Display module, preparation method thereof and display device

Abstract

The invention provides a display module, a preparation method thereof and a display device. The display module comprises a display panel, wherein the display panel comprises a display area and a non-display area which is bent to the back surface of the display area; the circuit board is in binding connection with the display panel in the non-display area; the protective layer comprises a first insulating adhesive layer and a conductive adhesive layer which are sequentially arranged in a laminated mode in the direction away from the display panel, and the first insulating adhesive layer and the conductive adhesive layer are formed through the film forming technology. According to the display module, it can be reliably guaranteed that the protective layer can cover the circuit board in a shape-following mode and can be reliably attached to the circuit board, and gaps are avoided, so that the problems that due to the fact that the protective layer cannot be compacted with a product to generate gaps, the waterproof performance of the product is poor, and pressing abnormal sound is generated in use are solved, and the product yield and product competitiveness of the display module are improved.

Description

Technical Field

[0001] The present invention generally relates to the field of display technology, and in particular to a display module and a preparation method thereof, and a display device. Background Art

[0002] In the related art, in order for OLED products to meet the requirements of signal shielding, grounding and heat dissipation of the whole machine, an IC cover tape is usually added above the IC (integrated circuit). Usually, the IC cover tape includes a first insulating Mylar, graphite, conductive cloth / conductive copper foil and a second insulating Mylar stacked together. However, the existing IC cover tape needs to be frequently replaced with the setting of the FPC (flexible circuit board), and cannot be compacted with the product to produce gaps, resulting in poor product waterproof performance, abnormal noise when pressed, and other problems. Summary of the invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a display module, a preparation method and a display device, in which a protective layer is formed on one side of a circuit board through a film forming process, which is conducive to reliably ensuring that the protective layer can cover the circuit board in shape and reliably fit the circuit board to avoid the generation of gaps, thereby solving the problem of gaps caused by the inability to be compacted with the product, resulting in poor waterproof performance of the product and abnormal noise when pressed, thereby improving the product yield and product competitiveness of the display module.

[0004] In a first aspect, the present invention provides a display module, comprising:

[0005] A display panel, the display panel comprising a display area and a non-display area bent to the back of the display area;

[0006] A circuit board, the circuit board is bound and connected to the display panel in the non-display area;

[0007] The protective layer comprises a first insulating adhesive layer and a conductive adhesive layer which are sequentially stacked in a direction away from the display panel, and the first insulating adhesive layer and the conductive adhesive layer are formed by a film forming process.

[0008] As an optional solution, the protective layer further includes a second insulating adhesive layer, which is located on a side of the conductive adhesive layer away from the display panel, and is formed by a film forming process.

[0009] As an optional solution, the protective layer further includes a heat dissipation layer, and the heat dissipation layer is located between the insulating adhesive layer and the conductive adhesive layer;

[0010] As an option, the heat dissipation layer includes graphite.

[0011] As an optional solution, the non-display area includes a binding pad area, the circuit board includes an integrated circuit and a flexible circuit board, and the binding pad area is respectively bound and connected to the integrated circuit and the flexible circuit board.

[0012] As an optional solution, the flexible circuit board also includes a binding area, and the orthographic projection of the insulating adhesive layer on the circuit board at least covers the integrated circuit, the binding area of ​​the flexible circuit board and the binding pad area of ​​the display panel.

[0013] As an optional solution, the flexible circuit board includes a grounding area, and the conductive adhesive layer at least covers the integrated circuit and the grounding area in an orthographic projection on the circuit board.

[0014] As an optional solution, the heat dissipation layer is projected onto the circuit board to cover the integrated circuit.

[0015] In a second aspect, the present invention provides a method for preparing a display module, which specifically comprises the following steps:

[0016] A display panel is provided, the display panel comprises a display area and a non-display area bent to the back of the display area, and the non-display area is bound and connected with a circuit board;

[0017] A protective layer is formed, wherein the protective layer comprises a first insulating adhesive layer and a conductive adhesive layer which are sequentially stacked in a direction away from the display panel, and the first insulating adhesive layer and the conductive adhesive layer are formed by a film forming process.

[0018] As an optional solution, the first insulating adhesive layer and the conductive adhesive layer are formed by a film forming process, including:

[0019] Coating a first insulating adhesive layer slurry and a conductive adhesive layer slurry on a side of the circuit board away from the display panel;

[0020] The first insulating adhesive layer slurry and the conductive adhesive layer slurry are cured to obtain the first insulating adhesive layer and the conductive adhesive layer.

