LED display module for splicing and manufacturing method thereof

Abstract

The application provides an LED display module for splicing, which comprises a substrate, a light-emitting unit and encapsulation glue, the substrate comprises an insulating base layer made of glass material, the base layer comprises a first surface and a second surface opposite to each other, and a plurality of side surfaces connecting the first surface and the second surface, the first surface is provided with a first circuit layer, the second surface is provided with a second circuit layer, at least one side surface is provided with a side circuit layer, the side circuit layer is at least partially connected with the first circuit layer and the second circuit layer, the plurality of light-emitting units are mounted on the first circuit layer, the encapsulation glue covers the first surface of the base layer and at least part of the light-emitting unit and the side circuit layer, the encapsulation glue comprises an upper surface orthogonal to the extension surface of the side surface of the substrate, and a side surface connected with the upper surface, and the upper surface and the side surface are connected through a right angle. The LED display module provided by the application does not need to be punched on the base layer, and has high structural strength. The application further provides a manufacturing method of the LED display module for splicing, and the side circuit layer can be formed on the side surface of the substrate.

Description

Technical Field

[0001] This invention relates to the field of LED displays, and more particularly to an LED display module for splicing and its manufacturing method. Background Technology

[0002] In existing LED display module packaging processes, COG (Chip On Glass) LED display modules (100' package) use glass substrates. Glass substrates offer advantages such as high flatness and low temperature-dependent volume expansion / contraction, allowing for smaller LED chip spacing in LED display modules. They are also more suitable for Mini LED die bonding, resulting in higher display resolution. LED display modules can be spliced ​​together to form large-screen displays. Existing COG LED display modules have wiring on both the front and back of the glass substrate. The front wiring is used for electrical connection to the electrodes of the Mini LEDs, while the back wiring is used for electrical connection to external circuitry. (Reference) Figure 11 There is an LED display module. In order to reduce the pixel pitch at the splicing point when splicing large-size displays, the glass substrate is provided with through holes 101 and the through holes are filled with conductive material to conduct the front and back lines. However, providing through holes 101 in the glass substrate will reduce the strength of the glass substrate. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides an LED display module for splicing, comprising a substrate, light-emitting units, and encapsulating adhesive. The substrate includes an insulating base layer made of glass. The base layer includes a first surface and a second surface opposite to each other, and a plurality of side surfaces connecting the first surface and the second surface. The first surface has a first circuit layer, the second surface has a second circuit layer, and at least one side surface has a side circuit layer. The side circuit layer at least partially connects the first circuit layer and the second circuit layer. A plurality of light-emitting units are mounted on the first circuit layer. The encapsulating adhesive covers the first surface of the base layer and at least a portion of the light-emitting units and the side circuit layers. The encapsulating adhesive includes an upper surface orthogonal to an extension surface of the side surface of the substrate, and a side surface connected to the upper surface. The upper surface and the side surface are connected at right angles.

[0004] This invention provides an LED display module with a higher-strength substrate by setting a side circuit layer to connect the first and second circuit layers, compared to the prior art which uses through holes in the substrate to connect circuits on both sides of the substrate. This avoids drilling holes in the substrate. Furthermore, by setting the side surface of the encapsulant on the splicing side of the LED display module and its adjacent upper surface to be connected at a right angle, this invention ensures that after adjacent LED display modules are spliced ​​together, only the upper surface of the encapsulant is exposed at the splicing point, avoiding rounded or beveled corners that could affect light efficiency. After splicing, only the upper surface of the encapsulant serves as the light-emitting surface of the LED display at the splicing point, ensuring consistent light emission from the LED display near and away from the splicing point, improving the optical quality of the LED display, and achieving a near-zero splicing seam effect.

[0005] Preferably, the encapsulating adhesive extends to the back side of the substrate and is flush with the surface of the back side of the substrate. This structure places the boundary between the substrate and the encapsulating adhesive at the bottom of the LED display module (i.e., the surface of the second side), thereby ensuring that the encapsulating adhesive fully covers the side circuit layer. This extends the path for moisture to enter the LED display module, increasing airtightness. Furthermore, it protects the side circuit layer and reduces wear during the assembly of LED display modules. In product design, the path for moisture to enter the LED display module can be extended by increasing the substrate thickness.

[0006] Preferably, the first circuit layer and the side circuit layer are covered with a circuit protection layer, and the encapsulating adhesive covers at least a portion of the circuit protection layer on the first circuit layer and the circuit protection layer on the side circuit layer. Since during the manufacturing process, the encapsulating adhesive may only cover a portion of the circuit protection layer on the side circuit layer, for example, only a portion of the top or side, a portion of the side may be exposed to the side of the substrate. In this case, the circuit protection layer can protect the side circuit layer and reduce damage. In one embodiment, the circuit protection layer can be an ink layer; preferably, a black ink layer.

[0007] In one embodiment, the first circuit layer, the second circuit layer, and the side circuit layer are metal layers tightly adhered to the substrate, formed by a coating process such as magnetron sputtering or thermal evaporation. This provides advantages such as good adhesion to the substrate and high stability, making the side circuit layer less prone to detachment.

