Preparation method of LED display screen

Abstract

The invention discloses a preparation method of an LED display screen, which comprises the following steps: placing LED lamp beads or wafers on a substrate, and preparing two parts of hydrogel with the same density; carrying out slotting operation on the first part of hydrogel, and transferring the LED lamp beads or wafers from the substrate to the surface of the slotted hydrogel; pouring the gallium-indium alloy from the periphery of the surface of the slotted hydrogel; transferring the first intermediate product to a low-temperature environment, performing a conduction test on the first intermediate product after a preset time, if the test passes, covering the surface of the first intermediate product with a second part of hydrogel, and adhering the upper and lower layers of hydrogel together to form a second intermediate product; and heating the second intermediate product, and stretching and cutting the heated second intermediate product to obtain the LED display screen. According to the invention, the prepared LED display screen can be stretched and bent at will, and the shape change can be taken into account while the distance can be adjusted at will.

Description

Technical Field

[0001] The invention relates to the technical field of LED display, and in particular to a method for preparing an LED display screen. Background Art

[0002] With the rapid development of science and technology, LED display screens, as an efficient, energy-saving and colorful display device, have been widely used in many fields such as commercial media, cultural performances, and news releases. However, traditional LED display screens have many limitations in terms of size expansion and cost-effectiveness. As we all know, the spacing between LED lamp beads in all LED display screens on the market has been determined when designing the circuit diagram, such as P1.2 and P1.5, which have a spacing of 1.2mm and 1.5mm. In actual applications, since the spacing between LED lamp beads in the existing LED display screens is fixed, the finished LED display screen can no longer change the spacing between the LED lamp beads, and the existing LED display screen has a poor bending effect, which affects the use effect of the LED display screen. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for preparing an LED display screen, so as to solve the problem that the spacing between LED lamp beads cannot be changed after the existing LED display screen is finished and the bending effect is poor.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing an LED display screen, which comprises the following steps:

[0005] S1: Place LED lamp beads or wafers on a substrate and prepare two hydrogels with the same density;

[0006] S2: performing a groove operation on the first hydrogel, and transferring the LED lamp beads or wafers from the substrate to the grooved surface of the hydrogel;

[0007] S3: pouring gallium-indium alloy from around the surface of the hydrogel after the grooves are opened to obtain a first intermediate product;

[0008] S4: transferring the first intermediate product to a low temperature environment, and performing a conduction test on the first intermediate product after a preset time, and if the test passes, executing step S5;

[0009] S5: covering the surface of the first intermediate product with a second portion of hydrogel, and gluing the upper and lower layers of hydrogel together to form a second intermediate product;

[0010] S6: heating the second intermediate product, and stretching and cutting the heated second intermediate product to obtain an LED display screen.

[0011] Furthermore, in the method for preparing the LED display screen of the present invention, in step S1, the arrangement spacing of the LED lamp beads or wafers on the substrate ranges from 0.001 to 0.01 mm, and the solder joints of the LED lamp beads or wafers face upward.

[0012] Furthermore, in the method for preparing the LED display screen of the present invention, in step S1, the step of preparing the hydrogel includes: copolymerizing poly(ethylene oxide) acrylate and polyethylene glycol diacrylate to obtain the hydrogel.

[0013] Furthermore, in the method for preparing the LED display screen of the present invention, the thickness of the first hydrogel is in the range of 2.0 mm±0.01 mm.

[0014] Furthermore, in the method for preparing the LED display screen of the present invention, in step S2, the grooving operation on the first hydrogel comprises:

[0015] Semi-grooving the hydrogel by laser to reduce the thickness of the hydrogel surface by 0.04 mm;

[0016] The laser is used to carve preset circuit grooves on the surface of the hydrogel after the thickness is reduced by 0.04 mm.

[0017] Furthermore, in the method for preparing the LED display screen of the present invention, the groove depth of the circuit groove is: 0.02±0.002mm.

