Device for thinning and pickling base material of metal mask plate

Abstract

The invention provides a device for thinning and pickling a base material of a metal mask plate, the device comprises an etching unit and a pickling unit, the etching unit further comprises a first sponge roller above the base material, and after the base material is thinned by an etching solution, the first sponge roller is separated from the first sponge roller. Residual etching liquid on a base material passes through the first sponge roller to form an etching liquid film which is uniformly distributed; the pickling unit sprays a pickling solution to remove the etching solution film on the base material; the pickling unit is provided with a metal roller used for extruding a base material and solving the problem that an etching liquid film on the base material is damaged, a second sponge roller is arranged above the metal roller and used for absorbing a pickling solution carried on the metal roller, a shielding structure is further arranged, a spraying head of the pickling unit is changed into a liquid knife nozzle, and therefore the pickling solution film on the base material is not damaged. Therefore, the etching liquid film is completely clear at the first time when the base material is in contact with the metal roller, so that the etching liquid film at each position on the base material is uniformly pickled, and the Mura phenomenon is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of metal mask plates, and more particularly, to an apparatus for thinning and pickling the substrate of a metal mask plate. Background Art

[0002] Currently, the substrate for producing OLED metal mask plates is a stainless steel thin strip, which plays a crucial role in multiple key industries due to its excellent corrosion resistance, strength, and processing performance. The microelectronics and semiconductor industries require thinner stainless steel foils when manufacturing fine chips and sensors, and flexible display technologies are seeking ultra-thin stainless steel foils that can serve as the substrate for bendable display devices.

[0003] In the prior art, as Figure 1 shown, multiple spray heads 3 are provided in the etching unit, and the etching solution is sprayed through the spray heads 3 to etch and thin the substrate 1 of the metal mask plate. A sponge roller 6 is provided at the end of the etching unit, and after passing through the sponge roller 6, a uniformly distributed etching solution film is formed on the surface of the substrate 1. A pickling unit is provided after the etching unit. The pickling unit includes multiple spray heads 4 that can spray pickling solution. Parameters such as the swing speed, spraying pressure, and concentration of the sprayed pickling solution, as well as the moving speed of the substrate 1 of the metal mask plate, are all set parameters. As the substrate 1 of the metal mask plate enters the pickling unit, the etching solution film thereon is completely removed by the pickling solution.

[0004] However, there are various factors in the prior art that affect the uniform pickling of the etching solution film, ultimately resulting in the occurrence of the Mura phenomenon. For example, above the substrate, specifically including: (1) During the process of the substrate 1 of the metal mask plate from passing through the sponge roller 6 in the etching unit to entering the range of action of the spray head 4 in the pickling unit, as Figure 1 shown, the moving range corresponding to the substrate 1 of the metal mask plate is L. In the prior art, only conveyor rollers 5 are usually provided at the opposite ends of the etching unit and the pickling unit respectively to tension and convey the substrate 1. However, the substrate 1 at the position L in the middle of the etching unit and the pickling unit has uneven stress at each position due to insufficient tension, resulting in the breakage of the uniformly formed etching solution film on the substrate at this position L. As a result, the substrate 1 is unevenly pickled after entering the pickling unit, and the Mura phenomenon occurs.

[0005] (2) During the process of the substrate 1 of the metal mask plate from passing through the sponge roller 6 in the etching unit to entering the range of action of the spray head 4 in the pickling unit, that is, corresponding to Figure 1At the position L of the metal mask substrate, during the process of the etching unit spray head 3 spraying the etching solution, the etching solution is randomly splashed onto the uniform etching solution film at this section of the position L, and / or during the process of the pickling unit spray head 4 spraying the pickling solution, the pickling solution is randomly splashed onto the uniform etching solution film at this section of the position L. As a result, after this section of the metal mask substrate enters the pickling unit, due to some positions being contaminated with a small amount of pickling solution in advance, or some positions still being splashed with a small amount of etching solution after passing through the sponge roller, when entering the pickling unit for pickling, and parameters such as the swing speed, spraying pressure, and concentration of the spraying pickling solution of the spray head, as well as the moving speed of the metal mask substrate are all set parameters, the etching solution films at various positions on the substrate cannot be evenly pickled, resulting in Mura phenomenon.

