CN118547240B - Mask plate preparation method and mask plate - Google Patents

Abstract

The present invention discloses a method for preparing a mask plate and a mask plate, and relates to the technical field of mask plates. The method comprises the following steps: step S1. forming a photoresist film on one surface of a carrier plate; step S2. forming a slot with an inverted trapezoidal structure on the photoresist film; step S3. setting a reinforcing rib on the surface of the photoresist film; step S4. forming a first vacuum-plated foil film on the surface of the photoresist film and the reinforcing rib by a vacuum coating method, and forming a second vacuum-plated foil film in the slot; step S5. removing the photoresist film, separating the reinforcing rib and the first vacuum-plated foil film from the carrier plate and the second vacuum-plated foil film, and obtaining a mask sheet combination, which is composed of the reinforcing rib and the first vacuum-plated foil film; step S6. transferring the mask sheet combination to a mask frame, and binding it to the mask frame to obtain a mask plate. By this method, a mask plate with a flared opening can be obtained, and the mask sheet is not easy to wrinkle, deform, or crack during the preparation process.

Description

A method for preparing a mask plate and a mask plate

Technical Field

The present invention relates to the technical field of mask plates, and in particular to a mask plate preparation method and a mask plate.

Background Art

In the manufacturing process of OLED display screens, in order to evaporate the RGB light-emitting layer organic materials onto the RGB pixels of the substrate respectively, a precision mask (FMM) is set up to shield other pixels. The thickness of the current mass production FMM mask is generally 20 to 50 μm, and wet etching is usually used to form holes (evaporation patterns) through which the material vapor passes during evaporation. However, due to the isotropy of wet etching, it is difficult to make the holes smaller with thicker foils, resulting in limited resolution; in addition, since some organic materials have a certain evaporation incident angle when vapor is evaporated onto the substrate, in order to evenly fill the organic film in the substrate pixels, the mask is often made very thin. Generally speaking, the higher the pixel resolution, the thinner the mask is required. However, the thinner the mask, the weaker its strength. Weak mask sheets are prone to wrinkling or cracking, which brings difficult problems to binding, transportation, storage and organic material coating.

In this regard, the Chinese invention patent application with publication number CN117418193A discloses a method for preparing a mask plate and a mask plate. The method first bonds the mask sheet assembly to the mask frame before demolding, and the transparent carrier plate is used to fix the mask sheet so that the mask sheet can remain horizontal and is not easily broken when bonded. However, the method uses electroforming to form the mask sheet, which is a wet casting method. It not only requires a conductive film on the carrier plate, but also the opening formed by the mask sheet cannot be arc-shaped, and it is easy to introduce impurities. When the conductive film and the carrier plate are removed, the mask sheet is easily wrinkled, deformed or broken, which limits the promotion of this method.

It can be seen that the existing technology still needs to be improved and enhanced.

Summary of the invention

In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a mask plate preparation method and a mask plate, aiming to solve the defects of the mask plate being prone to wrinkling, deformation and cracking during the preparation process.

In order to achieve the above object, the present invention adopts the following technical solutions:

A method for preparing a mask plate, wherein the method comprises the following steps:

Step S1. forming a photoresist film on one surface of the carrier;

Step S2. forming a groove having an inverted trapezoidal structure on the photoresist film;

Step S3. Arranging a reinforcing rib on the surface of the photoresist film;

Step S4. forming a first vacuum-plated foil film on the surface of the photoresist film and the reinforcing ribs by a vacuum coating method, and forming a second vacuum-plated foil film in the slots;

Step S5. removing the photoresist film, separating the reinforcing ribs and the first vacuum-plated foil film from the carrier and the second vacuum-plated foil film, and obtaining a mask sheet assembly, wherein the mask sheet assembly is composed of the reinforcing ribs and the first vacuum-plated foil film;

Step S6: Transfer the mask sheet assembly to the mask frame and bind it to the mask frame to obtain a mask plate.

In the mask plate preparation method, in step S3, a magnetic plate is firstly arranged on the surface of the carrier plate opposite to the photoresist film, and a reinforcing rib is adsorbed on the surface of the photoresist film by utilizing the magnetism of the magnetic plate.