[0021] As an optional solution, the non-display area includes a binding pad area, the circuit board includes an integrated circuit and a flexible circuit board, the flexible circuit board includes a binding area and a grounding area, and the protective layer also includes a second insulating adhesive layer to form a protective layer, including:

[0022] A first insulating adhesive layer is formed on a side of the circuit board away from the display panel by using a film forming process, wherein the orthographic projection of the first insulating adhesive layer on the circuit board at least covers the integrated circuit, the binding area of ​​the flexible circuit board and the binding pad area of ​​the display panel;

[0023] A conductive adhesive layer is formed on the side of the first insulating adhesive layer away from the display panel by using a film forming process, and the conductive adhesive layer covers the integrated circuit and the grounding area on the circuit board in an orthographic projection;

[0024] A second insulating adhesive layer is formed on the side of the conductive adhesive layer away from the display panel by a film forming process. The orthographic projection of the second insulating adhesive layer on the circuit board completely covers the integrated circuit, the area of ​​the flexible circuit board located in the non-display area, and the non-display area.

[0025] As an optional solution, the protective layer further includes a heat dissipation layer. Before forming a conductive adhesive layer on a side of the first insulating adhesive layer away from the display panel by using a film forming process, the method further includes:

[0026] A heat dissipation layer is formed on the side of the first insulating adhesive layer facing away from the display panel, and the orthographic projection of the heat dissipation layer on the circuit board covers the integrated circuit.

[0027] In a third aspect, the present invention provides a display device, comprising the display module of the first aspect and a display module prepared according to the preparation method of the second aspect.

[0028] The display module of the present invention forms a protective layer on the side of the circuit board away from the display panel through a film-forming process. The protective layer includes a first insulating adhesive layer and a conductive adhesive layer stacked in sequence along the direction away from the display panel. The protective layer can reliably protect the circuit board, achieve electrostatic shielding, grounding and heat dissipation effects, and ensure the normal operation of the circuit board. On the one hand, the first insulating adhesive layer and the conductive adhesive layer in the present invention are formed through a film-forming process, and the appearance can be arbitrarily changed according to product changes without frequent replacement. Compared with the existing IC Cover Tape, the cost is low. On the other hand, forming the first insulating adhesive layer and the conductive adhesive layer through a film-forming process is conducive to the perfect fit of the protective layer material and the circuit board, and achieving seamless contact as much as possible, thereby improving the waterproof performance and avoiding the problem of abnormal noise when pressing during use, thereby improving the product yield and product competitiveness of the display module. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0030] Figure 1 It is a cross-sectional structural diagram of a display module in the prior art;

[0031] Figure 2 It is a front view schematic diagram of an IC Cover Tape covering an IC in a display module of the prior art;

[0032] Figure 3 It is a front view schematic diagram of an IC Cover Tape covering an IC in another display module of the prior art;

[0033] Figure 4 A schematic cross-sectional structure diagram of a display module according to an embodiment of the present application;

[0034] Figure 5 is a schematic cross-sectional structure diagram of another display module in an embodiment of the present application;

[0035] Figure 6 The present invention is a schematic diagram of a manufacturing process of a display module according to an embodiment of the present invention; wherein (a) is a display panel after being folded and bent; (b) is an insulating adhesive layer formed; (c) is a conductive adhesive layer formed;

[0036] Figure 7 Schematic diagram of another process of preparing a display module according to an embodiment of the present application; wherein (a) is after the display panel is folded and bent; (b) a first insulating adhesive layer is formed; (c) a conductive adhesive layer is formed; (d) a second insulating adhesive layer is formed;

[0037] Figure 8 This is a schematic diagram of the preparation process of another display module of an embodiment of the present application; wherein, (a) is the display panel after being folded and bent; (b) forming a first insulating adhesive layer; (c) forming a heat dissipation layer; (d) forming a conductive adhesive layer; and (e) forming a second insulating adhesive layer.

[0038] In the figure,

[0039] 100. Display module;

[0040] 1. First insulation Mylar glue, 2. Graphite, 3. Conductive cloth / conductive copper foil, 4. Second insulation Mylar glue, 5. Gap;

[0041] 10. Display panel, 11. Metal protective glue, 20. Circuit board, 21. Electronic components, 22. Integrated circuit, 23. Flexible circuit board, 231. Grounding area,

[0042] 30, protective layer, 311, first insulating rubber layer, 312, second insulating rubber layer, 32, conductive rubber layer, 33, heat dissipation layer;

[0043] 40. cover plate, 50. optical adhesive, 60. polarizer, 70. back film, 80. heat dissipation film, 90. bending support layer. DETAILED DESCRIPTION

[0044] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0045] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] In the related art, in order for OLED products to meet the requirements of signal shielding, grounding, and heat dissipation of the entire device, an IC cover tape is usually added above the IC (integrated circuit). Figure 1 As shown, the common IC cover tape includes a first insulating Mylar glue 1, graphite 2, conductive cloth / conductive copper foil 3 and a second insulating Mylar glue 4 which are stacked. In actual use, according to the customer's demand for the product, it can also be adjusted to a stacked graphite, conductive cloth / conductive copper foil, insulating Mylar glue and UV insulating glue; or a stacked graphite, insulating Mylar glue and UV insulating glue; or a stacked graphite and insulating Mylar glue. Among them, the insulating Mylar glue is commonly used as PET with adhesive on one side and a black coating on the other side; the conductive copper foil is copper foil with conductive adhesive on one side; and the conductive cloth is fabric with conductive adhesive on one side.