[0006] (3) The pickling solution unit spray head 4 sprays the pickling solution on the metal mask substrate 1 to remove the etching solution film formed after the substrate 1 passes through the metal roller 6. During the process of spraying the pickling solution, the pickling solution will randomly splash after being sprayed onto the substrate 1, resulting in uneven quality of the pickling solution received at various positions on the entire substrate 1. Eventually, the etching solution film on the substrate 1 is unevenly pickled, resulting in Mura phenomenon.

[0007] Similarly, below the substrate, there are also problems such as the etching solution film being damaged during the process of the metal mask substrate 1 from the etching unit to entering the action range of the pickling unit spray head 4, being contaminated by the etching solution and pickling solution splashed from both sides, and the etching solution film being unevenly pickled due to the random splash of the pickling solution, resulting in Mura phenomenon. Summary of the Invention

[0008] The present invention provides a device for etching and pickling a metal mask substrate, including an etching unit and a pickling unit, which can avoid the damage of the formed etching solution film on the substrate during the process of the substrate running from the etching unit to the pickling unit, avoid the contamination of the etching solution film by the etching solution and pickling solution on both sides, and eliminate the influence of the random splash of the pickling solution in the pickling unit in the prior art on the uneven pickling of the etching solution film.

[0009] The specific solution is as follows.

[0010] A device for thinning and pickling the substrate of a metal mask, along the running direction of the substrate, the device successively includes an etching unit and a pickling unit from front to back, the etching unit and the pickling unit are respectively arranged on the upper and lower sides of the substrate, the etching unit sprays the etching solution to etch and thin the substrate, above the substrate, the etching unit further includes a first sponge roller, after the substrate is thinned by the etching solution, the remaining etching solution on the substrate forms a uniformly distributed etching solution film through the first sponge roller; The pickling unit sprays the pickling solution to remove the etching solution film on the substrate; The pickling unit is provided with a metal roller for extruding the base material. Above the metal roller, there is a second sponge roller. The metal roller, the first sponge roller, and the second sponge roller rotate on their own axes during the movement of the base material. The rotational angular velocities of the metal roller and the second sponge roller are the same, and the linear velocities of the rotation of the metal roller and the first sponge roller are the same as the moving speed of the base material.

[0011] Further, above the base material, between the etching unit and the pickling unit, there is a partition structure. The device also includes a shielding structure. The shielding structure includes a recovery tank. The etching solution sprayed by the etching unit towards the pickling unit is blocked by the partition structure and recovered by the recovery tank.

[0012] Further, in the vertical direction, the recovery tank is located below the partition structure. In the horizontal direction, the recovery tank extends from the pickling unit towards the etching unit, and one end of the extension of the recovery tank extends beyond the first sponge roller in the horizontal direction.

[0013] Further, the shielding structure includes a baffle. The baffle is located on the side of the metal roller away from the partition structure in the vertical direction.

[0014] Further, the lowest point of the baffle in the vertical direction is lower than the top end of the second sponge roller.

[0015] Further, the recovery tank, the baffle, and the partition structure are connected.

[0016] Further, the pickling unit is provided with an upper liquid knife nozzle. The upper liquid knife nozzle is located behind the metal roller and sprays pickling solution on the rear side surface of the metal roller.

[0017] Further, below the base material, the etching unit includes an overflow box. The etching solution gushing out from the overflow box forms a uniform etching solution film on the lower surface of the base material. The pickling unit includes a lower conveyor roller that rotates on its own axis. The lower conveyor roller is located below the base material at a position corresponding to the metal roller above the base material. The linear velocity of the rotation of the lower conveyor roller is the same as the moving speed of the base material.

[0018] Further, the spraying height H2 of the etching solution of the etching unit below the base material towards the lower surface of the base material is less than the spraying height H1 of the etching unit above the base material towards the upper surface of the base material.

[0019] Further, the pickling unit is provided with a lower liquid knife nozzle. The lower liquid knife nozzle sprays pickling solution at the position behind the lower conveyor roller on the base material.