[0018] Furthermore, in the method for preparing the LED display screen of the present invention, in step S4, the following steps are also included: if there are some areas that are not conducting, injecting gallium-indium alloy into the non-conducting areas, and after successful conduction, executing step S5.

[0019] Furthermore, in the method for preparing the LED display screen of the present invention, in step S4, the temperature range of the low temperature environment is 5-10° C., and the preset time is 5 minutes.

[0020] Furthermore, in the method for preparing the LED display screen of the present invention, in step S5, the upper and lower layers of hydrogel are bonded together, comprising the following steps: bonding the surfaces of the two hydrogels together by chemical crosslinking, physical adsorption or adhesive method.

[0021] Furthermore, in the method for preparing the LED display screen of the present invention, in step S6, the heated second intermediate product is stretched and cut, including:

[0022] After the gallium-indium alloy is liquefied, the second intermediate product is stretched multiple times along multiple preset directions; after the gallium-indium alloy is completely fluidized, excess hydrogel around the LED lamp beads or wafers is cut off.

[0023] The beneficial effect of the present invention is that PHEA-co-PEGDA-80 (PcP-80) hydrogel material is used as a carrier for carrying LED lamp beads or wafers, and on this basis, all components are connected and connected through gallium-indium alloy (EGaIn), so that the prepared LED display screen can be stretched and bent arbitrarily. Specifically, the stretching properties of the hydrogel and the fluidity of the gallium-indium alloy make it possible to stretch the LED lamp beads or wafer spacing in the LED display screen to the corresponding spacing according to demand, so that the spacing can be adjusted arbitrarily while taking into account the change of shape. It should be noted that the transformation of the spacing of LED lamp beads or wafers can be equal stretching transformation, equal proportional change, or both equal proportional and non-equal proportional changes, which are not limited here. At the same time, the stretching properties of the hydrogel (that is, good flexibility and stretchability) are used to enable the prepared LED display screen to achieve various degrees of bending. In addition, since the present invention uses gallium-indium alloy to replace the traditional connection method of copper wire and solder paste combination, the fluidity of the gallium-indium alloy is used to allow the broken wire or the part with unconducted gallium-indium alloy to automatically circulate and conduct, so that the product has automatic repairability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A flowchart of the steps of the method for preparing the LED display screen of the present invention in one embodiment;

[0025] Figure 2 The present invention is a flowchart of an exemplary application step of the method for preparing an LED display screen according to one embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0027] As we all know, the spacing between LED lamp beads in all LED display screens on the market has been determined when designing the circuit diagram. For example, the spacing of P1.2 and P1.5 is 1.2mm and 1.5mm. In actual applications, the production and delivery cycle of PCB boards for LED display screens will be about 30 days. Usually, companies need to prepare stocks during production and operation, such as batch purchase of key materials (such as PCB boards). This operation limits the capital flow of enterprises and also puts great pressure on enterprises. Because the purchased PCB boards become finished products, they cannot be mixed, such as the finished products of P1.2 and P1.5 cannot be mixed, resulting in a variety of finished products. Moreover, since the spacing between LED lamp beads in the existing LED display screens is fixed, the spacing between LED lamp beads cannot be changed after the finished LED display screen is finished. At the same time, some existing soft LED display screens can only be bent or folded, and cannot achieve extreme bending such as 360 degrees without dead angles, resulting in poor use of existing LED display screens. To this end, the present invention provides a method for preparing an LED display screen, which can be used to prepare LED display screens with various spacing requirements. It not only reduces the financial pressure of purchasing materials, but also can transform the single LED product into a diversified product. Moreover, the new product can change its form at will, which is more in line with current and future needs. At the same time, the method for preparing an LED display screen of the present invention can reduce the product defect rate, and during the preparation process, the product can automatically repair defective problems, reduce the difficulty of product maintenance, and improve product quality. Please refer to Figure 1 as well as Figure 2 The present invention provides a method for preparing an LED display screen, which comprises the following steps:

