Display device and method of manufacturing the same

Abstract

A display device and a manufacturing method thereof are provided. An embodiment relates to a display device including a window portion, an adhesive layer, and a display module. A curved region and a non-curved region are defined in the window portion. The adhesive layer includes a first adhesive portion overlapping the curved region and a second adhesive portion overlapping the non-curved region. The adhesive layer is directly disposed on the window portion. The display module is directly disposed on the adhesive layer. The first adhesive portion is formed by curing a first resin including a first photoinitiator that initiates a reaction by first light. The second adhesive portion is formed by curing a second resin including a second photoinitiator that initiates a reaction by second light having a different central wavelength than the first light or a thermal initiator. Thus, the display device according to an embodiment has high durability and excellent recognition.

Description

Technical Field

[0001] This invention relates to a flexible display device, and more specifically to a flexible display device and a method for manufacturing the same. Background Technology

[0002] Display devices can be used in mobile devices such as smartphones, tablets, laptops, digital cameras, camcorders, and portable information terminals, or in electronic products such as ultra-thin televisions, display monitors, and billboards.

[0003] Recently, flexible display devices have been developed that are easy to carry and can be adapted to devices of various shapes. For example, display devices that include a curved area and a non-curved area extending from the curved area have been developed. Summary of the Invention

[0004] One object of the present invention is to provide a display device with high durability and excellent recognizability, and a method for manufacturing the same.

[0005] An embodiment of the present invention relates to a display device that may include: a window portion defining a curved region and a non-curved region; an adhesive layer including a first adhesive portion overlapping the curved region and a second adhesive portion overlapping the non-curved region, the adhesive layer being directly disposed on the window portion; and a display module being directly disposed on the adhesive layer. The first adhesive portion may be formed by curing a first resin comprising a first photoinitiator that generates an initiation reaction using a first light. The second adhesive portion may be formed by curing a second resin comprising a second photoinitiator or a thermal initiator, wherein the second photoinitiator generates an initiation reaction using a second light having a center wavelength different from the first light.

[0006] It is possible that the difference in the center wavelengths of the first light and the second light is greater than 50 nm.

[0007] It is possible that the range of the center wavelength of the first light is selected from the range of 200nm to 300nm and the range of 300nm to 400nm, and the range of the center wavelength of the second light is the remaining range.

[0008] The first photoinitiator may comprise at least one compound represented by one of the first group and the second group described below, and the second photoinitiator may comprise at least one compound represented by the remaining group:

[0009] [Group 1]

[0010] 2,2-Dimethoxy-2-phenylacetophenone, (η6-cumene)(η5-cyclopentadienyl)ferric hexafluorophosphate, 2-hydroxy-2-methylphenylacetone, [4-(2-hydroxytetradecoxy)phenyl]phenyliodonium hexafluoroantimonate, 2-isopropylthioxanthone;

[0011] [Group 2]

[0012] 2-Methyl-4'-(methylthio)-2-morpholinophenylacetone, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyroylbenzene, diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide.

[0013] Alternatively, the display device may have a hole that penetrates the display module and the adhesive layer and overlaps with the non-curved area on a plane.

[0014] Alternatively, the adhesive layer may further include a third adhesive portion disposed between the first adhesive portion and the second adhesive portion, and overlapping the non-bending region. Alternatively, the third adhesive portion may be formed by curing a third resin comprising the first photoinitiator and the second photoinitiator.

[0015] Alternatively, the third resin may be a resin formed by the mutual diffusion of the first resin and the second resin, wherein the first photoinitiator and the second photoinitiator have a concentration gradient in the third resin.

[0016] Alternatively, the first adhesive portion may not include the second photoinitiator, and the second adhesive portion may not include the first photoinitiator.

[0017] The display module may include: a substrate; a light-emitting element layer disposed on the substrate; and a thin-film encapsulation layer disposed directly on the light-emitting element and sealing the light-emitting element.

[0018] Alternatively, the curved region may include a first curved region and a second curved region, and the non-curved region may be defined between the first curved region and the second curved region.

[0019] An embodiment of the present invention relates to a display device that may include a window, a display module, and an adhesive layer. The window may include: a first window having a curved shape; and a second window extending from the first window and having a flat shape. The display module may include: a first portion overlapping the first window; and a second portion overlapping the second window, wherein a hole through the second portion may be defined in the display module. The adhesive layer may include: a first adhesive portion disposed between the first window and the first portion; and a second adhesive portion disposed between the second window and the second portion. The first adhesive portion may be formed by curing a first resin comprising a first photoinitiator that generates an initiation reaction using first light. The second adhesive portion may be formed by curing a second resin comprising a second photoinitiator, wherein the second photoinitiator generates an initiation reaction using second light having a center wavelength different from the first light.

