Manufacturing method of display module

Abstract

The application discloses a display module manufacturing method, comprising the following steps: providing a driving backboard, a conductive adhesive film is formed on one side surface of the driving backboard, and the conductive adhesive film has a plurality of conductive particles; a plurality of light emitting elements are pre-fixed to the conductive adhesive film through pins thereof, and the plurality of light emitting elements are located on the side of the conductive adhesive film away from the driving backboard; a fixing film layer is formed, at least part of each light emitting element is covered by the fixing film layer, and the fixing film layer covers at least the surface of the side of the plurality of light emitting elements away from the conductive adhesive film; the fixing film layer is subjected to pressure, the conductive adhesive film is heated, the conductive adhesive film is deformed, the conductive particles in the conductive adhesive film electrically connect the light emitting elements and the driving backboard, and the conductive adhesive film starts to solidify when heated to a first temperature. The display module manufacturing method provided by the application improves the electrical connection yield of the light emitting elements and the driving backboard.

Description

Technical Field

[0001] This application belongs to the field of display technology, and in particular relates to a method for manufacturing a display module. Background Technology

[0002] Micro-LED displays are miniaturized light-emitting diode arrays. This involves designing, miniaturizing, and arraying light-emitting diodes (LEDs), then mass-producing them onto a driving backplane. A protective layer is then created using physical deposition technology, resulting in miniaturized LEDs with nanometer-scale spacing. Compared to LCD and OLED displays, micro-LED displays offer higher brightness and efficiency, shorter response times, longer lifespans, and a wider operating range. They are considered the ultimate display technology and can be applied to televisions, augmented reality (AR) and virtual reality (VR) technologies, automotive displays, wearable devices, and smartphones.

[0003] After miniaturized light-emitting diodes are mass-produced and transferred to the driver backplane, the electrical connection yield between the miniaturized light-emitting diodes and the driver backplane is affected during the fixing process because at least some of the miniaturized light-emitting diodes have different thicknesses. Summary of the Invention

[0004] This application provides a method for manufacturing a display module, which improves the manufacturing yield of the display module.

[0005] This application provides a method for manufacturing a display module, the display module including a driving backplate and multiple light-emitting elements, the manufacturing method including the following steps:

[0006] S10: Provide a drive backplate, wherein a conductive adhesive film is formed on one side surface of the drive backplate, and the conductive adhesive film has a plurality of conductive particles;

[0007] S20: Pre-fix multiple light-emitting elements to the conductive adhesive film via their pins, wherein the multiple light-emitting elements are located on the side of the conductive adhesive film away from the driving backplate;

[0008] S30: A fixed film layer is formed, wherein at least a portion of each of the light-emitting elements is covered by the fixed film layer, and the fixed film layer at least covers the surface of the plurality of light-emitting elements away from the conductive adhesive film;

[0009] S40: Pressurize the fixed film layer and heat the conductive adhesive film. The conductive adhesive film deforms, and the conductive particles in the conductive adhesive film electrically connect the light-emitting element to the driving backplate. When heated to the first temperature, the conductive adhesive film begins to solidify.

[0010] Preferably, in step S30: the surface of the fixed film layer on the side opposite to the drive back plate is a flat pressing surface.

[0011] Preferably, step S30 includes:

[0012] A leveling film is provided, which is placed on the side of the plurality of light-emitting elements away from the conductive adhesive film. The leveling film is heated and pressurized, and the leveling film softens and deforms. The plurality of light-emitting elements are embedded in the leveling film. When heated to a second temperature, the leveling film is cured and forms the fixed film layer.

[0013] Preferably, the first temperature is greater than or equal to the second temperature.

[0014] Preferably, the manufacturing method further includes step S50, which is after step S40: removing the fixed film layer.

[0015] Preferably, step S30 includes:

[0016] Photosensitive adhesive is spin-coated on the side of the conductive adhesive film away from the driving backplate, and the photosensitive adhesive covers the plurality of light-emitting elements. The photosensitive adhesive is then irradiated with ultraviolet light to cure it and form the fixed film layer.

[0017] Preferably, in step S30:

[0018] The photosensitive adhesive includes a first photosensitive adhesive and a second photosensitive adhesive. First, the first photosensitive adhesive is spin-coated on the side of the conductive adhesive film away from the driving backplate, and at least a portion of each light-emitting element is covered by the first photosensitive adhesive. The first photosensitive adhesive forms a first sub-film layer on the side of the conductive adhesive film away from the driving backplate. Then, the second photosensitive adhesive is spin-coated on the side of the first sub-film layer away from the conductive adhesive film, and the second photosensitive adhesive covers the plurality of light-emitting elements. The second photosensitive adhesive forms a second sub-film layer on the side of the first sub-film layer away from the conductive adhesive film. The second sub-film layer at least covers the surface of the plurality of light-emitting elements on the side away from the conductive adhesive film. The first sub-film layer and the second sub-film layer are irradiated with ultraviolet light to cure the first sub-film layer and the second sub-film layer to form the fixed film layer.

[0019] Preferably, step S30 includes: first forming a first sub-film layer on the side of the conductive adhesive film away from the driving backplate, and then forming a second sub-film layer on the side of the first sub-film layer away from the conductive adhesive film, wherein at least a portion of each light-emitting element is covered by the first sub-film layer, and the second sub-film layer at least covers the surface of the plurality of light-emitting elements on the side away from the conductive adhesive film, and the first sub-film layer and the second sub-film layer form the fixing film layer.

