An adhesive layer, a preparation method thereof, a flexible display panel, and a display device

Abstract

This application relates to the field of display technology, disclosing an adhesive layer and its preparation method, a flexible display panel, and a display device. The adhesive layer includes: a first flexible layer, a heat dissipation layer, and a second flexible layer sequentially disposed therefrom; wherein the heat dissipation layer includes a graphene layer and a step adhesive layer; the first flexible layer has a first surface connected to the heat dissipation layer; the graphene layer has a second surface connected to the first flexible layer; the area of ​​the second surface is smaller than the area of ​​the first surface; the step adhesive layer is distributed on the outer periphery of the graphene layer such that the sum of the projected area of ​​the step adhesive layer on the first surface and the area of ​​the second surface equals the area of ​​the first surface. Applying this flexible display panel can effectively improve the heat dissipation uniformity of the flexible display panel.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to an adhesive layer for a flexible display panel, a method for preparing the same, a flexible display panel, and a display device. Background Technology

[0002] Flexible OLED display panels, as an important component of automotive rollable OLED display panels, can be unfolded to provide a large display area when needed, and rolled up for storage to save space when not in use.

[0003] In traditional automotive OLED display panels, a common approach is to use a metal plate (such as an aluminum plate) on the back of the flexible display panel. This metal plate serves two purposes: it acts as a structural support to protect the display module, and it also has excellent thermal conductivity, allowing the heat generated by the OLED flexible display panel during operation to be quickly and evenly distributed throughout the entire module area, effectively avoiding problems such as uneven display and lifespan reduction caused by concentrated hot spots.

[0004] However, the aforementioned metal plate solution is unsuitable for automotive-grade roll-up OLED display panels due to their rigidity. Roll-up products require the display module to be able to repeatedly roll and slide. A common solution is to design specific perforated patterns on the support to achieve flexibility. However, perforated patterns disrupt the continuous heat conduction path of the metal material, leading to a significant increase in the overall thermal resistance of the support. This prevents the effective uniformization of heat generated locally within the display module, resulting in localized high-temperature issues that affect display performance, cause display stuttering, and reduce product reliability. Summary of the Invention

[0005] This application discloses an adhesive layer for a flexible display panel and its preparation method, a flexible display panel, and a display device, which are used to improve the heat dissipation uniformity of the flexible display panel.

[0006] To achieve the above objectives, this application provides the following technical solution: In a first aspect, this application provides an adhesive layer for a flexible display panel, comprising: a first flexible layer, a heat dissipation layer, and a second flexible layer disposed sequentially; The heat dissipation layer includes a graphene layer and a step adhesive layer. The first flexible layer has a first surface connected to the heat dissipation layer, and the graphene layer has a second surface connected to the first flexible layer. The area of ​​the second surface is smaller than the area of ​​the first surface. The step adhesive layer is distributed on the outer periphery of the graphene layer so that the sum of the projected area of ​​the step adhesive layer on the first surface and the area of ​​the second surface is equal to the area of ​​the first surface.

[0007] In some embodiments, the second flexible layer is used to connect the support member; The first flexible layer includes a first pressure-sensitive adhesive layer, a polyester film layer and a second pressure-sensitive adhesive layer arranged sequentially, and the second pressure-sensitive adhesive layer is connected to the heat dissipation layer.

[0008] In some embodiments, the thickness of the first pressure-sensitive adhesive layer is between 10 μm and 20 μm; The thickness of the polyester film layer is between 10μm and 20μm; The thickness of the second pressure-sensitive adhesive layer is between 10μm and 20μm.

[0009] In some embodiments, the modulus of the first flexible layer is less than 1 MPa. And / or, The modulus of the second flexible layer is less than 1 MPa.

[0010] In some embodiments, the thickness of the graphene layer is between 30 μm and 150 μm.

[0011] In some embodiments, the second flexible layer is used to connect the support member, and the second flexible layer is provided with vent holes, which are located near the edge of the second flexible layer.

[0012] In some embodiments, the center point of the graphene layer coincides with the center point of the first flexible layer, and the step adhesive layer has a ring structure, which wraps around the circumferential outer side of the graphene layer.

