Display module and display device

Abstract

This application discloses a display module and a display device. The display module includes: a display panel, including a flexible substrate; a flexible ribbon cable; and a circuit board assembly located on the backlight side of the display panel. The circuit board assembly includes a substrate layer and a device layer. The substrate layer includes at least one planar device area and a bending area. The substrate layer also includes a body portion and a reinforcing structure. The reinforcing structure is located in the planar device area. The device layer includes circuit elements and circuit traces. The circuit elements are located in the planar device area, and the circuit traces are located in the bending area. At least one planar device area in the substrate layer is parallel to the functional plane, and at least part of the display panel, the flexible ribbon cable, and the bending area in the substrate layer are not parallel to the functional plane. The display module provided in this application uses a body portion in conjunction with a reinforcing structure in the circuit board assembly. By bending part of the body portion and part of the circuit traces through the bending area, a large curvature bending can be achieved, and the performance can remain stable for a long time, making it less prone to drive signal failure.

Description

Technical Field

[0001] This application relates to the field of display equipment technology, specifically to a display module and display device. Background Technology

[0002] When designing display modules with bending curvature, the industry typically breaks down the existing display panel, flexible cable, and printed circuit board assembly (PCBA) into multiple sub-PCBAs, which are then connected by flexible printed circuits (FPCs) to accommodate the curvature of the display module.

[0003] However, regardless of whether the PCBA design is retained or the design is broken down into a combination of PCBA and FPC, the performance of the display module still needs to be improved, specifically in terms of performance degradation over long-term use. Summary of the Invention

[0004] This application provides a display module and display device that can withstand long-term use under bending with large curvature and is less prone to performance problems such as drive signal attenuation or even failure.

[0005] In a first aspect, an embodiment of this application provides a display module, comprising: a display panel including a flexible substrate; a flexible ribbon cable connected to one side of the display panel; and a circuit board assembly located on the backlight side of the display panel, the circuit board assembly being connected to the end of the flexible ribbon cable away from the display panel. The circuit board assembly includes a substrate layer and a device layer stacked along the direction away from the display panel. The substrate layer includes at least one planar device area and a bending area arranged along a first direction. The substrate layer also includes a body portion and a reinforcing structure. The reinforcing structure is at least partially located in the planar device area. The device layer includes circuit elements and circuit traces. The circuit elements are at least partially located in the planar device area, and the circuit traces are connected to the circuit elements and are at least partially located in the bending area. At least one planar device area in the substrate layer is parallel to a functional plane, and at least part of the display panel, the flexible ribbon cable, and the bending area in the substrate layer are not parallel to the functional plane. The functional plane is the plane containing the surface of the reinforcing structure on the side away from the circuit element within the planar device area.

[0006] The display module provided in the first aspect of this application uses a circuit board assembly with a body and a reinforcing structure. By bending a portion of the body and some circuit traces in the bending area, it is possible to maintain stable performance for a long time under large curvature bending, and it is not easy to have problems such as drive signal attenuation or even failure. On the one hand, the circuit board assembly uses a whole body layer to avoid the risk of components falling off due to long-term bending. On the other hand, the reinforcing structure limits the bending resistance of the planar device area on the substrate layer, so that the circuit elements can be in the same plane parallel to the functional plane and avoid desoldering.

[0007] Secondly, according to embodiments of this application, a display device is provided, including the display module provided in any of the first aspects of this application. Attached Figure Description

[0008] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0009] Figure 1 This is a plan view of the assembly structure of a display module provided in the first aspect embodiment of this application; Figure 2 This is a schematic diagram of a planar unfolded structure of a display module provided in the first aspect embodiment of this application; Figure 3 yes Figure 1 A schematic diagram of a cross-sectional structure along the AA direction; Figure 4 yes Figure 1 Another cross-sectional structure diagram along the AA direction; Figure 5 This is a schematic diagram of the overall structure of a display device provided in the second aspect of this application.

[0010] in: 100 - Display panel; 100a - Backlight side; 100b - Light-emitting side; 200 - Flexible ribbon cable; 210 - First ribbon cable; 220 - Second ribbon cable; 300 - Circuit board assembly; 310 - Substrate layer; 311 - Body; 312 - Reinforcing structure; 320 - Device layer; 321 - Circuit element; 322 - Circuit trace; 323 - Bonding terminal; 400-Driver Chip; 500 - Display device; PA - Planar device area; PA1 - First device area; PA2 - Second device area; CA - Bending area; FP - Functional plane; FP1 - First plane; FP2 - Second plane; D - Gap; BA - Bonding area; X - First direction; Y - Second direction; In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale. Detailed Implementation

[0011] The features and exemplary embodiments of various aspects of this application will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a comprehensive understanding of this application. However, it will be apparent to those skilled in the art that this application can be implemented without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of this application by illustrating examples. In the accompanying drawings and the following description, at least some well-known structures and techniques are not shown to avoid unnecessarily obscuring the application; and, for clarity, the dimensions of some structures may be exaggerated. Furthermore, the features, structures, or characteristics described below can be combined in any suitable manner in one or more embodiments.

