Method for manufacturing mask plate and mask plate

Abstract

The present invention provides a mask plate manufacturing method and a mask plate manufactured by the method, the mask plate manufacturing method comprising: stretching a stainless steel sheet as a mask; laser cutting the stainless steel sheet to form a desired mask through-hole pattern; welding the cut stainless steel sheet to a mask plate frame, removing excess portions to obtain a semi-finished mask plate; taking another stainless steel sheet to make a protective sheet, protecting the semi-finished mask plate and polishing the through-hole edges, and cleaning to obtain the final mask plate. Due to the mask plate manufacturing method provided in the present application, defects such as burrs on the through-hole edges are removed by polishing, thereby improving the manufacturing yield of the mask plate. Since the mask plate provided in the present application is manufactured by the above method, defects such as burrs on the through-hole edges of the mask plate are avoided, thereby improving the quality of the mask plate and the quality of OLED evaporation.

Description

Technical Field

[0001] The present invention relates to the technical field of evaporation, and more particularly to a method for manufacturing a mask plate and the mask plate thereof. Background Art

[0002] Organic electroluminescent devices (OLEDs) are considered the next generation of flat-panel displays due to their low cost, high brightness, high contrast, fast response, low power consumption, wide viewing angle, thin and lightweight design, and flexible display capabilities. OLEDs consist of an anode, an organic light-emitting layer, and a cathode stacked sequentially on a glass substrate. The materials used in the organic light-emitting layer are generally categorized as either macromolecular organic materials or small-molecule organic materials. For small-molecule organic materials, vacuum evaporation is typically used to form the various organic functional layers on the anode, which then forms the device's cathode.

[0003] In the process of producing OLED thin films by evaporation, different masks need to be replaced to deposit different functional layers. The OLED coating mask is composed of a thin magnetic stainless steel sheet and a magnetic stainless steel frame. In the prior art, various rectangular, circular or other types of through holes are pre-opened on the thin steel sheet. During OLED production, the mask is adsorbed together with the OLED substrate by magnets. In a vacuum environment, organic materials or metal vapors will be deposited in the through-hole areas not blocked by the stainless steel mask to form the specific pattern required by the designer. The parts covered by the mask are protected by no material deposition. In a vacuum, the OLED substrate and the mask are suspended above the evaporated material by magnetic adsorption. Since the pattern on the substrate is very precise, the material constituting the mask is required to have good magnetic conductivity and very smooth and regular opening lines.

[0004] One of the mainstream methods for manufacturing existing mask plates is laser cutting. The steel sheet is first stretched and tightened, and then the evaporation holes are cut out with a laser. The evaporation holes are then welded to the mask frame. This production method does not require the use of chemical liquids and does not produce waste liquid to pollute the environment. The required pattern can be realized by simply inputting the design pattern into the laser cutting machine and the movement path of the laser machine. The mesh does not require a special mesh stretching machine, and the process is simple. At present, a serious problem with the laser cutting method for manufacturing mask plates is that during laser cutting, a certain wavelength of laser is used to burn the stainless steel sheet and apply a partial downward force. The cutting edge will cause burrs and other irregular edges. This defect will rub and scratch the circuit or organic material layer on the OLED substrate during the OLED evaporation alignment process, resulting in large-area poor display of the product. Summary of the Invention

[0005] In view of this, the present invention provides a mask plate and a method for manufacturing the same, which improves the existing method of manufacturing mask plates by laser cutting and adds a process of polishing the edges of the through holes, thereby solving the problem that the current laser cutting method of manufacturing mask plates will have defects such as burrs, which may cause scratches on the OLED substrate.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for manufacturing a mask plate, comprising:

[0008] Take a wire mesh, stretch it horizontally and tighten it, take an aluminum frame, apply glue on one side of the frame, and then stick it on the stretched wire mesh. After the glue dries and adheres firmly, cut the wire mesh along the outer edge of the aluminum frame to make a mesh frame;

[0009] Take the cut stainless steel sheet, apply glue on the edges of one side of the stainless steel sheet, and stick it horizontally on the mesh frame in the center to make the stainless steel sheet and the mesh stick to each other;

[0010] After the glue dries, cut off the wire mesh under the stainless steel sheet. The wire mesh between the stainless steel sheet and the aluminum frame will tighten the stainless steel sheet.

