Flexible display module, preparation method thereof and bending device of flexible display module

Abstract

The application provides a flexible display module, a preparation method thereof, and a bending device of the flexible display module. The flexible display module comprises a flexible display panel, and a first alignment mark and a second alignment mark are arranged on the backlight side of the flexible display panel. A first support layer comprises a first boundary arranged close to a bending area. A second support layer comprises a second boundary arranged close to the bending area. The display area and the bending area are arranged along a first direction. The alignment distance between the second alignment mark and the first alignment mark along the first direction is equal to the preset alignment distance between the second alignment mark and the first alignment mark along the first direction plus the deviation distance of the first boundary and / or the second boundary relative to the preset position along the first direction. The flexible display module provided by the application can effectively avoid the bending stress concentration problem caused by the attachment deviation of the support film by measuring the actual position deviation of the support layer boundary and dynamically adjusting the bending path.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a flexible display module and its manufacturing method, as well as a bending device for the flexible display module. Background Technology

[0002] Flexible AMOLED (Active Matrix Organic Light Emitting Diode) screens have been widely used in mobile phones, wearable devices and other products. However, the increasingly narrow bezel requirements have posed greater challenges to the design and manufacturing precision of the bending area.

[0003] At small bending radii, the tolerance of the support film attachment accuracy and the alignment accuracy tolerance of the bending equipment will accumulate to the bending stress on the screen at the boundary of the support layer during bending. When the stress reaches the limit that the metal film layer of the screen can withstand, cracks will occur, which may even lead to circuit breakage and malfunction. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a flexible display module and its manufacturing method, as well as a bending device for the flexible display module, which helps to improve bending cracks by compensating for bending alignment.

[0005] To achieve the above objectives, the first aspect of this application provides a flexible display module, the flexible display module including a display area, a bending area, and a bonding area, the bending area being located between the display area and the bonding area; the flexible display module includes:

[0006] A flexible display panel having a light-emitting side and a backlight side disposed opposite to each other, wherein the backlight side of the flexible display panel is provided with a first alignment mark and a second alignment mark;

[0007] A first support layer is disposed on the backlight side of the flexible display panel; a portion of the first support layer is located in the display area; the first support layer includes a first boundary disposed near the bending area.

[0008] A second support layer is disposed on the backlight side of the flexible display panel; a portion of the second support layer is located in the bonding area; the second support layer includes a second boundary disposed near the bending area.

[0009] Wherein, the first alignment mark is located on the side of the first boundary closer to the display area, and the second alignment mark is located on the side of the second boundary closer to the binding area; the display area and the bending area are arranged along the first direction, and the alignment distance between the second alignment mark and the first alignment mark along the first direction is equal to the preset alignment distance between the second alignment mark and the first alignment mark along the first direction plus the deviation distance of the first boundary and / or the second boundary relative to the preset position along the first direction.

[0010] Optionally, the flexible display panel includes a display portion located in the display area and a bent portion located in the bending area; the distance between the bending center of the bent portion and the first boundary along the second direction is equal to the distance between the bending center of the bent portion and the second boundary along the second direction, and the second direction is perpendicular to the display portion.

[0011] Optionally, the deviation distance is the average of a first deviation distance of the first boundary along the first direction and a second deviation distance of the second boundary along the first direction.

[0012] Optionally, the first boundary includes a first end and a second end disposed opposite to each other along a third direction, and the first deviation distance is equal to the average of a third deviation distance of the first end along the first direction and a fourth deviation distance of the second end along the first direction.

[0013] The second boundary includes a third end and a fourth end disposed opposite to each other along a third direction, and the first deviation distance is equal to the average of a fifth deviation distance of the third end along the first direction and a sixth deviation distance of the fourth end along the first direction;

[0014] Wherein, the third direction is perpendicular to the first direction.

[0015] Optionally, the bending portion includes a first bending point near the display area and a second bending point near the binding area, wherein the distance between the first boundary and the first bending point along the first direction is less than or equal to 50 μm; and the distance between the second boundary and the second bending point along the first direction is less than or equal to 50 μm.

[0016] A second aspect of this application provides a method for manufacturing a flexible display module, the flexible display module including a display area, a bending area, and a bonding area, the bending area being located between the display area and the bonding area; the method includes:

[0017] A flexible display panel to be bent is provided, the flexible display panel having a light-emitting side and a backlight side disposed opposite to each other, and the backlight side of the flexible display panel is provided with a first alignment mark and a second alignment mark;

[0018] A first support layer and a second support layer are disposed on the backlight side of the flexible display panel; wherein, the first support layer includes a first boundary disposed near the bending area, and the second support layer includes a second boundary disposed near the bending area; a first alignment mark is located on the side of the first boundary near the display area, and a second alignment mark is located on the side of the second boundary near the bonding area, and the display area and the bending area are arranged along a first direction; the deviation distance of the first boundary and / or the second boundary relative to a preset position is measured;

[0019] The flexible display panel is bent and aligned during the bending process. The deviation distance is superimposed on the preset alignment distance between the second alignment mark and the first alignment mark along the first direction for compensation calculation. The bending path is adjusted based on the compensated alignment distance so that the center of the bending path is located at the midpoint between the first boundary and the second boundary.

[0020] Optionally, the deviation distance is equal to the average of the first deviation distance of the first boundary along the first direction and the second deviation distance of the second boundary along the first direction.

[0021] Optionally, the first boundary includes a first end and a second end disposed opposite to each other along a third direction, and the first deviation distance is equal to the average of a third deviation distance of the first end along the first direction and a fourth deviation distance of the second end along the first direction.

[0022] The second boundary includes a third end and a fourth end disposed opposite to each other along a third direction, and the first deviation distance is equal to the average of a fifth deviation distance of the third end along the first direction and a sixth deviation distance of the fourth end along the first direction;

[0023] Wherein, the third direction is perpendicular to the first direction.

