A flexible display panel and display device

Abstract

The present disclosure provides a flexible display panel and a display device, the flexible display panel having a display area, a binding area and a bending area; the flexible display panel comprises: a flexible substrate; a back film, the back film is provided with a groove, the groove is located between the display area and the binding area, the edge of the groove defines the bending area, the bending area comprises: a first boundary adjacent to the display area; a second boundary adjacent to the binding area; opposite first and second edges extending from the display area to the binding area; a protective glue, at least comprising: a first coverage area located on the second surface and covering the bending area; a second coverage area extending from the first coverage area to the first edge and covering at least part of the area of the first surface; a third coverage area extending from the first coverage area to the second edge and covering at least part of the area of the second surface. The flexible display panel and the display device of the present disclosure can improve the fracture problem of the flexible display panel Pad Bending area.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more particularly to a flexible display panel and display device. Background Technology

[0002] With the development of self-emissive display technologies, such as OLED (Organic Light-Emitting Diode) display panels, QLED (Quantum Dot Light-Emitting Diodes) display panels, and Micro LED (Micro Light-Emitting Diodes) display panels, they have become research hotspots due to their good flexibility, high contrast, and thinner and lighter characteristics. In particular, flexible display panels are being increasingly used in various fields. Summary of the Invention

[0003] This disclosure provides a flexible display panel and display device that can improve the breakage problem of the Pad Bending area in flexible display panels in related technologies.

[0004] The technical solutions provided in this disclosure are as follows:

[0005] This disclosure provides a flexible display panel having a display area, a bonding area, and a bending area located between the display area and the bonding area. The display area includes a first side, and the bonding area and the bending area are located on the first side. The flexible display panel includes:

[0006] A flexible substrate, the flexible substrate comprising opposing first and second surfaces;

[0007] A back film is disposed on a first surface of the flexible substrate. The back film has a groove located between the display area and the bonding area. The edge of the groove defines a bending area. The bending area includes: a first boundary adjacent to the display area; a second boundary adjacent to the bonding area; and opposing first and second edges extending from the display area to the bonding area.

[0008] And, a protective adhesive, the protective adhesive comprising at least: a first covering area, the first covering area being located on the second surface and covering the bending area; a second covering area, the second covering area extending from the first covering area toward the first edge and at least covering a portion of the first surface; and a third covering area, the third covering area extending from the first covering area toward the second edge and at least covering a portion of the second surface.

[0009] For example, the range of values ​​for the length H1 of the second coverage area in the first direction is:

[0010] 0 < H1 ≤ 1 / 2B,

[0011] Wherein, B is the length of the bending region in the first direction, and the first direction is a direction perpendicular to the first edge and parallel to the substrate.

[0012] For example, the length H2 of the third coverage area in the first direction has the following range:

[0013] 0 < H2 ≤ 1 / 2B

[0014] Wherein, B is the length of the bending region in the first direction, and the first direction is a direction perpendicular to the first edge and parallel to the substrate.

[0015] For example, the protective adhesive further includes:

[0016] A fourth coverage area is formed by the first coverage area extending from the first boundary toward the display area.

[0017] For example, the display area includes a second side adjacent to the first side and a third side disposed opposite to the second side;

[0018] The range of values ​​for the length L of the fourth coverage area in the first direction is:

[0019] L = B + K1 + K2;

[0020] Wherein, B is the length of the bending area in the first direction, and the first direction is a direction perpendicular to the first edge and parallel to the substrate;

[0021] 0 < K1 ≤ K1', where K1' is the straight-line distance from the first edge to the second side edge in the first direction;

[0022] 0 < K2 ≤ K2', where K2' is the straight-line distance from the second edge to the third side edge in the first direction.

[0023] For example, the flexible display panel includes a polarizer coverage area for covering a polarizer;

[0024] The range of values ​​for the width E of the fourth coverage area in the second direction is:

[0025] 0 < E ≤ N;

[0026] Wherein, N is the width of the polarizer-covered area from the edge to the first boundary in a second direction, the second direction being perpendicular to the first boundary and parallel to the flexible substrate.

[0027] For example, the protective adhesive further includes:

[0028] The fifth coverage area is formed by the first coverage area extending from the second boundary toward the location of the binding area.

