Substrate for display

Abstract

A substrate for a display, one side or the other side of which is folded to face each other, has a first area defined as a folding area and a second area defined as an unfolding area, and has a plurality of first through-holes formed in the first area and a plurality of second through-holes formed in the second area, the second through-holes including a 2-1 opening area opening to one side and a 2-2 opening area opening to the other side, the size of the 2-1 opening area of at least one second through-hole being different from the size of the 2-2 opening area.

Description

[0001] This case is a divisional application, the parent application being the application filed on April 16, 2020, with a priority date of April 29, 2019, entitled "Substrate for Display", and application number 202080032564.7. Technical Field

[0002] The embodiments relate to a substrate for a display. Background Technology

[0003] Recently, there has been a growing demand for flexible display devices that can easily perform various applications and display images on large screens when carried.

[0004] This flexible display can be folded or partially bent when carried or stored, and can be displayed as an unfolded display when showing images. Therefore, the image display area can be increased, and the user can easily carry the display.

[0005] After a flexible display device is folded or bent, the process of unfolding the flexible display device again can be repeated.

[0006] That is, since flexible display devices are repeatedly folded and unfolded, the substrate of the flexible display device is required to have a certain strength and elasticity, and no cracks or deformations should appear in the substrate during the folding and unfolding process.

[0007] Meanwhile, the substrate used for the display in a flexible display device is typically a metal substrate. This metal substrate is processed during manufacturing through a rolling process, which creates irregular corrugations on the substrate's surface. These corrugations increase the surface roughness of the substrate, and during repeated folding and unfolding operations, curling may occur in a certain area of ​​the substrate.

[0008] In particular, when curling occurs in the folded area of ​​the substrate used for the display, the folded area is not flattened. Therefore, when the substrate is folded, folding defects such as cracks appear in the folded area, and there is a problem of reduced folding reliability of the flexible display device.

[0009] In addition, the substrate for the display in a flexible display device is typically a metal substrate. This metal substrate may have openings through it in the folded and unfolded portions to distribute stress and ensure uniformity according to the heat treatment process.

[0010] Such openings can distribute the stress generated in the metal substrate during folding and reduce the difference in thermal deformation between the folded and unfolded parts during heat treatment. However, other problems may occur due to dimensional deviations (e.g., the width of the opening's interior).

[0011] That is, since the width and diameter of the opening are formed differently depending on the position inside the opening, when the through hole is not formed in the center, deformations such as bending of the metal substrate may occur due to the stress difference acting on one surface and another surface of the metal substrate.

[0012] Therefore, there is a need for a new type of substrate for displays that can minimize ripples, curling, and bending in folded areas of the substrate used in flexible display devices. Summary of the Invention

[0013] Technical issues

[0014] The embodiments aim to provide a substrate for a display that has improved folding reliability by planarizing the folding area.

[0015] The embodiments aim to provide a substrate for a display that has improved folding reliability by reducing the dimensional deviation between the internal region of the hole and the through hole.

[0016] Technical solution

[0017] According to an embodiment, a substrate for a display includes: a surface and another surface opposite to the first surface; and a first region and a second region, wherein one surface or the other surface is folded to face each other, the first region is defined as a folded region, and the second region is defined as an unfolded region, a plurality of first through holes are formed in the first region, and a plurality of second through holes are formed in the second region, the second through holes including a second-1 opening region with an opening on one surface and a second-2 opening region with an opening on the other surface, and the size of the second-1 opening region of at least one second through hole formed in the second region is different from the size of the second-2 opening region.

[0018] Beneficial effects

[0019] According to an embodiment, the substrate for a display can be configured such that the substrate bends in the direction of one or more surfaces of the substrate in the entire or a portion of the unfolded region by forming different sizes of the opening regions in the unfolded region.

[0020] Therefore, since the unfolded regions bend and curl in the direction of one surface or the other of the substrate, the folded areas between the unfolded regions can be naturally flattened. That is, a force pressing on the unfolded regions is generated due to the stress difference in the unfolded regions, and the folded areas between the unfolded regions can be naturally flattened by this force generated in the second region.

[0021] Furthermore, the ripples formed in the folded area during the rolling process are also pushed into the unfolded area, thereby reducing the ripples in the folded area and improving the surface smoothness of the first region 1A. That is, by reducing the ripples in the folded area, the surface roughness of the folded area 1A can be made smaller than that of the unfolded area.

[0022] Therefore, the substrate for the display according to this embodiment can prevent the folded area from curling and improve surface flatness. Consequently, defects such as cracks in the folded area during the folding process can be reduced, thereby improving the reliability of the flexible display device.

[0023] Furthermore, the substrate for the display according to the embodiment minimizes the size difference between the second inner region and the second through hole in the unfolded area. Therefore, even if the through hole is not located at the center of the hole, the size difference between the second-1 inner region and the second-2 inner region can be minimized.

[0024] Therefore, by minimizing the dimensional difference between the 2-1 inner region and the 2-2 inner region, the stress difference acting on one surface of the substrate and the other surface can also be minimized, thus preventing substrate curling in the unfolded region.

[0025] Furthermore, the substrate for the display according to the embodiment minimizes the size difference between the first inner region in the folded region and the first through hole. Therefore, even if the through hole is not located at the center of the hole, the size difference between the first-1 inner region and the first-2 inner region can be minimized.

[0026] Therefore, by minimizing the dimensional difference between the first-1 inner region and the first-2 inner region, the stress difference acting on one surface of the substrate and the other surface can also be minimized, thus preventing substrate curling in the unfolded region.

[0027] Furthermore, the substrate for the display according to the embodiment minimizes the dimensional difference between the first inner region and the first through-hole in the folded region and minimizes the dimensional difference between the second inner region and the second through-hole in the unfolded region. Therefore, even if the through-hole is not located at the center of the hole, the dimensional difference between the first-1 inner region and the first-2 inner region, as well as the dimensional difference between the second-1 inner region and the second-2 inner region, can be minimized.

[0028] Therefore, by minimizing the dimensional differences between the first-1 inner region and the first-2 inner region, as well as between the second-1 inner region and the second-2 inner region, the difference in stress acting on one surface of the substrate and the other surface can also be minimized, thereby preventing substrate curling in the folded and unfolded regions. Attached Figure Description

[0029] Figure 1 This is a perspective view of a flexible display device according to an embodiment.

[0030] Figure 2 This is a perspective view of a substrate for a display according to an embodiment.

[0031] Figure 3 This is a side view of the substrate for a display before folding, according to an embodiment.

[0032] Figure 4 This is a side view of the substrate for a display according to an embodiment after folding.

[0033] Figure 5 This is a top view of one surface of a substrate for a display according to an embodiment.

[0034] Figure 6 This is a top view of another surface of a substrate for a display according to an embodiment.

[0035] Figure 7 It is along Figure 5 A sectional view taken along line A-A'.

[0036] Figure 8 This is a side view of a substrate for a display according to an embodiment.

[0037] Figure 9 It is along Figure 5 Another sectional view taken along line A-A'.

[0038] Figure 10 This is a side view of the substrate for a display according to an embodiment.

[0039] Figure 11 and Figure 12 It is along Figure 5 Another sectional view cut along line A-A'.

[0040] Figure 13 It is along Figure 5 Another sectional view taken along line A-A'.

[0041] Figure 14 This is a side view of the substrate for a display according to an embodiment.

[0042] Figure 15 It is along Figure 5 Another sectional view taken along line A-A'.

[0043] Figure 16 This is another side view of the substrate for a display according to an embodiment.

[0044] Figure 17 This is a top view of one surface of a substrate for a display according to another embodiment.

[0045] Figure 18 This is a top view of another surface of a substrate for a display according to another embodiment.

[0046] Figure 19 It is along Figure 17 A sectional view taken along line B-B'.

[0047] Figure 20 yes Figure 19 A magnified view of region C.

[0048] Figure 21 yes Figure 19 A magnified view of region D.

[0049] Figure 22 It is along Figure 17 A sectional view taken along line B-B'.

[0050] Figure 23 It is along Figure 17 A sectional view taken along line B-B'.

[0051] Figure 24 This is a view used to describe an example of a substrate for a display according to an embodiment. Detailed Implementation

[0052] In the following, embodiments of the invention will be described in detail with reference to the accompanying drawings. However, the spirit and scope of the invention are not limited to the portion of the described embodiments, but can be implemented in various other forms, and one or more elements of the embodiments may be selectively combined and substituted within the spirit and scope of the invention.