[0047] However, the existing IC cover tape has the following problems during use: (1) Due to changes in the shape / grounding of the flexible circuit board (FPC), the IC cover tape needs to be changed frequently, resulting in a waste of die cutting costs; (2) The IC cover tape is affected by the die-cutting accuracy and the bonding accuracy. The current accuracy is ±0.5mm, and it needs to avoid the components and cannot be tightly bonded; (3) There is a gap of 5 after the IC cover tape covers the components. When the folding screen is used, there is a poor pressing sound; (4) The IC cover tape material has a minimum width limit for bonding. If it is too narrow, there will be wrinkles after bonding. The narrowest width is currently 3mm; (5) After the IC cover tape material is covered, the bonding jig cannot press the IC cover tape and the product, thus affecting the waterproof ability. Figure 2 As shown, in an existing IC cover tape, since the reserved space on the display module is small, in order to ensure no wrinkles, the IC cover tape is designed to be redundant, and part of it can only be suspended in the air without any application; Figure 3 As shown, there is another type of IC cover tape. Since the reserved space on the display module is small, in order to ensure that there are no wrinkles, the IC Cover Tape can only not cover part of the FPC area.

[0048] Based on the above problems, an embodiment of the present application provides a display module 100, such as Figure 4 and 5 As shown, including:

[0049] A display panel 10, the display panel 10 includes a display area and a non-display area bent to the back of the display area;

[0050] A circuit board 20, the circuit board 20 is bound and connected to the display panel 10 in the non-display area;

[0051] The protective layer 30 includes a first insulating adhesive layer 311 and a conductive adhesive layer 32 which are sequentially stacked along a direction away from the display panel 10 . The first insulating adhesive layer 311 and the conductive adhesive layer 32 are formed by a film forming process.

[0052] It should be noted that the display panel 10 in the embodiment of the present application may be a curved display panel 10, wherein the curved display panel includes a display panel in the middle that is in a flat state, and part or all of the edges of the display panel 10 are in a curved state. The display panel 10 includes a display area and a non-display area bent to the back of the display area, and a curved support layer 90 is provided between the non-display area bent to the back of the display area and the back of the display area, and the non-display area includes a binding pad area and an area for installing other structures. Among them, the non-display area may include a binding pad area. Of course, according to actual process requirements, two binding pad areas or more binding pad areas can be provided in the non-display area.

[0053] Among them, the circuit board 20 may include a flexible circuit board 23 and a rigid circuit board 20, and electronic components 21 are arranged on the circuit board 20, and the electronic components 21 are electrically connected to the circuit board 20. The circuit board 20 is bound and connected to the display panel 10 in the non-display area. Specifically, the circuit board 20 is bound and connected to the binding pad area of ​​the display panel 10.

[0054] It can be understood that the protective layer 30 includes a first insulating adhesive layer 311 and a conductive adhesive layer 32. Among them, the first insulating adhesive layer 311 is mainly used to protect the circuit board 20, prevent water vapor from penetrating and avoid contact with other conductive structures to cause adverse problems. The first insulating adhesive layer 311 can be, but not limited to, a thermosetting insulating adhesive or a light-curing insulating adhesive, etc. The first insulating adhesive layer 311 is generally in a flowable state and is cured into a film after heating or light exposure; the conductive adhesive layer 32 is mainly used to achieve the function of shielding static electricity and achieving the function of grounding the circuit board 20, so as to ensure that the circuit board 20 can work normally; the conductive adhesive layer 32 can be, but not limited to, a thermosetting conductive adhesive or a light-curing conductive adhesive, and the conductive adhesive layer 32 is generally in a flowable state and is cured into a film after heating or light exposure. The first insulating adhesive layer 311 and the conductive adhesive layer 32 in the embodiment of the present application are conveniently formed on the side of the circuit board 20 away from the display panel 10. Since the first insulating adhesive layer 311 and the conductive adhesive layer 32 have a certain fluidity, they can be covered on the circuit board 20 in a conforming manner. After curing into a film, gaps between the circuit board 20 and the circuit board 20 can be avoided, thereby improving the processing quality and good quality of the display module.

[0055] For example, the conductive adhesive layer 32 may be UV conductive adhesive, and the first insulating adhesive layer 311 may be UV insulating adhesive.

[0056] It can also be understood that the film forming process may include coating and curing processes; specifically, the coating process refers to coating the first insulating adhesive layer 311 or the conductive adhesive layer 32 on the circuit board 20 by, but not limited to, spraying, scraping or spin coating; the curing process refers to curing the coated first insulating adhesive layer 311 or the conductive adhesive layer 32 into a non-flowing state to form a film layer by heating or other methods such as light.

