Display device

Abstract

A display device includes: a display area on a substrate, the display area including a plurality of pixels; a non-display area on the substrate located outside the display area, the non-display area including a display driver; and a bending area between the display area and the non-display area. The substrate may include: a first glass substrate in the display area; a second glass substrate in the non-display area; and a third glass substrate in the bending region and having a pattern.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority and benefit of Korean Patent Application No. 10 - 2023 - 0197375, filed on December 29, 2023, the entire disclosure of which is incorporated herein by reference. Technical field

[0003] The present invention relates to a display device. Background art

[0004] Display devices are applied to various electronic devices, such as TVs, mobile phones, laptop computers, and tablet computers. Therefore, continuous research is being conducted to develop smaller, thinner, lighter, and low - power - consuming display devices.

[0005] Among these display devices, liquid crystal display devices, self - emissive display devices, and electrophoretic display devices can be configured to be thinner.

[0006] Recently, among these display devices, miniaturization of mobile communication terminals such as smart phones and tablet PCs is being pursued. In addition, research and development are being carried out to maximize the display screen area in a display device of the same size by implementing narrow bezels and reducing the bezel area where no image is displayed. Summary of the invention

[0007] The present invention aims to provide a display device that substantially solves one or more problems caused by the limitations and disadvantages of the related art.

[0008] The present invention aims to provide a display device in which a display - area substrate, a bending - area substrate, and a non - display - area substrate can be manufactured on a mother glass substrate without performing any additional processing or under the condition of performing a reduced amount of additional processing.

[0009] The present invention also aims to provide a display device in which the reliability of the bending area can be improved, the size of the bending area can be reduced, and thus the width of the bezel area can be minimized or reduced.

[0010] The object of the present invention is not limited to the above objects, and other objects will be clearly understood by those of ordinary skill in the art from the following description.

[0011] To achieve these objects and other advantages of the present invention, as embodied and broadly described herein, a display device may include: a display area on a substrate, the display area including a plurality of pixels; a non-display area on the substrate outside the display area, the non-display area including a display driver; and a bending area between the display area and the non-display area. The substrate may include: a first glass substrate in the display area; a second glass substrate in the non-display area; and a third glass substrate in the bending area and having a pattern.

[0012] In another aspect of the present invention, a display device may include: a first substrate including a plurality of pixels configured to display an image; a second substrate spaced apart from the first substrate and including display pads electrically connected to at least one pixel; and a third substrate between the first substrate and the second substrate, the third substrate being formed with a pattern and bent. The third substrate may have a smaller thickness than each of the first substrate and the second substrate.

[0013] Additional features and aspects of the present invention will be set forth in the following description, will become apparent in part from the description, or may be learned by practice of the inventive concepts provided herein. Other features and aspects of the inventive concepts may be realized and obtained by means of the structures specifically pointed out or derivable in the written description and claims thereof and the drawings.

[0014] It will be understood that the foregoing general description and the following detailed description of the present invention are both exemplary and are intended to provide further explanation of the claimed invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which provide a further understanding of the present invention and constitute a part of this application, illustrate exemplary embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. In the drawings:

[0016] Figure 1 is a block diagram of a display panel and a driving unit of a display device according to an exemplary embodiment of the present invention;

[0017] Figure 2 is a schematic perspective view of a glass substrate for describing the bending direction of the glass substrate according to an exemplary embodiment of the present invention;

[0018] Figure 3A is a plan view of a glass substrate according to an exemplary embodiment of the present invention;

[0019] Figure 3B is a plan view of a glass substrate according to another exemplary embodiment of the present invention;

[0020] Figure 4A and 4B is a view illustrating an exemplary pattern according to an exemplary embodiment of the present invention;

[0021] Figures 5A to 5F is along Figure 1 Exemplary cross-sectional view taken along line I-I' of, illustrating a method of manufacturing a glass substrate of a display device according to an exemplary embodiment of the present invention;

[0022] Figure 6A is a cross-sectional view of a display device in a bent or folded state according to an exemplary embodiment of the present invention;

[0023] Figure 6B is Figure 6A An enlarged cross-sectional view of region B in;

[0024] Figure 6C is an enlarged view of a bending region according to another exemplary embodiment of the present invention;

[0025] Figures 7A to 7F is along Figure 1 Exemplary cross-sectional view taken along line II-II' of, illustrating examples of one or more bending lines provided in a third glass substrate and an etch stop layer in a bending region of a display device according to an exemplary embodiment of the present invention;

[0026] Figure 8 is an enlarged view of a bending region according to yet another exemplary embodiment of the present invention. Detailed Description of the Invention

[0027] Reference will now be made in detail to various embodiments of the present invention, some examples of which are illustrated in the accompanying drawings.

[0028] The advantages and features of the present invention and the methods for realizing them will be clear from the following exemplary embodiments described with reference to the accompanying drawings. However, the present invention can be implemented in different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that the disclosure of the present invention will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0029] In the following description, if a detailed description of related known functions or configurations may unnecessarily obscure various aspects of the present invention, the detailed description of such known functions or configurations may be omitted.

[0030] The shapes, sizes, ratios, angles, numbers, etc. shown in the accompanying drawings for describing various exemplary embodiments of the present invention are given by way of example only. Therefore, the present invention is not limited to the illustrations in the accompanying drawings.

[0031] Like reference numerals refer to like elements throughout, unless otherwise indicated. The names of the corresponding elements adopted in the following description are chosen for convenience of description and thus may be different from those used in actual products.

