Mask plate, mask plate manufacturing method and evaporation device

Abstract

The application provides a mask plate, a mask plate preparation method and an evaporation device. A plurality of substrates are connected to form the mask plate, and the sizes of pixel openings of the substrates at different positions are different. The pixel openings at different regions of the mask plate are set to be different, and the pixel openings at the edges of the mask plate can evaporate more organic materials than when the pixel openings are set to be homogeneous, so that the evaporation shadow effect in the evaporation process is weakened, the evaporation shadow effect at the edges of the to-be-evaporated substrate is reduced, the evaporation effect of the sub-pixels is ensured, the display uniformity of the OLED display panel is ensured, the display quality of the OLED panel is improved, the preparation of the high-PPI OLED display panel is facilitated, and the new display field such as VR and AR can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a mask plate, a mask plate preparation method and an evaporation device. BACKGROUND

[0002] In the related art, when an OLED (Organic Light Emitting Diode) display panel is prepared, an evaporation film formation technology is used to pass through a high-precision metal mask plate, so that an organic material forms an organic electroluminescent structure at a sub-pixel position. However, the evaporation using the mask plate has an evaporation shadow effect. In particular, under the same Taper Angle (inclination angle) and / or Step Height (step height) conditions, the sub-pixel at the edge position of the to-be-evaporated substrate is prone to have the evaporation shadow effect problem, which affects the evaporation effect of the sub-pixel, thereby affecting the display uniformity of the OLED display panel and reducing the display quality of the OLED panel. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a mask plate, a mask plate preparation method and an evaporation device.

[0004] To achieve the above purpose, the present application provides a mask plate, comprising:

[0005] a plurality of substrates connected to each other;

[0006] The substrate is provided with a pixel opening, and the size of the pixel opening close to the edge of the mask plate is greater than the size of the pixel opening away from the edge of the mask plate.

[0007] Optionally, the substrate includes a first surface facing the evaporation source, and the angle of the included angle between the side surface of the pixel opening close to the edge of the mask plate and the first surface is greater than the angle of the included angle between the side surface away from the edge of the mask plate and the first surface.

[0008] Optionally, the substrate includes a second surface facing the to-be-evaporated substrate, and the side surface of the pixel opening includes a vertical segment close to the second surface, and the vertical segment is perpendicular to the second surface.

[0009] Optionally, the substrate includes a second surface facing the to-be-evaporated substrate, and the side surface of the pixel opening includes an inclined segment close to the second surface.

[0010] Optionally, the angle of the included angle between the side surface of the pixel opening of the substrate close to the center of the mask plate and the first surface is greater than the angle of the included angle between the side surface of the pixel opening of the substrate away from the center of the mask plate and the first surface.

[0011] Optionally, the height of the vertical segment of the substrate close to the center of the mask plate is greater than the height of the vertical segment of the substrate away from the center of the mask plate.

[0012] Optionally, the size of the substrate close to the center of the mask plate is greater than the size of the substrate away from the center of the mask plate.

[0013] The application further provides a mask plate preparation method, comprising:

[0014] Preparation of a plurality of substrates with pixel openings;

[0015] Connect the plurality of substrates to obtain a mask plate; wherein the size of the pixel opening close to the edge of the mask plate is greater than the size of the pixel opening away from the edge of the mask plate.

[0016] Optionally, the preparation of a plurality of substrates comprises:

[0017] Obtain an etching substrate; wherein the material of the etching substrate is an etching anisotropic material;

[0018] According to the target etching crystal face, the etching substrate is processed to obtain a to-be-etched substrate with a target etching crystal face;

[0019] Etch the to-be-etched substrate to obtain an etched substrate; wherein the etched recessed area of the etched substrate comprises a plurality of side faces, and the included angle between two side faces of the plurality of side faces comprises at least two kinds;

[0020] Cut the etched substrate to obtain a substrate; wherein the substrate comprises a first surface facing the evaporation source, the substrate is provided with a pixel opening, and the included angle between the side face of the pixel opening and the first surface of the substrate is related to the direction of cutting.