[0011] Place the stretched steel sheet into a laser cutting machine and use laser to cut out the required through-hole pattern (i.e., evaporation holes) according to the designed pattern to produce a stainless steel mask;

[0012] Provide a mask frame, put the cut stainless steel mask with a mesh frame on the mask frame, and weld the stainless steel mask with a through-hole pattern to the mask frame using a laser welding machine;

[0013] Using a laser cutting machine to cut and remove the stainless steel sheet and the mesh frame along the outer edge of the mask frame to obtain a semi-finished mask plate;

[0014] Taking another stainless steel sheet, using a laser cutting machine to cut a large through-hole pattern, the large through-hole pattern corresponding to the through-hole pattern in the semi-finished mask plate, but the opening of each large through-hole is larger than the opening of the through-hole in the semi-finished mask plate, to produce a stainless steel protective sheet;

[0015] Place the semi-finished mask plate on a magnetic table with the stainless steel mask facing downward and the frame facing upward. Cover the semi-finished stainless steel mask plate with a stainless steel protective sheet so that only the edges of the through-holes of the stainless steel mask are exposed. Hold the protective sheet firmly in place and use sandpaper to polish the edges of each through-hole of the stainless steel mask to remove burrs.

[0016] The polished mask plate semi-finished product is cleaned and dried to obtain the final mask plate finished product.

[0017] Preferably, the aluminum frame is a "mouth"-shaped frame.

[0018] Preferably, a cut stainless steel sheet is taken, glue is applied around the edges of one side of the stainless steel sheet, and the sheet is horizontally attached to the mesh frame in the center so that the stainless steel sheet and the wire mesh stick to each other; the size of the stainless steel sheet is 5mm-50mm smaller than the size of the aluminum frame on one side, including the end value.

[0019] Preferably, after the stainless steel through-hole pattern is cut out, a yarn cutting step is also performed, that is, a portion of the mesh yarn connecting the stainless steel sheet and the aluminum frame is cut off.

[0020] Preferably, the magnetic table is an electromagnetic table that becomes magnetic when powered, and the surface of the magnetic table is a marble surface.

[0021] Preferably, the cleaning comprises steps such as acid cleaning, alkali cleaning, deionized water cleaning and organic solvent cleaning.

[0022] Preferably, the drying temperature is 50-80°C, including endpoint values.

[0023] The present invention also provides a mask plate, comprising: a mask and a mask frame located at the periphery of the mask, wherein the mask plate is manufactured by the above mask plate manufacturing method.

[0024] Preferably, the mask frame of the mask plate has a thickness ranging from 5 mm to 30 mm, including end points.

[0025] Preferably, the thickness of the mask is 0.03 to 0.2 mm, inclusive.

[0026] Preferably, the mask plate is made of metal, metal alloy, or stainless steel.

[0027] Through the above technical solutions, it can be seen that the mask plate manufacturing method provided by the present invention adds a protective sheet to grind the edge of the through hole of the mask plate, which can remove the edge burrs caused by laser cutting without damaging the mask in other non-through hole areas. It solves the problem of scratching the OLED substrate without causing other defects, greatly improves the manufacturing quality of the mask plate, and thus greatly improves the OLED evaporation yield.

[0028] At the same time, the present invention also provides a mask plate formed by the above-mentioned manufacturing method. Since defects such as burrs on the edges of the mask through holes are effectively removed during the manufacturing process of the mask plate, the quality of the mask plate is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0030] Figure 1 A step diagram of a mask manufacturing method provided in this application;

[0031] Figure 2 This is a schematic diagram of a protective mask protected by a protective sheet in an embodiment of the present application;

[0032] Figure 3 for Figure 2 AA cross-sectional structural diagram;

[0033] Figure 4 A schematic diagram of a mask product provided in this application;

[0034] Figure 5 for Figure 4 Schematic diagram of the BB cross-sectional structure. DETAILED DESCRIPTION

[0035] As described in the background technology section, the existing mask laser cutting method may produce burrs due to the sharp edge, affecting the manufacturing yield of the mask, or the defects may flow to the OLED evaporation process, causing scratches on the OLED product and poor display.

