Display module and electronic device

Abstract

The application provides a display module and an electronic device. The display module comprises a display panel, a flexible circuit board and a composite film layer. The display panel comprises a display area and a non-display area. The non-display area is provided with a binding portion. The flexible circuit board is connected to the binding portion. The composite film layer is arranged on the flexible circuit board away from the binding portion to cover at least part of the device thereon. The composite film layer comprises a metal film layer, a first conductive adhesive layer, a flexible conductive layer and a second conductive adhesive layer arranged in layers. The first conductive adhesive layer is provided with first conductive particles. The second conductive adhesive layer is provided with second conductive particles. The modulus of the first conductive adhesive layer is higher than that of the second conductive adhesive layer. The density of the first conductive particles in the first conductive adhesive layer is higher than that of the second conductive particles in the second conductive adhesive layer. In this way, the composite film layer has excellent shielding ground effect and greatly improves the vertical and overlapping conductive performance.

Description

Technical Field

[0001] This application relates to the field of display technology, and more specifically, to display module structure design technology in the field of display technology, particularly a display module and electronic device. Background Technology

[0002] With the continuous development of OLED (Organic Light-Emitting Diode) display technology, flexible OLED tablets, laptops, and automotive displays are widely used. The impact of electromagnetic interference on displays cannot be ignored. Electromagnetic interference can easily cause display distortion or increase power consumption. Because copper foil has good heat dissipation, shielding, and conductivity, it is currently widely used in modules. Adhesive tape with copper foil can shield crosstalk and achieve effective heat dissipation. At the same time, copper foil can also ground the exposed copper area on the FPC to other areas.

[0003] Because copper foil is relatively rigid, the adhesive layer of the copper foil tape needs to be thickened during use. However, thickening the adhesive layer leads to a decrease in conductivity, especially an increase in lap resistance. This is because a thicker adhesive layer increases the likelihood of uneven distribution of conductive particles within the layer, and also increases the distance between the copper foil and the substrate. Summary of the Invention

[0004] In view of this, the purpose of this disclosure is to propose a display module and electronic device, and to optimize the composite film layer of the display module to improve the shielding effect.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] A display module comprising:

[0007] The display module includes a display panel, a flexible circuit board, and a composite film layer.

[0008] The display panel includes a display area and a non-display area located at least on one side of the periphery of the display area.

[0009] The display area includes pixels arranged in an array, and each pixel is configured with a pixel driving circuit;

[0010] The non-display area is provided with a binding part;

[0011] The flexible circuit board is connected to the bonding part;

[0012] The composite film layer is disposed on the flexible circuit board away from the bonding portion to cover at least a portion of the devices thereon. The composite film layer includes a stacked metal film layer, a first conductive adhesive layer, a flexible conductive layer, and a second conductive adhesive layer.

[0013] The first conductive adhesive layer contains first conductive particles, and the second conductive adhesive layer contains second conductive particles.

[0014] Wherein, the modulus of the first conductive adhesive layer is higher than that of the second conductive adhesive layer, and the density of the first conductive particles in the first conductive adhesive layer is higher than that of the second conductive particles in the second conductive adhesive layer.

[0015] In one embodiment, the metal film layer is a copper foil layer, and the thickness of the copper foil layer is between 9-20 μm;

[0016] Preferably, the thickness of the copper foil layer is between 10-18 μm;

[0017] Preferably, the thickness of the copper foil layer is between 13-15 μm.

[0018] In one embodiment, the metal film layer is an aluminum foil layer, and the thickness of the aluminum foil layer is between 9-20 μm;

[0019] The metal film layer is a copper-aluminum alloy, and the thickness of the copper-aluminum alloy layer is between 9-20 μm.

[0020] In one embodiment, the flexible conductive layer comprises a conductive fiber cloth.

[0021] In one embodiment, the conductive fiber cloth includes one or a combination of nickel-plated conductive cloth, gold-plated conductive cloth, carbon-plated conductive cloth, or aluminum foil fiber composite cloth.

[0022] Preferably, the conductive fiber cloth is a gold-plated conductive cloth;

[0023] Preferably, the conductive fiber cloth is a nickel-plated conductive cloth.

[0024] In one embodiment, the thickness of the flexible conductive layer is between 10-15 μm;

[0025] Preferably, the thickness of the flexible conductive layer is between 11-14 μm;

[0026] Preferably, the thickness of the flexible conductive layer is between 12-13 μm.

[0027] In one embodiment, the thickness of the first conductive adhesive layer is between 5 and 10 μm;

[0028] Preferably, the thickness of the first conductive adhesive layer is between 6-9 μm;

[0029] Preferably, the thickness of the first conductive adhesive layer is between 7-8 μm.

