High-precision mask plate and preparation method thereof

Abstract

The application relates to the mask preparation technical field, and discloses a high-precision mask and a preparation method thereof, which comprises the following steps: preparing a separation layer on a carrier plate; preparing a mask foil film on the separation layer by adopting a vacuum coating method; preparing a second photoresist film layer on the mask foil film and performing a pattern photoetching treatment on the second photoresist film layer to form a photoresist pattern film; performing etching treatment on the mask foil film, and pre-fixing the obtained etching mask on a mask frame; separating the etching mask from the carrier plate; and secondarily fixing the separated etching mask on the mask frame by adopting a laser welding method to prepare the high-precision mask. The method can realize precise etching on the mask foil film which is thin and has better strength, thereby preparing the high-precision mask. The etching mask and the mask frame are bound in the form of an assembly, so that the prepared mask is not prone to wrinkling or breaking during separation and conveying.

Description

Technical Field

[0001] This invention relates to the field of mask fabrication technology, and in particular to a high-precision mask and its fabrication method. Background Technology

[0002] OLED displays have many advantages over LCD displays, such as better color reproduction, shorter response time, better low-temperature performance, and can be made thinner, lighter, and more flexible. Currently, OLED displays are widely used in mobile phones, watches, and other displays.

[0003] OLED display manufacturing vapor deposition machines include a light-emitting layer deposition chamber, which houses a precision mask (FMM) to shield other pixels during deposition. The FMM allows for the deposition of RGB light-emitting organic materials onto the RGB pixel points of the substrate. Currently, mass-produced precision masks are typically 30-50 μm thick. These masks are usually created using wet etching to create holes through which material vapor passes during deposition. Due to the isotropic nature of wet etching, thicker foils are difficult to make the holes smaller to achieve higher resolution. Furthermore, because some organic materials have a certain evaporation angle when deposited onto the substrate, the film often needs to be very thin to ensure uniform filling of the substrate pixels. Higher pixel resolution requires a thinner mask, but thinner masks are weaker and more prone to wrinkling or cracking, causing significant problems for bonding, transport, and deposition.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a high-precision mask and its preparation method, which aims to solve the problem that existing mask preparation methods are difficult to produce masks with thinness and high precision.

[0006] The technical solution of the present invention is as follows:

[0007] A method for preparing a high-precision photomask, comprising the following steps:

[0008] A separation layer is prepared on a carrier substrate. The separation layer is one of a pyrolytic adhesive layer, a sacrificial layer, a first photoresist layer, and a pixel confinement layer, or the separation layer is a combination layer consisting of a sacrificial layer and a pixel confinement layer stacked sequentially.

[0009] A mask foil is prepared on the separation layer using vacuum deposition.

[0010] A second photoresist film layer is prepared on the mask foil, and a pattern photolithography process is performed on the second photoresist film layer to form a photoresist pattern film.

[0011] The photoresist pattern film is used to etch the mask foil, or both the mask film and the separation layer are etched to obtain an etched mask.

[0012] The etching mask is pre-fixed to the mask frame by means of adhesive or laser welding;

[0013] The etching mask is separated from the carrier plate by heating or laser scanning.

[0014] The separated etching mask is then fixed onto the mask frame again by laser welding to obtain the high-precision mask plate.

[0015] The method for preparing the high-precision photomask, wherein when the carrier plate is a transparent carrier plate and the separation layer is a sacrificial layer, includes the following steps after forming the photoresist pattern film:

[0016] Based on the photoresist pattern film, the mask foil film is subjected to non-penetrating etching to obtain a partially etched mask.

[0017] The etched mask sheet is fixed to the mask frame by laser welding.

[0018] The sacrificial layer is removed by laser scanning, thereby separating the etched mask from the transparent substrate.

[0019] Laser drilling is performed on the un-etched side of the partial etched mask, aligned with the etched position, to form pixel-limiting holes on the partial etched mask. The diameter of the laser-drilled holes is smaller than the diameter of the etched holes, thereby producing the high-precision mask.