[0036] Based on this, the inventors have discovered through research that a method for manufacturing a mask plate includes the following steps:

[0037] Take the stainless steel sheet used as a mask and stretch the net horizontally;

[0038] Laser cutting is used to cut the tensioned stainless steel sheet to form the required mask through-hole pattern;

[0039] Welding the cut stainless steel sheet to the mask frame, removing excess stainless steel sheet and mesh frame to obtain a semi-finished mask plate;

[0040] Taking another stainless steel sheet and cutting it with a laser into a protective sheet that matches the through-hole pattern of the stainless steel mask;

[0041] Protect the semi-finished mask plate and polish the edges of the through holes to remove burrs;

[0042] Clean to obtain the final mask.

[0043] As can be seen from the above technical solution, the mask plate manufacturing method provided by the present invention, by adding a polishing step, removes burrs and other imperfections from the edges of the mask plate's through-holes, ultimately forming the mask plate. This added polishing step improves the mask plate's manufacturing yield and reduces the probability of the mask plate scratching the OLED substrate, thereby improving the mask plate's manufacturing yield and performance, reducing the risk of substrate scratches during the OLED vapor deposition process, and improving the yield of the entire OLED vapor deposition process.

[0044] The above is the core idea of ​​this application. The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0045] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0046] Next, the present invention is described in detail with reference to schematic diagrams. For ease of illustration, when describing embodiments of the present invention, cross-sectional views illustrating device structures may be partially enlarged and not to scale. Furthermore, these schematic diagrams are merely illustrative and should not limit the scope of protection of the present invention. Furthermore, in actual production, three-dimensional dimensions, including length, width, and depth, should be included.

[0047] The following is a detailed description through examples.

[0048] The embodiment of the present invention discloses a method for manufacturing a mask plate, which is used in OLED vacuum evaporation technology. Figures 1 to 3 As shown, the following steps are included:

[0049] S101: Take a wire mesh, stretch it horizontally and tighten it, take an aluminum frame, apply glue on one side of the frame, and then stick it on the stretched wire mesh. After the glue dries and adheres firmly, cut the wire mesh along the outer edge of the aluminum frame to make a mesh frame;

[0050] It should be noted that the aluminum frame is a "mouth"-shaped frame, and the side of the aluminum frame that contacts the wire mesh must be flat. The conventional practice is to place it on a marble platform and use a feeler gauge to check its surface flatness. If it is uneven, it must be flattened or polished.

[0051] S102: Take the cut stainless steel sheet, apply glue around the edges of one side of the steel sheet, and stick it horizontally on the center of the mesh frame to ensure that the stainless steel sheet and the mesh stick to each other;

[0052] It should be noted that the stainless steel sheet can be a SUS series stainless steel sheet, an INVAR stainless steel sheet or other metal sheets, alloy metal sheets, etc.

[0053] It should be noted that the size of the stainless steel sheet is 5mm-50mm smaller than the size of the aluminum frame on one side, including the end value. The glue used in this step is AB glue, which is applied after stirring and allowed to dry naturally for a while.

[0054] S103: After the glue dries, cut off the wire mesh under the stainless steel sheet. The wire mesh between the stainless steel sheet and the aluminum frame will tighten the stainless steel sheet.

[0055] It should be noted that the screen should be cut along the edge of the glue, and the stainless steel sheet should not be scratched during the cutting process; and the area of ​​this area must be larger than the outer dimensions of the mask frame to avoid interference during subsequent welding.

[0056] S104: placing the stretched steel sheet into a laser cutting machine, and using a laser to cut out the desired through-hole 111 pattern (i.e., vapor deposition holes) according to the designed pattern, to produce a stainless steel mask 11;

[0057] It should be noted that when cutting, laser cutting can be performed with the aluminum frame facing down and the wire mesh facing up, or with the aluminum frame facing up and the wire mesh facing down.

[0058] It should be noted that the mask through holes 111 can be rectangular, circular, or triangular in shape, and can be arranged in a regular or irregular pattern such as a matrix or a herringbone pattern. The shape and arrangement of the through holes 111 can be determined based on the specific requirements of the coating, and are not limited in this embodiment.

