Cleaning system for photoresist coating die head of mask

Abstract

The invention belongs to the technical field of coating die head cleaning, and particularly discloses a cleaning system of a mask photoresist coating die head, which comprises a rack and a cross beam, the cross beam is connected with the rack, the cross beam is connected with a scraper, a cleaning liquid medicine tank is arranged below the scraper, a cleaning agent is filled in the cleaning liquid medicine tank, and the cleaning agent is connected with the cross beam. The distance between the liquid level of the cleaning agent and the photoresist outlet of the scraper is 1-5mm, and the cleaning agent can dissolve and clean the photoresist on the scraper after being volatilized. According to the invention, the problem that the glue outlet of the scraper is blocked can be solved, and meanwhile, the quality problem caused by generation of gluing bubbles and difference of photoresist components is improved.

Description

Technical Field

[0001] The invention relates to the technical field of coating die cleaning, in particular to a cleaning system for a mask photoresist coating die. Background Art

[0002] The mask, also known as the photomask, is made of quartz glass as the substrate. First, a layer of metal chromium is plated on the quartz glass substrate, and then photoresist is coated on the chromium layer to make it a photosensitive material. The designed circuit pattern is exposed to the photoresist through an electronic laser device. The exposed area is developed and etched on the metal chromium to form the circuit pattern, becoming a photomask master similar to an exposed film.

[0003] In the mask production process, independent control of the mask blank photoresist coating process is particularly important. Currently, the common photoresist coating methods in the industry include spin coating, slit coating, and blade coating, each of which has its most suitable application.

[0004] In the mask manufacturing field, the Slit+Spin mode is often used for photoresist coating. Its advantage is that it can take into account the characteristics of slit coating to save photoresist and good control of spin coating film thickness uniformity. Figure 4 As shown, the coating operation sequence is: ① Slit coating: Use a scraper with an opening of 100 microns to apply a layer of photoresist on the chromium surface of the raw material to be coated; ② Spin coating: The photoresist on the surface of the raw material is rotated and accelerated to evenly disperse the photoresist on the surface, thereby improving the uniformity of the film thickness; ③ Baking: The coated raw material is sent to the heating chamber for baking to evaporate the solvent in the photoresist.

[0005] In the Slit coating process, the core component is the Slit scraper, and its structure is shown in the attached figure. Figure 1 As shown, the main structure consists of two left and right pillars supporting a central crossbeam, forming a gantry. A scraper is mounted on the crossbeam, precisely machined from a special metal that is resistant to acid and alkali corrosion. Inside the scraper is a hollow cavity for storing photoresist, which is connected to the photoresist inlet and bubble exhaust lines. A narrow slit runs horizontally below the scraper, with a gap of approximately 100 μm. Photoresist enters the slit from the scraper's internal cavity through the scraper's discharge port and is applied to the raw material to be coated.

[0006] In the current manufacturing process, there are two common ways to prevent the Slit scraper from being blocked and preventing glue from being discharged.

[0007] Method 1: Soak the Slit scraper die outlet in the cleaning solution in the standby state; Method 2: Perform multiple debonding operations before Slit coating, wipe the scraper multiple times, and increase the pressure of the photoresist supply liquid to reduce the occurrence of glue failure.

[0008] Regarding the solution in the above-mentioned method 1 in which the scraper die head outlet is immersed in the cleaning liquid during standby, its disadvantage 1 is that bubbles may be generated in the process of the scraper being pulled up from the liquid, causing the formation of hollow pinholes in the coated plate; its disadvantage 2 is that the immersion cleaning liquid will mix with the photoresist at the slit outlet, resulting in differences in the composition of the photoresist and affecting its quality, and a large amount of glue removal is required before coating, resulting in waste of photoresist.