[0028] S1: Place LED lamp beads or wafers on a substrate and prepare two hydrogels with the same density;

[0029] S2: performing a groove operation on the first hydrogel, and transferring the LED lamp beads or wafers from the substrate to the grooved surface of the hydrogel;

[0030] S3: pouring gallium-indium alloy from around the surface of the hydrogel after the grooves are opened to obtain a first intermediate product;

[0031] S4: transferring the first intermediate product to a low temperature environment, and performing a conduction test on the first intermediate product after a preset time, and if the test passes, executing step S5;

[0032] S5: covering the surface of the first intermediate product with a second portion of hydrogel, and gluing the upper and lower layers of hydrogel together to form a second intermediate product;

[0033] S6: heating the second intermediate product, and stretching and cutting the heated second intermediate product to obtain an LED display screen.

[0034] From the above description, it can be seen that the beneficial effect of the present invention is: PHEA-co-PEGDA-80 (PcP-80) hydrogel material is used as a carrier for carrying LED lamp beads or wafers, and on this basis, all components are connected and connected through gallium-indium alloy (EGaIn), so that the prepared LED display can be stretched and bent arbitrarily. Specifically, the stretching properties of the hydrogel and the fluidity of the gallium-indium alloy allow the spacing of the LED lamp beads or wafers in the LED display to be stretched to the corresponding spacing according to demand, so that the spacing can be adjusted arbitrarily while taking into account the change of shape. At the same time, the stretching properties of the hydrogel (that is, good flexibility and stretchability) are used to enable the prepared LED display to achieve various degrees of bending. It should be noted that the maximum elongation of the hydrogel material is about 1500%. In addition, since the present invention uses gallium-indium alloy to replace the traditional connection method of copper wire and solder paste combination, the fluidity of the gallium-indium alloy is used to allow the broken wire or the part of the gallium-indium alloy that is not connected to flow automatically, so that the product has automatic repairability and avoids the breakage problem caused by the collision of the traditional PCB board design. In actual use, because the hydrogel has a ductility of 1500%+ and the gallium-indium alloy has fluidity and conductivity, the final product can be stretched without affecting its function. While stretching or bending, the arrangement spacing of the LED lamp beads or wafers fixed in the crystal glue can be changed, thereby achieving the function of adjusting the spacing of the LED display screen. It should be noted that the change of the spacing of the LED lamp beads or wafers can be equal stretching transformation, equal proportional change, or both equal proportional and non-equal proportional changes, etc., which are not limited here.

[0035] As described above, the present invention uses PHEA-co-PEGDA-80 (PcP-80) hydrogel material as a carrier for LED lamp beads or wafers, and then connects all components through gallium-indium alloy (EGaIn), thereby preparing an LED display screen that can be stretched and bent arbitrarily. Figure 2 , the above steps are elaborated in detail, and the specific operations are as follows:

[0036] Step (1): first place the LED lamp beads or wafers on the substrate. Specifically, place the required LED lamp beads or COB wafers on the substrate by mass transfer, with the spacing between each LED lamp bead or wafer being 0.001 to 0.01 mm. The LED lamp beads or wafers are temporarily fixed with the solder joints facing upward (i.e., facing downward).

[0037] Step (2): Prepare two hydrogels of the same density, wherein the preparation method of the hydrogel is as follows: poly(ethylene oxide) acrylate (PHEA) and polyethylene glycol diacrylate (PEGDA) are copolymerized to obtain PHEA-co-PEGDA-80 (PcP-80) hydrogel, which is then spread horizontally. The thickness of the first hydrogel prepared is 2.0 mm ± 0.01 mm.