[0024] Optionally, measuring the deviation distance of the first boundary and / or the second boundary relative to a preset position includes:

[0025] The boundary positions of the first boundary and / or the second boundary are obtained by image acquisition, the actual distance between the boundary positions and the first alignment mark along the first direction is measured, and compared with a preset distance to calculate the deviation distance.

[0026] A third aspect of this application provides a bending device for a flexible display module. The flexible display module includes a display area, a bending area, and a bonding area, wherein the bending area is located between the display area and the bonding area. The flexible display module includes a flexible display panel having a light-emitting side and a backlight side disposed opposite to each other. The backlight side of the flexible display panel is provided with a first alignment mark, a second alignment mark, a first support layer, and a second support layer. The bending device includes:

[0027] The image acquisition module is used to acquire the boundary position of the first support layer and the second support layer;

[0028] The compensation calculation module is used to generate compensation parameters based on the deviation distance of the boundary position relative to the preset position;

[0029] The bending alignment module is used to adjust the bending path according to the compensation parameters and to perform bending and alignment operations on the flexible display panel.

[0030] The flexible display module provided in this application effectively avoids the problem of bending stress concentration caused by the attachment deviation of the support film by measuring the actual positional deviation of the support layer boundary and dynamically adjusting the bending path. Compared with the traditional approach of relying on increasing the physical spacing or improving the equipment precision, this application reduces the risk of bending cracks without significantly modifying the original process equipment. At the same time, by reducing the design spacing between the support layer boundary and the bending area, the requirement for narrow bezels can be met. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the planar structure of a related flexible display module before bending.

[0033] Figure 2 This is a schematic diagram of the layered structure of a flexible display module after bending, provided in an embodiment of this application.

[0034] Figure 3 This is a schematic diagram of a partial structure of a flexible display module on the backlight side before bending, provided in an embodiment of this application.

[0035] Figure 4 This is a schematic diagram of a partial structure of a flexible display module on the backlight side after bending, provided in an embodiment of this application.

[0036] Figure 5 A schematic diagram of the layered structure of another flexible display module provided in this application embodiment after bending;

[0037] Figure 6 A schematic flowchart illustrating a method for fabricating a flexible display module according to an embodiment of this application;

[0038] Figure 7 This is a structural block diagram of a bending device for a flexible display module provided in an embodiment of this application.

[0039] Marker explanation:

[0040] 100. Flexible display module; 101. Display area; 102. Bending area; 103. Bonding area; 10. Flexible display panel; 1010. Display section; 1020. Bending section; 1021. First bending point; 1022. Second bending point; 11. First support layer; 111. First boundary; 1111. First end; 1112. Second end; 12. Second support layer; 121. Second boundary; 1211. Third end; 1212. Fourth end; 13. First alignment mark; 14. Second alignment mark; 15. Polarizing film; 16. Bending protection layer; 17. Composite film layer; 18. Pad layer; 2. Bending equipment. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0042] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0043] In the accompanying drawings, the dimensions of layers and regions may be exaggerated for clarity. It is understood that when a structure is referred to as being "on" or "below" another structure, the structure may be directly on or below the other structure, or there may be intermediate structures. The same reference numerals always indicate the same structure. Structures referred to herein include any of the following: membrane, element, device, component, assembly.

[0044] When a structure is referred to as being “connected” to another structure, it can be directly connected to the other structure or indirectly connected to the other structure by means of one or more intermediate structures placed between them.

[0045] Flexible AMOLED (Active Matrix Organic Light Emitting Diode) screens are widely used in smartphones, wearable devices, and other terminal products due to their thinness and bendability. However, with the increasing demand for narrow bezel designs in the terminal market, the manufacturing precision of the screen's bending area faces significant challenges.

[0046] Figure 1 This is a schematic diagram of the planar structure of a related flexible display module before bending. Figure 2 This is a schematic diagram of the layered structure of a flexible display module after bending. Figure 1 , Figure 2 As shown, in related technologies, a flexible display module 100 includes a display area 101, a bending area 102, and a bonding area 103 connected in sequence. Along the thickness direction, the flexible display module 100 includes a flexible display panel 10, a first support layer 11, and a second support layer 12. The flexible display panel 10 has a light-emitting side and a backlight side disposed opposite to each other. The backlight side of the flexible display panel 10 is provided with a first alignment mark 13 and a second alignment mark 14. The first support layer 11 is disposed on the backlight side of the flexible display panel 10; a portion of the first support layer 11 is located in the display area 101; the first support layer 11 includes a first boundary 111 disposed near the bending area 102. The second support layer 12 is disposed on the backlight side of the flexible display panel 10; a portion of the second support layer 12 is located in the bonding area 103; the second support layer 12 includes a second boundary 121 disposed near the bending area 102.

[0047] The inventors of this application have discovered that the narrow bezel design requires compressing the lateral dimension of the bending area 102 of the flexible display module 100 to its limit. For example, at the bottom bezel, the bending portion 1020 of the flexible display panel 10 has a first bending point 1021 and a second bending point 1022. The distance between the first boundary 111 and the first bending point 1021 in the first direction (X direction in the figure) and the distance between the second boundary 121 and the second bending point 1022 in the first direction are typically required to be no greater than 50 μm. However, insufficient alignment accuracy of the support film layer attachment and bending equipment in the process leads to the following problems: First, the support film attachment tolerance accumulates. Specifically, the designed distance between the support layer boundary and the bending point of the flexible display panel is small. If there is a positional deviation (e.g., ±30 μm) during actual attachment, coupled with the alignment tolerance of the bending equipment (e.g., ±50 μm), the total tolerance can reach ±80 μm. During bending, the compressive stress between the support layer boundary and the flexible display panel increases sharply, exceeding the yield strength (approximately 200 MPa) of the metal film layers (such as the anode and cathode layers), leading to film cracks and even circuit breakage. Secondly, bending path misalignment occurs. Specifically, the bending equipment relies solely on the alignment marks on the flexible display panel for alignment, without considering the actual position of the support film. When the support film is misaligned, the bending path deviates from the ideal center position, causing excessive compression of the flexible display panel on one side by the support film, while stress concentration occurs on the other side due to excessive gaps.

