Mask plate as well as preparation method and processing equipment thereof

Abstract

The invention discloses a mask plate and a preparation method and processing equipment thereof, the mask plate comprises a base material layer and a metal coating, the base material layer is doped with graphene, and the metal coating is arranged on at least part of the surface of the base material layer. The invention aims to provide the mask plate with good mechanical properties, the mask plate is thin, the mechanical properties are good, higher PPI can be realized, the sagging amount of the mask plate in the use process is reduced, the installation is convenient, and the mask plate is prevented from being scratched or damaged.

Description

Technical Field

[0001] The present invention relates to the technical field of FMM evaporation, and in particular to a mask plate and a preparation method thereof, and processing equipment using the mask plate. Background Art

[0002] FMM stands for Fine Metal Mask, and its main material is metal or metal plus resin. The main function of the mask is to provide a shielding effect for evaporation, so that the material can be deposited in a fixed position.

[0003] Organic Light Emitting Diode (OLED) display technology has been widely used in mobile phones, televisions, and automotive fields due to its many advantages such as self-luminescence, wide color gamut, and flexible display. Due to the special application scenarios of VR and AR technologies, the display screen is required to have higher resolution and smaller size. In order to achieve high resolution, the existing micro-OLED technology uses white light OLED with color filter technology to achieve color display. This technology can avoid the use of FMM in the OLED evaporation section and realize color display by photolithography patterning RGB primary color filters. However, the color filter will lose about 80% of the brightness of the sub-pixel, and the existing white light OLED device adopts a tandem structure, which increases the overall voltage and power consumption of the device, and is also accompanied by some lateral leakage and other non-brightness phenomena. In order to meet the high-brightness, low-power OLED micro-display screens required by future VR and AR, the technology of directly depositing RGB primary colors using FMM will also be one of the technical routes of micro-OLED.

[0004] In the related art, the metal mask made of invar alloy is limited by the thickness of the raw materials and the processing technology, and the opening is difficult to reach the size required by the micro display. The opening size of the fine mask (FMM) can be achieved by etching technology to be less than 10um, but in the process of making the mask, semiconductor exposure, development, and etching technology are required, the process flow is complicated, the product cost is high, and the yield is low. Summary of the invention

[0005] The main purpose of the present invention is to provide a mask plate and its preparation method and processing equipment, aiming to provide a mask plate with good mechanical properties. The mask plate is not only thin in thickness, but also has good mechanical properties, can achieve a higher PPI, and at the same time reduce the sagging amount of the mask plate during use, facilitate installation, and avoid scratches or damage.

[0006] To achieve the above object, the present invention provides a mask, the mask comprising:

[0007] a substrate layer, the substrate layer being doped with graphene; and

[0008] A metal coating layer is disposed on at least a portion of the surface of the substrate layer.

[0009] In one embodiment, the substrate layer has a first surface and a second surface disposed opposite to each other, and the metal coating includes a first metal coating and a second metal coating, wherein the first metal coating is disposed on the first surface and the second metal coating is disposed on the second surface.

[0010] In one embodiment, the substrate layer further comprises a side surface, the side surface connects the periphery of the first surface and the second surface, and the metal coating layer further comprises a third metal coating layer disposed on the side surface.

[0011] In one embodiment, the first metal coating is provided with a notch to expose the first surface, and cooperates with the first surface to form a groove with an opening, and the bottom wall of the groove is provided with a through hole, and the through hole sequentially passes through the first surface, the second surface and the second metal coating.

[0012] In one embodiment, the size of the opening is 0.85 to 0.95 of the length of the first surface along a direction perpendicular to the axial direction of the through hole;

[0013] And / or, the size of the through hole is 1um to 10um;

[0014] And / or, the through holes include a plurality of through holes, and the distance between two adjacent through holes is 2.5um to 10um;

[0015] And / or, the density of the through holes is 30% to 50%;

[0016] And / or, the thickness of the first metal coating is the same as the thickness of the second metal coating.

[0017] In one embodiment, the substrate layer has a first surface and a second surface that are disposed opposite to each other, and the metal coating is disposed on the second surface.

[0018] In one embodiment, the thickness of the substrate layer is 10um to 20um;

[0019] And / or, the thickness of the metal coating is 2um to 5um;

[0020] And / or, the substrate layer is polyimide, and the graphene is embedded or doped in the polyimide;

[0021] And / or, the graphene is evenly distributed in the substrate layer;

[0022] And / or, the metal coating is made of metal copper or metal nickel.

[0023] The present invention also provides a method for preparing the above-mentioned mask, the method comprising:

[0024] preparing a substrate layer containing graphene;

[0025] Depositing a coating of metal copper or metal nickel on at least a portion of the surface of the substrate layer by physical vapor deposition to form a metal coating;

[0026] Laser technology is used to form a notch on the metal coating to expose the substrate layer, so that the notch cooperates with the substrate layer to form a groove with an opening, and a through hole is opened on the bottom wall of the groove to sequentially penetrate the substrate layer and the metal coating.

