of the adhesive material can be prevented more effectively and more easily, even when using an adhesive material with high fluidity.

[0238] In other embodiments, defects in the adhesive layer 200 caused by the detachment or escape of the adhesive material can be significantly reduced.

[0239] The first pattern layer 300a and the second pattern layer 300b (with an adhesive layer 200 therebetween) disposed in the edge portions of the first substrate 100a and the second substrate 100b respectively can be used as cohesive and alignment marks, and multiple layers can be easily aligned and stacked.

[0240] Alignment markers can be used to accurately align and stack multiple layers in the desired location.

[0241] For example, alignment marks can utilize optical properties such as transmission or reflection. The patterned layer needs to ensure that its optical density is sufficient for its use as alignment marks.

[0242] In this regard, the first pattern layer 300a and the second pattern layer 300b in the embodiment can be easily formed with a predetermined thickness using a two-tone printing method, and the optical density can be effectively ensured to the extent that the first pattern layer 300a and the second pattern layer 300b are used as alignment marks.

[0243] Since pattern layers 300a and 300b are formed on different substrates 100a and 100b respectively, in the embodiment, when each of the substrates 100a and 100b is stacked, the pattern layers 300a and 300b formed on each substrate 100a and 100b can be used as cohesion and alignment marks.

[0244] Furthermore, since each of the pattern layers 300a and 300b includes protrusions 301a and 301b, in this embodiment, when the camera device identifies the boundary surfaces of the pattern layers 300a and 300b, the camera device used for alignment can identify the protruding patterns. Therefore, the camera device can more accurately confirm the boundary surfaces of the alignment marks.

[0245] like Figure 8a , Figure 8b and Figure 8c As shown, the first pattern layer 300a and the second pattern layer 300b can have the same pattern or the same shape.

[0246] Figure 8a This shows that the boundary surface of the end of the adhesive layer 200 is aligned with the boundary surfaces of the ends of the first pattern layer 300a and the second pattern layer 300b, and Figure 8b It is shown that the boundary surface of the end of the adhesive layer 200 is set to be more inward than the boundary surfaces of the ends of the first pattern layer 300a and the second pattern layer 300b.

[0247] The position of the boundary surface at the end of the adhesive layer 200 can vary depending on the modulus of the adhesive material used for the adhesive layer 200.

[0248] In addition, the position of the boundary surface of the end of the adhesive layer 200 may vary depending on whether the end trimming process of the foldable stack 2 is performed.

[0249] Reference Figure 8cThe first pattern layer 300a on the first substrate 100a and the second pattern layer 300b on the second substrate 100b may have the same shape or the same pattern. For example, the first pattern layer 300a on the first substrate 100a and the second pattern layer 300b on the second substrate 100b may be formed symmetrically.

[0250] Reference Figure 8a , Figure 8b and Figure 8c Individual protrusions 301a and 301b are formed on each pattern layer 300a and 300b. However, it is possible to... Figure 9a , Figure 9b and Figure 9c The diagram shows multiple protrusions.

[0251] For example, when each pattern layer is like Figure 9a , Figure 9b and Figure 9c When multiple protrusions are shown, the first pattern layer 300a and the second pattern layer 300b can have the same pattern.

[0252] Figure 9a This shows that the boundary surface of the end of the adhesive layer 200 is aligned with the boundary surfaces of the ends of the first pattern layer 300a and the second pattern layer 300b, and Figure 9b It is shown that the boundary surface of the end of the adhesive layer 200 is set to be more inward than the boundary surfaces of the ends of the first pattern layer 300a and the second pattern layer 300b.

[0253] One or more grooves 302a and 302b may be formed between the multiple protrusions 301a and 301b.

[0254] Accordingly, one or more first groove portions 302a may be formed among the plurality of first protrusions 301a, and one or more second groove portions 302b may be formed among the plurality of second protrusions 301b.

[0255] The position of the boundary surface at the end of the adhesive layer 200 can vary depending on the modulus of the adhesive material used for the adhesive layer 200.

[0256] In addition, the position of the boundary surface of the end of the adhesive layer 200 may vary depending on whether the end trimming process of the foldable stack 2 is performed.

