A display panel

Abstract

The embodiment of the application discloses a display panel, which comprises at least one bending area and plane areas located on both sides of the bending area, further comprises a back plate body, a back plate support arranged on one side surface of the back plate body, and a bonding layer arranged between the back plate body and the back plate support, wherein the bonding layer is only located in the plane area; a groove is arranged on the side surface of the back plate body close to the back plate support and / or the side surface of the back plate support close to the back plate body, the groove is located at the edge of the plane area close to the bending area, and the bonding layer fills the groove. The display panel provided by the embodiment of the application removes the bonding layer in the bending area, reduces the thickness of the bending area of the display panel, increases the thickness of one end of the bonding layer close to the bending area to resist the shear stress when the display panel is bent, and avoids the problem of delamination of the bonding layer when the display panel is bent.

Description

Technical Field

[0001] This application relates to the field of backplanes, specifically to a display panel. Background Technology

[0002] With the continuous deepening and breakthroughs in flexible OLED technology research, a complete industrial layout has been formed globally, and foldable phones are increasingly favored by consumers. Foldable phones are bound to be the mainstream products in the future mobile phone market. Relying on the superior performance of OLED, terminal display products, such as mobile phones and laptops, are gradually becoming thinner and lighter. Against this backdrop, improving the production yield and reliability of OLED modules is one of the key technological challenges at this stage. To improve the production yield of OLED modules, it is essential to control and design the bending stress of foldable screens. The most effective methods are usually to reduce the thickness of the thin film layer and improve the stacking design.

[0003] To minimize bending stress in the module, the adhesive layer between the OLED module's backplate and its support is typically designed in segments. This means that the bending area, located one layer below the backplate, is not covered with adhesive. The purpose is to disconnect the backplate and support in the thickness direction, thereby reducing the module's thickness at the bending area and thus decreasing bending stress. However, as... Figure 1 As shown, because the adhesive layer at the bending area is broken, if the thickness is too thin or the adhesion to the upper and lower film layers is insufficient, module detachment will occur at the left and right positions of the segmented adhesive, gradually leading to bubble formation. In other words, the adhesive layer near the bending area experiences localized discontinuity or excessive stress during the module bending process, resulting in adhesive overflow or detachment, which is the main cause of bubble formation. This phenomenon directly affects the production yield of foldable screens. Therefore, while using thinner OLED modules to reduce bending stress, it is also necessary to consider how to effectively prevent detachment of the segmented adhesive. Summary of the Invention

[0004] This application provides a display panel that can solve the technical problem in the prior art where the display panel is prone to delamination at the edge of the bending area.

[0005] This application provides a display panel including at least one bending area and planar areas located on both sides of the bending area, and also includes a back panel body; a back panel support member disposed on one side surface of the back panel body; and an adhesive layer disposed between the back panel body and the back panel support member, the adhesive layer being located only in the planar areas; a groove is provided on the side surface of the back panel body near the back panel support member and / or on the side surface of the back panel support member near the back panel body, the groove being located at the edge of the planar areas near the bending area, and the adhesive layer filling the groove.

[0006] Optionally, in some embodiments of the present application, the adhesive layer comprises a first adhesive layer arranged between the backplate body and the backplate support; and a second adhesive layer arranged in the groove, the second adhesive layer being bonded to the first adhesive layer, wherein a side edge of the second adhesive layer is aligned with a side edge of the first adhesive layer.

[0007] Optionally, in some embodiments of the present application, a ratio of a distance between the grooves on two sides of the bending area to the width of the bending area is greater than 1.1 and less than 1.25.

[0008] Optionally, in some embodiments of the present application, a ratio of the width of the groove to the width of the bending area is greater than 0.16 and less than 0.25.

[0009] Optionally, in some embodiments of the present application, an opening area of the groove is less than a bottom area of the groove.

[0010] Optionally, in some embodiments of the present application, a side edge of the groove close to the bending area is in a wavy structure or a zigzag structure.

[0011] Optionally, in some embodiments of the present application, the groove units are arranged at equal distances along an edge of the flat area close to the bending area.

[0012] Optionally, in some embodiments of the present application, an opening shape of the groove unit is circular, rectangular, diamond-shaped or trapezoidal.

