Flexible ink screen production process

Abstract

The invention discloses a flexible ink screen production process, which comprises the following steps of: setting at least two symmetrically designed flexible substrate make-up appearances, and designing corresponding alignment Mark points; obtaining an electronic paper makeup appearance; the electronic paper is attached to the flexible substrate; carrying out plasma cleaning on the semi-finished product attached with the electronic paper; fitting and pressing a front protective film; iC bonding is carried out, UV reinforcing glue of the IC is dispensed, and UV curing is carried out; carrying out final product appearance cutting on the finished makeup semi-finished product, and then carrying out FPC bonding; and separating a single product through laser, dispensing UV glue on the connection of the FPC and the flexible substrate, and curing to obtain a finished product. The flexible ink screen production process is higher in production efficiency, better in waterproof performance, smaller in damage to a flexible substrate circuit, lower in manpower and material resource cost and shorter in production period.

Description

Technical Field

[0001] The present invention belongs to the field of flexible ink screens, and in particular relates to a flexible ink screen production process. Background Art

[0002] Flexible ink screen is a new type of display device using electronic ink technology. Its biggest feature is that the screen can be bent, folded or even curled without affecting the display effect. This screen technology combines the reading experience of traditional paper with the portability of modern electronic devices, and has become a major innovation in the field of display technology in recent years. Flexible ink screen has the characteristics of low power consumption, high contrast and clarity, high flexibility and durability, environmental protection and low energy consumption. It is widely used in e-book readers, smart tags, flexible billboards, wearable devices and smart home products, and has broad application prospects.

[0003] The production process of flexible ink screen mainly includes the following steps: (1) Material preparation: including electronic ink, substrate, conductive ink and packaging materials. Electronic ink is the core material. The substrate usually uses flexible materials such as polyimide film (PI). Conductive ink is used to prepare circuit lines, and packaging materials are used to protect circuits and display components. (2) Substrate production: The substrate needs to be cut into corresponding sizes, cleaned to remove oil and impurities, and then dried. Flexible substrates can be made of plastic or glass. Plastic substrates are lighter and suitable for scenes that require slight bending. (3) Coating electronic ink: Use spin coating, spraying or scraping to evenly coat the electronic ink on the substrate to form a thin film layer. Control the parameters during the coating process to ensure that the film layer is uniform in thickness, flat and free of bubbles. (4) Photolithography process: Coat photoresist on the substrate coated with electronic ink, and prepare circuit lines and display components through steps such as exposure, development and baking. (5) Etching and bonding: Use wet or dry etching to remove the unnecessary metal layer, then prepare the glass panel, apply glue and bond the substrate to the glass panel, and control the temperature, time and pressure during the bonding process. (6) Packaging: Seal the bonded ink screen to prevent moisture and impurities from entering, and apply silicone sealing material to improve sealing and impact resistance. Quality inspection: Perform visual inspection and performance testing to ensure that the performance of the ink screen meets the requirements, including display effect, response time, power consumption, etc.

[0004] As flexible ink screen products tend to be lighter, thinner and more flexible, the existing waterproof production process cannot meet the product's flexibility requirements. Summary of the invention

[0005] The purpose of the present invention is to provide a flexible ink screen production process with high production efficiency and good product waterproof effect in view of the above technical problems to be solved.

[0006] In order to achieve the above invention objectives, the present invention provides a flexible ink screen production process, which includes the following steps:

[0007] (1) Setting at least two symmetrically designed flexible substrate panel shapes and designing corresponding alignment mark points;

[0008] (2) obtaining the electronic paper layout shape;

[0009] (3) Laminating the electronic paper to the flexible substrate;

[0010] (4) Plasma cleaning of the semi-finished product with bonded electronic paper;

[0011] (5) Laminating and pressing the front protective film;

[0012] (6) IC bonding: Apply UV reinforcing glue to IC and perform UV curing;

[0013] (7) Cut the finished semi-finished product into the final product shape and then perform FPC bonding;

[0014] (8) The single-piece product is separated by laser, and then UV glue is applied to the connection points between the FPC and the flexible substrate and cured to obtain the finished product.

[0015] According to the process of the present invention, preferably, the electronic paper has a conducting hole.

[0016] According to the process of the present invention, preferably, in the step (2), the electronic paper through-hole and the outer shape are aligned and cut by the electronic paper CCD laser Mark: the whole page of electronic paper is cut, the cutting frequency of the outer shape is 3.5%, the cutting speed is 40mm / s, the laser pulse duty cycle is 14.2%, the minimum signal value is 3, the cutting frequency of the through-hole is 3.5%, the cutting speed is 30mm / s, the laser pulse duty cycle is 5.7%, the minimum signal value is 1.5, the passing temperature is 42°C, the pressure is 0.2Mpa, and the speed is 15mm / S.

