A method for manufacturing an LED transparent display screen

Abstract

The application discloses a kind of LED transparent display screen's manufacturing method, belong to LED display technical field, including the following steps: material and pretreatment, laser etching, LED chip die bonding, integrated lamination package, wherein single conductive film is etched once, multiple row electrodes of display area, cathode passage and multiple row electrode lead-out area, cathode passage lead-out end of non-display area are formed on conductive film etching, each LED chip is fixedly installed at the intersection node of one row electrode and one cathode passage, so that LED chip anode is electrically connected with row electrode, and LED chip cathode is electrically connected with cathode passage.The application completely abandons additional substrate, exclusive film coating, entity wire layout and other processes, only single-sided laser etching is used to complete full circuit layout, process flow is shortened by more than 30%, without high-end special equipment, and mass production can be realized by purchasing commercially available substrate, industry access threshold is greatly reduced, production cost is greatly reduced, and mass production yield is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of LED display technology, and in particular to a method for manufacturing a transparent LED display screen. Background Technology

[0002] With the rapid development of large-screen display systems, urban lighting projects, and commercial window displays, the application scenarios for LED displays are becoming increasingly widespread, placing higher demands on their performance, appearance, and overall cost. Compared to traditional outdoor displays, LED displays, with their significant advantages such as energy saving and environmental protection, long service life, clear display effects, and fast response speed, have gradually replaced traditional displays as the mainstream choice. Among them, transparent LED displays, due to their high light transmittance, low management costs, high aesthetic appeal, and ability to blend perfectly with architecture and the environment, are finding increasingly widespread application in various high-end display scenarios, and market demand continues to rise.

[0003] Currently, the common LED display manufacturing process in the industry generally includes the following steps: First, a conductive film is deposited on a transparent substrate, and after double-sided etching, a complete conductive circuit is constructed by printing or laying solid metal wires; then, LED beads are fixed on the conductive circuit by reflow soldering or laser welding to achieve electrical connection between the beads and the circuit; finally, non-conductive transparent optical adhesive and glass panel are covered in sequence, and encapsulation is completed through lamination process to finally form the finished LED display.

[0004] However, the existing manufacturing processes have many shortcomings, which not only lead to high overall production costs but also limit the improvement of core performance characteristics of LED transparent displays, such as light transmittance and mass production yield. Specifically, the process requires an additional transparent substrate and involves cumbersome steps such as the deposition of a dedicated conductive film and the laying of physical metal wires, making the process complex. At the same time, the deposition of the conductive film requires specialized coating equipment, which places high demands on production technology, significantly raising the industry's entry barrier and increasing the initial investment for companies.

[0005] Furthermore, during the production process, issues such as double-sided etching alignment errors, solid metal wires blocking light, and air bubbles generated during multi-layer packaging can easily occur. These issues directly lead to the difficulty in achieving a light transmittance of over 85% and a mass production yield of less than 75% for existing LED transparent display products. This further increases production losses and overall costs, failing to fully meet the market's core demands for high light transmittance, low cost, and high yield of LED transparent displays. Therefore, a more optimized LED transparent display manufacturing method is urgently needed to solve the aforementioned technical pain points. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing an LED transparent display screen with relatively simple process, high light transmittance, and low mass production cost.

[0007] The objective of this invention is achieved through the following technical solution: An LED transparent display screen includes the following steps: Material selection and pretreatment: Commercially available PET-based transparent conductive film is selected and cut into single conductive films. Each single conductive film includes a substrate layer and a conductive layer. The conductive layer is attached to the substrate layer, and the single conductive film is cleaned and pretreated. Laser etching: A single conductive film is laser etched to form multiple row electrodes and cathode pathways in the display area, and multiple row electrode lead-out areas and cathode pathway lead-out ends in the non-display area; wherein the multiple row electrodes are arranged parallel to each other along the width direction of the conductive layer, each row electrode is composed of a conductive area between two sets of parallel laser etching lines, and the multiple cathode pathways are arranged along the length direction of each row electrode, each cathode pathway is composed of a conductive area between two adjacent sets of L-shaped etching lines. LED chip die bonding: Each LED chip is fixedly installed at the intersection of a row electrode and a cathode path, so that the anode of the LED chip is electrically connected to the row electrode and the cathode of the LED chip is electrically connected to the cathode path. Integrated bonding and encapsulation: A filler layer is filled between adjacent LED chips, and the protective film layer is integrated and bonded to the LED chip and circuit layer through the filler layer.

