Manufacturing method of display module, display module and repair method

Abstract

The application discloses a kind of display module manufacturing method, comprising: step one, provide a substrate, the front surface of the substrate is equipped with several light emitting chips;Step two, spray thin film protective material on the substrate, solidify the thin film protective material to form the thin film protective layer attached to the front surface of the substrate, the front surface and side of the light emitting chip;Step three, provide a protective film piece, the bottom layer of the protective film piece is soft glue layer, the protective film piece is pasted to the front surface of the substrate by soft glue layer, and the soft glue layer is filled in the gap between adjacent light emitting chips, and the soft glue layer is solidified to form filling layer.The application also discloses corresponding display module and display module repair method.Compared with prior art, the application is convenient to package, and the production efficiency is high, the packaged display module is easy to repair, and the surface ink consistency of the repaired display module is good.

Description

Technical Field

[0001] This invention relates to the manufacture of a display module, and more particularly to the packaging and repair of display modules. Background Technology

[0002] Mini / Micro LED displays are a new type of small-pitch high-definition display technology that is currently being promoted and widely used, especially in large-screen high-definition indoor displays, such as command centers, conference centers, security monitoring, and home large-screen TVs. Mini / Micro LED displays are made up of multiple Mini / Micro LED display modules spliced ​​together.

[0003] Mini / Micro LED display modules fix RGB Mini / Micro LED chips (hereinafter referred to as LED chips) to one surface of a circuit board, and control the display through a driver IC on the other surface. After the LED chips are fixed, an encapsulation layer is usually formed on their surface. The encapsulation layer can prevent the LED chips from being directly impacted by external forces, and can also prevent short circuit damage caused by water and oxygen contact, thus providing protection. The encapsulation layer mainly adds an epoxy resin-based encapsulation material to the surface of the LED chip array, and forms a flat shape through a lamination process. The disadvantage of this encapsulation protection method is that the encapsulation layer is a one-piece structure. When an LED chip fails, the encapsulation layer needs to be removed, the faulty LED chip replaced, and then the encapsulation material added and flattened. This inevitably affects the uniformity of the ink color on the surface of the encapsulation layer. If the encapsulation layer is completely removed, it will damage the normal LED chips and result in high repair costs.

[0004] Therefore, there is an urgent need for a method for manufacturing display modules, display modules, and rework methods that can solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for manufacturing a display module and a display module that is easy to repair and has good uniformity of ink color on the surface of the repaired display module.

[0006] To achieve the above objectives, the present invention discloses a method for manufacturing a display module, comprising: Step 1, providing a substrate, wherein a plurality of light-emitting chips are mounted on the front side of the substrate; Step 2, spraying a thin-film protective material onto the substrate, and curing the thin-film protective material to form a thin-film protective layer attached to the front side of the substrate, the front side of the light-emitting chips, and the side surface; Step 3, providing a protective film, wherein the bottom layer of the protective film is a soft adhesive layer, attaching the protective film to the front side of the substrate through the soft adhesive layer, and filling the gaps between adjacent light-emitting chips with the soft adhesive layer, and curing the soft adhesive layer to form a filling layer.

[0007] Preferably, the substrate includes a PCB substrate or a glass substrate.

[0008] Preferably, the film-like protective material comprises an adhesive material and a diluent uniformly mixed together.

[0009] Specifically, the ratio of the adhesive material to the diluent is 1:3 to 3:5.

[0010] Specifically, the adhesive material is one or more of epoxy resin, silicone resin, acrylic resin, and polyurethane.

[0011] Specifically, the thin-film protective material also contains silicon dioxide, which can make the spraying effect more uniform when the thin-film protective material is sprayed.

[0012] Preferably, the thickness of the thin-film protective material is 15~40μm, with 20μm being more preferred.

[0013] Preferably, the soft adhesive layer is an OCA soft adhesive layer, and the thickness of the soft adhesive layer is greater than or equal to 100 μm.

[0014] Specifically, the thickness of the soft adhesive layer is 150 μm, but this thickness can be appropriately reduced or increased depending on the size of the light-emitting chip.