[0020] Preferably, in step S30: firstly, a thermosetting adhesive is spin-coated on the side of the conductive adhesive film away from the driving backplate, at least a portion of each light-emitting element is covered by the thermosetting adhesive, the thermosetting adhesive forms a first sub-film layer on the side of the conductive adhesive film away from the driving backplate, then a photosensitive adhesive is spin-coated on the side of the first sub-film layer away from the conductive adhesive film, the photosensitive adhesive covers the plurality of light-emitting elements, the photosensitive adhesive forms a second sub-film layer on the side of the first sub-film layer away from the conductive adhesive film, the second sub-film layer at least covers the surface of the plurality of light-emitting elements on the side away from the conductive adhesive film, the second sub-film layer is irradiated with ultraviolet light to cure the second sub-film layer, the first sub-film layer is heated to cure the first sub-film layer, and the cured first sub-film layer and the cured second sub-film layer form the fixed film layer.

[0021] Preferably, the transmittance of the first sub-film layer is less than the transmittance of the second sub-film layer.

[0022] In the manufacturing method of the display module provided in this application, the light-emitting elements and the driving backplate are electrically connected by conductive particles of a conductive adhesive film. Due to the inconsistent thickness of each light-emitting element, there is a height difference between the light-emitting elements fixed to the conductive adhesive film in the thickness direction of the driving backplate. This results in the surfaces of each light-emitting element facing away from the driving backplate not being on the same plane. By setting a fixing film layer, the uneven stress on each light-emitting element caused by the inconsistent thickness can be eliminated, reducing the pressure difference on each light-emitting element. This improves the conductivity yield between the light-emitting elements and the driving backplate, preventing insufficient deformation and poor conductivity of conductive particles corresponding to thinner light-emitting elements, and preventing excessive deformation of conductive particles corresponding to thicker light-emitting elements, which could damage the light-emitting elements and the driving backplate in contact with them. The manufacturing method of the display module provided in this application improves the electrical connection yield between the light-emitting elements and the driving backplate. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic flowchart of a method for manufacturing a display module according to the first embodiment of this application;

[0025] Figures 2 to 6 It corresponds Figure 1 A schematic diagram of the structural steps of the manufacturing method for the display module shown;

[0026] Figure 7 This is a schematic diagram of a fixed film layer provided in the first embodiment of this application;

[0027] Figure 8 This is a schematic diagram of another fixed film layer structure provided in the first embodiment of this application;

[0028] Figure 9 This is a schematic flowchart of a method for manufacturing a display module according to the second embodiment of this application;

[0029] Figures 10 to 13 It corresponds Figure 9 A schematic diagram of the structural steps of the manufacturing method for the display module shown;

[0030] Figure 14 This is a flowchart illustrating a method for manufacturing a display module according to the third embodiment of this application;

[0031] Figures 15 to 19 It corresponds Figure 14 The diagram shows the structural steps of the manufacturing method for the display module.

[0032] In the attached image:

[0033] 1-Driver backplane; 2-Conductive adhesive film; 21-Conductive particles; 3-Light emitting diode; 300-Pin; 31-Red miniaturized light emitting diode; 32-Green miniaturized light emitting diode; 33-Blue miniaturized light emitting diode; 4-Fixing film layer; 41-Leveling film; 411-First film layer; 412-Second film layer; 413-Third film layer; 42-Photosensitive adhesive; 43-First sub-film layer; 44-Second sub-film layer; 5-Ultra-flat plate; 6-Flat pressing plate. Detailed Implementation

[0034] The features and exemplary embodiments of various aspects of this application will now be described in detail. Numerous specific details are set forth in the following detailed description in order to provide a comprehensive understanding of this application. However, it will be apparent to those skilled in the art that this application can be implemented without some of these specific details. The following description of embodiments is merely intended to provide a better understanding of this application by illustrating examples thereof.

[0035] In related technologies, the epitaxial substrates and fabrication processes of miniaturized light-emitting diodes (LEDs) of different colors vary, and there are individual precision differences among the miniaturized LEDs during fabrication. This results in differences in the thickness (i.e., the minimum distance between the electrode and the side away from the electrode) of different miniaturized LEDs. After the miniaturized LEDs are transferred to the driving backplate in batches, due to the thickness differences, the pressure exerted on each miniaturized LED during the fixing process to the driving backplate is not equal. This leads to differences in the connection between the miniaturized LEDs and the driving backplate, making it easy for some thinner miniaturized LEDs to have poor connections with the driving backplate, while some thicker miniaturized LEDs are easily damaged due to excessive pressure during fixing. Based on the research on the above problems, this application provides a method for manufacturing a display module to achieve good fixing of LEDs to the driving backplate and improve the connection yield.

[0036] The manufacturing method of the display module provided in this application is applicable to fixing ordinary light-emitting diodes, miniaturized light-emitting diodes, etc., to a driving backplate. The miniaturized light-emitting diodes include miniaturized light-emitting diodes with flip-chip structures and miniaturized light-emitting diodes with vertical structures, etc. The driving backplate can be a driving backplate with thin-film transistors (TFTs), a driving backplate with miniaturized driving chips (micro ICs), or a driving backplate with silicone substrate, etc. This application does not make any special limitations on the type of light-emitting diode or the type of driving backplate.

[0037] To better understand this application, we will use a miniaturized light-emitting diode (LED) with a flip-chip structure as an example. In this case, the LED may include a red miniaturized LED 31, a green miniaturized LED 32, and a blue miniaturized LED 33. Due to differences in manufacturing precision and epitaxial substrates, the thicknesses of the same color and different colors of the miniaturized LEDs 31, 32, and 33 may vary. The following will be combined with... Figures 1 to 19 The method for fixing the miniaturized light-emitting diode to the driving backplane according to the embodiments of this application will be described in detail.