[0020] The method for preparing the high-precision photomask, wherein when the carrier plate is a transparent carrier plate and the separation layer is a pixel confinement film layer, includes the following steps after forming the photoresist pattern film:

[0021] Based on the photoresist pattern film, the mask foil is subjected to a through-etching process to obtain an etched mask.

[0022] The etching mask is fixed to the mask frame by laser welding.

[0023] Laser drilling is performed on the pixel confinement film layer through a transparent substrate. The position of the laser drilling corresponds to the etching position on the etching mask, and the diameter of the laser-drilled hole is smaller than the diameter of the hole formed by etching on the etching mask.

[0024] A portion of the pixel-restricting film is removed by laser scanning through a transparent substrate, thereby separating the transparent substrate from the remaining pixel-restricting film and the etching mask, thus producing the high-precision mask.

[0025] The method for preparing the high-precision photomask includes the following steps after forming the photoresist pattern film, when the carrier plate is a transparent carrier plate and the separation layer is a composite layer consisting of a sacrificial layer and a pixel confinement film layer stacked sequentially:

[0026] Based on the photoresist pattern film, the mask foil is subjected to a through-etching process to obtain an etched mask.

[0027] The etching mask is fixed to the mask frame by laser welding.

[0028] The sacrificial layer is removed by laser scanning, which separates the etching mask and pixel confinement film from the transparent substrate.

[0029] Laser drilling is performed directly on the pixel-restricting film layer. The location of the laser drilling corresponds to the etching location on the etching mask, and the diameter of the laser-drilled hole is smaller than the diameter of the hole formed by etching on the etching mask, thereby producing the high-precision mask.

[0030] The method for preparing the high-precision photomask includes the following steps after forming the photoresist pattern film when the carrier plate is a non-transparent carrier plate and the separation layer is a first photoresist film layer:

[0031] Based on the photoresist pattern film, the mask foil is subjected to penetration etching, and the photoresist pattern film is removed to obtain an etched mask.

[0032] The etching mask is placed on the mask frame and laser-welded from the side to pre-fix the etching mask on the mask frame.

[0033] The first photoresist film layer is removed by wet etching, so that the etching mask is separated from the non-transparent carrier plate;

[0034] The separated etching mask is then fixed onto the mask frame again by laser welding to obtain the high-precision mask plate.

[0035] The method for preparing the high-precision photomask, wherein when the carrier plate is a non-transparent carrier plate and the separation layer is a first photoresist film layer, further includes the following steps after forming the photoresist pattern film:

[0036] Based on the photoresist pattern film, the mask foil is subjected to penetration etching, and the photoresist pattern film is removed to obtain an etched mask.

[0037] The edge portion of the photoresist pattern film is etched to expose the edge portion of the etching mask.

[0038] The edge portion of the etching mask is placed on the mask frame, and the etching mask is laser welded from the side to pre-fix the edge portion of the etching mask on the mask frame.

[0039] The remaining photoresist pattern film and the first photoresist film layer are removed by wet etching, so that the etching mask is separated from the non-transparent carrier plate.

[0040] The separated etching mask is then fixed onto the mask frame again by laser welding to obtain the high-precision mask plate.

[0041] The method for preparing the high-precision mask plate, wherein the thickness of the mask foil is 0.3μm-30μm.

[0042] The method for preparing the high-precision mask plate, wherein the material of the mask foil is one of nickel-iron alloy, nickel-iron-cobalt alloy, ceramic, glass, diamond, and diamond-like carbon; and the material of the carrier plate is glass, metal, ceramic, or plastic.

[0043] The method for preparing the high-precision mask includes vacuum deposition methods such as PVD, CVD, and ion plating.

[0044] A high-precision photomask, wherein it is prepared by any of the high-precision photomask preparation methods of the present invention.