[0015] Preferably, between step two and step three, there is an additional step: aging treatment of the substrate and the light-emitting chip mounted thereon.

[0016] Preferably, the protective film further includes a black ink layer formed on the soft adhesive layer and a transparent layer formed on the black ink layer.

[0017] Preferably, the transparent layer is PET.

[0018] Preferably, the protective film further includes an AG, AR, or AF layer formed on the transparent layer.

[0019] Preferably, the soft adhesive layer contains a diffusion powder material, which helps to convert the dot-shaped light spot of the light-emitting chip into a planar light spot.

[0020] Preferably, the diffusion powder material is silicon dioxide.

[0021] The present invention also discloses a display module, including a substrate, a plurality of light-emitting chips mounted on the front side of the substrate, a thin film protective layer covering the front side of the substrate and the front and side sides of the light-emitting chips, and a protective film pasted on the front side of the substrate and the light-emitting chips. The bottom layer of the protective film is a soft adhesive layer, which fills the gap between adjacent light-emitting chips and is cured to form a filling layer.

[0022] Preferably, the protective film further includes a black ink layer formed on the soft adhesive layer and a transparent layer formed on the black ink layer.

[0023] Preferably, the transparent layer is PET.

[0024] Preferably, the protective film further includes a functional layer formed on the transparent layer, wherein the functional layer is an AG, AR, or AF layer.

[0025] Preferably, the soft adhesive layer contains a diffusion powder material, which helps to convert the dot-shaped light spot of the light-emitting chip into a planar light spot. Specifically, the diffusion powder material is silicon dioxide.

[0026] Preferably, the display module is manufactured using the above-described method for manufacturing a display module.

[0027] This invention also discloses a method for repairing a display module, used to repair the display module as described above. The method includes: determining the fault location of the faulty light-emitting chip; removing the protective film; breaking the thin film protective layer at the fault location and removing the faulty light-emitting chip; reinstalling the light-emitting chip at the fault location; spraying a thin film protective material onto the fault location and curing it to repair the thin film protective layer; re-attaching a new protective film to the front side of the substrate and filling the gap between adjacent light-emitting chips with a soft adhesive layer, and curing the soft adhesive layer to form a filling layer.

[0028] Compared with existing technologies, the display module of this invention uses a protective film with a soft adhesive layer as the bottom layer, which is attached to the front of the substrate to fill the gaps between the light-emitting chips and form a protective structure on the front of the substrate. This eliminates the need for encapsulating adhesive, making encapsulation convenient and increasing production efficiency. When repairing the display module, there is no need to break the encapsulation layer; simply peel off the protective film. No encapsulation layer needs to be filled during repair, ensuring that the surface of the repaired display module remains a uniform thin-film protective layer with consistent ink color. Furthermore, this invention fully covers the front of the light-emitting chips and the substrate with a thin-film protective layer, forming a protective layer on the surface of the light-emitting chips. The cured thin-film protective layer has strong sealing and thermal conductivity, preventing the light-emitting chips from directly contacting water and oxygen in the air. If the LED display module needs rework, the thin-film protective layer protects the light-emitting chips from damage or even detachment when the film is peeled off. The damaged light-emitting chips can then be repaired, and a new film can be reattached afterward, making repair convenient and preventing impact on other light-emitting chips. Attached Figure Description

[0029] Figure 1 This is a flowchart of the manufacturing method of the display module of the present invention.

[0030] Figure 2This is a schematic diagram illustrating the manufacturing process of the display module of the present invention.

[0031] Figure 3a This is a structural diagram of the protective film in a preferred embodiment of the present invention.

[0032] Figure 3b This is a structural diagram of the protective film in another embodiment of the present invention.

[0033] Figure 4 This is a structural diagram of the display module of the present invention.

[0034] Figure 5 This is a flowchart of the display module rework method of the present invention. Detailed Implementation

[0035] To illustrate the technical content, structural features, objectives, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0036] refer to Figure 1 and Figure 2 The present invention discloses a method for manufacturing a display module, including steps S11 to S16.

