Display module and display device
Patent Information
- Application Number
- CN202510541416.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-27
- Publication Date
- 2026-10-27
Smart Images
Figure CN122991020A_ABST
Abstract
Description
Technical Field
[0001] This invention generally relates to the field of display technology, and more specifically to a display module and a display device. Background Technology
[0002] Currently, AMOLED (Active Matrix Organic Light Emitting Diode) display technology is becoming increasingly mature. With the growing demand for foldable screen phones, foldable screens are being made as thin and light as possible. However, the thin and light design results in a compact internal structure of the foldable screen, which in turn leads to more and more heat generation. Solving the problem of uniform heat dissipation across the entire foldable screen is of great significance to the development of foldable screen display devices. Summary of the Invention
[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a display module and display device that can uniformly conduct heat from the display panel by setting a heat transfer layer between the display panel and the support layer, so that the display panel can dissipate heat evenly, and the heat transfer layer structure will not peel off during the bending process of the display panel, thereby reliably improving the display effect of the display module and helping to improve the yield rate of the display panel and the product competitiveness.
[0004] In a first aspect, the present invention provides a display module, comprising:
[0005] Display panel;
[0006] The heat transfer layer is located on the backlight side of the display panel. The heat transfer layer includes a heat-conducting layer and a protective layer stacked along a direction perpendicular to the display panel. The protective layers are located on opposite sides of the heat-conducting layer. The modulus of the protective layer is greater than that of the heat-conducting layer.
[0007] The support layer is located on the side of the heat transfer layer that faces away from the display panel.
[0008] As an alternative, the heat transfer layer can be projected onto the display panel to completely cover it.
[0009] As an alternative, in a direction parallel to the display panel, the edge of the heat-conducting layer is recessed relative to the edge of the protective layer, and a gap is formed between the edge of the heat-conducting layer and the edge of the protective layer.
[0010] As an optional solution, the distance between the edge of the thermal conductive layer and the edge of the protective layer is 0.7mm-1.5mm in the direction parallel to the display panel.
[0011] As an optional solution, the gap is filled with edge-sealing adhesive.
[0012] As an optional solution, the thickness of the thermal conductive layer is 30μm-60μm.
[0013] As an optional solution, the thickness of the protective layer is less than the thickness of the heat-conducting layer;
[0014] As an optional solution, the thickness of the protective layer is 8μm-25μm.
[0015] As an optional solution, the thermally conductive layer may include graphite or graphene; the protective layer may include organic polymer or metallic materials.
[0016] As an optional solution, the protective layers on both sides of the thermally conductive layer are made of the same material, namely PET or PI.
[0017] As an optional solution, a first optical pressure-sensitive adhesive layer is provided on the side of the heat transfer layer away from the display panel, and a second optical pressure-sensitive adhesive layer is provided on the side of the heat transfer layer close to the display panel. The heat transfer layer is bonded and fixed to the support layer through the first optical pressure-sensitive adhesive layer, and the heat transfer layer is bonded and fixed to the display panel through the second optical pressure-sensitive adhesive layer.
[0018] In a second aspect, the present invention provides a display device, including the display module of the first aspect.
[0019] The display module of the present invention incorporates a heat transfer layer on the backlight side of the display panel, positioned between the display panel and the support layer. This allows the heat transfer layer to be built into the display module. Because the heat transfer layer is close to the display panel, it can reliably and uniformly conduct heat from the display panel, ensuring even heat dissipation and avoiding problems such as TFT (thin-film transistor) electrical offset and color shift caused by uneven heat dissipation in folding displays. Furthermore, since protective layers are provided on both sides of the heat transfer layer, and the modulus of the protective layers is greater than that of the heat transfer layers, the heat transfer layers will not peel off during the bending process of the display panel. This ensures the stability of the entire heat transfer layer structure, reliably improving the display effect and lifespan of the display module, thereby enhancing the yield rate and product competitiveness of the display panel. Attached Figure Description
[0020] Other features, objectives, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:
[0021] Figure 1 This is a schematic diagram of the structure of an existing foldable screen;
[0022] Figure 2 A schematic diagram of heat distribution in an existing foldable screen;
[0023] Figure 3 This is a schematic diagram of an existing external heat dissipation structure for foldable screens.