[0057] The display module of the embodiment of the present application solves the problem that the IC Cover Tape set on the circuit board 20 in the display module in the prior art cannot be compacted with the product to produce a gap, resulting in poor waterproof performance of the product and abnormal noise when pressed. The display module of the embodiment of the present application forms a protective layer 30 on the side of the circuit board 20 away from the display panel 10 through a film forming process. The protective layer 30 includes a first insulating adhesive layer 311 and a conductive adhesive layer 32 stacked in sequence along the direction away from the display panel 10. The protective layer 30 can reliably protect the circuit board 20, achieve electrostatic shielding, grounding and heat dissipation effects, and ensure the normal operation of the circuit board 20. On the one hand, the protective layer 30 in the present invention is formed by a film forming process, and the shape can be arbitrarily changed according to product changes, without frequent replacement, and the cost is lower than that of the existing IC Cover Tape. On the other hand, the formation of the first insulating layer 311 and the conductive adhesive layer 32 through a film forming process is conducive to the perfect fit of the protective layer 30 material and the circuit board 20, and to achieve seamless contact as much as possible, thereby improving the waterproof performance and avoiding the problem of abnormal noise when pressed during use, thereby improving the product yield and product competitiveness of the display module.

[0058] In some embodiments, Figure 4 and 5 As shown, the display module may further include a polarizer 60 and a cover plate 40 . The polarizer 60 is disposed on the light emitting side of the display panel 10 , and the cover plate 40 is attached to the side of the polarizer 60 away from the display panel 10 through an optical adhesive 50 (OCA).

[0059] Among them, the polarizer 60 is mainly used to shield the emission of ambient light irradiated into the interior of the display panel 10, so as to achieve an anti-reflection effect. Generally, the polarizer 60 may include a hard coating (HC), TAC (triacetate), a polarizing layer (PVA), a first photosensitive adhesive layer (PSA), an ND film, and a second photosensitive adhesive layer (PSA) stacked in sequence; in actual use, the polarizer 60 also includes an upper protective film and a lower protective film, the upper protective film is arranged above the hard coating, and the lower protective film is arranged below the second photosensitive adhesive layer. When the polarizer 60 is installed on the display panel 10, the upper protective film and the lower protective film need to be torn off first, and then the second photosensitive adhesive layer is attached to the display panel 10.

[0060] The cover plate 40 is mainly used to protect the entire display module. The cover plate 40 is bonded to the side of the polarizer 60 away from the display panel 10 through a transparent optical adhesive 50 (Optically Clear Adhesive). The cover plate 40 can be, but is not limited to, glass or transparent resin material and PET, etc., as long as it has good light transmittance, and the embodiments of the present application do not make specific limitations on this. Taking glass as an example, when applied to curved display products, at least one side of the cover plate 40 is bent, and the bonding of the layers of the display module is achieved through a 3D bonding process.

[0061] In some embodiments, the display module also includes a back film 70, a metal protective glue 11 and a heat dissipation film 80. The back film 70 and the heat dissipation film 80 are stacked on the backlight side of the display panel 10 along a direction away from the display panel 10. The metal protective glue 11 (Metal Coating layers, MCL for short) is adhered to the outer side of the curved portion of the display panel 10 and is mainly used to protect the curved portion of the display panel 10.

[0062] The back film 70 may 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 70 may include a laminated acrylic film (Acryl film) and a polyethylene terephthalate film (PET film).

[0063] The heat dissipation film 80 is located on the side of the back film 70 away from the display panel 10. The heat dissipation film 80 can be made of a superclean foam (SCF) composite film; of course, the heat dissipation film 80 can also adopt a multi-layer laminated structure, wherein the heat dissipation film 80 includes a metal layer, the metal has heat dissipation performance and conductive performance, and the metal layer can generally use metal copper (Cu) or metal aluminum (Al); the heat dissipation film 80 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 80 to the backlight side of the display panel 10, the adhesive layer can use mesh glue (embossing, referred to as EMBO) or other adhesive materials, the mesh glue is beneficial to reduce the bubbles generated when bonding with the display panel 10, thereby enhancing the connection strength between the display panel 10 and the heat dissipation film 80. During actual use, a protective film layer is provided on the side of the adhesive layer of the heat dissipation film 80 that is away from the metal layer, which is used to protect the film layer. When using the heat dissipation film 80, the protective film layer needs to be peeled off first; the functional layer has a stress buffering property, which can buffer the stress and impact applied to the display panel 10 by the outside; specifically, the functional layer may include a foam layer (Foam), which is provided on the side of the adhesive layer close to the metal layer, and the material of the foam layer may be polyurethane (PU for short) or other materials; in some other embodiments, the functional layer may also include a supporting layer, which is provided on the side of the foam layer close to the metal layer to play a supporting and impact-resistant role, and the supporting layer may be black to enhance the integrated black effect of the product, and the supporting layer may be black PI (Polyimide).