[0008] This invention also provides a method for manufacturing LED display modules for splicing, comprising the following steps:

[0009] Step a: Provide a substrate, the substrate including an insulating base layer made of glass, a first circuit layer disposed on a first surface of the base layer, and a second circuit layer disposed on a second surface of the base layer opposite to the first surface, the first circuit layer having a plurality of pads corresponding to the electrodes of the light-emitting unit; wherein, the process edge at the edge where the side circuit layer needs to be disposed on the side of the substrate needs to be cut off to expose the side of the base layer and form the side circuit layer on the side of the base layer, the side circuit layer enabling at least a portion of the circuit between the first circuit layer and the second circuit layer to be conductive;

[0010] Step b: Provide light-emitting units on the plurality of pads on the first circuit layer;

[0011] Step c: A carrier plate is disposed on the side of the missing process edge of the substrate; a gap exists between the side of the carrier plate and the side of the substrate;

[0012] Step d: Provide a mold and a semi-solid encapsulating film. Place the mold on the substrate and the carrier plate, so that at least a part of the mold abuts against the carrier plate. Set the semi-solid encapsulating film in the mold and perform vacuum hot pressing, so that the semi-solid encapsulating film melts and covers the first side of the substrate, the light-emitting unit and at least a part of the carrier plate to form an encapsulating adhesive. The upper surface of the encapsulating adhesive is orthogonal to the extension surface of the side of the substrate. After curing, a cured encapsulating adhesive is obtained.

[0013] Step e: Using a cutting tool, cut off the carrier plate, the encapsulating adhesive attached to the carrier plate, and the excess process edge along the gap between the side of the substrate and the carrier plate, parallel to the side of the substrate, to obtain the LED display module.

[0014] Preferably, in step d, the encapsulating adhesive at least partially or completely fills the gap between the side of the carrier board and the side circuit layer.

[0015] Preferably, in step a, after setting the first circuit layer, the second circuit layer and the side circuit layer, the method further includes setting a circuit protection layer on the first circuit layer and the side circuit.

[0016] Preferably, in step b, the bottom of the carrier plate is connected to the second surface of the base layer by tape.

[0017] The present invention also provides an LED display screen, comprising LED display modules spliced ​​together as described above. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A front view of an LED display module for splicing, provided as an embodiment of this application;

[0020] Figure 2a For an example Figure 1 A schematic diagram of the AA section;

[0021] Figure 2b This is a structural schematic diagram of the cross-section of an LED display module in another example;

[0022] Figure 2c For another example Figure 1 A schematic diagram of the AA section;

[0023] Figure 2d This is a structural schematic diagram of the cross-section of an LED display module in another example;

[0024] Figure 3a This is a structural schematic diagram of the cross-section of an LED display module in another example;

[0025] Figure 3b This is a structural schematic diagram of the cross-section of an LED display module in another example;

[0026] Figure 3c This is a structural schematic diagram of the cross-section of an LED display module in another example;

[0027] Figure 3d This is a structural schematic diagram of the cross-section of an LED display module in another example;

[0028] Figure 4a for Figure 4b Schematic diagram of the BB section;

[0029] Figure 4b This is a schematic diagram of the substrate structure in the method for manufacturing an LED display module provided in this application embodiment;

[0030] Figure 5a This is a schematic diagram of the structure of the substrate with a circuit layer and a circuit protection layer in the embodiments of this application;

[0031] Figure 5b This is a schematic diagram of the structure in this application embodiment where a carrier plate is disposed at the edge of the substrate;

[0032] Figure 5c This is a schematic diagram of the structure of the mold and encapsulation film on the substrate in the embodiments of this application;

[0033] Figure 6a This is a schematic diagram of the structure of the hot-press encapsulating adhesive on the substrate in the embodiments of this application;

[0034] Figure 6b This is a schematic diagram of the structure after hot-pressing encapsulation adhesive onto the substrate in an embodiment of this application;

[0035] Figure 6c This is a schematic diagram of the structure after hot-pressing encapsulation adhesive onto a substrate, as shown in another example of an embodiment of this application.

[0036] Figure 7a This is a schematic diagram of the structure of the hot-pressed encapsulating adhesive on the substrate, as shown in another example of an embodiment of this application.

[0037] Figure 7b This is a schematic diagram of the structure after hot-pressing encapsulation adhesive onto a substrate, as shown in another example of an embodiment of this application.

[0038] Figure 7c This is a schematic diagram of the structure after hot-pressing encapsulation adhesive onto a substrate, as shown in another example of an embodiment of this application.

[0039] Figure 8a This is a schematic diagram of a carrier plate disposed on the side of a substrate in an embodiment of the present invention. Figure 1 ;

[0040] Figure 8b This is a second schematic diagram of the structure in an embodiment of the present invention, showing a carrier plate disposed on the side of the substrate;

[0041] Figure 8c This is a schematic diagram (3) of the structure in an embodiment of the present invention, showing a carrier plate disposed on the side of the substrate;

[0042] Figure 8d This is a schematic diagram four of the structure in an embodiment of the present invention, showing a carrier plate disposed on the side of the substrate;

[0043] Figure 9 This is a schematic diagram of the front structure of the display screen after the LED display modules are spliced ​​together, as provided in an embodiment of the present invention.