[0257] Reference Figure 9c The first pattern layer 300a on the first substrate 100a and the second pattern layer 300b on the second substrate 100b may have the same pattern or the same shape. For example, the first pattern layer 300a on the first substrate 100a and the second pattern layer 300b on the second substrate 100b may be formed symmetrically.

[0258] like Figure 9a , Figure 9b and Figure 9c As shown, each pattern layer 300a, 300b includes multiple groove portions 302a, 302b and multiple protrusion portions 301a, 301b, thereby more effectively controlling the flow of adhesive material in the adhesive layer 200.

[0259] like Figure 10a , Figure 10b and Figure 10c As shown, the first pattern layer 300a and the second pattern layer 300b can have different patterns.

[0260] Figure 10a This shows that the boundary surface of the end of the adhesive layer 200 is aligned with the boundary surfaces of the ends of the first pattern layer 300a and the second pattern layer 300b, and Figure 10b It is shown that the boundary surface of the end of the adhesive layer 200 is set to be more inward than the boundary surfaces of the ends of the first pattern layer 300a and the second pattern layer 300b.

[0261] The position of the boundary surface at the end of the adhesive layer 200 can vary depending on the modulus of the adhesive material used for the adhesive layer 200.

[0262] In addition, the position of the boundary surface of the end of the adhesive layer 200 may vary depending on whether the end trimming process of the foldable stack 2 is performed.

[0263] Reference Figure 10c The first pattern layer 300a on the first substrate 100a and the second pattern layer 300b on the second substrate 100b can have different patterns or different shapes.

[0264] For example, the first protrusion 301a of the first pattern layer 300a and the second protrusion 301b of the second pattern layer 300b can be configured not to overlap each other.

[0265] For example, the first pattern layer 300a and the second pattern layer 300b are configured to overlap each other in a direction perpendicular to the first substrate 100a and the second substrate 100b, and the first protrusion 301a of the first pattern layer 300a and the second protrusion 301b of the second pattern layer 300b can be patterned to overlap each other in a non-perpendicular manner.

[0266] In the first protrusion 301a and the second protrusion 301b with the same pattern, when the area where the first protrusion 301a and the second protrusion 301b overlap is viewed vertically, the thickness of this area is greater than the thickness of the entire pattern layer 300a and 300b.

[0267] In pattern layers 300a and 300b with thicker areas, when the protrusions 301a and 301b of pattern layers 300a and 300b are viewed vertically, defects (e.g., unevenness) may appear around the area where they overlap.

[0268] For example, when the first protrusion 301a of the first pattern layer 300a and the second protrusion 301b of the second pattern layer 300b are configured not to overlap, the thickness of a specific area of ​​the pattern layers 300a and 300b will not increase excessively.

[0269] In other embodiments, when the first protrusion 301a of the first pattern layer 300a and the second protrusion 301b of the second pattern layer 300b are configured not to overlap, the occurrence of defects (e.g., unevenness) caused by the pattern layers 300a and 300b will be minimized even when the pattern layers 300a and 300b are viewed vertically.

[0270] Figure 10a , Figure 10b and Figure 10c This shows that individual protrusions 301a and 301b are formed on each pattern layer 300a and 300b. However, it can be as follows: Figure 11a , Figure 11b , Figure 11c and Figure 11d As shown, multiple protrusions are formed.

[0271] For example, when each pattern layer has 300... Figure 11a , Figure 11b and Figure 11c When multiple protrusions 321 are shown, the first pattern layer 300a and the second pattern layer 300b can have different patterns.

[0272] Figure 11a This shows that the boundary surface of the end of the adhesive layer 200 is aligned with the boundary surfaces of the ends of the first pattern layer 300a and the second pattern layer 300b, and Figure 11b It is shown that the boundary surface of the end of the adhesive layer 200 is set to be more inward than the boundary surfaces of the ends of the first pattern layer 300a and the second pattern layer 300b.

[0273] One or more grooves 302a, 302b may be formed between multiple protrusions 301a, 301b.

[0274] Therefore, one or more first groove portions 302a can be formed among a plurality of first protrusions 301a, and one or more second groove portions 302b can be formed among a plurality of second protrusions 301b.