[0013] Optionally, in some embodiments of the present application, the backplate support is provided with at least one stress release structure, the stress release structure being located in the bending area, when the display panel is bent, a side of the stress release structure away from the backplate body is in an expanded state, and a side of the stress release structure close to the backplate body is in a contracted state.

[0014] Optionally, in some embodiments of the present application, the stress release structure comprises a plurality of long-strip-shaped through holes, the long-strip-shaped through holes being distributed in a staggered manner or in an array manner; the long-strip-shaped through hole comprises two opposite long sides, the long sides being perpendicular to a bending direction of the backplate support.

[0015] The display panel of the present embodiment has the advantages that the adhesive layer of the bending area is removed, the thickness of the bending area of the display panel is reduced, the shear stress when the display panel is bent is resisted by increasing the thickness of the adhesive layer close to one end of the bending area, and the problem of adhesive layer delamination when bent is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort based on these drawings.

[0017] Figure 1 is a structural schematic diagram of a display panel in the background art;

[0018] Figure 2 is a structural schematic diagram of a display panel provided by the embodiments of the present application;

[0019] Figure 3 is a structural schematic diagram of a display panel after bending provided by the embodiments of the present application;

[0020] Figure 4 is a broken line graph of the risk value of the adhesive layer fracture and the groove width provided by the embodiments of the present application;

[0021] Figure 5 is a side view of the back plate body and the back plate support provided by the embodiments of the present application;

[0022] Figure 6 is a side view of the back plate body and the back plate support provided by another preferred embodiment of the present application;

[0023] Figure 7 is a plan view of the back plate support provided by the embodiments of the present application;

[0024] Figure 8 is a plan view of the back plate support provided by another preferred embodiment of the present application;

[0025] Figure 9 is a plan view of the back plate support provided by another preferred embodiment of the present application.

[0026] Explanation of reference signs:

[0027] Display panel 1;

[0028] Back plate body 100; back plate support 200;

[0029] Adhesive layer 300; panel body 400;

[0030] Bending area 101; planar area 102;

[0031] Groove 210; first adhesive layer 310;

[0032] Second adhesive layer 320; groove unit 211;

[0033] Stress relief structure 220; Elongated through hole 221;

[0034] First blind hole 222; Second blind hole 223. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0036] This application provides a display panel. The details are as follows.

[0037] Example

[0038] This embodiment is mainly used to explain the display panel 1 of the present invention, such as Figure 2 and Figure 3 As shown, the display panel 1 includes a back plate body 100, a back plate support 200, an adhesive layer 300, and a panel body 400. In this embodiment, the display panel 1 is a foldable display panel. The display panel 1 includes a light-emitting surface, which is located on the side of the panel body 400 away from the back plate body 100. When not in use, the light-emitting surface of the display panel 1 is bent inward to achieve the purpose of folding the display panel 1, which not only protects the display panel 1 from being scratched by foreign objects, but also reduces the volume of the display panel 1.

[0039] The back panel body 100 and the back panel support 200 are bonded together by an adhesive layer 300. The back panel support 200 is located on the side of the back panel body 100 away from the light-emitting surface. When the display panel 1 is bent, the bending deformation of the back panel support 200 is large, and the bending stress it is subjected to is large. In order to improve the service life of the back panel support 200, the back panel support 200 in this embodiment is a high-strength thin steel plate containing manganese, with a single yield strength of not less than 1600 MPa, and has good toughness and strength.

[0040] According to the folding requirement of the display panel 1, the display panel 1 is divided into a bending area 101 and a planar area 102, the planar area 102 is arranged on both sides of the bending area 101, in the embodiment, the display panel 1 is a single folding panel, that is, the display panel 1 in the embodiment includes one bending area 101, in other preferred embodiments of the application, the display panel 1 can include N bending areas 101 (N is a natural number greater than 1), and the number of corresponding planar areas 102 is N+1. In order to reduce the bending stress of the display panel 1, the bonding layer 300 in the bending area 101 is usually removed to reduce the thickness of the bending area 101, thereby effectively reducing the bending stress of the display panel 1 at the bending area 101, and the removed bonding layer 300 is symmetrical about the bending center line of the bending area 101, so as to avoid that the asymmetric bonding layer 300 affects the bending of the display panel 1.