[0020] It is possible that the second photoinitiator is less reactive to the first light than the first photoinitiator is to the first light.

[0021] An embodiment of the present invention relates to a method for manufacturing a display device, which may include: providing a display module having a first region and a second region defined thereon; applying a first resin comprising a first initiator to the first region of the display module; applying a second resin comprising a second initiator different from the first initiator to the second region of the display module; curing the first resin to achieve a curing rate of 50% or more and 80% or less, thereby forming a first pre-adhesive layer; aligning a window having a curved region and a non-curved region with the display module; and bonding the display module and the window.

[0022] Alternatively, the method for manufacturing the display device may further include the step of curing the second resin to achieve a curing rate of 10% or more and 40% or less, thereby forming a second pre-adhesive layer.

[0023] Alternatively, the display module may further include a hole defined in the second region, wherein the second resin is coated on a plane that does not overlap with the hole.

[0024] The step of forming the first pre-adhesive layer may include irradiating the first resin and the second resin with light. During the irradiation step, the first resin is cured to a curing rate of 50% or more and 80% or less, and the second resin is cured to a curing rate of 40% or less.

[0025] Alternatively, the manufacturing method of the display device may further include, after the step of bonding the display module and the window, a formal curing step of curing the first pre-adhesive layer and the second resin to achieve a curing rate of 90% or more and 100% or less.

[0026] The step of aligning the window with the display module may include: aligning the curved area of ​​the window with the first area of ​​the display module, and aligning the non-curved area of ​​the window with the second area of ​​the display module.

[0027] Alternatively, the first resin and the second resin can be coated by inkjet printing.

[0028] (Invention Effects)

[0029] An embodiment of the present invention relates to a display device that can have high durability and excellent readability.

[0030] According to an embodiment of the present invention, a method for manufacturing a display device can provide a display device with high durability and excellent recognizability. Attached Figure Description

[0031] Figure 1 This is a perspective view of a display device according to an embodiment.

[0032] Figure 2 This is an exploded perspective view of a display device according to an embodiment.

[0033] Figure 3a It is along Figure 1 A cross-sectional view of the display device taken by the I-I' line.

[0034] Figure 3b This is a cross-sectional view of a display device according to an embodiment.

[0035] Figure 4 This is a cross-sectional view of a display module according to one embodiment.

[0036] Figure 5 and Figure 6 This is a cross-sectional view illustrating a method of manufacturing a display device according to an embodiment.

[0037] Figure 7 This is a graph showing the absorbance of the photoinitiator involved in one embodiment.

[0038] Figures 8a to 14 This is a cross-sectional view illustrating a method of manufacturing a display device according to an embodiment.

[0039] (Symbol Explanation)

[0040] DD: Display device; WD: Window; WD-B: First window; WD-F: Second window; AM: Adhesive layer; AM-B: First adhesive part; AM-F: Second adhesive part; DM: Display module; DM-B: First part; DM-F: Second part. Detailed Implementation

[0041] In this specification, when it is mentioned that a certain component (or region, layer, part, etc.) is located on, connected to or combined with other components, it means that it can be directly configured / connected / combined with other components, or a third component can be configured therein.

[0042] The same symbols refer to the same constituent elements. In addition, the thickness, proportions, and dimensions of the constituent elements in the various figures are exaggerated for the purpose of effectively illustrating the technical content.

[0043] "And / or" includes one or more combinations of all relevant constituent elements that can be defined.

[0044] The terms "first," "second," etc., can be used to describe various constituent elements, but the constituent elements described should not be limited to these terms. These terms are used only for the purpose of distinguishing one constituent element from another. For example, without departing from the scope of this invention, a first constituent element can be named a second constituent element, and similarly, a second constituent element can be named a first constituent element. Singular expressions include plural expressions unless explicitly stated otherwise in the text.

[0045] Additionally, terms such as "below," "on the lower side," "above," and "on the upper side" are used to explain the connection relationships between the components in the diagram. These terms are relative concepts and are explained based on the direction shown in the diagram.

[0046] In addition, in this specification, "configured on..." includes not only the case where it is configured on top, but also the case where it is configured on the bottom.

[0047] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) shall have the same meaning as commonly understood by those skilled in the art. Furthermore, terms defined in commonly used dictionaries shall be interpreted as having a consistent meaning in the relevant technical context, and are hereby explicitly defined, provided they are not interpreted as having an ideal or overly formal meaning.