[0275] The position of the boundary surface at the end of the adhesive layer 200 can vary depending on the modulus of the adhesive material used for the adhesive layer 200.

[0276] In addition, the position of the boundary surface of the end of the adhesive layer 200 may vary depending on whether the end trimming process of the foldable stack 2 is performed.

[0277] like Figure 11a , Figure 11b , Figure 11c and Figure 11d As shown, each pattern layer 300a, 300b includes multiple groove portions 302a, 302b and multiple protrusion portions 301a, 301b, thereby more effectively controlling the flow of adhesive material in the adhesive layer 200.

[0278] Reference Figure 11c The first pattern layer 300a on the first substrate 100a and the second pattern layer 300b on the second substrate 100b can have different patterns or different shapes.

[0279] For example, the first protrusion 301a of the first pattern layer 300a and the second protrusion 301b of the second pattern layer 300b can be configured not to overlap each other.

[0280] For example, the first pattern layer 300a and the second pattern layer 300b are configured to overlap each other in a direction perpendicular to the first substrate 100a and the second substrate 100b, and the first protrusion 301a of the first pattern layer 300a and the second protrusion 301b of the second pattern layer 300b can be patterned to overlap each other in a non-perpendicular manner.

[0281] Therefore, when viewed vertically, the first protrusion 301a of the first pattern layer 300a and the second groove 302b of the second pattern layer 300b can be formed to overlap each other, and the first groove 302a of the first pattern layer 300a and the second protrusion 301b of the second pattern layer 300b can be formed to overlap each other.

[0282] As described above, in the patterned layers 300a and 300b with thick partial areas, when the protrusions 301a and 301b of the patterned layers 300a and 300b are viewed vertically, defects (e.g., unevenness) may appear around the area where they overlap.

[0283] According to this disclosure, when the first protrusion 301a of the first pattern layer 300a and the second protrusion 301b of the second pattern layer 300b are configured not to overlap, the thickness of a specific area of ​​the pattern layers 300a and 300b will not increase excessively.

[0284] In other embodiments, when the first protrusion 301a of the first pattern layer 300a and the second protrusion 301b of the second pattern layer 300b are configured not to overlap, the occurrence of defects (e.g., unevenness) caused by the pattern layer 300 will be minimized even when the pattern layers 300a and 300b are viewed vertically.

[0285] Reference Figure 11d One or more of the first protrusion 301a and the second protrusion 301b may be formed with a discontinuous pattern along the edge portion of the substrate 100.

[0286] When a portion of the protrusions 301a and 301b has a discontinuous pattern rather than a continuous pattern along the edge of the substrate 100, the pattern layer 300 may be less affected by folding stress.

[0287] Therefore, when at least one of the protrusions 301a, 301b has a discontinuous pattern, the folding stress applied to the foldable patterned layer 300a, 300b may be reduced compared to when all the protrusions 301a, 301b have a continuous pattern.

[0288] The substrate 100 in the aforementioned foldable stack 2 can be one or more of a coating, a cover window, a protective layer, and a polarizing layer.

[0289] Therefore, the foldable stack 2 in the above embodiments can be disposed on one surface of the display panel and stacked on top of each other to form a foldable display device 1.

[0290] The foldable stacking in the implementation can be described as follows.

[0291] The foldable stack in the embodiment includes: a substrate; a patterned layer disposed along an edge portion of the substrate and including one or more protrusions; and an adhesive layer disposed on the substrate and covering at least a portion of the patterned layer.

[0292] In some embodiments, the protrusion may be placed along the edge portion.

[0293] In some embodiments, the adhesive layer may directly contact the substrate and the pattern layer.

[0294] In several embodiments, the pattern layer includes a body portion and at least one protrusion on the body portion, and the at least one protrusion may be spaced inwardly from the end of the body portion by a predetermined distance.

[0295] The foldable stack in the embodiment includes: a first substrate; a first pattern layer disposed along an edge portion of the first substrate; an adhesive layer covering at least a portion of the first substrate and the first pattern layer; a second substrate disposed on the adhesive layer; and a second pattern layer disposed between the adhesive layer and the second substrate and disposed along an edge portion of the second substrate. The first pattern layer includes one or more first protrusions, and the second pattern layer includes one or more second protrusions.