[0030] In one embodiment, the thickness of the second conductive adhesive layer is between 5.5 and 15 μm;

[0031] Preferably, the thickness of the second conductive adhesive layer is between 8-13 μm;

[0032] Preferably, the thickness of the second conductive adhesive layer is between 10-12 μm.

[0033] The thickness of the first conductive adhesive layer is smaller than the thickness of the second conductive adhesive layer;

[0034] The surface roughness of the first surface of the second conductive adhesive layer is greater than 0.25 μm.

[0035] The interior of the flexible conductive layer provides a channel for current transmission;

[0036] In one embodiment, the first surface of the first conductive adhesive layer is bonded to the first surface of the metal film layer, and the second surface of the first conductive adhesive layer is bonded to the first surface of the flexible conductive layer;

[0037] The first surface of the second conductive adhesive layer is provided with a plurality of inward grooves, and the second surface of the flexible conductive layer is bonded to the first surface of the second conductive adhesive layer;

[0038] Preferably, the groove is shaped as a cube, a cone, or a hemispherical shape.

[0039] Preferably, the groove is shaped like a cone.

[0040] Based on the same inventive concept, this application proposes an electronic device that includes the aforementioned display module.

[0041] Compared with the prior art, the display module proposed in this application optimizes the structure of the composite film layer covering the flexible circuit board. Specifically, a flexible conductive layer is added to the adhesive layer, thereby dividing the adhesive layer into two parts. This reduces the thickness of the adhesive layer in direct contact with the copper foil, increases the contact area between the conductive particles and the copper foil after attachment, and makes the flexible conductive layer more flexible and conductive. It is also easier to deform and contact the conductive particles of the upper and lower adhesive layers. The flexible conductive layer can provide a second channel for the transmission of overlapping current, which makes the tape have excellent shielding and grounding effects while greatly improving the vertical and overlapping conductivity. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in this disclosure or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the structure of existing copper foil tape;

[0044] Figure 2 This is a schematic diagram of the structure of a composite film layer according to an embodiment of this application;

[0045] Figure 3 This is a schematic diagram of a current transmission channel according to an embodiment of this application;

[0046] Figure 4 This is a schematic diagram of a cuboid-shaped groove according to an embodiment of this application;

[0047] Figure 5 This is a schematic diagram of a cone-shaped groove according to an embodiment of this application;

[0048] Figure 6 This is a schematic diagram of a hemispherical groove according to an embodiment of this application;

[0049] Figure 7 This is a schematic diagram of a display panel according to an embodiment of this application;

[0050] Figure 8 This is a cross-sectional schematic diagram of a display module according to an embodiment of this application. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0052] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and this application does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0053] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0054] Copper foil tape is widely used inside electronic products such as mobile phones, computers, and monitors to ensure stable signal transmission and reduce electromagnetic leakage. It utilizes the high conductivity of copper (purity above 99.95%) to achieve electrical signal shielding, while the adhesive layer contains conductive materials such as nickel or gold to complete magnetic signal shielding. This effectively isolates electromagnetic interference to equipment and potential harm to the human body. See also... Figure 1 As shown, 100 is the copper foil layer, 200 is the adhesive layer, and 300 is the conductive particles.

[0055] However, copper foil is relatively hard and has poor conformability compared to flexible conductive materials, requiring a thicker adhesive layer. However, thickening the adhesive layer leads to a decrease in conductivity and an increase in lap resistance, affecting its performance. In addition, when the adhesive layer is heated for a long time in bending situations, its adhesion decreases, which can easily cause local peeling from the copper foil, reducing the shielding effect and causing serious screen display distortion.

[0056] The applicant analyzed the aforementioned defects and found that reducing the thickness of the adhesive layer would significantly reduce the fit. The question was whether a conductive structure could be added in the middle of the adhesive layer to reduce its thickness while maintaining stable conductivity. This conductive structure should be made of a flexible or soft conductive material, not a hard material like copper foil.

[0057] If a flexible conductive material with conductive fiber cloth as the main material is used, its stable conductivity can be considered as a direction for improvement. This is because the conductive fiber cloth forms a continuous conductive path by electroplating a polyester fiber substrate with a multi-layer metal structure such as nickel / copper / nickel. Its combination with copper foil can also improve the overall conductivity efficiency and electromagnetic shielding effect (shielding range up to 100K-2.5GHz). The flexibility, wear resistance and high temperature resistance (withstand -30-130℃) of the conductive fiber cloth can make up for the defect of copper foil being easy to tear and extend the service life of copper foil tape in dynamic friction or corrosive environments.