[0013] In some embodiments, the graphene layer includes a first portion and a second portion spaced apart; The first flexible layer includes a first side and a second side disposed opposite to each other, with the first part disposed close to the first side and the second part disposed close to the second side; The step adhesive layer includes a main structure and an annular structure. The main structure includes a first notch and a second notch. The first notch is correspondingly provided to the first part and is used to accommodate the first part. The second notch is correspondingly provided to the second part and is used to accommodate the second part. The ring structure wraps around the circumferential outer side of the main structure, the first part, and the second part.

[0014] Secondly, this application provides a method for preparing an adhesive layer for a flexible display panel, comprising: Prepare the first flexible layer; A step adhesive layer is laminated onto the first flexible layer; A graphene layer is composited on a first flexible layer, wherein the step adhesive layer and the graphene layer have the same thickness to form a heat dissipation layer; A second flexible layer is laminated on the side of the heat dissipation layer opposite to the first flexible layer.

[0015] In some embodiments, prior to the step of laminating a second flexible layer onto the side of the heat dissipation layer opposite to the first flexible layer, the method further includes: Vent holes are provided on the second flexible layer according to the curling position of the flexible display panel.

[0016] Thirdly, this application provides a flexible display panel, including: a flexible display module and a support member; An adhesive layer, which is the adhesive layer of any of the above embodiments, is used to bond the flexible display module to the support member.

[0017] Fourthly, this application provides a display device including the aforementioned flexible display panel.

[0018] The beneficial effects of this application are as follows: This application provides an adhesive layer for a flexible display panel, comprising: a first flexible layer, a heat dissipation layer, and a second flexible layer sequentially disposed. The heat dissipation layer includes a graphene layer and a step adhesive layer. The graphene layer has a high thermal conductivity, which can quickly and evenly dissipate the heat generated during the operation of the flexible display panel, achieving a uniform heat dissipation effect and preventing excessively high local temperatures in the flexible display panel, thereby ensuring the stability of the flexible display panel's operation. The step adhesive layer is distributed on the outer periphery of the graphene layer, that is, filling around the graphene layer. The step adhesive can surround the edge of the graphene layer, preventing the edge of the graphene from peeling off from the first or second flexible layer when the flexible display panel is subjected to sliding force. This application improves the heat dissipation effect of the flexible display panel by setting a graphene layer, and at the same time, the step adhesive layer protects the graphene layer, reducing the risk of graphene layer lifting and peeling. In addition, the step adhesive layer can make up for the area difference between the graphene layer and the first flexible layer, so that the second flexible layer can be smoothly attached to the heat dissipation layer. This gives the flexible display panel both the mechanical properties to achieve winding and the high thermal conductivity for rapid heat dissipation, which helps to improve the operational stability of the vehicle-mounted rollable OLED display device. Attached Figure Description

[0019] Figure 1 A cross-sectional view of the adhesive layer of a flexible display panel provided in an embodiment of this application; Figure 2 for Figure 1 A schematic diagram of the decomposed structure; Figure 3 A cross-sectional view of the first flexible layer provided in an embodiment of this application; Figure 4 This is a schematic diagram of the distribution of the graphene layer provided in the embodiments of this application; Figure 5 A schematic diagram showing the distribution of the graphene layer in the adhesive layer of a flexible display panel, provided for another embodiment of this application; Figure 6 A schematic diagram illustrating the variation of strain as modulus in each layer of the adhesive layer provided in the embodiments of this application; Figure 7 This is a surface view of the flexible display panel provided in an embodiment of this application.

[0020] Figure label: 10. Adhesive layer; 20. Flexible display panel; 100. First flexible layer; 110. First pressure-sensitive adhesive layer; 120. Polyester film layer; 130. Second pressure-sensitive adhesive layer; 200. Heat dissipation layer; 210. Graphene layer; 211. First part; 212. Second part; 220. Step adhesive layer; 221. Main structure; 2211. First notch groove; 2212. Second notch groove; 222. Annular structure; 300. Second flexible layer; 310. Vent hole; 400. Flexible display module. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application. In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone.

[0022] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0023] With the development of automotive intelligence and interior integration, in-vehicle display devices are evolving towards larger sizes, irregular shapes, and deformability. Among them, in-vehicle rollable OLED display panels, as an emerging product form, can be unfolded to provide a large display area when needed, and rolled up for storage to save space when not in use.