[0032] Terms such as "comprising", "having", "including", "consisting of", "containing" used herein are generally intended to allow the inclusion or addition of one or more other elements, unless these terms are used together with more restrictive terms such as "only". As used herein, the singular forms are intended to include the plural forms unless the context clearly indicates otherwise.

[0033] Although terms such as "first", "second", A, B, (a), (b), etc. may be used herein to describe various elements, these elements should not be construed as being limited by these terms, as they are not used to define a particular order, sequence, priority or number of these elements. These terms are only used to distinguish one element from other elements. For example, without departing from the scope of the present invention, the first element may be referred to as the second element, and the second element may similarly be referred to as the first element.

[0034] When expressions such as an element or layer being "connected to", "joined to", "adhered to" another element or layer or "overlapping" with another element or layer are used, the element or layer may not only be directly connected to, joined to or adhered to another element or layer or directly in contact with or overlapping another element or layer, but may also be indirectly connected to, joined to or adhered to another element or layer or indirectly overlap with another element or layer on the condition that one or more intermediate elements or layers are "disposed" or "interposed" between the elements or layers, unless otherwise indicated.

[0035] When describing positional relationships, for example, when using descriptions such as "on", "above", "below", "upper", "lower", "beside", "after", etc. to describe the positional relationship between two parts, one or more other parts may be located between the two parts, unless more restrictive terms such as "immediately", "directly" or "adjacent" are used. For example, when an element or layer is described as being disposed on another element or layer, a third element or layer may be inserted therebetween.

[0036] In addition, when discussing any dimensions, relative dimensions, etc., the numerical values or corresponding information (such as levels, ranges, etc.) of elements or features should be considered to include ranges of tolerances or errors that may be caused by various factors (such as process factors, internal or external collisions, noise, etc.), even if no clear description of such ranges of tolerances or errors is provided. In addition, the term "may" fully encompasses the entire meaning of the term "can".

[0037] Figure 1It is a block diagram showing a display panel and a driving unit of a display device according to an exemplary embodiment of the present invention.

[0038] As Figure 1 shown, the display device 1000 according to an exemplary embodiment of the present invention may include: a display area DA provided on a first glass substrate (or first substrate) 110; and a non-display area NDA surrounding the display area DA. The display area DA is an area configured to display an image and may be supported by the first glass substrate 110. The display area DA may include a plurality of pixels. The plurality of pixels may be arranged in a matrix form, and each of the plurality of pixels may include sub-pixels. The display area DA may have a substantially rectangular shape. However, embodiments of the present invention are not limited thereto, and the display area DA may have any of various other shapes such as various polygons. For example, according to the shape of the display device, the display area may have a triangular, pentagonal, or hexagonal shape. In the present application, for ease of description, hereinafter, an exemplary display area DA having a rectangular shape will be described based on an exemplary display device 1000 having a rectangular shape.

[0039] The non-display area NDA may be an area surrounding the display area DA and may include elements and circuit lines for driving elements and / or circuits such as pixel elements and / or circuits located in the display area DA.

[0040] The bending area BA may be provided on the first glass substrate 110 at one side or one end of the non-display area NDA. The bending area BA may be provided between the display area DA and the non-display area NDA. The bending area BA may be defined as an area formed in such a way that a part of the non-display area NDA of the display device 1000 is bent. Therefore, the display device according to an exemplary embodiment of the present invention may be folded or bent to have a constant radius of curvature according to the degree of folding of the bending area BA.

[0041] The area provided at one side or one end of the bending area BA of the non-display area NDA may be defined as a display pad portion. The display pad portion may be formed on a second glass substrate (or second substrate) 120 and may be attached to the rear surface of the first glass substrate 110 using an adhesive or the like. The first glass substrate 110 may be provided in the display area DA. The second glass substrate 120 may be provided in the non-display area NDA. In the display pad portion, lines, pads, etc. provided for driving the display panel of the display device 1000, such as the display pad 720, etc., may be provided.

[0042] In the non-display area NDA formed on the first glass substrate 110 at one side or multiple sides of the display area DA where the bending area is not provided, one or more driving circuits for driving elements in the display area DA, such as the gate driving circuit 800, and circuit lines S / L connected between the driving circuit and the elements in the display area DA may be provided.

[0043] The pixel array layer, the protective layer, and the touch sensor layer may be sequentially formed on the upper surface of the first glass substrate 110. Then, the glass substrate 100 (for example, see Figures 5A to 5F ) may undergo a thinning process. In this case, the first glass substrate 110 and the second glass substrate 120 may be formed from corresponding portions of the glass substrate 100 and may each have a first thickness.

[0044] The third glass substrate (or the third substrate) 130 may be disposed in the bending region BA and may be bendable. Thus, considering the stress during bending, one or more patterns PTN (see Figure 3A and 3B ) may be configured in the third glass substrate 130 disposed in the bending region BA, and the third glass substrate 130 may have a second thickness less than the first thickness of each of the first glass substrate 110 and the second glass substrate 120. The thickness difference between the glass substrates will be described in more detail below.

[0045] Figure 2 is a schematic perspective view of the glass substrate 100 (including the first glass substrate 110, the second glass substrate 120, and the third glass substrate 130) for describing the bending direction of the glass substrate 100 according to an exemplary embodiment of the present invention.

[0046] In Figure 2 , for ease of description, the non-display area NDA disposed at the periphery of the display area DA of the first glass substrate 110 is omitted. However, a portion of the non-display area NDA in which the gate driving circuit 800 and the like are disposed may be formed on the first glass substrate 110 at the periphery of the display area DA where the bending region BA is not provided.