In the mask plate preparation method, in step S3, a layer of organic transparent adhesive film is coated on the surface of the reinforcing rib, and the reinforcing rib is attached to the photoresist film through the organic transparent adhesive film.

In the mask plate preparation method, the thickness of the first vacuum-plated foil film and the second vacuum-plated foil film is less than the depth of the slot, and the first vacuum-plated foil film is not connected to the second vacuum-plated foil film.

In the mask preparation method, in step S4, the vacuum coating method is selected from magnetron sputtering, ion plating, electron beam evaporation and laser evaporation.

In the mask plate preparation method, the material of the first vacuum-plated foil film and the second vacuum-plated foil film is selected from a combination of one or more of nickel-iron alloy, iron-cobalt-nickel alloy, iron-cobalt-smium alloy, ceramic, glass, diamond, and diamond-like carbon.

In the mask plate preparation method, the carrier plate is a transparent carrier plate, and a stripping film is provided between the carrier plate and the photoresist film.

In the mask plate preparation method, the stripping film is a gallium nitride film or an indium zinc nitride film, or a thermal stripping film.

In the mask plate preparation method, in step S6, the mask frame is cooled before being bound.

A mask plate is prepared by the method as described above, wherein the mask plate comprises a mask frame and a mask sheet, and the thickness of the mask sheet is 0.1-30 μm.

Beneficial effect: The present invention provides a mask plate preparation method and a mask plate. In the preparation method, a photoresist film with inverted trapezoidal slots can be used to obtain a first vacuum-coated foil film with a flared opening through vacuum coating. By attaching additional reinforcing ribs to the photoresist film, the first vacuum-coated foil film can always remain in an unfolded state during separation, transfer, and binding, and the mask plate can be prevented from wrinkling, deformation, and cracking, thereby better protecting the mask plate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a process flow chart of the method for preparing a mask provided by the present invention.

FIG. 2 is a diagram showing the first step of preparing a mask plate through a structural schematic diagram.

FIG. 3 is a second diagram of mask plate preparation steps represented by a structural schematic diagram.

FIG. 4 is an enlarged view of point A in FIG. 2 .

FIG. 5 is a third diagram of mask preparation steps represented by a structural schematic diagram.

Markings in the attached drawings: 1-carrier, 2-photoresist film, 3-slot, 4-magnetic plate, 5-reinforcing rib, 6-first vacuum-plated foil film, 7-second vacuum-plated foil film, 8-mask frame, 9-mask sheet assembly, 10-peeling film, 11-organic transparent adhesive film.

DETAILED DESCRIPTION

The present invention provides a method for preparing a mask plate and a mask plate. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

Please refer to FIG. 1 or FIG. 2 , a preferred embodiment of the present invention provides a method for preparing a mask plate, and the method comprises the following steps:

Step S1. Form a photoresist film 2 on one surface of the carrier 1, for example, by forming a layer of photoresist film 2 on the upper surface or the lower surface of the carrier 1 by coating with glue, wherein the thickness of the photoresist film 2 is greater than the thickness of the mask to be prepared.

Step S2. forming a slot 3 with an inverted trapezoidal structure on the photoresist film 2. For example, according to the evaporation pattern of the mask sheet to be prepared, partially exposing and developing the photoresist film 2 to obtain a slot 3 with an inverted trapezoidal structure in cross section. The slot mouth width of the inverted trapezoidal structure slot 3 is smaller than the width of the slot bottom. The specific shape is shown in FIG. 2 or FIG. 4, so that the foil film subsequently located in the slot 3 does not adhere to the foil film located on the photoresist film 2.