[0012] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of the display panel and display module of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0013] In related technologies, under the design requirements of small bending curvature and short bending time, the common approach is to use a PCBA to barely fit the display panel. This involves using a single PCBA or splitting the PCBA into multiple sub-PCBAs and connecting them via FPC to achieve a barely fitting fit between the circuit board and the display panel.

[0014] However, with the increasing design requirements, such as in the design of curved screen modules, medium and large-sized display modules have the need for large curvature bending and long-term bending. Under long-term large curvature bending, a whole PCBA is prone to substrate breakage or poor soldering of soldered components, resulting in performance problems such as PCBA drive signal degradation or even failure.

[0015] Even when using a combination of PCBA and FPC, the connection structure between PCBA and FPC provides new risk points for signal transmission and stress concentration during bending, which may lead to deviations during insertion and failure to meet performance requirements. Furthermore, the entire PCBA design layout needs to be completely readjusted, further extending the design cycle.

[0016] Similarly, in the module design of some foldable screen products, there is also a need for large curvature and long-term bending.

[0017] In view of the considerations and technical needs of solving the above-mentioned technical problems, this application provides a display module and display device that can meet the requirements of long-term use under bending with large curvature and is not prone to performance problems such as drive signal attenuation.

[0018] Figure 1 This invention illustrates an assembly structure for a display module provided in a first aspect embodiment of the present application. Figure 2 This illustration shows a planar unfolded structure of a display module provided in a first aspect embodiment of this application. Figure 3 It shows Figure 1 A schematic diagram of a cross-sectional structure along the AA direction. Figure 4 It shows Figure 1 Another cross-sectional structure diagram along the AA direction.

[0019] Please see Figures 1 to 4 In a first aspect, embodiments of this application provide a display module, including a display panel 100, a flexible ribbon cable 200, and a circuit board assembly 300.

[0020] The display panel 100 includes a flexible substrate, and a flexible cable 200 is connected to one side of the display panel 100.

[0021] The circuit board assembly 300 is located on the backlight side 100a of the display panel 100. The circuit board assembly 300 is connected to the end of the flexible cable 200 away from the display panel 100. The circuit board assembly 300 includes a substrate layer 310 and a device layer 320 stacked along the direction away from the display panel 100. The substrate layer 310 includes at least one planar device area PA and a bending area CA arranged along the first direction X. The substrate layer 310 also includes a body portion 311 and a reinforcing structure 312. The reinforcing structure 312 is at least partially located in the planar device area PA. The device layer 320 includes a circuit element 321 and a circuit trace 322. The circuit element 321 is at least partially located in the planar device area PA. The circuit trace 322 is connected to the circuit element 321 and is at least partially located in the bending area CA.

[0022] At least one planar device region PA in the substrate layer 310 is parallel to the functional plane FP. The display panel 100, the flexible cable 200, and the bending region CA in the substrate layer 310 are at least partially not parallel to the functional plane FP. The functional plane FP is the plane on the side of the reinforcing structure 312 in the planar device region PA that is away from the circuit element 321.

[0023] The display panel 100 uses a flexible substrate, which is generally made of polyimide (PI). It can support the driving circuit structure and light-emitting structure of the display panel 100, and has good flexibility. The display panel 100 can be deformed to a certain extent without affecting normal light output. It is suitable for use in display modules of curved screen products or foldable screen products.

[0024] The display panel 100 includes a side where light-emitting components are arranged, namely the light-emitting side 100b, for emitting light and displaying content; and a side where the circuit board assembly 300 in the display module is arranged, namely the backlight side 100a, for arranging various functional components.

[0025] The flexible flat cable 200 typically uses an FPC, which can place the circuit board assembly 300 on the backlight side 100a of the display panel 100. While maintaining the electrical connection between the circuit board assembly 300 and the display panel 100 by bending itself, it also bends to a certain extent along with the bending direction of the display panel 100. It can adapt to bending in two directions at the same time and maintain stable performance during long-term bending use.

[0026] The substrate layer 310 of the circuit board assembly 300 adopts a design concept that combines the body part 311 and the reinforcing structure 312. The body part 311 adopts a single layer design and usually uses a flexible printed circuit assembly 300 (FPCA). This can avoid the new risk points of deviation, detachment and stress concentration caused by the addition of new plug-in mating in the combination of PCBA+FPC. At the same time, FPCA can be freely bent in accordance with the bending curvature of the display panel 100.

[0027] The reinforcing structure 312 defines the bending resistance of the planar device area PA, so that the circuit element 321 can be in the same plane parallel to the functional plane FP and avoid desoldering. The reinforcing structure 312 is generally made of a rigid material, such as metal sheet or hard plastic. The circuit trace 322 can withstand the bending of the bending area CA without falling off.

[0028] The fact that at least one planar device region PA in the substrate layer 310 is parallel to the functional plane FP should be understood as meaning that the circuit elements 321 in the planar device region PA can be in the same plane parallel to the functional plane FP, thus avoiding desoldering.

[0029] The fact that at least part of the bending area CA in the display panel 100, flexible cable 200 and substrate layer 310 is not parallel to the functional plane FP should be understood as the fact that the bending area CA in the display panel 100, flexible cable 200 and substrate layer 310 has been bent, so that the bending area CA in the display panel 100, flexible cable 200 and substrate layer 310 is not located on the same plane.