[0024] Figure 4 This is a schematic diagram of the cross-sectional structure of an existing foldable screen;
[0025] Figure 5 This is a schematic diagram of graphite bending and layering.
[0026] Figure 6 This is a schematic diagram of the display module structure of this application;
[0027] Figure 7 This is a schematic diagram of the structure of the heat transfer layer in this application;
[0028] Figure 8 SEM images of graphite;
[0029] Figure 9 SEM images of graphite;
[0030] Figure 10 Photographs of surface printing on graphite without a PET layer;
[0031] Figure 11 Surface printing photographs showing a PET layer applied to a graphite surface;
[0032] Figure 12 A schematic diagram of the structure of the release film removed when no protective layer is applied to the surface of the thermally conductive layer;
[0033] Figure 13 A photograph showing the delamination of the thermal conductive layer after removing the release film without a protective layer on its surface.
[0034] Figure 14 A schematic diagram of the structure of the release film for removing the protective layer on the surface of the thermally conductive layer.
[0035] In the picture,
[0036] 100. Display module;
[0037] 1. Heat dissipation material; 2. Heat transfer barrier zone; 3. FEP (Fuel Precipitator);
[0038] 10. Display panel; 11. Back film;
[0039] 20. Heat transfer layer; 21. Heat conduction layer; 22. Protective layer;
[0040] 30. Support layer;
[0041] 40. Edge sealing adhesive;
[0042] 50. First optical pressure-sensitive adhesive layer; 60. Second optical pressure-sensitive adhesive layer; 70. Cover plate;
[0043] 80. First release film; 81. Second release film. Detailed Implementation
[0044] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.
[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0046] As AMOLED technology matures, more and more people are choosing foldable phones. To enhance user comfort, foldable phones are also evolving towards thinner and lighter designs. The increasing thinness and lightness of foldable phones necessitates minimizing the thickness and weight of the display module materials, and requiring increasingly compact integration within the entire device. However, due to the increasing adoption of 5G signals and high refresh rates, the compact display design leads to higher heat generation. For the same volume, a foldable screen has three times the display area of a conventional phone, making heat dissipation significantly more challenging. Figure 1-3 As shown, conventional foldable phones use graphite sheets or VC heat sinks on the back of the display screen for heat dissipation. These heat dissipation materials help distribute heat evenly across the entire screen and dissipate it quickly, preventing uneven heating. However, conventional VC heat sinks cannot be repeatedly bent and cannot be used in bending areas. Furthermore, conventional graphite has a modulus of 30 MPa, and its sheet-like structure is prone to delamination during use. Figure 5 Due to the performance requirements of foldable phones, heat dissipation material 1 can only be added to the left and right sides of the foldable screen (e.g., Figure 4 Currently, the folding section lacks bend-resistant heat dissipation material. Current foldable phones typically use an external method, attaching a layer of graphene to the BKT (support layer) on the back of the display module, away from the display panel. Graphene passes through the hinge in the middle area; this graphene is very narrow and not adhered to the display module (e.g., ...). Figure 3 At this point, some of the heat is conducted through the left and right screens. Because the heat transfer in the middle is limited, the left and right screens of the foldable phone cannot be evenly distributed. With prolonged use, the foldable display will experience TFT electrical shift due to uneven heating, leading to problems such as color shift and mura.
[0047] Based on the above problems, the embodiments of this application provide a heat transfer layer 20 built into the display module 100, so that the heat is evenly distributed on the entire surface of the display panel 10. While achieving uniform heat dissipation, the structure of the heat transfer layer 20 remains stable during the bending process of the display panel 10, thereby ensuring uniform heat dissipation of the display panel 10 and improving the display effect of the display panel 10.
[0048] Specifically, embodiments of this application provide a display module 100, such as... Figure 6 As shown, it includes:
[0049] Display panel 10;
[0050] The heat transfer layer 20 is located on the backlight side of the display panel 10. The heat transfer layer 20 includes a heat-conducting layer 21 and a protective layer 22 stacked along a direction perpendicular to the display panel 10. The protective layer 22 is located on opposite sides of the heat-conducting layer 21. The modulus of the protective layer 22 is greater than that of the heat-conducting layer 21.