[0027] In one embodiment, the step of preparing the substrate layer containing graphene includes:

[0028] With N,N'-dimethylacetamide as the reaction medium, diaminodiphenyl ether and 3,3',4,4'-dibenzophenone tetracarboxylic dianhydride as reactants, 2 Under the protection of atmosphere, polyamic acid is prepared by polycondensation reaction;

[0029] The oxidized graphene and N,N'-dimethylacetamide solvent are placed in a polytetrafluoroethylene reactor to obtain a graphene suspension through a thermal reduction reaction of the solvent;

[0030] The graphene suspension was mixed with polyamic acid in N 2 Under the protection of atmosphere, a graphene-polyamic acid solution is formed through an in-situ polymerization reaction;

[0031] The graphene-polyamic acid solution is desolvated, cured, and carbonized to obtain a substrate layer containing graphene.

[0032] In one embodiment, the steps of desolvating, curing, and carbonizing the graphene-polyamic acid solution include:

[0033] The graphene-polyamic acid solution is placed in a vacuum curing furnace to remove the solvent, and then cured to obtain a graphene-polyimide composite film;

[0034] The graphene-polyimide composite film was pretreated at 400 °C in a reducing atmosphere, then heated to 600 °C and introduced with N 2 Protective gas, carbonization is completed.

[0035] In one embodiment, the temperature of desolventizing in the vacuum curing furnace is 60° C., and the time of desolventizing in the vacuum curing furnace is 4 h to 5 h;

[0036] And / or, the curing temperature in the vacuum curing furnace is 100° C., and the curing time in the vacuum curing furnace is 1 h to 2 h;

[0037] And / or, the reducing atmosphere condition is Ar:H 2 =95:5, the pretreatment time is 1h~2h, and the carbonization time is 2h.

[0038] The present invention further provides a processing device, which includes a device body and the mask plate mentioned above, wherein the mask plate is arranged on the device body.

[0039] The mask of the technical solution of the present invention adopts a substrate layer with good thermal stability and mechanical properties as the main substrate of the mask. Since it is prepared by chemical synthesis, the thickness of the mask can be thinner and have good mechanical properties by controlling the polymerization reaction time or effectively controlling its thickness to be less than 20um, thereby achieving a higher PPI; at the same time, by doping the substrate layer with graphene, the strength of the substrate layer is improved and the sagging amount during use is reduced; further, by providing a metal coating on at least part of the surface of the substrate layer, the mask can be adsorbed by the magnet plate of the evaporation machine, further reducing the sagging amount, and making it easier to weld the mask and the frame, and protecting the surface of the mask from being scratched or damaged. It can be understood that the mask is not only thin in thickness, but also has good mechanical properties, which can achieve a higher PPI, while reducing the sagging amount of the mask during use, facilitating installation, and avoiding scratches or damage. At the same time, the preparation process of the mask does not use complex semiconductor technologies such as exposure and development, which reduces the production cost of the product. Not only is the production process simple, but also has good mechanical properties, thereby achieving a higher PPI. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0041] Figure 1 is a cross-sectional schematic diagram of a mask plate in one embodiment of the present invention;

[0042] Figure 2 is the chemical molecular formula of polyimide in one embodiment of the present invention.

[0043] Description of Figure Numbers:

[0044] Label name Label name 100 Mask 21 First Metal Coating 1 Base material layer 22 Second Metal Coating 11 First surface 23 Third metal coating 12 Second surface 3 Grooves 13 Side surface 31 Opening 2 Metal coating 4 Through Hole

[0045] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0048] At the same time, the meaning of "and / or" or "and / or" appearing in the full text includes three options. Taking "A and / or B" as an example, it includes option A, or option B, or a option in which both A and B are satisfied.

[0049] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0050] FMM stands for Fine Metal Mask, and its main material is metal or metal plus resin. The main function of the mask is to provide a shielding effect for evaporation, so that the material can be deposited in a fixed position.

[0051] Organic Light Emitting Diode (OLED) display technology has been widely used in mobile phones, televisions, and automotive fields due to its many advantages such as self-luminescence, wide color gamut, and flexible display. Due to the special application scenarios of VR and AR technologies, the display screen is required to have higher resolution and smaller size. In order to achieve high resolution, the existing micro-OLED technology uses white light OLED with color filter technology to achieve color display. This technology can avoid the use of FMM in the OLED evaporation section and realize color display by photolithography patterning RGB primary color filters. However, the color filter will lose about 80% of the brightness of the sub-pixel, and the existing white light OLED device adopts a tandem structure, which increases the overall voltage and power consumption of the device, and is also accompanied by some lateral leakage and other non-brightness phenomena. In order to meet the high-brightness, low-power OLED micro-display screens required by future VR and AR, the technology of directly depositing RGB primary colors using FMM will also be one of the technical routes of micro-OLED.