[0038] Step (3): The first portion of the hydrogel is grooved, specifically: the hydrogel is semi-grooved by a laser to reduce the thickness of the entire hydrogel surface by 0.04mm; and a preset line groove is carved on the surface of the hydrogel after the thickness is reduced by 0.04mm by a laser, and the groove depth of the line groove is 0.02±0.002mm. In practical applications, the hydrogel in step (2) can be semi-grooved by a laser, that is, the entire hydrogel surface is scanned by a laser to reduce the thickness of the entire hydrogel surface by 0.04mm, and the hydrogel surface with a reduced thickness of 0.04mm is marked as surface A. It should be noted that the thickness of the hydrogel surface needs to remain consistent. Afterwards, a preset line groove (i.e., the required line design drawing) is carved on the surface of hydrogel A by a laser, and the depth of the line groove is 0.02±0.002mm. At the same time, line grooves for conducting with other hydrogels are reserved at the four corners of the hydrogel. It should be noted that the present invention only describes the preparation method of a single finished product, for example, the size of a single finished product is 150mm*100mm. In practical applications, line grooves for conducting with other hydrogels are reserved so that multiple finished products can be spliced ​​and used. That is, if the size of a single finished product cannot meet the large-size display requirements, multiple finished products can be connected in series to form a new generation of LED display screens.

[0039] Step (4): Transfer the LED lamp beads or wafers from the substrate to the surface of the hydrogel after the grooves are cut. In practical applications, the LED lamp beads or wafers temporarily fixed in step (1) can be transferred from the substrate to the surface of the first hydrogel after the grooves are cut in step (3) by mass transfer technology. Note that the surface area of ​​the first hydrogel must be larger than the area of ​​the substrate to transfer the lamp beads. When transferring the LED lamp beads or wafers to the surface of the hydrogel after the grooves are cut, they need to be pressed tightly to prevent the LED lamp beads or wafers from moving or offsetting.

[0040] Step (5): Pour the gallium-indium alloy from all sides of the surface of the hydrogel after the groove is opened to obtain the first intermediate product, and the amount of the injected gallium-indium alloy (EGaIn) reaches a height of 0.02mm covering the surface of the hydrogel. Specifically: After the LED lamp beads or wafers are fixed, the gallium-indium alloy (EGaIn) is poured from all sides of the hydrogel surface through the equipment primer pouring method. Note that there should be no LED lamp beads or wafers within 0.05mm around the pouring point to avoid the movement of the surrounding LED lamp beads or wafers when the gallium-indium alloy (EGaIn) liquid is poured. It should be noted that the total amount of pouring depends on the surface area of ​​the hydrogel, and the amount of the injected gallium-indium alloy (EGaIn) reaches a height of 0.02mm covering the surface of the hydrogel. In practical applications, the gallium-indium alloy needs to be poured into the circuit groove on the surface of the hydrogel, and a layer of gallium-indium alloy with a thickness of 0.02mm is covered where the LED lamp beads or wafers are welded at the bottom. From the above description, it can be seen that the traditional connection method of copper wire and solder paste is replaced by gallium indium alloy (EGaIn), and the fluidity of gallium indium alloy (EGaIn) is used to make the broken wire or the non-conductive part of gallium indium alloy (EGaIn) automatically flow and conduct, so that the product has the ability of automatic repair and avoids the breakage problem caused by collision in traditional PCB board design.