[0045] Beneficial effects: After fabricating a separation layer on a carrier plate, the present invention uses vacuum deposition to further prepare a mask foil on the separation layer. The vacuum deposition method allows for control over the material, shape, strength, and thickness of the mask foil, enabling precision etching on a thinner mask foil with better strength, thereby producing a high-precision mask. Then, the etching mask with better strength is bound to the mask frame in the form of a component. The mask produced in this way is less prone to wrinkling or breaking during separation and transportation, greatly improving the production yield of high-precision mask. Attached Figure Description

[0046] Figure 1 This invention provides a flowchart of a method for preparing a high-precision photomask.

[0047] Figure 2 This is a schematic diagram of the fabrication of the high-precision mask plate in Embodiment 1 of the present invention.

[0048] Figure 3 This is a schematic diagram of the fabrication of the high-precision mask plate in Embodiment 2 of the present invention.

[0049] Figure 4 This is a schematic diagram of the fabrication of the high-precision mask plate in Embodiment 3 of the present invention.

[0050] Figure 5 This is a schematic diagram illustrating the fabrication of the high-precision mask in Embodiment 4 of the present invention.

[0051] Figure 6 This is a schematic diagram of the fabrication of the high-precision mask plate in Embodiment 5 of the present invention.

[0052] Figure 7 This is a schematic diagram illustrating the fabrication of the high-precision mask in Embodiment 6 of the present invention.

[0053] Figure 8 This is a schematic diagram of the fabrication of the high-precision mask plate in Embodiment 7 of the present invention.

[0054] Figure 9 This is a schematic diagram of the fabrication of the high-precision mask plate in Embodiment 8 of the present invention.

[0055] Figure 10 This is a schematic diagram illustrating the fabrication of the high-precision mask in Embodiment 9 of the present invention.

[0056] Figure 11 This is a schematic diagram of the fabrication of the high-precision mask in Embodiment 10 of the present invention.

[0057] Figure 12 This is a schematic diagram of the fabrication of the high-precision mask plate in Embodiment 11 of the present invention. Detailed Implementation

[0058] This invention provides a high-precision photomask and its preparation method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0059] Please see Figure 1 , Figure 1 A flowchart of a method for fabricating a high-precision photomask provided by the present invention is shown in the figure, which includes the following steps:

[0060] S10. Prepare a separation layer on a carrier plate. The separation layer is one of a pyrolytic adhesive layer, a sacrificial layer, a first photoresist layer, and a pixel confinement layer, or the separation layer is a combination layer composed of a sacrificial layer and a pixel confinement layer stacked sequentially.

[0061] S20. A mask foil is prepared on the separation layer by vacuum deposition.

[0062] S30. A second photoresist film layer is prepared on the mask foil, and a pattern photolithography process is performed on the second photoresist film layer to form a photoresist pattern film.

[0063] S40. Based on the photoresist pattern film, the mask foil is etched or both the mask film and the separation layer are etched to obtain an etched mask.

[0064] S50. The etching mask is pre-fixed onto the mask frame by means of adhesive or laser welding;

[0065] S60. Separate the etching mask from the carrier plate by heating or laser scanning;

[0066] S70. The separated etching mask is fixed onto the mask frame again by laser welding to obtain the high-precision mask plate.

[0067] Specifically, the separation layer can typically be prepared on a carrier substrate using coating methods such as spin coating, slot coating, spraying, brushing, dip coating, or vacuum deposition. The separation layer can be categorized into a pyrolytic adhesive layer, a sacrificial layer, a first photoresist film layer, and a pixel confinement film layer based on its function and material. The pyrolytic adhesive layer is primarily made of polypropylene, polyethylene, and some additives, and can be cured by heating or ultraviolet irradiation to form the pyrolytic adhesive layer. The sacrificial layer and pixel confinement film layer can be made of polymers, metals, or inorganic materials. Polymers can be polyimide, metals can be molybdenum, aluminum, copper, silver, gold, etc., and inorganic materials can be silicon dioxide or silicon nitride, etc. The first photoresist film layer is typically made of a photosensitive organic polymer.