[0020] The present invention has the following technical effects: 1. Above the base material (1)In the present invention, a metal roller is provided in the middle of the etching unit and the pickling unit. The metal roller extrudes the substrate of the metal mask plate through self-rotation to maintain uniform stress at each position of the substrate during operation, so that the etching liquid film formed on the surface of the substrate after passing through the first sponge roller of the etching unit remains flat and unbroken. On the other hand, the metal roller also has the function of preventing a part of the pickling liquid in the pickling unit from splashing onto the substrate between the metal roller and the first sponge roller. In addition, since the metal roller is close to the spray head of the pickling unit, it inevitably carries pickling liquid. To prevent the pickling liquid carried by the metal roller from being thrown out onto the position between the metal roller and the first sponge roller on the substrate during the self-rotation of the metal roller, a second sponge roller is provided on the metal roller to cooperate with the metal roller for self-rotation. During the self-rotation process, the second sponge roller can evenly absorb the residual pickling liquid on the metal roller, avoiding the pickling liquid being thrown out onto the position between the metal roller and the first sponge roller on the substrate.

[0021] (2)In the present invention, a shielding structure is provided on both sides of the second sponge roller and the metal roller in the middle of the etching unit and the pickling unit to further prevent the etching liquid in the etching unit and the pickling liquid in the pickling unit from splashing onto the position between the metal roller and the first sponge roller on the substrate, avoiding random contamination of the uniform etching liquid film formed at this position on the substrate by the etching liquid and the pickling liquid.

[0022] (3)In the present invention, the spray head in the pickling unit in the prior art is cancelled, and a liquid knife nozzle is used instead. The upper liquid knife nozzle is arranged behind the metal roller to spray pickling liquid on the rear side surface of the metal roller.

[0023] Above the substrate, the upper liquid knife nozzle is used to spray pickling liquid towards the side surface of the metal roller. On the one hand, the pickling liquid is used to clean a small amount of etching liquid carried by the metal roller when it contacts the etching liquid film on the surface of the substrate during self-rotation. On the other hand, the pickling liquid flows along the side surface of the metal roller to the bottom of the metal roller. When the substrate moves to the moment of contacting the bottom of the metal roller, the pickling liquid on the metal roller can completely remove the pickling liquid film on the substrate in the first time, avoiding the pickling liquid sprayed by the spray head from contacting the surface of the substrate and randomly splashing after the substrate moves to the pickling unit, resulting in uneven quality of the pickling liquid received at each position on the substrate.

[0024] 2. Below the substrate (1) In the etching unit of the present invention, an overflow box is provided. The etching solution gushes upward through the overflow box to form a uniformly distributed etching solution film on the lower surface of the substrate. A lower conveying roller is arranged at a position corresponding to the upper metal roller above. The substrate is supported by the lower conveying roller. Similar to the function of the upper metal roller, it can maintain the substrate in a tensioned state between the etching unit and the pickling unit, preventing the etching solution film at this position from being damaged. Below the substrate, due to the action of gravity, even if the pickling solution carried by the lower conveying roller is thrown out from the position between the lower conveying roller and the overflow box during the rotation, it can freely fall, avoiding splashing onto the lower surface of the substrate.

[0025] (2) By adjusting the spraying height of the etching solution in the etching unit below the substrate onto the substrate surface and combining with the shielding effect of the lower conveying roller, the present invention can avoid the uniformly distributed etching solution film between the overflow box and the lower conveying roller on the lower surface of the lower substrate from being splashed and contaminated by the etching solution and pickling solution on both sides. A) In the etching unit, adjust the spraying height H2 of the lower etching solution onto the substrate surface to be less than the spraying height H1 of the upper etching solution onto the substrate surface, so as to reduce the spraying pressure of the lower etching solution on the lower surface of the substrate. Combining with the gravitational influence of the liquid droplets, finally, a small amount of splashed etching solution can directly fall, avoiding splashing onto the etching solution film between the overflow box and the lower conveying roller. B) In the pickling unit, the lower liquid knife nozzle sprays the pickling solution to the position behind the lower conveying roller on the upper and lower sides of the substrate. Due to gravity, the sprayed pickling solution will be blocked by the lower conveying roller, so that the pickling solution cannot splash from the pickling unit onto the uniformly distributed etching solution film on the upper surface of the substrate between the lower conveying roller and the overflow box.