[0041] Step (6): Transfer the first intermediate product to a low temperature environment, and perform a conduction test on the first intermediate product after a preset time. If there are some areas that are not conductive, inject the gallium-indium alloy into the non-conductive area to further conduct the non-conductive area. In practical applications, the product in step (5) is transferred and placed in a device at 5 to 10°C. After 5 minutes, the gallium-indium alloy (EGaIn) is transformed into a solid state. At this time, the solder joint position at the bottom of the LED lamp bead or the wafer is connected to the solid gallium-indium alloy (EGaIn), that is, the bottom link of the fixed lamp bead is connected. In practical applications, at this time, it can be tested to determine whether it is conductive. If the test shows that some areas are not conductive, the gallium-indium alloy (EGaIn) can be designed to be conductive, that is, the gallium-indium alloy is injected into the non-conductive area. Because there is a phenomenon that the gallium-indium alloy injected is too little during the production process, resulting in a short circuit in some areas and cannot be used normally, the gallium-indium alloy is actually used to supplement the less or missing parts. Note that the melting point of gallium indium alloy (EGaIn) is about 15.7℃, so the temperature in the equipment must be lower than the melting point of gallium indium alloy (EGaIn), if it is lower than 15℃, the static temperature is inversely proportional to the time, that is, the lower the temperature, the shorter the time, and the temperature must not be lower than 0℃ to avoid abnormal problems such as water vapor in static or subsequent processes, that is, the ambient temperature must be lower than the melting point of gallium indium alloy (EGaIn) of about 15.7℃, and there must be no water vapor or mist in the environment. From the above description, it can be seen that by utilizing the fluidity of gallium indium alloy (EGaIn), the part of gallium indium alloy (EGaIn) that is not conducting can be automatically circulated and conducted, and the product can automatically repair the defective problems during the preparation process, reduce the difficulty of product maintenance, and improve product quality.

[0042] Step (7): Cover the second portion of the hydrogel on the surface of the first intermediate product, and glue the upper and lower layers of the hydrogel together to form the second intermediate product. In practical applications, the surface of the first intermediate product in step (6) is covered with a hydrogel of the same density as in step (2) (with the same mixing ratio), and the surface-covered hydrogel area must be larger than the fixed area of ​​the LED lamp beads or wafers, so that there is no excess on the surface during subsequent cutting. In addition, the thickness of the second portion of the hydrogel covered on the surface of the first intermediate product must exceed the surface of the LED lamp beads or wafers by more than 0.5 mm. It should be noted that when gluing the upper and lower layers of the hydrogel together, a corresponding method can be selected according to actual conditions for gluing, such as chemical cross-linking, physical adsorption, and adhesive methods can be used to glue the two hydrogel surfaces together, which is not limited here. From the above description, it can be seen that the second portion of the hydrogel is covered on the LED lamp beads or wafers, and the second portion of the hydrogel is mainly used for surface sealing. In addition to protecting the LED lamp beads or wafers, it can also prevent oxidation or moisture.

[0043] Step (8): Heat the second intermediate product, and stretch and cut the heated second intermediate product to obtain an LED display screen. Specifically: Heat the second intermediate product, and after the gallium-indium alloy is liquefied, stretch the second intermediate product multiple times along multiple preset directions; after the gallium-indium alloy is completely fluidized, cut off the excess hydrogel outside the 0.05mm range around the LED lamp bead or wafer. In practical applications, the second intermediate product is placed in a heating device, and the temperature gradually rises. At this time, the gallium-indium alloy (EGaIn) in the hydrogel changes from solid to liquid. Continue to heat to 50-60°C, so that the gallium-indium alloy (EGaIn) can flow fully. At this time, the viscosity of the upper and lower hydrogels is more solid. On this basis, the excess hydrogel outside the 0.05mm range around the LED lamp bead or wafer is cut off by laser technology. Note that the LED lamp bead or wafer should not be touched when cutting the hydrogel. It should be noted that during the process of heating the product, after the gallium indium alloy (EGaIn) is liquefied, it is stretched several times in four directions, and after the gallium indium alloy (EGaIn) is completely fluidized, the excess hydrogel around it is cut off.