[0047] As Figure 2 shown, the bending region BA of the glass substrate 100 may be bent in the bending direction BD. For example, the bending of the bending region BA of the glass substrate 100 may mean that in the bending region BA of the glass substrate 100 located on the XY plane, one side of the glass substrate 100 in the positive direction of the X axis gradually bends from the positive direction of the X axis via the negative direction of the Z axis towards the negative direction of the X axis. In addition, as Figure 2 shown, the bending direction BD of the bending region BA indicates: the direction perpendicular to the boundary between the display area DA and the bending region BA (for example, the dotted line between the display area DA and the bending region BA in Figure 2 ). That is, the bending direction BD of the bending region BA indicates the positive direction of the Z axis, which is the direction among the directions perpendicular to the YZ plane where the boundary between the display area DA and the bending region BA is located and towards the bending region BA from the boundary between the display area DA and the bending region BA.

[0048] Figure 3AAnd 3B is a plan view of a glass substrate according to an exemplary embodiment of the present invention.

[0049] As Figure 3A shown, the glass substrate 100 may include: (1) a first glass substrate 110 on which a display area DA is provided; (2) a second glass substrate 120 that may overlap with a display pad portion (where a driving circuit and a display pad 720 may be provided) in a non-display area NDA, and may be attached to the rear surface of the first glass substrate 110 using an adhesive or the like; and (3) a third glass substrate 130 disposed in a bending area BA between the first glass substrate 110 and the second glass substrate 120.

[0050] An area of the second glass substrate 120 that does not overlap with the bending area BA of the non-display area NDA and is attached to the rear surface of the first glass substrate 110 using an adhesive or the like may be defined as a rear flat area RFA. The rear flat area RFA may be smaller than the display area DA.

[0051] One or more patterns PTN may be formed on the third glass substrate 130. At least some of the patterns PTN of the third glass substrate 130 may extend in a diagonal direction with respect to the boundary between the display area DA and the bending area BA and with respect to the bending direction BD of the bending area BA. Therefore, as the bending area BA of the glass substrate 100 bends, the stress received by the third glass substrate on which a plurality of patterns PTN are provided above may be reduced, thereby minimizing or reducing the occurrence of cracks in the third glass substrate 130. Accordingly, the occurrence of cracks in the bending line 614 formed in the etch stop layer 610 (for example, see Figures 5A to 5F ) above the third glass substrate 130 may be prevented or reduced.

[0052] Figure 3B is a plan view of a glass substrate according to another exemplary embodiment of the present invention.

[0053] As Figure 3B shown, in order to reduce the stress received by the glass substrate and the stress during bending, a coating layer such as a microcoating layer 622 may be provided between the first glass substrate 110 and the third glass substrate 130 and between the second glass substrate 120 and the third glass substrate 130.

[0054] Since cracks may occur in the microcoating layer 622 due to the tension during bending, the microcoating layer 622 may be used to protect the lines and the substrate by forming a thin layer made of a material such as resin at the bending position. The microcoating layer 622 may be made of an acrylic material such as acrylate polymer, but is not limited thereto. In Figure 3BIn [the figure], the microcoating layer 622 is illustrated as being disposed only between the first glass substrate 110 and the third glass substrate 130 and between the second glass substrate 120 and the third glass substrate 130, but the present invention is not limited thereto. For example, the microcoating layer 622 may fill all the blank spaces of the fine pattern PTN of the third glass substrate 130 or may be disposed to cover the entire third glass substrate.

[0055] Figure 4A and 4B is a view illustrating a pattern according to an exemplary embodiment of the present invention.

[0056] As Figure 4A shown, one or more patterns PTN may extend in directions D1 and D2 different from the bending direction BD of the bending region BA. By forming the pattern PTN of the third glass substrate 130 to extend in a direction different from the bending direction BD, the stress received by the third glass substrate can be reduced. In addition, since the pattern PTN extends in a direction different from the bending direction BD, blank spaces EMT may be formed between the patterns PTN. Due to the pattern PTN configured in this way, the stress received by the third glass substrate 130 during bending can be reduced, and as the stress is reduced, the occurrence of cracks in the third glass substrate 130 during bending can also be reduced.

[0057] As Figure 4B shown, in addition to the first pattern PTN1 ( Figure 4A PTN shown), the pattern PTN in the exemplary embodiment of the present invention may further include various types of second to fifth patterns PTN2, PTN3, PTN4, PTN5. For example, the pattern according to an exemplary embodiment of the present invention may include: (1) a grid or mesh-like pattern PTN2 formed by extending in the same direction D3 as the bending direction BD and in a direction D4 perpendicular to the bending direction BD of the bending region BA; (2) striped patterns PTN3 and PTN4 extending in the same straight direction D3 as the bending direction DB or in the perpendicular direction D4; and (3) a zig-zag-like pattern PTN5 extending in a direction different from the bending direction BD in the same direction as the first pattern PTN1 or extending in a direction obliquely intersecting the bending direction BD. However, the length of the pattern extending in the first direction D1 is different from the length of the pattern extending in the second direction D2. The present invention is not limited to these exemplary patterns PTN, and any other various patterns capable of dispersing stress during bending may also be employed.

[0058] Figures 5A to 5F is a view illustrating a method of manufacturing a glass substrate of a display device according to an exemplary embodiment of the present invention.

[0059] As Figure 5AAs shown, the display device 1000 may include: a glass substrate 100; a pixel array layer 210; a display pad portion 220; an etch stop layer 610; a first microcoating layer 621; a polarization layer 300; a first adhesive layer 400; and a cover glass 500.