[0044] Figure 10 for Figure 9 A schematic diagram of the CC section;

[0045] Figure 11 This is a schematic diagram of the cross-sectional structure of an existing LED display module;

[0046] Figure 12 The diagram shows a structural schematic of a carrier plate disposed on the side of a substrate in another embodiment;

[0047] Figure 13 As shown Figure 12 Schematic diagram of the DD cross section;

[0048] Figure 14 This is a structural schematic diagram of the cross-section of the LED display module in another embodiment; Implementation

[0049] The embodiments of this application are described in detail below, with examples of the embodiments shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the description of this application, "a plurality of" means two or more, and "a plurality of" means two or more, unless otherwise expressly specified.

[0050] The preferred embodiment of the manufacturing method for LED display modules used in splicing will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to this embodiment. Example

[0051] like Figures 1 to 2a As shown, the present invention provides an LED display module 100 for splicing. The LED display module 100 includes a substrate 1, a plurality of light-emitting units 2, and encapsulating adhesive 3. The substrate 1 includes an insulating base layer 11. The base layer 11 has a first surface and a second surface disposed opposite to each other, and a plurality of side surfaces connecting the first surface and the second surface. In this embodiment, the base layer is square, and there are four side surfaces between the first surface and the second surface. The first surface of the base layer 11 is provided with a first circuit layer 12, the second surface of the base layer 11 is provided with a second circuit layer 14, and at least one side surface of the base layer 11 is provided with a side circuit layer 13. The side circuit layer 13 at least partially connects the first circuit layer 12 and the second circuit layer 14, and the side circuit layer 13 makes the first circuit layer 12... At least a portion of the circuit between the first circuit layer 12 and the second circuit layer 14 is connected. Multiple light-emitting units 2 are mounted on the first circuit layer 12 of the substrate 1 and are connected to the external circuit through the side circuit layer 13 and the second circuit layer 14 in sequence. The material of the base layer 11 is preferably glass. Glass has the characteristics of high flatness and low expansion and contraction rate. The light-emitting units are arranged with small spacing on it, and the overall optical effect is not easily affected by changes in ambient temperature and humidity. In this embodiment, the first circuit layer 12 and the second circuit layer 14 are connected by setting the side circuit layer 13 on the side of the substrate 1. Compared with the prior art, which connects the circuits on both sides of the substrate by setting through holes in the substrate, the substrate 1 does not need to be drilled in this embodiment, and the overall structural strength is higher.

[0052] The light-emitting unit 2 in the aforementioned LED display module 100 can be a Mini LED chip, a Micro LED chip, or an LED package, preferably a flip-chip Mini LED chip. Multiple Mini LED chips can be any one of red, green, or blue Mini LED chips, or any combination thereof. Encapsulating adhesive 3 is fixed to the substrate 1 and covers the first circuit layer 12 and the light-emitting unit 2 on the first side of the base layer 11, as well as at least a portion of the side circuit layer 13. Encapsulating adhesive 3 can be epoxy resin or silicone resin. Encapsulating adhesive 3 has an upper surface 31 exposed to the LED display module 100 and orthogonal to the extension surface of the substrate side. The aforementioned LED display module 100 has a splicing side that can be used for splicing with adjacent LED display modules 100. Encapsulating adhesive 3 has a side surface 32 connected to the upper surface 31, forming at least a portion of the splicing side, and the side surface 32 of the encapsulating adhesive 3 is planar. At the splicing side position, the side surface 32 of the encapsulating adhesive and the upper surface 31 are connected by... The connection is at a right angle. Here, the right angle can be understood as 90 degrees or about 90 degrees, depending on whether it affects the splicing effect. In this embodiment, the side surface 32 of the encapsulating adhesive 3 located on the splicing side of the LED display module 100 and its adjacent upper surface 31 are connected at a right angle. This ensures that after the adjacent LED display modules 100 are spliced ​​together by splicing the splicing side, only the upper surface of the encapsulating adhesive 3 is exposed on the spliced ​​display screen at the splicing position. After splicing, only the upper surface of the encapsulating adhesive 3 serves as the light-emitting surface of the LED display screen at the splicing position. There are no rounded corners or beveled edges, thereby ensuring that the light emission effect of the LED display screen is consistent near the splicing position and far from the splicing position, improving the optical quality of the LED display screen and achieving a near-zero splicing seam effect.

[0053] In one embodiment, the first circuit layer 12, the second circuit layer 14, and the side circuit layer 13 have the same thickness, for example, 1-6 μm, preferably 2-3 μm. In practical applications, the thickness of the first circuit layer 12 and the second circuit layer 14 should not exceed 6 μm, otherwise it may cause slight deformation of the base layer 11. In other embodiments, the thicknesses of the first circuit layer 12, the second circuit layer 14, and the side circuit layer 13 may also be different; for example, the thickness of the side circuit layer 13 may be greater than the thickness of the first circuit layer 12. Since the side circuit layer 13 may be exposed on the side of the LED display module 100, its thickness being greater than that of the first circuit layer is beneficial for strengthening its mechanical strength and improving reliability.