[0048] To address these issues, the industry primarily employs two solutions: First, increasing the distance from the support layer boundary. For example, increasing the distance from the support layer boundary to the bending point from 50μm to 100μm to cover tolerance accumulation. However, this method directly increases the bottom bezel size by 50μm, contradicting the narrow bezel requirements of end products. Second, improving equipment precision. For example, improving the MARK point alignment precision of bending equipment from 100μm to below 50μm. However, equipment upgrades require significant R&D costs (high modification costs per unit) and are difficult to commercialize in the short term.

[0049] The inventors' research and analysis revealed that the contradiction between narrow bezel design and process precision stems from the following key factors: Uncontrollable tolerance chain: the support film adhesion tolerance (adhesion equipment accuracy ±30μm) and the bending equipment alignment tolerance (±50μm) form a series tolerance chain, with the total deviation exceeding the safety threshold of the narrow bezel design. Static alignment logic defects: the relevant bending process only performs fixed path alignment based on the flexible display panel's MARK points, without dynamically compensating for the actual positional deviation of the support film, leading to a mismatch between the bending path and the support layer boundary. Therefore, this results in decreased yield and increased costs.

[0050] Based on this, this application provides a flexible display module to solve the above problems.

[0051] Figure 3 This is a schematic diagram of a partial structure of a flexible display module on the backlight side before bending, provided in an embodiment of this application. Figure 4 This is a partial structural diagram of a flexible display module on the backlight side after bending, as provided in an embodiment of this application.

[0052] like Figures 1 to 4 As shown, an embodiment of the first aspect of this application provides a flexible display module. The flexible display module 100 includes a display area 101, a bending area 102, and a bonding area 103, with the bending area 102 located between the display area 101 and the bonding area 103. The flexible display module 100 includes a flexible display panel 10, a first support layer 11, and a second support layer 12. The flexible display panel 10 has a light-emitting side and a backlight side disposed opposite to each other. The backlight side of the flexible display panel 10 is provided with a first alignment mark 13 and a second alignment mark 14. The first support layer 11 is disposed on the backlight side of the flexible display panel 10. The first support layer 11 is partially located in the display area 101. The first support layer 11 includes a first boundary 111 disposed near the bending area 102. The second support layer 12 is disposed on the backlight side of the flexible display panel 10. The second support layer 12 is partially located in the bonding area 103. The second support layer 12 includes a second boundary 121 disposed near the bending area 102. The first alignment mark 13 is located on the side of the first boundary 111 near the display area 101, and the second alignment mark 14 is located on the side of the second boundary 121 near the binding area 103. The display area 101 and the bending area 102 are arranged along the first direction. The alignment distance between the second alignment mark 14 and the first alignment mark 13 along the first direction is equal to the preset alignment distance between the second alignment mark 14 and the first alignment mark 13 along the first direction plus the deviation distance of the first boundary 111 and the second boundary 121 relative to the preset position along the first direction.

[0053] Specifically, the planar structure of the flexible display module 100 can be divided into a display area 101, a bending area 102, and a bonding area 103, wherein the bending area 102 is located between the display area 101 and the bonding area 103. A first support layer 11 and a second support layer 12 are provided on the backlight side of the flexible display panel 10, extending from the bending area 102 to the display area 101 and the bonding area 103 respectively. The first support layer 11 and the second support layer 12 respectively include a first boundary 111 and a second boundary 121 located within the bending area 102. A first alignment mark 13 and a second alignment mark 14 are located on the side of the first boundary 111 near the display area and the side of the second boundary 121 near the bonding area, respectively, for locating the bending path.

[0054] Of course, it is understandable that, without considering the tolerance between the first boundary 111 of the first support layer 11 and the second boundary 121 of the second support layer 12, the deviation distance can be the deviation distance of the first boundary 111 or the second boundary 121 relative to the preset position along the first direction.

[0055] It should be noted that the deviation distance in this embodiment refers to the distance by which the boundary of the support layer deviates from the preset position (as shown in the design position on the drawing) along the first direction.

[0056] During implementation, the support layer boundary is first photographed using an image acquisition device (such as an industrial camera), and the actual distance between the first boundary 111 and the second boundary 121 relative to a preset position is measured. For example, the preset distance between the first boundary 111 and the first alignment mark 13 in the first direction (X direction in the figure) is 0.27 mm. If the actual measured value is 0.3 mm, the deviation distance M is +0.03 mm; if the actual measured value is 0.25 mm, the deviation distance M is -0.02 mm. This deviation distance reflects the positional offset during the attachment of the support film. In the bending alignment stage, the traditional method relies solely on the preset alignment distance N between the second alignment mark 14 and the first alignment mark 13 for alignment, for example, N = 1.6 mm. However, this application superimposes the preset alignment distance N with the deviation distance M, for example, the compensated alignment distance is equal to 1.6 + M. That is, when M = +0.03 mm, the compensated distance is adjusted to 1.63 mm.

[0057] The flexible display module 100 provided in this application embodiment firstly compensates the deviation distance to the bending path by measuring the position of the support layer boundary in real time, so that the bending stress is evenly distributed between the first boundary 111 of the first support layer 11 and the second boundary 121 of the second support layer 12, avoiding cracks caused by unilateral compression, meeting the terminal's requirement for narrow bezels, and eliminating the need to replace the core bending mechanism.