[0021] Optionally, according to the target etching crystal face, the etching substrate is processed, comprising:

[0022] Determine the initial crystal face of the etching substrate;

[0023] According to the initial crystal face and the target etching crystal face, determine the processing parameters;

[0024] According to the processing parameters, the etching substrate is processed.

[0025] The application further provides an evaporation device, comprising an evaporation source and the above-mentioned mask plate, and the mask plate is located on one side of the evaporation direction of the evaporation source.

[0026] As can be seen from the above, the mask, mask preparation method, and evaporation apparatus provided in this application form a mask by connecting multiple substrates, and the pixel openings of the substrates at different positions are of different sizes, thus differentiating the pixel openings in different areas of the mask. This allows the pixel openings located at the edge of the mask to evaporate more organic material than when the pixel openings are homogeneous, thereby reducing the evaporation shadow effect during the evaporation process, reducing the evaporation shadow effect at the edge of the substrate to be evaporated, ensuring the evaporation effect of the subpixels, thereby ensuring the display uniformity of the OLED display panel, and improving the display quality of the OLED panel. This is beneficial for the preparation of high PPI (Pixels Per Inch) OLED display panels, which can meet the needs of new display fields such as VR (Virtual Reality) and AR (Augmented Reality). Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the mask plate in Embodiment 1 of this application.

[0029] Figure 2 This is a schematic diagram of the mask plate in Embodiment 2 of this application.

[0030] Figure 3 This is a schematic diagram of the mask plate in Embodiment 3 of this application.

[0031] Figure 4 This is a schematic diagram of the mask plate in Embodiment 4 of this application.

[0032] Figure 5 This is a top view of the mask plate used for line source evaporation according to an embodiment of this application.

[0033] Figure 6 This is a top view of the mask plate used for point source evaporation according to an embodiment of this application.

[0034] Figure 7 This is a schematic diagram of the face-centered cubic 8-atom structure of single-crystal silicon.

[0035] Figure 8 This is an isometric structural diagram of the single-crystal silicon substrate to be etched and the mask before etching.

[0036] Figure 9A top view of a single crystal silicon substrate to be etched and a mask before etching.

[0037] Figure 10 A perspective view of a single crystal silicon substrate to be etched at the beginning of etching.

[0038] Figure 11 A top view of a single crystal silicon substrate to be etched at the beginning of etching.

[0039] Figure 12 A perspective view of a single crystal silicon substrate to be etched at the middle of etching.

[0040] Figure 13 A top view of a single crystal silicon substrate to be etched at the middle of etching.

[0041] Figure 14 A perspective view of a single crystal silicon substrate after etching.

[0042] Figure 15 A top view of a single crystal silicon substrate after etching.

[0043] Figure 16 A cutting direction for directional cutting of the etched recessed area of the single crystal silicon.

[0044] Figure 17 A cross-sectional view of the etched recessed area of the single crystal silicon after directional cutting.

[0045] The reference signs in the drawings include: substrate 1, pixel opening 2, vertical section 3, inclined section 4. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below in combination with specific embodiments and with reference to the drawings.

[0047] It should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0048] It should be noted that, unless otherwise defined, technical terms or scientific terms used in the embodiments of the present application shall have the common meaning understood by one of ordinary skill in the art to which the present application pertains. The terms such as "comprise" or "contain" or the like are intended to mean that elements or objects before the word encompass the elements or objects listed after the word, and equivalents thereof, and do not exclude other elements or objects. The terms such as "connect" or "connected" or the like are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0049] OLED display technology, with its light, self-luminous, wide viewing angle, fast response speed, low brightness, low power consumption and other advantages, is recognized as the third generation of display technology, and has become the main development direction in the field of display technology. At present, in the field of flat panel display such as mobile phone, PDA, digital camera, OLED display device has begun to replace the traditional liquid crystal display (LCD).