[0052] In the related art, the metal mask made of invar alloy is limited by the thickness of the raw materials and the processing technology, and the opening is difficult to reach the size required by the micro display. The opening size of the fine mask (FMM) can be achieved by etching technology to be less than 10um, but in the process of making the mask, semiconductor exposure, development, and etching technology are required, the process flow is complicated, the product cost is high, and the yield is low.

[0053] Based on the above ideas and problems, the present invention proposes a mask 100. It can be understood that the mask 100 can directly deposit RGB sub-pixels, which can replace the existing white light + color filter technology to achieve color display. At the same time, the preparation process of the mask 100 does not use complex semiconductor technologies such as exposure and development, which effectively reduces the production cost of the product. Not only is the production process simple, but the thickness can be made thinner, so it has a lighter weight, which further reduces the deformation caused by its own weight when preparing a large-sized mask.

[0054] It is understandable that the invar alloy mask commonly used in OLED is limited by the thickness of the raw material invar substrate, and it is difficult to reach a thickness of 20um or less. The smaller the thickness of the mask, the higher the PPI and the smaller the shadow can be. In this application, a high molecular polymer-polyimide with good thermal stability and mechanical properties is used as the main substrate of the mask 100. Since it is prepared by chemical synthesis, it can achieve a higher PPI by controlling the polymerization reaction time or effectively controlling its thickness to be less than 20um. At the same time, graphene is added as a reinforcing agent during the synthesis of polyimide to increase the strength of polyimide and reduce its sagging during use. A thin metal coating 2 is added to the front and back sides of the polyimide as the substrate layer 1. The metal coating 2 can not only make the mask 100 adsorbed by the magnet plate of the evaporation machine, further reducing the sagging, but also make it easier to weld between the mask 100 and the frame, and can protect the surface of the mask 100 from being scratched or damaged.

[0055] Please refer to Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the mask 100 includes a substrate layer 1 and a metal coating 2 , wherein the substrate layer 1 is doped with graphene, and the metal coating 2 is disposed on at least a portion of the surface of the substrate layer 1 .

[0056] In this embodiment, the mask plate 100 has only one substrate layer 1, and the substrate layer 1 is doped with graphene, thereby effectively improving the strength of the substrate layer 1 and reducing the sagging amount of the mask plate 100 during use.

[0057] It can be understood that graphene is embedded or dispersed in the substrate layer 1. Optionally, the substrate layer 1 is polyimide, and the graphene is embedded or doped in the polyimide. The substrate layer 1 uses a high molecular polymer-polyimide with good thermal stability and mechanical properties. Since the polyimide is prepared by chemical synthesis, a higher PPI can be achieved by controlling the polymerization reaction time or effectively controlling its thickness to be less than 20um.

[0058] In this embodiment, the mask plate 100 uses a high molecular polymer - polyimide as the material of the substrate layer 1. Compared with the traditional FMM material invar alloy, the substrate layer 1 is prepared by polymerization reaction so that the thickness of the mask plate 100 can be thinner and the mechanical properties are good.

[0059] It should be noted that the substrate layer 1 is made of polyimide (such as Figure 2As shown in the figure, the composite material is formed by doping with graphene, which effectively modifies the polyimide so that the substrate layer 1 is prepared by polymerization reaction and its thickness can reach less than 10um compared with the traditional FMM material invar alloy.

[0060] Optionally, graphene is evenly distributed in the substrate layer 1. It is understandable that graphene is a material with a good spatial structure. Since the arrangement of carbon atoms in graphene is the same as that of graphite monoatomic layer, the arrangement of carbon atoms in graphene is sp 2 The hybrid orbital bonds are grafted onto the polymer PI matrix to obtain a composite film with good mechanical properties. 2 The hybrid-connected carbon atoms are tightly stacked into a single-layer two-dimensional honeycomb lattice structure, which can effectively improve the strength of PI and reduce its sagging during use.

[0061] Optionally, the material of the metal coating 2 is metal copper or metal nickel. By setting, coating or spraying the metal coating 2 on at least part of the surface of the substrate layer 1, the metal coating 2 can make the mask plate 100 adsorbed by the magnet plate of the evaporation machine, further reduce the sagging amount, make it easier to weld the mask plate 100 and the frame, and protect the surface of the substrate layer 1 of the mask plate 100 from being scratched or damaged.