[0051] Support layer 30 is located on the side of heat transfer layer 20 away from display panel 10.
[0052] It should be noted that the display panel 10 in the embodiments of this application can be a curved display panel 10, or it can be a flat display panel 10. A curved display panel 10 includes a flat center and curved edges; or a foldable display panel 10, where the two sides are flat and the center is folded. The display panel 10 includes a display area and a non-display area (peripheral area) located around the display area. The display area is used for display, and the non-display area includes bonding pad areas and areas for mounting other structures. The non-display area may include one bonding pad area. Alternatively, depending on actual process requirements, the non-display area may have two or more bonding pad areas.
[0053] Understandably, the heat transfer layer 20 is mainly used to uniformly conduct heat from the display panel 10, enabling rapid and uniform heat dissipation across the entire surface of the display panel 10 (including flat and bent areas). The heat transfer layer 20 includes a heat-conducting layer 21 and a protective layer 22. The protective layer 22 is mainly used to protect the heat-conducting layer 21, preventing it from peeling off during the bending or installation process of the display panel 10. Simultaneously, the protective layer 22 adheres to the surface of the heat-conducting layer 21, blocking the microstructure of the heat-conducting layer 21's surface. Furthermore, the protective layer 22 can also mitigate the problem of orange peel-like defects on the display screen surface caused by the direct adhesion of the heat-conducting layer 21 to the display panel 10 due to surface roughness.
[0054] The thermally conductive layer 21 can be, but is not limited to, any material with good thermal conductivity and elongation, such as, but not limited to, graphite or graphene. Similarly, the protective layer 22 can also be any material with good thermal conductivity and elongation, provided that the modulus of the protective layer 22 is greater than that of the thermally conductive layer 21. This ensures that during the bending process of the display panel 10, the protective layer 22 protects the graphite while reducing bending stress and preventing breakage. In some embodiments, the protective layer 22 can be an organic polymer material, or even a metallic material. Protective layers 22 are provided on opposite sides of the thermally conductive layer 21 in a direction perpendicular to the display panel 10. The protective layer 22 and the thermally conductive layer 21 can be bonded together using any adhesive, such as, but not limited to, pressure-sensitive adhesive (PSA).
[0055] It is also understandable that, in order to avoid orange peel texture on the display screen, the surface of the protective layer 22 near the display panel 10 should be as smooth as possible.
[0056] In actual processing, the heat transfer layer 20 can also be obtained by adding thermally conductive layer 21 material and protective layer 22 material to a conventional FEP (Flexible EMBO PSA, mesh adhesive) layer; among which, the FEP layer is usually used to connect the display panel 10 (Panel) and the substrate (SUS), mainly to protect the display panel 10 during bending.
[0057] The support layer 30 is mainly used to support and protect the display panel 10. The support layer 30 can be, but is not limited to, SCF (super-clean film) or a combination of SCF, adhesive layer and metal layer, etc., and can be used for back cushioning support and heat dissipation of the display panel 10.
[0058] The display module of this application solves the problem of poor display caused by uneven heat dissipation in existing foldable screens. The display module of this application, by providing a heat transfer layer 20 on the backlight side of the display panel 10, and with the heat transfer layer 20 located between the display panel 10 and the support layer 30, effectively embeds the heat transfer layer 20 within the display module. Because the heat transfer layer 20 is close to the display panel 10, it can reliably and evenly conduct heat from the display panel 10, ensuring uniform heat dissipation and avoiding problems such as TFT (thin-film transistor) electrical offset and color shift caused by uneven heat dissipation in foldable displays. Furthermore, since protective layers 22 are provided on both sides of the heat-conducting layer 21, and the modulus of the protective layer 22 is greater than that of the heat-conducting layer 21, bending stress is reduced during the bending process of the display panel 10, preventing the heat-conducting layer 21 from peeling off. This makes the entire heat transfer layer 20 structure stable, reliably improving the display effect and lifespan of the display module, thereby increasing the yield rate and product competitiveness of the display panel 10.
[0059] In some embodiments, a back film 11 is further provided on the backlight side of the display panel 10, and a heat transfer layer 20 is located on the side of the back film 11 away from the display panel 10.