[0064] As an achievable method, Figure 5 As shown, the protection layer 30 further includes a second insulating adhesive layer 312 , and the conductive adhesive layer 32 is located between the first insulating adhesive layer 311 and the second insulating adhesive layer 312 .

[0065] The first insulating adhesive layer 311 and the second insulating adhesive layer 312 may be made of the same insulating adhesive; of course, the first insulating adhesive layer 311 and the second insulating adhesive layer 312 may also be made of different insulating adhesives.

[0066] In actual processing, the covering position of the first insulating adhesive layer 311 and the covering position of the second insulating adhesive layer 312 overlap (i.e., completely overlap or partially overlap). The covering position can be understood as the positive projection on the circuit board 20. For example, the first insulating adhesive layer 311 can only cover part of the area on the circuit board 20, leaving part of the conductive area and the grounding area 231 to facilitate the setting of the conductive adhesive layer 32. The conductive adhesive layer 32 at least covers the grounding area 231 to achieve grounding and shielding. The second insulating adhesive layer 312 covers the entire first insulating adhesive layer 311 and the conductive adhesive layer 32 as well as other areas on the circuit board 20 that need to be protected, further improving the protection performance.

[0067] In this embodiment, two layers of protective adhesive are provided, which is conducive to facilitating the provision of the conductive adhesive layer 32 and is also conducive to improving the insulation protection capability of the circuit board 20 .

[0068] As an achievable method, Figure 5 As shown, the protection layer 30 further includes a heat dissipation layer 33 , and the heat dissipation layer 33 is located between the first insulating adhesive layer 311 and the conductive adhesive layer 32 .

[0069] Specifically, the heat dissipation layer 33 is located on a side of the first insulating adhesive layer 311 away from the display panel 10 . The heat dissipation layer 33 is mainly used to improve the heat dissipation effect of the circuit board 20 to ensure that the circuit board 20 can work reliably.

[0070] The heat dissipation layer 33 can be any carbon material with good heat dissipation performance, such as but not limited to graphite, graphene or carbon black.

[0071] In this embodiment, the protective layer 30 includes a heat dissipation layer 33 , which is beneficial to further improve the heat dissipation capacity of the protective layer 30 , further avoid overheating of the circuit board 20 , and ensure the normal operation of the circuit board 20 .

[0072] In a preferred embodiment, the heat dissipation layer 33 comprises graphite.

[0073] In some embodiments, the non-display area includes a binding pad area, the circuit board 20 includes an integrated circuit 22 and a flexible circuit board 23, and the binding pad area is respectively bound and connected to the flexible circuit board 23 and the integrated circuit 22.

[0074] Among them, a driving chip can be connected to the flexible circuit board 23, and the driving chip can be used to drive the display panel 10 to emit light. A power management chip, a timing control chip, a gamma correction chip, etc. can be set on the integrated circuit 22, and the power management chip, the timing control chip, the gamma correction chip, etc. are electrically connected to the integrated circuit 22.

[0075] The integrated circuit 22 is bound and connected to the binding pad area of ​​the display panel 10 , and the binding pad area of ​​the display panel 10 is bound and connected to the flexible circuit board 23 , so as to realize electrical connection, thereby reliably controlling the display panel 10 to emit light.

[0076] As a way to achieve this, Figure 6-8 As shown, the flexible circuit board 23 includes a grounding area 231 , and the conductive adhesive layer 32 at least covers the integrated circuit 22 and the grounding area 231 in an orthographic projection on the circuit board 20 .

[0077] The covering position of the conductive adhesive layer 32 in this embodiment is conducive to reliably realizing the electrostatic shielding of the integrated circuit 22 and the grounding of the flexible circuit board 23 .

[0078] In some embodiments, the conductive adhesive layer 32 may also cover other areas of the non-display area of ​​the display panel 10 except for the integrated circuit 22 and the grounding area 231 of the flexible circuit board 23 .

[0079] As an implementable manner, the heat dissipation layer 33 covers the integrated circuit 22 in an orthographic projection on the circuit board 20 .

[0080] Since there are many components on the integrated circuit 22 during the operation of the display module, it is easy to generate a lot of heat. In this embodiment, a heat dissipation layer 33 is provided on the integrated circuit 22 to improve the heat dissipation capacity and ensure the reliable operation of the integrated circuit 22.

[0081] In some embodiments, the flexible circuit board 23 further includes a binding area, and the orthographic projection of the first insulating adhesive layer 311 on the circuit board 20 at least covers the integrated circuit 22 , the binding area of ​​the flexible circuit board 23 and the binding pad area of ​​the display panel 10 .

[0082] In this embodiment, the first insulating adhesive layer 311 covers the integrated circuit 22, the binding area of ​​the flexible circuit board 23 and the binding pad area of ​​the display panel 10, which is conducive to reliable insulation protection and prevents water vapor intrusion, thereby ensuring reliable operation of the circuit board 20.