[0048] Terms such as “including” or “having” should be understood as referring to the presence of features, figures, steps, operations, constituent elements, components, or combinations thereof as recorded in the instruction manual, and do not preclude the existence or additional possibilities of one or more other features, figures, steps, operations, constituent elements, components, or combinations thereof.

[0049] In this specification, "directly configured in..." means that the first and second constituent elements are configured without any other adhesive layers.

[0050] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0051] Figure 1 This is a perspective view of a display device DD according to an embodiment. Figure 2 This is an exploded perspective view of a display device DD according to an embodiment. Figure 3a It is along Figure 1 A cross-sectional view of the display device DD taken by the I-I' line. Figure 3b This is a cross-sectional view of a display device DD according to an embodiment. Figure 3b The text shows the relationship with... Figure 3a The corresponding cross section.

[0052] exist Figure 1 and Figure 2 The illustration shows a portable terminal where both edges are provided in a curved form. However, the embodiment is not limited to this; edges may be provided in a curved form on one side or on all four sides. Furthermore, although not shown separately, the display device DD of the present invention can be used in large electronic devices such as televisions or external billboards, as well as small and medium-sized electronic devices such as personal computers, laptops, personal digital terminals, car navigation units, game consoles, portable electronic devices, watch-type electronic devices, and cameras. These are merely illustrative examples, and can of course be applied to other electronic devices without departing from the concept of the invention.

[0053] In one embodiment, a display device DD defines multiple regions divided on a display surface IS. The display device DD may define a display area DD-DA for displaying images IM1 and IM2, a non-display area DD-NDA adjacent to the display area DD-DA, and a hole area HA. ​​In one embodiment, the non-display area DD-NDA may be omitted. Figure 1The images IM1 and IM2 illustrate a clock widget, among other things. The non-display area DD-NDA can surround the display area DD-DA. The edge of the hole area HA can be surrounded by the display area DD-DA. On the plane, the hole area HA can be far from the non-display area DD-NDA, and the display area DD-DA is located between the hole area HA and the non-display area DD-NDA. The hole area HA is defined by the hole MH (see reference). Figure 3a The area of ​​the aperture MH is thus surrounded on the plane by the display area DD-DA containing the images IM1 and IM2.

[0054] One embodiment of the display device DD may include a curved region BA and a non-curved region NBA. The curved region BA may be a region that is curved relative to a bending axis BX. The non-curved region NBA may be a flat region extending from the curved region BA. The curved region BA may be an edge region of the display device DD. The curved region BA may be defined on one side and the other side of the display device DD. In this case, the curved region BA defined on one side of the display device DD may be referred to as the first curved region, and the curved region BA defined on the other side of the display device DD may be referred to as the second curved region.

[0055] The non-curved area NBA can be parallel to the surface defined by the first direction DR1 and the second direction DR2. The normal direction of the display device DD indicates the third direction DR3. In this specification, "viewed on a plane" or "viewed on a plane" can refer to the view in the third direction DR3. The third direction DR3 is used to distinguish the front (or upper) surface and the back (or lower) surface of each layer or unit described below. However, the directions indicated by the first direction DR1 to the third direction DR3 are relative concepts and can be changed to other directions, such as the opposite directions. Hereinafter, the first direction to the third direction refers to the directions indicated by the first direction DR1 to the third direction DR3, referring to the same symbols.

[0056] exist Figure 1 and Figure 2 The example illustrates a case where two curved regions BA are defined at the edge of the display device DD, and a non-curved region NBA is defined between the two curved regions BA. However, the embodiment is not limited to this; the display device DD may define one curved region BA and one non-curved region NBA.

[0057] The curved area BA can be the area corresponding to the side of the display device DD, and the non-curved area NBA can be the area corresponding to the front surface of the display device DD.

[0058] Reference Figure 2 , Figure 3a as well as Figure 3bThe window WD can be configured on the front surface of the display module DM to protect the display module DM. For example, the window WD may include a glass substrate, a sapphire substrate, or a plastic film. The window WD can be a flexible window.

[0059] The window area WD can be divided into a transmission area TA and a border area BZA. The transmission area TA is the area through which incident light passes. The transmission area TA can be the area corresponding to the display area DD-DA. For example, the transmission area TA can overlap with the entire surface or at least a portion of the display area DD-DA. The images IM1 and IM2 of the display area DD-DA displayed on the display module DM can be identified from the outside through the transmission area TA.

[0060] The border area BZA can be an area with relatively low light transmittance compared to the transmittance area TA. The border area BZA can be the area corresponding to the non-display area DD-NDA. The border area BZA defines the shape of the transmittance area TA. The border area BZA can be adjacent to and surround the transmittance area TA.