[0009] like Figure 5 As shown, in an ideal state, the photoresist 8 should be continuously and evenly distributed. However, for the solution of multiple glue removal and multiple wiping in the above-mentioned method 2, its disadvantage 1 is that the width of the Slit coating scraper is only 100um, and incomplete cleaning may cause local areas to not discharge glue during glue coating, such as Figure 6 As shown, it causes glue coating NG, and some areas of the scraper outlet do not discharge glue; its disadvantage 2 is: wiping the scraper outlet multiple times increases the working hours, and manual wiping will carry particles to the glue coating cavity, causing glue coating defects; its disadvantage 3 is: the photoresist supply pressure increases, and the corresponding photoresist consumption will also increase proportionally. Summary of the Invention

[0010] The present invention provides a cleaning system for a mask photoresist coating die head, which aims to solve the problem of blockage of a scraper glue outlet, improve the generation of glue bubbles, improve quality problems caused by differences in photoresist components, improve particle contamination caused by repeated scraper wiping, and improve the problem of increased photoresist consumption caused by pressurized glue removal and multiple cleaning and glue removal.

[0011] The present invention is achieved through the following technical solution: a cleaning system for a mask photoresist coating die head, comprising a frame and a crossbeam, wherein the crossbeam is connected to the frame, a scraper is connected to the crossbeam, a cleaning liquid tank is provided below the scraper, a cleaning agent is contained in the cleaning liquid tank, the distance between the liquid level of the cleaning agent and the glue outlet of the scraper is 1-5 mm, and the cleaning agent can dissolve and clean the photoresist on the scraper after volatilization.

[0012] Compared with the existing technology, this solution has the following advantages and beneficial effects: In this solution, there is a distance between the scraper's glue outlet and the liquid surface of the cleaning agent. The scraper's glue outlet does not contact the cleaning agent, and the photoresist on the scraper is dissolved and cleaned by the volatilization of the cleaning agent. This method in this solution uses non-contact volatilization fumigation cleaning, which not only ensures that the scraper's glue outlet is not blocked, but also simultaneously solves the following four problems: ① Quality problems caused by changes in the photoresist composition due to immersion of the scraper die in the cleaning agent; ② Bubble problems caused by the pulling action between the scraper die and the liquid surface of the cleaning agent during immersion cleaning; ③ Particle contamination problem caused by repeated wiping of the scraper die outlet; ④ Increased photoresist consumption caused by increased discharge pressure.

[0013] Furthermore, the cleaning agent is acetone.

[0014] Beneficial effect: Acetone is selected as the cleaning agent in this solution, which performs better in non-contact cleaning methods and has better cleaning effects.

[0015] Furthermore, the distance between the liquid surface of the cleaning agent and the glue outlet of the scraper is less than 2 mm.

[0016] Beneficial effect: In this solution, when the distance between the glue outlet of the scraper and the liquid level of the cleaning agent is controlled to be less than 2 mm, the scraper only needs to be wiped once to evenly discharge glue.

[0017] Furthermore, a liquid level sensor for detecting the water level of the cleaning liquid tank is provided on one side of the cleaning liquid tank.

[0018] Beneficial effect: In this solution, the liquid level decreases due to the volatilization of the cleaning agent, and the setting of the liquid level sensor can detect the water level of the cleaning agent tank. Combined with the automatic liquid replenishing device, the cleaning agent tank can be replenished with liquid, so that the cleaning agent in the cleaning agent tank can always be maintained at the same depth.

[0019] Furthermore, one side of the cleaning liquid tank is connected to a liquid measuring tube, the water level of the liquid measuring tube is consistent with the water level of the cleaning liquid tank, and the liquid level sensor is installed on the liquid measuring tube for measuring its water level.

[0020] Beneficial effect: In this solution, a liquid measuring tube is connected to one side of the cleaning liquid tank. The liquid level sensor only needs to detect the liquid level of the liquid measuring tube to indirectly obtain the liquid level information of the cleaning liquid tank. The setting of the liquid measuring tube in this solution is more convenient for the installation of the liquid level sensor, and can avoid the installation of the liquid level sensor occupying the space of the cleaning liquid tank, thereby avoiding affecting the adjustment of the distance between the scraper and the liquid level in the cleaning liquid tank.

[0021] Furthermore, a partition is provided in the cleaning liquid tank, which divides the cleaning liquid tank into a cleaning chamber and a waste liquid chamber. An overflow tank connecting the cleaning chamber and the waste liquid chamber is provided on the upper part of the partition.