[0083] It is understandable that the first insulating adhesive layer 311 may also cover the entire flexible circuit except for the connector area, the integrated circuit 22 and the non-display area of ​​the display panel 10 , which is specifically determined according to actual processing requirements.

[0084] In summary, the display module of the embodiment of the present application forms a protective layer 30 on the side of the circuit board 20 away from the display panel 10 through a film forming process. The protective layer 30 includes a first insulating adhesive layer 311 and a conductive adhesive layer 32 stacked in sequence along the direction away from the display panel 10. The protective layer 30 can reliably protect the circuit board 20, achieve electrostatic shielding, grounding and heat dissipation effects, and ensure the normal operation of the circuit board 20. On the one hand, the protective layer 30 in the present invention is formed through a film forming process, and its appearance can be arbitrarily changed according to product changes without frequent replacement. Compared with the existing IC Cover Tape, the cost is low. On the other hand, forming the first insulating protective layer and the conductive adhesive layer through a film forming process is conducive to the perfect fit of the protective layer 30 material and the circuit board 20, and achieving seamless contact as much as possible, thereby improving the waterproof performance and avoiding the problem of abnormal sound when pressed during use, thereby improving the product yield and product competitiveness of the display module;

[0085] In addition, the protective layer 30 also includes a heat dissipation layer 33, which is beneficial to improving the heat dissipation capacity of the circuit board 20 and ensuring the normal and reliable operation of the circuit board 20; the first insulating rubber layer 311 includes a first insulating rubber layer 311 and a second insulating rubber layer 312, which is beneficial to facilitate the setting of the conductive rubber layer 32 and at the same time is beneficial to improving the insulation protection capability of the circuit board 20.

[0086] In a second aspect, an embodiment of the present application provides a method for preparing a display module, such as Figure 6 As shown, the specific steps include:

[0087] Step S10, providing a display panel 10, the display panel 10 comprising a display area and a non-display area bent to the back of the display area, and the non-display area is bound and connected to a circuit board 20;

[0088] Step S20 , forming a protective layer 30 , the protective layer 30 includes a first insulating adhesive layer 311 and a conductive adhesive layer 32 stacked in sequence along a direction away from the display panel 10 , and the first insulating adhesive layer 311 and the conductive adhesive layer 32 are formed by a film forming process.

[0089] The embodiment of the present application forms the protective layer 30 through a film forming process. The shape of the protective layer 30 can be changed arbitrarily according to product changes, and there is no need for frequent replacement. Compared with the existing IC Cover Tape, the cost is low, and there is no need to use die cutting, and there is no need to consider the die cutting accuracy. On the other hand, forming the protective layer 30 through a film forming process is conducive to the perfect fit between the protective layer 30 material and the circuit board 20, and achieving seamless contact as much as possible, thereby improving the waterproof performance and avoiding the problem of abnormal noise when pressing during use, thereby improving the product yield and product competitiveness of the display module.

[0090] In some embodiments, step S20, forming the first insulating adhesive layer 311 and the conductive adhesive layer 32 by using a film forming process, includes:

[0091] A first insulating adhesive layer 311 slurry and a conductive adhesive layer 32 slurry are coated on a side of the circuit board 20 away from the display panel 10 ;

[0092] The slurry of the first insulating adhesive layer 311 and the slurry of the conductive adhesive layer 32 are cured to obtain the first insulating adhesive layer 311 and the conductive adhesive layer 32 .

[0093] In this embodiment, the coating method may be, but is not limited to, spray coating, scraping coating, or spin coating; the curing method may be, but is not limited to, heating or light irradiation.

[0094] In this embodiment, the film forming process is simple to operate and convenient to process, and can reliably ensure that the protective layer 30 and the circuit board 20 fit perfectly without any gap.

[0095] In some embodiments, the non-display area includes a bonding pad area, the circuit board 20 includes an integrated circuit 22 and a flexible circuit board 23, the flexible circuit board 23 includes a bonding area and a grounding area 231, the protective layer 30 also includes a second insulating adhesive layer 312, step S20, forming the protective layer 30, such as Figure 7 As shown, including:

[0096] A first insulating adhesive layer 311 is formed on the side of the circuit board 20 away from the display panel 10 by using a film forming process, and the orthographic projection of the first insulating adhesive layer 311 on the circuit board 20 at least covers the integrated circuit 22, the binding area of ​​the flexible circuit board 23 and the binding pad area of ​​the display panel 10;

[0097] A conductive adhesive layer 32 is formed on the side of the first insulating adhesive layer 311 away from the display panel 10 by using a film forming process, and the conductive adhesive layer 32 covers the integrated circuit 22 and the grounding area 231 on the circuit board 20 in an orthographic projection;

[0098] A second insulating adhesive layer 312 is formed on the side of the conductive adhesive layer 32 facing away from the display panel 10 by a film forming process. The orthographic projection of the second insulating adhesive layer 312 on the circuit board 20 completely covers the integrated circuit 22, the area of ​​the flexible circuit board 23 located in the non-display area, and the non-display area of ​​the display panel 10.