[0041] The adhesive layer 300 is an optical adhesive (OCA) material, which has the technical effects of colorless transparency, high light transmittance, high adhesive strength, and small curing shrinkage. The adhesive layer 300 is located in the planar region 102 and is used to bond the back plate body 100 and the back plate support 200. When the display panel 1 is bent, the side of the adhesive layer 300 close to the bending region 101 is prone to falling off under the action of tensile stress because the adhesive layer 300 is designed to be disconnected. Moreover, the bending direction of the display panel 1 in the embodiment is the direction in which the back plate body 100 moves away from the back plate support 200, so that the adhesive force between the adhesive layer 300 and the back plate support 200 decreases with the increase of the number of bending and the bending time. In the embodiment, the groove 210 is etched on the back plate support 200 by a half-etching process, which is used to fill the adhesive layer 300, increase the contact area between the adhesive layer 300 and the back plate support 200, increase the adhesive force between the adhesive layer 300 and the back plate support 200, and increase the overall thickness of the adhesive layer 300 at the edge of the bending region 101, thereby effectively resisting the shear stress of the adhesive layer 300 when the display panel 1 is bent. The shear stress is the in-plane force per unit area of the adhesive layer 300 in the shear cross section when the display panel 1 is bent. The shear cross section is the longitudinal cross section of the adhesive layer 300 between the back plate support 200 and the back plate body 100. Because the size of the shear stress is negatively correlated with the area of the shear cross section, the larger the shear cross section, that is, the thicker the adhesive layer 300, the smaller the shear stress, so that the adhesive force of the adhesive layer 300 can be greater than or offset the shear force, thereby effectively avoiding the technical problem of the adhesive layer 300 falling off due to insufficient adhesive force between the adhesive layer 300 and the back plate support 200 when the display panel 1 is bent, and avoiding the technical problem of bulging or bubbling at the edge of the bending region 101 of the display panel 1. In another preferred embodiment of the present application, a groove can also be etched on the back plate body 100 by a half-etching process. The groove on the back plate support 200 and the groove on the back plate body 100 can be selected or can exist at the same time, and the purpose is also to increase the thickness of the adhesive layer 300 and effectively resist the shear stress generated when the display panel 1 is bent.

[0042] The grooves 210 are located at the two side edges of the bending area 101, and the ratio of the interval between the grooves 210 on the same side of the bending area 101 to the width of the bending area 101 is 1.1-1.25, so as to avoid the overflow of the adhesive layer 300 inside the groove 210 to the bending area 101 under stress. Since the width and depth of the groove 210 determine the size of the shear stress that the adhesive layer 300 can resist at the edge of the bending area 101, the narrower the width and the shallower the depth of the groove 210, the smaller the shear stress that the adhesive layer 300 can resist. Through mechanical simulation, it can be known that the optimal values of the width and the depth of the groove 210. According to the analysis of the test results, when the width N of the groove 210 is 0.8-1.6 mm, the stress value of the adhesive layer 300 is less than the safety reference value (risk value 0.237 MPa).

[0043] As shown in Figure 4 , Figure 4 The data is from a mechanical simulation test. As can be seen from the figure, when the groove width is 1-1.5 mm, the stress value of the adhesive layer 300 will decrease rapidly until it is lower than the safety reference value. When the width of the groove is greater than 1.7 mm, the stress value of the adhesive layer 300 will tend to be stable, and the stress value will be stable at 0.15-0.2 MPa.

[0044] Through multiple mechanical simulation tests, the results show that when the width of the groove 210 is greater than 2 mm, the stress value of the adhesive layer 300 will be stable and lower than the safety reference value, which proves that the risk is significantly reduced and tends to be stable. In order to avoid the excessive width N of the groove 210 leading to the reduction of the bending stiffness of the backboard support 200, in the embodiment, the width N of the groove 210 is 2-4 mm. The ratio of the width of the groove 210 to the width of the bending area 101 is greater than 0.16 and less than 0.25, and at the same time, the depth of the groove 210 is 0.15-0.3 times the thickness of the backboard support 200, so as to avoid the excessive depth of the groove 210 leading to the reduction of the bending stiffness of the backboard support 200.