[0054] In one embodiment, the first circuit layer 12, the second circuit layer 14, and the side circuit layer 13 are metal layers that are closely attached to the substrate and formed by a coating process such as magnetron sputtering or thermal evaporation.

[0055] In this embodiment, the function of the second circuit layer 14 is to provide a circuit interface for connecting the LED display screen to external circuits. Therefore, in this embodiment, the second circuit layer 14 only needs to partially cover the second side (i.e., the back side) of the base layer 11. In other embodiments, the second circuit layer 14 can also be extended to more uses, such as for connecting with other electronic components. Depending on the design requirements, the second circuit layer 14 can cover the entire second side of the base layer 11. This application does not limit the area, size, or form of the second circuit layer. However, in any case, the second circuit layer 14 will always be located on the second side of the base layer 11.

[0056] Because the side circuit layer 13 has a certain thickness, at least part of it will be exposed on the first surface of the base layer 11. Therefore, the encapsulating adhesive 3 will cover at least a portion of the side circuit layer 13 (i.e., the encapsulating adhesive 3 will at least contact a portion of the side circuit layer). Figure 2b As shown, the encapsulating adhesive 3 covers the top of the side circuit layer 3, and the side of the side circuit layer 13 is exposed on the side of the LED display module 100; as Figure 2c As shown, the encapsulating adhesive 3 covers the top and part of the side of the side circuit layer, and part of the side of the side circuit layer 13 is exposed on the side of the LED display module 100.

[0057] In this application, the side circuit layer 13 serves to connect the first circuit layer 12 and the second circuit layer 14. The number of side circuit layers 13 can be determined according to the circuit design requirements. For example, refer to... Figure 2d and Figure 3d As shown, a side circuit layer 13 can be provided only on one side of the base layer; for example, refer to Figure 2a , Figure 2b , Figure 2c , Figure 3a , Figure 3b , Figure 3c The side circuit layer 13 can also be set on two opposite sides; in addition, the side circuit layer can also be set on three or four sides.

[0058] In some examples of this embodiment, such as Figure 3a and Figure 3b , Figure 3c , Figure 3dAs shown, the first circuit layer 12 and the side circuit layer 13 of the LED display module 100 are covered with a circuit protection layer 15. This circuit protection layer 15 can be an ink layer with a thickness of 5~30µm, preferably 10~24µm. In this embodiment, the ink layer is preferably a black ink layer. If the LED display module 100 is used for a screen that directly displays information, a black ink layer can improve the contrast of the display screen. In other embodiments, the LED display module 100 can also be used for a transparent display screen. To achieve a transparent effect, the ink layer can be a transparent or semi-transparent ink layer, or no ink layer may be provided.

[0059] refer to Figure 3b and Figure 3c In some instances, since the circuit protection layer 15 covers the side circuit layer 13, in some manufacturing processes, a portion of the circuit protection layer 15 will be exposed on the side of the LED display module. The splicing side can be composed of the side of the circuit protection layer 15 and the side of the encapsulating adhesive.

[0060] refer to Figure 3a and 3d As shown, in some examples of this embodiment, the encapsulant 3 completely covers the side circuit layer 13, which can protect the side circuit layer 13 and the circuit protection layer 15 thereon to reduce wear. The side of the LED display module 100 with the side circuit layer is only composed of the side of the encapsulant 3 (i.e., the encapsulant covers the circuit protection layer). The encapsulant 3 extends to the back of the substrate (i.e., the side where the second side is located, opposite to the side where the light-emitting unit is located) and is flush with the back of the substrate. This structure sets the boundary between the circuit protection layer 15 and the encapsulant 3 at the bottom of the LED display module 100 (i.e., the part where the second side is located). In product design, the path for moisture to enter the interior of the LED display module 100 can be extended by increasing the substrate thickness. Example

[0061] In this embodiment, the LED display module is used to directly display images or text information. The LED display module uses small-sized LED light-emitting devices, such as Mini LED chips or Micro LED chips. Therefore, the LED display module can also be called a Mini LED display module or a Micro LED display module. In Mini LED display modules, small-sized LED light-emitting devices can be arranged with small spacing to achieve high resolution. However, due to cost considerations and limitations in the production capacity of existing equipment, multiple LED display modules are usually spliced ​​together to form a large-sized Mini LED display when manufacturing some large-sized Mini LED displays. During the manufacturing of LED display modules, light-emitting units are first fixed on the substrate, and then an encapsulating adhesive layer is used to cover the light-emitting units and the substrate. When covering the encapsulating adhesive layer, the encapsulating adhesive can be formed through a molding process. When using the molding process, a process edge to support the mold needs to be reserved around the perimeter of the substrate. After the encapsulating adhesive is formed by the mold, the excess process edge is cut off (therefore, the process edge can also be called the trimming edge, temporary edge, or mold support edge), reducing the edge width of the LED display module (i.e., the distance between the light-emitting unit closest to the edge on the substrate and the edge), so that the pixel pitch of each pixel is consistent during splicing. For ease of understanding, please refer to the invention patent application filed by the applicant on November 9, 2021, with patent number 202111166118.8 (publication date 2022-04-15). However, the LED display module provided in Embodiment 1 of this application must have a side circuit layer set during the substrate fabrication process, and then the encapsulating adhesive is molded. The encapsulating adhesive cannot be molded first and then the side circuit layer is fabricated. Furthermore, the side circuit layer can only be set after the process edge is cut off, which would result in the side where the side circuit layer is set being unable to use a mold to mold the encapsulating adhesive due to the lack of a process edge.