[0030] For example, the display module provided in the first aspect embodiment of this application can be applied to curved screen products.

[0031] For example, the display module provided in the first aspect embodiment of this application can be applied to foldable screen products.

[0032] For example, please refer to Figure 3 The display panel 100 can be concave and curved, that is, the center of the display panel 100 is curved from the light-emitting side 100b to the backlight side 100a, and the periphery is curved from the backlight side 100a to the light-emitting side 100b.

[0033] For example, please refer to Figure 4 The display panel 100 can be outwardly curved, that is, the center of the display panel 100 is curved from the backlight side 100a to the light-emitting side 100b, and the periphery is curved from the light-emitting side 100b to the backlight side 100a.

[0034] The display module provided in the first aspect of this application uses a circuit board assembly 300 with a body portion 311 and a reinforcing structure 312. By bending a portion of the body portion 311 and a portion of the circuit traces 322 in the bending area CA, it is possible to maintain stable performance for a long time under large curvature bending and avoid the problem of drive signal attenuation. On the one hand, the circuit board assembly 300 uses a whole layer of body portion 311 to avoid the risk of components falling off due to long-term bending. On the other hand, the reinforcing structure 312 defines the bending resistance of the planar device area PA on the substrate layer 310, so that the circuit element 321 can be in the same plane parallel to the functional plane FP and avoid desoldering.

[0035] Please see Figure 1 In some embodiments, the display panel 100 covers the circuit board assembly 300, and a gap D is formed between the edge of the circuit board assembly 300 and the edge of the display panel 100, the gap D not exceeding 1 mm.

[0036] In these embodiments, the curvature of the display panel 100 is matched with the size of the circuit board assembly 300, enabling a compact and adaptable display module.

[0037] Specifically, the display panel 100 covers the circuit board assembly 300 in the direction of the backlight side 100a, so that the circuit board assembly 300 is completely contained within the projection range of the display panel 100. On the one hand, this effectively shields the circuit elements 321 and circuit traces 322 in the device layer 320 of the circuit board assembly 300, preventing the circuit board assembly 300 from being directly contacted or interfered with by the external environment during the assembly and use of the display module, thus protecting the circuit board assembly 300. On the other hand, the coverage of the circuit board assembly 300 by the display panel 100 also helps to maintain the stability of the relative positional relationship between the functional layers during the overall bending process of the display module, reducing the risk of relative misalignment between the layers due to bending.

[0038] The gap D formed between the edge of the circuit board assembly 300 and the edge of the display panel 100 provides necessary space for the deformation of the circuit board assembly 300 during bending, preventing interference or compression between the edge of the circuit board assembly 300 and the edge of the display panel 100 during bending. This prevents defects such as damage to the substrate layer 310 or breakage of the circuit trace 322 caused by local stress concentration. At the same time, the gap D also provides a certain tolerance space for the assembly alignment of the entire display module within the manufacturing tolerance range, which is beneficial to improving the yield and assembly consistency of the display module.

[0039] The size of the gap D is controlled within a small range. While ensuring the above-mentioned bending release and assembly tolerance functions, it also avoids the gap D being too large, which would cause the edge area of ​​the circuit board assembly 300 to lack effective shielding and affect the overall structural compactness and appearance quality of the module.

[0040] The gap D does not exceed 1 mm. The bending arc length of the display panel 100 matches the size of the circuit board assembly 300. This means that in the bending state, the actual arc length of the display panel 100 along the bending direction and the unfolded size of the circuit board assembly 300 in the same direction are coordinated and consistent. This allows the two to maintain a good fit and correspondence in the direction of the backlight side 100a after bending, avoiding problems such as partial lifting, suspension, or excessive stretching of the flexible ribbon cable 200 caused by size mismatch. This further ensures the structural stability and electrical connection reliability of the display module under long-term use in a large curvature bending state, and realizes the overall compact structure and functional adaptation of the display module.

[0041] For example, whether Figure 3 The bending method shown is still Figure 4 The bending methods shown all have a gap D of no more than 1 mm, and the circuit board assembly 300 can adapt to a variety of different bending design requirements.

[0042] Please see Figures 1 to 4In some embodiments, the planar device region PA includes a first device region PA1 and a second device region PA2. The first device region PA1, the bending region CA, and the second device region PA2 are arranged sequentially along the first direction X. The reinforcing structure 312 includes a first reinforcing part and a second reinforcing part. The first reinforcing part is at least partially located in the first device region PA1, and the second reinforcing part is at least partially located in the second device region PA2.

[0043] The functional plane FP includes a first plane FP1 and a second plane FP2. The first plane FP1 is the plane on the side of the first reinforcement part away from the main body part 311 in the first device area PA1, and the second plane FP2 is the plane on the side of the second reinforcement part away from the main body part 311 in the second device area PA2.

[0044] The first device area PA1 is parallel to the first plane FP1, the second device area PA2 is parallel to the second plane FP2, and the display panel 100, the flexible cable 200 and the bending area CA are at least partially not parallel to the first plane FP1 and at least partially not parallel to the second plane FP2.

