A display substrate photoresist stripping apparatus

Abstract

This utility model relates to a photoresist stripping device for display substrates. The device includes at least one stripping unit, which is connected in series. Each stripping unit includes a main tank and an upper tank. The upper tank includes an outer tank and an inner tank. The inner tank is located inside the outer tank. The outlet of the main tank is connected to the inlet of the inner tank via a bath construction pipeline. The outlet of the inner tank is connected to the main tank via a circulation pipeline. The main tank is used to store photoresist stripping solution. An ultrasonic generator is located at the bottom of the inner tank. The inner tank is equipped with a spraying assembly and a conveying assembly. The conveying assembly is located inside the inner tank and above the ultrasonic generator. The spraying assembly is located above the conveying assembly. The spraying assembly is connected to the outlet of the main tank via a spraying pipeline. This utility model utilizes a spraying assembly to rapidly remove the photoresist from the glass substrate and into the main tank while ensuring uniform circulation of the solution.

Description

Technical Field

[0001] This utility model relates to the field of display technology, and in particular to a photoresist stripping device for display substrates. Background Technology

[0002] In the manufacturing process of flat panel displays (such as OLED or LCD screens), the patterning process, such as the array process, requires the use of photoresist as a mask. After the entire pattern is created, the photoresist needs to be peeled off to proceed to the next process.

[0003] With the increasing demands for display precision in recent years, such as the widespread application of technologies like AR, VR, or "retina displays," the pixels or lines on the display surface are becoming increasingly fine, and the circuit structure is becoming increasingly complex. Consequently, the requirements for the entire display manufacturing process are also becoming more stringent, as are the yield requirements.

[0004] Photoresist stripping is the final step in the entire patterning process. After photoresist coating, exposure, development, etching, and photoresist stripping, the product will proceed to the next process step. Whether the photoresist is completely removed directly affects the product yield. In fine-scale displays, the linewidth and spacing of the surface lines are even close to the sub-micron level. Under such fine-dimensional conditions, how to completely remove the photoresist without damaging the film layer covered by the original photoresist is a key focus of display manufacturing process research and development.

[0005] CN103995441B and CN111142342A propose similar photoresist stripping methods, namely, using high-pressure spraying to dissolve and remove the photoresist on the surface of the display substrate using a photoresist stripping solution. However, when dealing with fine lines, due to the extremely precise line width and spacing, and surface tension, the photoresist stripping solution cannot penetrate deep into the line structure to completely remove photoresist in dead corners and irregularly shaped locations. Although CN111142342A improved the spraying system compared to CN103995441B, its fundamental structural principle is exactly the same, and it cannot completely solve the problem. Currently, the mainstream solution in the industry is to use multiple sprays and repeated rinsing to achieve the removal purpose, but this solution greatly reduces the operating rate of the production line, increases operating costs, and still cannot completely remove photoresist within extremely fine structures.

[0006] CN107665810A proposes a method for removing photoresist from micro-line traces. The method involves statically and vertically arranging the wafer in a container filled with stripping fluid, then placing the container in a water bath and using a process time of 6 to 8 hours to remove the photoresist. Although this solution can completely remove the photoresist, its efficiency is relatively low and it is not suitable for applications of large-size display panels.

[0007] CN113721430B proposes a novel solution that utilizes the high-speed rotation of the product and employs a complex process involving ultrasonic waves, spraying, and rotation to remove the photoresist. This solution can completely remove the photoresist, but it is more suitable for smaller products (such as wafers) and is not applicable to large-sized display substrates.

[0008] The existing mainstream technologies use high-pressure spraying to remove photoresist. However, due to the surface tension between the chemical solution and the product, the spraying method cannot efficiently penetrate the chemical solution into the microstructure of the circuit to completely dissolve and remove the photoresist. The mainstream method of repeated spraying over extended periods reduces equipment uptime and still cannot completely remove photoresist from particularly fine structures. Therefore, a new solution is needed to address this problem. Summary of the Invention

[0009] To solve the above-mentioned technical problems, this utility model provides a display substrate photoresist stripping device, which effectively solves the technical problem that the existing high-pressure spraying method cannot completely remove the photoresist.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] This invention provides a photoresist stripping device for a display substrate, the device comprising at least one stripping unit; the stripping units are connected in series.