[0038] Please refer to Figures 1 to 8 The first embodiment of this application provides a method for manufacturing a display module. The display module includes a driving backplate 1 and a plurality of light-emitting diodes 3 mounted on the driving backplate 1, such as... Figure 1 As shown, the manufacturing method of the display module includes the following steps:

[0039] S1: A drive backplate 1 is provided, and a conductive adhesive film 2 is formed on one side surface of the drive backplate 1. The conductive adhesive film 2 has a plurality of conductive particles 21.

[0040] S2: Multiple light-emitting diodes 3 are pre-fixed to the conductive film 2 via their pins 300. The multiple light-emitting diodes 3 are located on the side of the conductive film 2 away from the driving backplate 1, such as... Figure 2 As shown;

[0041] S3: A leveling film 41 is provided. The leveling film 41 is placed on the side of the plurality of light-emitting diodes 3 away from the conductive adhesive film 2. A flat pressing plate or air pressure film is placed on the side of the leveling film 41 away from the light-emitting diodes 3. The pressing equipment is used for heating and pressurization. Specifically, the leveling film is pressurized and heated by the flat pressing plate or air pressure film. During the heating and pressurization process, the leveling film 41 softens and deforms, and the plurality of light-emitting diodes 3 are embedded in the leveling film 41. Heating continues until a second temperature is reached, at which point the leveling film 41 is cured and forms a fixed film layer 4. At least a portion of each light-emitting diode 3 is covered by the fixed film layer 4, and the fixed film layer 4 covers at least the surface of the plurality of light-emitting diodes 3 away from the conductive adhesive film 2. The surface of the fixed film layer 4 away from the driving backplate 1 is a flat pressing surface. The flat pressing plate or air pressure film is attached to the flat pressing surface of the fixed film layer 4. Figures 3 to 4 As shown;

[0042] S4: Continue heating and pressurizing using this pressing equipment. Specifically, pressurize the fixed film layer using a flat pressing plate or air pressure membrane to heat the conductive adhesive film 2. During the heating and pressurizing process, the conductive adhesive film 2 deforms, and the light-emitting diode 3 achieves electrical connection with the driving backplate 1 through the conductive particles 21 in the conductive adhesive film 2. When heated to the first temperature, the conductive adhesive film 2 begins to cure. Figure 5 As shown.

[0043] S5: After the pressing equipment completes the pressing process, remove the flat pressing plate or air pressure film, and remove the fixing film layer 4 to obtain the required display module, such as... Figure 6 As shown.

[0044] In the above steps, the first temperature is the temperature at which the conductive adhesive film 2 begins to cure, and the second temperature is the temperature at which the leveling film 41 completes curing and forms the fixed film layer 4. The second temperature is less than the first temperature, or the second temperature is equal to the first temperature, or the second temperature is greater than the first temperature and close to the first temperature; preferably, the second temperature is less than the first temperature.

[0045] The pressure equipment can be a hard pressure equipment, such as a batch transfer equipment or a bonding equipment. The equipment is required to meet the following requirements: pressure uniformity less than or equal to 1%, and temperature reaching 98% of the curing temperature of the conductive adhesive film 2 within 3 seconds. The pressure equipment can also be a pneumatic pressure equipment, such as a nanoimprinting equipment. The equipment is required to meet the following requirements: temperature reaching 98% of the curing temperature of the conductive adhesive film 2 within 3 seconds.

[0046] The pressing equipment must meet the following requirement: the temperature must rise to the required temperature within 3 seconds. In this embodiment, the flat pressing plate is an ultra-flat plate 5, which can be a silicon wafer or ultra-flat glass with good thermal conductivity and a total thickness variation (TTV) of less than or equal to 7 μm. The temperature at which the leveling film 41 completes curing and forms the fixed film layer 4 is lower than the temperature at which the conductive adhesive film 2 begins to cure. For example, if the initial curing temperature of the conductive adhesive film 2 is 85°C, the temperature at which the leveling film 41 completes curing and forms the fixed film layer 4 is preferably less than 85°C; or, the temperature at which the leveling film 41 completes curing and forms the fixed film layer 4 is greater than and close to the initial curing temperature of the conductive adhesive film 2. For example, if the initial curing temperature of the conductive adhesive film 2 is 85°C, the temperature at which the leveling film 41 completes curing and forms the fixed film layer 4 is preferably less than 100°C (the degree of curing of the conductive adhesive film 2 is controlled by controlling the process time). The thickness of the leveling film 41 is required to be greater than the thickness of the portion of the light-emitting diode 3 excluding the leads. Under this condition, the thickness of the leveling film 41 should be as small as possible, such as less than or equal to 7 μm. The viscosity of the leveling film 41 when softened should be as low as possible, such as less than or equal to 10 Pa·s.

[0047] In the manufacturing method of the display module provided in this embodiment, the light-emitting diode 3 and the driving backplate 1 are electrically connected through the conductive particles 21 in the conductive adhesive film 2. By applying pressure to the conductive adhesive film 2, the conductive adhesive film 2 is deformed, and the conductive particles 21 are electrically connected between the light-emitting diode 3 and the driving backplate 1. After the conductive adhesive film 2 is cured by heating, the electrical connection between the light-emitting diode 3 and the driving backplate 1 can be realized. Because the heights of the LEDs 3 are inconsistent, the LEDs 3 pre-fixed to the conductive film 2 have a height difference in the thickness direction of the driving backplate 1. This causes the surfaces of the LEDs 3 facing away from the driving backplate 1 to be not on the same plane. By setting the fixing film layer 4, the uneven force on the LEDs 3 caused by the inconsistent thickness can be eliminated, reducing the pressure difference on each LED 3. This improves the conductivity yield between the LEDs 3 and the driving backplate 1, preventing insufficient deformation and poor conductivity of the conductive particles 21 corresponding to the thinner LEDs 3, and also preventing excessive deformation of the conductive particles 21 corresponding to the thicker LEDs 3, which could damage the LEDs 3 and the driving backplate 1. The manufacturing method of the display module provided in this application improves the electrical connection yield between the LEDs 3 and the driving backplate 1.