[0068] This invention employs vacuum deposition to prepare a mask foil on a separation layer. The material of the mask foil can be one of, but is not limited to, nickel-iron alloy, nickel-iron-cobalt alloy, ceramic, glass, diamond, and diamond-like carbon. The vacuum deposition method in this invention includes PVD, CVD, and ion plating. PVD is a physical deposition method that vaporizes a material source into atoms or molecules and then re-condenses them into a thin film in a vacuum or a specific atmosphere. The advantages of PVD are that it can prepare films with high purity, high adhesion, and low porosity, and it has a high deposition rate. CVD is a chemical vapor deposition method that introduces a gas containing film components into a reaction chamber, where a chemical reaction occurs on the substrate surface to form a film. The advantages of CVD are that it can prepare films with dense structure, strong adhesion, and uniform composition, and it can be prepared at low temperatures. Furthermore, CVD allows control of the film's composition and properties by adjusting the reaction gas and reaction conditions. Ion plating is a physical-chemical vapor deposition method. It involves introducing gas into a reaction chamber, where it is ionized into ions under an electric field. These ions are then accelerated towards the substrate surface and deposited as a thin film. The advantages of ion plating include the ability to produce dense, strongly adhered, and uniformly composed films, and it can be performed at low temperatures. Furthermore, the composition and properties of the film can be controlled by adjusting the electric field and reaction conditions. This invention can utilize any of the three vacuum deposition methods mentioned above to fabricate mask foils, depending on the materials and conditions. Vacuum deposition allows for control over the material, shape, strength, and thickness of the mask foil, enabling precision etching on thinner, stronger mask foils to produce high-precision masks. The high-strength etching mask is then bonded to the mask frame as an assembly. This method makes the mask less prone to wrinkling or breakage during separation and transport, significantly improving the production yield of high-precision masks. In this invention, the thickness of the mask foil can be 0.3μm-30μm.

[0069] In this invention, the carrier plate can be a transparent carrier plate or a non-transparent carrier plate. The transparent carrier plate can be made of transparent glass, sapphire wafers, etc., while the non-transparent carrier plate can be made of silicon wafers, germanium wafers, metals, ceramics, or plastics, etc., but is not limited thereto.

[0070] In some embodiments, a high-precision mask is also provided, which is prepared by the above-described high-precision mask preparation method of the present invention.

[0071] The following specific embodiments further illustrate the method for preparing a high-precision photomask according to the present invention:

[0072] Example 1

[0073] A method for preparing a high-precision photomask, such as... Figure 2 As shown, it includes the following steps:

[0074] 1. First, clean the non-transparent substrate 10 to remove dirt, grease and other impurities from the surface. Then, apply the pyrolytic adhesive solution to the non-transparent substrate by spraying and cure it by heating or ultraviolet irradiation to form the pyrolytic adhesive layer 20.

[0075] 2. A nickel-iron alloy layer is deposited on the pyrolytic adhesive layer 20 by vacuum deposition to serve as a mask foil 30;

[0076] 3. A photoresist film layer 40 is prepared on the photomask foil 30 and a pattern photolithography process is performed on the photoresist film layer to form a photoresist pattern film 41;

[0077] 4. Based on the photoresist pattern film 41, the mask foil 30 and the pyrolytic adhesive layer 20 are etched to obtain the etched mask 31. In this embodiment, the etching process can be wet etching or dry etching. Dry etching mainly refers to the method of thin film etching using plasma under high vacuum conditions. It mainly utilizes the combined effect of physical collision and chemical reaction to achieve material etching. Its advantages include anisotropic etching, high precision, low damage, and good uniformity over a large area. Wet etching, on the other hand, uses a chemical solution to react with the thin film material, removing unwanted thin film material through corrosion and dissolution. Its advantages include simple operation, low cost, and low equipment requirements.

[0078] 5. Apply adhesive 51 to the mask frame 50 and fix the edge of the etching mask 31 to the mask frame with the adhesive 51 to facilitate the subsequent separation of the etching mask from the carrier plate.