[0008] Furthermore, the method for manufacturing the LED transparent display screen also includes a step of printing and curing conductive silver paste. This step is located between the material sampling and pretreatment step and the laser etching step. Specifically, it involves pre-printing conductive silver paste on the non-display area at the edge of a single conductive film and then drying and curing it.

[0009] Furthermore, in the step of printing and curing conductive silver paste, the screen mesh count is 250-400 mesh, the width of the silver paste lead-out line is 3-8mm, and the silver paste thickness is 15-30μm; after printing, it is placed in an oven for high-temperature curing at a temperature of 100-150℃ for 20-60 minutes; after curing, the silver paste thickness is 10-20μm, the surface resistance of the cured silver paste is ≤0.2 Ω / □, and the adhesion grade is ≥4B.

[0010] Furthermore, in the laser etching step, the conductive film and conductive silver paste are simultaneously laser etched once using a laser etching device. The non-display area at the edge of the conductive layer is etched to form multiple row electrode lead-out areas and cathode path lead-out terminals. Multiple mutually insulated edge silver paste lead-out areas are etched on the conductive silver paste. A portion of the edge silver paste lead-out areas are connected to each of the row electrode lead-out areas, and another portion of the edge silver paste lead-out areas are connected to each of the column cathode path lead-out terminals.

[0011] Furthermore, the method for manufacturing the LED transparent display screen also includes a control circuit board edge integration step, specifically: hot-pressing the metal ends of each flexible flat cable branch at one end of the main flexible flat cable to an edge silver paste lead-out area, and connecting the combined circuit at the other end of the main flexible flat cable to the signal conversion interface of the control circuit board.

[0012] Furthermore, in the edge integration step of the control circuit board, the hot pressing temperature is 120℃-150℃, the pressure is 0.3-0.5MPa, the time is 10-20s, and the contact resistance after the metal end of each of the flexible flat cable branches is connected to the corresponding edge silver paste lead-out area is ≤0.5Ω.

[0013] Furthermore, in the laser etching step, when the conductive film is metallic silver or silver alloy PET conductive film, the laser etching equipment emits an infrared laser with a wavelength of 1064nm, a power of 8-12W, an etching speed of 20-30mm / s, and a focusing accuracy of ±5μm; when the conductive film is an ITO PET conductive film, the laser etching equipment emits an ultraviolet laser with a wavelength of 355nm, a power of 5-8W, an etching speed of 30-50mm / s, and a focusing accuracy of ±5μm.

[0014] Furthermore, in the LED chip die bonding step, a room temperature die bonding process is adopted. The LED chip is fixedly installed at the intersection of the row electrode and the cathode path using conductive silver paste. The die bonding temperature is 15-35℃, the pressure is 0.1-0.3MPa, and the thermal curing temperature is 150℃ for 30 minutes to ensure that the connection resistance between the LED chip and the row electrode and the cathode path is ≤0.1Ω.

[0015] Furthermore, in the integrated bonding and encapsulation step, the filler layer is OCA adhesive, transparent silicone, or transparent epoxy resin, and the thickness of the filler layer is greater than the height of the LED chip, with a thickness of 0.15-0.30 mm; the protective film layer is optical grade PET or transparent polycarbonate film, with a thickness of 50-150 μm, and the outer side is hardened to a hardness ≥4H and a light transmittance ≥92%.

[0016] Compared with existing technologies, the method for manufacturing an LED transparent display screen of the present invention has the following advantages: (1) This application completely eliminates the processes of additional substrate, special coating, and physical wire laying. The entire circuit layout is completed by single-sided laser etching, which shortens the process flow by more than 30%. No high-end special equipment is required. Mass production can be carried out by purchasing commercially available substrates. The industry entry threshold is greatly reduced, the production cost is greatly reduced, and the mass production yield is greatly improved.