[0029] For example, the bonding area is provided with a driver IC;

[0030] The range of values ​​for the width C of the fifth coverage area in the second direction is:

[0031] 0 < C ≤ M;

[0032] M is the straight-line distance from the second boundary to the driving IC in the second direction, which is perpendicular to the second boundary and parallel to the flexible substrate.

[0033] For example, the thickness F of the protective adhesive film in the direction perpendicular to the flexible substrate ranges as follows:

[0034] 0 < F ≤ T,

[0035] T is the sum of the film thicknesses of the polarizer and optical adhesive layer disposed on the flexible display panel in the direction perpendicular to the flexible substrate.

[0036] This disclosure also provides a display device, including the flexible display panel described above.

[0037] The beneficial effects of the embodiments disclosed herein are as follows:

[0038] The flexible display panel and display device provided in this disclosure improve the way the protective adhesive (e.g., MCL adhesive) is covered on the PadBending area of ​​the flexible display panel, so that the protective adhesive can effectively protect the entire bending area, alleviate the external force caused by collisions in the bending area during production, transportation, customer installation, etc., and thus solve the problem of bending area breakage. Attached Figure Description

[0039] Figure 1 This is a front view of the flexible display panel before pad bending is performed in some embodiments provided in this disclosure;

[0040] Figure 2 This disclosure describes flexible display panels in some embodiments. Figure 1 Rear view;

[0041] Figure 3 This indicates a flexible display panel in other embodiments of the present disclosure. Figure 1 Rear view;

[0042] Figure 4 express Figure 1 Side view;

[0043] Figure 5 express Figure 4 A schematic diagram of the flexible display panel in the process of pad bending;

[0044] Figure 6 express Figure 1 A bottom view of the protective adhesive in a flexible display panel. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0046] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0047] Before providing a detailed description of the flexible display panel and display device provided in the embodiments of this disclosure, it is necessary to explain the related technologies as follows:

[0048] As consumers' demands for electronic products increase, flexible OLED screens have emerged as a necessary technology. In the manufacturing process of flexible screens, pad bending technology, due to its ability to significantly shorten the bezel width of the display panel, has gradually replaced COF bending technology and become the mainstream bending technology. Pad bending technology requires bending the pad area to the back of the display panel to reduce the bezel width. During pad bending, thinning processes such as removing the back film are required in the bent area, which makes the pad bending increasingly fragile and prone to cracking.

[0049] The conventional practice to protect the bending area is to apply MCL (Metal Cover Layer) adhesive to the bending area before pad bending. However, MCL adhesive cannot cover the entire bending area. During production, transportation, and customer assembly, the pad bending may be subjected to impacts, resulting in cracks and causing display problems.

[0050] To address the aforementioned issues, this disclosure provides a flexible display panel and display device. By improving the way the protective adhesive (e.g., MCL adhesive) covers the Pad Bending area of ​​the flexible display panel, the protective adhesive can effectively protect the entire bending area, mitigating the external forces caused by collisions during production, transportation, and customer installation, thereby solving problems such as bending area breakage.

[0051] like Figure 1 As shown, the flexible display panel 100 provided in this embodiment of the present disclosure has a display area A and a peripheral area disposed around the display area A. The peripheral area is used for routing traces, such as gate driving circuits.

[0052] The display area A is provided with a plurality of display pixels, for example, a plurality of display pixels arranged in an array, and the display area A is also provided with a pixel driving circuit for driving the display pixels to perform display.

[0053] In some embodiments, the display area A of the flexible display panel 100 includes four sides, such as a first side A1, a second side A2 adjacent to the first side A1, a third side A3 opposite to the second side A2, and a fourth side A4 opposite to the first side A1.

[0054] The surrounding area can be further divided into a binding area S1 and a bending area S2 (Pad Bending), with the bending area S2 located between the binding area S1 and the display area A.

[0055] In some embodiments, both the bonding area S1 and the bending area S2 are disposed on one side of the display area A, for example, on the first side A1 of the display area A. For example, taking the flexible display panel 100 as an example applied to a display device such as a mobile phone, the first side A1 can be the lower side. Figures 1 to 6 As shown, the flexible display panel 100 includes not only the display area A and the peripheral area, but also a flexible substrate, a back film, and a protective adhesive 10.

[0056] The flexible substrate includes a first surface (i.e., the front side) and a second surface (i.e., the back side). A back film is disposed on the first surface of the flexible substrate. The back film has a groove located between the display area A and the bonding area S1. The edge of the groove defines the bending area S2. Figure 1 The dashed line shown in the diagram represents the grooved area on the back membrane, i.e., the bending area S2.