[0062] The mask plate 100 of the present invention uses a substrate layer 1 with good thermal stability and mechanical properties as the main substrate of the mask plate 100. Since it is prepared by chemical synthesis, the thickness of the mask plate 100 can be thinner and have good mechanical properties by controlling the polymerization reaction time or effectively controlling its thickness to be less than 20um, thereby achieving a higher PPI; at the same time, by doping the substrate layer 1 with graphene, the strength of the substrate layer 1 is improved and the sagging amount during use is reduced; further, by providing a metal coating 2 on at least part of the surface of the substrate layer 1, the mask plate 100 can be adsorbed by the magnet plate of the evaporation machine, further reducing the sagging amount, and making it easier to weld the mask plate 100 and the frame, and protecting the surface of the mask plate 100 from being scratched or damaged. It can be understood that the mask plate 100 is not only thin in thickness, but also has good mechanical properties, can achieve a higher PPI, and at the same time reduces the sagging amount of the mask plate 100 during use, is convenient for installation, and avoids being scratched or damaged. At the same time, the preparation process of the mask 100 does not use complex semiconductor technologies such as exposure and development, which reduces the production cost of the product. Not only is the production process simple, but it also has good mechanical properties, thereby achieving a higher PPI. The mask 100 can be used to directly deposit RGB sub-pixels, replacing the existing white light + color filter technology to achieve color display.

[0063] In one embodiment, the substrate layer 1 has a first surface 11 and a second surface 12 disposed opposite to each other, and the metal coating 2 includes a first metal coating 21 and a second metal coating 22 . The first metal coating 21 is disposed on the first surface 11 , and the second metal coating 22 is disposed on the second surface 12 .

[0064] In this embodiment, if Figure 1 As shown, the substrate layer 1 has a certain thickness, so that the substrate layer 1 has a first surface 11 and a second surface 12 that are arranged opposite to each other. Optionally, the thickness of the substrate layer 1 is 10um to 20um. It can be understood that the distance between the first surface 11 and the second surface 12 is the thickness c of the substrate layer 1. Optionally, the thickness c of the substrate layer 1 is 10um, 11um, 12um, 13um, 14um, 15um, 16um, 17um, 18um, 19um, 20um, etc., which is not limited here.

[0065] It can be understood that by providing the metal coating 2 on the first surface 11 and the second surface 12 of the substrate layer 1, the first surface 11 and the second surface 12 of the substrate layer 1 are effectively protected from being scratched or damaged, and the metal coating 2 is also conveniently used to make the mask plate 100 adsorbed by the magnet plate of the evaporation machine, further reducing the sagging amount, and making it easier to weld the mask plate 100 to the frame. Optionally, the metal coating 2 includes a first metal coating 21 and a second metal coating 22, the first metal coating 21 is provided on the first surface 11, and the second metal coating 22 is provided on the second surface 12.

[0066] In one embodiment, the substrate layer 1 further comprises a side surface 13 , the side surface 13 connects the periphery of the first surface 11 and the second surface 12 , and the metal coating layer 2 further comprises a third metal coating layer 23 disposed on the side surface 13 .

[0067] In this embodiment, if Figure 1 As shown, by providing a metal coating 2 on the side surface 13 of the substrate layer 1, the protection of the substrate layer 1 is further improved to avoid scratches or damage during use, and the mask plate 100 is adsorbed by the magnet plate of the evaporation machine to further reduce the sagging amount and make it easier to weld the mask plate 100 to the frame.

[0068] It can be understood that the two ends of the side surface 13 of the substrate layer 1 are respectively connected to the periphery of the first surface 11 and the periphery of the second surface 12, so that the side surface 13 is located on the peripheral side wall of the substrate layer 1 and between the first surface 11 and the second surface 12. Optionally, the metal coating 2 further includes a third metal coating 23, and the third metal coating 23 is provided on the side surface 13.

[0069] In one embodiment, the first metal coating 21 is provided with a notch to expose the first surface 11, and cooperates with the first surface 11 to form a groove 3 with an opening 31, and the bottom wall of the groove 3 is provided with a through hole 4, which passes through the first surface 11, the second surface 12 and the second metal coating 22 in sequence.

[0070] In this embodiment, if Figure 1 As shown, the mask plate 100 forms a groove 3 with an opening 31, and a through hole 4 is opened on the bottom wall of the groove 3. It can be understood that the side of the mask plate 100 facing away from the opening 31 of the groove 3 is the front side (that is, the side of the second metal coating 22 is the front side), and the side of the mask plate 100 with the opening 31 is the reverse side (that is, the side of the first metal coating 21 is the reverse side). By forming a notch on the first metal coating 21 of the mask plate 100, and making the notch expose the first surface 11 of the substrate layer 1, the notch is used to cooperate with the first surface 11 of the substrate layer 1 to form a groove 3 with an opening 31, so that the groove 3 is used to accommodate and limit the product to form a vapor deposition area, and the reverse side of the mask plate 100 located at the periphery of the opening 31 and the part of the substrate layer 1 that is not exposed is a non-evaporation area, that is, the edge of the FMM, that is, the part of the first metal coating 21 surrounding the opening 31 is a non-evaporation area.

[0071] It can be understood that the depth of the groove 3 is the thickness of the first metal coating 21, and the thickness of the bottom of the groove 3 is the sum of the thickness of the substrate layer 1 and the second metal coating 22. In this embodiment, the through hole 4 of the bottom wall of the groove 3 passes through the first surface 11, the second surface 12 and the second metal coating 22 in sequence.