[0017] (2) This application adopts a room temperature die bonding process, which uses conductive silver paste to directly fix the LED chip at the intersection of the row electrode and the cathode path. The chip anode is electrically connected to the row electrode, and the chip cathode is electrically connected to the cathode path. There are no additional solder pads, physical leads, or printed wires, which completely avoids light shading and maximizes the transparent display effect. At the same time, it does not interfere with the touch detection function of electrode reuse, so that the display driving and touch signal transmission remain stable.

[0018] (3) In this application, the main line of the flexible flat cable, the microcontroller, the LED driver chip, the power supply interface and the signal conversion interface are integrated on an independently set control circuit board and connected to the display module through the main line of the flexible flat cable. The control circuit board is located in the non-display area outside the module, does not occupy the display area, and does not affect the overall light transmittance and appearance integrity of the module. At the same time, a current limiting resistor is set to ensure the safe operation of the circuit and the accuracy of touch detection. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the manufacturing method of the LED transparent display screen of the present invention; Figure 2 For the process Figure 1 A schematic diagram of the circuit on the conductive film after the laser etching step in the manufacturing method of LED transparent display screen. Figure 3 For the process Figure 1 Another schematic diagram of the conductive film after the laser etching step in the manufacturing method of LED transparent display screen.

[0020] Figure 4 According to Figure 1 A schematic diagram of the structure of an LED transparent display screen manufactured using the LED transparent display screen manufacturing method; Figure 5 for Figure 4 Cross-sectional view of an LED transparent display screen.

[0021] In the diagram: 10, Substrate layer; 20, Conductive layer; 30, Circuit layer; 31, Linear layer; 311, Row electrode; 3111, Parallel laser etching line; 312, Cathode path; 3121, L-shaped etching line; 3121a, Horizontal etching line; 3121b, Vertical etching line; 32, Main line of flexible flat cable; 321, Branch line of flexible flat cable; 322, Combined circuit; 40, LED chip; 41, Chip anode; 42, Chip cathode; 50, Encapsulation layer; 51, Filler layer; 52, Protective film layer; 60, Control circuit board; 61, Microcontroller; 62, LED driver chip; 63, Power supply interface; 64, Signal conversion interface; 65, Current limiting resistor; 66, Power management unit. Detailed Implementation

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, a method for manufacturing an LED transparent display screen includes the following steps: Material selection and pretreatment: Commercially available PET-based transparent conductive film is selected and cut into single conductive films. Each single conductive film includes a substrate layer 10 and a conductive layer 20. The conductive layer 20 is attached to the substrate layer 10, and the single conductive film is cleaned and pretreated. Printed and cured conductive silver paste: Conductive silver paste is pre-printed on the non-display areas at the edges of a single conductive film and then dried and cured. Laser etching: A single conductive film is laser etched to form row electrodes 311 and cathode passages 312 for the display area, as well as row electrode lead-out areas and cathode passage lead-out ends for the non-display area. Multiple row electrodes 311 are arranged parallel to each other along the width direction of the conductive layer 20. Each row electrode 311 is composed of a conductive area between two sets of parallel laser etching lines 3111. Multiple cathode passages 312 are arranged along the length direction of each row electrode 311. Each cathode passage 312 is composed of a conductive area between two adjacent sets of L-shaped etching lines 3121. LED chip die bonding: Each LED chip 40 is fixedly installed at the intersection of a row electrode 311 and a cathode passage 312, so that the LED chip anode 41 is electrically connected to the row electrode 311 and the LED chip cathode 42 is electrically connected to the cathode passage 312. Integrated bonding and encapsulation: A filler layer 51 is filled between adjacent LED chips 40, and the protective film layer 52 is integrated and bonded to the LED chip 40 and the circuit layer 30 through the filler layer 51. Edge integration of control circuit board: The metal ends of each flexible flat cable branch line 321 at one end of the main flexible flat cable 32 are respectively heat-pressed and bonded to an edge silver paste lead-out area, and the combined line 322 at the other end of the main flexible flat cable 32 is correspondingly plugged into the signal conversion interface 64 of the control circuit board 60.

[0026] In the material selection and pretreatment steps, commercially available conventional silver alloy conductive film (thickness 125μm, surface resistance 7.5Ω / □, light transmittance 90%) is selected and cut to the target display size (e.g., 200mm×300mm). A plasma cleaning machine is used for surface impurity removal. Process parameters: power 100W, cleaning time 30s, surface water contact angle ≤28° after cleaning, removing surface oil and dust impurities, and set aside for later use.