[0050] The structure of the OLED display device mainly includes a substrate and a plurality of sub-pixels arranged in a matrix on the substrate. In the related art, when preparing an OLED display panel, a high-precision metal mask plate is used to form an organic electroluminescent structure on the sub-pixel position of the array substrate by using evaporation film forming technology. Therefore, the size of the pixel opening of the high-precision metal mask plate directly determines the size of the sub-pixel. However, due to the thickness of the existing steel raw material, metal etching and the error caused by the mesh belt, it is difficult to improve the size of the pixel opening. However, there is an evaporation shadow effect in the evaporation using the mask plate. In particular, under the same Taper Angle or Step Height conditions, because the evaporation source is located in the middle area of the mask plate, and the edge of the mask plate is sagged due to gravity, the gap between the mask plate and the substrate to be evaporated is enlarged, so that the sub-pixel at the edge position of the substrate to be evaporated has less evaporated organic material in the evaporation process, which is prone to evaporation shadow effect problem, affecting the evaporation effect of the sub-pixel, thereby affecting the display uniformity of the OLED display panel and reducing the display quality of the OLED panel.

[0051] In view of the shortcomings of the evaporation shadow effect of the mask plate in the related art, the embodiments of the present application provide a mask plate, a mask plate preparation method and an evaporation device.

[0052] The mask plate, the mask plate preparation method and the evaporation device provided by the application are connected by a plurality of substrates to form a mask plate, and the sizes of the pixel openings of the substrates at different positions are different, the pixel openings at different regions of the mask plate are set to be different, the pixel openings at the edges of the mask plate can evaporate more organic material than when the pixel openings are set to be homogeneous, thereby weakening the evaporation shadow effect in the evaporation process, reducing the evaporation shadow effect at the edges of the substrate to be evaporated, ensuring the evaporation effect of the sub-pixel, thereby ensuring the display uniformity of the OLED display panel and improving the display quality of the OLED panel, which is conducive to the preparation of the high-PPI OLED display panel and can meet the needs of new display fields such as VR and AR.

[0053] Figures 1 to 4 The structures of the mask plates of the first embodiment to the fourth embodiment of the application are shown respectively.

[0054] Reference Figures 1 to 4 The application provides a mask plate, which comprises:

[0055] A plurality of substrates 1 are connected to each other.

[0056] The substrate 1 is provided with a pixel opening 2, and the size of the pixel opening 2 close to the edge of the mask plate is greater than the size of the pixel opening 2 away from the edge of the mask plate.

[0057] In the embodiment, the structure of the mask plate is different from that of the mask plate in the related art. The mask plate in the related art is an integrated mask plate, which is obtained by overall etching of a substrate or other processing methods. Therefore, the sizes of all the pixel openings 2 of the mask plate are the same. The mask plate in the embodiment is a combined mask plate, which is obtained by connecting a plurality of substrates 1. Therefore, the mask plate can include a plurality of substrates 1 with pixel openings 2 of different sizes, so that the sizes of the pixel openings 2 at different positions of the mask plate can be different. When the substrates 1 are connected, the edges of the substrates 1 can be bonded by an organic material, for example, the bonding organic material can be polyimide. The selection of the bonding organic material is not limited in the embodiment of the application. When the material of the substrate 1 is silicon, the edges of the substrate 1 can be heated to form SiO, and the substrates 1 are connected by in-plane bonding.

[0058] Evaporation deposition refers to a process method that a film material (or film material) is evaporated and gasified by using a certain heating evaporation method under vacuum condition, and particles fly to the surface of a substrate to condense into a film. Evaporation deposition is an early and widely used gas phase deposition technology, which has the advantages of simple film forming method, high film purity and compactness, unique film structure and performance, etc. During evaporation deposition, the evaporation source is located below, the substrate to be evaporated is located above the evaporation source, and the mask plate is located between the evaporation source and the substrate to be evaporated. Because the evaporation source is located at the center of the mask plate during the evaporation deposition process, the pixel opening 2 located at the center of the mask plate can be better evaporated, and the quality of the sub-pixel obtained is better. Under the condition that the Taper Angle and / or Step Height are the same, the sizes of all pixel openings 2 are the same, but the pixel opening 2 located at the edge of the mask plate is less evaporated due to the larger gap between the mask plate and the substrate to be evaporated and the different evaporation angles, so that the sub-pixel located at the edge of the substrate to be evaporated is prone to have the evaporation shadow effect problem, and the display uniformity of the display panel is affected.