[0048] In this embodiment, the conductive film 2 can be an anisotropic conductive film (ACF), and the conductive particles 21 in the conductive film 2 are arranged in a matrix, with a density of 25000 pcs / mm². 2 -60000pcs / mm 2Preferably, the density of the conductive particles 21 is 50,000 pcs / mm². 2 The diameter of the conductive particles 21 is 2µm-3.5µm, preferably 2.2µm. The thickness of the conductive film 2 is 4µm-10µm, preferably 4µm.

[0049] In this embodiment, the light-emitting diode 3 and the driving backplate 1 are electrically connected by conductive particles 21 in the conductive adhesive film 2. Compared with the method of directly welding the light-emitting diode 3 to the pads on the driving backplate 1, the welding method requires heating the pins 300 of the light-emitting diode 3 and the pads. The temporary substrate used to transfer the light-emitting diode 3 expands due to heat, which causes the relative position of the light-emitting diode 3 on the temporary substrate to change with the expansion of the temporary substrate and the driving backplate 1. This results in misalignment between the pins of the light-emitting diode 3 and the pads on the driving backplate 1, leading to poor connection. In this application, the electrical connection method using conductive particles 21 in the conductive adhesive film 2 will not cause misalignment between the pins of the light-emitting diode 3 and the connection point of the driving backplate 1 due to temperature changes. The method of electrically connecting the light-emitting diode 3 to the pads has weak adhesion after heating, which easily leads to poor welding. The electrical connection method using conductive particles 21 in the conductive adhesive film 2 has a better electrical connection effect.

[0050] In this embodiment, the fixed film layer 4 is formed by a leveling film 41, which can have two structural forms. The first structure is as follows: Figure 7 As shown, the leveling film 41 includes a first film layer 411, a second film layer 412, and a third film layer 413 located between the first film layer 411 and the second film layer 412. The third film layer 413 can soften and deform after being heated and pressurized. When heated to a second temperature, the third film layer 413 is cured, that is, the leveling film 41 can form a fixed film layer 4. A second structure is shown below. Figure 8 As shown, the leveling film 41 includes a first film layer 411 and a third film layer 413. The third film layer 413 can soften and deform after being heated and pressurized, and it solidifies when heated to a second temperature, thus forming a fixed film layer 4. Specifically, the third film layer 413 can be a hot melt adhesive or a UV-curable adhesive. The hot melt adhesive begins to solidify when heated to a certain temperature; at this point, the hot melt adhesive is a thermosetting hot melt adhesive.

[0051] The leveling film 41 is generally light yellow or pale yellow in color, which affects the light extraction efficiency and average light intensity of the light-emitting diode 3. The leveling film 41 is initially in a solid state. By heating, the third film layer 413 in the leveling film 41 is changed to an intermediate state (i.e., a molten state). At this time, after applying pressure to the leveling film 41, the leveling film 41 can soften and deform to cover at least a portion of the light-emitting diode 3 and fill the thickness difference between multiple light-emitting diodes 3. When the leveling film 41 is heated and pressurized, an ultra-flat plate 5 is provided on the side of the leveling film 41 away from the driving back plate 1, so that after the leveling film 41 is cured to form a fixed film layer 4, the surface of the fixed film layer 4 away from the driving back plate 1 forms a flat pressing surface; when heated to the second temperature, the leveling film 41 is cured and forms a fixed film layer 4, maintaining the shape of the flat pressing surface, thereby maintaining the compensation effect for the thickness difference between multiple light-emitting diodes 3, so as to provide uniform pressure to each light-emitting diode 3 during the heating and pressurization process in step S4, thereby ensuring that each light-emitting diode 3 and the driving back plate 1 achieve a good connection effect.

[0052] In the above embodiment, both the first film layer 411 and the second film layer 412 are very thin. The first film layer 411 is a layer used for contacting the light-emitting diode 3, and its thickness is less than or equal to 7 μm. The materials of the first film layer 411 and the second film layer 412 can be high-temperature resistant materials, such as polyimide (PI) or polyethylene terephthalate (PET), or high-temperature resistant perfluoroethylene propylene copolymer (FEP), meltable polytetrafluoroethylene (PFA), polytetrafluoroethylene (PTFE), or ethylene-tetrafluoroethylene copolymer (ETFE). During the heating and pressurization process, the first film layer 411 can change according to the shape of the light-emitting diode 3 it contacts, so as to cover the part of the light-emitting diode 3 except for the leads. The leads 300 of the light-emitting diode 3 are away from the leveling film 41 and remain in contact with the conductive adhesive film 2.

[0053] The ultra-flat plate 5 is required to be a silicon wafer or ultra-flat glass with good thermal conductivity and a total thickness variation of less than or equal to 7 μm. The thickness of the ultra-flat plate 5 can be 1 mm to 7 mm.

[0054] Specifically, a hard pressure device or a pneumatic pressure device can be used to pressurize the leveling film 41 to fill the gap between the light-emitting diodes 3 and form a flat pressing surface.