Step S3. A magnetic plate 4 is arranged on the other surface of the carrier 1, that is, a magnetic plate 4 is arranged on the side of the carrier 1 opposite to the photoresist film 2. The size of the magnetic plate 4 can fully cover the carrier 1, and a reinforcing rib 5 is adsorbed on the surface of the photoresist film 2 by utilizing the magnetism of the magnetic plate 4. The reinforcing rib 5 is made of soft magnetic material and can be attached to the surface of the photoresist film 2 under the magnetic attraction of the magnetic plate 4; the reinforcing rib 5 includes a frame and ribs arranged on the frame, the inner side wall of the frame is inclined outward from top to bottom, and the cross-section of the ribs is an inverted trapezoidal structure, that is, the upper side of the rib is longer than the lower side, so the guide angle θ of the top thereof is less than 90°, and preferably, the guide angle θ is 30°≤θ≤60°, so during evaporation, a continuous foil film (first vacuum-plated foil film) can be formed on the surface of the reinforcing rib 5, and the foil film is not connected to the foil film (second vacuum-plated foil film) located in the slot. In addition, the surface on which the reinforcing rib 5 is provided has a certain degree of roughness, and the rough surface facilitates the foil film to adhere thereto during subsequent evaporation, thereby improving the adhesion of the first vacuum-plated foil film 6 to the surface of the reinforcing rib 5. Since the reinforcing rib 5 has the function of supporting and unfolding the first vacuum-plated foil film, it is convenient for the subsequent transfer and fixation of the first vacuum-plated foil film, and can prevent the first vacuum-plated foil film from breaking during subsequent use.

Step S4. Forming a first vacuum-coated foil film 6 on the surface of the photoresist film 2 and the reinforcing rib 5 by a vacuum coating method (the first vacuum-coated foil film 6 is used as a mask in subsequent steps, so it can also be called a mask), and forming a second vacuum-coated foil film 7 in the slot 3, specifically: depositing the material on the photoresist film 2, the reinforcing rib 5 and the slot 3 by a physical vapor deposition method, and using the inverted trapezoidal structure of the slot 3 to separate the foil film deposited on the surface of the photoresist film 2 and the reinforcing rib 5 from the foil film deposited in the slot 3, wherein the foil film deposited on the photoresist film 2 and the reinforcing rib 5 is The foil film on the surface can form a continuous film sheet, which is defined as the first vacuum-plated foil film 6, and the foil films deposited in each slot 3 are independent and unconnected, which are defined as the second vacuum-plated foil film 7. Since the first vacuum-plated foil film 6 is not connected to the second vacuum-plated foil film 7, openings can be formed at the positions of the first vacuum-plated foil film 6 corresponding to the second vacuum-plated foil film 7, and due to the effect of deposition, these openings are expanded. At the same time, the distribution of these openings is the same as the pattern to be evaporated on the substrate, which is equivalent to forming an opening portion adapted to the evaporation pattern on the first vacuum-plated foil film 6.

Step S5. Remove the photoresist film 2, separate the reinforcing ribs 5 and the first vacuum-plated foil film 6 from the carrier 1 and the second vacuum-plated foil film 7, and obtain a mask sheet assembly 9. This step is specifically as follows: first remove the magnetic plate 4, and then immerse the carrier 1, the photoresist film 2, the reinforcing ribs 5, the first vacuum-plated foil film 6, and the second vacuum-plated foil film 7 that are superimposed on one another in a cleaning solution, which is a mixture of ethanolamine and dimethyl sulfoxide, which can slowly dissolve the photoresist film 2, and then separate the reinforcing ribs 5 and the first vacuum-plated foil film 6 from the carrier 1 and the second vacuum-plated foil film 7, and obtain a mask sheet assembly 9, which is composed of the reinforcing ribs 5 and the first vacuum-plated foil film 6.

Step S6. Transfer the mask sheet assembly 9 to the mask frame 8, and bind it to the mask frame 8 by welding to obtain a mask plate. In this step, the first vacuum-plated foil film (equivalent to the mask sheet) can be very conveniently transferred to the mask frame 8 by utilizing the supporting function of the reinforcing ribs 5. During the transfer process, no other auxiliary tools are required, and the first vacuum-plated foil film can be ensured not to be deformed, wrinkled, cracked, or broken, which is very convenient; in addition, when the mask sheet assembly 9 is not immediately welded to the mask frame 8 and is stored as a backup, the reinforcing ribs 5 can also keep the mask sheet in an unfolded state during storage.