[0024] In traditional automotive OLED display panels, to ensure heat dissipation performance and structural strength, a metal plate (such as an aluminum plate) is typically used on the back of the flexible display panel. This metal plate serves two purposes: firstly, it acts as a structural support to protect the display module; secondly, its excellent lateral thermal conductivity allows the heat generated by the OLED module during operation to be quickly and evenly distributed throughout the entire module area, effectively avoiding problems such as uneven display and lifespan degradation caused by concentrated hotspots.

[0025] However, the aforementioned solid metal plate solution is unsuitable for automotive-grade roll-up OLED display panels due to its rigidity. Roll-up products require the display module to be able to repeatedly roll and slide, therefore its back panel structure must employ a bendable support design. A common solution is to design specific perforated patterns on the support to achieve flexibility. However, while this pattern structure provides bending capability, it disrupts the continuous heat conduction path of the metal material, leading to a significant increase in the overall thermal resistance of the support. This prevents the effective uniformization of localized heat generated by the display module, resulting in localized high-temperature problems that severely affect display performance and product reliability.

[0026] In view of this, this application provides a flexible display panel suitable for heat dissipation solutions of automotive sliding OLED display devices. While meeting the reliability requirements of sliding, it has good heat dissipation capabilities to solve the technical problems of high thermal resistance and difficulty in eliminating local hot spots in existing flexible support components.

[0027] like Figures 1 to 2 As shown, this application embodiment provides an adhesive layer 10 for a flexible display panel 20, including: a first flexible layer 100, a heat dissipation layer 200 and a second flexible layer 300 disposed sequentially.

[0028] The heat dissipation layer 200 is sandwiched between the first flexible layer 100 and the second flexible layer 300. The first flexible layer 100, the heat dissipation layer 200, and the second flexible layer 300 form a sandwich-like structure.

[0029] In some embodiments, the first flexible layer 100 is used to bond to the flexible display module 400, and the second flexible layer 300 is used to bond to the connector. That is, the adhesive layer 10 can bond the flexible display module 400 to the support.

[0030] The heat dissipation layer 200 includes a graphene layer 210 and a step adhesive layer 220. The first flexible layer 100 has a first surface connected to the heat dissipation layer 200, and the graphene layer 210 has a second surface connected to the first flexible layer 100. The area of ​​the second surface is smaller than the area of ​​the first surface. The step adhesive layer 220 is distributed on the outer periphery of the graphene layer 210 such that the sum of the projected area of ​​the step adhesive layer 220 on the first surface and the area of ​​the second surface is equal to the area of ​​the first surface.

[0031] In the above structure, the graphene layer 210 has a high thermal conductivity, which can quickly and evenly dissipate the heat generated by the flexible display panel 20 during operation, achieving a uniform heat dissipation effect and preventing excessively high local temperatures in the flexible display panel 20, thereby ensuring the stability of the flexible display panel 20 during operation. The step adhesive layer 220 is distributed on the outer periphery of the graphene layer 210, that is, filling around the graphene layer 210. The step adhesive can surround the edge of the graphene layer 210, preventing the edge of the graphene from peeling off from the first flexible layer 100 or the second flexible layer 300 when the flexible display panel 20 is subjected to sliding force. In addition, since the graphene layer 210 has a certain thickness, its edge forms a step with the surface of the first flexible layer 100. The step adhesive layer 220 fills around the graphene, making the upper surface of the entire heat dissipation layer 200 (the surface in contact with the second flexible layer 300) a flat plane, reducing the risk of air bubbles forming when the second flexible layer 300 is adhered.

[0032] This application improves the heat dissipation effect of the flexible display panel 20 by setting a graphene layer 210, and at the same time, it protects the graphene layer 210 by setting a step adhesive layer 220, reducing the risk of edge lifting and peeling of the graphene layer 210. In addition, the step adhesive layer 220 can make up the area difference between the graphene layer 210 and the first flexible layer 100, so that the second flexible layer 300 can be smoothly attached to the heat dissipation layer 200. This gives the flexible display panel 20 both the mechanical properties for winding and the high thermal conductivity for rapid heat dissipation, which helps to improve the operational stability of the automotive roll-up OLED display device.