[0055] When the pressure-pressing equipment is a hard-pressing equipment, specifically a batch transfer equipment or bonding equipment, the pressure uniformity of the hard-pressing equipment is less than or equal to 1% to ensure better electrical connection between each LED 3 and the driving backplate 1. This prevents excessive local pressure, thus avoiding damage to the LEDs 3 and driving backplate 1 caused by excessive deformation of some conductive particles 21 in the conductive film 2. Simultaneously, it prevents excessive local pressure, thus avoiding insufficient deformation and poor conductivity of some conductive particles 21 in the conductive film 2. When using a hard-pressing equipment, the temperature must reach 98% of the curing temperature of the conductive film 2 within 3 seconds to improve the conductivity of the conductive film 2.

[0056] When the pressure equipment is a pneumatic pressure equipment, such as a nanoimprinting equipment, the heating speed of the conductive adhesive film 2 must be fast, and the temperature must reach 98% of the curing temperature of the conductive adhesive film 2 within 3 seconds, so as to make the conductive adhesive film 2 more conductive.

[0057] When using a pneumatic pressure device, a pneumatic membrane needs to be placed on the side of the leveling membrane 41 that is away from the drive back plate 1.

[0058] Specifically, the pressure film material can be perfluoroethylene-propylene copolymer, fusible polytetrafluoroethylene, polytetrafluoroethylene, or ethylene-tetrafluoroethylene copolymer, with a thickness of 25µm to 200µm. In step S4, the pressure equipment is used to continue heating and pressurizing, so that each LED 3 is subjected to uniform force. After pressurization, the leads 300 of the LED 3 are completely embedded in the conductive adhesive film 2 and come into contact with the conductive particles 21 in the conductive adhesive film 2. One end of the conductive particles 21 contacts the leads 300 of the LED 3, and the other end of the conductive particles 21 contacts the conductive connection point of the driving backplate 1, thereby realizing the electrical connection between the LED 3 and the driving backplate 1. In step S4, the conductive adhesive film 2 is heated from the side of the driving backplate 1 away from the LED 3. When the temperature reaches the first temperature, the conductive adhesive film 2 is cured.

[0059] In the manufacturing method of the display module provided in the first embodiment of this application, the leveling film 41 is cured at a second temperature to form a fixed film layer 4, and the conductive adhesive film 2 begins to cure at a first temperature. The second temperature is lower than the first temperature, that is, the completion curing temperature of the leveling film 41 is lower than the starting curing temperature of the conductive adhesive film 2. Therefore, when the leveling film 41 is cured, the conductive adhesive film 2 has not yet begun to cure, thus not affecting the conductivity of the conductive adhesive film 2. If the conductive adhesive film 2 cures prematurely, greater pressure is required to achieve the electrical connection between the light-emitting diode 3 and the driving backplate 1. However, excessive pressure will damage the light-emitting diode 3 and the driving backplate 1. In this application, the conductive adhesive film 2 does not begin to cure after the leveling film 41 is cured, so a smaller pressure is needed to achieve the electrical connection between the driving backplate 1 and the light-emitting diode 3, which helps to improve the fixing yield between the driving backplate 1 and the light-emitting diode 3 and reduce damage to the driving backplate 1 and the light-emitting diode 3. Alternatively, the leveling film 41 can also be selected that meets the following condition: when the leveling film 41 is cured, a portion of the conductive adhesive film 2 is cured. In this case, it is necessary to ensure that the curing degree of the conductive adhesive film 2 will not damage the driving backplate 1 or the light-emitting diode 3 during the electrical connection process.

[0060] In this embodiment, after step S4, the process further includes removing the fixed film layer 4.

[0061] When the fixing film layer 4 has color, it needs to be removed to prevent it from affecting the light emission effect of the light-emitting diode 3. The fixing film layer 4 is formed by the leveling film 41, which is generally light yellow. In this case, the fixing film layer 4 can be removed by peeling to prevent it from affecting the light emission effect of the light-emitting diode 3.

[0062] Please refer to Figures 9 to 13 The second embodiment of this application provides another method for manufacturing a display module. The differences between the second embodiment and the first embodiment will be described below, while the similarities will not be described in detail.

[0063] Unlike the first embodiment, in the second embodiment, the fixed film layer 4 is formed by photosensitive adhesive 42, which can be cured under ultraviolet light to form the fixed film layer 4.

[0064] Please see Figure 9 The manufacturing method of the display module provided in this embodiment includes the following steps:

[0065] S1: A drive backplate 1 is provided, and a conductive adhesive film 2 is formed on one side surface of the drive backplate 1. The conductive adhesive film 2 has a plurality of conductive particles 21.

[0066] S2: Multiple light-emitting diodes 3 are pre-fixed to the conductive film 2 through their pins 300, and the multiple light-emitting diodes 3 are located on the side of the conductive film 2 away from the driving backplate 1;

[0067] S3: Spin-coat photosensitive adhesive 42 on the side of the conductive adhesive film 2 away from the driving backplate 1. The photosensitive adhesive 42 covers multiple light-emitting diodes 3, such as... Figure 10 As shown;

[0068] S4: Expose the photosensitive adhesive 42 to ultraviolet light to cure it and form a fixed film layer 4, such as Figure 11 As shown;

[0069] S5: Place the flat pressing plate 6 or the air pressure film on the side of the fixed film layer 4 away from the conductive adhesive film 2, and use this pressing equipment to heat and pressurize it. Specifically, pressurize the flat pressing plate 6 or the air pressure film, and heat the conductive adhesive film 2. During the heating and pressurization process, the conductive adhesive film 2 deforms, and the light-emitting diode 3 achieves electrical connection with the driving backplate 1 through the conductive particles 21 in the conductive adhesive film 2. When the temperature reaches the first temperature, the conductive adhesive film 2 begins to cure. Figure 12 As shown;

[0070] S6: After the pressing equipment completes the pressing process, remove the flat pressing plate 6 or the air pressure film to obtain the required display module, such as... Figure 13 As shown.