[0027] In the printing and curing of conductive silver paste, the screen mesh count is 250-400 mesh, the lead width of the printed silver paste is 3-8 mm, and the silver paste (wet film) thickness is 15-30 μm. After printing, it is placed in an oven for high-temperature curing at 100-150℃ for 20-60 minutes. After curing, the silver paste thickness is 10-20 μm, the surface resistance is ≤0.2 Ω / □, and the adhesion grade is ≥4B. In this embodiment, the screen mesh count is 300 mesh, the lead width of the printed silver paste is 5 mm, and the silver paste (wet film) thickness is 20 μm. After printing, it is placed in an oven for high-temperature curing at 120℃ for 30 minutes. After curing, the silver paste thickness is 15 μm, the surface resistance is ≤0.1 Ω / □, and the adhesion grade is ≥5B.

[0028] In the laser etching step, the conductive film and conductive silver paste are simultaneously laser etched by a laser etching device. The non-display area at the edge of the conductive layer 20 is etched to form multiple row electrode lead-out areas and cathode path lead-out ends. Multiple mutually insulated edge silver paste lead-out areas are etched on the conductive silver paste. Some of the edge silver paste lead-out areas are connected to each row electrode lead-out area, and the other part of the edge silver paste lead-out areas are connected to each column cathode path lead-out end.

[0029] When the conductive film is metallic silver or silver alloy PET conductive film, the laser etching equipment emits an infrared laser with a wavelength of 1064nm, a power of 8-12W, an etching speed of 20-30mm / s, and a focusing accuracy of ±5μm; when the conductive film is ITO PET conductive film, the laser etching equipment emits an ultraviolet laser with a wavelength of 355nm, a power of 5-8W, an etching speed of 30-50mm / s, and a focusing accuracy of ±5μm.

[0030] In the LED chip die bonding step, a room-temperature die bonding process is adopted. The LED chip 40 is fixedly installed at the intersection of the horizontal electrode 311 and the cathode passage 312 using conductive silver paste. There are no additional solder pads, physical leads, or printed wires, which completely avoids light obstruction and maximizes the transparent display effect, while not interfering with the touch detection function of electrode reuse. The die bonding temperature is 15-35℃, the pressure is 0.1-0.3MPa, and the thermal curing temperature is 150℃ for 30 minutes to ensure that the connection resistance between the LED chip 40 and the horizontal electrode 311 and the cathode passage 312 is ≤0.1Ω, with no loose connections or poor conductivity, so that the display driving and touch signal transmission remain stable.

[0031] In the integrated bonding and encapsulation process, a double-layer encapsulation of filler layer 51 and protective film layer 52 is adopted to protect LED chip 40, line layer 31 etched on conductive film and edge silver paste lead-out area. Moreover, the encapsulation layer 50 is thinner, has higher flatness and stronger protection performance.

[0032] The filler layer 51 is made of OCA adhesive, transparent silicone, or transparent epoxy resin. The thickness of the filler layer 51 is greater than the height of the LED chip 40, and the thickness of the filler layer 51 is 0.15-0.30mm. The protective film layer 52 is made of optical grade PET or transparent polycarbonate film with a thickness of 50-150μm. The outer side is hardened (pencil hardness test) with a hardness ≥4H, and has anti-scratch, anti-fouling, and abrasion-resistant properties, with a light transmittance ≥92%. The two layers are stacked in sequence to perform integrated vacuum pressing and encapsulation of the module. Pressing parameters: pressure 0.4MPa, temperature 30℃, duration 45s, followed by debubbling treatment for 10min to ensure no bubbles or ghosting during bonding.

[0033] In the edge integration step of the control circuit board, the hot pressing temperature is 120℃-150℃, the pressure is 0.3-0.5MPa, and the time is 10-20s. The contact resistance after the metal end of each flexible flat cable branch 321 is connected to the corresponding edge silver paste lead-out area is ≤0.5Ω, and the conduction is stable.