[0022] Beneficial effect: The setting of the partition in this solution divides the cleaning liquid tank into two independent chambers, wherein the cleaning chamber is used to store cleaning agents for volatilization and fumigation cleaning of the scraper, and the waste liquid chamber can collect excess cleaning agents overflowing from the cleaning chamber. The setting of the overflow tank in this solution can automatically flow through the overflow tank to the waste liquid chamber when the liquid level in the cleaning chamber exceeds the set requirement, thereby facilitating the control of the gap between the glue outlet of the scraper and the liquid level in the cleaning liquid chamber to be controlled at the optimal position.

[0023] Furthermore, a drain port is provided at the bottom of the waste liquid chamber.

[0024] Beneficial effect: The arrangement of the liquid discharge port in this solution facilitates the discharge of the liquid medicine collected in the waste liquid chamber.

[0025] Furthermore, the liquid discharge port is connected to a waste liquid pipe.

[0026] Beneficial effect: The provision of the waste liquid pipe facilitates the discharge of the liquid medicine in the waste liquid cavity to a designated location.

[0027] Furthermore, the cleaning liquid tank is made of Teflon.

[0028] Beneficial effect: The material of the cleaning solution tank in this solution is Teflon, which will not be corroded by cleaning agents and photoresist. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings: Figure 1 This is a front view of an embodiment of a cleaning system for a mask photoresist coating die head according to the present invention; Figure 2 This is a front view of a cleaning solution tank in an embodiment of a cleaning system for a mask photoresist coating die head of the present invention; Figure 3 A top view of a cleaning solution tank in an embodiment of a cleaning system for a mask photoresist coating die head of the present invention; Figure 4 This is a process diagram of photoresist coating using the Slit+Spin mode commonly used in the prior art; Figure 5 This is a schematic diagram showing that the photoresist discharged from the scraper outlet is continuously and evenly distributed under ideal conditions in the prior art; Figure 6 This is a schematic diagram of the state in which the glue outlet of the scraper in the prior art discharges glue unevenly; Figure 7This is a schematic diagram comparing the effects of using different cleaning agents and different liquid level gaps in a cleaning solution tank of a cleaning system for a mask photoresist coating die head of the present invention.

[0030] Markings and corresponding parts names in the accompanying drawings: Left support column 1, right support column 2, crossbeam 3, scraper 4, glue outlet 5, photoresist liquid inlet pipeline 6, cleaning liquid tank 7, cleaning chamber 701, waste liquid chamber 702, partition 703, photoresist 8, liquid level sensor 9, overflow tank 10, waste liquid pipe 11, drain port 12, liquid measuring tube 13. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0032] Example 1 like Figure 1 As shown, this embodiment 1 provides a cleaning system for a mask photoresist coating die head, including a frame and a beam 3, the beam 3 is connected to the frame, in this embodiment the frame includes a left support column 1 and a right support column 2, the two ends of the beam 3 are respectively connected to the top of the left support column 1 and the right support column 2, a scraper 4 is connected to the beam 3, the scraper 4 has a hollow cavity inside for storing photoresist 8, the internal cavity of the scraper 4 is connected to the existing photoresist liquid inlet pipeline 6 and the bubble exhaust pipeline, the positional relationship and connection relationship between the frame, the beam 3 and the scraper 4, as well as the photoresist liquid inlet pipeline and the bubble exhaust pipeline are existing technologies, which can be known to those skilled in the art and will not be repeated here.

[0033] A cleaning liquid tank 7 is provided below the scraper 4. The cleaning liquid tank 7 contains a cleaning agent. The distance between the liquid level of the cleaning agent and the glue outlet 5 of the scraper 4 is 1-5 mm. The cleaning agent can dissolve and clean the photoresist 8 on the scraper 4 after evaporation. Specifically, the cleaning agent in this embodiment is acetone, and the distance between the liquid level of the cleaning agent and the glue outlet 5 of the scraper 4 is less than 2 mm. In this embodiment, the crossbeam 3 can slide horizontally along the left support column 1 and the right support column 2. The horizontal sliding of the crossbeam 3 can be achieved by a ball screw pair structure or a telescopic rod structure in the prior art, which is not specifically limited here. During the horizontal sliding process of the crossbeam 3, the scraper 4 is driven to move. When the scraper 4 needs to be cleaned, the scraper 4 is moved to the top of the cleaning liquid tank 7. The glue outlet of the scraper 4 can be 2 mm away from the liquid level of the cleaning agent.