[0053] Furthermore, unless otherwise explicitly defined and described, the terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having the same meaning as commonly understood by one of ordinary skill in the art to which the present invention pertains, and terms (e.g., terms defined in commonly used dictionaries) may be interpreted as having the same meaning as in the context of the prior art.

[0054] Furthermore, the terminology used in the embodiments of the present invention is for describing embodiments and is not intended to limit the invention. In this specification, unless specifically stated in the wording, the singular form may also include the plural form, and when described as “at least one (or more than one) of A(and) B and C”, it may include at least one of all combinations that can be combined with A, B and C.

[0055] Furthermore, when describing the elements of embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are used only to distinguish elements from other elements, and the terms are not limited to the substance, order, or sequence of the elements.

[0056] Additionally, when an element is described as being “connected,” “coupled,” or “bonded” to another element, it may include not only that the element is directly connected, coupled, or bonded to other elements, but also that the element is “connected,” “coupled,” or “bonded” through yet another element between that element and another element.

[0057] Furthermore, when described as being formed or arranged “above” or “below” in each element, “above” or “below” can include not only cases where two elements are in direct contact with each other, but also cases where one or more other elements are formed or arranged between the two elements.

[0058] Furthermore, when expressed as "above" or "below", it can include not only the upward direction based on a single element, but also the downward direction based on a single element.

[0059] In the following description, a substrate for a display according to an embodiment will be described with reference to the accompanying drawings.

[0060] Figure 1 This is a perspective view of a flexible display device according to an embodiment.

[0061] refer to Figure 1 The flexible display device 1000 according to the embodiment may include a substrate 100, a display panel 200 disposed above the substrate 100, and a touch panel 300 disposed on the display panel 200.

[0062] The substrate 100 can support the display panel 200 and the touch panel 300. That is, the substrate 100 can be a support substrate that supports the display panel 200 and the touch panel 300.

[0063] The substrate 100 may include materials such as metals. For example, the substrate 100 may include metals, metal alloys, plastics, composite materials (e.g., carbon fiber reinforced plastics, magnetic or conductive materials, glass fiber reinforced materials, etc.), ceramics, sapphire, glass, etc.

[0064] The substrate 100 can be flexible. That is, the substrate 100 can be folded or bent in one direction. In other words, the substrate 100 can be a substrate for a display used in a flexible display device.

[0065] The substrate 100 may include at least two regions. Specifically, the substrate 100 may include a first region 1A and a second region 2A.

[0066] The first region 1A can be defined as the region where the substrate 100 is folded. That is, the first region 1A can be a folded region.

[0067] Furthermore, the second region 2A can be defined as the region of the substrate 100 that is not folded. That is, the second region 2A can be an unfolded region.

[0068] The first region 1A and the second region 2A will be described in detail below.

[0069] The display panel 200 can be disposed above the substrate 100.

[0070] The display panel 200 may include a plurality of pixels, which include switching thin-film transistors, driving thin-film transistors, power storage devices, and organic light-emitting diodes (OLEDs). In the case of OLEDs, deposition can be performed at relatively low temperatures, and OLEDs can be primarily used in flexible display devices for reasons such as low power consumption and high brightness. Here, a pixel refers to the smallest unit used to display an image, and the display panel displays images through a plurality of pixels.

[0071] A display panel may include a substrate, gate lines disposed on the substrate, data lines isolated from the gate lines, and a common power line. Typically, a pixel can be defined by using the gate lines, data lines, and common power line as boundaries.

[0072] The substrate may include a flexible material such as a plastic film, and the display panel 200 may be realized by setting organic light-emitting diodes and pixel circuits on the flexible film.

[0073] The touch panel 300 can be positioned above the display panel 200. The touch panel 300 can enable touch functionality in a flexible display device, and can be omitted in a flexible display device that only displays images and does not have touch functionality.

[0074] The touch panel 300 may include a substrate and touch electrodes disposed on the substrate. The touch electrodes may be capacitive or resistive to sense the position of an input device touched on the flexible display device.

[0075] The substrate of the touch panel 300 may include a material with flexible properties, such as a plastic film, and the touch panel 300 may be realized by placing touch electrodes on the flexible film.

[0076] Meanwhile, the substrate 100 and the display panel 200 can have different sizes.

[0077] For example, the area of ​​substrate 100 may be more than 90% and less than 110% of the area of ​​display panel 200. Specifically, the area of ​​substrate 100 may be more than 95% and less than 105% of the area of ​​display panel 200. More specifically, the area of ​​substrate 100 may be more than 97% and less than 100% of the area of ​​display panel 200.

[0078] When the area of ​​substrate 100 is less than 90% of the area of ​​display panel 200, the supporting force of substrate 100 on display panel 200 or touch panel 300 is reduced, and therefore, curling may occur in the unfolded area of ​​substrate 100. As a result, visibility may decrease when the user visually identifies the screen area, and when a touch is activated, the screen in the touch area may be incomplete due to the curled area, which may lead to touch failure.

[0079] Furthermore, when the area of ​​the substrate 100 increases to more than 110% of the area of ​​the display panel 200, the substrate 100 can ensure the supporting force for the display panel or touch panel. However, the bezel area of ​​the display device, including the substrate, display panel, and touch panel, may increase. Therefore, a wide effective screen area cannot be provided to the user, which may lead to inconvenience in using the display device.

[0080] Furthermore, the area of ​​the first region 1A of the substrate 100 may be more than 1% and less than 30% of the total area of ​​the substrate 100. Specifically, the area 100 of the first region 1A of the substrate 100 may be more than 5% and less than 20% of the total area of ​​the substrate 100. The area of ​​the first region 1A of the substrate 100 may be more than 10% and less than 15% of the total area of ​​the substrate 100.

[0081] When the area of ​​the first region 1A of the substrate 100 is less than 1% of the total area of ​​the substrate 100, cracks may appear at the interface between the folded and unfolded areas of the substrate 100 while the substrate is repeatedly folded and unfolded, thus the folding reliability of the substrate 100 may decrease.

[0082] Furthermore, when the area of ​​the first region 1A of the substrate 100 exceeds 30% of the total area of ​​the substrate 100, curling may occur in the folded area of ​​the display panel 200 when the substrate is folded. Therefore, visibility may decrease when the user visually identifies the screen area, and when a touch is activated, the screen in the touch area may be incomplete due to the curled area, thus potentially causing touch malfunction.

[0083] Additionally, although not shown in the accompanying drawings, a protective cover window for the flexible display device may be provided above the touch panel 300 or above the display panel 200 (when the touch panel is omitted).

[0084] Meanwhile, the substrate 100, display panel 200, and touch panel 300 can be bonded to each other by an adhesive layer or the like. In this case, when the substrate 100 is bonded to the display panel 200, the adhesive layer may not be provided in the first region (i.e., the folded region) of the substrate 100, and the adhesive layer may be provided only in the second region (i.e., the unfolded region) to bond them together.

[0085] Therefore, flexible display devices can be easily folded. However, when the surface flatness of the folding area decreases and the curvature (i.e., flatness) of the folding area increases, the folding area is damaged during the folding process, thus potentially reducing folding reliability.

[0086] The substrate 100 of the flexible display device described below has a structure that can improve the folding reliability of such substrate.

[0087] As described above, the flexible display device includes a substrate 100.

[0088] refer to Figure 2 The substrate 100 can be bent in one direction.

[0089] Specifically, the substrate 100 may include a surface 1S and another surface 2S opposite to the surface 1S. In the substrate 100, the surface 1S or the other surface 2S may be bent facing each other.

[0090] In the following description, such as Figure 2 As shown, the substrate 100 is bent in a direction in which one surface 1S faces the other.

[0091] As described above, the first region 1A and the second region 2A can be defined in the substrate 100. The first region 1A and the second region 2A can be regions defined when the substrate 100 is bent in a direction in which one surface 1S faces each other.

[0092] Specifically, the substrate 100 is bent in one direction, and the substrate 100 can be divided into a first region 1A as a folded region and a second region 2A as an unfolded region.