[0059] It should be noted that after the stainless steel through-hole 111 pattern is cut out, since the stainless steel sheet mask 11 in the middle is no longer a complete stainless steel sheet, part of the stainless steel mask 11 is separated by the through-hole 111, and the stainless steel mask 11 between some of the through-holes 111 is still intact. This causes uneven force on the entire stainless steel sheet mask 11, and the entire surface is uneven, especially when the through-holes 111 are larger or the through-holes 111 are more irregularly arranged. At this time, the uniformity of the tensile force on the stainless steel sheet mask 11 can be adjusted by cutting off part of the mesh connecting the stainless steel sheet mask 11 and the aluminum frame. Generally, the mesh connecting the stainless steel sheet mask 11 and the aluminum frame corresponding to the through-holes 111 is cut off. You can start by cutting off a few pieces of mesh until the entire stainless steel sheet mask 11 with through-holes 111 is flat.

[0060] S105: providing a mask frame 12, putting the cut stainless mask 11 with a mesh frame on the mask frame 12, and welding the stainless mask 11 with a through-hole 111 pattern to the mask frame 12 using a laser welding machine;

[0061] It should be noted that the material of the mask frame 12 is metal, metal alloy, or stainless steel; the shape of the mask frame 12 can be a hollow rectangle, circle, polygon, or the like.

[0062] It should be noted that laser welding is performed by uniformly welding the stainless steel mask 11 to the mask frame along the outer edge of the mask frame 12. During welding, if the aluminum frame was cut downward and the screen was upward in the aforementioned laser cutting step S104, then in this step, the aluminum frame is placed on the mask frame 12 with the screen facing upward and welding is performed. If the aluminum frame was cut upward and the screen was downward in the aforementioned laser cutting step S104, then in this step, the aluminum frame is placed on the mask frame 12 with the screen facing downward and welding is performed. This ensures that the laser cutting surface is on the side away from the mask frame 12.

[0063] S106: Using a laser cutting machine to cut and remove the stainless steel sheet and the mesh frame along the outer edge of the mask frame 12 to obtain a semi-finished mask plate;

[0064] S107: Take another stainless steel sheet and cut a pattern of large through holes 211 using a laser cutting machine. The pattern of the large through holes 211 corresponds one-to-one with the pattern of the through holes 111 in the semi-finished mask plate. However, the opening of each large through hole 211 is larger than the opening of the through hole 111 in the semi-finished mask plate, thereby producing a stainless steel protective sheet 21.

[0065] It should be noted that the stainless steel sheet can be made of the same material as the stainless steel sheet of the stainless steel mask 11 used in step S102, or it can be made of a different material. The outer dimensions of the stainless steel protective sheet 21 must be smaller than the inner dimensions of the mask frame 12 so that it can be placed inside the mask frame 12 during subsequent protection.

[0066] S108: Place the semi-finished mask plate on a magnetic table with the stainless steel mask 11 facing downward and the mask plate frame 12 facing upward. Cover the semi-finished stainless steel mask 11 with the stainless steel protective sheet 21 so that only the edge portion 112 of the stainless steel mask through-hole 111 is exposed. Hold the protective sheet 21 in place and polish each through-hole edge 112 of the stainless steel mask with sandpaper to remove burrs.

[0067] It should be noted that the magnetic table is an electromagnetic table that becomes magnetic when powered on, and the surface of the magnetic table is made of marble. When powered on, the protective sheet 21 and the stainless steel mask 11 are magnetically attracted to each other, preventing them from moving and causing friction during polishing. After polishing, the protective sheet 21 and the stainless steel mask 11 are disconnected and no longer magnetic, allowing them to be easily separated and removed from the magnetic table.

[0068] S109: The polished semi-finished mask plate is cleaned and dried to obtain a final finished mask plate.

[0069] It should be noted that the cleaning includes steps of acid cleaning, alkali cleaning, deionized water cleaning and organic solvent cleaning. The drying temperature is 50-80°C, including the end value.

[0070] In this embodiment, since a grinding process is added during the production of the mask plate, the burrs on the edge 112 of the mask through hole can be effectively removed. At the same time, since the protective sheet 21 is added to protect the non-through hole area, scratches in other areas are effectively prevented, which can greatly improve the yield of the mask plate laser cutting manufacturing.

[0071] The present application also provides a mask plate 1 obtained by the manufacturing method in the above embodiment, such as Figure 4 , Figure 5 As shown, it comprises a mask frame 12 and a mask 11 located inside the mask frame. The mask plate 1 is made of metal, metal alloy, or stainless steel.