[0079] 6. The pyrolytic adhesive layer is softened by heating the carrier plate with heater 60, thereby achieving the separation of the etching mask 31 from the carrier plate 10;

[0080] 7. Laser welding is performed on the contact area between the etching mask and the mask frame to fix the etching mask onto the mask frame for a second time, thereby producing the high-precision mask plate.

[0081] The high-precision mask prepared in this embodiment has a thickness of 0.3μm-30μm and its precision can reach submicron.

[0082] Example 2

[0083] The method for preparing the high-precision mask provided in Example 2 is as follows: Figure 3 As shown, the preparation methods of Example 2 and Example 1 are basically the same, with only the following two differences:

[0084] In step 4, the photoresist pattern film 41 is used to etch only the mask foil 30 without etching the pyrolytic adhesive layer, thus obtaining the etched mask 31. In this embodiment, the etching process can also be selected as wet etching or dry etching.

[0085] In step 5, it is not necessary to apply adhesive to the mask frame 50. The edge of the etching mask 31 can be placed directly on the mask frame, and then the contact area between the etching mask and the mask frame is laser welded from the side position 70 to achieve pre-fixation of the etching mask and the mask frame, which facilitates the subsequent separation of the etching mask and the carrier plate.

[0086] The high-precision mask prepared in this embodiment has a thickness of 0.3μm-30μm and its precision can reach submicron.

[0087] Example 3

[0088] The method for preparing the high-precision mask provided in Example 3 is as follows: Figure 4 As shown, the preparation method of Example 4 is basically the same as that of Example 1, with only the following three differences:

[0089] In step 1, this embodiment uses a transparent carrier plate;

[0090] In step 5, it is not necessary to apply adhesive to the mask frame 50. The edge of the etching mask 31 can be placed directly on the mask frame. Then, the contact area between the etching mask and the mask frame is laser welded directly from above the transparent carrier plate to fix the etching mask and the mask frame, which facilitates the subsequent separation of the etching mask and the carrier plate.

[0091] The secondary laser welding process in step 7 is not required.

[0092] The high-precision mask prepared in this embodiment has a thickness of 0.3μm-30μm and its precision can reach submicron.

[0093] Example 4

[0094] The method for preparing the high-precision mask provided in Example 4 is as follows: Figure 5 As shown, the preparation method of Example 5 is basically the same as that of Example 1, with only the following four differences:

[0095] In step 1, the transparent carrier plate 10 is first cleaned to remove dirt, grease and other impurities from the surface. Then, a sacrificial layer 20 is prepared on the non-transparent carrier plate by spraying.

[0096] In step 5, it is not necessary to apply adhesive to the mask frame 50. The edge of the etching mask 31 can be placed directly on the mask frame. Then, the contact area between the etching mask and the mask frame is laser welded directly from above the transparent carrier plate to fix the etching mask and the mask frame, which facilitates the subsequent separation of the etching mask and the carrier plate.

[0097] In step 6, the sacrificial layer is irradiated by laser scanning to separate the etching mask 31 from the transparent carrier plate 10.

[0098] The secondary laser welding process in step 7 is not required.

[0099] The high-precision mask prepared in this embodiment has a thickness of 0.3μm-30μm and its precision can reach submicron.

[0100] Example 5

[0101] A method for fabricating a high-resolution beveled mask, such as... Figure 6 As shown, it includes the following steps:

[0102] 1. First, the transparent carrier plate 10 is cleaned to remove dirt, grease and other impurities from the surface. Then, a sacrificial layer 20 is prepared on the transparent carrier plate by spraying.