[0093] refer to Figure 3 and Figure 4 The substrate 100 may include a first region 1A, which is a region where the substrate 100 is bent. The substrate 100 may include a second region 2A, which is not bent and is disposed adjacent to the first region 1A.

[0094] For example, the second region 2A can be formed on the left and right sides of the first region 1A based on the bending direction of the substrate 100. That is, the second region 2A can be disposed at both ends of the first region 1A. That is, the first region 1A can be disposed between the second regions 2A.

[0095] The first region 1A and the second region 2A can be formed on the same substrate 100. That is, the first region 1A and the second region 2A can be formed integrally on the same substrate 100 without separation.

[0096] The dimensions of the first region 1A and the second region 2A can be different from each other. Specifically, the dimension of the second region 2A can be larger than the dimension of the first region 1A.

[0097] The accompanying drawings show a first region 1A located in the central portion of the substrate 100, but the embodiment is not limited to this. That is, the first region 1A may be located in one end and the end region of the substrate 100. In other words, the first region 1A may be located in one end and the end region of the substrate 100, such that the size of the second region 2A is asymmetrical.

[0098] Figure 4 This is a side view of the substrate used for the display after it has been folded.

[0099] refer to Figure 4 The substrate 100 can be folded in one direction around the folding axis. Specifically, a surface 1S can be folded along the folding axis in a direction where they face each other.

[0100] When the substrate 100 is folded in one direction, a first region 1A and a second region 2A can be formed on the substrate 100. That is, the folded region formed by folding the substrate 100 in one direction and the unfolded regions located at both ends of the folded region can be formed in the substrate 100.

[0101] A folded region can be defined as a region that forms a curvature R, while an unfolded region can be defined as a region that does not form a curvature R or has a curvature close to 0.

[0102] refer to Figure 3 and Figure 4 The substrate 100 can be folded in one direction to form an unfolded region, a folded region, and an unfolded region in sequence.

[0103] Multiple holes may be formed in at least one of the first region 1A and the second region 2A to distribute the stress generated when the substrate 100 is folded.

[0104] According to an embodiment, the folding reliability of the substrate for the display can be improved by controlling the size of the hole formed in the second region 2A (i.e., the unfolded region).

[0105] At the same time, Figure 4 The illustration shows a substrate 100 folded so that one surface 1S faces each other, but the embodiment is not limited to this, and another surface 2S can also be folded to face each other.

[0106] For example, in substrate 100, the folded surface can vary depending on the size or area (i.e., the opening region) of the through-hole formed on one or the other surface of substrate 100 as described below.

[0107] That is, the substrate 100 can be folded so that the surfaces of the substrate 100 with larger through-hole sizes or areas (i.e., opening regions) face each other.

[0108] That is, the substrate for the display described below can be folded in different directions depending on the size of the opening area of ​​the through-hole formed in the substrate 100.

[0109] Figure 5 and Figure 6 This is a top view of one surface and another surface of a substrate for a display according to an embodiment. That is, Figure 5 This is a top view of one surface 1S of the substrate. One surface 1S of the substrate is the inner or outer surface of the substrate when it is folded at 100. Figure 6 This is a top view of the other surface 2S of the substrate, which is the inner or outer surface folded when the substrate 100 is folded.

[0110] refer to Figure 5 and Figure 6 Multiple holes can be formed in the substrate 100 for display.

[0111] Holes can be formed in the first region 1A. Specifically, a plurality of first through holes H1, spaced apart from each other, can be formed in the first region 1A. The first through holes H1 can be formed to pass through the substrate 100. Specifically, the first through holes H1 can be formed to pass through one surface 1S and another surface 2S of the substrate 100. Figure 5 and Figure 6 Only three holes formed in the first region 1A are shown, but this is for ease of description. The first region 1A may have more than four holes, which can be similarly applied to the following cross-sectional view.

[0112] The first through hole H1 can be formed to pass through a surface 1S located inside the folding direction and another surface 2S located outside the folding direction.

[0113] Multiple holes formed in the first region 1A are used to disperse the stress generated when the first region is folded. Specifically, due to the compressive stress generated when the substrate 100 is folded, deformation and damage may occur in the first region 1A of the substrate according to the stress.

[0114] Therefore, stress concentration in a specific area of ​​the first region 1A can be prevented by forming a hole in the first region 1A. Thus, damage to the substrate due to compressive stress generated when the substrate 100 is folded can be prevented.

[0115] The first through hole H1 can be formed in the first region 1A in a regular pattern. Alternatively, the first through hole H1 can be formed in the first region 1A in an irregular pattern.

[0116] The first through hole H1 can be formed with a curved surface. Specifically, the first through hole H1 can be formed with a curved surface shape, such as an ellipse, a hemisphere, a circle, etc. For example, the first through hole H1 can be formed in an elliptical shape, which has a short width in the length direction of the substrate 100 and a long width in the width direction corresponding to the folding axis of the substrate 100.

[0117] However, the embodiments are not limited to this, and the first through hole H1 can be formed into a polygonal shape, such as a triangle, a square, etc.

[0118] Meanwhile, the first region 1A and the second region 2A can be distinguished by the presence or absence of a hinge. That is, the folded region and the unfolded region can be distinguished by the presence or absence of a hinge.

[0119] Specifically, multiple hinges may be formed in the first region 1A, and the hinges may not be formed in the second region 2A.

[0120] That is, the folded area can be defined as the area in which the hinge HN is formed.

[0121] The hinge portion HN can be defined as the point where folding begins in the substrate 100. That is, the substrate can be folded starting from the hinge portions at both ends of a plurality of hinge portions.

[0122] Depending on the folding shape of the substrate 100, the hinge portion HN may include multiple hinge portions. The hinge portion HN may be formed at both ends of the substrate 100, which overlap with the column direction in which the first through hole H1 is formed, based on the unidirectional length of the substrate 100 in the width direction.

[0123] Therefore, when the substrate 100 for the display is folded via the hinge HN, the folding area can be easily folded.

[0124] The hinge portion HN can be formed through one surface and another surface of a unidirectional region in the end region of the substrate 100. That is, the hinge portion HN can be defined as a hole formed through two end regions in a unidirectional direction in the end region of the substrate 100.

[0125] The hinge portion HN can be disposed at a position overlapping with the first through hole H1. For example, the hinge portion HN can be disposed at a position overlapping with the first through hole H1 in the width direction of the substrate 100. However, the embodiment is not limited to this, and the hinge portion HN can be disposed at a position offset from the first through hole H1 in the width direction of the substrate 100.

[0126] The shape of the hinge portion HN may be the same as or different from the shape and size of the first through hole H1. For example, the hole may be formed with a curved surface. Specifically, the hole may be formed with a curved surface shape, such as elliptical, hemispherical or circular.

[0127] However, the embodiments are not limited to this. Of course, the hinge can be formed in a polygonal shape, such as a triangle, quadrilateral, or ellipse.

[0128] Holes can be formed in the second region 2A. Specifically, holes can be formed in the second region 2A, which is defined as the unfolded region. That is, holes can be formed in the entire region of the substrate 100 used for the display.

[0129] A plurality of second through holes H2, spaced apart from each other, can be formed in the second region 2A. The second through holes H2 can be formed to pass through the substrate 100. Specifically, the second through holes H2 can be formed to pass through one surface 1S and another surface 2S of the substrate 100.

[0130] That is, the second through hole H2 can be formed to pass through a surface 1S located inside the folding direction and another surface 2S located outside the folding direction.

[0131] The second through hole H2 can be used to reduce the deformation difference caused by heat in the first region 1A where the first through hole H1 is formed.

[0132] Specifically, the difference between heat-induced deformation in the first region 1A and heat-induced deformation in the second region 2A can be reduced by forming holes in both the first region 1A and the second region 2A. Therefore, bending or warping of the substrate used for the display can be prevented.

[0133] The second through hole H2 can be formed in the second region 2A in a regular pattern, or alternatively, the second through hole H2 can be formed in the second region 2A in an irregular pattern.

[0134] The second through hole H2 can be formed simultaneously with a curved surface. Specifically, the second through hole H2 can be formed into a shape with a curved surface, such as an ellipse, a hemisphere, or a circle.

[0135] However, the embodiments are not limited to this, and the second through hole H2 can be formed in a polygonal shape, such as a triangle or a square.

[0136] refer to Figure 7 The first through hole H1 and the second through hole H2 may include opening regions formed as openings on one surface and the other surface of the substrate, respectively.