It can be seen that the method for preparing the mask plate described in this embodiment forms a photoresist film 2 on the surface of the carrier plate 1 so as to form a specific pattern on the photoresist film 2 by means of photolithography. The specific pattern is the same as the evaporation pattern of the mask plate to be prepared, that is, it can make the mask plate have an opening adapted to the evaporation pattern. When the opening is applied to the substrate to evaporate the organic film, the steam can adhere to the surface of the substrate through the opening to form an organic film. At the same time, the slot 3 is set to an inverted trapezoidal structure, and its inclined edge can separate the formed first vacuum-plated foil film 6 and the second vacuum-plated foil film 7 from each other, and can make the first vacuum-plated foil film 6 form a bevel or a bevel with a curvature at the position corresponding to the slot 3, that is, the opening formed by the first vacuum-plated foil film 6 is expanded, so when it is applied to the evaporation of the substrate, a more uniform organic film can be formed. Furthermore, since the thickness of the mask sheet to be prepared is very thin, in order to prevent the mask sheet from wrinkling and cracking, and to facilitate the transfer of the mask sheet, a reinforcing rib 5 is also provided in the preparation method. The supporting effect of the reinforcing rib 5 can prevent the mask sheet from wrinkling and cracking after the first vacuum-plated foil film 6 is separated from the photoresist film 2, and the transfer of the mask sheet can be more convenient. In addition, in order to facilitate the attachment of the reinforcing rib 5 to the surface of the photoresist film 2, the reinforcing rib 5 is made of soft magnetic material. By setting a magnetic plate 4 on one side of the substrate, the reinforcing rib 5 can be attached to the surface of the photoresist film 2 by the magnetic attraction of the magnetic plate 4. When the magnetic plate 4 is withdrawn, the reinforcing plate can be easily detached from the surface of the photoresist film 2, which is convenient for separation.

In the above preparation method, in order to prevent the first vacuum-plated foil film 6 and the second vacuum-plated foil film 7 from sticking together, in addition to making the slot 3 an inverted trapezoidal structure, the thickness of the first vacuum-plated foil film 6 and the second vacuum-plated foil film 7 must be controlled. In this regard, in a preferred embodiment, the thickness of the first vacuum-plated foil film 6 and the second vacuum-plated foil film 7 is less than the depth of the slot 3, so the inclined wall of the slot 3 can be used to prevent the first vacuum-plated foil film 6 and the second vacuum-plated foil film 7 from forming a continuous shape. In the specific implementation process, the depth of the slot 3 can be set according to the thickness of the mask sheet to be prepared so that its depth is greater than the thickness of the first vacuum-plated foil film 6 and the second vacuum-plated foil film 7. Specifically, on the one hand, the thickness of the mask sheet needs to be selected according to factors such as pixel density, and on the other hand, the strength of the mask sheet must also be considered. Therefore, as a preferred embodiment, the thickness of the first vacuum-plated foil film 6 and the second vacuum-plated foil film 7 is 0.1-30μm, and at this time, the depth of the slot 3 is preferably>30μm. More preferably, the thickness of the first vacuum-plated foil film 6 and the second vacuum-plated foil film 7 is 10-15 μm, and the depth of the slot 3 should be greater than 15 μm.

Specifically, in step S4, the vacuum coating method is selected from one of magnetron sputtering, ion plating, electron beam evaporation and laser evaporation, and a first vacuum-coated foil film 6 can be deposited on the surface of the reinforcing rib 5 and the photoresist film 2, and a second vacuum-coated foil film 7 can be deposited in the slot 3.

In step S4, the material deposited by vacuum coating can be a combination of one or more of nickel-iron alloy, iron-cobalt-nickel alloy, iron-cobalt-samarium alloy, ceramic, glass, diamond, diamond-like carbon (DLC), or other materials with good thermal stability and mechanical strength. In the specific implementation process, it can be selected according to actual needs to meet the performance requirements of the mask. For example, the first vacuum-coated foil film 6 is composed of two materials, iron-nickel alloy and diamond. During vacuum coating, one of the materials can be deposited first, and then the other material can be deposited, or co-plating can be performed. It can be selected according to actual needs.