[0037] Step S11: A substrate 11 is provided, and a plurality of light-emitting chips 12 are mounted on the front side of the substrate 11. In this embodiment, the light-emitting chips 12 are LEDs. A driver IC is also mounted on the back side of the substrate 11 to drive the light-emitting chips 12 on the front side of the substrate 11. The substrate can be a PCB substrate, a glass substrate, etc.

[0038] In this embodiment, the light-emitting chip 12 is transferred to the front side of the substrate 11 using a Pick & Place process or a mass transfer process, and is fixed to the pads on the front side by reflow soldering or laser soldering; the driver IC is fixed to the back side of the substrate 11 using an SMT process.

[0039] Step S12: Spray a thin film protective material onto the substrate 11, wherein the thin film protective material covers the front side of the substrate 11, the front side and the side of the light-emitting chip 12, so as to protect the front side of the substrate 11 and the light-emitting chip 12 thereon.

[0040] The thin-film protective material 13 comprises a uniformly mixed adhesive material and a thinner. Specifically, the ratio of the adhesive material to the thinner is 1:3 to 3:5. The thinner ensures that the adhesive material has sufficient flowability in the nozzle. During the spraying of the thin-film protective material through the nozzle (from the nozzle exiting to reaching the front of the light-emitting chip 12 and the substrate 11), the thinner evaporates in the air. Finally, when the adhesive material is sprayed onto the surface of the light-emitting chip 12, the flowability of the adhesive material is greatly reduced, allowing it to adhere to the surface of the light-emitting chip 12 and form a thin film. Figure 2 The shape of the protective layer formed by spraying the thin film protective material 13 in step S12.

[0041] The thickness of the sprayed thin-film protective material 13 is controlled by adjusting the distance between the nozzle and the substrate 11 and the feeding pressure during spraying. In this embodiment, the distance between the nozzle and the substrate 11 ranges from 1 to 5 cm, and the feeding pressure ranges from 2 to 5 atm. In this embodiment, the thickness of the sprayed thin-film protective material 13 is 15 to 40 μm, with 20 μm being preferred.

[0042] The adhesive material is one or more of epoxy resin, silicone resin, acrylic resin, and polyurethane.

[0043] Preferably, the thin-film protective material 13 also contains silicon dioxide, which can make the spraying effect more uniform when the thin-film protective material 13 is sprayed.

[0044] Step S13: Curing the thin film protective material 13 to form a thin film protective layer 13' attached to the front side of the substrate 11 and the surface of the light-emitting chip 12.

[0045] The function of the thin film protective layer 13' is to form a protective layer on the surface of the light-emitting chip 12. The cured thin film protective layer 13' has strong sealing and thermal conductivity, which can prevent the light-emitting chip 12 from directly contacting water and oxygen in the air. If the display module needs to be repaired, when the protective film 20 is removed, the thin film protective layer 13' can protect the light-emitting chip 12 from being damaged or even falling off as the protective film 20 is torn. Then the damaged light-emitting chip 12 is repaired and a new protective film 20 is applied.

[0046] In this embodiment, the thin-film protective material 13 is baked and heated to solidify it into a thin-film protective layer 13'. In this embodiment, the baking temperature is 100-130℃, and the baking time is 10 min to 30 min. The thin-film protective layer 13' is cured by baking and heating, which improves the adhesion between the thin-film protective layer 13' and the light-emitting chip 12 and the substrate 11.

[0047] Step S14: Provide a protective film 20, the bottom layer of which is a soft adhesive layer 21.

[0048] In this embodiment, the soft adhesive layer 21 is an OCA soft adhesive layer. Of course, other elastic adhesive materials can also be selected as the soft adhesive layer, and it is not limited to OCA soft adhesive.

[0049] refer to Figure 2The protective film 20 further includes a PET transparent layer 22 formed on the soft adhesive layer 21 and a black ink layer 23 formed on the PET transparent layer.

[0050] For the better option, refer to Figure 3a The protective film 20 further includes a functional layer 26 formed on the ink layer 23. The functional layer 26 is an AG layer, an AR layer, or an AF layer, etc. Among them, the AR (Anti-Reflection) layer is an anti-reflective film or glass, the AG (Anti-Glare) layer is an anti-glare film or glass, and the AF (Anti-Fingerprint) layer is an anti-fingerprint film or glass.