[0057] The edge of the bending area S2 can be divided into: a first boundary 10c adjacent to the display area A; a second boundary 10d adjacent to the binding area S1; and opposing first edges 10a and second edges 10b extending from the display area A to the binding area S1.

[0058] It should be noted that in some embodiments, such as Figure 3 As shown, the binding area S1 and the bending area S2 can be integrally connected; in other embodiments, such as Figure 2 As shown, the bonding area S1 and the bending area S2 can also be a non-integrated structure. The protective adhesive 10 is mainly used to protect the bending area S2, and it can be, but is not limited to, MCL adhesive (Metal Cover Layer).

[0059] The protective adhesive 10 includes at least:

[0060] A first coverage area 11 is located on the second surface and covers the bending area S2;

[0061] The second covering area 12 extends from the first covering area 11 toward the first edge 10a and at least covers a portion of the first surface.

[0062] The third covering area 13 extends from the first covering area 11 toward the second edge 10b and at least covers a portion of the second surface.

[0063] In other words, the protective adhesive 10 at least completely covers the front side (first surface) of the bending area S2, and the protective adhesive 10 also extends from the front side from the first edge 10a and the second edge 10b to the back side of the bending area S2, respectively, wrapping the first edge 10a and the second edge 10b of the bending area S2, and partially covering the back side of the bending area S2.

[0064] Analysis of the fracture problem in the bending zone S2 revealed that the areas most prone to fracture due to external forces from collisions are the first edge 10a and the second edge 10b of the bending zone S2. Therefore, the above-mentioned solution involves wrapping the first edge 10a and the second edge 10b of the bending zone S2 with the protective adhesive 10, and at least partially covering the back surface of the bending zone S2. This ensures that the protective adhesive 10 not only completely covers the bending zone S2 but also effectively covers its edges, thereby better protecting the entire bending zone S2 and mitigating the external forces caused by collisions during production, transportation, and customer installation, thus solving the problem of fracture in the bending zone S2.

[0065] Regarding the coverage area of ​​the protective adhesive 10 on the back side of the bending area S2, in some embodiments of this disclosure, such as... Figure 1 , Figure 2 and Figure 6 As shown, the length H1 of the second covering area 12 in the first direction has a range of 0 < H1 ≤ 1 / 2B, where B is the length of the bending area S2 in the first direction, and the first direction is the direction perpendicular to the first edge 10a and parallel to the substrate.

[0066] The length H2 of the third coverage area 13 in the first direction ranges from 0 to H2.

[0067] ≤1 / 2B, where B is the length of the bending region S2 in the first direction, which is a direction perpendicular to the first edge 10a and parallel to the substrate.

[0068] In the above scheme, the sum of the length H1 of the second covering area 12 in the first direction and the length H2 of the third covering area 13 in the first direction can be less than or equal to the length B of the bending area S2 in the first direction. That is, the protective adhesive 10 can completely cover the bending area S2 on the back side of the bending area S2, or it can only cover a portion of the bending area S2.

[0069] Furthermore, the length H1 of the second covering area 12 in the first direction and the length H2 of the third covering area 13 in the first direction may be equal or unequal. For example, H1 = H2 = 5.0 mm.

[0070] In some exemplary embodiments, such as Figure 2 and Figure 3 As shown, one edge of the second covering area 12 and the third covering area can be flush with the first boundary 10c, and the other edge can be flush with the second boundary 10d. That is, the width D1 of the second covering area 12 in the second direction is D1 = D, and the width D1 of the third covering area 13 in the second direction is D1 = D. The second direction is perpendicular to the first boundary 10c and parallel to the flexible substrate. D is the width of the bending area S2 in the second direction. The value of D is related to the value of the bending radius R of the bending area S2. D ≥ 3.14 * R, where R is the bending radius of the bending area S2. Its value is related to the overall design of the flexible display panel 100. For example, the value of R is 0.25 mm or 0.3 mm.

[0071] It should be noted that the above is only an example. In other embodiments, the two side edges of the second covering area 12 and the third covering area 13 may not be flush with the first boundary 10c and the second boundary 10d.