[0059] Therefore, in order to reduce the evaporation shadow effect of the edge of the substrate to be evaporated and improve the display uniformity of the display panel, the material evaporated by the pixel opening 2 located at the edge of the mask plate during evaporation is increased.

[0060] Reference Figure 1 In Embodiment One of the present application, the substrate 1 includes a first surface facing the evaporation source, and the angle between the side of the pixel opening 2 close to the edge of the mask plate and the first surface is greater than the angle between the side away from the edge of the mask plate and the first surface.

[0061] In this embodiment, the angle between the side of the pixel opening 2 and the first surface is the Taper Angle, i.e. the angle α in the figure. By making the angle of the α angle close to the edge of the mask plate in one pixel opening 2 greater than the angle of the α angle away from the edge of the mask plate, the evaporation angle of the pixel opening 2 located at the edge of the mask plate can be similar to the evaporation angle of the pixel opening 2 located at the center of the mask plate, the evaporation shadow effect caused by different evaporation angles is reduced, the sizes of the sub-pixels at different positions are similar, and the display uniformity of the display panel is improved.

[0062] As an optional embodiment, the angle between the side of the pixel opening 2 of the substrate 1 close to the center of the mask plate and the first surface is greater than the angle between the side of the pixel opening 2 of the substrate 1 away from the center of the mask plate and the first surface.

[0063] In the embodiment, the alpha angle of the pixel opening 2 in the center of the mask plate is larger, the alpha angle of the pixel opening 2 in the edge of the mask plate is smaller, and the angle of the alpha angle is gradient distributed from the center to the edge, so that the size of the pixel opening 2 in the edge of the mask plate is larger than the size of the pixel opening 2 in the center of the mask plate, thereby increasing the material of the pixel opening 2 in the edge during evaporation, and further reducing the evaporation shadow effect of the edge of the to-be-evaporated substrate, and ensuring the evaporation effect of the sub-pixel.

[0064] Reference Figure 2 In the second embodiment of the present application, the substrate 1 includes a second surface facing the to-be-evaporated substrate, and the side surface of the pixel opening 2 includes a vertical segment 3 close to the second surface, and the vertical segment 3 is perpendicular to the second surface.

[0065] The included angle between the side surface of the pixel opening 2 of the substrate 1 close to the center of the mask plate and the first surface is larger than the included angle between the side surface of the pixel opening 2 of the substrate 1 away from the center of the mask plate and the first surface.

[0066] In the embodiment, the vertical segment 3 of the side surface of the pixel opening 2 is Step Height, and the Step Height is a measure taken to prevent the width of the pixel opening 2 from being too large due to wet etching. When the width of the pixel opening 2 is too large, the strength of the mask plate will be greatly reduced, and the mask plate is extremely easy to be damaged, especially when the thickness of the mask plate is thin, the influence of the width of the pixel opening 2 is more serious. Therefore, when wet etching is performed, the entire thickness of the mask plate is not etched completely, the thickness of the wet etching is determined according to the designed width of the pixel opening 2, and after the wet etching, dry etching or physical processing is performed on the opposite side of the etched surface to penetrate the mask plate and form a complete pixel opening 2. At this time, the side surface formed by the dry etching or physical processing is the Step Height.

[0067] In this way, the alpha angle of the pixel opening 2 in the center of the mask plate is larger, the alpha angle of the pixel opening 2 in the edge of the mask plate is smaller, and the angle of the alpha angle is gradient distributed from the center to the edge, so that the size of the pixel opening 2 in the edge of the mask plate is larger than the size of the pixel opening 2 in the center of the mask plate, thereby increasing the material of the pixel opening 2 in the edge during evaporation, and further reducing the evaporation shadow effect of the edge of the to-be-evaporated substrate, and ensuring the evaporation effect of the sub-pixel.

[0068] Reference Figure 3 In the third embodiment of the present application, the side surface of the pixel opening 2 includes an inclined segment 4 close to the second surface.

[0069] The included angle between the side surface of the pixel opening 2 of the substrate 1 close to the center of the mask plate and the first surface is larger than the included angle between the side surface of the pixel opening 2 of the substrate 1 away from the center of the mask plate and the first surface.