[0045] In these embodiments, the planar device area PA is further divided into a first device area PA1 and a second device area PA2 located on both sides of the bending area CA. The area with the highest arch height and greatest risk after the display panel 100 is bent corresponds to the bending area CA. The first device area PA1 and the second device area PA2 are located on both sides, which further ensures the structural stability and electrical connection reliability of the display module when used for a long time under a large curvature bending state.

[0046] The planar device area PA is further subdivided into a first device area PA1 and a second device area PA2 located on both sides of the bending area CA. The three are arranged in sequence along the first direction X, forming a structural pattern with the bending area CA as the center and the first device area PA1 and the second device area PA2 symmetrically distributed on both sides, which corresponds to the area where the display module arches and deforms most significantly after bending.

[0047] When the display module undergoes a large curvature bend, the bending area CA bears the main bending deformation along the first direction X, while the first device area PA1 and the second device area PA2 are respectively moved to both sides of the bending area CA, effectively avoiding the adverse effects of the most severe deformation area on the circuit element 321. The first and second reinforcing parts apply local rigid constraints to the body part 311 in their respective device areas. The first reinforcing part keeps the circuit element 321 in the first device area PA1 stably in the same bearing plane parallel to the first plane FP1, and the second reinforcing part keeps the circuit element 321 in the second device area PA2 stably in the same bearing plane parallel to the second plane FP2. Thus, the circuit elements 321 soldered to the body part 311 in both device areas can maintain good welding structure integrity in the bending state, effectively avoiding the risk of component desoldering or solder joint cracking caused by bending.

[0048] Meanwhile, the main body 311, as an integral flexible substrate connecting the first device area PA1, the bending area CA, and the second device area PA2, eliminates the plug-in fit deviation and stress concentration hazards introduced by the segmented structure at the connection position. The circuit traces 322 in the bending area CA can extend freely with the bending deformation under the support of the main body 311, maintaining continuous conduction during repeated bending without electrical performance problems such as resistance degradation or signal interruption. This further ensures the structural stability and electrical connection reliability of the display module under large curvature bending conditions for a long time.

[0049] For example, whether Figure 3 The bending method shown is still Figure 4 The bending method shown can be applied to designs where the planar device area PA is divided into a first device area PA1 and a second device area PA2, and the bending area CA is located between the two. The circuit board assembly 300 can adapt to a variety of different bending design requirements.

[0050] Please see Figure 1 and Figure 2 In some embodiments, the flexible ribbon cable 200 includes a first ribbon cable 210 and a second ribbon cable 220. The first ribbon cable 210 is connected to the circuit element 321 in the first device area PA1, and the second ribbon cable 220 is connected to the circuit element 321 in the second device area PA2. The distance between the first device area PA1 and the second device area PA2 is greater than the distance between the first ribbon cable 210 and the second ribbon cable 220.

[0051] In these embodiments, the first ribbon cable 210 and the second ribbon cable 220 can independently lead out the drive signals of the circuit elements 321 of the first device area PA1 and the second device area PA2, respectively, avoiding mutual interference. At the same time, the gradually unfolding structural layout from the flexible ribbon cable 200 to the circuit board assembly 300 can form a natural transition bend, avoiding mutual interference and local stacking that could cause compression, resulting in local stress concentration that could lead to performance degradation or even failure.

[0052] The flexible ribbon cable 200 serves as a key intermediate layer connecting the display panel 100 and the circuit board assembly 300. In this embodiment, it is further refined into a first ribbon cable 210 and a second ribbon cable 220 corresponding to the first device area PA1 and the second device area PA2, respectively. Each ribbon cable independently undertakes the signal transmission function of the circuit element 321 in the corresponding device area, so that the driving signals of the first device area PA1 and the second device area PA2 are independently led out through the corresponding ribbon cable, which not only ensures the clarity and integrity of the signal transmission path, but also reduces the risk of mutual interference between the two signals.

[0053] The distance between the first device area PA1 and the second device area PA2 is greater than the distance between the first ribbon cable 210 and the second ribbon cable 220. The first ribbon cable 210 and the second ribbon cable 220 converge at a smaller spacing on the display panel 100 side, while the corresponding first device area PA1 and second device area PA2 are set at a larger spacing on both sides of the bending area CA, thereby forming an unfolding transition relationship of the ribbon cable to the circuit board assembly 300 side.

[0054] This unfolded layout allows the first and second cables 210 and 220 to form smooth bending curves during their bending process, avoiding mutual compression or interference near the bending area CA due to their close proximity, thus reducing the risk of local stress concentration. On the other hand, the unfolded transition provided by the first and second cables 210 and 220 also helps to reasonably distribute the bending strain borne by the two cables when the display module undergoes a large curvature bend, making the cables less prone to fatigue fracture or signal transmission degradation during long-term repeated bending.

[0055] In addition, the first row of cables 210 and the second row of cables 220 establish independent electrical connections with their respective device areas, which helps to achieve accurate alignment and reliable connection during the assembly of the display module, further ensuring the structural stability and electrical connection reliability of the display module under long-term use in a state of large curvature bending.

[0056] For example, whether Figure 3 The bending method shown is still Figure 4The bending method shown is applicable to both the design of the flexible cable 200 being divided into the first cable 210 and the second cable 220, and the circuit board assembly 300 can adapt to a variety of different bending design requirements.