[0137] Specifically, the first through hole H1 may include an opening region OA1-1 (1-1) and an opening region OA1-2 (1-2). Additionally, the second through hole H2 may include an opening region OA2-1 (2-1) and an opening region OA2-2 (2-2).

[0138] The 1-1 opening region OA1-1 can be a region formed in the first through hole H1 on one surface 1S of the substrate 100, and the 1-2 opening region OA1-2 can be a region formed in the first through hole H1 on another surface 2S of the substrate. That is, the 1-1 opening region OA1-1 and the 1-2 opening region OA1-2 can be defined as surface holes formed on one surface 1S and the other surface 2S of the substrate.

[0139] Furthermore, the second-first opening region OA2-1 is a region formed on one surface 1S of the substrate in the second through hole H2, and the second-second opening region OA2-2 can be a region formed on another surface 2S of the substrate in the second through hole H2. That is, the second-first opening region OA2-1 and the second-second opening region OA2-2 can be defined as surface holes formed on one surface 1S and the other surface 2S of the substrate.

[0140] The size of the opening region OA1-1 (1-1) can correspond to the size of the opening region OA1-2 (1-2). Specifically, the size of the opening region OA1-1 (1-1) and the size of the opening region OA1-2 (1-2) can be the same as or similar to each other. Here, "the same" can be defined as including different tolerance ranges in the process. That is, the size of the opening region of the first through hole H1 can be the same as or similar to each other on one surface 1S and the other surface 2S of the substrate.

[0141] Here, the size of the opening region can be defined as the area of ​​the opening region formed on one surface and the other surface of the substrate. That is, the size of the opening region formed on one surface of the substrate can be defined as the area of ​​the opening region extending through one surface, while the size of the opening region formed on the other surface of the substrate is defined as the area of ​​the opening region extending through the other surface.

[0142] That is, such as Figure 5 and Figure 6 As shown, the size of the opening region can be defined as the surface hole formed on one surface and the other surface in the first through hole and the second through hole passing through one surface and the other surface.

[0143] For example, when the shape of the opening region is circular, the size of the opening region can be defined as the area of ​​the circle; when the shape of the opening region is polygonal (e.g., rectangle or triangle), the size of the opening region can be defined as the area of ​​the polygon.

[0144] Meanwhile, the second region 2A may include a variable region, in which the size of the opening region on one surface and the other surface of the substrate is different. Specifically, the size of the 2-1 opening region OA2-1 of the second through hole H2 formed in the second region 2A may be different from the size of the 2-2 opening region OA2-2.

[0145] Specifically, the size of the 2-1 opening region OA2-1 can be larger than the size of the 2-2 opening region OA2-2. Therefore, a variable region with different sizes for the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 can be formed in the second region 2A.

[0146] In addition, the size of the second-2 opening region OA2-2 can be smaller than the size of the first-1 opening region OA1-1 and the size of the second-2 opening region OA1-2.

[0147] In addition, the size of the 2-1 opening region OA2-1 is the same as or similar to the size of the 1-1 opening region OA1-1 and the 1-2 opening region OA1-2.

[0148] In the second through hole H2, based on the folding direction of the substrate, the size of the opening area formed on the inner folded surface of the substrate can be larger than the size of the opening area formed on the outer folded surface of the substrate.

[0149] That is, in the second through hole H2 formed in the variable region of the second region 2A, the size of the second-1 opening region OA2-1 formed on one surface 1S of the substrate can be larger than the size of the second-2 opening region OA2-2 formed on the other surface 2S of the substrate.

[0150] For example, multiple second through holes H can be formed in the second region 2A, and each hole can include the second-1 opening region OA2-1 and the second-2 opening region OA2-2.

[0151] The second region 2A may include regions with different sizes than the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2. For example, the second region 2A may contain variable regions and fixed regions. In the variable region, the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 have different sizes, while in the fixed region, the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 have the same or similar sizes.

[0152] In this case, the variable regions with different sizes of the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 can be formed to be approximately 40% to 60% of the size of the entire region of each of the second regions 2A located on the left and right sides of the first region.

[0153] When the variable area with different dimensions between the 2-1 opening area OA2-1 and the 2-2 opening area OA2-2 is less than about 40% of the entire area of ​​each second area 2A, the stress generated in the second area is small, so the first area 1A cannot be effectively flattened. When the variable area exceeds about 60%, the stress generated in the second area becomes too large, so poor adhesion may occur during the bonding process with other panels.

[0154] Meanwhile, in the variable region, the size of the 2-1 opening region OA2-1 can be greater than 1 times and less than 2 times the size of the 2-2 opening region OA2-2.

[0155] That is, the size of the 2-1 opening region OA2-1 can be larger than the size of the 2-2 opening region OA2-2 and can be less than twice the size of the 2-2 opening region OA2-2.

[0156] When the size of the 2-1 opening region OA2-1 is no different from the size of the 2-2 opening region OA2-2, a stress difference may not occur between one surface and the other surface of the substrate. When the size of the 2-1 opening region OA2-1 is more than twice the size of the 2-2 opening region OA2-2, the second region may be excessively bent as the stress difference increases, and therefore poor adhesion may occur during the bonding process with other panels.

[0157] The dimensional difference between the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 may be related to the stress generated in the second region 2A. Specifically, since the dimensions of the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 are different from each other, the magnitudes of the stresses applied to one surface 1S and the other surface 2S of the substrate in the second region 2A of the substrate 100 may be different.

[0158] That is, in the second-1 opening region OA2-1 with a larger opening size in each second through hole, the stress may be generated at a smaller size due to the stress dispersion in the second-1 opening region OA2-1 with a larger opening size, while the stress may be generated at a relatively larger size in the second-2 opening region OA2-2 with a smaller opening size.

[0159] Therefore, since one surface 1S of the substrate, where the stress is less, tends to contract in the variable region, while the other surface 2S of the substrate, where the stress is greater, tends to expand, the substrate may bend in the direction of the other surface 2S of the substrate in the variable region of the second region where openings of different sizes are formed.

[0160] That is, reference Figure 8 In the region of the second region 2A where the size of the second-1 opening region OA2-1 is larger than the size of the second-2 opening region OA2-2, the substrate 100 can be bent in the direction of the other surface 2S of the substrate. That is, the second region 2A can be bent such that the curvature of the second region is greater than the curvature of the first region 1A.

[0161] Therefore, since the second region 2A bends and curls in the direction of the other surface 2S of the substrate, the first region between the second regions 2A can be naturally planarized. That is, a force pressing on the second region 2A is generated due to the stress difference in the second region 2A, and the first region between the second regions 2A can be naturally planarized by this force generated in the second region.

[0162] Specifically, refer to Figure 8 At the maximum height, the distance d between the first region 1A and the second region 2A can be from about 0.1 mm to about 5 mm. That is, the second region 2A can be formed to be curled about 0.1 mm to about 5 mm relative to the first region 1A, so that the first region 1A can be naturally flattened by the second region 2A.

[0163] Furthermore, the ripples formed in the first region 1A during the rolling process are also pushed towards the second region 2A, thus reducing the ripples in the first region 1A and improving the surface smoothness of the first region 1A. That is, by reducing the ripples in the first region 1A, the surface roughness of the first region 1A can be made smaller than that of the second region 2A.

[0164] Therefore, the substrate for the display according to the embodiment can prevent the first region, which is the folding area, from curling and improve surface flatness. Thus, defects such as cracks in the folding area during folding can be reduced, thereby improving the reliability of the flexible display device.

[0165] At the same time, refer to Figure 9 and Figure 10 ,and Figure 7 and Figure 8 Unlike other materials, the size of the opening region formed on the second surface 2S of the substrate 100 can be larger than the size of the opening region formed on the first surface 1S.

[0166] refer to Figure 9 In the variable region of the second region 2A, the size of the second-first opening region OA2-1 can be different from the size of the second-second opening region OA2-2. Specifically, the size of the second-second opening region OA2-2 can be larger than the size of the second-first opening region OA2-1.

[0167] In addition, the size of the second-first opening region OA2-1 can be smaller than the size of the first-first opening region OA1-1 and the size of the first-second opening region OA1-2.

[0168] In addition, the size of the second-2 opening region OA2-2 can be the same as or similar to the size of the first-1 opening region OA1-1 and the first-2 opening region OA1-2.