[0034] This application completely eliminates the need for additional substrates, dedicated coatings, and physical wire laying processes. It completes the entire circuit layout solely through single-sided laser etching, shortening the process flow by more than 30%. It eliminates the need for high-end specialized equipment and allows for mass production by purchasing commercially available substrates. This significantly lowers the industry entry barrier, reduces production costs, and greatly improves mass production yield.

[0035] This application employs a room-temperature die bonding process, using conductive silver paste to directly fix the LED chip 40 to the intersection of the row electrode 311 and the cathode path 312. The chip anode 41 is electrically connected to the row electrode, and the chip cathode 42 is electrically connected to the cathode path 312. There are no additional solder pads, physical leads, or printed wires, which completely avoids light obstruction and maximizes the transparent display effect. At the same time, it does not interfere with the touch detection function of electrode reuse, so that both display driving and touch signal transmission remain stable.

[0036] This application integrates the main flexible flat cable 32, microcontroller 61, LED driver chip 62, power supply interface 63, and signal conversion interface 64 onto a separately set control circuit board 60, which is connected to the display module through the main flexible flat cable 32. The control circuit board 60 is located in the non-display area outside the module, does not occupy the display area, and does not affect the overall light transmittance and appearance integrity of the module. At the same time, a current limiting resistor 65 is provided to ensure the safe operation of the circuit and the accuracy of touch detection.

[0037] like Figure 4-5 As shown, this application also relates to an LED transparent display screen manufactured according to the above manufacturing method, including a conductive film, a circuit layer 30, a plurality of LED chips 40, an encapsulation layer 50, and a control circuit board 60. The conductive film includes a substrate layer 10 and a conductive layer 20.

[0038] The circuit layer 30 includes a line layer 31 and a flexible flat cable main line 32. The conductive layer 20 is etched with the line layer 31. The line layer 31 includes multiple row electrodes 311 and cathode passages 312 located in the display area, and multiple row electrode lead-out areas and cathode passage lead-out terminals located in the edge non-display area.

[0039] The width of the row electrode 311 is 0.4-1.0 mm. Each group of L-shaped etching lines 3121 includes a horizontal etching line 3121a and a vertical etching line 3121b. The horizontal etching line 3121a is parallel to the parallel laser etching line 3111 and intersects the vertical etching line 3121b perpendicularly. The distance between the two horizontal etching lines 3121a of the two groups of L-shaped etching lines 3121 is 0.3 mm-1.0 mm.

[0040] Each group of parallel laser etching lines 3111 includes multiple parallel laser etching lines. The spacing between two adjacent parallel etching lines and the width of a single parallel etching line are both 0.03mm-0.05mm to ensure clear electrode boundaries and prevent conductive adhesion between adjacent independent conductive areas. Each group of L-shaped etching lines 3111 includes multiple L-shaped etching lines. The spacing between two adjacent horizontal etching lines 3121a and the width of a single horizontal etching line 3121a and vertical etching line 3121b are both 0.03mm-0.05mm to ensure reliable insulation and prevent conductive adhesion. In this embodiment, each group of parallel laser etching lines 3111 includes two parallel laser etching lines, and each group of L-shaped etching lines 3111 includes two L-shaped etching lines.

[0041] One end of the main flexible flat cable 32 extends to form multiple flexible flat cable branches 321, and the other end of the main flexible flat cable 32 forms a plug-in terminal. The plug-in terminal is provided with a total line 322 equal in number to the flexible flat cable branches 321. Some of the flexible flat cable branches 321 are connected to the corresponding electrode lead-out areas of each row, and the other part of the flexible flat cable branches 321 are connected to the corresponding cathode path lead-out terminals of each column.

[0042] In this embodiment, there are 8 edge silver paste lead-out areas, 8 flexible flatbed cable branch lines 321, and 8 aggregated lines 322. 4 flexible flatbed cable branch lines 321 are connected to 4 row electrode lead-out areas, and 4 flexible flatbed cable branch lines 321 are connected to 4 column cathode path lead-out ends. That is, 1 flexible flatbed cable branch line 321 is connected to 4 cathode path lead-out ends in one column. Each cathode path 312 is connected to the flexible flatbed cable branch line 321 in sequence and then aggregated to the flexible flatbed cable main line 32 to form a complete column electrode. That is, the 8 aggregated lines 322 are 4 row electrode connection lines and 4 column electrode connection lines, thus finally realizing an n×n matrix electrode layout on a single conductive film.