[0057] Please see Figure 1 and Figure 2 In some embodiments, the minimum distance between circuit element 321 and the edge of planar device region PA is greater than or equal to 3 mm.

[0058] In these embodiments, limiting the edge safety distance between circuit element 321 and planar device area PA can further ensure the connection stability of circuit element 321 and avoid problems such as desoldering caused by bending of circuit element 321.

[0059] The arrangement of circuit element 321 in the planar device area PA on the substrate layer 310 needs to maintain a safe distance of not less than a certain limit from the edge of the planar device area PA. The safe distance is limited to restricting the arrangement area of ​​circuit element 321 to the inner central area of ​​the planar device area PA, so that it is sufficiently far away from the boundary edge of the planar device area PA and the bending area CA.

[0060] The bending deformation of the bending region CA will form a stress gradient region near the boundary transitioning to the planar device region PA. The local stress level of the body part 311 in this region during repeated bending over a long period of time is higher than that in the middle region of the planar device region PA. If the circuit element 321 is arranged too close to the edge of the planar device region PA, the circuit element 321 and its welding structure will inevitably be affected by the above-mentioned boundary stress. During long-term use, fatigue damage will gradually accumulate, leading to electrical performance degradation problems such as solder joint cracking, component desoldering, or increased local resistance.

[0061] By specifying that the minimum distance between circuit element 321 and the edge of the planar device area PA is not less than a certain limit, it can be ensured that all circuit elements 321 fall into a stable region far from the influence range of stress gradient, so that the local rigid constraint provided by the reinforcing structure 312 can play a full role, ensuring that the circuit element 321 is always in a stable bearing plane and is not disturbed by bending boundary stress. Thus, during long-term use under large curvature bending conditions, the integrity of the welded structure and the reliability of electrical connection are maintained, and the occurrence of performance problems such as drive signal attenuation is further suppressed.

[0062] Please continue reading. Figure 1 and Figure 2 In some embodiments, the minimum distance between the circuit element 321 and the edge of the bend region CA adjacent to the planar device region PA is greater than or equal to 3 mm.

[0063] In these embodiments, limiting the edge safety distance between circuit element 321 and the bending area CA can further ensure the connection stability of circuit element 321 and avoid problems such as desoldering of circuit element 321 due to bending.

[0064] The adjacent edge between the bending area CA and the planar device area PA is the most mechanically complex position in the entire circuit board assembly 300. The bending area CA bears most of the bending deformation when the display module undergoes a large curvature bend, while the planar device area PA maintains a planar posture due to the rigid constraint of the reinforcing structure 312. The two form a sudden change in stiffness at the adjacent edge, which makes the edge position bear extremely concentrated stress during the bending process, becoming the peak area in the stress distribution of the entire substrate layer 310.

[0065] If the circuit element 321 is positioned too close to the adjacent edge of the bending area CA and the planar device area PA, the circuit element 321 and its welded structure will be directly exposed to the influence range of the peak stress. During the long-term use of the display module with a large curvature bend, fatigue damage will continue to accumulate at the solder joint, eventually leading to the failure of the welded structure and serious performance problems such as component desoldering, solder joint cracking, and even drive signal interruption.

[0066] By specifying that the minimum distance between the circuit element 321 and the adjacent edge of the planar device area PA in the bending area CA is not less than a certain limit, an effective safety isolation can be established for the arrangement position of the circuit element 321 within the planar device area PA. This ensures that all circuit elements 321 fall into a stable position far away from the peak stress influence area of ​​the adjacent edge, so that the local rigid protection provided by the reinforcing structure 312 fully covers all circuit elements 321. This ensures that each circuit element 321 is always in a load-bearing plane with uniform stress and stable posture under bending conditions. Thus, during long-term use under large curvature bending conditions, the integrity of the welded structure and the reliability of the electrical connection are maintained, and the occurrence of performance problems such as drive signal attenuation is effectively suppressed.

[0067] Please continue reading. Figure 1 and Figure 2 In some embodiments, the substrate layer 310 further includes a bonding region BA, which is located on at least one side of the planar device region PA along the second direction Y, where the first direction X intersects the second direction Y.

[0068] Device layer 320 also includes bonding terminal 323, which is at least partially located in bonding region BA and connected to circuit element 321 via circuit trace 322. Bonding region BA is at least partially not parallel to functional plane FP.

[0069] In these embodiments, the electrical environment and component layout within the bonding area BA are relatively simple. The bonding area BA and the bonding terminal 323 are bent together with the flexible cable 200, which can also ensure the integrity of the welded structure and the reliability of the electrical connection during long-term use under a large curvature bending state.

[0070] The bonding area BA is arranged along the second direction Y on at least one side of the planar device area PA. The design that the first direction X intersects with the second direction Y makes the extension direction of the bonding area BA different from the extension direction of the bending area CA, thereby forming a clear functional partition layout in the planar unfolded state, which facilitates the rational spatial planning and assembly operation of the entire circuit board assembly 300.

[0071] The bonding terminal 323 serves as a key interface structure for establishing electrical interconnection between the circuit board assembly 300 and the display panel 100. It is connected to the circuit element 321 in the planar device area PA through the circuit trace 322 and undertakes the bidirectional transmission function of drive signals between the circuit board assembly 300 and the display panel 100.