[0062] To address the above problems, this invention provides a method for manufacturing an LED display module 100 for splicing (see reference). Figures 4a to 8d (As shown) includes the following steps:

[0063] Step a: (Reference) Figure 4a and Figure 4bA flat substrate 1 is provided, the substrate 1 including an insulating base layer 11; the base layer 11 includes a first surface and a second surface opposite to each other, and a plurality of side surfaces connecting the first surface and the second surface; wherein the material of the base layer 11 is preferably glass, which has the characteristics of high flatness and low expansion and contraction rate, and the light-emitting units are arranged at small intervals on it, which is not easily affected by changes in ambient temperature and humidity. A first circuit layer 12 is provided on the first surface of the base layer 11, and a second circuit layer 14 is provided on the second surface of the base layer 11; wherein the process edge at the edge where the side circuit layer 13 needs to be provided on the side of the substrate 1 needs to be cut off to expose the side surface of the base layer and form the side circuit layer 13 on the side surface of the base layer; the side circuit layer 13 is provided on at least one side surface of the base layer 11. Figure 4a (Two side circuit layers are shown). Side circuit layer 13 enables at least a portion of the circuitry between the first circuit layer 12 and the second circuit layer 14 to be connected;

[0064] It should be noted that the portion of the substrate edge without a side circuit layer can retain process edge 5 (refer to...). Figure 4b Alternatively, the process edge can be left unretained (i.e., cut off), and this application does not impose any restrictions.

[0065] The first circuit layer 12, the side circuit layer 13, and the second circuit layer 14 are all disposed on the base layer 11. Specifically, they can be formed by coating processes such as magnetron sputtering and thermal evaporation. The first circuit layer 12 is provided with multiple pads corresponding to the electrodes of the light-emitting unit 2.

[0066] The present invention enables at least a portion of the circuit between the first circuit layer 12 and the second circuit layer 14 to be connected through the side circuit layer 13. Compared with the prior art, which sets through holes in a glass substrate to connect the circuits on both sides of the substrate, the substrate of the present invention has higher strength.

[0067] Step b: (Reference) Figure 4a and 4b A light-emitting unit is disposed on the first circuit layer. Multiple light-emitting units 2 are provided. The first circuit layer 12 has pads corresponding to the electrodes of the multiple light-emitting units 2. The multiple light-emitting units 2 are fixed to the first circuit layer 12 of the substrate 1 by soldering or by using conductive adhesive. The light-emitting unit 2 can be a Mini LED chip, a Micro LED chip, or an LED package, preferably a flip-chip Mini LED chip. The multiple Mini LED chips can be any one of red Mini LED chips, green Mini LED chips, or blue Mini LED chips, or any combination thereof. The size of the Mini LED chips ranges from 100µm to 200µm.

[0068] Step c: After completing step a or step b, refer to Figure 5a , Figure 8a , Figure 8b , Figure 8c , Figure 8d A carrier plate 4 (also referred to as an extended process edge or auxiliary process edge) is provided on the side of the substrate 1 where the process edge is missing (including the side where the side circuit layer 13 is provided). There is a gap between the side of the carrier plate 4 and the side of the substrate (i.e., there is also a gap between the side of the carrier plate 4 and the side circuit layer 13). The carrier plate 4 is preferably flat. When viewed along the direction projected onto the side of the substrate, the length of the side of the carrier plate 4 is greater than the length of the side of the substrate. In this embodiment, the relationship between the height of the side of the carrier plate and the height of the side of the substrate is not limited, but it is preferred that the height of the side of the carrier plate 4 is not greater than the height of the side of the substrate to save the material cost of the carrier plate 4.

[0069] Step d: Reference Figure 5c and Figure 6a , 6b 7a, 7b, provide mold 6 and semi-solid encapsulating film 30 ( Figure 5c As shown), a mold 6 is placed on the substrate 1 and the carrier plate 4, with at least a portion of the mold 6 abutting against the carrier plate 4. A semi-solid encapsulating adhesive is placed in the mold and vacuum hot-pressed, so that the semi-solid encapsulating adhesive film melts and covers the first surface of the substrate 1, the light-emitting unit 2 and at least a portion of the carrier plate 4. The upper surface of the encapsulating adhesive and the extension surface of the side of the substrate are orthogonal. After curing, a cured encapsulating adhesive is obtained.

[0070] In some embodiments, the encapsulating adhesive may be a thermosetting epoxy resin or a silicone resin.