[0060] The back film 11 can be a U-Film film, which is attached to the backlight side of the display panel 10 and is mainly used to protect and support the display panel 10. The back film 11 may include an acrylic film (Acryl film) and a polyethylene terephthalate film (PET film) stacked together.
[0061] Due to the current processing technology of the display panel 10, the back film 11 is already covered on the backlight side of the display panel 10 after the display panel 10 is processed. Therefore, in this embodiment, the heat transfer layer 20 is disposed on the side of the back film 11 away from the display panel 10, which helps to simplify the processing technology while ensuring uniform heat dissipation of the display panel 10.
[0062] In some other embodiments, the heat transfer layer 20 can also be displayed between the panel 10 and the back film 11, which is beneficial to improve heat dissipation efficiency, but requires high process requirements.
[0063] As an achievable method, the orthographic projection of the heat transfer layer 20 onto the display panel 10 completely covers the display panel 10.
[0064] It is understandable that the orthographic projection of the heat transfer layer 20 on the display panel 10 completely covers the display panel 10. That is, the orthographic projection of the heat transfer layer 20 on the display panel 10 covers both the display area and the non-display area of the display panel 10. This is beneficial for the uniform transfer of heat across the entire display panel 10, thereby reliably avoiding the problem of severe overheating of the entire module, and at the same time, it helps to ensure that the display module has a good display effect.
[0065] In some embodiments, in a direction parallel to the display panel 10, the edge of the heat-conducting layer 21 is recessed relative to the edge of the protective layer 22, and a gap is formed between the edge of the heat-conducting layer 21 and the edge of the protective layer 22.
[0066] Specifically, such as Figure 7 As shown, in the direction parallel to the display panel 10 (X direction), the edge B1 of the heat-conducting layer 21 is recessed relative to the edge B2 of the protective layer 22. This ensures that the heat-conducting layer 21 is always protected by the protective layer 22, preventing the edge of the heat-conducting layer 21 from being flush with the edge of the protective layer 22, which would expose the protective layer 22 to the outside and cause the heat-conducting layer 21 to peel off or affect the display effect of the display panel 10.
[0067] In this embodiment, the way the heat-conducting layer 21 is set helps to ensure the structural stability of the heat-conducting layer 21, thereby ensuring reliable heat conduction of the display panel 10, so that the display panel 10 dissipates heat evenly and ensures that the display panel 10 has a good display effect.
[0068] In some embodiments, such as Figure 7 As shown, in a direction parallel to the display panel 10 (e.g.) Figure 7 In the X direction), the distance between the edge B1 of the heat-conducting layer 21 and the edge B2 of the protective layer 22 is 0.7mm-1.5mm.
[0069] Specifically, the distance between the edge of the heat-conducting layer 21 and the edge of the protective layer 22 can be, but is not limited to, 0.7mm, 0.9mm, 1.1mm, 1.3mm, or 1.5mm. When the distance between the edge of the heat-conducting layer 21 and the edge of the protective layer 22 is less than 0.7mm, it may result in the inability to effectively protect the edge of the heat-conducting layer 21, causing the heat-conducting layer 21 to peel off. When the distance between the edge of the heat-conducting layer 21 and the edge of the protective layer 22 is greater than 1.5mm, the area covered by the orthographic projection of the heat-conducting layer 21 on the display panel 10 is small, resulting in poor heat dissipation effect of the heat-conducting layer 21 on the display panel 10.
[0070] In this embodiment, the distance between the edge of the heat-conducting layer 21 and the edge of the protective layer 22 is beneficial to protect the edge of the heat-conducting layer 21, so that the structure of the heat-conducting layer 21 is stable and has sufficient heat dissipation effect, ensuring uniform heat dissipation of the display panel 10 and good display effect.
[0071] As an option, the gap is filled with edge-sealing adhesive 40.
[0072] Among them, the edge sealing adhesive 40 can be any kind of sealant, such as, but not limited to, PSA.
[0073] In this embodiment, the gaps between the edge of the heat-conducting layer 21 and the edge of the protective layer 22 are filled with sealant, which helps to further reliably protect the edge of the heat-conducting layer 21 and prevent it from falling off or peeling off during the bending of the display panel 10.
[0074] In some embodiments, the thickness of the thermally conductive layer 21 is 30μm-60μm.