[0058] Based on the above findings, the inventors improved the existing copper foil tape by optimizing its structure into a composite film layer with multiple layers, thereby improving the overall conductivity and electromagnetic shielding effect.

[0059] This application proposes a display module for electronic devices.

[0060] The display module includes a display panel, a flexible circuit board, and a composite film layer.

[0061] The display panel includes a display area and a non-display area located at least on one side of the periphery of the display area. The display area includes pixels arranged in an array, each pixel being configured with a pixel driving circuit. The non-display area is provided with a bonding portion. A flexible circuit board is connected to the bonding portion. A composite film layer is disposed on the flexible circuit board away from the bonding portion to shield at least some of the devices (such as resistors, capacitors, or driver ICs, memory modules, etc.) on it. The composite film layer includes a stacked metal film layer, a first conductive adhesive layer, a flexible conductive layer, and a second conductive adhesive layer. The first conductive adhesive layer contains first conductive particles, and the second conductive adhesive layer contains second conductive particles. The modulus of the first conductive adhesive layer is higher than that of the second conductive adhesive layer, and the density of the first conductive particles in the first conductive adhesive layer is higher than that of the second conductive particles in the second conductive adhesive layer. This design increases the contact area between the conductive particles and the metal film layer (such as a copper foil layer / aluminum foil layer / copper-aluminum alloy layer) after attachment. The conductive nonwoven fabric is softer and more easily deformed to contact the conductive particles above and below, providing a second channel for overlapping current. This improves the shielding effect while avoiding the defect of the copper foil layer peeling off due to heat when bent. The first and second conductive particles are collectively referred to as conductive particles. The flexible circuit board includes an FPC substrate on which electronic components, such as resistors, capacitors, driver ICs, and memory modules, are mounted.

[0062] The composite film layer includes a stacked metal film layer, a first conductive adhesive layer, a flexible conductive layer, and a second conductive adhesive layer. The first conductive adhesive layer contains first conductive particles, and the second conductive adhesive layer contains second conductive particles. The metal film layer can be a copper foil layer, an aluminum foil layer, or a copper-aluminum alloy layer. Preferably, a heat dissipation coating (such as a graphene film) is disposed on the metal film layer away from the first conductive adhesive layer, which improves heat dissipation while providing shielding.

[0063] The following description of the composite film layer proposed in this application will take the copper foil layer (also known as copper foil) as an example of the metal film layer.

[0064] See Figure 2 As shown, the composite film layer includes a copper foil layer 10, a first conductive adhesive layer 20, a flexible conductive layer 30, and a second conductive adhesive layer 40.

[0065] The first surface of the first conductive adhesive layer 20 (i.e., the upper surface of the first conductive adhesive layer) is bonded to the first surface of the copper foil layer 10 (i.e., the lower surface of the copper foil layer), and the second surface of the first conductive adhesive layer 20 (i.e., the lower surface of the first conductive adhesive layer) is bonded to the first surface of the flexible conductive layer 30 (i.e., the upper surface of the flexible conductive layer).

[0066] The second surface (i.e. the lower surface of the flexible conductive layer) of the flexible conductive layer 30 is bonded to the first surface (i.e. the upper surface of the second conductive adhesive layer) of the second conductive adhesive layer 40.

[0067] See Figure 3 As shown, a flexible conductive layer 30 is added between the first conductive adhesive layer 20 and the second conductive adhesive layer 40, splitting the adhesive layer into two parts. This reduces the thickness of the adhesive layer in direct contact with the copper foil 10 layer, increasing the contact area between the conductive particles 60 and the copper foil after adhesion. Since the flexible conductive material of the flexible conductive layer 30 is more flexible than the copper foil material, the conductive particles 60 are more easily deformed and contacted after the flexible conductive layer 30 is bonded to the first conductive adhesive layer 20 and the second conductive adhesive layer 40. One end of the tape is connected to the exposed copper 70, and the other end is connected to the ground 80. The arrow points in the direction of current transmission. Inside the flexible conductive layer 30, another overlapping current transmission channel 90 can be provided, improving the vertical and overlapping conductivity of the tape, while also providing excellent shielding and grounding effects.

[0068] The modulus of the first conductive adhesive layer 20 is higher than that of the second conductive adhesive layer 40, and the thickness of the first conductive adhesive layer 20 is smaller than that of the second conductive adhesive layer 40.

[0069] The density of the conductive particles 60 inside the first conductive adhesive layer 20 is higher than that inside the second conductive adhesive layer 40, which makes the copper foil in the copper foil layer 10 more closely connected with the conductive particles 60 inside the first conductive adhesive layer 20, thereby further stabilizing the shielding grounding effect.