[0033] Specifically, such as Figure 4 As shown, the center point of the graphene layer 210 coincides with the center point of the first flexible layer 100, and the step adhesive layer 220 is a ring structure 222, which wraps around the circumferential outer side of the graphene layer 210.

[0034] Furthermore, such as Figure 3 As shown, the first flexible layer 100 includes a first pressure-sensitive adhesive layer 110 (first PSA layer, Pressure Sensitive Adhesive), a polyester film layer 120 (PET layer, Polyethyleneterephthalate), and a second pressure-sensitive adhesive layer 130 (second PSA layer, Pressure Sensitive Adhesive) arranged sequentially, and the second pressure-sensitive adhesive layer 130 is connected to the heat dissipation layer 200.

[0035] The polyester film layer 120 has high tensile modulus and dimensional stability. Adding the polyester film layer 120 to the first flexible layer 100 can reduce the risk of tensile deformation of the first flexible layer 100 under stress, thereby ensuring that the entire first flexible layer 100 can be precisely cut, aligned, and bonded.

[0036] Furthermore, the thickness tolerance of the polyester film layer 120 is extremely small (typically within ±1 μm), ensuring that the total thickness of the entire first flexible layer 100 remains stable at a predetermined value. Uneven thickness can lead to optical path differences, affecting display performance. Therefore, ensuring the uniformity of the total thickness of the first flexible layer 100 is beneficial for improving the optical display performance of optical display devices.

[0037] The second pressure-sensitive adhesive layer 130 can be directly connected to the heat dissipation layer 200. Due to the characteristics of the pressure-sensitive adhesive, only pressure needs to be applied when the heat dissipation layer 200 is pasted to achieve the bonding and composite of the second pressure-sensitive adhesive layer 130 and the heat dissipation layer 200, thereby facilitating the rapid connection between the first flexible layer 100 and the heat dissipation layer 200.

[0038] In some embodiments, the thickness of the first pressure-sensitive adhesive layer 110 is between 10 μm and 20 μm. The thickness of the first pressure-sensitive adhesive layer 110 can be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm.

[0039] The thickness of the polyester film layer 120 is between 10μm and 20μm. The thickness of the polyester film layer 120 can be 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, or 20μm.

[0040] The thickness of the polyester film layer 120 is between 10μm and 20μm. The thickness of the second pressure-sensitive adhesive layer 130 is 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, or 20μm.

[0041] Therefore, the thickness of the entire first flexible layer 100 can be between 30μm and 60μm. This arrangement ensures that the total thickness of the first flexible layer 100 does not exceed 60μm. For automotive sliding OLED products, a smaller thickness helps ensure the bending performance of the display panel. Furthermore, controlling the total thickness of the first flexible layer 100 to the micrometer level results in a lower total thermal resistance, allowing heat to be quickly transferred from the display layer to the graphene layer 210. Thus, limiting the thickness of all three layers of the first flexible layer 100 to the range of 10μm-20μm allows the first flexible layer to balance adhesion reliability, heat transfer efficiency, operational rigidity, and bending flexibility, making it more suitable for automotive sliding OLED display applications.

[0042] For example, the thickness of the first pressure-sensitive adhesive layer 110 is 15 μm, the thickness of the polyester film layer 120 is 15 μm, and the thickness of the second pressure-sensitive adhesive layer 130 is 15 μm.

[0043] In some embodiments, the modulus of the first flexible layer 100 is less than 1 MPa. In automotive roll-up products, the entire display device is a multi-layered composite structure. It contains both brittle graphene layers 210 and rigid pattern supports. When the flexible display panel is rolled up, the layers experience varying degrees of stretching or compression due to their different bending radii. If the layers are rigidly connected, the interlayer shear stress will be very high, easily leading to cracking of the graphene layer 210 or delamination at the interface. The modulus of the first flexible layer 100 is <1 MPa, giving it a flexible buffering effect.

[0044] When the heat dissipation layer 200 and the first flexible layer 100 undergo a slight relative displacement during bending, the first flexible layer 100 can absorb this displacement difference through its own deformation. As a result, the graphene layer 210 avoids bearing large stresses from other layers, thereby significantly improving the roll-up life.