[0045] As shown in Figure 5 and Figure 6As shown, the bonding layer 300 includes a first bonding layer 310 and a second bonding layer 320, wherein the first bonding layer 310 is arranged between the back plate body 100 and the back plate support 200, and the second bonding layer 320 is filled in the groove 210 through coating, planar processing or other processes. When the second bonding layer 320 completely fills the groove 210, the upper surface of the second bonding layer 320 protrudes out of the groove 210 or is flush with the opening surface of the groove 210, so as to facilitate bonding of the second bonding layer 320 and the first bonding layer 310. The bonding force between the first bonding layer 310 and the second bonding layer 320 is almost equal to the polymerization force inside the first bonding layer 310 or the second bonding layer 320, so that the first bonding layer 310 and the second bonding layer 320 are bonded as an integrated structure. The side edge of the first bonding layer 310 close to the bending area 101 is aligned with the side edge of the second bonding layer 320 close to the bending area 101. In order to avoid overflow of the bonding layer 300 in the direction of the bending area 101 under the action of bending stress when the display panel 1 is bent, in the embodiment, the ratio of the gap distance of the bonding layer 300, i.e. the gap between the bonding layers 300 on both sides of the bending area 101, to the width of the bending area 101 is 1.1-1.25, i.e. a certain buffer gap is arranged between the bonding layer 300 and the bending area 101, so as to avoid overflow of the bonding layer 300 due to excessive stress.

[0046] In the embodiment, as shown in Figure 7 The groove 210 extends up and down along the bending center line of the bending area 101 to the edge of the back plate support 200, and the opening shape is a long rectangular shape. In another preferred embodiment of the present application, as shown in Figure 8 The side edge of the groove 210 close to the bending area 101 is in a wavy or zigzag shape. The zigzag or wavy line increases the length of the edge of the groove 210 close to the bending area 101, increases the contact area of the edge of the bonding layer 300 with the back plate body 100 and the back plate support 200, and avoids separation of the edge of the bonding layer 300 from the back plate body or the back plate support 200 when bending. In another preferred embodiment of the present application, as shown in Figure 9 The groove units 211 are arranged at intervals, which effectively ensures the rigidity of the back plate support 200 on the premise of increasing the thickness of the bonding layer 300. The opening shape of the groove unit 211 is a trapezoidal shape, a rhombus shape, a polygonal structure with an arc-shaped side close to the bending area 101, etc.

[0047] In particular, in order to avoid the technical problem that the second bonding layer 320 is separated from the bottom of the groove 210 under the action of the bending stress, thereby causing the second bonding layer 320 to fall off, in the embodiment, the groove 210 is arranged in a structure of being narrow at the top and wide at the bottom, that is, the opening area of the groove 210 is smaller than the bottom area of the groove 210. In another preferred embodiment of the present application, the side wall of the groove 210 can also be outwardly concave to form a “pot” shape, which can also achieve the technical purpose of limiting the relative position of the second bonding layer 320 and the groove 210.

[0048] Since the bending deformation of the back plate support 200 is relatively large when the display panel 1 is bent, in order to further reduce the bending stress of the back plate support 200, in the embodiment, a stress release structure 220 is arranged at the bending area 101 corresponding to the back plate support 200. The stress release structure 220 is a hollow structure. When the display panel 1 is bent, one end of the stress release structure 220 away from the back plate body 100 is in an expanded state, thereby releasing the tensile stress on the side of the back plate support 200 away from the back plate body 100. The other end of the stress release structure 220 close to the back plate body 100 is in a contracted state, thereby releasing the contraction stress on the side of the back plate support 200 close to the back plate body 100.

[0049] Specifically, in the embodiment, the stress release structure 220 is a plurality of arrayed long strip-shaped through holes 221, as shown in FIGS. 2B and 2C, the long edge direction of the long strip-shaped through hole 221 is perpendicular to the bending direction of the display panel 1, that is, the long edge direction of the long strip-shaped through hole 221 is parallel to the arrangement or the extension direction of the two ends of the groove 210. One end or both ends of the long strip-shaped through hole 221 are respectively arranged between another two long strip-shaped through holes, thereby improving the uniformity of the stress release structure 220 and ensuring that the stress on the back plate support 200 can be uniformly released. In another preferred embodiment of the present application, the long strip-shaped through holes 221 can also be distributed in a staggered manner. Figure 5 Figure 7 In another preferred embodiment of the present application, the stress release structure 220 is a plurality of spaced blind holes, as shown in FIG. 2D, the blind hole includes a first blind hole 222 and a second blind hole 223. The first blind hole 222 is located on the side surface of the back plate support 200 facing the back plate body 100, and the second blind hole 223 is located on the side surface of the back plate support 200 away from the back plate body 100. The first blind hole 222 and the second blind hole 223 are arranged in a staggered manner in the direction perpendicular to the back plate support 200, so as to ensure the rigidity of the back plate support 200 and avoid the technical problem of breaking when bending.