[0070] A denser conductive particle 60 will lead to a poorer adhesion effect of the adhesive layer. The modulus of the first conductive adhesive layer 20 can maintain the cohesive strength to a certain extent and improve the adhesion strength with the flexible conductive layer 30. A thinner thickness makes it easier for the conductive particles 60 of the first conductive adhesive layer 20 to contact and conduct with the copper foil in the copper foil layer 10 and the flexible conductive layer 30. A low film weight of the second conductive adhesive layer 40 results in better initial adhesion and good adhesion and wetting properties with the attached material.

[0071] The surface roughness of the first surface (i.e. the upper surface of the second conductive adhesive layer) of the second conductive adhesive layer 40 is greater than 0.25 μm, which increases the contact area with the second surface of the flexible conductive layer 30, and the second conductive adhesive layer 40 will expose more conductive particles.

[0072] In one embodiment, the flexible conductive material of the flexible conductive layer 30 includes conductive fiber cloth.

[0073] In one embodiment, the conductive fiber cloth includes one of nickel-plated conductive cloth, gold-plated conductive cloth, carbon-plated conductive cloth, or aluminum foil fiber composite cloth;

[0074] In one embodiment, the conductive fiber cloth comprises carbon fibers, such as a polymer resin incorporating conductive or magnetic fillers, including carbon-based fillers, composite conductive fillers, or metal fillers. This flexible conductive layer thus possesses shielding functionality. By combining it with copper foil or copper-aluminum alloy films, its shielding capability is further enhanced, meeting the requirements for high-frequency applications (e.g., electromagnetic shielding in the electromagnetic wave range below 2.5 GHz).

[0075] Preferably, the conductive fiber cloth is a gold-plated conductive cloth;

[0076] Preferably, the conductive fiber cloth is a nickel-plated conductive cloth.

[0077] In one embodiment, the thickness of the first conductive adhesive layer 20 is between 5 and 10 μm, and can be 5 μm, 5.2 μm, 5.5 μm, 5.8 μm, 9.2 μm, 9.5 μm, 9.8 μm or 10 μm;

[0078] Preferably, the thickness of the first conductive adhesive layer 20 is between 6 and 9 μm, and can be 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm or 9 μm;

[0079] Preferably, the thickness of the first conductive adhesive layer 20 is between 7-8 μm, and can be 7.2 μm, 7.4 μm, 7.6 μm or 7.8 μm.

[0080] In one embodiment, the thickness of the second conductive adhesive layer 40 is between 5.5 and 15 μm, and can be 5.5 μm, 5.8 μm, 6 μm, 6.5 μm, 6.8 μm, 7 μm, 7.5 μm, 7.8 μm, 13.2 μm, 13.5 μm, 13.8 μm, 14 μm, 14.2 μm, 14.5 μm, 14.8 μm, or 15 μm;

[0081] Preferably, the thickness of the second conductive adhesive layer 40 is between 8 and 13 μm, and can be 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12.5 μm or 13 μm;

[0082] Preferably, the thickness of the second conductive adhesive layer 40 is between 10-12 μm.

[0083] In one embodiment, the thickness of the copper foil layer 10 is between 9 and 20 μm, and can be 9 μm, 9.5 μm, 9.8 μm, 10.2 μm, 10.8 μm, 11.2 μm, 11.8 μm, 12.2 μm, 12.8 μm, 15.2 μm, 15.8 μm, 16.2 μm, 16.8 μm, 17.2 μm, 17.8 μm, 18.2 μm, 18.5 μm, 18.8 μm, 19 μm, 19.2 μm, 19.5 μm, 19.8 μm, or 20 μm;

[0084] In one embodiment, the thickness of the flexible conductive layer 30 is between 10-15 μm, and can be 10 μm, 10.2 μm, 10.5 μm, 10.8 μm, 11.5 μm, 12.5 μm, 13.5 μm, 14.2 μm, 14.5 μm, 14.8 μm or 15 μm;

[0085] Preferably, the thickness of the flexible conductive layer 30 is between 11 and 14 μm.

[0086] Preferably, the thickness of the flexible conductive layer 30 is between 12-13 μm, and can be 12 μm, 12.2 μm, 12.4 μm, 12.6 μm, 12.8 μm or 13 μm.

[0087] See Figure 4-6 As shown, in one embodiment, a plurality of inwardly oriented grooves 50 are provided on the first surface of the second conductive adhesive layer 40.