[0012] The stripping unit includes a main groove and an upper groove; the upper groove includes an outer groove and an inner groove; the inner groove is disposed inside the outer groove.

[0013] The outlet of the main tank is connected to the inlet of the inner tank via a bath construction pipeline; the outlet of the inner tank is connected to the main tank via a circulation pipeline; the main tank is used to store photoresist stripping solution.

[0014] An ultrasonic generating component is provided at the bottom of the inner tank; a spraying component and a conveying component are provided in the inner tank; the conveying component is located inside the inner tank and above the ultrasonic generating component; the spraying component is located above the conveying component; the spraying component is connected to the liquid outlet of the main tank through a spraying pipe.

[0015] This invention addresses the large size characteristics of flat panel display substrates by employing a horizontal transport method for the manufacturing process. The flat panel display substrate is horizontally transported into the process area for immersion. Ultrasonic vibration removes the photoresist within the microstructure. A spray assembly ensures uniform circulation of the solution, enabling the photoresist to be quickly removed from the substrate and transferred to the main tank. This enhances the photoresist removal capability and significantly improves product yield.

[0016] It should be noted that, depending on the process time and production capacity requirements, the stripping unit of this utility model can be connected in series with two or more units. The series stripping units can be designed to deliver the medicine step by step forward. Under the condition of multiple stripping units connected in series, a medicine concentration gradient will be formed between multiple stripping units. That is, the later the stripping unit is, the higher the purity and concentration of the medicine. Under this condition, the amount of medicine used can be further saved, which is more conducive to large-scale industrial production.

[0017] As a preferred technical solution of this utility model, the bathing pipeline is equipped with a pump device, a regulating valve and a flow detection component.

[0018] As a preferred technical solution of this utility model, the spray pipeline is equipped with a pump device, a regulating valve and a flow detection component.

[0019] As a preferred technical solution of this utility model, the inner tank is provided with a product inlet and a product outlet; the product inlet and product outlet are provided with bath baffles.

[0020] In this invention, the bath baffle has a lifting function. Before the product enters the inner tank, the bath baffle is lowered to its lowest position, at which point the liquid level is lower than the product. After the product enters the inner tank, the bath baffle is raised, and the liquid level rises rapidly until the product is submerged. The photoresist stripping liquid overflows from the highest position of the bath baffle and returns to the main tank through the return pipe, thus achieving circulation.

[0021] As a preferred technical solution of this utility model, the main tank is also provided with a fixed-flow pipeline and a filtration device.

[0022] As a preferred technical solution of this utility model, the outer tank is provided with a product inlet and a product outlet; the product inlet and product outlet are provided with air knife cleaning components.

[0023] As a preferred technical solution of this utility model, the device further includes an air intake device; the air intake device is connected to the air knife cleaning assembly of the outer tank.

[0024] As a preferred embodiment of this invention, the ultrasonic generating component includes an ultrasonic transducer plate.

[0025] As a preferred technical solution of this utility model, the liquid outlet of the outer tank is connected to the main tank through a return pipeline.

[0026] As a preferred embodiment of this invention, the device further includes a transmission unit; the transmission unit is used to transport the product to be processed.

[0027] This utility model provides a method for removing photoresist from a display substrate. The method is performed using the aforementioned display substrate photoresist removal equipment and includes the following steps:

[0028] The photoresist stripping solution in the main tank enters the inner tank of the stripping unit through the bath construction pipeline and the spray pipeline.

[0029] The display substrate to be processed is conveyed to the inner tank of the stripping unit, and the surface of the display substrate to be processed is immersed in photoresist stripping liquid. The ultrasonic generator is activated to apply ultrasonic waves to the non-processed surface of the display substrate. The display substrate to be processed is moved back and forth using the conveying component, and the spraying component is activated to allow the stripped photoresist to quickly overflow into the outer tank. The photoresist stripping liquid in the inner tank enters the main tank through the circulation pipeline, forming a circulating spray of photoresist stripping liquid.