[0045] It should also be noted that the first flexible layer 100 needs to have an extremely low modulus (<1MPa) while also serving the functions of bonding, support, and even partial heat transfer. If the first flexible layer 100 only consists of pressure-sensitive adhesive, although its bending performance can be guaranteed, its support, strength, and thermal conductivity will all be reduced. Therefore, a high-modulus polyester film layer (PET layer) is set in the middle of the first flexible layer 100. This extremely thin polyester film layer can improve the support, strength, and thermal conductivity of the first flexible layer 100. At the same time, the two sides of the polyester film layer are wrapped by the low-modulus pressure-sensitive adhesive layer. When the first flexible layer 100 is bent as a whole, the contribution of the high modulus of the polyester film layer to the overall bending stiffness is greatly reduced due to its extreme thinness (10-20μm). The equivalent modulus of the first flexible layer 100 can be less than 1MPa, achieving overall flexibility and local support. The middle PET layer provides stiffness during lamination (for ease of handling), but in the final product, it is encased between the first and second pressure-sensitive adhesive layers 130, without affecting the overall low modulus properties.

[0046] In some embodiments, the structure, material, and modulus of the second flexible layer 300 can be the same as those of the first flexible layer 100. That is, the second flexible layer 300 also includes a first pressure-sensitive adhesive layer 110, a polyester film layer 120, and a second pressure-sensitive adhesive layer 130 disposed sequentially. The first pressure-sensitive adhesive layer 110 of the second flexible layer 300 is connected to the heat dissipation layer 200, and the second pressure-sensitive adhesive layer 130 is connected to the support member. The modulus of the second flexible layer 300 is also less than 1 MPa.

[0047] Furthermore, such as Figure 6 As shown, the dashed line represents the strain curve of the first flexible layer 100, the heat dissipation layer 200, and the second flexible layer 300 when the modulus of the first flexible layer 100 and the second flexible layer 300 is 1 MPa. The solid line represents the strain curve of the first flexible layer 100, the heat dissipation layer 200, and the second flexible layer 300 when the modulus of the first flexible layer 100 and the second flexible layer 300 is 2 MPa. Figure 6 It is evident that when the modulus of the first flexible layer 100 and the second flexible layer 300 decreases from 2 MPa to 1 MPa, the strain of the heat dissipation layer 200 (mainly the graphene layer 210) decreases significantly, effectively reducing the probability of cracking or peeling of the graphene layer 210. The significant decrease in strain of the second flexible layer 300 also improves the lifespan of the flexible display panel 20. The strain of the first flexible layer 100 does not change much, but remains at a safe level. Therefore, keeping the modulus of the first flexible layer 100 and the second flexible layer 300 below 1 MPa allows for the full utilization of their high thermal conductivity and heat dissipation function while ensuring the integrity of the graphene structure, thus simultaneously meeting the dual requirements of automotive sliding products for sliding reliability and heat dissipation performance.

[0048] In some embodiments, the thickness of the graphene layer 210 is between 30 μm and 150 μm. If the thickness of the graphene layer 210 is less than 30 μm, the thermal diffusion capacity and structural strength of the graphene layer 210 will decrease. If the thickness of the graphene layer 210 is greater than 150 μm, the excessive thickness of the graphene layer 210 will lead to increased bending stress, and will also increase the overall thickness and processing cost of the flexible display panel 20. Setting the thickness of the graphene layer 210 between 30 μm and 150 μm can improve the heat dissipation uniformity of the flexible display panel 20. At the same time, in conjunction with the low elastic modulus of the first flexible layer 100 and the second flexible layer 300, it can improve the sliding reliability during bending, thus meeting the dual requirements of sliding reliability and heat dissipation effect for automotive sliding products.

[0049] like Figure 1 As shown, in some embodiments, since the second flexible layer 300 is used to connect the support member, the second flexible layer 300 may be provided with vent holes 310, which are located near the edge of the second flexible layer 300. The vent holes 310 provide an air discharge channel for the second flexible layer 300 during the bonding process, avoid air bubble residue, ensure effective adhesion between the heat dissipation layer and the second flexible layer 300, and ensure heat dissipation efficiency.