[0088] In one embodiment, the groove 50 is provided with a shape that is either a cuboid, a cone, or a hemispherical.

[0089] Preferably, the groove 50 is shaped like a cone, and the cross-section of the cone-shaped groove 50 is an isosceles triangle.

[0090] Preferably, the groove 50 is configured to be cuboid in shape.

[0091] In one embodiment, the copper foil layer 10 is made of electrolytic copper foil, which is anodized to form a nanoscale oxide layer, enhancing the chemical bonding force with the first conductive adhesive layer 20; the first conductive adhesive layer 20 is made of high-modulus epoxy resin (2500MPa) composited with 60 vol% silver-coated copper powder to form a dense conductive network; the flexible conductive layer 30 is made of gold-plated conductive cloth, specifically a combination of chemical nickel plating (0.5μm) and electroplating gold (0.1μm) on the surface of polyester fiber base cloth, with a surface resistivity ≤0.05Ω / sq (ohms per square); the second conductive adhesive layer 40 is made of low-modulus polyurethane acrylate (1200MPa) composited with 35 vol% nickel powder (D50 = 8-12μm), and the surface is laser-engraved with cone-shaped grooves 50.

[0092] In one embodiment, the preparation steps of the copper foil layer 10 include:

[0093] Step 1: Electrolytic copper foil (99.95% purity) is roughened by roller pressing (pressure 50 N / cm). 2 The surface Ra was increased to 0.8-1.0 μm;

[0094] Step 2: Anodizing treatment (voltage 12V, sulfuric acid concentration 5wt%) to form a CuO / Cu2O composite oxide layer.

[0095] The formulation of the first conductive adhesive layer 20 includes epoxy resin E-44 (60wt%) + silver-coated copper powder (40wt%, particle size D50 = 3μm), and its process includes: microgravure coating (anilox roller line count 200LPI), wet film thickness 8μm → dry film thickness after curing 7μm, curing curve 80℃×10min (pre-crosslinking) → 120℃×20min (complete curing) → cooling to 40℃.

[0096] The gold plating process of the flexible conductive layer 30 includes electroless nickel plating (sodium hypophosphite reduction, pH=4.5) → electroplating gold (potassium gold cyanide electrolyte, current density 2A / dm³). 2 Its performance indicators can reach tensile strength ≥80MPa (warp and weft) and surface resistivity ≤0.05Ω / sq.

[0097] The fabrication process of the second conductive adhesive layer 40 includes groove processing: a conical groove (base angle 60°, depth 4μm) is engraved using a CO2 laser (power 25W, scanning speed 150mm / s). Roughness verification: Ra = 0.35±0.05μm is detected by white light interferometer, and the contact angle is reduced from 110° to 65° (to improve wettability).

[0098] The composite film can be obtained by combining the above structures.

[0099] Figure 7This is a schematic diagram of a display panel according to an embodiment of this application.

[0100] The display panel 100 includes a display area 110 and a non-display area 120 that at least partially surrounds one side of the periphery of the display area 110.

[0101] The display area 110 includes an array of light-emitting units, each of which includes multiple pixels, such as red pixels, green pixels, and blue pixels. Each pixel is electrically connected to a pixel driving circuit.

[0102] The non-display area 120 is provided with a bending area 121 and a bonding area 122. The bonding area 122 is used to mount a flexible circuit board in subsequent processes. The flexible circuit board has components such as a main control chip, resistors, capacitors, and other electronic components mounted on it. Preferably, the bonding area is provided with pads. One side of the flexible circuit board has at least one first pad (not shown) for connecting to the pads in the bonding area, and the other side has at least one second pad for soldering connection terminals to connect to the drive module. Preferably, the bonding area mounts an analog drive chip (also called an analog IC, the number of which can be set according to actual needs). The flexible drive component provides drive voltage and data voltage to the analog drive chip. The bonding area 120 can be bent to the back side (the back side of the display area 110) in subsequent processes.

[0103] The display panel 110 also includes:

[0104] The substrate covers the display area and the non-display area. It is a flexible substrate and its material can be selected from materials such as polyimide (PI), polyethylene naphthalate (PEN) or polyethylene terephthalate (PET), or a mixture of the above materials. Alternatively, the substrate 130 can be a rigid substrate, such as glass.

[0105] A driving layer is disposed on the substrate, covering both the display area and the non-display area. This driving layer contains several thin-film transistors and signal traces. The driving layer includes a semiconductor layer, a first metal layer, a second metal layer, a third metal layer, a fourth metal layer, and an interlayer insulating film layer disposed between adjacent conductive film layers. The combination of the semiconductor layer and the traces in the first metal layer forms a transistor; the combination of the traces in the first metal layer and the traces in the second metal layer forms a storage capacitor; and the second, third, and fourth metal layers each contain multiple signal lines with different orientations. Corresponding signal lines are electrically connected to the transistors and storage capacitors, thereby forming a pixel driving circuit and a scan driving circuit.