[0296] In some embodiments, the second pattern layer may be configured to correspond to the first pattern layer.

[0297] In several embodiments, a first protrusion is provided along the edge portion of a first substrate, and a second protrusion is provided along the edge portion of a second substrate.

[0298] In some embodiments, the adhesive layer may directly contact the first substrate, the first patterned layer, the second substrate, and the second patterned layer.

[0299] In some embodiments, the first pattern layer and the second pattern layer may have the same shape.

[0300] In some embodiments, the first pattern layer and the second pattern layer may have different shapes.

[0301] In several embodiments, one or more first protrusions of the first pattern layer and one or more second protrusions of the second pattern layer may be configured not to overlap each other.

[0302] In several embodiments, one or more of the first protrusions have a discontinuous pattern along the edge portion of the first substrate; and / or one or more of the second protrusions have a discontinuous pattern along the edge portion of the second substrate.

[0303] The foldable stack in the embodiment includes: a substrate; a patterned layer, the patterned layer being disposed along an edge portion on the substrate and including a body portion, a plurality of protrusions disposed on the body portion and a groove portion disposed between the plurality of protrusions; and an adhesive layer, the adhesive layer being disposed on the substrate, and the ends of the adhesive layer overlapping the groove portions.

[0304] In some embodiments, one or more of the protrusions are configured to be further inward than the end of the body portion.

[0305] In some embodiments, the groove portion has an inverted triangular, inverted trapezoidal, or semi-circular cross-section.

[0306] In some embodiments, the shape of the cross-section of the groove is determined by the modulus of the adhesive material in the adhesive layer.

[0307] The foldable display device in the embodiment can be described as follows.

[0308] The foldable display device in the embodiment includes: the foldable stack in the embodiment and a display panel disposed on one surface of the foldable stack.

[0309] In several embodiments, the substrate may be one or more of a coating, a cover window, a protective layer, and a polarizing layer.

[0310] One embodiment of the manufacturing method of the foldable stack can be described as follows.

[0311] The manufacturing method of the foldable stack in the embodiment includes: first printing a plurality of lower pattern layers spaced apart from each other along an edge portion of a substrate; secondly printing an upper pattern layer to cover the plurality of lower pattern layers; and forming an adhesive layer to cover the substrate and at least a portion of the upper and lower pattern layers.

[0312] In some embodiments, the patterned layer to which the lower and upper patterned layers are stacked may include a plurality of protrusions.

[0313] In several embodiments, grooves may be formed on the pattern layer, and the grooves may have a cross-section of one of an inverted triangle, an inverted trapezoid, and a semicircle.

[0314] In some embodiments, the ends of the adhesive layer may be formed and provided such that the ends overlap with the groove portion.

[0315] It will be apparent to those skilled in the art that various modifications and variations can be made to the foldable stacked and foldable display devices and manufacturing methods of this disclosure without departing from the technical spirit or scope thereof. Therefore, this disclosure is intended to cover such modifications and variations as long as they fall within the scope of the appended claims and their equivalents.

Claims

1. A foldable stack, comprising: substrate; A patterned layer extends around the entire periphery of the substrate and is disposed on the substrate along an edge portion thereon, and includes a body portion, a plurality of protrusions on the body portion, and a groove portion disposed between the plurality of protrusions. as well as An adhesive layer disposed on the substrate and covering at least a portion of the pattern layer. The body portion includes a first surface facing the substrate and a second surface opposite the first surface and provided with the plurality of protrusions. The end of the boundary of the adhesive layer overlaps with the groove portion.

2. The foldable stack according to claim 1, wherein, The plurality of protrusions are arranged along the edge portion.

3. The foldable stack according to claim 1, wherein, The adhesive layer is in direct contact with the substrate and the pattern layer.

4. The foldable stack according to claim 1, wherein, One or more of the protrusions are spaced inwardly at a predetermined distance from the end of the body portion.