[0071] In one embodiment, the mold includes a pressure plate 61 and a shim block 62. The shim block is placed on the process edge and / or the carrier plate. The shim block and the pressure plate cooperate to form a mold cavity. A semi-solid encapsulation film is placed in the mold cavity. The semi-solid encapsulation film is melted by pressing down and heating by the pressure plate, filling the mold cavity and covering the light-emitting unit.

[0072] Step e: Refer to Figure 6b , Figure 6c and Figure 7b , 7b Using a cutting tool, the cutting is performed parallel to the side of the substrate along the gap between the substrate side and the carrier plate 4 (i.e., along the side of the substrate). Figure 6b , Figure 6c and Figure 7a , 7b (At point a, indicated by the dotted line) the carrier plate 4, the colloid attached near the carrier plate 4, and the excess process edge 5 are removed to obtain the LED display module 100 (reference). Figure 1 , Figure 3a , Figure 3c (As shown in Figure 3d). The LED display module 100 has a splicing side, which includes the side surface of the encapsulating adhesive.

[0073] Since the carrier plate is usually harder than the encapsulating adhesive in order to stably support the mold, it is cut along the gap between the side of the carrier plate 4 and the side of the substrate 1. This way, only the encapsulating adhesive will be cut during cutting, and the carrier plate 4 will not be cut. This can increase the number of times the cutting tool can be used and improve the cutting efficiency.

[0074] In this embodiment, a first circuit layer 12, a side circuit layer 13, and a second circuit layer 14 are provided on a glass substrate 11, and the first circuit layer 12 and the second circuit layer 14 are connected through the side circuit layer 13. This avoids the glass substrate from being affected by the through holes. In this embodiment, when the encapsulating colloid is set by the mold, the auxiliary carrier plate 4 allows the mold to abut against the carrier plate 4. After the mold cavity is injected with colloid and vacuum hot-pressed, the colloid covers the first surface of the substrate 1, the light-emitting unit 2, and the carrier plate 4. The upper surface of the colloid is orthogonal to the extension surface of the side surface of the substrate. The carrier plate 4 and the colloid attached to the carrier plate 4 are cut off parallel to the side surface of the substrate along the gap between the side surface of the substrate 1 and the carrier plate 4. After the cut-off, the splicing side of the LED display module 100 is obtained. The splicing side includes the side surface of the remaining colloid after the cut-off, which is the encapsulating colloid 3. The colloid formed on the carrier plate 4 is removed by a cutting process, so that the side surface of the encapsulating adhesive 3 can be connected to the upper surface of the encapsulating adhesive 3 adjacent to the side surface by a right angle. When two LED display modules 100 are spliced ​​together to form a display screen, the splicing side can be tightly fitted by the right angle. In this embodiment, after the LED display modules 100 are spliced ​​into a display screen, only the upper surface of the encapsulating adhesive 3 is exposed to the display screen as the light-emitting surface of the display screen. This ensures that the difference in light emission effect of the display screen is very small at positions near and far from the splicing seam, improves the optical quality of the display screen, and improves the overall integrity of the display screen, achieving a near-zero splicing seam effect.

[0075] In some examples of this embodiment, in step b, the carrier plate 4 is fixed to at least one side of the substrate 1. During fixing, the carrier plate 4 and the substrate 1 can be arranged at a certain spacing and connected and fixed using an adhesive material such as tape 19. The tape prevents the molten encapsulating adhesive from overflowing from the gap between the substrate and the carrier plate onto the workbench surface or onto the back of the substrate during hot-pressing encapsulation, thus preventing the substrate from sticking to the workbench and becoming difficult to separate. In step e, the excess process edge and carrier plate 4 can be cut off first, and then the tape 19 can be removed; alternatively, the tape 19 can be removed first, and then the excess process edge and carrier plate 4 can be cut off.

[0076] In some examples of this embodiment, reference is made to Figure 6cAs shown, there is a gap between the carrier plate 4 and the substrate 1. During the lamination of the encapsulating adhesive, due to the adhesive's viscosity and surface tension, if the gap is too small, the adhesive may not completely fill the gap, resulting in space between the carrier plate 4 and the substrate 1. After removing the excess process edges and the carrier plate 4, the following can be obtained: Figure 3c The display module shown.

[0077] In some examples of this embodiment, because the substrate 1 typically has a process edge 5 during manufacturing, when components on the substrate 1 are close to the edge of the substrate 1, the process edge 5 of the substrate 1 can prevent damage to the substrate 1 or the components mounted on the substrate 1 during processing, such as... Figures 8a to 8c As shown, when fabricating the side circuit layer 13 on the substrate 1, only the process edge 5 corresponding to the side of the substrate where the side circuit layer 13 needs to be fabricated can be removed. The remaining process edge 5 can serve as a positioning reference for the carrier plate 4 when fixing it, so that the outer contour of the carrier plate 4 and the substrate 1 after combination forms a basically complete square to support the mold. In step d, when hot-pressing the encapsulated colloid, the mold can be simultaneously pressed against the process edge 5 and the carrier plate 4. After hot-pressing the encapsulated colloid, the remaining process edge 5 and the carrier plate 4 are removed. In this example, since the process edge 5 and the substrate 1 are integrated, the mold can be supported by the process edge 5 and the carrier plate 4, which can improve the stability of the mold during hot pressing and thus improve the quality of the finished product.