[0106] A light-emitting layer is disposed on the side of the driving layer away from the substrate 130. The light-emitting layer includes an array of light-emitting units, each of which includes a light-emitting device, which may be an OLED light-emitting device. Part of the signal trace extends to the non-display area and is bonded and electrically connected to the flexible circuit board to receive the electrical signals transmitted therefrom, thereby causing the light-emitting device to emit light.

[0107] like Figure 8 The diagram shows a cross-sectional view of the display module of this application. After the flexible circuit board 130 is mounted on the non-display area 120 of the display panel 100, a composite film layer 140 is attached to it, and then the panel is bent to the back side (exposing the display area or the display area and its surrounding frame when viewed from the front). Sometimes, adhesive tape (not shown) is applied to the composite film layer 140. Preferably, the flexible circuit board 130 is then bent and attached to the surface of the support member 200, which supports the display panel.

[0108] In one embodiment, the orthographic projection of the support member on the display panel side covers the display area and part of the bezel area; the material of the support member may be stainless steel, aluminum or copper or their alloys.

[0109] In one embodiment, the composite film layer includes a stacked metal film layer, a first conductive adhesive layer, a flexible conductive layer, and a second conductive adhesive layer. The thickness of the metal film layer is between 9 and 20 μm. The first conductive adhesive layer contains first conductive particles, and the second conductive adhesive layer contains second conductive particles.

[0110] The thickness of the first conductive adhesive layer is less than or equal to the thickness of the second conductive adhesive layer, and the modulus of the first conductive adhesive layer is higher than that of the second conductive adhesive layer (to improve the bonding strength with the conductive nonwoven fabric). This provides a second channel for current transmission, improving the conductivity of the overlap in the vertical (thickness) direction. Furthermore, the density of the first conductive particles in the first conductive adhesive layer is higher than the density of the second conductive particles in the second conductive adhesive layer.

[0111] Combination Figure 3 and Figure 8Taking copper foil as an example of the metal film layer in the composite film layer, the composite film layer includes a copper foil layer, a first conductive adhesive layer, a flexible conductive layer, and a second conductive adhesive layer stacked sequentially. The second conductive adhesive layer is close to the flexible circuit board 130. In this design, two adhesive layers are set, namely the first conductive adhesive layer and the second conductive adhesive layer, and a conductive non-woven fabric is set in between. This reduces the direct contact thickness between the adhesive layer and the copper foil layer, increases the contact area between the conductive particles and the copper foil after attachment, and combines the conductive non-woven fabric, which is more flexible than the copper foil material, so that the conductive particles are more easily deformed and contacted after the conductive non-woven fabric is bonded to the first conductive adhesive layer and the second conductive adhesive layer. One end is connected to the copper leakage point (also called copper leakage), and the other end is connected to the grounding point. Inside the flexible conductive layer, another overlapping current transmission channel can be provided (the direction of the arrow is the direction of current transmission), which improves the vertical and overlapping conductivity of the composite film layer, and also has excellent shielding and grounding effects. In this embodiment, the density of the first conductive particles inside the first conductive adhesive layer is higher than the density of the second conductive particles inside the second conductive adhesive layer. This results in a tighter contact between the copper foil in the copper foil layer and the first conductive particles 60 inside the first conductive adhesive layer, further stabilizing the shielding grounding effect. The copper foil can be prepared from high-purity electrolytic copper or rolled copper, and its surface may be tin-plated, nickel-plated, or coated with an anti-oxidation layer to improve corrosion resistance. The adhesive layer contains epoxy resin / acrylic adhesive with silver, carbon, or copper particles. This design increases the contact area between the conductive particles and the copper foil after attachment. The conductive nonwoven fabric is more flexible and easier to deform and contact with the conductive particles (such as silver (Ag), copper (Cu), or carbon (C) particles) in the adhesive layers on both sides. This provides a second channel for the lap current, improving the shielding effect while avoiding the defect of peeling caused by decreased adhesion of the copper foil layer when heated in a bent state. Preferably, the adhesive layer uses a combination of acrylic resin and conductive fillers (such as silver (Ag) particles, copper (Cu) particles, or carbon (C) particles), and sometimes a coupling agent (such as a silane coupling agent) is added to improve the adhesion between the resin and the copper foil / substrate; an antioxidant (added when copper (Cu) particles are used to prevent the copper particles from oxidizing and causing an increase in resistivity); and a leveling agent to improve the uniformity of the adhesive layer coating.