[0099] In this embodiment, the formed protective layer 30 includes a first insulating adhesive layer 311, a conductive adhesive layer 32 and a second insulating adhesive layer 312. The first insulating adhesive layer 311 realizes insulation protection while leaving part of the conductive area and the grounding area 231, which is convenient for the arrangement of the conductive adhesive layer 32. The conductive adhesive layer 32 at least covers the grounding area 231 to achieve grounding and shielding. The second insulating adhesive layer 312 covers the entire first insulating adhesive layer 311 and the conductive adhesive layer 32 as well as other areas on the circuit board 20 that need to be protected, further improving the protection performance.

[0100] In some other embodiments, the protective layer 30 further includes a heat dissipation layer 33. In step S20, before forming the conductive adhesive layer 32 on the side of the first insulating adhesive layer 311 away from the display panel 10 by using a film forming process, Figure 8 As shown, the method also includes:

[0101] A heat dissipation layer 33 is formed on a side of the first insulating adhesive layer 311 facing away from the display panel 10 . The orthographic projection of the heat dissipation layer 33 on the circuit board 20 covers the integrated circuit 22 .

[0102] The heat dissipation layer 33 may be any carbon material with good heat dissipation performance, such as but not limited to graphite, graphene or carbon black.

[0103] The protective layer 30 in this embodiment includes a heat dissipation layer 33 , which is beneficial to further improve the heat dissipation capacity of the protective layer 30 , further avoid overheating of the circuit board 20 , and ensure the normal operation of the circuit board 20 .

[0104] In summary, the preparation method of the display module of the present application is simple to operate, and can ensure seamless contact between the protective layer 30 and the circuit board 20, thereby ensuring that the display module has good waterproof performance, while avoiding the problem of abnormal noise when the display module is pressed during use, further improving the product yield and product competitiveness of the display module.

[0105] The following describes the method for preparing the display module of the present application through specific embodiments.

[0106] Example 1

[0107] like Figure 6 As shown in a, after the display module is folded, the flexible circuit board 23 of the display module has been bound, and the polarizer 60, optical glue 50, cover plate 40, back film 70 and heat dissipation film 80 on the back of the display panel are all bonded;

[0108] like Figure 6 As shown in step b, UV-type insulating adhesive is coated and cured on the side of the integrated circuit 22 and the flexible circuit board 23 away from the display panel 10, as well as on the binding area of ​​the flexible circuit board, to form a first insulating adhesive layer 311;

[0109] like Figure 6 As shown in c, UV conductive glue is coated on the first insulating glue layer 311 and other areas of the flexible circuit board 23 on the side away from the display panel 10 and cured to form a conductive glue layer 32;

[0110] Example 2

[0111] The difference from Example 1 is that: Figure 7As shown in ab, UV type insulating glue is coated and cured on the side of the integrated circuit 22 and the flexible circuit board 23 away from the display panel 10, as well as the binding area of ​​the flexible circuit board, to form a first insulating glue layer 311;

[0112] like Figure 7 As shown in c, UV conductive glue is coated on the first insulating glue layer 311 and other required areas of the flexible circuit board 23 on the side away from the display panel 10 and cured to form a conductive glue layer 32;

[0113] like Figure 7 As shown in FIG. d , UV insulating adhesive is coated on the conductive adhesive layer 32 and other required areas to form a second insulating adhesive layer 312 .

[0114] Example 3

[0115] Different from Example 2, Figure 8 As shown in Fig. ac, after the first insulating adhesive layer 311 is formed, graphite is applied to the area corresponding to the integrated circuit 22 on the side of the first insulating adhesive layer 311 away from the display panel 10 to form a heat dissipation layer 33;

[0116] like Figure 8 As shown in FIG. d, UV conductive glue is coated on the first insulating glue layer 311, the heat dissipation layer 33 and other required areas of the flexible circuit board 23 on the side away from the display panel 10 and cured to form a conductive glue layer 32;

[0117] like Figure 8 As shown in FIG. 4 , UV insulating adhesive is coated on the conductive adhesive layer 32 and other required areas to form a second insulating adhesive layer 312 .

[0118] In a third aspect, an embodiment of the present application provides a display device, comprising the display module of the first aspect and the display module prepared according to the preparation method of the second aspect. It is understandable that the display device has all the features and advantages of the above-mentioned display module, which will not be repeated here. In short, the display device has high quality and yield rate and good display effect.