[0103] 2. A nickel-iron alloy layer is deposited on the sacrificial layer 20 by vacuum deposition to serve as a mask foil 30;

[0104] 3. A photoresist film layer 40 is prepared on the photomask foil 30 and a pattern photolithography process is performed on the photoresist film layer to form a photoresist pattern film 41;

[0105] 4. Based on the photoresist pattern film 41, the mask foil 30 and the sacrificial layer 20 are etched to obtain the etched mask 31. Since this embodiment requires the mask foil 30 to be etched into a hole structure with chamfered corners, this embodiment preferably uses dry etching. By adjusting the power or speed of the dry etching, the mask foil is etched into a single etched mask 31 with chamfered corner hole structure. This embodiment uses a method of uniformly decreasing the power from high to low to obtain the desired result. Figure 6 The etching mask shown has a chamfered hole structure.

[0106] 5. Place the edge of the first etching mask 31 directly on the mask frame 50, and then perform laser welding on the contact area between the etching mask 31 and the mask frame 50 directly from above the transparent carrier plate 10 to fix the etching mask to the mask frame, which facilitates the subsequent separation of the etching mask from the carrier plate.

[0107] 6. The sacrificial layer 20 is irradiated by laser scanning to separate the etching mask 31 from the transparent carrier plate 10;

[0108] 7. Perform a secondary etching process on the unetched side of the etching mask, and form a chamfer on the other side of the etching mask to form a secondary etching mask 32. The secondary etching process can be plasma dry etching of the entire etching mask. After etching, the high-resolution chamfer mask is obtained.

[0109] The high-precision mask prepared in this embodiment has a thickness of 0.3μm-30μm and its precision can reach submicron.

[0110] Example 6

[0111] A method for preparing a high-precision photomask, such as... Figure 7 As shown, it includes the following steps:

[0112] 1. First, the transparent carrier plate 10 is cleaned to remove dirt, grease and other impurities from the surface. Then, a sacrificial layer 20 is prepared on the transparent carrier plate by spraying.

[0113] 2. A nickel-iron alloy layer is deposited on the sacrificial layer 20 by vacuum deposition to serve as a mask foil 30;

[0114] 3. A photoresist film layer 40 is prepared on the photomask foil 30 and a pattern photolithography process is performed on the photoresist film layer to form a photoresist pattern film 41;

[0115] 4. Based on the photoresist pattern film 41, the mask foil 30 is subjected to non-penetrating etching to obtain the etched mask 31. In this embodiment, the etching process can be selected as wet etching or dry etching. By controlling the etching time, the desired result can be obtained. Figure 7 The etched mask shown is not fully penetrated. To facilitate subsequent laser drilling or secondary etching, the secondary etching process is the same as the first etching process, and will not be described again here. In this embodiment, the etched thickness of the etched mask is greater than 1 / 2 of the total thickness of the etched mask, preferably 2 / 3 to 9 / 10 of the total thickness of the etched mask.

[0116] 5. Place the edge of the etching mask 31 directly on the mask frame, and then perform laser welding on the contact area between the etching mask and the mask frame directly from above the transparent carrier plate to fix the etching mask and the mask frame, which facilitates the subsequent separation of the etching mask and the carrier plate.

[0117] 6. The sacrificial layer is irradiated by laser scanning to separate the etching mask 31 from the transparent carrier plate 10;

[0118] 7. The unetched side of the etching mask is aligned with the etching position and subjected to laser drilling or secondary etching to form a pixel limiting hole 21 on the etching mask. The diameter of the laser-drilled hole is smaller than the diameter of the etched hole, thereby obtaining the high-precision mask.

[0119] The effective thickness of the high-precision mask substrate side obtained in this embodiment can be 0.3μm-15μm, and its accuracy can reach micrometer or submicrometer.

[0120] Example 7

[0121] A method for preparing a high-precision photomask, such as... Figure 8 As shown, it includes the following steps:

[0122] 1. First, the transparent substrate 10 is cleaned to remove dirt, grease and other impurities from the surface. Then, a pixel confinement film layer 20 is prepared on the transparent substrate by spraying.