[0169] In the second through hole H2, based on the folding direction of the substrate, the size of the opening area formed on the outer folded surface of the substrate can be larger than the size of the opening area formed on the inner folded surface of the substrate.

[0170] That is, in the second through hole H2, the size of the second-2 opening region OA2-2 formed on the other surface 2S of the substrate can be larger than the size of the second-1 opening region OA2-1 formed on one surface 1S of the substrate.

[0171] For example, multiple second through holes H can be formed in the second region 2A, and each hole can include the second-1 opening region OA2-1 and the second-2 opening region OA2-2.

[0172] The second region 2A may include regions with different sizes of the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2. For example, there may be variable regions and fixed regions in the second region 2A. In the variable region, the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 have different sizes, while in the fixed region, the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 have the same or similar sizes.

[0173] In this case, the variable regions with different sizes of the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 can be included as approximately 40% to 60% of the entire area of ​​each of the second regions 2A set on the left and right sides of the first region.

[0174] When the variable area with different dimensions between the 2-1 opening area OA2-1 and the 2-2 opening area OA2-2 is less than about 40% of the entire area of ​​each second area 2A, the stress generated in the second area is small, so the first area 1A cannot be effectively flattened. When the variable area exceeds about 60%, the stress generated in the second area becomes too large, and therefore poor adhesion may occur during the bonding process with other panels.

[0175] The size of the 2-2 opening region OA2-2 can be greater than 1 times and less than 2 times the size of the 2-1 opening region OA2-1.

[0176] That is, the size of the second-2 opening region OA2-2 can be larger than the size of the second-1 opening region OA2-1 and can be less than twice the size of the second-1 opening region OA2-1.

[0177] When the size of the 2-1 opening region OA2-1 is no different from the size of the 2-2 opening region OA2-2, there may be no stress difference between one surface and the other surface of the substrate. When the size of the 2-2 opening region OA2-2 is more than twice the size of the 2-1 opening region OA2-1, the second region may be excessively bent as the stress difference increases, and therefore poor adhesion may occur during the bonding process with other panels.

[0178] The dimensional difference between the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 may be related to the stress generated in the second region 2A. Specifically, since the dimensions of the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 are different from each other, the magnitudes of the stresses applied to one surface 1S and the other surface 2S of the substrate 100 in the second region 2A of the substrate 100 may be different.

[0179] That is, in the region where one surface of the substrate 100 overlaps with another surface, the stress may be generated at a smaller rate in the second-2 opening region OA2-2 with a larger opening size, while the stress may be generated at a relatively larger rate in the second-1 opening region OA2-1 with a smaller opening size.

[0180] Therefore, since the other surface 2S of the substrate, where the stress is less, tends to contract, while the one surface 1S of the substrate, where the stress is greater, tends to extend, the substrate may bend in the direction of one surface 1S of the substrate in the second region where openings of different sizes are formed.

[0181] That is, reference Figure 10In the variable region where the size of the second-2 opening region OA2-2 in the second region 2A is larger than the size of the second-1 opening region OA2-1, the substrate 100 can be bent in the direction of one surface 1S of the substrate.

[0182] Therefore, since the second region 2A is bent and compressed in the direction of one surface 1S of the substrate, the first region 1A between the second regions 2A can be naturally planarized. That is, a pressing force is generated on the second region 2A due to the stress difference in the second region 2A, and the first region 1A between the second regions 2A can be naturally planarized by the force generated in the second region.

[0183] Specifically, refer to Figure 10 At the minimum height, the distance d between the first region 1A and the second region 2A can be from about 0.1 mm to about 5 mm. That is, the second region 2A can be formed to press the first region 1A by about 0.1 mm to about 5 mm, so the first region 1A can be naturally flattened by the second region 2A.

[0184] In addition, the ripples formed in the first region 1A during the rolling process are also pushed to the second region 2A, thus reducing the ripples in the first region 1A and improving the surface smoothness of the first region 1A.

[0185] Therefore, the substrate for the display according to the embodiment can prevent the first region, which serves as the folding area, from curling and improve surface flatness. Consequently, defects such as cracks in the folding area during folding can be reduced, thereby improving the reliability of the flexible display device.

[0186] At the same time, refer to Figure 11 and Figure 12 ,and Figure 7 and Figure 8 Unlike other opening regions, the size of the 2-1 opening region OA2-1 is larger than the size of the 2-2 opening region OA2-2, and it can be formed to gradually increase or decrease.

[0187] refer to Figure 11 and Figure 12 The dimensions of the opening region OA2-1 (2-1) can differ from the dimensions of the opening region OA2-2 (2-2). Specifically, refer to... Figure 11 The size of the opening region OA2-1 in section 2-1 can be larger than the size of the opening region OA2-2 in section 2-2. Additionally, refer to... Figure 12 The size of the second-2 opening region OA2-2 can be larger than the size of the second-1 opening region OA2-1.

[0188] For example, multiple second through holes H2 can be formed in the second region 2A, and each hole may include a second-1 opening region OA2-1 and a second-2 opening region OA2-2.

[0189] In at least one second region 2A, the dimensions of the second-first opening region OA2-1 and the second-second opening region OA2-2 may be different from each other. For example, there may be variable regions and fixed regions in the second region 2A. In the variable region, the dimensions of the second-first opening region OA2-1 and the second-second opening region OA2-2 are different, while in the fixed region, the dimensions of the second-first opening region OA2-1 and the second-second opening region OA2-2 are the same or similar.

[0190] In this case, the regions with different sizes of the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 can be included as approximately 40% to 60% of the entire region of each of the second regions 2A located on the left and right sides of the first region.

[0191] When the variable area with different dimensions between the 2-1 opening area OA2-1 and the 2-2 opening area OA2-2 is less than about 40% of the entire area of ​​each second area 2A, the stress generated in the second area is small, so the first area 1A cannot be effectively flattened. When the variable area exceeds about 60%, the stress generated in the second area becomes too large, and therefore poor adhesion may occur during the bonding process with other panels.

[0192] Furthermore, in regions where the dimensions of the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 are different, the size of the 2-1 opening region OA2-1 can be formed to gradually decrease or gradually increase.

[0193] refer to Figure 11 In the region where the dimensions of the second-1 opening region OA2-1 and the second-2 opening region OA2-2 are different, the size of the second-1 opening region OA2-1 can be gradually reduced while moving along the direction of the first region 1A.

[0194] Alternatively, in regions where the dimensions of the second-1 opening region OA2-1 and the second-2 opening region OA2-2 are different, the size of the second-1 opening region OA2-1 can be gradually increased while moving in the direction of the first region 1A.

[0195] Alternatively, in regions where the dimensions of the second-1 opening region OA2-1 and the second-2 opening region OA2-2 are different, the size of the second-1 opening region OA2-1 may gradually decrease and then increase while moving along the direction of the first region 1A, or it may increase and then decrease.

[0196] Alternatively, refer to Figure 12 In the region where the dimensions of the second-1 opening region OA2-1 and the second-2 opening region OA2-2 are different, the size of the second-2 opening region OA2-2 can be gradually reduced while moving along the direction of the first region 1A.

[0197] Alternatively, in regions where the dimensions of the second-1 opening region OA2-1 and the second-2 opening region OA2-2 are different, the size of the second-2 opening region OA2-2 can be gradually increased while moving in the direction along the first region 1A.

[0198] Alternatively, in the region where the dimensions of the second-1 opening region OA2-1 and the second-2 opening region OA2-2 are different, the size of the second-2 opening region OA2-2 may gradually decrease and then increase while moving along the direction of the first region 1A, or it may increase and then decrease.

[0199] Therefore, by gradually changing the magnitude of the stress generated in the regions where the dimensions of the opening region OA2-1 in the second-1 and the opening region OA2-2 in the second-2 are different, cracks or deformations in the second region due to sudden changes in stress can be prevented.

[0200] At the same time, refer to Figure 13 and 14 The second region 2A may include multiple such regions, in which the size of the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 are different.

[0201] Based on the dimensional difference between the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2, the second region 2A can be defined as two regions. Specifically, the second region 2A may include the 2-1 region 2-1A and the 2-2 region 2-2A. In the 2-1 region 2-1A, the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 have different dimensions, while in the 2-2 region 2-2A, the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 have the same or similar dimensions.