[0030] This invention employs a scheme where the surface of the display substrate to be processed faces away from the ultrasonic functional surface, significantly reducing the impact of ultrasonic peak values ​​on the film structure. By utilizing the energy absorption of the display substrate, the difference between the peak and valley values ​​of the sound pressure when the ultrasonic wave penetrates the display substrate and acts on the process film layer is greatly reduced. Furthermore, by adjusting the appropriate sound pressure threshold or energy threshold of the ultrasonic wave, the intensity of the ultrasonic wave acting on the film layer is made more balanced and the distribution is more uniform, greatly reducing the risk of damage to the film layer. This avoids the risk of irreversible damage to the film layer caused by the direct action of traditional ultrasonic waves on the surface of the display substrate to be processed.

[0031] Preferably, the power of the ultrasonic generating component is 80kHz to 200kHz, such as 80kHz, 100kHz, 120kHz, 140kHz, 160kHz, 180kHz, 200kHz, etc., but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0032] Preferably, after the photoresist is stripped, an air knife cleaning assembly is used to remove the residual photoresist stripping liquid, and the display substrate proceeds to the next process; the next process includes a cleaning process.

[0033] Preferably, the method further includes the photoresist being rapidly overflowed into the outer tank, then entering the main tank of the stripping unit through the return pipeline, and after being filtered by the filter device, returning to the inner tank.

[0034] Compared with the prior art, the present invention has at least the following beneficial effects:

[0035] (1) The equipment of this utility model adopts a horizontal transmission method for the process. The flat panel display substrate is horizontally transported into the process area for immersion. The photoresist in the microstructure is removed by ultrasonic vibration. The spray component is used to quickly remove the stripped photoresist from the substrate body and enter the main tank under the condition of ensuring uniform circulation of the solution. This improves the photoresist stripping ability and greatly improves the product yield.

[0036] (2) The device of this utility model is equipped with an inner tank and an outer tank. The outlet of the inner tank is connected to the main tank through a circulation pipeline, and the outer tank is connected to the main tank through a return pipeline. This allows the photoresist stripping liquid to be fully replaced and flowed. The stripped photoresist quickly detaches from the substrate surface and flows back to the main tank. After filtration in the main tank, the fresh liquid returns to the upper tank, thus eliminating the influence of photoresist sticking back to the product surface.

[0037] (3) The device of this utility model adopts the process scheme of ultrasonic back action, and uses the substrate body to absorb energy, which greatly reduces the difference between the peak and trough of ultrasonic waves and eliminates the damage of ultrasonic waves to the fragile process film layer; in addition, the cavitation effect of ultrasonic waves is used to overcome the surface tension of the liquid, so that the liquid can directly act on the photoresist in the microstructure and peel it off, which is highly efficient. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of a display substrate photoresist stripping device provided by this utility model.

[0039] Among them, 1-main tank, 2-upper tank, 3-outer tank, 4-inner tank, 5-bath pipe, 6-circulation pipe, 7-ultrasonic generating component, 8-spray component, 9-transport component, 10-spray pipe, 11-pump device, 12-regulating valve, 13-air knife cleaning component, 14-air inlet device, 15-return pipe, 16-flow detection component, 17-constant discharge pipe, 18-bath baffle. Detailed Implementation

[0040] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of this utility model and do not represent or limit the scope of protection of this utility model. The scope of protection of this utility model is determined by the claims.

[0041] Example 1

[0042] This embodiment provides a photoresist stripping device for a display substrate, the device including at least one stripping unit; the stripping units are connected in series.

[0043] The stripping unit includes a main groove 1 and an upper groove 2; the upper groove 2 includes an outer groove 3 and an inner groove 4; the inner groove 4 is disposed inside the outer groove 3;

[0044] The outlet of the main tank 1 is connected to the inlet of the inner tank 4 via a bath construction pipe 5; the outlet of the inner tank 4 is connected to the main tank 1 via a circulation pipe 6; the main tank 1 is used to store photoresist stripping solution.