[0051] refer to Figure 3b In another embodiment, the protective film 20a includes a carbon black layer 24 formed on the soft adhesive layer 21 and a PET transparent layer 25 formed on the carbon black layer 24. Of course, other ink materials can be used to make the ink to replace the carbon black layer 24, and it is not limited to carbon black materials. Similarly, other transparent insulating materials can be used to make the transparent layer to replace the PET transparent layer 25, and it is not limited to PET materials.

[0052] Preferably, the protective film 20a further includes a functional layer 26 formed on the PET transparent layer 25. The functional layer 26 is an AG layer, an AR layer, or an AF layer, etc.

[0053] Preferably, the soft adhesive layer 21 contains a diffusion powder material, which helps to convert the dot-shaped light spot of the light-emitting chip into a planar light spot. The diffusion powder material is silicon dioxide.

[0054] Step S15: Apply the protective film 20 to the front side of the substrate 11 and fill the gap between adjacent light-emitting chips 12 with the soft adhesive layer 21.

[0055] The thickness of the soft adhesive layer 21 is greater than or equal to 100 μm. Specifically, the thickness of the soft adhesive layer 21 is 150 μm, but this thickness can be appropriately reduced or increased depending on the size of the light-emitting chip 12.

[0056] Step S16: Curing the soft adhesive layer 21 to form a filler layer 21'.

[0057] In this embodiment, the step of curing the soft adhesive layer 21 includes: baking the soft adhesive layer 21 at a temperature of 70~80℃ for 3~5 minutes, followed by UV curing. After curing, the adhesion between the soft adhesive layer 21 and the thin film protective layer 13' is improved.

[0058] It should be noted that the bonding force between the thin film protective layer 13' and the light-emitting chip 12 and the substrate 11 is greater than the bonding force between the thin film protective layer 13' and the soft adhesive layer 21. Thus, when the display module needs to be repaired and the protective film 20 is removed, the contact surface between the soft adhesive layer 21 and the thin film protective layer 13' is a separation interface, and the thin film protective layer 13' still adheres to the surface of the light-emitting chip 12 and the substrate 11.

[0059] Preferably, between step S13 and step S15, an aging process is further included: aging the substrate 11 and the light-emitting chip 12 mounted thereon.

[0060] In this embodiment, the substrate 11 is powered on to light up the light-emitting chip 12 under an ambient temperature range of 45~55℃ (preferably 50℃) for aging treatment. The temperature on the front side of the substrate 11 needs to reach 70℃, and the aging process lasts for 48 hours.

[0061] refer to Figure 4 The present invention also discloses a display module 100, which is manufactured by the above-described display module manufacturing method. It includes a substrate 11, a plurality of light-emitting chips 12 mounted on the front side of the substrate 11, a thin film protective layer 13' covering the front side of the substrate 11 and the front and side sides of the light-emitting chips 12, and a protective film 20 pasted on the front side of the substrate 11 and the light-emitting chips 12. The bottom layer of the protective film 20 is a soft adhesive layer 21, which fills the gap between adjacent light-emitting chips 12 and is cured to form a filling layer 21'.

[0062] Compared with existing technologies, this invention seals and protects the surface of the light-emitting chip 12 by applying a film, which effectively improves production efficiency and facilitates rework compared to traditional pressure-press packaging. Furthermore, this invention uses a spray coating method to form a thin protective layer 13' on the surfaces of the substrate 11 and the light-emitting chip 12, improving the sealing performance of the film application method. Simultaneously, when the display module needs to have the protective film removed, it effectively protects the light-emitting chip, preventing damage or detachment during film removal, greatly improving production operability and reducing material waste.

[0063] refer to Figure 5 The present invention also discloses a method for repairing a display module, for repairing the display module 100 as described above, the method comprising steps S21 to S27.

[0064] Step S21: Determine the fault location of the faulty light-emitting chip 12.

[0065] Step S22: Remove the protective film 20. At this point, the thin film protective layer 13' is intact.