[0202] In this case, the second region 2A may include at least two or more second-1 regions 2-1A, in which the second-1 opening region OA2-1 and the second-2 opening region OA2-2 have different sizes.

[0203] In this case, the second-1 region 2-1A can be included as approximately 40% to 60% of the entire area of ​​each second region 2A located on the left and right sides of the first region.

[0204] When the second region 2-1A is less than about 40% of the entire area of ​​each second region 2A, the stress generated in the second region is small, so the first region 1A cannot be effectively flattened. When the second region 2-1A exceeds about 60%, the stress generated in the second region becomes too large, and therefore poor adhesion may occur during the bonding process with other panels.

[0205] The dimensional difference between the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 may be related to the stress generated in the second region 2A. Specifically, since the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 are different in size, the magnitude of the stress applied to one surface 1S and the other surface 2S of the substrate 100 in the second region 2A of the substrate 100 may be different.

[0206] That is, in the region where one surface of the substrate 100 overlaps with another surface, the stress may be generated at a relatively small rate in the second-1 opening region OA2-1 with a larger opening size, while the stress may be generated at a relatively large rate in the second-2 opening region OA2-2 with a smaller opening size.

[0207] Therefore, since one surface 1S of the substrate, where the stress is less, tends to contract, while the other surface 2S of the substrate, where the stress is greater, tends to extend, the substrate may bend in the direction of the other surface 2S of the substrate in the second region where openings of different sizes are formed.

[0208] Therefore, refer to Figure 14 In the second region 2A, the substrate 100 can be bent in the direction of the other surface 2S of the substrate in the second-1 region 2-1A. That is, there can be at least two such regions in the second region 2A, in which the substrate is bent in the direction of the other surface 2S of the substrate.

[0209] Therefore, since the second region 2A bends and curls in the direction of the other surface 2S of the substrate, the first region between the second regions 2A can be naturally planarized. That is, a force pressing on the second region 2A is generated due to the stress difference in the second region 2A, and the first region between the second regions 2A can be naturally planarized by this force generated in the second region.

[0210] Specifically, refer to Figure 14At the maximum height, the distance d between the first region 1A and the second region 2A can be from about 0.1 mm to about 5 mm. That is, the second region 2A can be formed to be curled about 0.1 mm to about 5 mm relative to the first region 1A, so that the first region 1A can be naturally flattened by the second region 2A.

[0211] In addition, the ripples formed in the first region 1A during the rolling process are also pushed to the second region 2A, thus reducing the ripples in the first region 1A and improving the surface smoothness of the first region 1A.

[0212] Therefore, the substrate for the display according to the embodiment can prevent the first region, which is the folding area, from curling and improve surface flatness. Thus, defects such as cracks in the folding area during the folding process can be reduced, thereby improving the reliability of the flexible display device.

[0213] At the same time, refer to Figure 15 and 16 The second region 2A may include multiple such regions, in which the dimensions of the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 are different.

[0214] The second region 2A can be defined as two regions based on the size difference between the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2. Specifically, the second region 2A may include the 2-1 region 2-1A and the 2-2 region 2-2A. In the 2-1 region 2-1A, the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 have different sizes, while in the 2-2 region 2-2A, the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 have the same or similar sizes.

[0215] In this case, the second region 2A may include at least two or more second-1 regions 2-1A, in which the second-1 opening region OA2-1 and the second-2 opening region OA2-2 have different sizes.

[0216] In this case, the second-1 region 2-1A can be included as approximately 40% to 60% of the entire area of ​​each second region 2A located on the left and right sides of the first region.

[0217] When the second region 2-1A is less than about 40% of the entire area of ​​each second region 2A, the stress generated in the second region is small, so the first region 1A cannot be effectively flattened. When the second region 2-1A exceeds about 60%, the stress generated in the second region becomes too large, and therefore poor adhesion may occur during the bonding process with other panels.

[0218] The dimensional difference between the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 may be related to the stress generated in the second region 2A. Specifically, since the dimensions of the 2-1 opening region OA2-1 and the 2-2 opening region OA2-2 are different from each other, the magnitudes of the stresses applied to one surface 1S and the other surface 2S of the substrate 100 in the second region 2A of the substrate 100 may be different.

[0219] That is, in the region where one surface of the substrate 100 overlaps with another surface, the stress may be generated at a smaller rate in the second-2 opening region OA2-2 with a larger opening size, while the stress may be generated at a relatively larger rate in the second-1 opening region OA2-1 with a smaller opening size.

[0220] Therefore, since the other surface 2S of the substrate, where the stress is less, tends to contract, while the one surface 1S of the substrate, where the stress is greater, tends to extend, the substrate may bend in the direction of one surface 1S of the substrate in the second region where openings of different sizes are formed.

[0221] Therefore, refer to Figure 16 In the second region 2A, the substrate 100 can be bent in the direction of one surface 1S of the substrate in the second-1st region 2-1A of the substrate. That is, there can be at least two or more such regions in the second region 2A, in which the substrate is bent in the direction of one surface 1S of the substrate.

[0222] Therefore, since the second region 2A is bent and curled in the direction of one surface 1S of the substrate, the first region between the second regions 2A can be naturally planarized. That is, a pressing force is generated on the second region 2A due to the stress difference in the second region 2A, and the first region between the second regions 2A can be naturally planarized by the force generated in the second region.

[0223] Specifically, refer to Figure 16 At the minimum height, the distance d between the first region 1A and the second region 2A can be from about 0.1 mm to about 5 mm. That is, the second region 2A can be formed to press the first region 1A by about 0.1 mm to about 5 mm, so the first region 1A can be naturally flattened by the second region 2A.

[0224] In addition, the ripples formed in the first region 1A during the rolling process are also pushed to the second region 2A, thus reducing the ripples in the first region 1A and improving the surface smoothness of the first region 1A.

[0225] Therefore, the substrate for the display according to the embodiment can prevent the first region, which is the folding area, from curling and improve surface flatness. Thus, defects such as cracks in the folding area during the folding process can be reduced, thereby improving the reliability of the flexible display device.

[0226] In the following text, reference will be made to Figures 17 to 23 A substrate for a display is described according to another embodiment. In the description of the substrate for a display according to another embodiment, descriptions of content that is the same as or similar to that of the substrate for a display according to the above embodiment are omitted.

[0227] Figure 17 and Figure 18 This is a top view of one surface and another surface of a substrate for a display according to another embodiment. That is, Figure 17 This is a top view of one surface 1S of the substrate, which is either the inner or outer surface when the substrate 100 is folded. Figure 18 This is a top view of the other surface 2S of the substrate, which is the inner or outer surface of the substrate when it is folded at 100.

[0228] refer to Figure 17 and 18 Multiple through holes H1 and H2 can be formed in the substrate 100 for display.

[0229] The descriptions of the shapes of the through holes H1 and H2, the hinge portion HN, etc., are the same as those of the substrate for the display according to the above embodiment, and therefore the following descriptions will be omitted.

[0230] refer to Figure 19 The first through-hole H1 and the second through-hole H2 may each include an internal region formed by passing through one surface and the other surface of the substrate. That is, the internal region can be defined as the internal region of the substrate exposed by the through-hole.

[0231] Specifically, the first through hole H1 may include the first internal region OA1-1 and the first internal region OA1-2. Additionally, the second through hole H2 may include the second internal region OA2-1 and the second internal region OA2-2.

[0232] The first-1 internal region OA1-1 can be a region formed in the first through hole H1 on one surface 1S of the substrate 100, and the first-2 internal region OA1-2 can be a region formed in the first through hole H1 on another surface 2S of the substrate 100. That is, the first-1 internal region OA1-1 and the first-2 internal region OA1-2 can be defined as surface holes formed on one surface 1S and the other surface 2S of the substrate.

[0233] Additionally, the first through-hole H1 may include a first through-hole TH1. The first-1 inner region OA1-1 may have a narrower width as it extends from one surface of the substrate to another, while the first-2 inner region OA1-2 may have a narrower width as it extends from one surface of the substrate to another.

[0234] The first through hole TH1 can be defined as the contact point between the region with the minimum width of the inner region OA1-1 (1-1) and the region with the minimum width of the inner region OA1-2 (1-2).