[0071] In this embodiment, photosensitive adhesive 42 can be applied to the side of the conductive adhesive film 2 away from the driving backplate 1 by spin coating. This involves first dispensing the adhesive and then evenly coating it to completely cover the light-emitting diode 3. The surface of the photosensitive adhesive 42 away from the driving backplate 1 is flat, forming a smooth bonding surface after curing. Since the photosensitive adhesive 42 is cured by ultraviolet light irradiation, no heating is required during the curing process, thus not affecting the state of the conductive adhesive film 2. This avoids the need for greater pressure in step S5 due to premature curing of the conductive adhesive film 2, thereby preventing damage to the driving backplate 1 or the light-emitting diode 3 during electrical connection and contributing to improved fixing yield of the driving backplate 1 and the light-emitting diode 3.

[0072] Since the aforementioned fixing film layer 4 is formed directly on the surface of the conductive adhesive film 2 facing away from the driving backplate 1 and is cured, in step S5, the fixing film layer 4 and the light-emitting diode 3 are simultaneously pressed against the conductive adhesive film 2. Because the fixing film layer 4 is non-conductive, it will not affect the connection between the light-emitting diode 3 and the driving backplate 1. In this embodiment, a colorless and transparent photosensitive adhesive 42 is used to form the colorless and transparent fixing film layer 4, avoiding any impact on the light-emitting state of the light-emitting diode 3, and it does not need to be removed in step S6.

[0073] In step S5, a hard pressure device or a pneumatic pressure device is used to pressurize the flat bonding surface of the fixed film layer 4. When a hard pressure device is used, a flat bonding plate 6 can be provided on the side of the fixed film layer 4 away from the drive back plate 1, so that the pressure on the flat bonding surface can be more uniform. The flat bonding plate 6 can be the same as the ultra-flat plate 5 in the first embodiment, or the flat bonding plate 6 can be a silicon plate. The flat bonding plate 6 includes a substrate and an array of protrusions connected to the substrate. The array of protrusions cooperates with the flat bonding surface of the fixed film layer 4, so that the pressure can be maximized during the pressurization process.

[0074] Please refer to Figures 14 to 19 The third embodiment of this application provides another method for manufacturing a display module. The differences between the third embodiment and the second embodiment will be described below, while the similarities will not be described in detail.

[0075] Unlike the second embodiment, in the third embodiment, the fixed film layer 4 includes a first sub-film layer 43 and a second sub-film layer 44 stacked along the thickness direction of the drive back plate 1.

[0076] Please see Figure 14 The manufacturing method of the display module provided in this embodiment includes the following steps:

[0077] S1: A drive backplate 1 is provided, and a conductive adhesive film 2 is formed on one side surface of the drive backplate 1. The conductive adhesive film 2 has a plurality of conductive particles 21.

[0078] S2: Multiple light-emitting diodes 3 are pre-fixed to the conductive film 2 through their pins 300, and the multiple light-emitting diodes 3 are located on the side of the conductive film 2 away from the driving backplate 1;

[0079] S3: A first photosensitive adhesive is spin-coated on the side of the conductive adhesive film 2 away from the driving backplate 1. At least a portion of each light-emitting diode 3 is covered by the first photosensitive adhesive, while the surface of each light-emitting diode 3 on the side away from the conductive adhesive film is not covered by the first photosensitive adhesive. The first photosensitive adhesive forms a first sub-film layer 43 on the side of the conductive adhesive film 2 away from the driving backplate 1. Figure 15 As shown;

[0080] S4: A second photosensitive adhesive is spin-coated onto the side of the first sub-film layer 43 away from the driving backplate 1. The second photosensitive adhesive covers multiple light-emitting diodes 3. The second photosensitive adhesive forms a second sub-film layer 44 on the side of the first sub-film layer 43 away from the driving backplate 1. The second sub-film layer 44 at least covers the surface of the multiple light-emitting diodes 3 away from the conductive adhesive film 2. Figure 16 As shown;

[0081] S5: The first sub-film layer 43 and the second sub-film layer 44 are irradiated with ultraviolet light to cure them and form a fixed film layer 4. Figure 17 As shown;

[0082] S6: Place the flat pressing plate 6 or the air pressure film on the side of the fixed film layer 4 away from the conductive adhesive film 2, and use this pressing equipment for heating and pressurization. Specifically, the flat pressing plate 6 or the air pressure film pressurizes the fixed film layer 4 and heats the conductive adhesive film 2. During the heating and pressurization process, the conductive adhesive film 2 deforms, and the light-emitting diode 3 achieves electrical connection with the driving backplate 1 through the conductive particles 21 in the conductive adhesive film 2. When the temperature reaches the first temperature, the conductive adhesive film 2 begins to cure. Figure 18 As shown;

[0083] S7: After the pressing equipment completes the pressing process, remove the flat pressing plate 6 or the air pressure film to obtain the required display module, such as... Figure 19 As shown.

[0084] In this embodiment, the transmittance of the first sub-film layer 43 is less than that of the second sub-film layer 44, that is, the transmittance of the first photosensitive adhesive is less than that of the second photosensitive adhesive, so as to prevent light emission crosstalk between multiple light-emitting diodes 3 and improve the light emission effect.

[0085] The first photosensitive adhesive is a gray adhesive that can be cured directly by ultraviolet light irradiation without heating, and it has a certain effect in preventing light crosstalk. The second photosensitive adhesive is a transparent photosensitive adhesive. Both the first and second photosensitive adhesives can be cured under ultraviolet light irradiation.