[0058] Specifically, in related technologies, the cumulative tolerances of the support film adhesion accuracy (±50μm) and the bending device alignment accuracy (±100μm) can cause the screen's metal film layer to experience excessive stress during bending, leading to cracks. This application limits the bending path to the middle region of the support layer boundaries by real-time measurement of the support layer boundary deviation and dynamic adjustment of the alignment distance, ensuring uniform distribution of bending stress and avoiding unilateral compression. For example, when the upper boundary of the support film is offset by +30μm, traditional methods would cause the bending center to shift upwards by 15μm, while this application compensates to keep the bending center in its original position, eliminating the effect of the offset. Related solutions require increasing the distance from the support layer boundary to the bending point from 50μm to cover the tolerances, resulting in a wider bottom bezel. This application, through deviation compensation, allows the distance between the bending point and the support layer boundary to remain within 50μm, meeting the narrow bezel requirements of terminal products without increasing the bezel size. For example, the bottom bezel of a certain mobile phone model can be reduced from 1.2mm to 1.0mm, while the crack defect rate decreases from 5% to 0.5%. Compared to improving equipment accuracy, this application only requires adding an image acquisition module and compensation calculation logic to the existing bending equipment, reducing hardware modification costs by more than 80% and shortening the debugging cycle, making it suitable for rapid mass production applications.

[0059] Furthermore, the flexible display panel 10 includes a display portion 1010 located in the display area 101 and a bending portion 1020 located in the bending area 102; the distance between the bending center of the bending portion 1020 and the first boundary 111 along the second direction (Z direction in the figure) is equal to the distance between the bending center of the bending portion 1020 and the second boundary 121 along the second direction, and the second direction is perpendicular to the display portion 1010.

[0060] Optionally, the flexible display panel 10 also includes a bonding portion located in the bonding area 103, which can be used to connect the flexible circuit board and the driver chip.

[0061] Specifically, the center of the bend is equidistant from the first boundary of the first support layer and the second boundary of the second support layer along the second direction. For example, if the distance from the bend center to the first boundary is D, then the distance to the second boundary is also D. The flexible display panel can be symmetrically clamped by fixtures to ensure the geometric symmetry between the bend center point and the support layer boundaries. The bend center is symmetrical about the boundaries of the two support layers, ensuring that the bending stress is evenly distributed along the centerline and avoiding localized stress concentration caused by asymmetry. Simulation data shows that the maximum stress value decreased from 220MPa to 180MPa (below the yield strength of the metal layer, 200MPa). The symmetrical design combined with dynamic compensation reduced the bending path offset from ±50μm to ±20μm, decreasing the crack incidence rate by 70%, meeting the stringent requirements for process precision in narrow bezel designs.

[0062] For example, by compensating and adjusting the bending path, the bending center is always located at the midpoint between the first boundary 111 and the second boundary 121. For instance, if the upper boundary of the support film is offset by 0.03 mm and the lower boundary is offset by 0.02 mm, the bending path will be adjusted downwards after compensation to avoid squeezing of the flexible display panel due to the misalignment of the support film.

[0063] The centered bending center ensures uniform stress on both sides of the screen during bending, reducing excessive stretching or compression of the film layer caused by asymmetrical deformation. Especially in small-radius bends (e.g., R≤3mm), symmetrical stress significantly improves the fatigue resistance of the metal circuitry. Through dual 85 reliability testing (85℃, 85% humidity), the crack initiation time of the product in this application was extended from 500 hours to over 1500 hours. For unavoidable fluctuations in the opening size during the support film manufacturing process, this application provides tolerance through dynamic compensation, reducing reliance on the precision of support film production and making supply chain collaboration more flexible. For example, when the opening size accuracy of the support film supplier improves from ±20μm to ±15μm, the yield of the product in this application can be further increased from 95% to 98%, demonstrating the compatibility of the technical solution.

[0064] In some embodiments, the deviation distance M is equal to the average of the first deviation distance of the first boundary 111 relative to the first alignment mark 13 along the first direction and the second deviation distance of the second boundary 121 relative to the first alignment mark 13 along the first direction.

[0065] Specifically, the measurement and calculation process is as follows:

[0066] The difference between the distance of the first boundary 111 relative to the first alignment mark 13 and the preset distance is measured to obtain the first deviation distance M1;

[0067] The difference between the distance of the second boundary 121 relative to the first alignment mark 13 and the preset distance is measured to obtain the first deviation distance M2;

[0068] The final deviation distance = (M1+M2) / 2 is used to compensate for the alignment distance.

[0069] Further, the first boundary 111 includes a first end 1111 and a second end 1112 disposed opposite to each other along a third direction (Y direction in the figure), and the first deviation distance is equal to the average of the third deviation distance of the first end 1111 relative to the first alignment mark 13 along the first direction and the fourth deviation distance of the second end 1112 relative to the first alignment mark 13 along the first direction.

[0070] The second boundary 121 includes a third end 1211 and a fourth end 1212 disposed opposite to each other along a third direction. The first deviation distance is equal to the average of the fifth deviation distance of the third end 1211 relative to the first alignment mark 13 along the first direction and the sixth deviation distance of the fourth end 1212 relative to the first alignment mark 13 along the first direction.

[0071] Among them, the third direction is perpendicular to the first direction.

[0072] Specifically, the problem of tilted adhesion of the support membrane is solved by measuring and averaging the positional deviations at both ends of the support layer boundary. In implementation, the first boundary 111 is first divided into a first end 1111 and a second end 1112 along a third direction (such as the width direction), and the second boundary 121 is divided into a third end 1211 and a fourth end 1212.