[0017] According to the process of the present invention, preferably, in the step (3), the bonding conditions are set to room temperature, pressure 0.2 MPa, speed 15 mm / s, the Mark point of the flexible substrate and the edge of the electronic paper are searched for automatic capture and alignment, and the bonding of the electronic paper is started.

[0018] According to the process of the present invention, preferably, the plasma cleaning conditions are: time 10 min, power 4.0 RW, vacuum degree 15 Pa, nitrogen flow rate 400 Sccm, argon flow rate 800 Sccm, surface water drop angle ≤30°.

[0019] According to the process of the present invention, preferably, in the step (5), the laminating conditions are: room temperature, pressure 0.25 MPa, and speed 25 mm / S.

[0020] According to the process of the present invention, preferably, in the step (5), the pressing conditions are: temperature 105° C., pressure 0.3 MPa, and speed 1.5 m / min.

[0021] According to the process of the present invention, preferably, in the step (5), the high-pressure degassing conditions are: temperature 60° C., pressure 0.6 MPa, and time 1 hour.

[0022] According to the process of the present invention, preferably, in the step (7), the bonding conditions are a pressure of 30 N, a time of 7 seconds, and a temperature of 170°C.

[0023] On the other hand, the present invention also provides the application of the flexible electronic paper prepared according to the method in the field of electronic products or display screens.

[0024] The flexible ink screen production process of the present invention has significant advantages such as higher production efficiency, better waterproof performance, less damage to flexible substrate circuits, lower manpower and material costs, and shorter production cycle, and can be widely used in the fields of electronic products and display screens. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a flexible ink screen in the prior art.

[0026] Figure 2 yes Figure 1 Side view of the flexible ink screen.

[0027] Figure 3 It is a schematic diagram of the flexible substrate design of the flexible ink screen production process of the present invention.

[0028] Figure 4 It is a schematic diagram of the electronic paper platemaking structure of the flexible ink screen production process of the present invention.

[0029] Figure 5 It is a schematic diagram of the bonding of a flexible substrate and electronic paper in the flexible ink screen production process of the present invention.

[0030] Figure 6 It is a schematic diagram of the laminated front protective film of the flexible ink screen production process of the present invention.

[0031] Figure 7 It is a schematic diagram of the flexible ink screen production process of the present invention, which includes cutting the final product shape of the assembled semi-finished product and bonding the FPC.

[0032] Figure 8 It is a schematic structural cross-sectional diagram of the final product of the flexible ink screen production process of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings and specific examples. It should be understood that the following examples are only used to illustrate the present invention, rather than to limit the scope of the present invention.

[0034] Unless otherwise specified, the reagents, equipment, instruments, etc. used in the embodiments of the present invention are all existing products, which are known to those skilled in the art and can be obtained through commercial channels.

[0035] like Figure 1 and Figure 2 As shown, the product structure of the flexible ink screen in the prior art includes a front waterproof film, electronic paper and a flexible substrate. The electronic paper is located between the front waterproof film and the flexible substrate. The substrate is provided with an IC (integrated circuit) and an FPC (flexible printed circuit board), which are reinforced and fixed with reinforcing glue. The waterproof glue is cured at the product frame to enhance the waterproof effect.

[0036] The waterproofing process of existing flexible ink screen products usually uses glass to cover the upper waterproof film of electronic paper and then reinforce it with glue. The process path is as follows: flexible substrate design → product appearance glass cutting (single piece) → electronic paper cutting → electronic paper doping silver paste → electronic paper bonding → front protection bonding → degassing → IC bonding (bonding) → IC reinforcing glue → laser separation of flexible substrate → FPC bonding → FPC reinforcing glue → preliminary electrical testing → waterproof glue application → waterproof glue curing → finished product electrical testing. However, this process has the following defects: electronic paper bonding cannot be produced in a plate-like manner, and the production efficiency is low; the product is thick, fragile, and cannot be bent; it is difficult to apply glue on narrow-edge window products, and it is easy to overflow glue; the product frame is wide, and the reserved frame position for assembly is large; the glue mainly uses thermosetting glue, which has the limitations of being dry and brittle; the glue has poor bending resistance and is prone to delamination.