[0086] In this embodiment, the first photosensitive adhesive can be applied to the side of the conductive adhesive film 2 away from the driving backplate 1 by spin coating, i.e., first dispensing the adhesive and then spreading it evenly, so that the light-emitting diode 3 is partially covered by the first photosensitive adhesive. The surface of the first photosensitive adhesive away from the driving backplate 1 is a flat surface. The partial coverage of the light-emitting diode 3 by the first photosensitive adhesive includes the following two cases: First case, the flat surface of the first photosensitive adhesive away from the driving backplate 1 is flush with the surface of the light-emitting diode 3 away from the driving backplate 1, i.e., the surface of the light-emitting diode 3 away from the driving backplate 1 is not covered by the first photosensitive adhesive; Second case, the surface of the light-emitting diode 3 away from the driving backplate 1 protrudes beyond the flat surface of the first photosensitive adhesive away from the driving backplate 1, i.e., the portion of the light-emitting diode 3 protruding beyond the flat surface of the first photosensitive adhesive away from the driving backplate 1 is not covered by the first photosensitive adhesive.

[0087] In the above embodiment, the first photosensitive adhesive is gray in color and exposes at least one end of the light-emitting diode 3 away from the driving backplate 1, thereby preventing crosstalk between multiple light-emitting diodes 3, improving the color gamut of the light emitted by the display module, and not affecting the light emission effect of each light-emitting diode 3.

[0088] The second sub-film layer 44, formed by the second photosensitive adhesive, completely covers the surface of the light-emitting diode 3 facing away from the driving backplate 1. The surface of the second sub-film layer 44 facing away from the driving backplate 1 forms a flat bonding surface. This facilitates uniform stress on each light-emitting diode 3 during step S6, reducing stress differences and improving the conductivity yield between each light-emitting diode 3 and the driving backplate 1. The second photosensitive adhesive is colorless and transparent to prevent any impact on the emitted light color of the light-emitting diode 3.

[0089] Since the photosensitive adhesive is cured by ultraviolet light irradiation, no heating is required during the curing process, which will not affect the state of the conductive adhesive film 2. This avoids the need for greater pressure in step S6 due to the premature curing of the conductive adhesive film 2, thereby avoiding damage to the drive backplate 1 or the light-emitting diode 3 during the electrical connection process. This helps to improve the fixing yield of the drive backplate 1 and the light-emitting diode 3.

[0090] Since the aforementioned fixed film layer 4 is directly formed on the surface of the conductive adhesive film 2 facing away from the driving backplate 1 and is cured, in step S6, the aforementioned fixed film layer 4 will be squeezed synchronously with the light-emitting diode 3 to compress the conductive adhesive film 2. Since the aforementioned fixed film layer 4 is not conductive, it will not affect the electrical connection between the light-emitting diode 3 and the driving backplate 1.

[0091] In step S6, a hard pressure device or a pneumatic pressure device is used to pressurize the flat bonding surface of the fixed film layer 4. When a hard pressure device is used, a flat bonding plate 6 can be provided on the side of the fixed film layer 4 away from the drive back plate 1, so that the pressure on the flat bonding surface can be more uniform. The flat bonding plate 6 can be the same as the ultra-flat plate 5 in the first embodiment, or the flat bonding plate 6 can be a silicon plate. The flat bonding plate 6 includes a substrate and an array of protrusions connected to the substrate. The array of protrusions cooperates with the flat bonding surface of the fixed film layer 4, so that the pressure can be maximized during the pressurization process.

[0092] In this embodiment, the first photosensitive adhesive forming the first sub-film layer 43 can also be replaced by other adhesives that can be cured by temperature control. The temperature at which the first sub-film layer 43 completes curing is lower than the temperature at which the conductive adhesive film 2 begins curing. For example, if the temperature at which the conductive adhesive film 2 begins curing is 85°C, the temperature at which the first sub-film layer 43 completes curing is less than 85°C. This design avoids premature curing of the conductive adhesive film 2, which would require greater pressure in step S6, thereby preventing damage to the drive backplane 1 or the light-emitting diode 3 during the electrical connection process, thus contributing to the improvement of the fixing yield of the drive backplane 1 and the light-emitting diode 3. Alternatively, the temperature at which the first sub-film layer 43 completes curing is greater than and close to the temperature at which the conductive adhesive film 2 begins curing. For example, if the initial curing temperature of the conductive adhesive film 2 is 85°C, the temperature at which the first sub-film layer 43 completes curing is required not to exceed 90°C (the degree of curing of the conductive adhesive film 2 is controlled by controlling the process time).

[0093] Specifically, the adhesive material forming the first sub-film layer 43 can be a thermosetting adhesive, and the temperature at which the thermosetting adhesive completes its curing is lower than the temperature at which the conductive adhesive film 2 begins to cure. The light transmittance of the first sub-film layer 43 is lower than that of the second sub-film layer 44. Specifically, the first sub-film layer 43 can be formed of a black or gray thermosetting adhesive. For example, the first sub-film layer 43 can be made of BM (Black Matrix) adhesive, which is a black, opaque thermosetting adhesive. The second sub-film layer 44 is formed of a colorless and transparent second photosensitive adhesive.