[0072] Optionally, the thickness of the second metal coating 22 is 2um to 5um. It can be understood that the thickness d of the second metal coating 22 is the thickness of the second metal coating 22 along a direction perpendicular to the second surface 12. Optionally, the thickness d of the second metal coating 22 is 2um, 3um, 4um, 5um, etc., which is not limited here.

[0073] In this embodiment, the thickness of the first metal coating 21 may be the same as or different from the thickness of the second metal coating 22. Optionally, the thickness of the first metal coating 21 is the same as the thickness of the second metal coating 22. Of course, in other embodiments, the thickness of the first metal coating 21 is different from the thickness of the second metal coating 22, and the thickness of the first metal coating 21 may be selected from 2um to 10um. It is understandable that the thickness of the first metal coating 21 is the thickness of the first metal coating 21 in a direction perpendicular to the first surface 11. Optionally, the thickness of the first metal coating 21 is 2um, 3um, 4um, 5um, 6um, 7um, 8um, 9um, 10um, etc., which is not limited here. It should be noted that the depth of the groove 3 is the thickness of the first metal coating 21, and the depth of the groove 3 may be selected from 2um to 10um, which is not limited here.

[0074] In this embodiment, the through hole 4 on the mask plate 100 is set through the bottom wall of the groove 3. Optionally, the number of through holes 4 includes multiple, and the multiple through holes 4 are arranged at intervals. The number and size of the through holes 4 on the mask plate 100 are designed according to the requirements of the product. Optionally, the size a of the through hole 4 is 1um to 10um. The size a of the through hole 4 is related to the pixel of the product after processing. By limiting the size a of the through hole 4 to the range of 1um to 10um, the pixel of the product is effectively improved.

[0075] It can be understood that the through hole 4 can be a polygonal hole or a special-shaped hole such as a circular hole, an elliptical hole, a square hole or a triangular hole, etc., which is not limited here. In this embodiment, a circular hole is taken as an example, and the size a of the through hole 4 is the diameter of the through hole 4. The size a of the through hole 4 can be selected as 1um, 2um, 3um, 4um, 5um, 6um, 7um, 8um, 9um, 10um, etc., which is not limited here.

[0076] In one embodiment, the through holes 4 on the mask 100 include a plurality of through holes 4, and the plurality of through holes 4 are arranged at intervals, and the spacing b between two adjacent through holes 4 is 2.5um to 10um. The spacing b between the through holes 4 is related to the pixels of the product after processing. By limiting the spacing b between the through holes 4 to the range of 2.5um to 10um, the pixels of the product are effectively improved. Optionally, the spacing b between two adjacent through holes 4 is 2.5um, 3um, 4um, 5um, 6um, 7um, 8um, 9um, 10um, etc., which is not limited here.

[0077] In this embodiment, the density of the through holes 4 can be selected to be 30% to 50%. The density of the through holes 4 is the density of the through holes 4 at the bottom of the groove 3. Optionally, the density of the through holes 4 is 30%, 35%, 40%, 45%, or 50%, which is not limited here. By controlling the density of the through holes 4 within the range of 30% to 50%, the evaporation effect of the product can be ensured without affecting the structural strength of the mask 100.

[0078] In one embodiment, the width of the non-evaporation region on the reverse side of the mask plate 100 can be selected to be 5 mm to 10 mm. It can be understood that the width of the side of the groove 3 is the width of the non-evaporation region on the reverse side of the mask plate 100. Optionally, the width of the side of the groove 3 is 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc., which is not limited here.

[0079] It can be understood that the size of the opening 31 is 0.85 to 0.95 of the length of the first surface 11 along the direction perpendicular to the axial direction of the through hole 4, that is, the ratio of the size of the opening 31 to the length of the first surface 11 is 0.85 to 0.95. The size of the opening 31 is the length of the opening 31 on the reverse side of the mask plate 100, that is, the width of the vapor deposition area on the reverse side of the mask plate 100, and the length of the first surface 11 of the substrate layer 1 is the length of the reverse side of the mask plate 100, that is, the sum of the width of the non-evaporation area on the reverse side of the mask plate 100 and the width of the vapor deposition area.

[0080] It should be noted that the size of the opening 31 is the length of the first surface 11 of the substrate layer 1 minus 2*the width of the side of the groove 3 (that is, the distance from the opening 31 of the first metal coating 21 to the outer surface of the third metal coating 23). By controlling the size of the opening 31 within the range of 0.85 to 0.95 of the length of the substrate layer 1, the evaporation and accommodation of the product can be effectively achieved. Optionally, the ratio of the size of the opening 31 to the length of the first surface 11 of the substrate layer 1 is 0.85, 0.9, 0.95, etc., which is not limited here.