[0075] Specifically, the thickness of the heat-conducting layer 21 can be, but is not limited to, 30μm, 40μm, 50μm, or 60μm. When the thickness of the heat-conducting layer 21 is less than 30μm, the heat-conducting layer 21 does not have sufficient heat dissipation effect; when the thickness of the heat-conducting layer 21 is greater than 60μm, the heat-conducting layer 21 is too thick, affecting the bending performance of the display panel 10 and the thickness of the entire display module.
[0076] The thickness of the heat-conducting layer 21 in this embodiment is conducive to ensuring that the heat-conducting layer 21 has sufficient heat dissipation effect, while not causing the thickness of the entire display module to be too large.
[0077] As a possible approach, the thickness of the protective layer 22 is less than the thickness of the thermally conductive layer 21.
[0078] In this embodiment, the thickness of the protective layer 22 is beneficial to reliably protect the heat-conducting layer 21 while avoiding the protective layer 22 being too thick, which would affect the heat dissipation effect of the heat-conducting layer 21 and the bending performance of the display panel 10.
[0079] In some embodiments, the thickness of the protective layer 22 is 8μm-25μm.
[0080] Specifically, the thickness of the protective layer 22 can be, but is not limited to, 8μm, 12μm, 15μm, 20μm, or 25μm. When the thickness of the protective layer 22 is less than 8μm, it may cause the protective layer 22 to break during the bending process of the display panel 10, thus failing to reliably protect the heat-conducting layer 21 and causing the heat-conducting layer 21 to peel off. When the thickness of the protective layer 22 is greater than 25μm, the thickness of the protective layer 22 is too large, which affects the bending performance of the display panel 10 and also causes the thickness of the entire display module to be too large.
[0081] In a preferred embodiment, the thermally conductive layer 21 comprises graphite or graphene; the protective layer 22 comprises an organic polymer or a metallic material.
[0082] Graphite and graphene have good thermal conductivity and ductility. Organic polymers and metal materials have good thermal conductivity, high modulus, and high tensile recovery rate. This can reliably protect graphite or graphene and prevent graphite or graphene from peeling, breaking during bending, or graphite delamination caused by the peeling force of the film during the assembly of the heat transfer layer 20 and the display panel 10.
[0083] Among them, organic polymers can be, but are not limited to, PET or PI; metallic materials can be, but are not limited to, copper.
[0084] In a preferred embodiment, the protective layers 22 located on both sides of the thermally conductive layer 21 are made of the same material, namely PET or PI.
[0085] In this embodiment, the protective layers 22 on both sides of the heat-conducting layer 21 are made of the same material, which makes them easy to process.
[0086] As an implementation method, a first optical pressure-sensitive adhesive layer 50 is provided on the side of the heat transfer layer 20 away from the display panel 10, and a second optical pressure-sensitive adhesive layer 60 is provided on the side of the heat transfer layer 20 close to the display panel 10. The heat transfer layer 20 is bonded and fixed to the support layer 30 through the first optical pressure-sensitive adhesive layer 50, and the heat transfer layer 20 is bonded and fixed to the display panel 10 through the second optical pressure-sensitive adhesive layer 60.
[0087] This embodiment helps to fix the heat transfer layer 20, the display panel 10, and the support layer 30, thereby ensuring the structural stability of the heat transfer layer 20 and enabling the display panel 10 to dissipate heat evenly.
[0088] In some embodiments, the display panel 10 includes a substrate, which may be, but is not limited to, a silicon substrate. The silicon substrate may include a silicon substrate and a driving layer, a display layer, a polarizer, a cover plate 70, etc., stacked on the silicon substrate in a direction away from the silicon substrate.
[0089] The driving layer may include multiple pixel driving circuits arranged in an array. Each pixel driving circuit may include multiple transistors and capacitors, among other electronic components. For example, each pixel driving circuit may include three transistors and one capacitor, forming a 3T1C (i.e., one driving transistor, two switching transistors, and one capacitor). It may also include more than three transistors and at least one capacitor, such as 4T1C (i.e., one driving transistor, three switching transistors, and one capacitor), 5T1C (i.e., one driving transistor, four switching transistors, and one capacitor), or 7T1C (i.e., one driving transistor, six switching transistors, and one capacitor), etc. The transistors may be thin-film transistors (TFTs).