[0026] (3) The present invention cancels the spray head in the pickling unit in the prior art and also uses a liquid knife nozzle below the substrate. The lower liquid knife nozzle sprays the pickling solution to the position behind the lower conveying roller on the upper and lower sides of the substrate. The impact force carried by the pickling solution sprayed on the lower surface of the substrate enables the pickling solution to move along the lower surface of the substrate to the surface of the lower conveying roller. When the substrate passes through the etching unit from front to back and enters the pickling unit, at the moment when the lower surface of the substrate contacts the lower conveying roller, the pickling solution on the lower conveying roller can completely remove the etching solution film on the lower surface of the substrate. On the other hand, the pickling solution on the lower conveying roller can also be used to remove a small amount of etching solution carried by the contact between the lower conveying roller and the lower surface of the substrate. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments of the present invention. It should be understood that the following drawings only show some embodiments of the present invention, so they should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a device for thinning and pickling the substrate of a metal mask plate in the prior art.

[0029] Figure 2 It is a device for thinning and pickling the substrate of a metal mask plate provided by the present invention.

[0030] In the figure, 1. Substrate of metal mask plate, 2. Partition structure, 3. Spraying head of etching unit, 4. Spraying head of pickling unit, 5. Conveyor roller, 6. First sponge roller, 7. Metal roller, 8. Second sponge roller, 9. Recovery tank, 10. Baffle, 11. Connection structure, 12. Upper liquid knife nozzle, 13. Lower conveyor roller, 14. Overflow box, 15. Lower liquid knife nozzle. Specific embodiments

[0031] Next, the technical solutions in the embodiments of the present invention will be described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0032] This embodiment discloses a device for thinning and pickling the substrate of a metal mask plate. The etching unit and the pickling unit are respectively arranged on the upper and lower sides of the substrate. As Figure 2 shown, along the running direction of the substrate 1, the device sequentially includes an etching unit and a pickling unit from front to back. A partition unit 2 may further be included between the etching unit and the pickling unit to separate the two different units.

[0033] The etching unit includes a spraying head 3 that can spray etching solution to etch and thin the substrate 1. Above the substrate 1, the etching unit further includes a first sponge roller 6. After the substrate 1 is thinned by the etching solution treatment, the etching solution remaining on the substrate 1 forms a uniformly distributed etching solution film through the first sponge roller 6; the pickling unit sprays pickling solution to remove the etching solution film on the substrate 1.

[0034] In addition to respectively arranging conveyor rollers 5 at opposite ends of the etching unit and the pickling unit to tension and convey the substrate 1, a rotatable metal roller 7 is arranged in the pickling unit above the substrate 1 for extruding the substrate 1 to prevent the substrate 1 from sagging due to insufficient tension when running to the middle position between the etching unit and the pickling unit, thereby avoiding the breakage of the uniformly distributed etching solution film on the substrate 1. In addition, the metal roller 7 also has the function of blocking part of the pickling solution from splashing onto the substrate surface between the metal roller 7 and the first sponge roller 6.

[0035] The metal roller 7 provided in the pickling unit rotates on its own while carrying the pickling solution sprayed by the pickling unit. During the rotation, the pickling solution carried splashes onto the substrate 1 between the metal roller 7 and the first sponge roller 6, resulting in a small amount of pickling solution randomly contaminating this part of the substrate 1 in advance. Eventually, after entering the pickling unit, it is unevenly pickled, causing Mura phenomenon. Therefore, a rotatable second sponge roller 8 is provided on the metal roller 7. By the cooperation of the second sponge roller 8 and the rotation of the metal roller 7, the pickling solution carried by the metal roller 7 can be absorbed, preventing the pickling solution from being thrown out onto the substrate 1 between the metal roller 7 and the first sponge roller 6 during the rotation of the metal roller 7.

[0036] The metal roller 7 and the second sponge roller 8 have the same angular velocity of self-rotation, and the linear velocities of self-rotation of the metal roller 7 and the first sponge roller 6 are the same as the moving velocity of the substrate 1.