[0072] In addition, such as Figure 2 and Figure 3 As shown, in some embodiments, the edges of the second covering area 12 and the third covering area 13 are straight edges. This is only for illustration; in practical applications, the edges of the second covering area 12 and the third covering area 13 are not limited to straight edges. That is, the shape of the second covering area 12 and the third covering area 13 is not limited; they can be regular or irregular shapes. Furthermore, in some embodiments, such as... Figure 1 As shown, the protective adhesive 10 further includes a fourth covering area 14, which is formed by the first covering area 11 extending from the first boundary 10c toward the display area A.

[0073] In the above solution, the protective adhesive 10, on the front side of the flexible substrate, not only completely covers the bending area S2, but also extends at least a portion toward the direction of the display area A, and overlaps the lower border area between the display area A and the bending area S2, so as to further and better protect the bending area S2.

[0074] The length L of the fourth covering area 14 in the first direction is in the range of: L = B + K1 + K2; where B is the length of the bending area S2 in the first direction, the first direction being perpendicular to the first edge 10a and parallel to the substrate; 0 < K1 ≤ K1', K1' being the straight-line distance from the first edge 10a to the edge of the second side A2 in the first direction; 0 < K2 ≤ K2', K2' being the straight-line distance from the second edge 10b to the edge of the third side A3 in the first direction.

[0075] Furthermore, in some embodiments, the flexible display panel 100 includes a polarizer 30 covering area for covering the polarizer 30; the width E of the fourth covering area 14 in the second direction is in the range of 0 < E ≤ N; where N is the width from the edge of the polarizer 30 covering area to the first boundary 10c in the second direction, and the second direction is perpendicular to the first boundary 10c and parallel to the flexible substrate.

[0076] In other words, when the protective adhesive 10 is applied, it extends in the direction of the display area A to be flush with the edge of the polarizer 30 on the flexible display panel 100. The specific data depends on the distance between the polarizer 30 and the bottom side of the flexible display panel 100 in the display device, for example, E = 0.45 mm.

[0077] Furthermore, in some embodiments, such as Figure 1 As shown, the protective adhesive 10 further includes a fifth covering area 15, which is formed by the first covering area 11 extending from the second boundary 10d in the direction of the bonding area S1.

[0078] In the above scheme, the protective adhesive 10, on the front side of the flexible substrate, not only completely covers the bending area S2, but also extends at least a portion toward the direction of the bonding area S1, and overlaps the area between the bonding area S1 and the bending area S2, so as to further and better protect the bending area S2.

[0079] In some embodiments, such as Figure 1 As shown, the bonding area S1 can be equipped with a driver IC 20; the width C of the fifth covering area 15 in the second direction has a range of 0 < C ≤ M; M is the straight-line distance from the second boundary 10d to the driver IC 20 in the second direction, and the second direction is perpendicular to the second boundary 10d and parallel to the flexible substrate.

[0080] In other words, when the protective adhesive 10 is applied, it extends in the direction of the bonding area S1 to be flush with the edge of the driving IC 20 at most, for example, C = 0.45 mm.

[0081] It should be noted here that... Figure 1 In the illustrated embodiment, the bonding area S1 may be provided with a driver IC 20. In other embodiments, the bonding area S1 may not be provided with a driver IC. In this case, the width C of the fifth coverage area 15 in the second direction may be limited by the driver IC. Furthermore, the film thickness F of the protective adhesive 10 in the direction perpendicular to the flexible substrate is related to the dispensing process. The value of F ranges from 0 to E to T, where T is the sum of the film thicknesses of the polarizer 30 and the optical adhesive layer 40 disposed on the flexible display panel 100 in the direction perpendicular to the flexible substrate. For example, T = 0.09 mm.

[0082] In addition, such as Figure 1 As shown, D is the width of the bending area S2 in the second direction. The value of D is related to the value of the bending radius R of the bending area S2. D≥3.14*R, where R is the bending radius of the bending area S2. Its value is related to the overall design of the flexible display panel 100. For example, the value of R is 0.25mm or 0.3mm.

[0083] In conjunction with the above, in the flexible display panel 100 provided in this embodiment, the total amount of protective adhesive 10 applied is A≈B*(C+D)*F+E*F*(K1+B+K2)+D*(H1+H2)*F. It should be noted that in the flexible display panel 100 provided in this embodiment, the protective adhesive 10 can be formed using a coating process, and the coating edge of the protective adhesive can be sloped, for example, as... Figure 6 As shown, the edges of the second coverage area 12 and the third coverage area 13 can be sloped (e.g., Figure 6 (As shown in dashed boxes O and P).