[0235] Furthermore, the second-1 internal region OA2-1 can be a region formed on one surface 1S of the substrate in the second through hole H2, and the second-2 internal region OA2-2 can be a region formed on another surface 2S of the substrate in the second through hole H2. That is, the second-1 internal region OA2-1 and the second-2 internal region OA2-2 can be defined as surface holes formed on one surface 1S and the other surface 2S of the substrate.

[0236] Additionally, the second through-hole H2 may include a second through-hole TH2. The inner region OA2-1 of the 2-1 may have a narrower width as it extends from one surface of the substrate to another, and the inner region OA2-2 of the 2-2 may have a narrower width as it extends from one surface of the substrate to another.

[0237] The second through hole TH2 can be defined as the contact point between the region with the minimum width of the inner region OA2-1 of the second-1 and the region with the minimum width of the inner region OA2-2 of the second-2.

[0238] The first inner region OA1-1 may have a first width W1, the first inner region OA1-2 may have a second width W2, and the first through hole TH1 may have a third width W3.

[0239] The first width W1 can be defined as the maximum width of the inner region OA1-1 of the first-1, and the second width W2 can be defined as the maximum width of the inner region OA1-2 of the first-2.

[0240] The dimensions of the first width W1 and the second width W2 can be the same or similar. Furthermore, the dimension of the first width W1 can be larger than the dimension of the third width W3. In other words, the dimensions of the first width W1 and the second width W2 can be larger than the dimension of the third width W3.

[0241] Additionally, the inner region OA2-1 of the second-first phase may have a first width W1, the inner region OA2-2 of the second-second phase may have a second width W2, and the second through hole TH2 may have a third width W3.

[0242] The first width W1 can be defined as the maximum width of the inner region OA2-1 of the second-first region, and the second width W2 can be defined as the maximum width of the inner region OA2-2 of the second-second region.

[0243] The dimensions of the first 'width W1' and the second 'width W2' can be the same or similar. Furthermore, the dimension of the first 'width W1' can be larger than the dimension of the third 'width W3'. In other words, the dimensions of the first 'width W1' and the second 'width W2' can both be larger than the dimension of the third 'width W3'.

[0244] refer to Figure 20 and 21 The first width W1 and the third width W3, or the second width W2 and the third width W3, can differ by a first distance d1+d2. Additionally, the first width W1' and the third width W3', or the second width W2' and the third width W3', can differ by a second distance d1'+d2'.

[0245] In this case, the magnitude of the second distance d1'+d2' can be smaller than the magnitude of the first distance d1+d2. Specifically, the second distance d1'+d2' can be less than 20 μm. Conversely, the first distance d1+d2 can exceed 20 μm.

[0246] That is, the size difference between the second-1 inner region OA2-1 and the second-2 inner region OA2-2 formed in the second region 2A, which is the unfolded region, and the second through hole TH2 can be smaller than the size difference between the first-1 inner region OA1-1 and the first-2 inner region OA1-2 formed in the first region 1A, which is the folded region, and the first through hole TH1.

[0247] In other words, by making the first width W1' and the second width W2' of the second through hole H2 smaller than the first width W1 and the second width W2 of the first through hole H1, the difference between the maximum width of the internal region and the through hole can be reduced.

[0248] That is, by making the curvature of the inner surfaces of the second-1 inner region OA2-1 and the second-2 inner region OA2-2 of the second through hole H2 smaller than the curvature of the inner surfaces of the first-1 inner region OA1-1 and the first-2 inner region OA1-2 of the first through hole H1, the maximum width of the second-1 inner region OA2-1 and the second-2 inner region OA2-2 can be reduced.

[0249] That is, in the first through hole H1 and the second through hole H2, the maximum width of the internal region is related to the curvature of the inner surface of the internal region. As the curvature increases, the distance between the inner surfaces increases, so the width of the internal region can be increased.

[0250] Therefore, in the substrate for a display according to the embodiment, by forming the curvature of the inner surface of the inner region in the second through hole H2 of the unfolded region to be relatively smaller than the curvature of the inner region of the first through hole H1, the maximum width of the inner region, which is defined as the distance between the inner surfaces in the inner region, can be reduced.

[0251] When the size difference between the second-1 inner region OA2-1 and the second-2 inner region OA2-2 and the second through hole TH2 increases, and when the second through hole TH2 is not located at the center of the second through hole H2, the size difference between the size of the second-1 inner region OA2-1 and the size of the second-2 inner region OA2-2 formed on one surface of the substrate increases by the same amount as the distance from the center.

[0252] Therefore, the stress difference between one surface of the substrate and the other surface of the substrate increases, and thus, curling may occur due to the stress difference between one surface of the substrate and the other surface of the substrate, i.e., curling phenomenon.

[0253] Therefore, the substrate for the display according to the embodiment minimizes the size difference between the second inner region and the second through hole in the unfolded area. Thus, even if the through hole is not located at the center of the hole, the size difference between the second-1 inner region and the second-2 inner region can be minimized.

[0254] Therefore, by minimizing the dimensional difference between the 2-1 inner region and the 2-2 inner region, the stress difference acting on one surface of the substrate and the other surface can also be minimized, thus preventing substrate curling in the unfolded region.

[0255] In the following text, reference will be made to Figure 22A substrate for a display is described according to yet another embodiment. In the description of the substrate for a display according to yet another embodiment, descriptions that are the same as or similar to those for the substrate for a display according to the above embodiment, another embodiment, and yet another embodiment will be omitted, and the same structures will be indicated by the same reference numerals.

[0256] refer to Figure 22 Unlike the embodiments described above, in another embodiment of the substrate for a display, the size of the first distance d1+d2 can be smaller than the size of the second distance d1'+d2'. Specifically, the first distance d1+d2 can be less than 20 μm. Furthermore, the second distance d1'+d2' can exceed 20 μm.

[0257] That is, the size difference between the first-1 inner region OA1-1 and the first-2 inner region OA1-2 of the first through hole H1 formed in the first region 1A, which is the folded region, and the through hole TH1 can be smaller than the size difference between the second-1 inner region OA2-1 and the second-2 inner region OA2-2 of the second through hole H2 formed in the second region 2A, which is the unfolded region, and the second through hole TH2.

[0258] In other words, by making the first width W1 and the second width W2 of the first through hole H1 smaller than the first width W1' and the second width W2' of the second through hole H2, the difference between the maximum width of the internal region and the through hole can be reduced.

[0259] That is, by making the curvature of the inner surfaces of the first-1 inner region OA1-1 and the first-2 inner region OA1-2 of the first through hole H1 smaller than the curvature of the inner surfaces of the second-1 inner region OA2-1 and the second-2 inner region OA2-2 of the second through hole H2, the maximum width of the first-1 inner region OA1-1 and the first-2 inner region OA1-2 can be reduced.

[0260] That is, in the first through hole H1 and the second through hole H2, the maximum width of the internal region is related to the curvature of the inner surface of the internal region. As the curvature increases, the distance between the inner surfaces increases, so the width of the internal region can be increased.

[0261] Therefore, in the substrate for a display according to the embodiment, by forming the curvature of the inner surface of the inner region of the first through hole H1 of the folded region to be relatively smaller than the curvature of the inner region of the second through hole H2, the maximum width of the inner region, which is defined as the distance between the inner surfaces in the inner region, can be reduced.

[0262] When the size difference between the first internal region OA1-1 and the first internal region OA1-2 and the first through hole TH1 increases, and when the first through hole TH1 is not located at the center of the first through hole H1, the size difference between the first internal region OA1-1 and the first internal region OA1-2 formed on one surface of the substrate increases by the same amount as the distance from the center.

[0263] Therefore, the stress difference between one surface of the substrate and the other surface of the substrate increases, and thus, curling may occur due to the stress difference between one surface of the substrate and the other surface of the substrate, i.e., curling phenomenon.

[0264] Therefore, the substrate for the display according to the embodiment minimizes the size difference between the first inner region and the first through hole in the folded region, so that even if the through hole is not located at the center of the hole, the size difference between the first-1 inner region and the first-2 inner region can be minimized.

[0265] Therefore, by minimizing the dimensional difference between the first-1 inner region and the first-2 inner region, the stress difference acting on one surface of the substrate and the other surface can also be minimized, thus preventing substrate curling in the folded region.