[0061] The border area BZA can have a predetermined color. The border area BZA can cover the non-display area DD-NDA of the display module DM to prevent the non-display area DD-NDA from being identified from the outside. On the other hand, this is an example; in a window WD according to an embodiment of the present invention, the border area BZA may also be omitted.

[0062] Within the window area WD, curved regions WD-BA and non-curved regions WD-NBA can be defined. These can be regions that are essentially the same as the aforementioned curved regions BA and non-curved regions NBA.

[0063] The window portion WD may include a first window portion WD-B and a second window portion WD-F. The first window portion WD-B may be the portion corresponding to the curved region BA. The second window portion WD-F may be the portion corresponding to the non-curved region NBA. The first window portion WD-B may have a curved shape. The second window portion WD-F may have a flat shape that extends from the first window portion WD-B.

[0064] An adhesive layer AM can be disposed on the window portion WD. The adhesive layer AM can be directly disposed on the window portion WD. The adhesive layer AM may include a first adhesive portion AM-B and a second adhesive portion AM-F. The first adhesive portion AM-B may be the portion corresponding to the curved area BA, and the second adhesive portion AM-F may be the portion corresponding to the non-curved area NBA. The adhesive layer AM can bond the window portion WD and the display module DM. The first adhesive portion AM-B can be disposed between the first window portion WD-B and the first portion DM-B of the display module DM (described later), and the second adhesive portion AM-F can be disposed between the second window portion WD-F and the second portion DM-F of the display module DM (described later), thereby bonding the window portion WD and the display module DM.

[0065] The first adhesive portion AM-B can be formed by curing a first resin RS1 (described later), which includes a first photoinitiator that initiates a reaction via a first light. The second adhesive portion AM-F can be formed by curing a second resin RS2 (described later), which includes a second photoinitiator or a thermal initiator that initiates a reaction via a second light. Therefore, the first adhesive portion AM-B and the second adhesive portion AM-F can have different compositions. The first adhesive portion AM-B may include a product of the curing reaction of the first photoinitiator with the base resin, and the second adhesive portion AM-F may include a product of the curing reaction of the second photoinitiator with the base resin, or a product of the curing reaction of a thermal initiator with the base resin. The first light L1 and the second light L2 may have different center wavelengths. Detailed descriptions of the first light L1, the second light L2, the first photoinitiator, and the second photoinitiator will be given later.

[0066] Reference Figure 3b In one embodiment, the adhesive layer AM may further include a third adhesive portion AM-F1. The third adhesive portion AM-F1 may be disposed between the first adhesive portion AM-B and the second adhesive portion AM-F, and overlaps with the non-bending region NBA. The third adhesive portion AM-F1 can be formed by curing a third resin RS3 comprising a first photoinitiator and a second photoinitiator. Thus, the third adhesive portion AM-F1 may include the curing reaction product of the first photoinitiator, the second photoinitiator, and the base resin.

[0067] The display module DM may include a first part DM-B and a second part DM-F. The first part DM-B may be the part corresponding to the curved region BA, and the second part DM-F may be the part corresponding to the non-curved region NBA. The first part DM-B may overlap with the first window WD-B, and the second part DM-F may overlap with the second window WD-F.

[0068] Reference Figure 2 , Figure 3a and Figure 3bA hole MH can be defined that connects the display module DM and the adhesive layer AM. Hole MH can overlap with the hole region HA. Hole MH can include the adhesive layer hole MH-AM defined in the adhesive layer AM and the display module hole MH-DM defined in the display module DM. Hole MH can house electronic modules. For example, hole MH can house electronic modules such as camera modules and infrared sensing modules.

[0069] Reference Figure 1 and Figure 2 The display device DD may also include a storage component BC. The storage component BC can be integrated with the window WD. The storage component BC provides the back of the display device DD. The storage component BC can be integrated with the window WD to define the interior space.

[0070] The storage component BC can stably protect the various components of the display device DD housed within the internal space from external impacts. The internal space provided by the storage component BC can accommodate the display module DM, electronic modules, etc.

[0071] Figure 4 This is a cross-sectional view capturing a portion of the display module DM. (See reference...) Figure 4 One embodiment of the display module DM may include a substrate layer BS, a circuit layer CL, a light-emitting element layer ED, and a thin-film encapsulation layer TFE.

[0072] The substrate BS can be an insulating substrate. The substrate BS can be provided in a flexible state. For example, the substrate BS can be a flexible substrate comprising polyimide (PI). However, the embodiments are not limited to this, and the substrate BS can also be made of various materials such as glass and plastic. The plastic substrate can include at least one of acrylic resins, methacrylic resins, polyisoprene, ethylene resins, epoxy resins, polyurethane resins, cellulose resins, siloxane resins, polyimide resins, polyamide resins, and dinaphthalene-based resins.