[0050] like Figure 5 As shown, in some embodiments, since the central region of the flexible display panel is the core bending region of the vehicle-mounted roll-up display device, the graphene layer 210 can be configured as a first portion 211 and a second portion 212 spaced apart from each other. Specifically, the first flexible layer 100 includes a first side and a second side disposed opposite to each other, the first portion 211 of the graphene layer 210 is disposed near the first side, and the second portion 212 of the graphene layer 210 is disposed near the second side; the step adhesive layer 220 includes a main structure 221 and an annular structure 222, the main structure 221 includes a first notch 2211 and a second notch 2212, the first notch 2211 is disposed corresponding to the first portion 211 and is used to accommodate the first portion 211, and the second notch 2212 is disposed corresponding to the second portion 212 and is used to accommodate the second portion 212; the annular structure 222 wraps around the circumferential outer side of the main structure 221, the first portion 211 and the second portion 212.

[0051] In the above structure, by dividing the graphene layer 210 into a first part 211 and a second part 212 near the two sides and avoiding the central bending region, and with the step adhesive layer 220 having notched grooves and annular structure 222, the highly thermally conductive but brittle graphene material is transferred from the high-stress, high-deformation-requirement central bending region to the low-stress, high-heat-flux-density edge region. The step adhesive layer 220 fills the edge anchoring and surface flattening, thereby reducing the risk of graphene failure due to bending fatigue while ensuring heat dissipation efficiency. At the same time, it optimizes the flexibility of the overall stack and reduces material costs.

[0052] Secondly, this application also provides a method for preparing a flexible display panel 20, comprising: S100: Fabrication of the first flexible layer 100; S200: A step adhesive layer 220 is laminated onto the first flexible layer 100; S300: A graphene layer 210 is composited on the first flexible layer 100, wherein the step adhesive layer 220 and the graphene layer 210 have the same thickness to form a heat dissipation layer 200. S400 has a second flexible layer 300 laminated on the side of the heat dissipation layer 200 opposite to the first flexible layer 100.

[0053] In the above steps, the first flexible layer 100 may include a first pressure-sensitive adhesive layer 110, a polyester film layer 120, and a second pressure-sensitive adhesive layer 130 connected in sequence, wherein the second pressure-sensitive adhesive layer 130 is used to connect with the heat dissipation layer 200. The thickness of the first pressure-sensitive adhesive layer 110 is between 10 μm and 20 μm; the thickness of the polyester film layer 120 is between 10 μm and 20 μm; and the thickness of the second pressure-sensitive adhesive layer 130 is between 10 μm and 20 μm.

[0054] In steps S200 and S300, by first setting the step adhesive layer 220 and then embedding graphene of equal thickness, the precise planarization of the heat dissipation layer 200 and the accurate positioning of the graphene layer 210 are achieved; providing a smooth composite surface for the subsequent setting of the second flexible layer 300.

[0055] In some embodiments, prior to step S400, the method for manufacturing the flexible display panel 20 further includes: setting an exhaust hole 310 on the second flexible layer 300 according to the curling position of the flexible display panel 20. Specifically, the exhaust hole 310 can be positioned to avoid the core curling area of ​​the flexible display panel 20; for example, the exhaust hole 310 can be positioned close to the edge of the second flexible layer 300. The second flexible layer 300 can gradually adhere to the heat dissipation layer 200 along the end away from the exhaust hole 310, and air between the heat dissipation layer 200 and the second flexible layer 300 can be discharged through the exhaust hole 310.

[0056] Thirdly, such as Figure 7 As shown, this application also provides a flexible display panel. The flexible display panel 20 includes a flexible display module 400 adhesive layer 10, through which the flexible display module 400 is bonded to the support member.

[0057] The adhesive layer 10 of this application adopts a sandwich-like structure and is used to attach the flexible display module 400 to the support. The heat dissipation layer 200 includes a graphene layer 210 and a step adhesive layer 220. The graphene layer 210 can rapidly diffuse localized hotspots of heat generated by the flexible display module 400 laterally, avoiding localized high temperatures and improving display uniformity and lifespan. The step adhesive layer 220 can anchor the edges of the graphene layer 210, reducing the risk of peeling and warping of the graphene layer 210, allowing the overall structure of the flexible display panel 20 to withstand the mechanical stress of rolling. Simultaneously, the graphene layer 210 can eliminate thickness steps created by the graphene layer, preventing the formation of bubbles. Furthermore, the heat dissipation layer 200 is integrated inside the flexible display panel 20 without adding extra thickness, meeting the requirements for thinner and lighter automotive displays. The design of the flexible display panel 20 enables the vehicle-mounted roll-up OLED display device to effectively solve the problem of local hot spots caused by the high thermal resistance of the Pattern support component while meeting the mechanical reliability requirements of repeated roll-up, thus achieving both good heat dissipation and mechanical reliability.