In the above-mentioned embodiment, when removing the photoresist film 2, the multiple hierarchical structures before demolding need to be placed in the cleaning liquid. However, since the photoresist film 2 is clamped between the carrier 1, the reinforcing ribs 5 and the first vacuum-plated foil film 6, the contact surface between the photoresist film 2 and the cleaning liquid is small, resulting in a long soaking time and low production efficiency. In this regard, in a preferred embodiment, as shown in FIG3, in order to better expose the photoresist film 2, the carrier 1 is set as a transparent carrier 1, and a stripping film 10 is also provided between the carrier 1 and the photoresist film 2. The stripping film 10 can separate the carrier 1 from the photoresist film 2 under the action of heat or laser, and then the carrier 1 can be very conveniently removed from the surface of the photoresist film 2, so that a larger area of the surface of the photoresist film 2 is exposed. During soaking, the contact area between the photoresist film 2 and the cleaning liquid can be greatly increased, the cleaning time can be shortened, and the cleaning efficiency can be improved. In the specific implementation process, the preparation method of the mask plate with a stripping film is shown in Figure 3. Before forming the photoresist film, the stripping film is first formed on the carrier plate, and then the photoresist film is formed on the stripping film; in addition, before removing the photoresist film, the stripping film is first separated from the photoresist film by laser irradiation or heating, and then other steps are performed.

In a preferred embodiment, the stripping film 10 is an amorphous gallium nitride film, an indium zinc nitride film or a thermal stripping film, and the carrier 1 can be separated from the photoresist film 2 by laser stripping technology or thermal stripping technology. Specifically, the thermal stripping film is a film with the brand name REVALPHA, which can separate the carrier 1 from the photoresist film 2 under the action of heat.

In addition, in the aforementioned embodiment, in order to ensure that the mask sheet is in a better unfolded state after being bound to the mask frame 8, in the step S6, the mask frame 8 is cooled before being bound, that is, the temperature of the mask frame 8 is lowered to shrink it, and after binding, the mask frame 8 is restored to room temperature. When heated, the frame has a certain degree of expansion, so that the mask sheet can be in a tensioned state and fully unfolded, so that the vapor deposition pattern can be more precise when used later.

The preparation method described in the above embodiment is to separate the photoresist film from the reinforcing ribs and the first vacuum-plated foil film by cleaning with a cleaning liquid. This method is time-consuming, but is suitable for the preparation of mask frames with thinner mask sheets. For the preparation of mask frames with a mask sheet thickness greater than or equal to 10 μm, a simpler preparation method can be used. Specifically, in another preferred embodiment, another mask plate preparation method is adopted, as shown in FIG5 , the preparation steps of the preparation method are basically the same as those of the preparation method of the aforementioned embodiment, except that: (1) in step S1, a transparent carrier is used as the carrier to facilitate laser transmission; (2) step S3 is: a layer of organic transparent adhesive film 11 is coated on the surface of the reinforcing rib, the organic transparent adhesive film 11 is an adhesive film that can be decomposed or melted under the action of a laser of a specific wavelength or/and a specific pulse width, such as a PI film or a PP film, and the reinforcing rib is attached to the photoresist film through the organic transparent adhesive film, so that the reinforcing rib can be fixed to the photoresist film without a magnetic plate; (3) step S5 is: by focusing the laser on the interface where the organic transparent adhesive film 11 contacts the reinforcing rib, and on the interface where the photoresist film contacts the first vacuum-plated foil film, the organic transparent adhesive film and part of the photoresist film are decomposed or melted by the action of the laser, so that the photoresist film is separated from the reinforcing rib and the first vacuum-plated foil film, and a mask plate assembly is obtained.

In this embodiment, the organic transparent adhesive film and the photoresist film can be separated from the reinforcing ribs and the first vacuum-plated foil film very quickly through the action of laser without the need for immersion and cleaning, which can greatly shorten the production time and improve production efficiency. Moreover, when the reinforcing ribs are attached to the photoresist film, the positioning can be more precise through the adhesion of the organic transparent adhesive film compared to the adsorption effect of the magnetic plate.

The second aspect of the present invention also provides a mask plate, which is prepared by the preparation method as described above, and the mask plate includes a mask frame 8 and a mask sheet assembly 9, and the mask sheet assembly 9 is welded to the mask frame 8. The mask sheet assembly 9 includes a reinforcing rib 5 and a mask sheet. The thickness of the mask sheet is 0.1 to 30 μm, preferably 10 to 15 μm, and is provided with a flared opening. When it is used in the manufacture of an OLED display screen, a uniform evaporated film can be formed on the substrate.