[0073] The circuit layer CL can be disposed on the substrate layer BS. The circuit layer CL may include transistors and multiple insulating layers that insulate the transistors. The multiple insulating layers may each include organic and / or inorganic materials, and may have a single-layer or stacked structure.

[0074] The light-emitting element layer ED can be disposed on the circuit layer CL. Although not illustrated, the light-emitting element layer ED may include an organic electroluminescent element. The organic electroluminescent element may include a cathode, an anode, and a light-emitting layer disposed between the cathode and the anode. The organic electroluminescent element may also include a hole transport layer disposed between the anode and the light-emitting layer and an electron transport layer disposed between the cathode and the light-emitting layer. The organic electroluminescent element may also include a capping layer disposed on the cathode. The light-emitting layer may include an organic light-emitting material, but the embodiments are not limited thereto. For example, the light-emitting element may be a quantum dot light-emitting element in which quantum dots are included in the light-emitting layer.

[0075] A thin-film encapsulation layer (TFE) can be disposed on the light-emitting element layer (ED) to cover the light-emitting element. The TFE can include at least one inorganic layer and at least one organic layer. For example, the TFE can have a stacked structure of inorganic / organic / inorganic layers. The TFE can prevent moisture or air from penetrating into the light-emitting element.

[0076] The input sensing layer (ISL) can be disposed on the thin-film encapsulation layer (TFE). The input sensing layer (ISL) can be formed on the TFE through a continuous process. The input sensing layer (ISL) can also be directly disposed on the TFE. The input sensing layer (ISL) can sense external input. The input sensing layer (ISL) can be a capacitive input sensing layer that senses changes in capacitance caused by external objects, or a pressure-sensing input sensing layer that senses changes in pressure caused by external objects.

[0077] The following is for reference Figures 5 to 14 This document details a method for manufacturing a display device DD according to an embodiment. Hereinafter, references and other details will be omitted. Figures 1 to 4 Detailed description of the constituent elements that are the same as those described.

[0078] Figure 5 and Figure 6 The steps of coating a first resin RS1 and a second resin RS2 in a method for manufacturing a display device DD according to one embodiment are briefly illustrated. The method for manufacturing a display device DD according to one embodiment includes the steps of providing a display module DM, coating the display module DM with the first resin RS1, and coating the display module DM with the second resin RS2.

[0079] The display module DM can define a first region DP-BA and a second region DP-NBA. The first region DP-BA can be the portion that is subsequently bonded to the window portion WD and bent, while the second region DP-NBA can be the portion that is subsequently bonded to the window portion WD and is not bent. That is, the first region DP-BA can be the region corresponding to the aforementioned bent region BA, and the second region DP-NBA can be the region corresponding to the aforementioned unbent region NBA. A first resin RS1 can be applied to the first region DP-BA of the display module DM, and a second resin RS2 can be applied to the second region DP-NBA of the display module DM. Thus, the first resin RS1 can be applied to overlap with the first region DP-BA of the display module DM on a plane, and the second resin RS2 can be applied to overlap with the second region DP-NBA of the display module DM on a plane. The second resin RS2 can be applied to not overlap with the display module hole MH-DM on a plane.

[0080] There are no particular restrictions on the coating methods for the first resin RS1 and the second resin RS2, such as... Figure 5 and Figure 6 As shown, the coating can be applied using an inkjet printing device (IP). When coating the first resin RS1 and the second resin RS2 using an inkjet printing method, a separate mask is not required, which reduces the amount of resin used, thereby reducing process time and costs.

[0081] The first resin RS1 and the second resin RS2 may have different compositions from each other. The first resin RS1 may include a first initiator, and the second resin RS2 may include a second initiator. The first initiator and the second initiator may be different initiators. The first resin RS1 may not include a second initiator, and the second resin RS2 may not include a first initiator. The first initiator may be emitted by a first light source L1 (refer to...). Figure 8a The first photoinitiator reacts with a second photoinitiator, which is different from the first photoinitiator L1 (see reference). Figure 10 The photoinitiator is either a second photoinitiator that reacts with light L1 or a thermal initiator that reacts with heat. The reactivity of the second photoinitiator with respect to the first light L1 may be lower than that of the first photoinitiator with respect to the first light L1. The first light L1 may have high reactivity with the first photoinitiator and low reactivity with the second photoinitiator. The second light L2 may have high reactivity with the second photoinitiator and low reactivity with the first photoinitiator.