[0044] In summary, the LED display screen preparation method provided by the present invention: (1) can be used to prepare LED display screens with various spacing requirements, which not only reduces the financial pressure of purchasing materials, but also can transform the singleness of LED products into diversified products, and the new products can change their shapes arbitrarily, which is more in line with current and future needs. (2) The LED display screen preparation method of the present invention can reduce the product defect rate, and the product can automatically repair the defective problems during the preparation process, reduce the difficulty of product maintenance, and improve product quality. (3) The preparation method of the present invention can reduce the high temperature requirements of the production process. The temperature in the process flow can be controlled within 100 degrees Celsius, and some steps can also be completed at room temperature, further realizing energy saving and cost reduction in production. (4) The prepared finished product can use the stretching properties of the hydrogel and the fluidity of the gallium indium alloy (EGaIn) to allow the spacing of the LED lamp beads or wafers in the LED display screen to be stretched to the corresponding spacing according to the needs, so that the spacing can be arbitrarily adjusted while taking into account the change of shape, and it can also be attached to the surface of the object in a diversified manner. The maximum stretching rate of the PHEA-co-PEGDA-80 (PcP-80) hydrogel material is about 1500%. (5) It has automatic repairability. The present invention uses gallium-indium alloy (EGaIn) to replace the traditional connection method of copper wire and solder paste combination. Through the fluidity of gallium-indium alloy (EGaIn), the broken wire or the non-conductive part of gallium-indium alloy (EGaIn) can be automatically circulated and connected, thereby realizing the product's automatic repair capability and avoiding the breakage problem caused by collision in traditional PCB board design.

[0045] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing an LED display screen, characterized in that: The following steps are involved: S1: Place LED lamp beads or wafers on a substrate and prepare two hydrogels with the same density; S2: performing a groove operation on the first hydrogel, and transferring the LED lamp beads or wafers from the substrate to the grooved surface of the hydrogel; S3: pouring gallium-indium alloy from around the surface of the hydrogel after the grooves are opened to obtain a first intermediate product; S4: transferring the first intermediate product to a low temperature environment, and performing a conduction test on the first intermediate product after a preset time, and if the test passes, executing step S5; S5: covering the surface of the first intermediate product with a second portion of hydrogel, and gluing the upper and lower layers of hydrogel together to form a second intermediate product; S6: heating the second intermediate product, and stretching and cutting the heated second intermediate product to obtain an LED display screen.

2. The method for preparing an LED display screen according to claim 1, characterized in that: In step S1, the LED lamp beads or wafers are arranged at a spacing range of 0.001 to 0.01 mm on the substrate, and the solder joints of the LED lamp beads or wafers face upward.

3. The method for preparing an LED display screen according to claim 1, characterized in that: In step S1, the preparation step of the hydrogel includes: copolymerizing poly(ethylene oxide) acrylate and polyethylene glycol diacrylate to obtain a hydrogel.

4. The method for preparing an LED display screen according to claim 1, characterized in that: The thickness of the first hydrogel is in the range of 2.0 mm ± 0.01 mm.

5. The method for preparing an LED display screen according to claim 1, characterized in that: In step S2, the grooving operation is performed on the first hydrogel, comprising: Semi-grooving the hydrogel by laser to reduce the thickness of the hydrogel surface by 0.04 mm; The laser is used to carve preset circuit grooves on the surface of the hydrogel after the thickness is reduced by 0.04 mm.

6. The method for preparing an LED display screen according to claim 5, characterized in that: The groove depth of the line groove is: 0.02±0.002mm.

7. The method for preparing an LED display screen according to claim 1, characterized in that: In step S4, the following steps are also included: if there are some areas that are not conducting, then the gallium-indium alloy is injected into the non-conducting areas, and after successful conduction, step S5 is performed.

8. The method for preparing an LED display screen according to claim 1, characterized in that: In step S4, the temperature range of the low temperature environment is 5-10°C, and the preset time is 5 minutes.

9. The method for preparing an LED display screen according to claim 1, characterized in that: In step S5, the upper and lower layers of hydrogel are bonded together, which includes the following steps: bonding the surfaces of the two hydrogels together by chemical cross-linking, physical adsorption or adhesive method.

10. The method for preparing an LED display screen according to claim 1, characterized in that: In step S6, the heated second intermediate product is stretched and cut, including: After the gallium-indium alloy is liquefied, the second intermediate product is stretched multiple times along multiple preset directions; after the gallium-indium alloy is completely fluidized, excess hydrogel around the LED lamp bead or wafer is cut off.

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