5. A foldable stack, comprising: First substrate; A first pattern layer extends around the entire periphery of the first substrate and is disposed on the first substrate along the edge portion of the first substrate, and includes a first body portion, a plurality of first protrusions on the first body portion, and a first groove portion disposed between the plurality of first protrusions. An adhesive layer covering at least a portion of the first substrate and the first patterned layer; A second substrate disposed on the adhesive layer, wherein the adhesive layer is disposed between the first substrate and the second substrate; and A second pattern layer is disposed between the adhesive layer and the second substrate, extending around the entire periphery of the second substrate and partially disposed on the edge of the second substrate, and includes a second body portion, a plurality of second protrusions on the second body portion, and second groove portions disposed between the plurality of second protrusions. The first body portion includes a first surface facing the first substrate and a second surface opposite the first surface and provided with the plurality of first protrusions. The second body portion includes a third surface facing the second substrate and a fourth surface opposite the third surface on which the plurality of second protrusions are provided. The boundary of the adhesive layer overlaps with the first groove and the second groove.

6. The foldable stack according to claim 5, wherein, The second pattern layer is configured to correspond to the first pattern layer.

7. The foldable stack according to claim 5, wherein, The first protrusion is disposed along the edge portion of the first substrate, and the second protrusion is disposed along the edge portion of the second substrate.

8. The foldable stack according to claim 5, wherein, The adhesive layer is in direct contact with the first substrate, the first pattern layer, the second substrate, and the second pattern layer.

9. The foldable stack according to claim 5, wherein, The first pattern layer and the second pattern layer have the same shape.

10. The foldable stack according to claim 5, wherein, The first pattern layer and the second pattern layer have different shapes.

11. The foldable stack according to claim 10, wherein, One or more of the first protrusions in the first patterned layer and one or more of the second protrusions in the second patterned layer are configured not to overlap each other.

12. The foldable stack according to claim 5, wherein, One or more of the first protrusions have a discontinuous pattern along the edge portion of the first substrate; And / or One or more of the second protrusions have a discontinuous pattern along the edge portion of the second substrate.

13. A foldable stack, comprising: substrate; A patterned layer extends around the entire periphery of the substrate and is disposed on the substrate along an edge portion of the substrate, and includes a body portion, a plurality of protrusions disposed on the body portion, and a groove portion disposed between the plurality of protrusions and recessed toward the body portion. as well as An adhesive layer is disposed on the substrate, and the ends of the adhesive layer overlap the trench portion. The body portion includes a first surface facing the substrate and a second surface opposite the first surface and provided with the plurality of protrusions.

14. The foldable stack according to claim 13, wherein, One or more of the plurality of protrusions are configured to be more inwardly directed than the end of the body portion.

15. The foldable stack according to claim 13, wherein, The groove has an inverted triangular, inverted trapezoidal, or semi-circular cross-section.

16. The foldable stack according to claim 15, wherein, The shape of the cross-section of the groove is determined by the modulus of the adhesive material in the adhesive layer.

17. A foldable display device, comprising: Foldable stack according to any one of claims 1 to 16; as well as A display panel is disposed on one surface of the foldable stack.

18. The foldable display device according to claim 17, wherein, The substrate in the foldable stack is one or more of a coating, a cover window, a protective layer, and a polarizing layer.

19. A method for manufacturing a foldable and stackable structure, comprising: The plurality of lower pattern layers are first printed on the substrate along the edge portion of the substrate in a manner that the plurality of lower pattern layers are spaced apart from each other, and the plurality of lower pattern layers extend around the entire periphery of the substrate; Next, the upper pattern layer is printed to cover the plurality of lower pattern layers; as well as An adhesive layer is formed to cover the substrate and at least a portion of the upper pattern layer and the lower pattern layer. The end of the adhesive layer is formed and configured such that the end overlaps with a groove formed on the pattern layer on which the lower pattern layer and the upper pattern layer are stacked.

20. The manufacturing method according to claim 19, wherein, The stacked pattern layer, comprising the lower and upper pattern layers, includes multiple protrusions.

21. The manufacturing method according to claim 20, wherein, The groove has a cross-section that is one of an inverted triangle, an inverted trapezoid, or a semicircle.

22. The manufacturing method according to claim 21, wherein, Adjusting the width of the plurality of lower pattern layers adjusts the position of the space between the plurality of lower pattern layers, thereby adjusting the position of the groove portion.

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