[0072] The distribution density of the bonding terminals 323 in the bonding area BA is relatively limited compared to the arrangement density of the circuit elements 321. The electrical environment and component layout are relatively simple, and there are no additional constraints on bending deformation caused by a large number of soldered components. Therefore, the bonding area BA has good follow-up bending capability in structure.

[0073] The bonding area BA is at least partially not parallel to the functional plane FP, which means that the bonding area BA can deform accordingly with the bending direction of the flexible cable 200, and adapt to the bending direction of the display panel 100 on the backlight side 100a together with the flexible cable 200. This allows the bonding terminal 323 to maintain stable electrical contact with the flexible cable 200 even when bent, without affecting the signal transmission quality due to partial warping or misalignment of the bonding area BA.

[0074] Because the bonding area BA bends along with the flexible cable 200, the stress distribution of the circuit traces 322 within the bonding area BA during bending is relatively uniform, making it less prone to local stress concentration. As a result, even under conditions where the display module is subjected to a large curvature bend for an extended period, the connection structure between the bonding terminal 323 and the flexible cable 200 can still maintain good contact stability and conductivity reliability. This further ensures the structural stability and electrical connection reliability of the display module under a large curvature bend for an extended period, effectively suppressing performance problems such as drive signal attenuation.

[0075] Please continue reading. Figure 1 and Figure 2 In some embodiments, the minimum distance between the circuit element 321 and the edge of the bonding area BA that is adjacent to the planar device area PA is greater than or equal to 10 mm.

[0076] In some embodiments, the circuit element 321 is spaced at a safe distance from the bonding area BA to prevent the bonding area BA and the bonding terminals 323 in the bonding area BA from bending with the flexible cable 200, and to prevent mutual interference between the circuit element 321 in the planar device area PA located on the same plane parallel to the functional plane FP and the rigid reinforcing structure 312, thereby further ensuring the structural stability and electrical connection reliability of the display module under long-term use in a large curvature bending state.

[0077] During the bending process of the display module, the bonding area BA undergoes corresponding bending deformation along with the flexible cable 200, while the planar device area PA maintains a stable planar posture under the rigid constraint of the reinforcing structure 312. The bonding area BA belongs to the flexible functional area that follows the bending, while the planar device area PA belongs to the stable load-bearing area that maintains rigidity. The boundary between the two will inevitably form an obvious deformation transition gradient in the bending state.

[0078] If the circuit element 321 is positioned too close to the adjacent edge of the bonding area BA and the planar device area PA, the displacement and deformation of the bonding area BA and its internal bonding terminals 323 during the bending process of the flexible cable 200 will exert local squeezing or pulling effects on the adjacent circuit element 321 and the reinforcing structure 312. On the one hand, this will interfere with the rigidity retention effect of the reinforcing structure 312 on the planar device area PA, causing the bearing plane where the circuit element 321 is located to tilt or warp locally, leading to the risk of component desoldering. On the other hand, the additional stress caused by the deformation of the bonding area BA may also be transmitted to the solder joints of the adjacent circuit element 321 through the circuit trace 322, gradually accumulating damage during repeated bending over a long period of time, leading to failure of the soldered structure.

[0079] By specifying that the minimum distance between the adjacent edges of the circuit element 321 and the bonding area BA and the planar device area PA is not less than a certain limit, a sufficiently wide isolation buffer is established within the planar device area PA for the placement of the circuit element 321. This ensures that the influence range of the bending deformation of the bonding area BA does not extend to the area where the circuit element 321 is located, thus forming sufficient spatial isolation between the rigid state within the planar device area PA and the follow-up bending state of the bonding area BA. This ensures the integrity of the welding structure of the circuit element 321 during long-term use under a large curvature bending state and effectively suppresses performance problems such as drive signal attenuation.

[0080] In some embodiments, the difference in elastic modulus between the body portion 311 and the reinforcing structure 312 does not exceed 100 gigapascals.

[0081] In these embodiments, the difference in elastic modulus between the body portion 311 and the reinforcing structure 312 does not exceed 100 gigapascals (GPa), and the difference in elastic modulus between the body portion 311 and the reinforcing structure 312 is kept within a suitable range, further avoiding breakage at the junction of the planar device area PA and the bending area CA.

[0082] The body 311 typically adopts a multilayer flexible material stacked structure based on polyimide (PI), with a relatively low overall elastic modulus. The reinforcing structure 312 provides local rigid constraints for the planar device area PA, and there is a certain degree of difference in elastic modulus between the two.

[0083] When the difference in elastic modulus is too large, a sudden change in stiffness will occur in the substrate layer 310 at the junction of the planar device area PA and the bending area CA: the planar device area PA side has a higher overall stiffness due to the presence of the reinforcing structure 312, while the bending area CA side has only the flexible body part 311 and has a lower stiffness. The stiffness mismatch on both sides causes the junction edge to bear extremely concentrated local bending stress during the bending process. With the accumulation of bending times, fatigue damage at this location will develop rapidly, eventually leading to the fracture failure of the substrate body part 311 at the junction.