[0119] The display device is a product with an image display function. For example, the display device may be: a display, a television, a billboard, a digital photo frame, a laser printer with a display function, a telephone, a mobile phone, a personal digital assistant (PDA), a digital camera, a camcorder, a viewfinder, a navigator, a vehicle, a large-area wall, a home appliance, an information query device (such as business query equipment of e-government, banks, hospitals, power and other departments), a monitor, etc. The display device may also be a microdisplay or a product containing a microdisplay. The product containing a microdisplay may be a smart watch, a smart bracelet, a helmet display, a stereo display mirror, and any of AR devices (such as AR glasses), VR devices (such as VR glasses), etc. For example, a microdisplay may be a display with a display size ranging from about 0.2 inches to about 2.5 inches, but is not limited thereto. It can be understood that the microdisplay may also be a display with a smaller display size, such as a display size less than or equal to 0.2 inches.

[0120] It should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used above to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the panel or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0121] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A display module, characterized in that: include: A display panel, the display panel comprising a display area and a non-display area bent to the back of the display area; A circuit board, wherein the circuit board is bound and connected to the display panel in the non-display area; The protective layer includes a first insulating adhesive layer and a conductive adhesive layer which are sequentially stacked in a direction away from the display panel, and the first insulating adhesive layer and the conductive adhesive layer are formed by a film forming process.

2. The display module according to claim 1, characterized in that: The protection layer further includes a second insulating adhesive layer, which is located on a side of the conductive adhesive layer away from the display panel, and is formed by a film forming process.

3. The display module according to claim 1, characterized in that: The protective layer also includes a heat dissipation layer, and the heat dissipation layer is located between the insulating adhesive layer and the conductive adhesive layer; Preferably, the heat dissipation layer comprises graphite.

4. The display module according to any one of claims 1 to 3, characterized in that: The non-display area includes a binding pad area, the circuit board includes an integrated circuit and a flexible circuit board, and the binding pad area is respectively bound and connected to the integrated circuit and the flexible circuit board.

5. The display module according to claim 4, characterized in that: The flexible circuit board includes a binding area, and the orthographic projection of the first insulating adhesive layer on the circuit board at least covers the integrated circuit, the binding area of ​​the flexible circuit board and the binding pad area of ​​the display panel.

6. The display module according to claim 5, characterized in that: The flexible circuit board also includes a grounding area, and the conductive adhesive layer at least covers the integrated circuit and the grounding area in an orthographic projection on the circuit board.

7. The display module according to claim 4, characterized in that: The orthographic projection of the heat dissipation layer on the circuit board covers the integrated circuit.

8. A method for preparing a display module, characterized in that: The specific steps include: A display panel is provided, wherein the display panel comprises a display area and a non-display area bent to the back of the display area, and the non-display area is bound and connected to a circuit board; A protective layer is formed, wherein the protective layer comprises a first insulating adhesive layer and a conductive adhesive layer which are sequentially stacked in a direction away from the display panel, and the first insulating adhesive layer and the conductive adhesive layer are formed by a film forming process.

9. The method for preparing a display module according to claim 8, characterized in that: The first insulating adhesive layer and the conductive adhesive layer are formed by a film forming process, including: Coating the first insulating adhesive layer slurry and the conductive adhesive layer slurry on a side of the circuit board away from the display panel; The first insulating adhesive layer slurry and the conductive adhesive layer slurry are cured to obtain the first insulating adhesive layer and the conductive adhesive layer.

10. The method for preparing a display module according to claim 8, characterized in that: The non-display area includes a bonding pad area, the circuit board includes an integrated circuit and a flexible circuit board, the flexible circuit board includes a bonding area and a grounding area, the protective layer also includes a second insulating adhesive layer, and the protective layer is formed, including: A first insulating adhesive layer is formed on a side of the circuit board away from the display panel by using a film forming process, wherein the orthographic projection of the first insulating adhesive layer on the circuit board at least covers the integrated circuit, the binding area of ​​the flexible circuit board and the binding pad area of ​​the display panel; The conductive adhesive layer is formed on the side of the first insulating adhesive layer away from the display panel by using a film forming process, and the orthographic projection of the conductive adhesive layer on the circuit board covers the integrated circuit and the grounding area; The second insulating adhesive layer is formed on the side of the conductive adhesive layer away from the display panel by using a film forming process, and the orthographic projection of the second insulating adhesive layer on the circuit board completely covers the integrated circuit, the area of ​​the flexible circuit board located in the non-display area, and the non-display area.

11. The method for preparing a display module according to claim 8 or 10, characterized in that: The protective layer further includes a heat dissipation layer. Before forming the conductive adhesive layer on a side of the first insulating adhesive layer away from the display panel by using a film forming process, the method further includes: A heat dissipation layer is formed on a side of the first insulating adhesive layer facing away from the display panel, and the orthographic projection of the heat dissipation layer on the circuit board covers the integrated circuit.

12. A display device, characterized in that The invention comprises the display module according to any one of claims 1 to 7 or the display module prepared according to the preparation method according to any one of claims 8 to 11.

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