[0037] Different from the existing process, the production process route adopted by the present invention is as follows:

[0038] Flexible substrate design → panel shape cutting → panel electronic paper cutting → electronic paper bonding → plasma cleaning → front waterproof film bonding → lamination curing → positive pressure degassing → IC bonding → IC glue dispensing curing → product shape cutting → FPC bonding → laser separation of flexible substrate → FPC reinforcing glue dispensing → finished product electrical testing.

[0039] For the above process route, the specific description is as follows:

[0040] 1. Flexible substrate design

[0041] The single-chip design of the prior art is changed into a symmetrical design. That is, at least two symmetrically designed flexible substrate layouts are set, and corresponding alignment Mark points (reference points) are designed. Figure 3 As shown, eight flexible substrate shapes can be designed symmetrically, and each shape has a corresponding alignment mark point. This symmetrical design is conducive to improving the utilization rate of the electronic paper.

[0042] 2. Lamination of electronic paper and flexible substrate

[0043] Design the electronic paper layout shape. The electronic paper has a through hole. Use the electronic paper CCD laser mark to align the electronic paper through hole and shape, and then use the equipment with set parameters to fit them. Figure 4 As shown, there are four consecutive electronic paper layout shapes, the number of which is Figure 3 For example, the number of flexible substrates is twice the number of electronic papers, but the number is not limited thereto. Those skilled in the art may adjust the specific number according to actual conditions.

[0044] The specific operations are as follows:

[0045] (1) Place the entire electronic paper on the device platform and use a laser light point height tester to ensure that the laser light point is in the best position (the laser light point height tester has been factory-adjusted) and that all cutting points are within the cutting range.

[0046] The cutting parameters are as follows: the cutting frequency of the shape is 3.5%, the cutting speed is 40mm / s, the laser pulse duty cycle is 14.2%, and the minimum signal value is 3; the cutting frequency of the through hole is 3.5%, the cutting speed is 30mm / s, the laser pulse duty cycle is 5.7%, and the minimum signal value is 1.5. Confirm that the above parameters are correct before cutting.

[0047] (2) Set the temperature to 42°C, the pressure to 0.2 MPa, and the speed to 15 mm / s, and align the product shape with the electronic paper shape for lamination using the flip machine.

[0048] 3. Put silver paste into the silver paste hole, adjust the parameters of the bonding equipment (room temperature, pressure 0.2Mpa, speed 15mm / S), the equipment searches for the mark point of the flexible substrate and the edge of the electronic paper for automatic capture and alignment, and starts bonding the electronic paper. Figure 5 shown.

[0049] 4. Place the semi-finished product of the bonded electronic paper into the plasma chamber equipment, set the equipment parameters (time: 10min; power: 4.0RW; vacuum: 15Pa; nitrogen flow: 400Sccm; argon flow: 800Sccm) for plasma cleaning, and the surface water drop angle is ≤30° to increase the surface bonding force of the flexible substrate.

[0050] 5. Place the front protective film and the flexible substrate on the positioning baffle of the laminating machine, and then set the laminating equipment to the best parameters for lamination, and then press them through a high-temperature laminating machine (temperature: 105°C; pressure: 0.3Mpa; speed: 1.5m / min). Figure 6As shown, from top to bottom are the front protective film, electronic paper and flexible substrate.

[0051] The specific operations are as follows:

[0052] (1) A flexible, soft, ultra-thin (thickness 0.15 mm to 0.5 mm) high-adhesion (peel force ≥ 1500 gf / 25 mm) PET waterproof film is selected as the front protective film.

[0053] (2) The front protective film is laminated by adjusting the parameters of the laminating equipment (room temperature, pressure 0.25 MPa, speed 25 mm / s).

[0054] (3) Final lamination is performed by a roller laminator with the following parameters: temperature 105°C, pressure 0.3 MPa, speed 1.5 m / min.

[0055] (4) The lamination bubbles are squeezed out by setting the parameters of high-pressure degassing (temperature 60°C, pressure 0.6 MPa, time 1 hour) to ensure the visibility and flatness of the display area. The gap between the electronic paper and the flexible substrate is ≤0.3 mm.

[0056] 6. Write the bonding program through the COG (Chip On Glass) bonding equipment, and use the equipment bonding parameters (pressure 25N, time 7 seconds, temperature 165℃) and CCD alignment system to achieve simultaneous bonding (local pressure) of multiple ICs at one time, and then turn to bond the IC on the other side; then, apply UV (ultraviolet) reinforcement glue and UV curing to the IC.

[0057] 7. Cut the finished semi-finished product into the final product shape and then perform FPC bonding. Figure 7 shown.