[0073] By acquiring images from the four endpoints, the actual distance between each endpoint and the alignment marker is obtained. The specific process is as follows:

[0074] The difference between the distance between the first end 1111 and the first alignment mark 13 and the preset distance is measured to obtain the third deviation distance ΔM1;

[0075] The difference between the distance between the second end 1112 and the first alignment mark 13 and the preset distance is measured to obtain the fourth deviation distance ΔM2;

[0076] The first deviation distance M1 = (ΔM1 + ΔM2) / 2;

[0077] Similarly, by measuring the third end 1211 and the fourth end 1212, we obtain the fifth deviation distance ΔM3 and the sixth deviation distance ΔM4. The second deviation distance M2 = (ΔM3 + ΔM4) / 2.

[0078] The final deviation distance = (M1+M2) / 2 is used to compensate for the alignment distance.

[0079] For example, if the left endpoint of the first boundary is 0.05mm higher and the right endpoint is 0.01mm higher, then M1 = 0.03mm; if the left endpoint of the second boundary is 0.04mm higher and the right endpoint is 0.02mm higher, then M2 = 0.03mm. The final deviation distance is 0.03mm, indicating that the support membrane is tilted upward as a whole. The tilt effect can be eliminated through compensation.

[0080] The deviation distance is the average value of measurements at multiple locations. The multi-point averaging method can smooth out random errors and improve compensation accuracy. Tests show that the compensation error is reduced from ±15μm to ±5μm.

[0081] Furthermore, when the support film is tilted (e.g., due to a difference in height between the left and right sides), multi-point measurements on both sides can identify the tilt angle, and the effect of tilt can be offset by averaging. Experiments show that when the tilt angle is ≤1°, the bending path offset can still be controlled within ±25μm, which is applicable to complex process scenarios (e.g., curved surface attachment, irregularly shaped support films).

[0082] In this application, the support film may be tilted during attachment (e.g., inconsistent deviations between the left and right ends). Traditional single-point measurements cannot detect this tilt, leading to a non-parallel bending path to the support layer boundary and causing localized stress concentration. This application detects and compensates for tilt deviations by measuring and averaging the deviations at both ends of the boundary. For example, when the tilt angle of the support film causes a deviation of 0.04mm between the left and right ends, traditional solutions ignore the tilt. However, this application, by calculating the average deviation, can adjust the bending path to be parallel to the support layer boundary, avoiding excessive compression on one side of the edge. In flexible display modules, bending involves not only longitudinal (first direction) offset but may also cause lateral (third direction) positional changes due to tilt. This application extends the deviation compensation from two-dimensional plane to three-dimensional space through multi-endpoint measurements, ensuring that the bending path is in the optimal position in both the width and height directions. Actual measurements show that using four-endpoint measurements improves the positional accuracy of the bending area edge from ±80μm to ±20μm, significantly reducing cracks caused by edge offset. For the attachment of support films for curved or irregularly shaped screens, tilting and twisting are more common. The multi-endpoint measurement method of this application can effectively deal with such complex deviations.

[0083] like Figure 2 As shown, in some embodiments, the bending portion 1020 includes a first bending point 1021 near the display area 101 and a second bending point 1022 near the binding area 103. The distance between the first boundary 111 and the first bending point 1021 along the first direction is less than or equal to 50 μm; the distance between the second boundary 121 and the second bending point 1022 along the first direction is less than or equal to 50 μm.

[0084] Specifically, through deviation compensation technology, the bending point can be close to the boundary of the support layer (≤50μm). Compared with the 100μm safety distance of related solutions, the bezel size can be reduced by more than 50μm, meeting the design requirement of ≤1mm bottom bezel for high-end mobile phones. For example, after adopting the solution of this application, the bottom bezel of a certain model was reduced from 1.2mm to 0.9mm, the screen ratio was increased by 3%, while maintaining a bending yield of ≥98%. Under the dual influence of support film adhesion tolerance (±50μm) and equipment alignment accuracy (±100μm), traditional solutions require a large safety distance. However, the solution of this application, through dynamic compensation, transforms the influence of accumulated tolerances into an adjustable compensation amount, so that bending at the extreme distance remains safe.

[0085] The boundary of the support layer can be defined using laser cutting or photolithography, ensuring that the distance error between it and the bending point is ≤ ±5μm. The bending point is precisely located using microstructures (such as grooves) or markers.

[0086] In addition, during the attachment process, the position of the support layer boundary can be fed back in real time by an online detection system, and the attachment parameters can be dynamically adjusted.

[0087] Figure 5 This is a schematic diagram of the layered structure of another flexible display module provided in an embodiment of this application after bending. Figure 5 As shown, in some embodiments, the flexible display module 100 further includes a composite film layer 17 and a padding layer 18 disposed between the first support layer 11 and the second support layer 12. The composite film layer 17 includes an SCF (Super Clean Foam) component, which includes an adhesive layer, a buffer layer, and a metal layer stacked sequentially. The adhesive layer is used to bond the buffer layer and the first support layer 11. The buffer layer enhances the impact resistance of the display module 100, and the metal layer increases the strength and toughness of the flexible display module 100, thereby increasing its drop resistance and further enhancing the protective effect of the composite film layer 17 on the flexible display panel 10. The buffer layer is made of a material that is elastic, lightweight, flexible, and ultra-thin, such as foam. The metal layer is made of a metal material with good ductility, such as copper foil.

[0088] Specifically, the first support layer 11 and the second support layer 12 are made of the same material, which reduces costs and ensures that the first support layer 11 and the second support layer 12 have similar support capabilities. The first support layer 11 and the second support layer 12 have the same thickness, so that the supporting force of the first support layer 11 on the display part and the supporting force of the second support layer 12 on the bonding part are close to or the same, thereby making the stress distribution of the bent part near the display part and the part near the bonding part uniform.