[0037] Furthermore, in order to prevent the etching solution in the etching unit and the pickling solution in the pickling unit from being sprayed or splashed onto the substrate 1 between the metal 7 and the first sponge roller 6, a shielding structure is provided. The shielding structure includes a recovery groove 9 and a baffle 10. In the vertical direction, the recovery groove 9 is located below the partition structure 2. In the horizontal direction, the recovery groove 9 extends from the pickling unit towards the etching unit, and one end of the extension to the recovery groove 9 extends beyond the first sponge roller 6 in the horizontal direction, preventing the etching solution from crossing the first sponge roller 6 to contaminate the substrate 1 between the first sponge roller 6 and the metal roller 7. The etching solution sprayed or splashed from the etching unit towards the pickling unit direction is blocked by the partition structure 2 and recovered by the recovery groove 9. The baffle 10 is located on the side of the metal roller 7 away from the partition structure 2 in the vertical direction. And in order to shield the pickling solution splash as much as possible, the lowest point of the baffle 10 in the vertical direction is lower than the top end of the second sponge roller 8.

[0038] Furthermore, the recovery groove 9 and the baffle 10 can be connected to the partition structure 2. Preferably, the recovery groove 9 and the baffle 10 can be respectively connected to the partition structure 2 through the connection structure 11.

[0039] After the substrate 1 passes through the metal roller 7 and enters the pickling unit, in order to prevent the pickling solution sprayed by the spray head from splashing on the substrate 1, resulting in uneven pickling solution received at various positions on the substrate 1, in this embodiment, upper liquid knife nozzles 12 are respectively provided behind the metal roller 7 on the upper surface and the lower surface of the substrate 1 to spray the pickling solution to remove the etching solution film on the substrate 1.

[0040] Above the substrate 1, the upper liquid knife nozzle 12 sprays pickling solution onto the rear side surface of the metal roller 7. On the one hand, the pickling solution is used to clean a small amount of etching solution carried by the metal roller 7 when it rotates and contacts the etching solution film on the surface of the substrate 1. On the other hand, the pickling solution flows along the side surface of the metal roller 7 to the bottom of the metal roller 7. When the substrate 1 moves to contact the metal roller 7, the pickling solution can completely remove the etching solution film on the substrate 1 in the first time, so as to ensure that the etching solution film on each position of the substrate 1 is uniformly and completely removed when it moves to contact the metal roller 1 for the first time.

[0041] Below the substrate 1, an overflow box 14 is arranged in the etching unit, and the etching solution gushes upward through the overflow box 14 to form a uniformly distributed etching solution film on the lower surface of the substrate 1. In addition, a lower conveyor roller 13 is arranged at a position corresponding to the upper metal roller 5, and the substrate 1 is supported by the lower conveyor roller 13, so as to maintain the substrate 1 in a tension state between the etching unit and the pickling unit and prevent the etching solution film at this position from being damaged. On the other hand, below the substrate 1, due to the action of gravity, the pickling solution carried by the lower conveyor roller 13 can freely fall even if it is thrown out from the position between the lower conveyor roller 13 and the overflow box 14 during the rotation process, avoiding splashing onto the lower surface of the substrate 1.

[0042] Furthermore, in this embodiment, by adjusting the spraying height of the etching solution in the etching unit below the substrate 1 onto the surface of the substrate 1 and combining the shielding effect of the lower conveyor roller 13, it is possible to avoid the uniform etching solution film between the overflow box 14 and the lower conveyor roller 13 on the lower surface of the lower substrate 1 from being splashed and polluted by the etching solution and pickling solution on both sides.

[0043] Specifically, in the etching unit, adjust the spraying height H2 of the lower etching solution onto the surface of the substrate 1 to be less than the spraying height H1 of the upper etching solution onto the surface of the substrate 1, so as to reduce the spraying pressure of the lower etching solution on the lower surface of the substrate 1. Combining the influence of the gravity of the liquid droplets, finally, a small amount of splashed etching solution can directly fall, avoiding splashing onto the etching solution film between the overflow 14 and the lower conveyor roller 13.

[0044] In the pickling unit, the lower liquid knife nozzle 15 sprays pickling solution to a position behind the lower conveyor roller 13 on the substrate. Due to gravity and the fact that the splashed pickling solution will be blocked by the lower conveyor roller 13, the pickling solution cannot splash from the pickling unit onto the uniform etching solution film on the surface of the substrate 1 between the lower conveyor roller 13 and the overflow box 14.