[0050] In another preferred embodiment of the present application, the stress release structure 220 is a plurality of spaced blind holes, as shown in FIG. 2D, the blind hole includes a first blind hole 222 and a second blind hole 223. The first blind hole 222 is located on the side surface of the back plate support 200 facing the back plate body 100, and the second blind hole 223 is located on the side surface of the back plate support 200 away from the back plate body 100. The first blind hole 222 and the second blind hole 223 are arranged in a staggered manner in the direction perpendicular to the back plate support 200, so as to ensure the rigidity of the back plate support 200 and avoid the technical problem of breaking when bending. Figure 6

[0051] ​​The display panel provided by the embodiment has the beneficial effects that the display panel provided by the embodiment removes the bonding layer of the bending area, reduces the thickness of the bending area of the display panel, increases the thickness of the bonding layer near one end of the bending area to resist the shear stress when the display panel is bent, and avoids the problem of delamination of the bonding layer when the display panel is bent.

[0052] The display panel provided by the embodiment has the beneficial effects that the display panel provided by the embodiment removes the bonding layer of the bending area, reduces the thickness of the bending area of the display panel, increases the thickness of the bonding layer near one end of the bending area to resist the shear stress when the display panel is bent, and avoids the problem of delamination of the bonding layer when the display panel is bent. The display panel provided by the embodiment has the beneficial effects that the display panel provided by the embodiment removes the bonding layer of the bending area, reduces the thickness of the bending area of the display panel, increases the thickness of the bonding layer near one end of the bending area to resist the shear stress when the display panel is bent, and avoids the problem of delamination of the bonding layer when the display panel is bent.

Claims

1. A display panel, comprising at least a bending area and flat areas on both sides of the bending area, characterized in that, Further comprising a backplate body; a backplate support arranged on one side surface of the backplate body; and a bonding layer arranged between the backplate body and the backplate support, the bonding layer being located only in the planar region; a groove is arranged on the side surface of the backplate body close to the backplate support and / or on the side surface of the backplate support close to the backplate body, the groove being located at the edge of the planar region close to the bending region, and the bonding layer fills the groove.

2. The display panel of claim 1, wherein the bonding layer comprises a first bonding layer arranged between the backplate body and the backplate support; and a second bonding layer filled in the groove, the second bonding layer being bonded with the first bonding layer, wherein one side edge of the second bonding layer is aligned with one side edge of the first bonding layer.

3. The display panel of claim 2, wherein a ratio of a distance between the grooves on both sides of the same bending region to the width of the bending region is greater than 1.1 and less than 1.

25.

4. The display panel of claim 2, wherein a ratio of the width of the groove to the width of the bending region is greater than 0.16 and less than 0.

25.

5. The display panel of claim 1, wherein an opening area of the groove is less than a bottom area of the groove.

6. The display panel of claim 1, wherein a side edge of the groove close to the bending region is a wavy structure or a zigzag structure.

7. The display panel of claim 1, wherein the groove comprises a plurality of groove units, the groove units being distributed at intervals along the edge of the planar region close to the bending region, and a distance between two adjacent groove units is equal.

8. The display panel of claim 7, wherein an opening shape of the groove unit is circular, rectangular, diamond-shaped, or trapezoidal.

9. The display panel of claim 1, wherein the backplate support is provided with at least one stress release structure, the stress release structure being located in the bending region, when the display panel is bent, a side of the stress release structure away from the backplate body is in an expanded state, and a side of the stress release structure close to the backplate body is in a contracted state.

10. The display panel of claim 9, wherein the stress release structure comprises a plurality of long-strip-shaped through holes, the long-strip-shaped through holes being distributed in a staggered manner or in an array manner; the long-strip-shaped through hole comprises two opposite long sides, and the long sides are perpendicular to the bending direction of the backplate support.

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