[0066] Step S23: Break open the thin film protective layer 13' at the fault location and remove the faulty light-emitting chip 12. In this embodiment, the thin film protective layer 13' at the fault location can be cut directly, or a laser can be used to remove part of the material of the thin film protective layer 13' along the boundary line of the fault location to expose the pads of the faulty light-emitting chip 12. The pads are heated to melt the solder, and the faulty light-emitting chip 12 is removed after melting.

[0067] Step S24: Reinstall the light-emitting chip 12 at the fault location. In this embodiment, the solder is repaired according to the solder left on the pad or excess solder is removed to make the amount of solder on the pad meet the preset range, and then a qualified light-emitting chip 12 is installed at the original pad position.

[0068] Step S25: Spray a thin film protective material 13 onto the fault location and cure it to repair the thin film protective layer 13'.

[0069] Step S26: A new protective film 20 is reattached to the front side of the substrate 11, and the soft adhesive layer 21 is filled in the gap between adjacent light-emitting chips 12.

[0070] Step S27: Curing the soft adhesive layer 21 to form a filler layer 21'.

[0071] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for manufacturing a display module, characterized in that: include: Step 1: Provide a substrate, on the front side of which are mounted a plurality of light-emitting chips; Step 2: Spray a thin film protective material onto the substrate and cure the thin film protective material to form a thin film protective layer attached to the front side of the substrate, the front side of the light-emitting chip, and the side surface. The thin film protective material includes an adhesive material. Step 3: Provide a protective film, the bottom layer of which is a soft adhesive layer. Attach the protective film to the front side of the substrate through the soft adhesive layer, filling the gaps between adjacent light-emitting chips with the soft adhesive layer. Then, cure the soft adhesive layer to form a filling layer. The bonding force between the thin film protective layer and the light-emitting chip and the substrate is greater than the bonding force between the thin film protective layer and the soft adhesive layer.

2. The method for manufacturing a display module as described in claim 1, characterized in that: The film-like protective material comprises an adhesive material and a diluent uniformly mixed together, wherein the ratio of the adhesive material to the diluent is 1:3 to 3:

5.

3. The method for manufacturing a display module as described in claim 2, characterized in that: The adhesive material is one or more of epoxy resin, silicone resin, acrylic resin and polyurethane, and the thin film protective material also contains silicon dioxide.

4. The method for manufacturing a display module as described in claim 1, characterized in that: The thickness of the thin film protective material sprayed is 15~40μm.

5. The method for manufacturing a display module as described in claim 1, characterized in that: The soft adhesive layer is an OCA soft adhesive layer, and the thickness of the soft adhesive layer is greater than or equal to 100 μm.

6. The method for manufacturing a display module as described in claim 1, characterized in that: Between steps two and three, there is also a step: aging the substrate and the light-emitting chip mounted thereon.

7. The method for manufacturing a display module as described in claim 1, characterized in that: The soft adhesive layer contains a diffusion powder material.

8. A display module, characterized in that: The device includes a substrate, a plurality of light-emitting chips mounted on the front side of the substrate, a thin film protective layer covering the front side of the substrate and the front and side surfaces of the light-emitting chips, and a protective film adhered to the front side of the substrate and the light-emitting chips. The bottom layer of the protective film is a soft adhesive layer, which fills the gaps between adjacent light-emitting chips and is cured to form a filling layer. The thin film protective layer is formed by spraying and curing a thin film-like protective material, which includes an adhesive material. The bonding force between the thin film protective layer and the light-emitting chips and the substrate is greater than the bonding force between the thin film protective layer and the soft adhesive layer.

9. The display module as described in claim 8, characterized in that: The display module is manufactured by the method of manufacturing a display module according to any one of claims 1-7.

10. A method for reworking a display module, characterized in that: For repairing the display module as described in claim 8, the repair method for the display module includes: Determine the location of the faulty LED chip; Remove the protective film; Break through the thin film protective layer at the fault location and remove the faulty light-emitting chip; Reinstall the light-emitting chip at the fault location; A thin film of protective material is sprayed onto the fault location and cured to repair the protective film layer. A new protective film is re-attached to the front side of the substrate, and the soft adhesive layer is filled into the gap between adjacent light-emitting chips. The soft adhesive layer is then cured to form a filling layer.

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