[0112] As a variation of the above embodiments, the flexible conductive layer comprises a polymer resin incorporating a conductive or magnetic filler, which may include a carbon-based filler, a composite conductive filler, or a metallic filler. In one embodiment, the carbon-based filler comprises one or a combination of carbon black, carbon fiber, graphene, or carbon nanotubes. Alternatively, the metallic filler may comprise one or a combination of silver, copper, cobalt, or nickel. In another embodiment, the composite conductive filler comprises metallized carbon fiber or nickel-plated carbon nanotubes. Thus, the flexible conductive layer possesses shielding functionality, and its shielding capability is further enhanced by combining it with copper foil or copper-aluminum alloy films, meeting the requirements for electromagnetic shielding in high-frequency applications (such as electromagnetic shielding requirements in the electromagnetic wave range below 2.5 GHz).

[0113] In the above embodiments, in the design of the composite film layer, increasing the modulus of the first conductive adhesive layer can maintain the cohesive strength to a certain extent and improve the adhesion strength with the conductive nonwoven fabric. A thinner thickness makes it easier for the conductive particles to contact and conduct with the copper foil and the conductive nonwoven fabric. A lower film weight of the second conductive adhesive layer results in better initial adhesion and better adhesion and wetting properties with the adhered material. Preferably, a plurality of inwardly oriented grooves are provided on the first surface of the second conductive adhesive layer. The grooves are shaped as a cube, a cone, or a hemisphere to improve adhesion.

[0114] As Figure 3 and Figure 8In a variation of the embodiment, the metal film layer in the composite film layer is aluminum foil. The composite film layer includes sequentially stacked aluminum foil layers, a first conductive adhesive layer, a conductive nonwoven fabric, and a second conductive adhesive layer, with the second conductive adhesive layer close to the flexible circuit board 130. The first and second conductive adhesive layers may respectively contain epoxy resin / acrylic adhesive containing silver, carbon, or copper particles. The flexible conductive layer uses carbon fiber or is mixed with conductive or magnetic fillers, including carbon-based fillers, composite conductive fillers, or metal fillers in polymer resin. This method reduces the thickness of the adhesive layer that directly contacts the metal film layer (copper foil layer), increasing the contact area between the first conductive particles in the first adhesive layer and the copper foil after attachment. Because the flexible conductive material is more flexible than the copper foil material, the conductive particles are more easily deformed and contacted after the flexible conductive layer 30 is bonded to the first and second conductive adhesive layers, improving the vertical and overlapping conductivity (in the thickness direction). By introducing conductive nonwoven fabric to provide a second channel for current transmission, the vertical and overlapping conductivity is improved. The modulus of the first conductive adhesive layer is higher than that of the second conductive adhesive layer, and the thickness of the first conductive adhesive layer is lower than that of the second conductive adhesive layer. This reduces the direct contact thickness between the adhesive layer and the aluminum foil layer, increasing the contact area between the conductive particles and the aluminum foil after adhesion. Combined with conductive nonwoven fabric, which is more flexible than the aluminum foil, the conductive particles can more easily deform and contact after the conductive nonwoven fabric is bonded to the first and second conductive adhesive layers. Connecting one end to the exposed aluminum (also called the aluminum drain) and the other end to the grounding point provides another channel for current transmission within the flexible conductive layer (the arrow points in the direction of current transmission), improving the vertical and overlapping conductivity of the composite film layer, while also providing excellent shielding and grounding effects. Nickel / tin plating is applied to the surface of the aluminum foil to improve its conductivity and corrosion resistance.

[0115] This invention also provides an electronic device including the aforementioned display module. This electronic device can be a flexible OLED tablet, a laptop computer, an AR / VR device, etc. By optimizing the structure of the composite film layer (used to cover at least some components such as resistors, capacitors, or driver ICs, storage modules, etc.) attached to the flexible circuit board in the display module, two adhesive layers are provided with a conductive nonwoven fabric between them. The thickness of the adhesive layer and the conductive nonwoven fabric is lower than that of the other adhesive layer, thus reducing the thickness of the adhesive layer in direct contact with the copper foil layer. By increasing the modulus of the electrical adhesive layer in contact with the copper foil layer, the cohesive strength can be maintained to a certain extent, and the adhesion strength to the conductive nonwoven fabric can be improved. The thinner thickness of the adhesive layer makes it easier for the conductive particles within it to contact and conduct with the copper foil and the conductive nonwoven fabric. The lower film thickness of the other conductive adhesive layer results in better initial adhesion, easier adhesion to the object being attached, and better wettability. Because conductive nonwoven fabric is more flexible, it is easier for it to deform and contact with conductive particles (such as silver (Ag), copper (Cu), or carbon (C) particles) in the bonding layers on both sides, providing a second channel for lap current. This improves the shielding effect while avoiding the defect of peeling caused by decreased adhesion of the copper foil layer due to heat in a bent state. This flexible conductive layer has a shielding function, and its shielding capability is further improved by combining it with copper foil or copper-aluminum alloy film. Even if the copper foil or copper-aluminum alloy film combination cracks, it can still meet the application requirements in high-frequency applications (such as meeting electromagnetic shielding requirements in the electromagnetic wave range below 2.5 GHz), expanding the application range of electronic devices.