[0123] 2. A nickel-iron alloy layer is deposited on the pyrolytic adhesive layer 20 by vacuum deposition to serve as a mask foil 30;

[0124] 3. A photoresist film layer 40 is prepared on the photomask foil 30 and a pattern photolithography process is performed on the photoresist film layer to form a photoresist pattern film 41;

[0125] 4. Based on the photoresist pattern film 41, the mask foil 30 is etched to obtain the etched mask 31. In this embodiment, the etching process can be wet etching or dry etching.

[0126] 5. Place the edge of the etching mask 31 directly on the mask frame, and then perform laser welding on the contact area between the etching mask and the mask frame directly from above the transparent carrier plate to fix the etching mask and the mask frame, which facilitates the subsequent separation of the etching mask and the carrier plate.

[0127] 6. Directly through the transparent carrier plate 10, perform laser drilling or secondary etching on the pixel restriction film layer 20 at the position corresponding to the quasi-etching position of the etching mask to form a pixel restriction hole 21 on the pixel restriction film layer. The diameter of the laser-drilled hole is smaller than the diameter of the hole formed by etching on the etching mask.

[0128] 7. A portion of the pixel-restricting film is removed by laser scanning through a transparent substrate, thereby separating the transparent substrate from the remaining pixel-restricting film and the etching mask, thus obtaining the high-precision mask.

[0129] The high-precision mask prepared in this embodiment has a thickness of 0.3μm-15μm, and its precision can reach micrometer or submicrometer.

[0130] Example 8

[0131] A method for preparing a high-precision photomask, such as... Figure 9 As shown, it includes the following steps:

[0132] 1. First, the transparent carrier plate 10 is cleaned to remove dirt, grease and other impurities from the surface. Then, a sacrificial layer 20 is prepared on the transparent carrier plate by spraying.

[0133] 2. A pixel-restricting film layer 201 is prepared on the sacrificial layer 20 by spraying.

[0134] 2. A nickel-iron alloy layer is deposited on the pixel confinement film layer 201 by vacuum deposition to serve as a mask foil 30;

[0135] 3. A photoresist film layer 40 is prepared on the photomask foil 30 and a pattern photolithography process is performed on the photoresist film layer to form a photoresist pattern film 41;

[0136] 4. Based on the photoresist pattern film 41, the mask foil 30 is etched to obtain the etched mask 31. In this embodiment, the etching process can be wet etching or dry etching.

[0137] 5. Place the edge of the etching mask 31 directly on the mask frame 50, and then perform laser welding on the contact area between the etching mask and the mask frame directly from above the transparent carrier plate to fix the etching mask and the mask frame, which facilitates the subsequent separation of the etching mask and the carrier plate.

[0138] 6. The sacrificial layer 20 is removed by laser scanning, so that the etching mask 41 and the pixel confinement film 201 are separated from the transparent carrier plate 10;

[0139] 7. Directly perform laser drilling or secondary etching on the pixel limiting film layer 201 at the position corresponding to the quasi-etching position of the etching mask to form a pixel limiting hole 21 on the pixel limiting film layer. The diameter of the laser-drilled hole is smaller than the diameter of the hole formed by etching on the etching mask, thereby obtaining the high-precision mask.

[0140] The high-precision mask prepared in this embodiment has a thickness of 0.3μm-15μm, and its precision can reach micrometer or submicrometer.

[0141] Example 9

[0142] The method for preparing the high-precision mask provided in Example 9 is as follows: Figure 10As shown, the preparation method of this embodiment 9 is basically the same as that of embodiment 7. The only difference is that in this embodiment 9, after the transparent carrier plate, the etching mask and the pixel confinement film are separated, the pixel confinement film is directly perforated to obtain the high-precision mask.

[0143] The high-precision mask prepared in this embodiment has a thickness of 0.3μm-15μm, and its precision can reach micrometer or submicrometer.

[0144] Example 10

[0145] A method for preparing a high-precision photomask, such as... Figure 11 As shown, it includes the following steps:

[0146] 1. First, the non-transparent substrate 10 is cleaned to remove dirt, grease and other impurities from the surface. Then, the first photoresist film layer 20 is prepared on the non-transparent substrate by spraying.