[0072] The mask 11 has a mask through hole 111 for the evaporation material to pass through. The thickness of the mask 11 is in the range of 0.03 mm to 0.2 mm, inclusive. To ensure that the mask plate 1 has good mechanical strength, the thickness of the mask frame 12 is preferably in the range of 5 mm to 30 mm, inclusive.

[0073] The mask plate 1 provided in this embodiment adopts the mask plate manufacturing method provided in the above embodiments, thereby effectively removing defects such as burrs on the edges of the mask through holes, thereby ensuring the quality of the mask plate 1 to a certain extent.

[0074] The various parts in this manual are described in a progressive manner, and each part focuses on the differences from other parts. The same or similar parts between the various parts can be referenced to each other.

[0075] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for manufacturing a mask plate, characterized in that: include: Take a wire mesh, stretch it horizontally and tighten it, take an aluminum frame, apply glue on one side of the frame, and then stick it on the stretched wire mesh. After the glue dries and adheres firmly, cut the wire mesh along the outer edge of the aluminum frame to make a mesh frame; Take the cut stainless steel sheet, apply glue on the edges of one side of the stainless steel sheet, and stick it horizontally on the mesh frame in the center to make the stainless steel sheet and the mesh stick to each other; After the glue dries, cut off the wire mesh under the stainless steel sheet, and use the wire mesh between the stainless steel sheet and the aluminum frame to tighten the stainless steel sheet; Place the stretched steel sheet into the laser cutting machine and use the laser to cut out the required through-hole pattern according to the designed pattern to make a stainless steel mask; Provide a mask frame, put the cut stainless steel mask with a mesh frame on the mask frame, and weld the stainless steel mask with a through-hole pattern to the mask frame using a laser welding machine; Using a laser cutting machine to cut and remove the stainless steel sheet and the mesh frame along the outer edge of the mask frame to obtain a semi-finished mask plate; Taking another stainless steel sheet, cutting a large through-hole pattern using a laser cutting machine, the large through-hole pattern corresponding one-to-one to the through-hole pattern in the semi-finished mask plate, but with the opening of each large through-hole larger than the opening of the through-hole in the semi-finished mask plate, thereby producing a stainless steel protective sheet; Place the semi-finished mask plate on a magnetic table with the stainless steel mask facing downward and the frame facing upward. Cover the semi-finished stainless steel mask plate with a stainless steel protective sheet so that only the edges of the through-holes of the stainless steel mask are exposed. Hold the protective sheet firmly in place and use sandpaper to polish the edges of each through-hole of the stainless steel mask to remove burrs. The polished mask plate semi-finished product is cleaned and dried to obtain the final mask plate finished product.

2. The method according to claim 1, characterized in that Take the cut stainless steel sheet, apply glue on the edges of one side of the steel sheet, and stick it horizontally on the center of the mesh frame so that the stainless steel sheet and the wire mesh stick to each other; the size of the stainless steel sheet is 5mm-50mm smaller than the size of the aluminum frame on one side, including the end value.

3. The method according to claim 1, characterized in that The method further comprises: after laser cutting the stainless steel through-hole pattern, cutting off a portion of the mesh connecting the stainless steel sheet and the aluminum frame.

4. The method according to claim 1, wherein The magnetic table is an electromagnetic table which becomes magnetic when powered, and the surface of the magnetic table is a marble plane.

5. The method according to claim 1, wherein The cleaning comprises the steps of acid cleaning, alkali cleaning, deionized water cleaning and organic solvent cleaning.

6. The method according to claim 1, characterized in that The drying temperature is 50-80° C., including endpoint values.

7. A mask plate, characterized in that: include: A mask and a mask frame located around the mask, wherein the mask plate is manufactured by the method according to any one of claims 1 to 6.

8. The mask according to claim 7, wherein: The mask frame of the mask plate has a thickness ranging from 5 mm to 30 mm, including end points.

9. The mask according to claim 8, characterized in that: The thickness of the mask is 0.03 to 0.2 mm, inclusive.

10. The mask according to any one of claims 7 to 9, characterized in that: The mask plate is made of metal, which includes a metal alloy.

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