[0081] In one embodiment, if Figure 1 As shown, the inner wall of the groove 3 includes a bottom wall and a side wall connected to each other. It can be understood that the side wall (i.e., the inner wall of the notch of the first metal coating 21) is set at an angle with the bottom wall (i.e., the first surface 11). Optionally, the angle formed by the side wall and the bottom wall is 90° to 140°. By setting the opening 31 of the groove 3 as a flared structure, it is convenient to place or accommodate the product in the groove 3. The side wall provides guidance for the placement or accommodation of the product, which can be determined according to the process and the product, and is not limited here. Optionally, the angle formed by the side wall and the bottom wall is 90°, 100°, 110°, 120°, 130°, 135°, 140°, etc., which is not limited here.

[0082] In another embodiment, the substrate layer 1 has a first surface 11 and a second surface 12 that are disposed opposite to each other, and the metal coating 2 is disposed on the second surface 12 .

[0083] It can be understood that the metal coating 2 is only disposed on the second surface 12 of the substrate layer 1, that is, the second surface 12 of the substrate layer 1 is covered with the second metal coating 22, and the first surface 11 of the substrate layer 1 is not provided with the metal coating 2. Of course, in other embodiments, the substrate layer 1 further has a side surface 13, the side surface 13 connects the periphery of the first surface 11 and the second surface 12, and the metal coating 2 further includes a third metal coating 23 disposed on the side surface 13.

[0084] It should be noted that the third metal coating 23 can protrude from the first surface 11 of the substrate layer 1, so that the third metal coating 23 of the metal coating 2 and the first surface 11 of the substrate layer 1 form a groove 3 with an opening 31, and a through hole 4 is opened on the bottom wall of the groove 3, so that the through hole 4 passes through the first surface 11, the second surface 12 and the second metal coating 22 in sequence, which is not limited here.

[0085] The present invention also proposes a method for preparing the above-mentioned mask plate 100. The specific structure of the mask plate 100 refers to the aforementioned embodiment. Since the preparation method of the mask plate 100 adopts all the technical solutions of all the aforementioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the aforementioned embodiments, which will not be described one by one here.

[0086] In this embodiment, the preparation method comprises:

[0087] Preparing a substrate layer 1 containing graphene;

[0088] Depositing a metal copper or metal nickel coating on at least a portion of the surface of the substrate layer 1 by physical vapor deposition to form a metal coating 2;

[0089] Laser technology is used to form a notch on the metal coating 2 to expose the substrate layer 1, so that the notch and the substrate layer 1 cooperate to form a groove 3 with an opening 31, and a through hole 4 is opened on the bottom wall of the groove 3 to penetrate the substrate layer 1 and the metal coating 2 in sequence.

[0090] In this embodiment, the substrate layer 1 containing graphene can be graphene embedded in the substrate layer 1, or graphene is dispersed in the substrate layer 1, so that the graphene and the substrate layer 1 are an integrally formed structure. Optionally, the substrate layer 1 is polyimide. The substrate layer 1 adopts a high molecular polymer-polyimide with good thermal stability and mechanical properties. Since the polyimide is prepared by chemical synthesis, a higher PPI can be achieved by controlling the polymerization reaction time or effectively controlling its thickness to be less than 20um. Compared with the traditional FMM material invar alloy, the substrate layer 1 prepared by polymerization reaction can make the thickness of the mask plate 100 thinner and have good mechanical properties.

[0091] It is understandable that the graphene is optionally evenly distributed in the substrate layer 1.2 The hybrid-connected carbon atoms are tightly stacked into a single-layer two-dimensional honeycomb lattice structure, which can effectively improve the strength of PI and reduce its sagging during use.

[0092] In this embodiment, a metal material is deposited on at least a portion of the surface of the substrate layer 1 by physical vapor deposition to form a metal coating 2. Optionally, the material of the metal coating 2 is metal copper or metal nickel. It can be understood that the metal coating 2 can make the mask plate 100 adsorbed by the magnet plate of the evaporation machine, further reduce the amount of sagging, make it easier to weld the mask plate 100 and the frame, and protect the surface of the substrate layer 1 of the mask plate 100 from being scratched or damaged.

[0093] It should be noted that the substrate layer 1 has a first surface 11 and a second surface 12 that are disposed opposite to each other, and a side surface 13 located at the periphery of the substrate layer 1. The metal coating 2 can be deposited on the first surface 11 and the second surface 12 of the substrate layer 1 by physical vapor deposition; or, the metal coating 2 can be deposited on the first surface 11, the second surface 12 and the side surface 13 of the substrate layer 1 by physical vapor deposition, which is not limited here.

[0094] In this embodiment, if Figure 1 As shown, the first surface 11, the second surface 12 and the side surface 13 of the substrate layer 1 are all deposited with metal coatings 2, which are respectively the first metal coating 21, the second metal coating 22 and the third metal coating 23. Optionally, the first metal coating 21, the second metal coating 22 and the third metal coating 23 of the metal coating 2 are an integrated structure coated on the first surface 11, the second surface 12 and the side surface 13 of the substrate layer 1, which is not limited here.