[0034] Combine Figure 7As shown, the present invention abandons the cleaning method of immersing the scraper 4 die head in the cleaning agent in the glue coating standby state, adopts a non-contact cleaning method, and captures the combined effects of the scraper 4 die head with different cleaning agents / different liquid level gaps in multiple groups of experiments, and finds the minimum number of wipes required for the scraper 4 die head to prevent condensation. Figure 7 From the data, it can be concluded that acetone performs well in non-contact cleaning. When the distance between the glue outlet 5 of the scraper 4 and the acetone liquid level is controlled to be less than 2 mm, the scraper 4 only needs to be wiped once to evenly discharge glue.

[0035] In this embodiment, the cleaning solution tank 7 is made of Teflon, so that the cleaning solution tank 7 will not be corroded by acetone and the photoresist 8, thereby increasing the service life of the cleaning solution tank 7.

[0036] In this embodiment, the continuous volatilization of acetone can prevent the blockage of the glue discharge at the slit of the scraper 4 die head. By improving the blockage problem of the glue outlet 5 of the scraper 4, it is unnecessary to increase the liquid outlet pressure of the photoresist 8 and the number of liquid discharges of the scraper 4, thereby saving the amount of photoresist 8. By changing the cleaning method from direct immersion to air fumigation, it is prevented that the photoresist 8 is mixed with cleaning agents and changes in composition and properties. By changing the cleaning method from direct immersion to air fumigation, it is prevented that bubbles are generated by the pulling action of the die inlet and outlet liquid surface (bubbles will form a fatal defect - hollow pinhole when applied to the raw material).

[0037] Example 2 like Figure 2 and Figure 3 As shown, the difference between this embodiment and embodiment 1 is that a liquid level sensor 9 for detecting the water level of the cleaning liquid tank 7 is provided on one side of the cleaning liquid tank 7. In this embodiment, a liquid measuring tube 13 is connected to the left side of the cleaning liquid tank 7. The water level of the liquid measuring tube 13 is consistent with the water level of the cleaning liquid tank 7. In this embodiment, the liquid measuring tube 13 is arranged in an L shape, and the part of the side liquid tube connected to the cleaning liquid tank 7 is close to the bottom of the cleaning liquid tank 7. The liquid level sensor 9 is installed on the liquid measuring tube 13 to measure its water level. The liquid level sensor detects the water level on the measuring tube to obtain the water level of the cleaning liquid tank 7, and the setting of the liquid measuring tube 13 enables the liquid level sensor 9 to be installed on the liquid measuring tube 13, thereby avoiding interference with the position between the cleaning liquid tank 7 and the scraper head.

[0038] In this embodiment, a liquid level sensor 9 is installed on the left side of the cleaning liquid tank 7, and cooperates with the existing automatic liquid replenishing device to ensure that the cleaning liquid is always maintained at the same depth, thereby ensuring that the gap between the scraper 4 and the cleaning liquid surface is always controlled at the optimal gap position, and the liquid level will not be too low due to volatilization of the cleaning agent.

[0039] Example 3 like Figure 2 and Figure 3 As shown, the difference between this embodiment and the embodiment is that: in this embodiment, a partition 703 is provided in the cleaning liquid tank 7, and the partition 703 in this embodiment is located on the right side of the cleaning liquid tank 7. The partition 703 separates the cleaning liquid tank 7 into a cleaning chamber 701 and a waste liquid chamber 702 that are independent of each other. In this embodiment, the partition 703 and the cleaning liquid tank 7 are integrally formed.

[0040] In order to ensure that the gap between the glue outlet 5 of the scraper 4 and the liquid surface of the cleaning agent is always controlled at the optimal gap position and the liquid level will not be too high due to human or other reasons, in this embodiment, an overflow groove 10 connecting the cleaning chamber 701 and the waste liquid chamber 702 is opened on the upper part of the partition 703. When the liquid level exceeds the set requirement, it will be automatically adjusted through the overflow groove 10.