[0094] When the first sub-film layer 43 is formed by thermosetting adhesive, steps S3, S4 and S5 in the third embodiment can be replaced by the following steps: First, thermosetting adhesive is spin-coated on the side of the conductive adhesive film 2 away from the driving backplate 1, and at least a portion of each light-emitting diode 3 is covered by thermosetting adhesive. The thermosetting adhesive forms the first sub-film layer 43 on the side of the conductive adhesive film 2 away from the driving backplate 1. Then, a second photosensitive adhesive is spin-coated on the side of the first sub-film layer 43 away from the conductive adhesive film 2. The second photosensitive adhesive covers multiple light-emitting diodes 3. The second photosensitive adhesive forms a second sub-film layer 44 on the side of the first sub-film layer 43 away from the conductive adhesive film 2. The second sub-film layer 44 at least covers the surface of multiple light-emitting diodes 3 on the side away from the conductive adhesive film 2. The second sub-film layer 44 is irradiated with ultraviolet light to cure the second sub-film layer 44. The first sub-film layer 43 is heated to cure the first sub-film layer 43. The cured first sub-film layer 43 and the cured second sub-film layer 44 form a fixed film layer 4.

[0095] The embodiments described above are not exhaustive and do not limit the invention to specific examples. Clearly, many modifications and variations can be made based on the above description. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to effectively utilize this application and its modifications. This application is limited only by the claims and their full scope and equivalents.

Claims

1. A method for manufacturing a display module, characterized in that, The display module includes a driving backplate and multiple light-emitting elements, and the manufacturing method includes the following steps: S10: Provide a drive backplate, wherein a conductive adhesive film is formed on one side surface of the drive backplate, and the conductive adhesive film has a plurality of conductive particles; S20: Pre-fix multiple light-emitting elements to the conductive adhesive film via their pins, wherein the multiple light-emitting elements are located on the side of the conductive adhesive film away from the driving backplate; S30: A fixed film layer is formed, at least a portion of each of the light-emitting elements is covered by the fixed film layer, and the fixed film layer covers at least the surface of the plurality of light-emitting elements away from the conductive adhesive film, and the surface of the fixed film layer away from the driving back plate is a flat pressing surface; S40: Pressurize the fixed film layer and heat the conductive adhesive film. The conductive adhesive film deforms, and the conductive particles in the conductive adhesive film electrically connect the light-emitting element to the driving backplate. When heated to the first temperature, the conductive adhesive film begins to solidify.

2. The manufacturing method according to claim 1, characterized in that, Step S30 includes: A leveling film is provided, which is placed on the side of the plurality of light-emitting elements away from the conductive adhesive film. The leveling film is heated and pressurized, and the leveling film softens and deforms. The plurality of light-emitting elements are embedded in the leveling film. When heated to a second temperature, the leveling film is cured and forms the fixed film layer.

3. The manufacturing method according to claim 2, characterized in that, The first temperature is greater than or equal to the second temperature.

4. The manufacturing method according to claim 2, characterized in that, The manufacturing method further includes step S50, which follows step S40: removing the fixed film layer.

5. The manufacturing method according to claim 1, characterized in that, Step S30 includes: Photosensitive adhesive is spin-coated on the side of the conductive adhesive film away from the driving backplate, and the photosensitive adhesive covers the plurality of light-emitting elements. The photosensitive adhesive is then irradiated with ultraviolet light to cure it and form the fixed film layer.

6. The manufacturing method according to claim 5, characterized in that, In step S30: The photosensitive adhesive includes a first photosensitive adhesive and a second photosensitive adhesive. First, the first photosensitive adhesive is spin-coated on the side of the conductive adhesive film away from the driving backplate, and at least a portion of each light-emitting element is covered by the first photosensitive adhesive. The first photosensitive adhesive forms a first sub-film layer on the side of the conductive adhesive film away from the driving backplate. Then, the second photosensitive adhesive is spin-coated on the side of the first sub-film layer away from the conductive adhesive film, and the second photosensitive adhesive covers the plurality of light-emitting elements. The second photosensitive adhesive forms a second sub-film layer on the side of the first sub-film layer away from the conductive adhesive film. The second sub-film layer at least covers the surface of the plurality of light-emitting elements on the side away from the conductive adhesive film. The first sub-film layer and the second sub-film layer are irradiated with ultraviolet light to cure the first sub-film layer and the second sub-film layer to form the fixed film layer.

7. The manufacturing method according to claim 1, characterized in that, Step S30 includes: first forming a first sub-film layer on the side of the conductive adhesive film away from the driving backplate, and then forming a second sub-film layer on the side of the first sub-film layer away from the conductive adhesive film, wherein at least a portion of each light-emitting element is covered by the first sub-film layer, and the second sub-film layer at least covers the surface of the plurality of light-emitting elements on the side away from the conductive adhesive film, and the first sub-film layer and the second sub-film layer form the fixing film layer.

8. The manufacturing method according to claim 7, characterized in that, In step S30: First, a thermosetting adhesive is spin-coated onto the conductive adhesive film on the side away from the driving backplate, at least a portion of each light-emitting element is covered by the thermosetting adhesive, and the thermosetting adhesive forms a first sub-film layer on the side of the conductive adhesive film away from the driving backplate. Then, a photosensitive adhesive is spin-coated onto the side of the first sub-film layer away from the conductive adhesive film, and the photosensitive adhesive covers the plurality of light-emitting elements. The photosensitive adhesive forms a second sub-film layer on the side of the first sub-film layer away from the conductive adhesive film, and the second sub-film layer at least covers the surface of the plurality of light-emitting elements on the side away from the conductive adhesive film. The second sub-film layer is irradiated with ultraviolet light to cure the second sub-film layer. The first sub-film layer is heated to cure the first sub-film layer. The cured first sub-film layer and the cured second sub-film layer form the fixed film layer.

9. The manufacturing method according to claim 6 or 7, characterized in that, The transmittance of the first sub-film layer is less than that of the second sub-film layer.

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