[0090] It is understood that a thin-film transistor (TFT) may include a control electrode, a first electrode, and a second electrode. The control electrode is the gate of the TFT, the first electrode is one of the source and drain of the TFT, and the second electrode is the other of the source and drain of the TFT.
[0091] In some embodiments, the driving layer may include an active layer, a first gate metal layer (Gate1), a second gate metal layer (Gate2), a first metal trace layer (SD1), and a second metal trace layer (SD2). These layers are configured to form thin-film transistors, capacitors, and multiple signal lines for pixel driving in a pixel driving circuit. For example, the multiple signal lines may include power signal lines, data signal lines, reset signal lines, scan signal lines, enable signal lines, and initialization signal lines, etc. The driving layer may also include insulating layers that space these layers apart.
[0092] The display layer may include a light-emitting device layer and an encapsulation layer. The light-emitting device layer is stacked on the side of the driving layer away from the substrate. The light-emitting device layer may include a pixel definition layer and multiple light-emitting devices. The pixel definition layer has multiple pixel openings, and each pixel opening defines the position of a light-emitting device to form a sub-pixel. For example, the light-emitting device may be an OLED light-emitting device or a QLED light-emitting device. Taking an OLED light-emitting device as an example, along the direction away from the substrate, the light-emitting device may include a first electrode, a light-emitting layer, and a second electrode stacked sequentially. Of course, the light-emitting device may also include at least one of a hole injection layer, a hole transport layer, and an electron blocking layer disposed between the first electrode and the light-emitting layer, and at least one of an electron injection layer, an electron transport layer, and a hole blocking layer disposed between the second electrode and the light-emitting layer; in some embodiments, the first electrode may be an anode layer, and the second electrode may be a cathode layer. The anode layer may be a composite structure composed of a transparent conductive oxide film / metal film / transparent conductive oxide film stacked sequentially. The transparent conductive oxide film is made of materials such as ITO (Indium Tin Oxide) and IZO (Indium Zinc Oxide), and the metal film is made of materials such as gold (Au), silver (Ag), nickel (Ni), and platinum (Pt). For example, the anode layer can also be a single-layer structure, and the material of the single-layer structure can be any of ITO, IZO, Au, Ag, Ni, and Pt. Each pixel opening exposes a portion of the anode layer of the corresponding light-emitting device, and at least a portion of the light-emitting layer is located within the corresponding pixel opening, forming an electrical connection with the corresponding anode layer. For example, the cathode layers of each light-emitting device can be electrically connected to each other, forming a single structure. For example, the cathode layer material can be any of aluminum (Al), silver (Ag), and magnesium (Mg), or any of magnesium-silver alloys and aluminum-lithium alloys.
[0093] An encapsulation layer is disposed on the side of the light-emitting device layer away from the substrate to protect the light-emitting device. The encapsulation layer may include a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer. For example, the first and second inorganic encapsulation layers may be made of inorganic materials such as nitrides, oxides, oxynitrides, nitrates, carbides, or any combination thereof, and the fabrication process may employ chemical vapor deposition (CVD), such as plasma-enhanced chemical vapor deposition (PECVD). For example, the organic insulating layer may be made of materials such as acrylic fiber, hexamethyldisiloxane, polyacrylates, polycarbonate, or polystyrene, and the fabrication process may employ inkjet printing (IJP).
[0094] In some embodiments, the display module further includes a heat dissipation film disposed on the backlight side of the display panel 10 along a direction away from the display panel 10.