[0041] In this embodiment, a drain port 12 is provided at the bottom of the waste liquid chamber 702 , and a waste liquid pipe 11 is connected to the drain port 12 . The waste liquid pipe 11 can discharge the liquid in the waste liquid chamber 702 to a designated location for collection and treatment.

[0042] This invention achieves excellent non-contact cleaning of the squeegee head by selecting the right cleaning agent type, integrating a cleaning tank level sensor with existing automatic refilling and overflow tank design, and rationally setting the gap between the squeegee head and the acetone liquid level. This reduces photoresist usage and mitigates quality issues associated with immersion cleaning.

[0043] Example 4 The difference between this embodiment and embodiment 1 is that this embodiment discloses a method for cleaning a mask photoresist coating die head, comprising the following steps: 1. When the liquid in the cleaning liquid tank is lower than the set liquid level, the liquid level sensor will return the detected liquid level to the control computer; 2. The control computer starts the automatic liquid replenishment system, pressurizes the liquid supply pipeline, and opens the liquid supply valve; 3. When the liquid level sensor detects that the liquid level in the cleaning tank reaches the set value, it returns the signal to the control computer; 4. The control computer shuts down the automatic rehydration system, relieves the pressure in the liquid medicine supply pipeline, and closes the liquid medicine supply valve; 5. If, due to accidental factors, such as when cleaning agent is added to the cleaning agent tank by mistake, the cleaning agent will be discharged into the waste liquid chamber 702 through the overflow tank 10 on the right side; 6. When the Slit blade coating is completed, manually clean the blade edge with a dust-free cloth; 7. Control the computer to drive the crossbeam to slide horizontally, and move the Slit scraper to the top of the cleaning solution tank, with the scraper's glue outlet 2mm away from the cleaning liquid surface; 8. Acetone continues to volatilize and react with the photoresist at the scraper outlet, ensuring that when in standby mode, the photoresist at the scraper outlet will not condense and cause the outlet to be blocked.

[0044] It should be noted that the above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cleaning system for a mask photoresist coating die head, comprising a frame and a crossbeam, wherein the crossbeam is connected to the frame, and a scraper is connected to the crossbeam, characterized in that: A cleaning liquid tank is provided below the scraper, in which cleaning agent is contained. The distance between the liquid surface of the cleaning agent and the glue outlet of the scraper is 1-5mm. The cleaning agent can dissolve and clean the photoresist on the scraper after volatilization.

2. A cleaning system for a mask photoresist coating die head according to claim 1, characterized in that: The cleaning agent is acetone.

3. A cleaning system for a mask photoresist coating die head according to claim 1, characterized in that: The distance between the liquid surface of the cleaning agent and the glue outlet of the scraper is less than 2 mm.

4. A cleaning system for a mask photoresist coating die head according to any one of claims 1 to 3, characterized in that: A liquid level sensor for detecting the water level of the cleaning liquid tank is arranged on one side of the cleaning liquid tank.

5. A cleaning system for a mask photoresist coating die head according to claim 4, characterized in that: One side of the cleaning liquid tank is connected to a liquid measuring tube, the water level of the liquid measuring tube is consistent with the water level of the cleaning liquid tank, and the liquid level sensor is installed on the liquid measuring tube to measure the water level.

6. A cleaning system for a mask photoresist coating die head according to any one of claims 1 to 3, characterized in that: A partition is arranged in the cleaning liquid tank, and the partition divides the cleaning liquid tank into a cleaning chamber and a waste liquid chamber. An overflow tank connecting the cleaning chamber and the waste liquid chamber is opened on the upper part of the partition.

7. A cleaning system for a mask photoresist coating die head according to claim 6, characterized in that: A liquid discharge port is provided at the bottom of the waste liquid chamber.

8. A cleaning system for a mask photoresist coating die head according to claim 7, characterized in that: The liquid discharge port is connected with a waste liquid pipe.

9. A cleaning system for a mask photoresist coating die head according to claim 1, characterized in that: The cleaning liquid tank is made of Teflon.

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