[0266] In the following text, reference will be made to Figure 23 A substrate for a display is described according to yet another embodiment. In the description of the substrate for a display according to yet another embodiment, descriptions that are the same as or similar to those for the substrate for a display according to the above embodiment, another embodiment, and yet another embodiment will be omitted, and the same structures will be indicated by the same reference numerals.

[0267] refer to Figure 23 Unlike the embodiments described above, in a substrate for a display according to yet another embodiment, the magnitudes of the first distance d1+d2 and the second distance d1'+d2' can correspond to each other. That is, the magnitudes of the first distance d1+d2 and the second distance d1'+d2' can be the same or similar. Specifically, the magnitudes of the first distance d1+d2 and the second distance d1'+d2' can be less than 20 μm.

[0268] That is, the size difference between the first-1 inner region OA1-1 and the first-2 inner region OA1-2 of the first through hole H1 formed in the first region 1A, which is the folded region, and the first through hole TH1 can correspond to the size difference between the second-1 inner region OA2-1 and the second-2 inner region OA2-2 of the second through hole H2 formed in the second region 2A, which is the unfolded region, and the second through hole TH2.

[0269] That is, by forming the curvature of the inner surfaces of the first-1 inner region OA1-1 and the first-2 inner region OA1-2 of the first through hole H1 and the curvature of the inner surfaces of the second-1 inner region OA2-1 and the second-2 inner region OA2-2 of the second through hole H2 to correspond to each other, the maximum width of the first-1 inner region OA1-1 and the first-2 inner region OA1-2 and the maximum width of the second-1 inner region OA2-1 and the second-2 inner region OA2-2 can be reduced.

[0270] In the first through hole H1 and the second through hole H2, the maximum width of the internal region is related to the curvature of the inner surface of the internal region. As the curvature increases, the distance between the inner surfaces increases, so the width of the internal region can be increased.

[0271] Therefore, in the substrate for a display according to the embodiment, by making the curvature of the inner surface of the inner region in the first through hole H1 of the folded region and the curvature of the inner surface of the inner region in the second through hole H2 of the unfolded region smaller, the maximum width of the inner region, which is defined as the distance between the inner surfaces in the inner region, can be reduced.

[0272] When the size difference between the first internal region OA1-1 and the first internal region OA1-2 and the first through hole TH1, and the size difference between the second internal region OA2-1 and the second internal region OA2-2 and the second through hole TH2 increases, and the first through hole TH1 is not located at the center of the first through hole H1, or the second through hole TH2 is not located at the center of the second through hole H2, the size difference between the first internal region OA1-1 and the first internal region OA1-2, and the size difference between the second internal region OA2-1 and the second internal region OA2-2 formed on the substrate increases.

[0273] Therefore, the stress difference between one surface of the substrate and the other surface of the substrate increases, and thus, curling may occur due to the stress difference between one surface of the substrate and the other surface of the substrate, i.e., curling phenomenon.

[0274] Therefore, the substrate for a display according to another embodiment minimizes the size difference between the first inner region and the first through hole in the folded region, and also minimizes the size difference between the second inner region and the second through hole in the unfolded region. Thus, even if the through hole is not located at the center of the hole, the size difference between the first-1 inner region and the first-2 inner region, as well as the size difference between the second-1 inner region and the second-2 inner region, can be minimized.

[0275] Therefore, by minimizing the dimensional differences between the first-1 inner region and the first-2 inner region, as well as between the second-1 inner region and the second-2 inner region, the stress difference acting on one surface of the substrate and the other surface can also be minimized, thus preventing substrate curling in the folded and unfolded regions.

[0276] Figure 24 This is a view used to describe an example of a substrate for a display according to an embodiment.

[0277] refer to Figure 24 The substrate for a display according to the embodiment can be applied to a flexible display device for display.

[0278] For example, the substrate for a display according to the embodiments can be applied to flexible display devices, such as mobile phones or tablet computers.

[0279] This substrate for displays can be applied to flexible display devices such as mobile phones and tablets, which can be bent or folded.

[0280] The substrate used for the display is applied to flexible display devices such as mobile phones and tablets, which are flexible, bendable, or foldable, and can improve the reliability of flexible display devices by improving the folding reliability of flexible display devices that are repeatedly folded or restored.

[0281] The features, structures, and effects described in the above embodiments are all included in at least one embodiment of the present invention, but are not limited to one embodiment. Furthermore, those skilled in the art can combine or modify the features, structures, and effects shown in each embodiment for use in other embodiments. Therefore, it should be understood that such combinations and modifications are included within the scope of the present invention.

[0282] Furthermore, the descriptions of the above embodiments are merely examples and do not limit the present invention. It will be apparent to those skilled in the art that the present invention can be readily implemented in many different forms without altering the technical concept or essential characteristics of the invention. For example, elements of the exemplary embodiments described herein can be modified and implemented. Additionally, it should be understood that differences associated with these variations and applications are included within the scope of the invention as defined by the appended claims.

Claims

1. A substrate for a display, the substrate comprising: A surface and another surface opposite to said one surface; as well as First and Second Zones The first region is positioned between the second regions. A plurality of first through holes spaced apart from each other are formed in the first region, and a plurality of second through holes spaced apart from each other are formed in the second region. In the first region, a plurality of hinge portions are formed that extend through the two end regions of the substrate in the width direction of the substrate. Each of the plurality of second through holes includes a second-1 opening region of one surface opening and a second-2 opening region of the other surface opening. The second region includes: a variable region whose size is different from that of the second-1 opening region; and a fixed region whose size is the same as that of the second-1 opening region and the second-2 opening region.

2. The substrate for a display according to claim 1, wherein, In the plurality of second through holes, the second through holes formed at the two end regions of the substrate are spaced apart from the ends of the substrate.

3. The substrate for a display according to claim 1, wherein, The surfaces are folded so that they face each other. Wherein, the size of the second-1st opening region in the variable region is greater than the size of the second-2nd opening region in the variable region.

4. The substrate for a display according to claim 1, wherein, The plurality of hinge portions are formed on one side of the substrate in the width direction.

5. The substrate for a display according to claim 1, wherein, The hinge portion is formed by passing through one surface and another surface of a unidirectional region in the end region of the substrate.

6. The substrate for a display according to claim 1, wherein, The hinge portion overlaps with the column in which the first through hole is formed in the width direction of the substrate.

7. The substrate for a display according to claim 1, wherein, The hinge portion does not overlap with the column in which the first through hole is formed in the width direction of the substrate.

8. The substrate for a display according to claim 1, wherein, The size of the hinge is the same as the size of the first through hole.

9. The substrate for a display according to claim 1, wherein, The size of the hinge portion is different from the size of the first through hole.

10. The substrate for a display according to claim 1, wherein, The hinge has a curved surface.

11. The substrate for a display according to claim 1, wherein, The shape of the hinge is different from the shape of the first through hole.

12. The substrate for a display according to claim 1, wherein, At maximum height, the distance between the first region and the second region is 0.1 mm to 5 mm.

13. The substrate for a display according to claim 1, wherein, At the minimum height, the distance between the first region and the second region is 0.1 mm to 5 mm.

14. The substrate for a display according to claim 3, wherein, The second region includes multiple variable regions. Among the plurality of variable regions, the size of the second through hole's second-1 opening region gradually decreases as it extends along the direction of the first region.

15. The substrate for a display according to claim 1, wherein, The curvature of the second region is greater than that of the first region.

16. The substrate for a display according to claim 1, wherein, The surface roughness of the first region is less than that of the second region.

17. The substrate for a display according to claim 1, wherein, The other surface is folded so that they face each other. The size of the second-2nd opening region in the variable region is larger than the size of the second-1st opening region in the variable region.

18. The substrate for a display according to claim 3, wherein, Each of the plurality of first through holes includes a first-1 opening region of one surface opening and a first-2 opening region of the other surface opening. The sizes of the first-1 opening region and the first-2 opening region are the same as the sizes of the second-2 opening region in the variable region, the second-1 opening region in the fixed region, and the second-2 opening region in the fixed region.

19. The substrate for a display according to claim 1, wherein, The first region is folded by a folding axis. The folding shaft overlaps with the column having the first through hole.

20. A flexible display device, comprising: Substrate for displays; Display panel, the display panel being disposed above the substrate for the display; as well as A touch panel is disposed on the display panel. The substrate for the display includes the substrate for the display as described in any one of claims 1 to 19.

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