[0084] By limiting the difference in elastic modulus between the main body 311 and the reinforcing structure 312 to a reasonable range, the abrupt change in stiffness between the two can be effectively mitigated, making the stiffness change during the transition from the planar device area PA to the bending area CA more gradual. This controls the stress concentration at the interface within a safe range that the material can withstand, delays the initiation and propagation speed of fatigue cracks, and further ensures the structural integrity and electrical connection reliability of the display module under long-term use in a large curvature bending state.

[0085] In some embodiments, the reinforcing structure 312 is embedded within the body portion 311.

[0086] In these embodiments, the reinforcing structure 312 is not attached to the outer surface of the body portion 311, but is integrated into the internal structure of the body portion 311 in an embedded manner, so that the reinforcing structure 312 and the body portion 311 form an integrated covering relationship.

[0087] The embedded design enables the reinforcement structure 312 to form a local rigid skeleton inside the body 311, which can provide stable rigid support for the planar device area PA from the inside of the body 311 without the need for additional external fixing structures.

[0088] On the one hand, the embedded design completely encloses the interface between the reinforcing structure 312 and the main body 311 inside the main body 311, avoiding the risk that the reinforcing structure 312 will lose its rigid constraint effect due to interface peeling or displacement during external bending, thus ensuring the continuous and effective protection of the planar device area PA by the reinforcing structure 312. On the other hand, the embedded design makes the overall thickness of the circuit board assembly 300 more controllable, reducing the possibility of additional stress concentration introduced during bending due to the sudden change in local thickness caused by the external reinforcing structure 312, thereby further ensuring the structural stability and electrical connection reliability of the display module under long-term use under large curvature bending conditions.

[0089] In some embodiments, the body portion 311 includes multiple layers of flexible material, and a connecting adhesive layer is disposed between adjacent flexible material layers.

[0090] In these embodiments, the body part 311 adopts a multi-layer flexible material stacked structure. The flexible material layers are bonded to each other through a connecting adhesive layer, so that the multi-layer structure maintains a coordinated deformation response during the overall bending process without interlayer misalignment or delamination.

[0091] The combined action of each flexible material layer and the connecting adhesive layer in the multi-layer structure allows for reasonable control of the bending neutral layer position of the main body 311 in the bending zone CA, reducing the ultimate strain borne by each layer of material during bending and effectively slowing down the accumulation rate of fatigue damage in the flexible material layers during long-term repeated bending. This maintains the integrity of the overall structure of the main body 311 and the reliability of the electrical connection between each layer during long-term use under a large curvature bending state.

[0092] For example, the flexible material layer has four layers and the adhesive layer has three layers.

[0093] In some embodiments, the reinforcing structure 312 comprises a stainless steel sheet material, and the thickness of the reinforcing structure 312 includes 0.15 mm to 0.25 mm.

[0094] In these embodiments, the stainless steel sheet material has excellent bending stiffness and structural strength, which can provide sufficient rigid constraints for the planar device area PA under relatively small thickness conditions. This ensures that the circuit elements 321 in the planar device area PA remain stably in the same bearing plane parallel to the functional plane FP when the display module undergoes a large curvature bend, effectively avoiding the risk of component desoldering.

[0095] At the same time, stainless steel sheet material has excellent corrosion resistance and dimensional stability, and its material properties are not prone to deterioration during long-term use, which can continuously ensure the rigid protection effect of the reinforcing structure 312 on the planar device area PA.

[0096] In terms of thickness design, the reasonable limitation of the thickness of the reinforcing structure 312 takes into account the balance between rigidity requirements and overall thickness control: if the thickness is too small, it will be difficult to provide sufficient bending support; if the thickness is too large, it will increase the overall thickness of the display module and may introduce excessive stress change at the CA boundary of the bending zone. The appropriate thickness range ensures that the reinforcing structure 312 can give full play to the rigid constraint function without adversely affecting the overall bending performance of the display module, and further ensures the structural stability of the display module under long-term use in a large curvature bending state.

[0097] In some embodiments, the display module further includes a driver chip 400, which is disposed on the side of the flexible cable 200 away from the display panel 100.

[0098] In these embodiments, the display module adopts a chip-on-film (COF) arrangement where the driver chip 400 is located on the flexible cable 200. This can further narrow the bezel of the display module while ensuring the structural stability and electrical connection reliability of the display module during long-term use under large curvature bending conditions.

[0099] The driver chip 400 is integrated onto the flexible ribbon cable 200 and located on the side of the flexible ribbon cable 200 away from the display panel 100. This allows the driver chip 400 to bend along with the flexible ribbon cable 200 to the backlight side 100a of the display panel 100, thereby completely removing the space occupied by the driver chip 400 from the light-emitting side 100b or the edge area of ​​the display panel 100. Compared with the traditional packaging method where the driver chip 400 is directly fixed to the glass side of the display panel 100, the COF packaging method eliminates the need to reserve extra space for the driver chip 400 and its related traces at the edge of the light-emitting side 100b of the display panel 100. This reduces the bezel width of the display module and helps achieve a higher screen-to-body ratio design goal.