[0045] An ultrasonic generating component 7 is provided at the bottom of the inner tank 4; a spraying component 8 and a conveying component 9 are provided in the inner tank 4; the conveying component 9 is located inside the inner tank 4 and above the ultrasonic generating component 7; the spraying component 8 is located above the conveying component 9; the spraying component 8 is connected to the liquid outlet of the main tank 1 through a spraying pipe 10.

[0046] The bathing pipeline 5 is equipped with a pump device 11, a regulating valve 12, and a flow detection component 16; the spray pipeline 10 is equipped with a pump device 11, a regulating valve 12, and a flow detection component 16.

[0047] The inner tank 4 is provided with a product inlet and a product outlet; the product inlet and product outlet are provided with a building bath baffle 18;

[0048] The bath baffle 18 has a lifting function. Before the product enters the inner tank 4, the bath baffle 18 is lowered to its lowest position, at which point the liquid level is lower than the product. After the product enters the inner tank 4, the bath baffle 18 is raised, and the liquid level rises rapidly until the product is submerged. The photoresist stripping liquid overflows from the highest position of the bath baffle 18 and returns to the main tank 1 through the return pipe 15, thus achieving circulation.

[0049] The main tank 1 is also equipped with a fixed-flow pipeline 17 and a filter device;

[0050] The outer tank 3 is provided with a product inlet and a product outlet; the product inlet and product outlet are provided with an air knife cleaning assembly 13; the equipment also includes an air intake device 14; the air intake device 14 is connected to the air knife cleaning assembly 13 of the outer tank 3;

[0051] The ultrasonic generating component 7 includes an ultrasonic transducer plate; the outlet of the outer tank 3 is connected to the main tank 1 through a return pipe 15; the device also includes a transmission unit; the transmission unit is used to transport the product to be processed.

[0052] Comparative Example 1

[0053] This comparative example provides a photoresist stripping device for a display substrate. The only difference from Example 1 is that the ultrasonic generator component is omitted, while all other devices and equipment are the same as in Example 1.

[0054] Comparative Example 2

[0055] This comparative example provides a photoresist stripping device for a display substrate. The only difference from Example 1 is that the spray assembly is omitted, while all other devices and equipment are the same as in Example 1.

[0056] Application Example 1

[0057] This application example provides a method for photoresist stripping of a display substrate. The method is performed using the photoresist stripping equipment for the display substrate described in Example 1. The method includes the following steps: the photoresist stripping liquid in the main tank 1 enters the inner tank 4 of the stripping unit through the bath construction pipeline 5 and the spray pipeline 10.

[0058] The display substrate to be processed is conveyed to the inner tank 4 of the stripping unit, and the surface to be processed of the display substrate is immersed in the photoresist stripping liquid. The ultrasonic generator 7 is turned on to apply ultrasonic waves to the non-processed surface of the display substrate. The display substrate to be processed is moved back and forth using the conveying component 9, and the spraying component 8 is turned on to make the stripped photoresist quickly overflow into the outer tank 3. The photoresist stripping liquid in the inner tank 4 enters the main tank 1 through the circulation pipe 6 to form a circulating spray of photoresist stripping liquid.

[0059] The ultrasonic generator 7 has a power of 80kHz; after the photoresist is stripped, the air knife cleaning assembly 13 is used to remove the residual photoresist stripping liquid, and the display substrate enters the next process; the next process includes a cleaning process; the method also includes that the stripped photoresist quickly overflows into the outer tank 3, enters the main tank 1 of the stripping unit through the return pipe 15, and returns to the inner tank 4 after being filtered by the filter device.

[0060] Comparative Application Example 1

[0061] This comparative application example provides a method for photoresist stripping of a display substrate. The only difference between this method and Application Example 1 is that the method is performed using the photoresist stripping equipment described in Comparative Example 1. All other steps and operating conditions are the same as in Application Example 1.