[0082] Preferably, the difference in center wavelength between the first light L1 and the second light L2 is greater than 50 nm. For example, the difference in center wavelength between the first light L1 and the second light L2 can be greater than 50 nm and less than 200 nm. When the difference in center wavelength between the first light L1 and the second light L2 is less than 50 nm, the second resin RS2 may also be cured at a relatively fast rate during the period when the first resin RS1 is cured by the first light L1.

[0083] The center wavelength range of the first light L1 is selected from either the range of 200 nm to 300 nm or the range of 300 nm to 400 nm, and the center wavelength range of the second light L2 can be any of the remaining ranges. For example, the center wavelength range of the first light L1 can be 200 nm to 300 nm, and the center wavelength range of the second light L2 can be 300 nm to 400 nm.

[0084] The first photoinitiator may include at least one compound represented by any one of the first group and the second group below, and the second photoinitiator may include at least one compound represented by the remaining group. For example, the first photoinitiator may include at least one compound represented by the first group below, and the second photoinitiator may include at least one compound represented by the second group below.

[0085] [Group 1]

[0086] 2,2-Dimethoxy-2-phenylacetophenone, (η6-cumene)(η5-cyclopentadienyl)ferric hexafluorophosphate, 2-hydroxy-2-methylphenylacetone, [4-(2-hydroxytetradecoxy)phenyl]phenyliodonium hexafluoroantimonate, 2-isopropylthioxanthone;

[0087] [Group 2]

[0088] 2-Methyl-4'-(methylthio)-2-morpholinophenylacetone, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyroylbenzene, diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide.

[0089] Figure 7 This is a graph showing the absorbance of photoinitiators comprising at least one of the compounds from Group 1 or Group 2. (See reference) Figure 7It can be confirmed that photoinitiators including at least one of the compounds in the first group, such as IRGACURE 651 (2,2-dimethoxy-2-phenylacetophenone), IRGACURE 261 ((η6-cumene)(η5-cyclopentadienyl)ferric hexafluorophosphate), DAROCURE 1173 (2-hydroxy-2-methylphenylacetone), CD1012 ([4-(2-hydroxytetradecoxy)phenyl]phenyliodonium hexafluoroantimonate), and ITX (2-isopropylthioxanthone), have high absorbance A in the wavelength range of above 200 nm and below 300 nm. In addition, it can be confirmed that photoinitiators including at least one of the compounds in the second group, such as DAROCURE TPO (2-methyl-4'-(methylthio)-2-morpholinophenylacetone), IRGACURE 907 (2-benzyl-2-(dimethylamino)-4'-morpholinobutyroylbenzene), and IRGACURE 369 (diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide), have high absorbance A in the wavelength range of above 300 nm and below 400 nm.

[0090] In one embodiment, the first resin RS1 and the second resin RS2 may comprise a photocurable base resin such as a curable monomer or a photocurable oligomer. When the second resin RS2 comprises a thermocurable agent, it may comprise a thermocurable base resin such as a thermocurable monomer or a thermocurable oligomer. For example, the first resin RS1 and the second resin RS2 may comprise a base resin such as an acrylic monomer or an acrylic oligomer. The first resin RS1 and the second resin RS2 may also comprise a crosslinking agent.

[0091] Figure 8 to Figure 14 The steps of forming an adhesive layer AM to bond the display module DM and the window WD in a manufacturing method of a display device DD according to one embodiment are briefly illustrated.

[0092] Reference Figure 8a , Figure 8b and Figure 9 One embodiment of the manufacturing method of the display device DD includes the step of curing a first resin RS1 to form a first pre-adhesive layer RS11. (See also...) Figure 8a The first light L1 can be irradiated onto the front surfaces of the coated first resin RS1 and second resin RS2. (Refer to...) Figure 9 The first resin RS1, including the first photoinitiator, can be cured by the first light L1. By the first light L1, the first resin RS1 can be cured to a cure rate of approximately 50% to 80%, thereby forming the first pre-adhesive layer RS11. (Refer to...) Figure 9The second resin RS2, including a second photoinitiator or a thermal initiator, can be cured by the first light L1 to have a curing rate of less than 40%, or may not cure at all. Therefore, the first resin RS1 can be selectively cured without a separate mask, thus reducing process costs and time.