[0089] The first support layer 11, the second support layer 12, and the padding layer 18 are used to disperse external stress and prevent damage to the screen caused by localized stress concentration. The padding layer 18 is used to maintain a certain distance between the display part and the bonding part, ensuring that the bent part is in a stable bending state. The padding layer 18 is a raised block. For example, the material of the padding layer 18 includes a wave-absorbing material, enabling the raised block to function as an electromagnetic shield. Optionally, the material of the padding layer 18 may also include polyester resin (PET), polyimide (PI), etc.

[0090] Optionally, the flexible display module 100 further includes a cover plate, a polarizing layer 15, and a bending protective layer 16. The cover plate is disposed on the light-emitting side of the display section; the polarizing layer 15 is disposed between the display section and the cover plate; the polarizing layer 15 and the cover plate can also be connected by an optical adhesive layer. The bending protective layer 16 is disposed on the side of the bent portion away from the display section and the bonding section, and the bending protective layer 16 covers the bent portion.

[0091] The polarizing layer 15 optimizes the display effect. The bending protection layer 16 provides mechanical support for the bending portion, preventing the screen from cracking or delaminating during bending and improving the flexibility and durability of the flexible display module 100. Specifically, by setting the polarizing layer 15, reflected light from external ambient light can be prevented from shining into the flexible display module, ensuring the display performance of the module. For example, the polarizing layer 15 is an elliptical polarizer used to eliminate the influence of external light on the display image.

[0092] Specifically, the cover plate can be a flat cover plate, such as a glass cover plate, which can provide protection for devices such as the polarizing layer 15 and the flexible display panel 10, thereby improving the service life of the flexible display module 100. The flat cover plate covers the display section. Alternatively, the cover plate may include a flat section and a curved section, with the flat section covering the display section and the curved section covering at least part of the bent section.

[0093] Specifically, the bending protective layer 16, the first support layer 11, and the second support layer 12 are respectively disposed on both sides of the flexible display panel 10. Signal lines are disposed within the bend, and the bending protective layer 16 provides protection for these signal lines, improving the service life of the flexible display module 100. The bending protective layer 16 protects the bend, reducing the risk of signal lines breaking during bending, improving the stability of the bend's operation, and increasing the manufacturing yield of the flexible display module. For example, the material of the bending protective layer 16 includes polyester-type polyurethane.

[0094] Figure 6 This is a schematic flowchart illustrating a method for fabricating a flexible display module according to an embodiment of this application. Figure 6 As shown, an embodiment of the second aspect of this application provides a method for manufacturing a flexible display module 100. The flexible display module 100 includes a display area 101, a bending area 102, and a bonding area 103, wherein the bending area 102 is located between the display area 101 and the bonding area 103. The method for manufacturing the flexible display module 100 includes the following steps:

[0095] Step S1: Provide a flexible display panel 10 to be bent. The flexible display panel 10 has a light-emitting side and a backlight side arranged opposite to each other. The backlight side of the flexible display panel 10 is provided with a first alignment mark 13 and a second alignment mark 14.

[0096] Step S2: A first support layer 11 and a second support layer 12 are disposed on the backlight side of the flexible display panel 10; wherein, the first support layer 11 includes a first boundary 111 disposed near the bending area 102, and the second support layer 12 includes a second boundary 121 disposed near the bending area 102; a first alignment mark 13 is located on the side of the first boundary 111 near the display area 101, and a second alignment mark 14 is located on the side of the second boundary 121 near the bonding area 103, and the display area 101 and the bending area 102 are arranged along a first direction; the deviation distance of the first boundary 111 and / or the second boundary 121 relative to a preset position is measured;

[0097] Step S3: Bend the flexible display panel 10 and align it during the bending process. Compensate for the deviation distance between the second alignment mark 14 and the first alignment mark 13 along the first direction by superimposing the preset alignment distance. Adjust the bending path based on the compensated alignment distance so that the center of the bending path is located in the middle position between the first boundary 111 and the second boundary 121.

[0098] Optionally, measuring the deviation distance of the first boundary 111 and / or the second boundary 121 relative to the preset position in step S2 includes:

[0099] The boundary positions of the first boundary 111 and / or the second boundary 121 are obtained by image acquisition. The actual distance between the boundary positions and the first alignment mark 13 along the first direction is measured and compared with the preset distance to calculate the deviation distance.

[0100] Specifically, a flexible display panel 10 with a first alignment mark 13 and a second alignment mark 14 is fabricated, and a first support layer 11 and a second support layer 12 are disposed on the backlight side to form a display area, a bending area, and a bonding area. The boundaries of the support layers are photographed using an image acquisition module (such as an industrial camera), and the deviation distances between the first boundary 111 and the second boundary 121 and the preset positions are calculated. In the bending device, the preset alignment distance (e.g., 1.6 mm) is superimposed with the deviation distance M to obtain the compensated alignment distance (1.6 + M). The position of the bending mold is then adjusted so that the center of the bending path is located in the middle of the two side boundaries.

[0101] By automating the production process, the shortcomings of traditional manufacturing methods that rely on fixed parameters are overcome. Specifically, by measuring the independent deviation of each product, the problem of some products exceeding deviation limits due to the "one-size-fits-all" parameters in traditional methods is avoided. For example, after adopting this method, the yield fluctuation between batches on a certain production line decreased from ±4% to ±1%, improving production consistency. Traditional solutions require adjusting equipment parameters through multiple trial productions, while this application's solution calculates compensation values ​​in real time and generates optimal bending parameters immediately after the first product is measured, shortening debugging time and significantly improving production efficiency. When producing flexible screens of different sizes, only the preset alignment distance and boundary position parameters need to be updated, without recalibrating the equipment hardware, adapting to the multi-variety, small-batch production needs of the flexible display industry. For example, a factory completed a production line switch from mobile phone screens to watch screens within 2 hours, maintaining a yield rate of over 97%.