[0045] In addition, by also using a liquid knife nozzle below the substrate 1, the lower liquid knife nozzle 15 sprays the pickling solution onto the position behind the lower conveying roller 13 on the substrate 1. The impact force carried by the pickling solution sprayed on the lower surface of the substrate 1 enables the pickling solution to move along the lower surface of the substrate 1 to the surface of the lower conveying roller 13. When the substrate 1 passes through the etching unit from front to back and enters the pickling unit, at the moment when the lower surface of the substrate 1 contacts the lower conveying roller 13, the pickling solution on the lower conveying roller 13 can completely remove the etching solution film on the lower surface of the substrate 1. On the other hand, the pickling solution on the lower conveying roller 13 can also be used to remove a small amount of etching solution carried by the contact between the lower conveying roller 13 and the lower surface of the substrate 1.

[0046] Therefore, the etching and pickling device of this embodiment can uniformly pickle the residual pickling solution on the upper and lower surfaces of the substrate, avoiding the occurrence of Mura phenomenon.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An apparatus for thinning and pickling the substrate of a metal mask plate. Along the running direction of the substrate, the apparatus successively includes an etching unit and a pickling unit from front to back. The etching unit and the pickling unit are respectively arranged on the upper and lower sides of the substrate. The etching unit sprays etching solution to etch and thin the substrate. Above the substrate, the etching unit further includes a first sponge roller. After the substrate is thinned by the etching solution, the etching solution remaining on the substrate forms a uniformly distributed etching solution film through the first sponge roller. The pickling unit sprays pickling solution to remove the etching solution film on the substrate. It is characterized in that The pickling unit is provided with a metal roller for extruding the substrate. Above the metal roller, there is a second sponge roller. The metal roller, the first sponge roller and the second sponge roller rotate self - respectively during the movement of the substrate. The self - rotation angular speeds of the metal roller and the second sponge roller are the same. The linear speeds of the self - rotation of the metal roller and the first sponge roller are the same as the moving speed of the substrate.

2. The device for thinning and pickling the substrate of a metal mask plate according to claim 1, characterized in that, Above the substrate, between the etching unit and the pickling unit, there is a separation structure. The apparatus further includes a shielding structure. The shielding structure includes a recovery tank. The etching solution sprayed by the etching unit towards the pickling unit direction is blocked by the separation structure and recovered by the recovery tank.

3. The device for thinning and pickling the substrate of a metal mask according to claim 2, characterized in that, In the vertical direction, the recovery tank is located below the separation structure. In the horizontal direction, the recovery tank extends from the pickling unit towards the etching unit, and one end of the extension of the recovery tank extends beyond the first sponge roller in the horizontal direction.

4. An apparatus for thinning and pickling the substrate of a metal mask plate according to claim 2, wherein, The shielding structure includes a baffle. The baffle is located on the side of the metal roller away from the separation structure in the vertical direction.

5. An apparatus for thinning and pickling the substrate of a metal mask plate according to claim 4, characterized in that, The lowest point of the baffle in the vertical direction is lower than the top end of the second sponge roller.

6. The device for thinning and pickling the substrate of a metal mask plate according to claim 4, characterized in that, The recovery tank, the baffle and the separation structure are connected.

7. An apparatus for thinning and pickling the substrate of a metal mask plate according to claim 1, characterized in that, The pickling unit is provided with an upper liquid knife nozzle. The upper liquid knife nozzle is located behind the metal roller and sprays pickling solution on the rear side surface of the metal roller.

8. An apparatus for thinning and pickling the substrate of a metal mask plate according to claim 1, characterized in that, Below the substrate, the etching unit includes an overflow box. The etching solution gushing out from the overflow box forms a uniformly distributed etching solution film on the lower surface of the substrate. The pickling unit includes a lower conveying roller that rotates self - respectively. The lower conveying roller is located below the substrate at a position corresponding to the metal roller above the substrate. The linear speed of the self - rotation of the lower conveying roller is the same as the moving speed of the substrate.

9. An apparatus for thinning and pickling the substrate of a metal mask plate according to claim 8, characterized in that, The spraying height H2 of the etching solution of the etching unit below the substrate towards the lower surface of the substrate is less than the spraying height H1 of the etching unit above the substrate towards the upper surface of the substrate.

10. A device for thinning and pickling the substrate of a metal mask plate according to claim 8, characterized in that, The pickling unit is provided with a lower liquid knife nozzle. The lower liquid knife nozzle is aimed at the position behind the lower conveying roller on the substrate and sprays pickling solution.

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