[0095] It can be understood that through laser technology, laser thinning technology is first used to thin the metal coating 2 to form a notch to expose the substrate layer 1, so that the notch and the substrate layer 1 cooperate to form a groove 3 structure with an opening 31, and then laser opening technology is continued to be used to form a through hole 4 from one side of the bottom wall of the groove 3 or the other side surface of the substrate layer 1, so that the through hole 4 passes through the substrate layer 1 and the metal coating 2, so that the through hole 4 is connected to the groove 3, thereby forming the mask template 100 structure.

[0096] In this embodiment, laser thinning technology is used to thin the first metal coating 21 of the metal coating 2 to form a notch to expose the first surface 11 of the substrate layer 1, so that the notch cooperates with the first surface 11 to form a groove 3 structure with an opening 31, and laser hole opening technology is used to continue to open a through hole 4 on the bottom wall of the groove 3, so that the through hole 4 sequentially penetrates the first surface 11, the second surface 12 and the second metal coating 22; or, laser hole opening technology is used to open a hole from one side of the second metal coating 22 to form a through hole 4 that sequentially penetrates the second metal coating 22, the second surface 12 and the first surface 11, so that the through hole 4 connects to the groove 3, so as to form the mask plate 100 structure. Optionally, the area of ​​the notch opened in the first metal coating 21 of the metal coating 2 by laser hole opening technology is smaller than the area of ​​the first metal coating 21.

[0097] In one embodiment, the steps of preparing the graphene-containing substrate layer 1 include:

[0098] With N,N'-dimethylacetamide as the reaction medium, diaminodiphenyl ether and 3,3',4,4'-dibenzophenone tetracarboxylic dianhydride as reactants, 2 Under the protection of atmosphere, polyamic acid is prepared by polycondensation reaction;

[0099] The oxidized graphene and N,N'-dimethylacetamide solvent are placed in a polytetrafluoroethylene reactor to obtain a graphene suspension through a thermal reduction reaction of the solvent;

[0100] The graphene suspension was mixed with polyamic acid in N 2 Under the protection of atmosphere, a graphene-polyamic acid solution is formed through an in-situ polymerization reaction;

[0101] The graphene-polyamic acid solution is subjected to desolvation, curing treatment, and carbonization treatment to obtain a graphene-containing substrate layer 1 .

[0102] In this embodiment, polyamic acid is prepared by adding diaminodiphenyl ether (ODA) and 3,3',4,4'-dibenzophenone tetracarboxylic acid dianhydride (BDTA) into a reaction medium of N,N'-dimethylacetamide (DMAC) through a polycondensation reaction. It is understandable that in order to ensure the smooth progress of the reaction, the entire reaction process is carried out under N 2 Carried out under the protection of atmosphere.

[0103] It is understood that in the process of preparing the graphene suspension, the graphene oxide and the DMAC solvent are placed in a polytetrafluoroethylene reactor, and the graphene DMAC phase suspension is obtained by a thermal reduction reaction of the solvent. 2 Under the protection of the atmosphere, a graphene-polyamic acid solution is formed through an in-situ polymerization reaction.

[0104] In this embodiment, the graphene-polyamic acid solution is desolvated and solidified to obtain a graphene-polyimide composite film, and then the graphene-polyimide composite film is carbonized to obtain a substrate layer 1 containing graphene.

[0105] In one embodiment, the steps of desolvating, curing, and carbonizing the graphene-polyamic acid solution include:

[0106] The graphene-polyamic acid solution is placed in a vacuum curing furnace to remove the solvent, and then cured to obtain a graphene-polyimide composite film;

[0107] The graphene-polyimide composite film was pretreated at 400 °C in a reducing atmosphere, then heated to 600 °C and introduced with N 2 Protective gas, carbonization is completed.

[0108] In this embodiment, during the desolvation and curing process of the graphene-polyamic acid solution, the graphene-polyamic acid solution is placed in a vacuum curing furnace, the desolvation temperature in the vacuum curing furnace is controlled to be 60° C., and then the desolvation time in the vacuum curing furnace is controlled to be 4 h to 5 h, thereby removing the solvent. Then the curing temperature in the vacuum curing furnace is controlled to be 100° C., and the curing time in the vacuum curing furnace is set to 1 h to 2 h, and curing is performed to finally obtain a graphene-polyimide composite film.

[0109] It can be understood that during the carbonization process of the graphene-polyimide composite film, the graphene-polyimide composite film is first placed at 400°C to be pretreated under a reducing atmosphere, and the reducing atmosphere is controlled to be Ar:H 2 =95:5, pretreatment time is 1h~2h, further remove solvent, small molecules and side chains, eliminate internal stress. Then control the temperature to 600℃ and introduce N 2 Protective gas is used and the carbonization time is controlled to be 2h to complete the carbonization.