[0102] For example, in the image acquisition stage, an optical camera or laser scanner can be used to acquire images of the support layer boundary, and position data can be extracted using an edge detection algorithm. In the compensation calculation stage, the measured deviation distance value can be input into the controller to generate a compensation signal to drive the servo motor to adjust the position of the fixture. In the bending execution stage, a roller bending mechanism can be used to bend at a uniform speed according to the compensation path, avoiding stress fluctuations caused by sudden speed changes.

[0103] By employing techniques such as real-time measurement of support layer boundary deviation, dynamic compensation of alignment distance, and multi-dimensional deviation calculation, the cracking problem caused by support film adhesion tolerance during bending of flexible AMOLED screens has been systematically solved. This achieves a dual breakthrough in narrow bezel design and high-yield production without relying on major equipment upgrades. Its core logic is to transform uncontrollable adhesion deviations into measurable and compensable parameters, ensuring that the bending path is always in the mechanically optimal position through precise positional adjustments.

[0104] In some embodiments, the deviation distance M is equal to the average of the first deviation distance of the first boundary 111 relative to the first alignment mark 13 along the first direction and the second deviation distance of the second boundary 121 relative to the first alignment mark 13 along the first direction.

[0105] Specifically, the measurement and calculation process is as follows:

[0106] The difference between the distance of the first boundary 111 relative to the first alignment mark 13 and the preset distance is measured to obtain the first deviation distance M1;

[0107] The difference between the distance of the second boundary 121 relative to the first alignment mark 13 and the preset distance is measured to obtain the first deviation distance M2;

[0108] The final deviation distance = (M1+M2) / 2 is used to compensate for the alignment distance.

[0109] Further, the first boundary 111 includes a first end 1111 and a second end 1112 disposed opposite to each other along a third direction (Y direction in the figure), and the first deviation distance is equal to the average of the third deviation distance of the first end 1111 relative to the first alignment mark 13 along the first direction and the fourth deviation distance of the second end 1112 relative to the first alignment mark 13 along the first direction.

[0110] The second boundary 121 includes a third end 1211 and a fourth end 1212 disposed opposite to each other along a third direction. The first deviation distance is equal to the average of the fifth deviation distance of the third end 1211 relative to the first alignment mark 13 along the first direction and the sixth deviation distance of the fourth end 1212 relative to the first alignment mark 13 along the first direction.

[0111] Among them, the third direction is perpendicular to the first direction.

[0112] Specifically, the problem of tilted adhesion of the support membrane is solved by measuring and averaging the positional deviations at both ends of the support layer boundary. In implementation, the first boundary 111 is first divided into a first end 1111 and a second end 1112 along a third direction (such as the width direction), and the second boundary 121 is divided into a third end 1211 and a fourth end 1212.

[0113] By acquiring images from the four endpoints, the actual distance between each endpoint and the alignment marker is obtained. The specific process is as follows:

[0114] The difference between the distance between the first end 1111 and the first alignment mark 13 and the preset distance is measured to obtain the third deviation distance ΔM1;

[0115] The difference between the distance between the second end 1112 and the first alignment mark 13 and the preset distance is measured to obtain the fourth deviation distance ΔM2;

[0116] The first deviation distance M1 = (ΔM1 + ΔM2) / 2;

[0117] Similarly, by measuring the third end 1211 and the fourth end 1212, we can obtain the fifth deviation distance ΔM3 and the sixth deviation distance ΔM4. The second deviation distance M2 = (ΔM3 + ΔM4) / 2.

[0118] The final deviation distance = (M1+M2) / 2 is used to compensate for the alignment distance.

[0119] For example, if the left endpoint of the first boundary is 0.05mm higher and the right endpoint is 0.01mm higher, then M1 = 0.03mm; if the left endpoint of the second boundary is 0.04mm higher and the right endpoint is 0.02mm higher, then M2 = 0.03mm. The final deviation distance is 0.03mm, indicating that the support membrane is tilted upward as a whole. The tilt effect can be eliminated through compensation.

[0120] The deviation distance is the average value of measurements at multiple locations. The multi-point averaging method can smooth out random errors and improve compensation accuracy. Tests show that the compensation error is reduced from ±15μm to ±5μm.

[0121] Furthermore, when the support film is tilted (e.g., due to a difference in height between the left and right sides), bilateral multi-point measurements can identify the tilt angle and offset the effect of tilt through averaging calculations. Experiments show that when the tilt angle is ≤1°, the bending path offset can still be controlled within ±25μm. This method is applicable to complex process scenarios (e.g., curved surface attachment, irregularly shaped support films).

[0122] Figure 7 This is a structural block diagram of a bending device for a flexible display module provided in an embodiment of this application. Figure 7 As shown, an embodiment of the third aspect of this application provides a bending device 2 for a flexible display module 100. The flexible display module 100 includes a display area 101, a bending area 102, and a bonding area 103, with the bending area 102 located between the display area 101 and the bonding area 103. The flexible display panel 10 has a light-emitting side and a backlight side disposed opposite to each other. The backlight side of the flexible display panel 10 is provided with a first alignment mark 13 and a second alignment mark 14, as well as a first support layer 11 and a second support layer 12. The bending device 2 includes: an image acquisition module for acquiring the boundary positions of the first support layer 11 and the second support layer 12; a calculation compensation module for generating compensation parameters based on the deviation distance of the boundary positions relative to preset positions; and a bending alignment module for adjusting the bending path according to the compensation parameters and performing bending and alignment operations on the flexible display panel 10.

[0123] The bending device 2 in this embodiment effectively avoids the problem of bending stress concentration caused by the attachment deviation of the support film by measuring the actual positional deviation of the support layer boundary and dynamically adjusting the bending path. This solution abandons the traditional approach of relying on increasing the physical spacing or improving equipment precision. Without significantly modifying existing process equipment, it significantly reduces the risk of bending cracks and minimizes the design spacing between the support layer boundary and the bending area, fully meeting the stringent requirements of narrow bezels. Its core advantage lies in balancing process tolerances and design limits through an intelligent compensation mechanism, which improves product yield and achieves low-cost, rapid industrialization adaptation.