[0043] The control circuit board 60 integrates a microcontroller 61, an LED driver chip 62, a power supply interface 63, a signal conversion interface 64, a current limiting resistor 65, and a power management unit 66. It is integrated into the non-display area at the edge of the conductive film, and the edge width after integration is ≤10mm, forming an integrated control module that does not occupy the effective display area, does not destroy the overall transparent visual effect, and has a compact structure and simple installation.

[0044] The microcontroller 61 has a built-in communication module. The microcontroller 61 is electrically connected to the LED driver chip 62 and communicates with the LED driver chip 62 through the communication module to control the operation of the LED driver chip 62. In this embodiment, the microcontroller integrates wireless communication and main control functions, preferably using an ESP32-S3 series module with built-in WiFi / Bluetooth and an integrated onboard antenna for wireless data transmission, remote control, and display content updates. Simultaneously, as the system's timing core, the microcontroller executes a second-level time-division multiplexing control strategy. Through software-preset fixed working cycles, it coordinates the orderly switching of the drive unit between the display stage and the touch detection stage, verifying touch signals, determining coordinates, and managing modes to ensure both display continuity and touch reliability.

[0045] A dedicated LED row and column driver chip is used, preferably the TLC6983 series driver chip. Electrode reuse is achieved under the coordination of the microcontroller, and the LED display driving and self-capacitance touch detection are completed in a time-division manner through the same set of row and column electrodes. In this embodiment, a low-power dedicated LED driver chip 62 is selected, which supports row and column scanning driving, operates at a DC power supply of ≤5V, has a standby power consumption of ≤0.1W, and an operating power consumption of ≤150W / m².

[0046] When it is necessary to expand the number of rows and columns of the LED array (such as upgrading from 16×16 to 32×32, 64×64 or other larger arrays), the display and touch driving unit supports channel expansion by adding the same type of driving chip (such as the TLC6983 series).

[0047] The power supply interface 63 is electrically connected to the microcontroller 61. The power supply interface 63 adopts a miniature hidden USB-C interface, which is adapted to low power consumption requirements and is used to provide a stable operating voltage for the microcontroller 61 and the LED driver chip 62.

[0048] The signal adapter interface 64 is electrically connected to the LED driver chip 62, and the plug-in end is plugged into the signal adapter interface 64.

[0049] The current-limiting resistor 65 can be set individually or shared by multiple electrodes. Its resistance is 100 kΩ-1 MΩ. It is used to clear charge in conjunction with timing control before and during touch detection.

[0050] The power management unit 66 is electrically connected to the microcontroller 63. The power management unit 66 uses a low-voltage linear regulator chip, preferably the AMS1117-3.3 series regulator chip, to convert the external 5V power supply into a stable 3.3V voltage and power the LED driver chip 62. The power management unit 66 has sufficient output current margin to adapt to different load states during the time-sharing switching process of display driving and touch detection, so as to ensure continuous and stable system operation.

[0051] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for manufacturing an LED transparent display screen, characterized in that, Includes the following steps: Material selection and pretreatment: Select commercially available PET-based transparent conductive film, cut it into single conductive films, each of which includes a substrate layer (10) and a conductive layer (20). The conductive layer (20) is attached to the substrate layer (10), and the single conductive film is cleaned and pretreated. Laser etching: A single conductive film is laser etched once to form multiple row electrodes (311) and cathode passages (312) for the display area, and multiple row electrode lead-out areas and cathode passage lead-out ends for the non-display area; wherein the multiple row electrodes (311) are arranged parallel to each other along the width direction of the conductive layer (20), each row electrode (311) is composed of a conductive area between two sets of parallel laser etching lines (3111), and the multiple cathode passages (312) are arranged along the length direction of each row electrode (311), each cathode passage (312) is composed of a conductive area between two adjacent sets of L-shaped etching lines (3121); LED chip die bonding: Each LED chip (40) is fixedly installed at the intersection of a row electrode (311) and a cathode path (312), so that the LED chip anode (41) is electrically connected to the row electrode (311) and the LED chip cathode (42) is electrically connected to the cathode path (312). Integrated bonding and encapsulation: A filler layer (51) is filled between adjacent LED chips (40), and the protective film layer (52) is integrated and bonded to the LED chip (40) and the circuit layer (30) through the filler layer (51).