[0060] The pixel array layer 210 may be disposed in the display area DA on the glass substrate 100. The pixel array layer 210 may be disposed in a pixel area defined by pixel driving lines (not shown) disposed on the display area DA, and may include a plurality of pixels configured to display an image according to signals provided to the pixel driving lines. Here, the pixel driving lines may include, for example, data lines, gate lines, and pixel driving power supply lines. Each of the plurality of pixels may include, for example, a pixel circuit layer, an anode electrode layer, a self-emitting element layer, and a cathode electrode layer.

[0061] The pixel array layer 210 may be disposed in the transistor area of each pixel area, and may be driven according to signals provided from adjacent pixel driving lines to control the light emission of the self-emitting element layer. The pixel array layer 210 may include, for example, at least two thin film transistors (including a driving thin film transistor) and at least one capacitor disposed in the transistor area defined in each pixel area of the first glass substrate 110. Here, the pixel circuit layer may include at least one type of TFT among amorphous silicon (a-Si) TFT, polycrystalline silicon (poly-Si) TFT, oxide TFT, and organic TFT.

[0062] The anode electrode layer may be electrically connected to the driving thin film transistor. The self-emitting element layer may be formed on the anode electrode layer disposed in the opening area of each pixel. Here, the opening area of each pixel area may be defined by a bank pattern formed on a coating layer to cover the edge of the anode electrode layer.

[0063] The self-emitting element layer may include, for example, an organic light emitting element, a quantum dot light emitting element, or an inorganic light emitting element. For example, the self-emitting element layer may be formed in a structure in which a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer are sequentially stacked. Here, one or more of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer may be omitted. The organic light emitting layer may be formed to emit the same color of light, such as white light, for each pixel; or may be formed to emit different colors of light, such as red light, green light, blue light, or white light, for each pixel.

[0064] The polarization layer 300, the first adhesive layer 400, and the cover glass 500 sequentially disposed on the pixel array layer 210 may be included in the display device 1000.

[0065] The polarization layer 300 may include a linear polarizer and a phase retardation film. The polarization layer 300 may improve outdoor visibility by preventing light incident from the outside of the display device 1000 from being reflected by the metal layer inside the display device 1000 and emitted.

[0066] External unpolarized light may pass through the linear polarizer having a light transmission axis of 90°. Only the transmitted linearly polarized light having the same light transmission axis as the linear polarizer passes through the phase retardation film, becomes circularly polarized at 135°, and can be incident on (or reflected by) the electrodes or TFTs inside the display device. The reflected circularly polarized light may pass through the phase retardation film again and may become linearly polarized light that is totally retarded by 180°. All the linearly polarized light retarded by 180 degrees may be absorbed by the linear polarizer having a light transmission axis of 90°, thereby preventing light incident from the outside of the display device 1000 from being reflected by the internal metal layer of the display device 1000 and emitted from the internal metal layer of the display device 1000. The configuration of the polarization layer is not limited to the above example, and any other structure of the polarization layer that improves outdoor visibility may be employed.

[0067] The first adhesive layer 400 may include a pressure-sensitive adhesive, a foam-type adhesive, a liquid adhesive, a light-curable adhesive, or one or more other suitable adhesive materials. In some embodiments, the first adhesive layer 400 may be formed of a compressible material or may include a compressible material and may serve as a buffer material for the portion adhered by the first adhesive layer 400. As an example, the constituent material of the first adhesive layer 400 may be compressible. The first adhesive layer 400 may be formed in a multi-layer structure, and the multi-layer structure may include a buffer layer disposed between an upper layer and a lower layer of the adhesive material layer.

[0068] The cover glass 500 may be disposed to cover the entire upper surface (or front viewing surface) and the bending region BA of the display device 1000 and may be used to protect the display device 1000 from the impact of external collisions. The cover glass 500 may be made of, for example, a transparent plastic material, a glass material, or a tempered glass material.

[0069] The etch stop layer 610 may be disposed above the position where the glass substrate 100 is etched.

[0070] The etch stop layer 610 may be disposed between the display pad portion 220 and the pixel array layer 210. In order to prevent the etchant solution from penetrating into or through the substrate 100 when etching the substrate 100, the etch stop layer 610 may be disposed in a part of the display area DA, near the part where the glass substrate 100 is separated into the first glass substrate 110 and the third glass substrate 130, and the etch stop layer 610 may extend to cover the bending area BA in which the third glass substrate 130 is disposed. Accordingly, the etch stop layer 610 may be formed to further extend to cover a part of the rear flat area RFA, in the part where the glass substrate 100 is separated into the second glass substrate 120 and the third glass substrate 130.

[0071] The etch stop layer 610 may be formed of multiple layers. The etch stop layer 610 may include, for example, a first planarization layer 611, a second planarization layer 612 disposed on the first planarization layer 611, and a bank layer (not shown) disposed on the second planarization layer 612. For example, the etch stop layer 610 may be formed using various organic / inorganic films used in the pixel array layer 210 when forming the planarization layer and the bank layer. In addition, the etch stop layer 610 may be formed using a metal layer for forming a layer in the pixel array layer 210.

[0072] The signal line S / L disposed at the pixel array layer 210 may extend to the bending area BA and may be electrically connected to a plurality of data pad electrodes disposed on the display pad portion 220. The etch stop layer 610 may be disposed on the substrate in the bending area BA. The signal line S / L disposed and bent in the bending area BA may be defined as a bent line 614.