In summary, the mask plate preparation method provided by the present invention, through the photoresist film 2 with inverted trapezoidal grooves 3, can realize obtaining the first vacuum-coated foil film 6 with a flared opening through vacuum coating, and by attaching additional reinforcing ribs 5 on the photoresist film 2, the first vacuum-coated foil film 6 can always remain in an unfolded state during separation, transfer, and binding, and can prevent the mask sheet from wrinkling, deformation, and cracking, thereby better protecting the mask sheet.

In the description of the embodiments of the present invention, it should be noted that the terms "inside", "outside", "upper", "lower", "left", "right", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invented product is usually placed when in use, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the term "disposed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the claims attached to the present invention.

Claims (10)

1. A method for preparing a mask plate, characterized in that the method comprises the following steps: Step S1. forming a photoresist film on one surface of the carrier; Step S2. forming a groove having an inverted trapezoidal structure on the photoresist film; Step S3. Arrange a reinforcing rib on the surface of the photoresist film; the reinforcing rib comprises a frame and ribs arranged on the frame, the inner side wall of the frame is inclined outward from top to bottom, and the cross section of the rib is an inverted trapezoidal structure; the surface of the reinforcing rib has a certain degree of roughness, and the rough surface facilitates the foil film to be attached thereto during subsequent evaporation; Step S4. forming a first vacuum-coated foil film on the surface of the photoresist film and the reinforcing ribs by a vacuum coating method, and forming a second vacuum-coated foil film in the slots, and utilizing the inverted trapezoidal structure of the slots to separate the first vacuum-coated foil film deposited on the surface of the photoresist film and the reinforcing ribs from the second vacuum-coated foil film deposited in the slots; Step S5. removing the photoresist film, separating the reinforcing ribs and the first vacuum-plated foil film from the carrier and the second vacuum-plated foil film, and obtaining a mask sheet assembly, wherein the mask sheet assembly is composed of the reinforcing ribs and the first vacuum-plated foil film; Step S6: Transfer the mask sheet assembly to the mask frame and bind it to the mask frame to obtain a mask plate. 2. The method for preparing a mask plate according to claim 1, characterized in that, in the step S3, a magnetic plate is firstly arranged on the surface of the carrier plate opposite to the photoresist film, and a reinforcing rib is adsorbed on the surface of the photoresist film by utilizing the magnetism of the magnetic plate. 3 . The method for preparing a mask according to claim 1 , wherein in step S3 , a layer of organic transparent adhesive film is coated on the surface of the reinforcing rib, and the reinforcing rib is attached to the photoresist film through the organic transparent adhesive film. 4. The method for preparing a mask plate according to claim 1, characterized in that the thickness of the first vacuum-coated foil film and the second vacuum-coated foil film is less than the depth of the slot, and the first vacuum-coated foil film is not connected to the second vacuum-coated foil film. 5 . The method for preparing a mask according to claim 1 , wherein in step S4 , a vacuum coating method is selected from magnetron sputtering, ion plating, electron beam evaporation and laser evaporation. 6. The method for preparing a mask plate according to claim 1 is characterized in that the material of the first vacuum-plated foil film and the second vacuum-plated foil film is selected from a combination of one or more of nickel-iron alloy, iron-cobalt-nickel alloy, iron-cobalt-samarium alloy, ceramic, glass, diamond, and diamond-like carbon. 7 . The method for preparing a mask plate according to claim 1 , wherein the carrier plate is a transparent carrier plate, and a stripping film is provided between the carrier plate and the photoresist film. 8 . The method for preparing a mask according to claim 7 , wherein the stripping film is an amorphous gallium nitride film or an indium zinc nitride film, or a thermal stripping film. 9 . The method for preparing a mask plate according to claim 1 , wherein in the step S6 , the mask frame is subjected to a cooling process before being bound. 10 . A mask plate, characterized in that it is prepared by the method according to any one of claims 1 to 9 , the mask plate comprises a mask frame and a mask sheet, and the thickness of the mask sheet is 0.1 to 30 μm.