[0110] The present invention provides a mask plate 100 for directly depositing OLED materials for a micro display screen with high resolution and small pixel size, and provides a preparation process route of the mask plate 100. PI is used instead of invar as a substrate to reduce the limitation of the thickness of the material itself, and FMM with higher ppi and smaller pixel size can be prepared; at the same time, graphene is used to enhance the strength of the PI film to reduce its deformation during laser opening, net stretching and use; and a metal coating is added to the surface of the PI to increase its magnetic adsorption function, so as to facilitate adsorption with the magnetic plate of the vapor deposition machine, reduce the sagging of the mask plate 100 during use, and protect the PI.

[0111] The present invention further provides a processing device, which includes a device body and the above-mentioned mask plate 100, and the mask plate 100 is arranged on the device body. The specific structure of the mask plate 100 refers to the above-mentioned embodiment. Since the processing device adopts all the technical solutions of all the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0112] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A mask, It is characterized in that The mask comprises: a substrate layer, the substrate layer being doped with graphene; and A metal coating layer is disposed on at least a portion of the surface of the substrate layer.

2. The mask according to claim 1, It is characterized in that The substrate layer comprises a first surface and a second surface which are arranged opposite to each other. The metal coating comprises a first metal coating and a second metal coating. The first metal coating is arranged on the first surface, and the second metal coating is arranged on the second surface.

3. The mask according to claim 2, It is characterized in that The substrate layer further comprises a side surface, the side surface connects the periphery of the first surface and the second surface, and the metal coating layer further comprises a third metal coating layer disposed on the side surface.

4. The mask according to claim 2, It is characterized in that The first metal coating is provided with a notch to expose the first surface, and cooperates with the first surface to form a groove with an opening. The bottom wall of the groove is provided with a through hole, and the through hole sequentially passes through the first surface, the second surface and the second metal coating.

5. The mask according to claim 4, It is characterized in that The size of the opening is 0.85 to 0.95 of the length of the first surface along a direction perpendicular to the axial direction of the through hole; And / or, the size of the through hole is 1um to 10um; And / or, the through holes include a plurality of through holes, and the distance between two adjacent through holes is 2.5um to 10um; And / or, the density of the through holes is 30% to 50%; And / or, the thickness of the first metal coating is the same as the thickness of the second metal coating.

6. The mask according to claim 1, It is characterized in that The substrate layer has a first surface and a second surface that are disposed opposite to each other, and the metal coating is disposed on the second surface.

7. The mask according to any one of claims 1 to 6, It is characterized in that The thickness of the substrate layer is 10um to 20um; And / or, the thickness of the metal coating is 2um to 5um; And / or, the substrate layer is polyimide, and the graphene is embedded or doped in the polyimide; And / or, the graphene is evenly distributed in the substrate layer; And / or, the metal coating is made of metal copper or metal nickel.

8. A method for preparing a mask according to any one of claims 1 to 7, It is characterized in that The preparation method comprises: preparing a substrate layer containing graphene; Depositing a coating of metal copper or metal nickel on at least a portion of the surface of the substrate layer by physical vapor deposition to form a metal coating; Laser technology is used to form a notch on the metal coating to expose the substrate layer, so that the notch cooperates with the substrate layer to form a groove with an opening, and a through hole is opened on the bottom wall of the groove to sequentially penetrate the substrate layer and the metal coating.

9. The preparation method according to claim 8, It is characterized in that The step of preparing a substrate layer containing graphene comprises: With N,N'-dimethylacetamide as the reaction medium, diaminodiphenyl ether and 3,3',4,4'-dibenzophenone tetracarboxylic dianhydride as reactants, 2 Under the protection of atmosphere, polyamic acid is prepared by polycondensation reaction; The oxidized graphene and N,N'-dimethylacetamide solvent are placed in a polytetrafluoroethylene reactor to obtain a graphene suspension through a thermal reduction reaction of the solvent; The graphene suspension was mixed with polyamic acid in N 2 Under the protection of atmosphere, a graphene-polyamic acid solution is formed through an in-situ polymerization reaction; The graphene-polyamic acid solution is desolvated, cured, and carbonized to obtain a substrate layer containing graphene.

10. The preparation method according to claim 9, It is characterized in that The steps of desolvating, curing and carbonizing the graphene-polyamic acid solution include: The graphene-polyamic acid solution is placed in a vacuum curing furnace to remove the solvent, and then cured to obtain a graphene-polyimide composite film; The graphene-polyimide composite film was pretreated at 400 °C in a reducing atmosphere, then heated to 600 °C and introduced with N 2 Protective gas, carbonization is completed.

11. The preparation method according to claim 10, It is characterized in that The temperature of desolventizing in the vacuum curing furnace is 60° C., and the time of desolventizing in the vacuum curing furnace is 4 to 5 hours; And / or, the curing temperature in the vacuum curing furnace is 100° C., and the curing time in the vacuum curing furnace is 1 h to 2 h; And / or, the reducing atmosphere condition is Ar:H 2 =95:5, the pretreatment time is 1h~2h, and the carbonization time is 2h.

12. A processing device, It is characterized in that The processing equipment comprises an equipment body and a mask plate according to any one of claims 1 to 7, wherein the mask plate is arranged on the equipment body.

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