[0095] The heat dissipation film is located on the side of the back film 11 away from the display panel 10. The heat dissipation film can be a superclean foam (SCF) composite film; of course, the heat dissipation film can also adopt a multi-layer stacked structure, wherein the heat dissipation film includes a metal layer. The metal has heat dissipation and electrical conductivity properties. The metal layer can generally be made of copper (Cu) or aluminum (Al); the heat dissipation film can also include an adhesive layer and a functional layer located between the adhesive layer and the metal layer. The adhesive layer is used to bond the heat dissipation film to the backlight side of the display panel 10. The adhesive layer can be made of embossing adhesive (EMBO) or other adhesive materials. Embossing adhesive helps to reduce air bubbles generated when bonding with the display panel 10, thereby enhancing the connection strength between the display panel 10 and the heat dissipation film. In practical use, a protective film layer is provided on the adhesive layer of the heat dissipation film on the side opposite to the metal layer to protect the film layer. When using the heat dissipation film, this protective film layer needs to be peeled off first. The functional layer has stress buffering properties, which can buffer the stress and impact applied to the display panel 10 from the outside. Specifically, the functional layer may include a foam layer, which is disposed on the side of the adhesive layer close to the metal layer. The material of the foam layer can be polyurethane (PU) or other materials. In some other embodiments, the functional layer may also include a support layer, which is disposed on the side of the foam layer close to the metal layer, and plays a supporting and impact-resistant role. The support layer can be black to enhance the all-black effect of the product. The support layer can be black PI (Polyimide).
[0096] In summary, the display module of this application, by providing a heat transfer layer 20 on the backlight side of the display panel 10 and placing the heat transfer layer 20 between the display panel 10 and the support layer 30, allows the heat transfer layer 20 to be built into the display module. Since the heat transfer layer 20 is close to the display panel 10, it can reliably and uniformly conduct the heat of the display panel 10, enabling the display panel 10 to dissipate heat evenly and avoiding problems such as TFT (thin film transistor) electrical offset and color shift caused by uneven heat dissipation in folding displays. Furthermore, since protective layers 22 are provided on both sides of the heat-conducting layer 21, and the modulus of the protective layer 22 is greater than that of the heat-conducting layer 21, the heat-conducting layer 21 will not peel off during the bending process of the display panel 10, thereby making the entire heat transfer layer 20 structure stable and reliably improving the display effect and service life of the display module.
[0097] Furthermore, the edge of the heat-conducting layer 21 is recessed relative to the edge of the protective layer 22, and the edge sealing adhesive 40 is filled between the edge of the heat-conducting layer 21 and the edge of the protective layer 22, so as to completely wrap the heat-conducting layer 21, protect the heat-conducting layer 21 from peeling or falling off, thereby making the structure of the heat transfer layer 20 stable and able to reliably dissipate heat evenly to the display panel, which in turn helps to improve the yield rate and product competitiveness of the display panel 10.
[0098] The display module of this application will be described below through specific embodiments.
[0099] Example 1
[0100] The display module includes a display panel 10. A back film 11, a heat transfer layer 20 and a support layer 30 are stacked on the back side of the display panel 10 along the direction away from the display panel 10. The heat transfer layer 20 includes a first PET layer, a graphite layer and a second PET layer stacked along the direction away from the display panel 10.
[0101] like Figure 8 and 9 As shown, graphite has a sheet-like microstructure and a high surface roughness after being rolled into rolls. If graphite is directly bonded to the display panel 10, an orange peel effect will be directly visible on the screen surface (e.g., Figure 10 As shown), adding a PET layer to the graphite surface can effectively block the microstructure of the graphite surface. After the PET is bonded to the display panel 10, the orange peel effect is significantly reduced to an invisible level (e.g., Figure 11 (as shown);
[0102] In actual processing, a first optical pressure-sensitive adhesive layer 50 and a second optical pressure-sensitive adhesive layer 60 are provided on the two opposing surfaces of the heat transfer layer 20. A first release film 80 is provided on one side of the first optical pressure-sensitive adhesive layer 50, and a second release film 81 is provided on one side of the second optical pressure-sensitive adhesive layer 60. When removing the first release film 80 and the second release film 81, if the PET layer is not provided, the peeling force will be directly transmitted to the graphite through the first optical pressure-sensitive adhesive layer 50, resulting in graphite delamination (e.g., ...). Figure 12 and 13 (As shown). A PET layer is disposed on the graphite layer, such as... Figure 14 As shown, since the modulus of PET (approximately 3 GPa) is much larger than that of PSA (30 MPa), and PET itself has better stiffness, PET can absorb the peeling force when the film is peeled off, thus protecting the graphite and preventing graphite delamination.