[0073] The bent line 614 may be formed inside the etch stop layer 610. The bent line 614 may be additionally formed with a pattern PTN to reduce the tension during bending, and a buffer layer formed with the pattern PTN may be additionally disposed under the bent line 614.

[0074] The first microcoating layer 621 may be disposed on the etch stop layer 610 and the bent line 614. Due to the tension applied during bending, cracks may occur in the bent line 614. Accordingly, the first microcoating layer 621 may be formed to have a smaller thickness at the position where the resin is bent, and may be used to protect the bent line 614 (or the signal line S / L). The first microcoating layer 621 may be made of an acrylic material such as acrylate polymer, but is not limited thereto. One or more of various resins may be applied without limitation.

[0075] The first microcoating layer 621 can control the neutral plane NS of the bending region BA. The neutral plane NS can be a virtual plane where the structure does not receive stress when the structure is bent because the pressure and tension applied to the structure cancel each other out. When stacking two or more structures, the virtual neutral plane NS can be formed between the structures.

[0076] When the entire structure is bent in one direction, the structure disposed in the bending direction based on the neutral plane NS can be compressed by bending, thereby receiving pressure. Conversely, the structure disposed in the direction opposite to the bending direction based on the neutral plane NS can be stretched by bending, thereby receiving tension. In addition, the structure is more vulnerable when subjected to tension than when subjected to pressure of the same intensity. Therefore, when subjected to tension, the possibility of cracks occurring is higher.

[0077] Based on the neutral plane NS, the underlying glass substrate 100 can be compressed, thereby receiving pressure; the etch stop layer 610 disposed above can receive tension. Therefore, due to this tension, cracks can occur. Therefore, in order to minimize or reduce the tension received by the bending line 614, the first microcoating layer 621 can be disposed on the etch stop layer 610 in the bending region BA.

[0078] By disposing the first microcoating layer 621 in the bending region BA, the neutral plane NS can be lifted upward. The neutral plane NS can be configured to be in the same vertical position as the bending line 614 or in a higher vertical position than the bending line 614. Therefore, the bending line 614 is subjected to pressure rather than tension during bending, thus being less susceptible to stress, thereby suppressing the occurrence of cracks in the bending line 614.

[0079] The etch stop layer 610 can be disposed between the display pad portion 220 and the pixel array layer 210.

[0080] The etch stop layer 610 can include, for example: a plurality of data pad electrodes disposed in the display pad portion 220; a plurality of data connection lines connected to signal lines disposed in the pixel array layer 210; a plurality of gate pad electrodes disposed on the display pad portion 220; and a plurality of gate connection lines connected to the driving circuit. The bending line 614 can include one or more of the data connection lines and the gate connection lines. Optionally, the bending line 614 can be an extension of a signal line in the pixel array layer 210.

[0081] As Figure 5BAs shown, a process of etching a glass substrate 100 can be performed using a mask MASK. The mask can include at least two holes H1 and H2 to separate the glass substrate 100 into a first glass substrate 110, a second glass substrate 120, and a third glass substrate 130. The mask can additionally include one or more micro-pattern holes mPTN to form a pattern PTN of the third glass substrate 130 disposed in the bending area BA. In this case, the mask can be patterned using a laser cutting or gear cutting process.

[0082] Next, the set mask can be used to etch the glass substrate 100, as Figure 5B and 5C shown, and the glass substrate 100 can be separated into a first glass substrate 110, a second glass substrate 120, and a third glass substrate 130 disposed to overlap the bending area BA of the display device. Here, the glass etching process can be performed as a wet etching process rather than a dry etching process. In the process of etching the glass substrate 100, the etched surface of the first glass substrate 110 or the second glass substrate 120 can be configured to be tapered. In the third glass substrate 130, the pattern PTN can be formed through the micro-pattern holes mPTN of the mask.

[0083] The etching process can be performed simultaneously with the glass substrate thinning process. After performing the thinning process, the thickness range of the glass substrate 100 can be from 0.05 mm to 0.2 mm. However, the thickness of the glass substrate is not limited to this range, and any thickness of the glass substrate 100 applied to the display device in the art can be used without limitation.

[0084] As Figure 5D and 5E shown, the third glass substrate 130 can be further etched to reduce the stress during bending of the third glass substrate 130. Finally, the thickness T2 of the third glass substrate can be less than the thickness T1 of each of the first glass substrate 110 and the second glass substrate 120.

[0085] A second microcoating layer 622 can be additionally coated onto the etched blank spaces between the first glass substrate 110 and the third glass substrate 130 and between the second glass substrate 120 and the third glass substrate 130. By coating the second microcoating layer 622, the stress applied to the third glass substrate 130 and the etching stop layer 610 in the bending area BA during bending can be reduced. The second microcoating layer 622 can be made of the same or similar material as the first microcoating layer 621.

[0086] As Figure 5FAs shown, the second adhesive layer 101 may be disposed below one or both of the first glass substrate 110 and the second glass substrate 120 such that the second glass substrate 120 can adhere to the rear surface of the first glass substrate 110 when bent or folded. When the second glass substrate 120 is adhered and disposed on the rear surface of the first glass substrate 110, the area (e.g., the lateral area) of the non-display area NDA can be reduced to achieve a narrow bezel, thereby reducing the unnecessary space of the display device 1000.

[0087] The flexible circuit film 710 may be disposed on the display pad portion 220. The display driver 700 may be mounted on the flexible circuit film 710 through a chip bonding process or a surface mounting process. The display driver 700 may generate a data signal and a gate control signal based on image data and a timing synchronization signal provided from an external display driving system, and may supply the data signal to the data lines of each pixel and supply the gate control signal to the driving circuit.