[0058] The specific operations are as follows:

[0059] (1) Place the assembled flexible substrate on the equipment platform and use a laser light point height tester to ensure that the laser light point is in the best position. The product outline frame ensures that all cutting points are within the cutting range. Cutting parameters (outline half-cutting frequency 6%, cutting speed 30mm / s, laser pulse duty cycle 18%, minimum signal value 3) are confirmed to be correct before cutting.

[0060] (2) Write the alignment transfer program through the FOG bonding equipment, adjust the ACF (anisotropic conductive film) bonding and bonding parameters (pressure 30N, time 7 seconds, temperature 170°C) to automatically align and bond the FPC.

[0061] 8. Use laser to separate the single-piece product, then apply UV glue to the connection point between FPC and flexible substrate and cure it, reinforce the connection to prevent FPC from falling off, and finally conduct electrical testing of the finished product.

[0062] Figure 8 This is a schematic diagram of the finished structure of the flexible ink screen of the present invention. As shown in the figure, the front waterproof film covers the periphery of the electronic paper to form a good waterproof seal.

[0063] The new production process of the flexible ink screen according to the present invention has the following advantages:

[0064] (1) The new process is for batch production, while the old process is for single-piece production. The former is more than 500% more efficient than the latter;

[0065] (2) The old process ensures that the waterproof distance is 1.5mm, and the tolerance of the fitting needs to be considered, so a gap is left for the glue needle to come out (≥0.4mm), and the total distance of the two frames needs to be reserved for more than 1.9mm; the new process can achieve one-time lamination and final cutting of the finished product, and only the cutting tolerance needs to be considered.

[0066] (3) The product's priority protective film structure can enhance the force on the flexible substrate and reduce damage to the circuit of the flexible substrate when the flexible substrate and the glass base are separated by laser;

[0067] (4) The new flexible production process is the hot melt film method, which is superior to the dispensing curing method. It can save equipment and materials, reduce manpower, reduce personnel costs, shorten the production cycle, and achieve the goal of lean production.

Claims

1. A flexible ink screen production process, characterized in that: The following steps are involved: (1) Setting at least two symmetrically designed flexible substrate panel shapes and designing corresponding alignment mark points; (2) obtaining the electronic paper layout shape; (3) Laminating the electronic paper to the flexible substrate; (4) Plasma cleaning of the semi-finished product with bonded electronic paper; (5) Laminating and pressing the front protective film; (6) IC bonding: Apply UV reinforcing glue to IC and perform UV curing; (7) Cut the finished semi-finished product into the final product shape and then perform FPC bonding; (8) The single-piece product is separated by laser, and then UV glue is applied to the connection points between the FPC and the flexible substrate and cured to obtain the finished product.

2. The process according to claim 1, characterized in that The electronic paper has a conducting hole.

3. The process according to claim 2, characterized in that In the step (2), the electronic paper via holes and the outer shape are aligned and cut by the electronic paper CCD laser Mark: the entire electronic paper is cut, the cutting frequency of the outer shape is 3.5%, the cutting speed is 40 mm / s, the laser pulse duty cycle is 14.2%, the minimum signal value is 3, the cutting frequency of the through hole is 3.5%, the cutting speed is 30 mm / s, the laser pulse duty cycle is 5.7%, the minimum signal value is 1.5, the passing temperature is 42°C, the pressure is 0.2 MPa, and the speed is 15 mm / S.

4. The process according to claim 1, characterized in that In the step (3), the bonding conditions are set to room temperature, pressure 0.2 MPa, and speed 15 mm / s, and the Mark point of the flexible substrate and the edge of the electronic paper are searched for automatic capture and alignment, and the bonding of the electronic paper is started.

5. The process according to claim 1, characterized in that The plasma cleaning conditions are: time 10 min, power 4.0 RW, vacuum degree 15 Pa, nitrogen flow rate 400 Sccm, argon flow rate 800 Sccm, surface water drop angle ≤ 30°.

6. The process according to claim 1, characterized in that In the step (5), the laminating conditions are: room temperature, pressure 0.25 MPa, and speed 25 mm / s.

7. The process according to claim 1, characterized in that In the step (5), the pressing conditions are: temperature 105° C., pressure 0.3 MPa, and speed 1.5 m / min.

8. The process according to claim 1, characterized in that In the step (5), the high pressure degassing conditions are: temperature 60° C., pressure 0.6 MPa, and time 1 hour.

9. The process according to claim 1, characterized in that In the step (7), the bonding conditions are a pressure of 30 N, a time of 7 seconds, and a temperature of 170° C.

10. Application of the flexible electronic paper prepared by the process according to any one of claims 1 to 9 in the field of electronic products or display screens.

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