[0058] Fourthly, this application provides a display device, including the flexible display panel 20 of any of the above-mentioned features and a circuit board structure. Since the flexible display panel 20 of this application has advantages such as good heat dissipation and long service life, the display device having it also possesses these advantages.

[0059] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of this application. Therefore, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. An adhesive layer for a flexible display panel, characterized in that, include: A first flexible layer, a heat dissipation layer, and a second flexible layer are sequentially arranged; The heat dissipation layer includes a graphene layer and a step adhesive layer. The first flexible layer has a first surface connected to the heat dissipation layer, and the graphene layer has a second surface connected to the first flexible layer. The area of ​​the second surface is smaller than the area of ​​the first surface. The step adhesive layer is distributed on the outer periphery of the graphene layer so that the sum of the projected area of ​​the step adhesive layer on the first surface and the area of ​​the second surface is equal to the area of ​​the first surface.

2. The adhesive layer of the flexible display panel according to claim 1, characterized in that, The second flexible layer is used to connect the support components; The first flexible layer includes a first pressure-sensitive adhesive layer, a polyester film layer and a second pressure-sensitive adhesive layer arranged sequentially, wherein the second pressure-sensitive adhesive layer is connected to the heat dissipation layer.

3. The adhesive layer of the flexible display panel according to claim 2, characterized in that, The thickness of the first pressure-sensitive adhesive layer is between 10μm and 20μm; The thickness of the polyester film layer is between 10 μm and 20 μm; The thickness of the second pressure-sensitive adhesive layer is between 10μm and 20μm.

4. The adhesive layer of the flexible display panel according to claim 1, characterized in that, The modulus of the first flexible layer is less than 1 MPa; And / or, The modulus of the second flexible layer is less than 1 MPa.

5. The adhesive layer of the flexible display panel according to claim 1, characterized in that, The thickness of the graphene layer is between 30 μm and 150 μm.

6. The adhesive layer of the flexible display panel according to claim 1, characterized in that, The second flexible layer is used to connect the support member, and the second flexible layer is provided with vent holes, which are located near the edge of the second flexible layer.

7. The adhesive layer of the flexible display panel according to any one of claims 1 to 6, characterized in that, The center point of the graphene layer coincides with the center point of the first flexible layer, and the step adhesive layer has a ring structure, which wraps around the circumferential outer side of the graphene layer.

8. The adhesive layer of the flexible display panel according to any one of claims 1 to 6, characterized in that, The graphene layer includes a first portion and a second portion spaced apart. The first flexible layer includes a first side and a second side disposed opposite to each other, with the first portion disposed close to the first side and the second portion disposed close to the second side; The step adhesive layer includes a main structure and an annular structure. The main structure includes a first notch and a second notch. The first notch is corresponding to the first part and is used to accommodate the first part. The second notch is corresponding to the second part and is used to accommodate the second part. The annular structure wraps around the circumferential outer side of the main structure, the first part, and the second part.

9. A method for preparing an adhesive layer for a flexible display panel, characterized in that, include: Prepare the first flexible layer; A step adhesive layer is laminated onto the first flexible layer; A graphene layer is composited on the first flexible layer, wherein the step adhesive layer and the graphene layer have the same thickness to form a heat dissipation layer; A second flexible layer is laminated on the side of the heat dissipation layer opposite to the first flexible layer.

10. The method for preparing the adhesive layer of the flexible display panel according to claim 9, characterized in that, Prior to the step of laminating the second flexible layer onto the side of the heat dissipation layer opposite to the first flexible layer, the method further includes: Vent holes are provided on the second flexible layer according to the curling position of the flexible display panel.

11. A flexible display panel, characterized in that, include: Flexible display module; An adhesive layer, wherein the adhesive layer is any one of claims 1 to 8, wherein the flexible display module is bonded to the support member through the adhesive layer.

12. A display device, characterized in that, Includes the flexible display panel as described in claim 11.

Images