[0078] Specifically, in this embodiment, in step b, fixing the carrier plate 4 to at least one side of the flat substrate 1 can be done on one side of the substrate 1 (refer to...). Figure 8a ) or both sides (reference) Figure 8b ), three sides

[0079] (refer to Figure 8c Specifically, this can be determined based on the number of side circuit layers on substrate 1. (Refer to...) Figure 8d Alternatively, the process edges 5 of the substrate can be omitted, and side circuit layers 13 can be provided on all four sides of the substrate. During hot-press encapsulation, a carrier board 4 can be provided on all four sides. That is, in step a, the edges of the substrate can be left unprocessed. In other embodiments, even if some sides of the substrate do not have side circuit layers, the process edges of the substrate at these locations can be cut off or retained. The cut-off process edges expose the base layer side, and whether or not a side circuit layer needs to be provided can be determined according to the circuit design requirements.

[0080] In some examples of this embodiment, such as Figure 5a As shown, step a further includes providing a circuit protection layer 15 on the first circuit layer 12 and the side circuit layer 13. The circuit protection layer 15 may be an ink layer.

[0081] In some examples of this embodiment, the carrier plate 4 can be one of a glass plate, a stainless steel plate, a copper plate, a wood plate, or a resin plate. The material of the carrier plate 4 can also be the same as the material of the encapsulating adhesive.

[0082] The method for manufacturing an LED display module 100 provided by the present invention involves first removing the process edge at the edge of the substrate where the side circuit layer needs to be set, so as to facilitate the manufacturing of the side circuit layer; when molding the encapsulating adhesive, a carrier plate can be placed on the edge of the substrate where the process edge is missing (i.e., the edge where the side circuit layer is set), and the mold can be supported by the carrier plate, so that the encapsulating adhesive layer can be manufactured using the mold. Example

[0083] refer to Figure 12 (The shaded area in the image represents encapsulating adhesive 3) and Figure 13 As shown, based on the inspiration from Embodiment 1 and Embodiment 2 above, although some edges of the substrate may not have side circuit layers, the process edges at the corresponding edges can be cut off, that is, all process edges of the substrate can be cut off.

[0084] This embodiment provides a method for manufacturing LED display modules for splicing, characterized by the following steps:

[0085] Step a: Provide a substrate, the substrate including an insulating base layer, the base layer being made of glass, a first circuit layer being disposed on a first surface of the base layer, and a second circuit layer being disposed on a second surface of the base layer opposite to the first surface, the first circuit layer having a plurality of pads corresponding to the electrodes of the light-emitting unit; wherein, the process edges at each edge of the substrate are cut off to expose the side surface of the base layer, and a side circuit layer is disposed on at least a portion of the side surface of the base layer, the side circuit layer enabling at least a portion of the circuit between the first circuit layer and the second circuit layer to be conductive;

[0086] Step b: Provide light-emitting units on the plurality of pads on the first circuit layer.

[0087] Step c: A carrier plate is provided on each side edge of the substrate, and there is a gap between the side edge of the carrier plate and the side edge of the substrate;

[0088] Step d: Provide a mold and a semi-solid encapsulating film. Place the mold on the substrate and the carrier plate, so that at least a part of the mold abuts against the carrier plate. Set the semi-solid encapsulating film in the mold and perform vacuum hot pressing, so that the semi-solid encapsulating film melts and covers the first side of the substrate, the light-emitting unit, and at least a part of the carrier plate and at least a part of the gap between the substrate and the carrier plate, forming an encapsulating adhesive. The upper surface of the encapsulating adhesive is orthogonal to the extension surface of the side of the substrate. After curing, a cured encapsulating adhesive is obtained.

[0089] Step e: Using a cutting tool, cut away the carrier plate and the encapsulating adhesive attached to it along the gap between the substrate side and the carrier plate, parallel to the substrate side, to obtain the LED display module. (See details...) Figure 13 Excess encapsulant and carrier board are removed along the position of dashed line a to obtain Figure 14 The LED display module shown.

[0090] The advantages of the above method are that, during the molding of the encapsulating adhesive, regardless of whether the substrate has a side circuit layer, the encapsulating adhesive can at least partially fill the gap between the substrate and the carrier plate, thereby wrapping the substrate around its perimeter and providing comprehensive protection for the side edges of the substrate. This results in good airtightness between the substrate and the encapsulating adhesive, preventing moisture from easily intruding into the light-emitting device. Simultaneously, in step e, when removing excess carrier plate and encapsulating adhesive, the cutting tool is entirely focused on cutting the encapsulating adhesive. Since the encapsulating adhesive is relatively soft and easy to cut, it avoids simultaneously cutting the harder substrate and the softer encapsulating adhesive, preventing gaps from forming between the substrate and the encapsulating adhesive due to different stresses from the cutting tool during cutting.