2. The method for manufacturing an LED transparent display screen according to claim 1, characterized in that: The method for manufacturing the LED transparent display screen further includes a step of printing and curing conductive silver paste. This step is located between the material sampling and pretreatment step and the laser etching step. Specifically, it involves pre-printing conductive silver paste on the non-display area at the edge of a single conductive film and then drying and curing it.

3. The method for manufacturing an LED transparent display screen according to claim 2, characterized in that: In the printing and curing of conductive silver paste, the screen mesh count is 250-400 mesh, the width of the printed silver paste lead is 3-8mm, and the silver paste thickness is 15-30μm. After printing, it is placed in an oven for high-temperature curing at 100-150℃ for 20-60 minutes. After curing, the silver paste thickness is 10-20μm, the surface resistance of the cured silver paste is ≤0.2 Ω / □, and the adhesion grade is ≥4B.

4. The method for manufacturing an LED transparent display screen according to claim 2, characterized in that: In the laser etching step, the conductive film and conductive silver paste are simultaneously laser etched by a laser etching device. The non-display area at the edge of the conductive layer (20) is etched to form multiple row electrode lead-out areas and cathode path lead-out ends. Multiple mutually insulated edge silver paste lead-out areas are etched on the conductive silver paste. A portion of the edge silver paste lead-out areas are connected to each row electrode lead-out area, and another portion of the edge silver paste lead-out areas are connected to each column of cathode path lead-out ends.

5. The method for manufacturing an LED transparent display screen according to claim 4, characterized in that: The manufacturing method of the LED transparent display screen also includes a control circuit board edge integration step, specifically: the metal ends of each flexible flat cable branch (321) at one end of the main flexible flat cable (32) are respectively hot-pressed together at the edge silver paste lead-out area, and the combined line (322) at the other end of the main flexible flat cable (32) is correspondingly plugged into the signal conversion interface (64) of the control circuit board (60).

6. The method for manufacturing an LED transparent display screen according to claim 5, characterized in that: In the edge integration step of the control circuit board, the hot pressing temperature is 120℃-150℃, the pressure is 0.3-0.5MPa, and the time is 10-20s. The contact resistance of the metal end of each of the flexible flat cable branches (311) after being connected to the corresponding edge silver paste lead-out area is ≤0.5Ω.

7. The method for manufacturing an LED transparent display screen according to claim 1, characterized in that: In the laser etching step, when the conductive film is metallic silver or silver alloy PET conductive film, the laser etching equipment emits an infrared laser with a wavelength of 1064nm, a power of 8-12W, an etching speed of 20-30mm / s, and a focusing accuracy of ±5μm; when the conductive film is an ITO PET conductive film, the laser etching equipment emits an ultraviolet laser with a wavelength of 355nm, a power of 5-8W, an etching speed of 30-50mm / s, and a focusing accuracy of ±5μm.

8. The method for manufacturing an LED transparent display screen according to claim 1, characterized in that: In the LED chip die bonding step, a room temperature die bonding process is adopted. The LED chip (40) is fixedly installed at the intersection of the row electrode (311) and the cathode passage (312) by conductive silver paste. The die bonding temperature is 15-35℃, the pressure is 0.1-0.3MPa, and the thermal curing temperature is 150℃ for 30 minutes to ensure that the connection resistance between the LED chip (40) and the row electrode (311) and the cathode passage (312) is ≤0.1Ω.

9. The method for manufacturing an LED transparent display screen according to claim 1, characterized in that: In the integrated bonding and encapsulation step, the filler layer (51) is OCA adhesive, transparent silicone or transparent epoxy resin, and the thickness of the filler layer (51) is greater than the height of the LED chip (40), with a thickness of 0.15-0.30 mm; the protective film layer (52) is optical grade PET or transparent polycarbonate film, with a thickness of 50-150 μm, and the outer side is hardened to a hardness ≥4H and a light transmittance ≥92%.

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