[0116] It should be noted that the above description describes some embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0117] This disclosure is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A display module, characterized in that: The display module includes a display panel, a flexible circuit board, and a composite film layer. The display panel includes a display area and a non-display area located at least on one side of the periphery of the display area. The display area includes pixels arranged in an array, and each pixel is configured with a pixel driving circuit; The non-display area is provided with a binding part; The flexible circuit board is connected to the bonding part; The composite film layer is disposed on the flexible circuit board away from the bonding portion to cover at least a portion of the devices thereon. The composite film layer includes a metal film layer, a first conductive adhesive layer, a flexible conductive layer and a second conductive adhesive layer stacked together. The thickness of the metal film layer is between 9-20 μm. The first conductive adhesive layer contains first conductive particles, and the second conductive adhesive layer contains second conductive particles; The thickness of the first conductive adhesive layer is less than or equal to the thickness of the second conductive adhesive layer; Furthermore, the modulus of the first conductive adhesive layer is higher than that of the second conductive adhesive layer.

2. The display module as described in claim 1, characterized in that: The metal film layer is a copper foil layer, and the thickness of the copper foil layer is between 9-20 μm; Preferably, the thickness of the copper foil layer is between 10-18 μm; Preferably, the thickness of the copper foil layer is between 13-15 μm.

3. The display module as described in claim 1, characterized in that: The metal film layer is an aluminum foil layer with a thickness between 9-20 μm; The metal film is a copper-aluminum alloy with a thickness of 9-20 μm.

4. The display module as described in claim 1, characterized in that: The flexible conductive layer includes conductive fiber cloth.

5. The display module as described in claim 4, characterized in that, The conductive fiber cloth includes one or a combination of carbon fiber, nickel-plated conductive cloth, gold-plated conductive cloth, carbon-plated conductive cloth or aluminum foil fiber composite cloth. Preferably, the conductive fiber cloth is a gold-plated conductive cloth; Preferably, the conductive fiber cloth is a nickel-plated conductive cloth.

6. The display module as described in claim 3, characterized in that, The thickness of the flexible conductive layer is between 10-15 μm; Preferably, the thickness of the flexible conductive layer is between 11-14 μm; Preferably, the thickness of the flexible conductive layer is between 12-13 μm.

7. The display module as described in claim 1, characterized in that, The density of the first conductive particles in the first conductive adhesive layer is higher than the density of the second conductive particles in the second conductive adhesive layer. Preferably, the thickness of the first conductive adhesive layer is between 5-10 μm; Preferably, the thickness of the first conductive adhesive layer is between 6-9 μm; Preferably, the thickness of the first conductive adhesive layer is between 7-8 μm.

8. The display module as described in claim 1, characterized in that, The thickness of the second conductive adhesive layer is between 5.5 and 15 μm; Preferably, the thickness of the second conductive adhesive layer is between 8-13 μm; Preferably, the thickness of the second conductive adhesive layer is between 10-12 μm.

9. The display module as described in claim 1, characterized in that, The first surface of the first conductive adhesive layer is bonded to the first surface of the metal film layer, and the second surface of the first conductive adhesive layer is bonded to the first surface of the flexible conductive layer; The first surface of the second conductive adhesive layer is provided with a plurality of inward grooves, and the second surface of the flexible conductive layer is bonded to the first surface of the second conductive adhesive layer; Preferably, the groove is shaped as a cube, a cone, or a hemispherical shape. Preferably, the groove is cone-shaped; Preferably, the thickness of the first conductive adhesive layer is less than the thickness of the second conductive adhesive layer; Preferably, the surface roughness of the first surface of the second conductive adhesive layer is greater than 0.25 μm.

10. An electronic device, characterized in that, The electronic device includes a display module as described in any one of claims 1-9.

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