[0084] Furthermore, this disclosure also provides a display device, including the flexible display panel 100 provided in this disclosure embodiment. This display device can be various display devices such as mobile phones, tablets, laptops, and in-vehicle computers.

[0085] The following points need to be explained:

[0086] (1) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure. Other structures can be referred to the general design.

[0087] (2) For clarity, the thickness of layers or regions is enlarged or reduced in the drawings used to describe embodiments of the present disclosure, i.e., these drawings are not drawn to actual scale. It will be understood that when an element such as a layer, film, region or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element or there may be intermediate elements.

[0088] (3) Where there is no conflict, the embodiments of this disclosure and the features in the embodiments can be combined with each other to obtain new embodiments.

[0089] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. The scope of protection of this disclosure shall be determined by the scope of the claims.

Claims

1. A flexible display panel having a display area, a bonding area, and a bending area located between the display area and the bonding area, the display area including a first side, the bonding area and the bending area being located on the first side; characterized in that, The flexible display panel includes: A flexible substrate, the flexible substrate comprising opposing first and second surfaces; A back film is disposed on a first surface of the flexible substrate. The back film has a groove located between the display area and the bonding area. The edge of the groove defines a bending area. The bending area includes: a first boundary adjacent to the display area; a second boundary adjacent to the bonding area; and opposing first and second edges extending from the display area to the bonding area. And, a protective adhesive, the protective adhesive including a metal overlay, the protective adhesive including at least: a first covering area, the first covering area being located on the second surface and covering the bending area; a second covering area, the second covering area extending from the first covering area toward the first edge and at least covering a portion of the first surface; a third covering area, the third covering area extending from the first covering area toward the second edge and at least covering a portion of the second surface; the coating edge of the protective adhesive is sloped.

2. The flexible display panel according to claim 1, characterized in that, The range of values ​​for the length H1 of the second coverage area in the first direction is: 0 < H1 ≤ 1 / 2B, Wherein, B is the length of the bending region in the first direction, and the first direction is a direction perpendicular to the first edge and parallel to the substrate.

3. The flexible display panel according to claim 1, characterized in that, The range of values ​​for the length H2 of the third coverage area in the first direction is: 0 < H2 ≤ 1 / 2B Wherein, B is the length of the bending region in the first direction, and the first direction is a direction perpendicular to the first edge and parallel to the substrate.

4. The flexible display panel according to claim 1, characterized in that, The protective adhesive also includes: A fourth coverage area is formed by the first coverage area extending from the first boundary toward the display area.

5. The flexible display panel according to claim 4, characterized in that, The display area includes a second side adjacent to the first side and a third side opposite to the second side; The range of values ​​for the length L of the fourth coverage area in the first direction is: L = B + K1 + K2; Wherein, B is the length of the bending area in the first direction, and the first direction is a direction perpendicular to the first edge and parallel to the substrate; 0 < K1 ≤ K1', where K1' is the straight-line distance from the first edge to the second side edge in the first direction; 0 < K2 ≤ K2', where K2' is the straight-line distance from the second edge to the third side edge in the first direction.

6. The flexible display panel according to claim 4, characterized in that, The flexible display panel includes a polarizer coverage area for covering a polarizer; The range of values ​​for the width E of the fourth coverage area in the second direction is: 0 < E ≤ N; Wherein, N is the width of the polarizer-covered area from the edge to the first boundary in a second direction, the second direction being perpendicular to the first boundary and parallel to the flexible substrate.

7. The flexible display panel according to claim 1, characterized in that, The protective adhesive also includes: The fifth coverage area is formed by the first coverage area extending from the second boundary toward the location of the binding area.

8. The flexible display panel according to claim 7, characterized in that, The binding area is equipped with a driver IC; The range of values ​​for the width C of the fifth coverage area in the second direction is: 0 < C ≤ M; M is the straight-line distance from the second boundary to the driving IC in the second direction, which is perpendicular to the second boundary and parallel to the flexible substrate.

9. The flexible display panel according to claim 1, characterized in that, The range of values ​​for the film thickness F of the protective adhesive in the direction perpendicular to the flexible substrate is as follows: 0 < F ≤ T, T is the sum of the film thicknesses of the polarizer and optical adhesive layer disposed on the flexible display panel in the direction perpendicular to the flexible substrate.

10. A display device, characterized in that, Including the flexible display panel as described in any one of claims 1 to 9.

Images