[0091] refer to Figure 14 For example, the LED display module has a side circuit layer on only one side of the substrate, but the other edges are covered with encapsulant to protect the sides of the substrate; and the path for moisture to enter the light-emitting unit 2 is long, and the airtightness between the sides of the substrate and the encapsulant is good. Example

[0092] like Figures 9 to 10 As shown, an LED display screen is provided in this embodiment, which is spliced ​​together using LED display modules 100 of Embodiment 1. The LED display modules 100 are connected by connectors (not shown), and then the connectors are tightly fixed to the outer frame of the structure by copper pillars to form an LED display screen with very small splicing seams. The spliced ​​LED display screen provided in this embodiment has good consistency between the optical visual effect near the splicing seam and the optical visual effect far from the splicing seam, and can achieve a display effect close to zero splicing seam.

[0093] The above are several embodiments provided by the present invention. It should be understood that the application of the present invention is not limited to the examples described above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. In the above embodiments, features can be combined, interchanged, reused, etc., to form new embodiments without conflict. All of these fall within the scope of the embodiments of the present invention.

Claims

1. A manufacturing method of an LED display module for splicing, characterized in that, The method comprises the following steps: Step a: providing a substrate, the substrate comprising an insulating base layer made of glass material, a first circuit layer arranged on a first surface of the base layer, and a second circuit layer arranged on a second surface of the base layer opposite to the first surface, the first circuit layer being provided with a plurality of pads corresponding to electrodes of light-emitting units; wherein the process edge of the edge of the substrate where the side circuit layer is arranged needs to be cut off to expose the side surface of the base layer and form a side circuit layer at the side surface of the base layer, the side circuit layer making at least part of the circuit between the first circuit layer and the second circuit layer conductive; Step b: arranging the light-emitting units on the plurality of pads on the first circuit layer; Step c: arranging a carrier plate on the side surface of the substrate where the process edge is removed; there is a gap between the side surface of the carrier plate and the side surface of the substrate; Step d: providing a mold and a semi-solid encapsulating adhesive film, placing the mold on the substrate and the carrier plate so that at least part of the mold abuts against the carrier plate, arranging the semi-solid encapsulating adhesive film in the mold and performing vacuum hot pressing, so that the semi-solid encapsulating adhesive film melts and covers the first surface of the substrate, the light-emitting units, and at least part of the carrier plate to form an encapsulating adhesive, the upper surface of the encapsulating adhesive being orthogonal to the extension surface of the side surface of the substrate, and obtaining a solidified encapsulating adhesive after solidification; Step e: cutting off the carrier plate, the encapsulating adhesive attached to the carrier plate, and the excess process edge parallel to the side surface of the substrate along the gap between the side surface of the substrate and the carrier plate to obtain an LED display module.

2. The manufacturing method of the LED display module according to claim 1, characterized in that, In the step d, the encapsulating adhesive at least partially fills or completely fills the gap between the side surface of the carrier plate and the side circuit layer.

3. The manufacturing method of the LED display module according to claim 1, characterized in that, In the step a, after the first circuit layer, the second circuit layer, and the side circuit layer are arranged, a step of arranging a circuit protection layer on the first circuit layer and the side circuit layer is further included.

4. The manufacturing method of the LED display module according to claim 1, characterized in that, In the step b, the bottom of the carrier plate is connected to the second surface of the base layer through an adhesive tape.

5. A manufacturing method of an LED display module for splicing, characterized in that, The method comprises the following steps: Step a: providing a substrate, the substrate comprising an insulating base layer made of glass material, a first circuit layer arranged on a first surface of the base layer, and a second circuit layer arranged on a second surface of the base layer opposite to the first surface, the first circuit layer being provided with a plurality of pads corresponding to electrodes of light-emitting units; wherein the process edge of the edge of the substrate where the side circuit layer is arranged needs to be cut off to expose the side surface of the base layer and form a side circuit layer at the side surface of the base layer, the side circuit layer making at least part of the circuit between the first circuit layer and the second circuit layer conductive; Step b: arranging the light-emitting units on the plurality of pads on the first circuit layer; Step c: arranging a carrier plate on the side surface of the substrate where the process edge is removed; there is a gap between the side surface of the carrier plate and the side surface of the substrate; Step d: providing a mold and a semi-solid encapsulation adhesive film, placing the mold on the substrate and the carrier plate, with at least a part of the mold abutting against the carrier plate, setting the semi-solid encapsulation adhesive film in the mold and performing vacuum hot pressing, so that the semi-solid encapsulation adhesive film melts and covers the first surface of the substrate, the light-emitting unit, and at least part of the carrier plate and the gap between the substrate and the carrier plate, to form an encapsulation adhesive, the upper surface of the encapsulation adhesive and the extended surface of the substrate side are orthogonal, and the cured encapsulation adhesive is obtained after solidification; Step e: cutting the carrier plate and the encapsulation adhesive attached to the carrier plate along the gap between the substrate side and the carrier plate and parallel to the substrate side by a cutting tool, to obtain an LED display module.

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