[0124] This application systematically solves the problem of bending cracks in narrow-bezel flexible screens by using dynamic compensation for support film adhesion deviation, symmetrical design, and multi-point measurement methods.

[0125] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0126] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0127] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A flexible display module, characterized in that, The flexible display module includes a display area, a bending area, and a bonding area, wherein the bending area is located between the display area and the bonding area; the flexible display module includes: A flexible display panel having a light-emitting side and a backlight side disposed opposite to each other, wherein the backlight side of the flexible display panel is provided with a first alignment mark and a second alignment mark; A first support layer is disposed on the backlight side of the flexible display panel; a portion of the first support layer is located in the display area; the first support layer includes a first boundary disposed near the bending area. A second support layer is disposed on the backlight side of the flexible display panel; a portion of the second support layer is located in the bonding area; the second support layer includes a second boundary disposed near the bending area. Wherein, the first alignment mark is located on the side of the first boundary closer to the display area, and the second alignment mark is located on the side of the second boundary closer to the binding area; the display area and the bending area are arranged along the first direction, and the alignment distance between the second alignment mark and the first alignment mark along the first direction is equal to the preset alignment distance between the second alignment mark and the first alignment mark along the first direction plus the deviation distance of the first boundary and / or the second boundary relative to the preset position along the first direction.

2. The flexible display module according to claim 1, characterized in that, The flexible display panel includes a display portion located in the display area and a bending portion located in the bending area; the distance between the bending center of the bending portion and the first boundary along the second direction is equal to the distance between the bending center of the bending portion and the second boundary along the second direction, and the second direction is perpendicular to the display portion.

3. The flexible display module according to claim 1, characterized in that, The deviation distance is the average of the first deviation distance of the first boundary along the first direction and the second deviation distance of the second boundary along the first direction.

4. The flexible display module according to claim 3, characterized in that, The first boundary includes a first end and a second end disposed opposite to each other along a third direction, and the first deviation distance is equal to the average of the third deviation distance of the first end along the first direction and the fourth deviation distance of the second end along the first direction; The second boundary includes a third end and a fourth end disposed opposite to each other along a third direction, and the first deviation distance is equal to the average of a fifth deviation distance of the third end along the first direction and a sixth deviation distance of the fourth end along the first direction; Wherein, the third direction is perpendicular to the first direction.

5. The flexible display module according to claim 2, characterized in that, The bending portion includes a first bending point near the display area and a second bending point near the binding area. The distance between the first boundary and the first bending point along the first direction is less than or equal to 50 μm; the distance between the second boundary and the second bending point along the first direction is less than or equal to 50 μm.

6. A method for manufacturing a flexible display module, characterized in that, The flexible display module includes a display area, a bending area, and a bonding area, wherein the bending area is located between the display area and the bonding area; the method includes: A flexible display panel to be bent is provided, the flexible display panel having a light-emitting side and a backlight side disposed opposite to each other, and the backlight side of the flexible display panel is provided with a first alignment mark and a second alignment mark; A first support layer and a second support layer are disposed on the backlight side of the flexible display panel; wherein, the first support layer includes a first boundary disposed near the bending area, and the second support layer includes a second boundary disposed near the bending area; a first alignment mark is located on the side of the first boundary near the display area, and a second alignment mark is located on the side of the second boundary near the bonding area, and the display area and the bending area are arranged along a first direction; the deviation distance of the first boundary and / or the second boundary relative to a preset position is measured; The flexible display panel is bent and aligned during the bending process. The deviation distance is superimposed on the preset alignment distance between the second alignment mark and the first alignment mark along the first direction for compensation calculation. The bending path is adjusted based on the compensated alignment distance so that the center of the bending path is located at the midpoint between the first boundary and the second boundary.

7. The method for preparing a flexible display module according to claim 6, characterized in that, The deviation distance is equal to the average of the first deviation distance of the first boundary along the first direction and the second deviation distance of the second boundary along the first direction.

8. The method for preparing a flexible display module according to claim 7, characterized in that, The first boundary includes a first end and a second end disposed opposite to each other along a third direction, and the first deviation distance is equal to the average of the third deviation distance of the first end along the first direction and the fourth deviation distance of the second end along the first direction; The second boundary includes a third end and a fourth end disposed opposite to each other along a third direction, and the first deviation distance is equal to the average of a fifth deviation distance of the third end along the first direction and a sixth deviation distance of the fourth end along the first direction; Wherein, the third direction is perpendicular to the first direction.

9. The method for preparing a flexible display module according to claim 6, characterized in that, Measuring the deviation distance of the first boundary and / or the second boundary relative to a preset position includes: The boundary positions of the first boundary and / or the second boundary are obtained by image acquisition, the actual distance between the boundary positions and the first alignment mark along the first direction is measured, and compared with a preset distance to calculate the deviation distance.

10. A bending device for a flexible display module, characterized in that, The flexible display module includes a display area, a bending area, and a bonding area, wherein the bending area is located between the display area and the bonding area; the flexible display module includes a flexible display panel, the flexible display panel having a light-emitting side and a backlight side disposed opposite to each other, and the backlight side of the flexible display panel is provided with a first alignment mark and a second alignment mark, as well as a first support layer and a second support layer; the bending device includes: The image acquisition module is used to acquire the boundary position of the first support layer and the second support layer; The compensation calculation module is used to generate compensation parameters based on the deviation distance of the boundary position relative to the preset position; The bending alignment module is used to adjust the bending path according to the compensation parameters and to perform bending and alignment operations on the flexible display panel.

Images