[0062] Comparative Application Example 2

[0063] This comparative application example provides a method for removing photoresist from a display substrate. The only difference between this method and Application Example 1 is that the method uses the display substrate photoresist removal equipment described in Comparative Example 2. All other steps and operating conditions are the same as in Application Example 1.

[0064] Performance testing

[0065] The photoresist residue rates of the display substrates in Application Example 1 and Comparative Application Examples 1-2 after peeling are shown in Table 1.

[0066] Table 1

[0067] Application Example 1 No residue, no damage Comparative Application Example 1 0.2～0.5％ Comparative Application Example 2 <0.1％

[0068] Performance Analysis

[0069] (1) As can be seen from Application Example 1 and Comparative Application Example 1, this utility model uses ultrasonic waves to peel off the photoresist from the substrate to be processed. The scheme of using the process side facing away from the ultrasonic functional side greatly reduces the impact of the ultrasonic peak on the film structure, making the ultrasonic intensity acting on the film layer more balanced and more uniformly distributed, greatly reducing the risk of damage to the film layer and improving the photoresist peeling effect of the display substrate.

[0070] (2) As can be seen from Application Example 1 and Comparative Application Example 2, this utility model utilizes a spray assembly to achieve the function of quickly removing the photoresist from the glass body and entering the main tank while ensuring that the photoresist stripping liquid circulates evenly between the main tank and the inner tank. This improves the photoresist stripping ability and greatly enhances the product yield.

[0071] In summary, this invention provides a photoresist stripping device for display substrates. By combining ultrasonic waves with a spray assembly, it can remove photoresist from the microstructure of the display substrate. Furthermore, by utilizing the circulation channel between the main tank and the upper tank, it ensures uniform circulation of the photoresist stripping solution while preventing photoresist from re-adhering to the display substrate surface. This photoresist stripping device effectively removes photoresist from the circuit microstructure, reduces process time, and significantly improves yield.

[0072] The applicant declares that the above description is only a specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model fall within the protection and disclosure scope of the present utility model.

Claims

1. A photoresist stripping device for display substrates, characterized in that, The device includes at least one stripping unit; the stripping units are connected in series. The stripping unit includes a main groove and an upper groove; the upper groove includes an outer groove and an inner groove; the inner groove is disposed inside the outer groove. The outlet of the main tank is connected to the inlet of the inner tank via a bath construction pipeline; the outlet of the inner tank is connected to the main tank via a circulation pipeline; the main tank is used to store photoresist stripping solution. An ultrasonic generating component is provided at the bottom of the inner tank; a spraying component and a conveying component are provided in the inner tank; the conveying component is located inside the inner tank and above the ultrasonic generating component; the spraying component is located above the conveying component; the spraying component is connected to the liquid outlet of the main tank through a spraying pipe.

2. The device according to claim 1, characterized in that, The building bath pipeline is equipped with a pump device, a regulating valve, and a flow detection component.

3. The device according to claim 1 or 2, characterized in that, The spray pipeline is equipped with a pump device, a regulating valve, and a flow detection component.

4. The device according to claim 1, characterized in that, The inner tank is provided with a product inlet and a product outlet; the product inlet and product outlet are provided with bath baffles.

5. The device according to claim 1, characterized in that, The main tank is also equipped with fixed-flow pipelines and a filtration device.

6. The device according to claim 1, characterized in that, The outer tank is provided with a product inlet and a product outlet; the product inlet and product outlet are provided with air knife cleaning components.

7. The device according to claim 6, characterized in that, The device also includes an air intake device; the air intake device is connected to the air knife cleaning assembly of the outer tank.

8. The device according to claim 1, characterized in that, The ultrasonic generating component includes an ultrasonic transducer plate.

9. The device according to claim 1, characterized in that, The outlet of the outer tank is connected to the main tank via a return pipeline.

10. The device according to claim 1, characterized in that, The device also includes a transmission unit; the transmission unit is used to transport the products to be processed.

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