[0088] Optionally, instead of being mounted on the flexible circuit film 710, the display driver 700 may be directly mounted on the display pad portion 220 provided on the second glass substrate 120 and electrically connected to the display pad portion 220 provided on the second glass substrate 120, and may be electrically connected to each of the gate driving circuit and the pixel driving signal lines provided in the pixel array layer 210. In this case, the flexible circuit film 710 may be used to relay the signal transmission between the pad portion and the external display driving system.

[0089] The source printed circuit board (S-PCB) 900 may be disposed on one side of the flexible printed circuit board 710.

[0090] The data driver configured to drive the display device 1000 may be mounted on the S-PCB 900.

[0091] Figure 6A is a cross-sectional view of a display device according to an exemplary embodiment of the present invention.

[0092] Since, except for the structure or configuration of the bending area BA, Figure 6A the display device shown is Figure 5F the same as or similar to the display device shown, a repeated description is omitted.

[0093] As Figure 6A shown, the third glass substrate 130 and the etch stop layer 610 provided in the bending area BA can be bent.

[0094] The etching stop layer 610 may cover each of the following: (1) the upper portion of one side 110B of the first glass substrate 110 provided with the etched surface 110A of the first glass substrate 110; (2) the third glass substrate 130 in the bending region BA; and (3) the upper portion (or the lower portion in the bent or folded state) of one side 120B of the second glass substrate 120 provided with the etched surface 120A of the second glass substrate 120.

[0095] To disperse the stress during the bending of the third glass substrate 130 and the etching stop layer 610, the first microcoating layer 621 and the second microcoating layer 622 may be provided on the upper portion of the etching stop layer 610 and at the left and right sides (or both ends) of the third glass substrate 130, respectively. The first microcoating layer 621 covering the etching stop layer 610 may be provided in the bending region BA from the upper portion of one side 110B of the first glass substrate 110 provided with the etched surface 110A to the upper portion of one side 120B of the second glass substrate 120 provided with the etched surface 120A (or the lower portion in the bent or folded state). The second microcoating layer 622 may be coated to fill the regions below the etching stop layer 610 between the tapered etched surface 110A of the first glass substrate 110 and one side of the third glass substrate 130 and between the other side of the third glass substrate 130 and the tapered etched surface 120A of the second glass substrate 120.

[0096] After bending or folding, the second glass substrate 120 provided with the display pad portion 220 thereon may be adhered to the rear surface of the first glass substrate 110 through the second adhesive layer 101 on the rear surface of the first glass substrate 110 to form the rear flat region RFA.

[0097] Since the second glass substrate 120 is adhered and disposed on the rear surface of the first glass substrate 110, the area (e.g., the lateral area) of the non-display region NDA may be reduced to achieve a narrow border, thereby reducing the front surface of the display device 1000 that is not used for displaying images.

[0098] Figure 6B is taken as Figure 6A an enlarged cross-sectional view of a part of the bending region that is the B region in Figure 6C is an enlarged view of a part of the bending region according to another embodiment of the present invention.

[0099] As Figure 6B and 6CAs shown, each of the etched surfaces 110A of the first glass substrate 110 and 120A of the second glass substrate 120 is configured to be tapered. By bending the third glass substrate 130 disposed in the bending region BA, the second glass substrate 120 can be disposed in the rear flat region RFA, and the etched surfaces 110A of the first glass substrate 110 and 120A of the second glass substrate 120 can be disposed at opposite angles or a diverging angle.

[0100] Due to the pressure during bending, the second adhesive layer 101 may protrude or extend into the bending region, thereby forming a protrusion 101A. The outermost side 101B of the protrusion 101A may contact the bent third glass substrate 130.

[0101] In addition, as Figure 6C shown, the outermost side 101B of the protrusion 101A of the second adhesive layer 101 may be filled between the patterns PTN of the third glass substrate or fill the space in the pattern PTN, and may contact the lower surface of the etch stop layer 610.

[0102] Figures 7A to 7F is a cross-sectional view illustrating each example of the third glass substrate 130 and one or more bending lines 614 of the connection line portion disposed in the bending region of the display device according to an exemplary embodiment of the present invention. Figure 8 is an enlarged view of a bending region according to another exemplary embodiment of the present invention.

[0103] Figure 7A is a schematic cross-sectional view showing the etch stop layer 610 disposed in the bending region BA. The first microcoating layer 621 and the second microcoating layer 622 are omitted for ease of description. The etch stop layer 610 may include a first planarization layer 611, a second planarization layer 612 disposed on the first planarization layer 611, and a dam layer 613 disposed on the second planarization layer 612. In another example, the dam layer may be disposed on the etch stop layer, and the coating layer may be disposed on the dam layer. The third glass substrate 130 having the pattern PTN may be disposed below the first planarization layer 611. At least one of the first planarization layer 611 and the second planarization layer 612 may cover a part of the first glass substrate 110 and the second glass substrate 120.

[0104] The second planarization layer 612 of the etch stop layer 610 may include a bent line 614 connected to the data line of the gate drive circuit or the pixel. The bent line 614 may include a plurality of conductive metal layers. The bent line (or wire) 614 may be disposed between the first planarization layer 611 and the second planarization layer 612, and may be electrically connected to at least one of the display driver or the display pad and a plurality of pixels. The bent line (or wire) 614 may be bent together with the third glass substrate 130. The bent line 614 may include a plurality of metal layers such as Ti / Al / Ti. The bent line 614 may be formed in a region corresponding to the bending area BA, and the pattern PTN may be arranged to disperse the stress that may occur during the bending or folding of the bending area BA. The bent line 614 may be formed to have the same or matching or corresponding pattern as the pattern PTN of the third glass substrate 130.