[0103] Example 2
[0104] Table 1 shows a comparison of the simulated stress values for the graphite layer and the heat transfer layer 20. Graphite 1, a standalone graphite layer, is bonded to both the display panel 10 and the support layer 30 via PSA bonding. The stress on this graphite layer is 34.4 MPa, exceeding the maximum stress. Graphite 2, with a PET layer on one side, is bonded to both the display panel 10 and the support layer 30 via PSA bonding. The stress on this graphite layer also exceeds its maximum stress. In the heat transfer layer 20, PET layers are applied to both sides of the graphite layer, which are then bonded to both the display panel 10 and the support layer 30 via PSA bonding. Because the modulus of PET is greater than that of graphite, the PET layer can absorb more stress during bending stress analysis, thus reducing the stress on the graphite layer to 23.7 MPa, reaching a safe value. The thickness of the graphite layer is 32 μm, the PSA layer is 15 μm, and the PET layer is 10 μm.
[0105] Table 1 Comparison of stress simulation values for adding graphite and heat transfer layers in FEP
[0106]
[0107] Secondly, the present invention provides a display device including the display module of the first aspect. It is understood that this display device possesses all the features and advantages of the aforementioned display module, which will not be repeated here. In summary, this display device has high quality and yield, and high display resolution.
[0108] A display device is a product with image display capabilities. For example, a display device can be any of the following: monitor, television, billboard, digital photo frame, laser printer with display function, telephone, mobile phone, personal digital assistant (PDA), digital camera, portable camcorder, viewfinder, navigator, vehicle, large-area wall, home appliance, information query equipment (such as business query equipment for e-government, banks, hospitals, power companies, etc.), monitor, etc. A display device can also be a microdisplay or a product containing a microdisplay. Products containing microdisplays can be any of the following: smartwatch, smart bracelet, helmet display, stereoscopic display, and AR devices (such as AR glasses), VR devices (such as VR glasses), etc. For example, a microdisplay can be a display with a display size ranging from approximately 0.2 inches to approximately 2.5 inches, but is not limited to this. Understandably, a microdisplay can also be a display with a smaller display size, such as a display size less than or equal to 0.2 inches.
[0109] It should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., used above to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the panel or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the invention, unless otherwise stated, "a plurality of" means two or more.
[0110] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.
Claims
1. A display module, characterized in that, include: Display panel; A heat transfer layer is located on the backlight side of the display panel. The heat transfer layer includes a thermally conductive layer and a protective layer stacked along a direction perpendicular to the display panel. The protective layers are located on opposite sides of the thermally conductive layer. The modulus of the protective layer is greater than that of the thermally conductive layer. A support layer is located on the side of the heat transfer layer opposite to the display panel.
2. The display module according to claim 1, characterized in that, The orthographic projection of the heat transfer layer onto the display panel completely covers the display panel.
3. The display module according to claim 1, characterized in that, In a direction parallel to the display panel, the edge of the thermal conductive layer is recessed relative to the edge of the protective layer, and a gap is formed between the edge of the thermal conductive layer and the edge of the protective layer.
4. The display module according to claim 3, characterized in that, In a direction parallel to the display panel, the distance between the edge of the thermal conductive layer and the edge of the protective layer is 0.7mm-1.5mm.
5. The display module according to claim 3, characterized in that, The gap is filled with edge sealing adhesive.
6. The display module according to claim 1, characterized in that, The thickness of the thermally conductive layer is 30μm-60μm.
7. The display module according to claim 6, characterized in that, The thickness of the protective layer is less than the thickness of the thermally conductive layer; Preferably, the thickness of the protective layer is 8μm-25μm.
8. The display module according to claim 1, characterized in that, The thermally conductive layer comprises graphite or graphene; the protective layer comprises an organic polymer or a metallic material. Preferably, the protective layers located on both sides of the thermally conductive layer are made of the same material, and the material of the protective layer is PET or PI.
9. The display module according to claim 8, characterized in that, A first optical pressure-sensitive adhesive layer is provided on the side of the heat transfer layer away from the display panel, and a second optical pressure-sensitive adhesive layer is provided on the side of the heat transfer layer close to the display panel. The heat transfer layer is bonded and fixed to the support layer through the first optical pressure-sensitive adhesive layer, and the heat transfer layer is bonded and fixed to the display panel through the second optical pressure-sensitive adhesive layer.
10. A display device, characterized in that, Includes the display module as described in any one of claims 1-9.