[0093] Reference Figure 8b A third resin RS3 can be formed between the first resin RS1 and the second resin RS2. The third resin RS3 can be a resin formed by the interdiffusion of the first resin RS1 and the second resin RS2. Therefore, the third resin RS3 includes both a first initiator and a second initiator. In the third resin RS3, the first initiator and the second initiator can have a concentration gradient. The concentration of the first initiator can be higher closer to the first resin RS1 and lower closer to the second resin RS2. The concentration of the second initiator can be higher closer to the second resin RS2 and lower closer to the first resin RS1. Therefore, when irradiated with the first light L1, the third resin RS3 can be cured to a degree of curing that is higher closer to the first resin RS1 and lower closer to the second resin RS2. In this case, the degree of curing gradually increases between the first pre-adhesive layer RS11 and the second pre-adhesive layer RS21. Therefore, damage to the boundary between the first pre-adhesive layer RS11 and the second pre-adhesive layer RS21 due to a sharp difference in degree of curing can be prevented. Furthermore, since there is a concentration gradient between the first and second initiators in the third resin RS3, the phenomenon of stains being identified due to abrupt differences in composition can be prevented. Depending on the process, the third resin RS3 may not be formed.

[0094] The following describes a method for manufacturing a display device DD based on an example in which the third resin RS3 is not formed.

[0095] Reference Figure 10 and Figure 11 One embodiment of the manufacturing method of the display device DD may further include the step of curing the second resin RS2 to form the second pre-adhesive layer RS21.

[0096] Reference Figure 10 The second light L2 can be irradiated onto the front surfaces of the first pre-adhesive layer RS11 and the second resin RS2. (Refer to...) Figure 11 The second resin RS2, including the second photoinitiator, can be cured by the second light L2. By the second light L2, the second resin RS2 can be cured to a cure rate of approximately 10% to 40%, forming a second pre-adhesive layer RS21. Although not illustrated, in cases where the second resin RS2 includes a thermal initiator, a predetermined heat may be applied instead of the second light L2. (Refer to...) Figure 10The first resin RS1, including the first photoinitiator, will not be cured by the second light L2.

[0097] Although not illustrated, the second resin RS2 can be cured at a low rate by the first light L1. For example, while the first resin RS1 is curing to a cure rate of about 50% to 80%, the second resin RS2 can be cured to a cure rate of about 10% to 40%, thereby forming the second pre-adhesive layer RS21. Alternatively, even if the second photoinitiator does not react with the first light L1, the second resin RS2 can be cured naturally to a cure rate of about 10% to 40%, thereby forming the second pre-adhesive layer RS21. In this case, the step of irradiating with the second light L2 can be omitted.

[0098] In one embodiment, the step of forming the second pre-adhesive layer RS21 can be omitted. That is, the second resin RS2 can also be directly bonded to the window.

[0099] Reference Figure 12 and Figure 13 One embodiment of the manufacturing method of the display device DD may include: aligning the window WD with the display module DM; and bonding the display module DM and the window WD.

[0100] Reference Figure 12 The steps of aligning the window WD with the display module DM may include the following steps: aligning the curved area WD-BA of the window WD with the first area DP-BA of the display module DM, and aligning the non-curved area WD-NBA of the window WD with the second area DP-NBA of the display module DM.

[0101] Thus, bonding can be performed so that the first window portion WD-B and the first part DM-B correspond, and the second window portion WD-F and the second part DM-F correspond.

[0102] In the manufacturing method of a flexible display device, when bonding the window and the display module, it is necessary to bond the bent portion of the window to the display module more firmly than the flat portion of the window. Otherwise, due to the force acting on the bent portion, the bond between the window and the display module may fall off or become weak. Therefore, the durability of the manufactured display device may decrease. On the other hand, in the manufacturing method of a flexible display device, the resin may bend when it is applied to the display module. In particular, when the display module has defined holes, bending may occur along the boundary of the hole area. For example, protrusions may form in the resin along the boundary of the hole area. In this case, if the resin has a high curing rate of 50% or more, the subsequent bonding of the display module and the window may not achieve the desired flattening. Therefore, the adhesion between the display module and the window may be reduced or the adhesive layer may form unevenly, potentially leading to the detection of stains and other defects, thus reducing readability.

[0103] According to one embodiment of the manufacturing method of the display device DD, the first pre-adhesive layer RS11 has a high curing rate and therefore strong adhesive force. Thus, the first portion DM-B of the display module DM can be firmly bonded to the first window WD-B. Therefore, it is possible to prevent the adhesive between the first portion DM-B and the first window WD-B from detaching or becoming weakly bonded. Furthermore, in one embodiment, the second pre-adhesive layer RS21 has a low curing rate, so when bonding the display module DM and the window WD, the bends generated in the second pre-adhesive layer RS21 can be flattened. Even if the adhesive force of the second pre-adhesive layer RS21 is low due to its low curing rate, it will still bond the flat second portion DM-F and the second window WD-F without detachment. Therefore, the display device DD manufactured by the manufacturing method of the display device DD according to one embodiment can have high durability and excellent readability.