[0105] Here, the same (or matching or corresponding) pattern means that if the pattern PTN of the third glass substrate 130 and the pattern of the bent line 614 are folded along the imaginary line between them, the patterns will completely or substantially overlap. This is shown, for example, in Figure 7A , 7C and 7E.

[0106] A buffer layer BUF may be disposed under the patterned bent line 614 to disperse the stress generated during bending. The buffer layer BUF may be formed of one or more layers of SiN x layer and SiO2 layer. In one exemplary configuration, the buffer layer BUF may be formed of an alternating stack of SiN x layer and SiO2 layer.

[0107] Preferably, in some applications, the pattern of the bent line 614 is made to match the pattern of the third glass substrate 130, such as shown in Figure 7A , 7C and 7E. However, as shown in Figure 7B , 7D and 7F, the pattern of the bent line 614 may be different or not match the pattern of the third glass substrate 130.

[0108] As shown in Figure 7C and 7D , by additionally stacking a metal as the second buffer layer BUF2 on the upper and lower portions of the bent line 614 to reduce the stress during bending, the bent line 614 of the etch stop layer 610 may include a MoTi / Al / MoTi bent line.

[0109] As shown in Figure 7E and 7FAs shown, the bent line 614 in the etch stop layer 610 may include a first buffer layer BUF located on the lower part of the Mo / Ti / Al / Mo / Ti bent line 614 (wherein a metal such as Mo is additionally stacked on the upper and lower parts of the bent line 614) to reduce the stress during bending. The constituent layers and constituent materials of the bent line are not limited thereto, and a single layer such as Al, Cu, etc.; a multi-layer line such as MoTi / Al / MoTi, Ti / Cu / Ti, etc.; or one or more metal layers having sufficient elongation and resistivity for signal lines of a display device such as an OLED display may be used.

[0110] Since, in addition to the structure of the bending area BA, Figure 8 the etch stop layer 610 shown (e.g., including a first planarization layer 611 and a second planarization layer 612) is the same as or similar to Figures 6A to 6C (or Figures 5A to 5F or Figures 7A to 7F ) the etch stop layer 610 shown, a repeated description thereof is omitted.

[0111] As Figure 8 shown, the thickness of the third glass substrate 130 provided in the bending area BA may be maximum at the center of the bending area BA (which will be located on the outermost side after bending). The third glass substrate 130 may have a greater thickness at the center part than at the peripheral part. The part of the third glass substrate 130 adjacent to the first glass substrate 110 and the second glass substrate 120 (or the inside of the third glass substrate 130 after bending) may be additionally etched to be thinner or completely removed. The second microcoating layer 622 may be coated to fill the space formed by etching the third glass substrate 130.

[0112] Each exemplary embodiment of the present invention may be described as follows.

[0113] A display device according to one or more exemplary embodiments may include: a substrate; a display area on the substrate, the display area including a plurality of pixels; a non-display area on the substrate outside the display area, the non-display area including a display driver; and a bending area between the display area and the non-display area. The substrate may include: a first glass substrate in the display area; a second glass substrate in the non-display area; and a third glass substrate in the bending area and having a pattern.

[0114] In some exemplary embodiments, the pattern may include a grid or zigzag shape.

[0115] In some exemplary embodiments, the display device may further include an etch stop layer provided on the first glass substrate, the second glass substrate, and the third glass substrate.

[0116] In some exemplary embodiments, the etch stop layer may include: a first planarization layer on the third glass substrate; and a second planarization layer on the first planarization layer. The display device may further include a bending line disposed between the first planarization layer and the second planarization layer, the bending line being electrically connected to at least one of the display driver and the plurality of pixels.

[0117] In some exemplary embodiments, the display device may further include a coating layer disposed between the third glass substrate and the first glass substrate and between the third glass substrate and the second glass substrate.

[0118] In some exemplary embodiments, the display device may further include a bank layer on the etch stop layer and a coating layer on the bank layer.

[0119] In some exemplary embodiments, the display device may further include at least one buffer layer disposed on or below the bending line.

[0120] In some exemplary embodiments, the bending line may be formed to have a pattern, and the pattern of the bending line may match the pattern of the third glass substrate.

[0121] In some exemplary embodiments, the thickness of the third glass substrate may be less than the thickness of each of the first glass substrate and the second glass substrate.

[0122] In some exemplary embodiments, the third glass substrate may have a greater thickness at the central portion than at the peripheral portion.

[0123] A display device according to one or more exemplary embodiments of the present invention may include: a first substrate including a plurality of pixels configured to display an image; a second substrate spaced apart from the first substrate and including display pads electrically connected to at least one pixel; and a third substrate between the first substrate and the second substrate, the third substrate being formed to have a pattern and being bent. The third substrate may have a smaller thickness than each of the first substrate and the second substrate.

[0124] In some exemplary embodiments, the pattern of the third substrate may have a grid or a sawtooth shape extending in a direction obliquely intersecting the bending direction of the third substrate.

[0125] In some exemplary embodiments, the display device may further include a wire located on the third substrate and electrically connected to the display pad and the at least one pixel, the wire being bent together with the third substrate.

[0126] In some exemplary embodiments, the wire may be formed to have a pattern, and the pattern of the wire may match the pattern of the third substrate.

[0127] In some exemplary embodiments, the display device may further include: a first planarization layer between the third substrate and the wire; a second planarization layer on the wire; and a coating layer on the second planarization layer.