[0100] Meanwhile, the arrangement of integrating the driver chip 400 onto the flexible cable 200 also allows the signal transmission path between the driver chip 400 and the circuit board assembly 300 to be smoothly connected through the flexible cable 200. While ensuring the integrity of the drive signal transmission, it works in conjunction with the design scheme of the integrated body 311 and the reinforcement structure 312 of the circuit board assembly 300 in this application to further ensure the structural stability and electrical connection reliability of the display module under long-term use in a large curvature bending state, so that the display module can simultaneously achieve a narrow bezel design and high reliability bending performance.

[0101] Figure 5 The overall structure of a display device 500 provided in a second aspect embodiment of this application is shown.

[0102] Secondly, embodiments of this application provide a display device 500, including the display module provided in any of the first aspects of this application.

[0103] The display device 500 provided in the second aspect embodiment of this application, since it includes the display module provided in any of the first aspect embodiments of this application, has the beneficial effects of the display module provided in any of the first aspect embodiments of this application, which will not be repeated here.

[0104] The display device 500 in this application embodiment includes, but is not limited to, mobile phones, personal digital assistants, tablet computers, e-books, televisions, access control systems, smart landline phones, control consoles, and other devices with display functions.

[0105] The display device 500 can be any device with a display function, such as mobile devices such as mobile phones, tablets, laptops, handheld computers, in-vehicle electronic devices, wearable devices, ultra-mobile personal computers (UMPCs), netbooks, or personal digital assistants (PDAs), as well as non-mobile devices such as personal computers (PCs), televisions (TVs), ATMs, or self-service machines.

[0106] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A display module, characterized in that, include: Display panel, including flexible substrate; A flexible ribbon cable is connected to one side of the display panel; A circuit board assembly is located on the backlight side of the display panel. The circuit board assembly is connected to one end of the flexible cable away from the display panel. The circuit board assembly includes a substrate layer and a device layer stacked along the direction away from the display panel. The substrate layer includes at least one planar device area and a bending area arranged along a first direction. The substrate layer also includes a body portion and a reinforcing structure. The reinforcing structure is at least partially located in the planar device area. The device layer includes circuit elements and circuit traces. The circuit elements are at least partially located in the planar device area. The circuit traces are connected to the circuit elements and are at least partially located in the bending area. At least one of the planar device areas in the substrate layer is parallel to the functional plane, and at least part of the display panel, the flexible cable, and the bending area in the substrate layer are not parallel to the functional plane. The functional plane is the plane on the side of the reinforcing structure in the planar device area that is away from the circuit element.

2. The display module according to claim 1, characterized in that, The display panel covers the circuit board assembly, and a gap is formed between the edge of the circuit board assembly and the edge of the display panel, the gap not exceeding 1 mm.

3. The display module according to claim 2, characterized in that, The planar device area includes a first device area and a second device area. The first device area, the bending area, and the second device area are arranged sequentially along the first direction. The reinforcing structure includes a first reinforcing part and a second reinforcing part. The first reinforcing part is at least partially located in the first device area, and the second reinforcing part is at least partially located in the second device area. The functional plane includes a first plane and a second plane. The first plane is the plane on the side of the first reinforcing part away from the main body in the first device area, and the second plane is the plane on the side of the second reinforcing part away from the main body in the second device area. The first device area is parallel to the first plane, the second device area is parallel to the second plane, and the display panel, the flexible cable, and the bending area are at least partially not parallel to the first plane and at least partially not parallel to the second plane.

4. The display module according to claim 3, characterized in that, The flexible flat cable includes a first flat cable and a second flat cable. The first flat cable is connected to the circuit element in the first device area, and the second flat cable is connected to the circuit element in the second device area. The distance between the first device area and the second device area is greater than the distance between the first flat cable and the second flat cable.

5. The display module according to claim 1, characterized in that, The minimum distance between the circuit element and the edge of the planar device area is greater than or equal to 3 mm.

6. The display module according to claim 5, characterized in that, The minimum distance between the circuit element and the edge adjacent to the bending area and the planar device area is greater than or equal to 3 mm.

7. The display module according to claim 5, characterized in that, The substrate layer further includes a bonding region located on at least one side of the planar device region along a second direction, wherein the first direction intersects the second direction; The device layer also includes bonding terminals, which are at least partially located in the bonding area and connected to the circuit element through the circuit traces. The bonding area is at least partially not parallel to the functional plane.

8. The display module according to claim 7, characterized in that, The minimum distance between the circuit element and the edge of the bonding area adjacent to the planar device area is greater than or equal to 10 mm.

9. The display module according to claim 1, characterized in that, The difference in elastic modulus between the main body and the reinforcing structure does not exceed 100 gigapascals.

10. The display module according to claim 9, characterized in that, The reinforcing structure is embedded within the body portion.

11. The display module according to claim 9, characterized in that, The main body includes multiple layers of flexible material, and a connecting adhesive layer is provided between adjacent flexible material layers.

12. The display module according to claim 9, characterized in that, The reinforcing structure comprises a stainless steel sheet material, and the thickness of the reinforcing structure ranges from 0.15 mm to 0.25 mm.

13. The display module according to claim 1, characterized in that, The display module also includes a driver chip, which is disposed on the side of the flexible cable away from the display panel.

14. A display device, characterized in that, The display module includes any one of claims 1 to 13.

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