[0104] Reference Figure 13 and Figure 14 One embodiment of the manufacturing method of the display device DD may further include a formal curing step.

[0105] The formal curing step can be as follows: irradiating with a third light L3 to cure the first pre-adhesive layer RS11 and the second pre-adhesive layer RS21, or the first pre-adhesive layer RS11 and the second resin RS2, to a curing rate of 90% or more and 100% or less. The adhesive layer AM can be formed after this formal curing step. The third light L3 may include a first light L1 and a second light L2, and irradiating with the third light L3 may mean simultaneously irradiating the first light L1 and the second light L2.

[0106] One embodiment of the display device includes an adhesive layer comprising a first adhesive portion having a first photoinitiator and a second adhesive portion having a second photoinitiator. Therefore, the display device of one embodiment can be configured to have high durability and excellent readability. A method for manufacturing the display device of one embodiment may include: applying a first resin and a second resin onto a display module; and curing the first resin to form a first pre-adhesive layer with a curing rate of 50% or more and 80% or less. Therefore, the method for manufacturing the display device of one embodiment can provide a display device with high durability and excellent readability.

[0107] The embodiments have been described with reference to examples; however, those skilled in the art should understand that various modifications and variations can be made to the invention without departing from the spirit and scope of the invention as set forth in the claims. Furthermore, the embodiments disclosed herein are not intended to limit the technical concept of the invention, and should be interpreted as including all technical concepts within the scope of the claims and their equivalents within the scope of the invention.

Claims

1. A display device, comprising: The window area is defined by both curved and non-curved regions. An adhesive layer, comprising a first adhesive portion overlapping the curved region and a second adhesive portion overlapping the non-curved region, is directly disposed on the window portion. The adhesive layer further comprises a third adhesive portion disposed between the first and second adhesive portions and overlapping the non-curved region. The display module is directly mounted on the adhesive layer. The first adhesive portion is formed by curing a first resin, including a first photoinitiator that generates an initiation reaction using first light. The second adhesive portion is formed by curing a second resin, including a second photoinitiator or a thermal initiator, wherein the second photoinitiator generates an initiation reaction using a second light having a center wavelength different from the first light.

2. The display device according to claim 1, wherein, The difference in the center wavelength between the first light and the second light is greater than 50 nm.

3. The display device according to claim 1, wherein, The range of the center wavelength of the first light is selected from the range of 200nm and 300nm and the range of 300nm and 400nm, and the range of the center wavelength of the second light is selected from the range of 200nm and 300nm and the range of 300nm and 400nm.

4. The display device according to claim 1, wherein, The first photoinitiator comprises at least one compound represented by one of the first group and the second group described below, and the second photoinitiator comprises at least one compound represented by the other group of the first group and the second group described below: [Group 1] 2,2-Dimethoxy-2-phenylacetophenone, (η6-cumene)(η5-cyclopentadienyl)ferric hexafluorophosphate, 2-hydroxy-2-methylphenylacetone, [4-(2-hydroxytetradecoxy)phenyl]phenyliodonium hexafluoroantimonate, 2-isopropylthioxanthone; [Group 2] 2-Methyl-4'-(methylthio)-2-morpholinophenylacetone, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyroylbenzene, diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide.

5. The display device according to claim 1, wherein, The display device has a hole that passes through the display module and the adhesive layer and overlaps with the non-curved area in a plane.

6. The display device according to claim 1, wherein, The third adhesive portion is formed by curing a third resin comprising the first photoinitiator and the second photoinitiator.

7. The display device according to claim 6, wherein, The third resin is a resin formed by the interdiffusion of the first resin and the second resin. In the third resin, the first photoinitiator and the second photoinitiator have a concentration gradient.

8. A method for manufacturing a display device, comprising: Provide steps for defining a display module with a first region and a second region; The step of coating the first region of the display module with a first resin comprising a first initiator; The step of coating the second region of the display module with a second resin comprising a second initiator different from the first initiator; The step of forming a third resin between the first resin and the second resin; The step of curing the first resin to achieve a curing rate of 50% or more and 80% or less, thereby forming a first pre-adhesive layer; The step of aligning the window portion with the defined curved and non-curved regions with the display module; as well as The step of bonding the display module and the window. The third resin includes the first initiator and the second initiator.

9. The method for manufacturing a display device according to claim 8, further comprising: The step of curing the second resin to achieve a curing rate of 10% or more and 40% or less, thereby forming a second pre-adhesive layer.

10. The method of manufacturing a display device according to claim 8, wherein, Following the step of bonding the display module and the window, the method further includes a formal curing step in which the first pre-adhesive layer and the second resin are cured to achieve a curing rate of 90% or more and 100% or less.

Images