[0128] In some exemplary embodiments, at least one of the first planarization layer and the second planarization layer may cover a part of the first substrate and the second substrate.

[0129] In some exemplary embodiments, the display device may further include an adhesive layer on the rear surface of the first substrate. The second substrate may be attached to the rear surface of the first substrate via the adhesive layer.

[0130] In some exemplary embodiments, the adhesive layer may contact the third substrate.

[0131] In some exemplary embodiments, the display device may further include an etch stop layer on the third substrate. The adhesive layer may fill the space in the pattern of the third substrate and contact the etch stop layer.

[0132] In some exemplary embodiments, the display device may further include a coating layer located in the space between the third substrate and the first substrate and in the space between the third substrate and the second substrate.

[0133] In some exemplary embodiments, the first substrate, the second substrate, and the third substrate may be glass substrates.

[0134] In some exemplary embodiments, the third substrate may have a greater thickness at the central portion than at the peripheral portion.

[0135] According to an embodiment of the present invention, a display device may be provided, which has a display area substrate, a bending area substrate, and a non-display area substrate, and the display area substrate, the bending area substrate, and the non-display area substrate may be formed by process optimization without performing any additional processing or under the condition of performing a reduced amount of additional processing. In addition, according to an embodiment of the present invention, a display device may be provided, which has improved reliability of the bending area and a reduced size of the bending area, and thus has a reduced width of the border area.

[0136] The advantages and effects according to the present invention are not limited to the above effects, and additional advantages and effects are included in the disclosure of the present invention or are understandable to those of ordinary skill in the art according to the disclosure of the present invention.

[0137] It will be apparent to those of ordinary skill in the art that the present invention is not limited by the above exemplary embodiments and the accompanying drawings, and various substitutions, modifications, and variations can be made to the present invention without departing from the spirit or scope of the present invention. Therefore, the above exemplary embodiments of the present invention are provided for illustrative purposes and are not intended to limit the scope and technical concept of the present invention. The protection scope of the present invention should be interpreted based on the appended claims and their equivalents, and the present invention is intended to cover all modifications and variations of the present invention that fall within the scope of the appended claims and their equivalents.

Claims

1. A display device, comprising: A display area on the substrate, the display area comprising a plurality of pixels; a non-display area on the substrate located outside the display area, the non-display area including a display driver; as well as a curved area between the display area and the non-display area, The substrate comprises: a first glass substrate in the display area; a second glass substrate in the non-display area; and A third glass substrate is in the bending region and has a pattern. The display device according to claim 1 , wherein the pattern comprises a grid or a sawtooth shape. 3 . The display device according to claim 1 , further comprising an etch stop layer disposed on the first glass substrate, the second glass substrate, and the third glass substrate.

4. The display device according to claim 3, wherein: The etching stop layer includes: a first planarization layer on the third glass substrate and a second planarization layer on the first planarization layer. The display device further includes a bending line disposed between the first planarization layer and the second planarization layer, the bending line being electrically connected to at least one of the display driver and the plurality of pixels.

5. The display device according to claim 4, further comprising: A coating layer is disposed between the third glass substrate and the first glass substrate and between the third glass substrate and the second glass substrate.

6. The display device according to claim 4, further comprising: a bank layer on the etch stop layer; as well as A coating layer is provided on the bank layer. 7 . The display device according to claim 4 , further comprising at least one buffer layer disposed on or under the bending line.

8. The display device according to claim 4, wherein: The bending line is formed to have a pattern, The pattern of the bending lines matches a pattern of the third glass substrate. 9 . The display device according to claim 1 , wherein a thickness of the third glass substrate is smaller than a thickness of each of the first glass substrate and the second glass substrate. 10 . The display device according to claim 1 , wherein the third glass substrate has a greater thickness at a central portion than at a peripheral portion.

11. A display device, comprising: a first substrate including a plurality of pixels configured to display an image; a second substrate spaced apart from the first substrate and comprising a display pad electrically connected to at least one pixel; as well as a third substrate between the first substrate and the second substrate, the third substrate being formed to have a pattern and being bent, The third substrate has a smaller thickness than each of the first substrate and the second substrate. 12 . The display device according to claim 11 , wherein the pattern of the third substrate has a grid or a sawtooth shape extending in a direction oblique to a bending direction of the third substrate.

13. The display device according to claim 11, further comprising: A conductive line is located on the third substrate and is electrically connected to the display pad and the at least one pixel, and the conductive line is bent together with the third substrate.

14. The display device according to claim 13, wherein: The conductive line is formed to have a pattern, The pattern of the conductive line matches the pattern of the third substrate.

15. The display device according to claim 13, further comprising: a first planarization layer between the third substrate and the conductive line; a second planarization layer on the conductive line; as well as a coating layer on the second planarization layer, At least one of the first planarization layer and the second planarization layer covers a portion of the first substrate and the second substrate.

16. The display device according to claim 11, further comprising: an adhesive layer located on the rear surface of the first substrate, The second substrate is attached to the rear surface of the first substrate via the adhesive layer. The display device of claim 16 , wherein the adhesive layer contacts the third substrate.

18. The display device according to claim 17, further comprising: an etch stop layer on the third substrate, wherein the adhesive layer fills a space in the pattern of the third substrate and contacts the etch stop layer.

19. The display device according to claim 11, further comprising: A coating layer is located in a space between the third substrate and the first substrate and in a space between the third substrate and the second substrate. 20 . The display device according to claim 11 , wherein the first substrate, the second substrate, and the third substrate are glass substrates.

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