[0147] 2. A nickel-iron alloy layer is deposited on the first photoresist film layer 20 by vacuum deposition to serve as a mask foil 30;

[0148] 3. A second photoresist film layer 40 is prepared on the mask foil 30, and a pattern photolithography process is performed on the second photoresist film layer to form a photoresist pattern film 41;

[0149] 4. Based on the photoresist pattern film 41, the mask foil 30 is etched to obtain the etched mask 31. In this embodiment, the etching process can be wet etching or dry etching.

[0150] 5. The photoresist pattern film 41 is removed by wet etching or dry etching.

[0151] 6. Place the edge of the etching mask 31 directly on the mask frame, and then perform laser welding on the contact area between the etching mask and the mask frame from the side position 70 to achieve pre-fixation of the etching mask and the mask frame, which facilitates the subsequent separation of the etching mask and the carrier plate.

[0152] 7. The first photoresist film layer 20 is removed by wet etching, thereby separating the etching mask 31 from the carrier plate 10.

[0153] 8. Laser welding is performed on the contact area between the etching mask and the mask frame to fix the etching mask onto the mask frame for a second time, thereby producing the high-precision mask plate.

[0154] The high-precision mask prepared in this embodiment has a thickness of 0.3μm-30μm and its precision can reach the submicron level.

[0155] Example 11

[0156] The method for preparing the high-precision mask provided in Example 11 is as follows: Figure 12 As shown, the preparation methods of Example 2 and Example 1 are basically the same, with only the following two differences:

[0157] In this embodiment, after etching the mask foil 30, the photoresist pattern film 41 is not completely removed. Instead, only the edge of the photoresist pattern film is removed to expose the edge of the etching mask. After the pre-fixation of the etching mask and the mask frame is completed, wet etching is directly used to remove the remaining photoresist pattern film and the first photoresist film layer 20.

[0158] The high-precision mask prepared in this embodiment has a thickness of 0.3μm-30μm and its precision can reach the submicron level.

[0159] In summary, this invention involves fabricating a separation layer on a carrier substrate and then using vacuum deposition to further prepare a mask foil on the separation layer. Vacuum deposition allows for control over the material, shape, strength, and thickness of the mask foil, enabling precise etching on a thinner, stronger mask foil to produce a high-precision mask. Subsequently, the strong etching mask is bonded to the mask frame as a component. This method ensures that the resulting mask is less prone to wrinkling or breakage during separation and transport, significantly improving the production yield of high-precision mask panels.

[0160] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing a high-precision photomask, characterized in that, Including the following steps: A separation layer is prepared on a transparent substrate, and the separation layer is a composite layer consisting of a sacrificial layer and a pixel confinement film layer stacked sequentially. A mask foil is prepared on the separation layer by vacuum deposition. The material of the mask foil is one of nickel-iron alloy, nickel-iron-cobalt alloy, ceramic, glass, diamond, and diamond-like carbon. The thickness of the mask foil is 0.3μm-15μm. A second photoresist film layer is prepared on the mask foil, and a pattern photolithography process is performed on the second photoresist film layer to form a photoresist pattern film. Based on the photoresist pattern film, the mask foil is subjected to a through-etching process to obtain an etched mask. The etching mask is fixed to the mask frame by laser welding. The sacrificial layer is removed by laser scanning, which separates the etching mask and pixel confinement film from the transparent substrate. Laser drilling is performed directly on the pixel-restricting film layer. The location of the laser drilling corresponds to the etching location on the etching mask, and the diameter of the laser-drilled hole is smaller than the diameter of the hole formed by etching on the etching mask, thereby producing the high-precision mask.

2. The method for preparing the high-precision photomask according to claim 1, characterized in that, The vacuum coating method is PVD, CVD, or ion plating.

3. A high-precision photomask, characterized in that, It is prepared by the method described in any one of claims 1-2 for the preparation of high-precision photomasks.

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