[0070] In the embodiment, the angle between the inclined section 4 of the side of the pixel opening 2 and the second surface is the angle β in the figure. The inclined section 4 is a measure taken to prevent the wet etching from causing the width of the pixel opening 2 to be too large. When the width of the pixel opening 2 is too large, the strength of the mask plate will be greatly reduced, and the mask plate will be extremely prone to damage, especially when the thickness of the mask plate is thin, the impact of the width of the pixel opening 2 being too large is more serious. Therefore, when performing the first wet etching, the mask plate is not etched completely, the thickness of the first wet etching is determined according to the width of the pixel opening 2 designed, and after the first wet etching, the second wet etching is performed on the opposite side of the etching surface to penetrate the mask plate and form a complete pixel opening 2, at this time, the side formed by the second wet etching is the inclined section 4.

[0071] In this way, the angle α of the pixel opening 2 in the center of the mask plate is large, and the angle α of the pixel opening 2 at the edge of the mask plate is small. By making the angle α of the gradient distribution from the center to the edge, the size of the pixel opening 2 at the edge of the mask plate can be greater than the size of the pixel opening 2 in the center of the mask plate, thereby increasing the material of the pixel opening 2 at the edge during evaporation, and further reducing the evaporation shadow effect of the edge of the substrate to be evaporated, and ensuring the evaporation effect of the sub-pixel.

[0072] Reference Figure 4 In the fourth embodiment of the present application, the side of the pixel opening 2 includes a vertical section 3 close to the second surface, and the vertical section 3 is perpendicular to the second surface.

[0073] The height of the vertical section 3 of the substrate 1 close to the center of the mask plate is greater than the height of the vertical section 3 of the substrate 1 away from the center of the mask plate.

[0074] In the embodiment, the height of the Step Height decreases from the center of the mask plate to the edge of the mask plate. When the height of the Step Height of all pixel openings 2 is the same, the Step Height at the edge of the mask plate will block more evaporation of the evaporation source than the Step Height of the pixel opening 2 in the center of the mask plate. Therefore, by reducing the height of the Step Height of the pixel opening 2 at the edge of the mask plate, the evaporation of the pixel opening 2 at the edge of the mask plate can be increased, and further the evaporation shadow effect of the edge of the substrate to be evaporated can be reduced, and the evaporation effect of the sub-pixel can be ensured.

[0075] Figure 5 A top view structure of a mask plate for line source evaporation according to an embodiment of the present application is shown. Figure 6 A top view structure of a mask plate for point source evaporation according to an embodiment of the present application is shown.

[0076] Reference Figure 5 and Figure 6As an optional embodiment, the size of the substrate 1 close to the center of the mask plate is larger than the size of the substrate 1 far from the center of the mask plate.

[0077] In the embodiment, the substrate 1 at the center of the mask plate is larger, the substrate 1 at the edge of the mask plate is smaller, and the size of the substrate 1 is distributed in a gradient from the center to the edge. The size of the substrate 1 in the gradient distribution can make the interval between the pixel openings 2 at the edge of the mask plate smaller than the interval between the pixel openings 2 at the center of the mask plate, so that the angle of the evaporation angle of the pixel openings 2 at the edge of the mask plate is similar to the angle of the evaporation angle of the pixel openings 2 at the center of the mask plate, and the evaporation shadow effect caused by different evaporation angles is reduced.

[0078] Reference Figure 5 When the evaporation source is a line source crucible, the line source crucible moves in the long direction of the mask plate during evaporation. At this time, the size of the substrate 1 decreases in a gradient from the center to the edge, that is, the width of the substrate 1 becomes narrower.

[0079] Reference Figure 6 When the evaporation source is a point source crucible, the point source crucible does not move during evaporation, and the mask plate rotates. At this time, the size of the substrate 1 decreases in a gradient from the center to the edge, that is, the ring width of the substrate 1 becomes smaller.

[0080] Based on the same inventive concept, the application further provides a mask plate preparation method, comprising:

[0081] Preparation of a plurality of substrates 1 provided with pixel openings 2.

[0082] Connecting a plurality of substrates 1 to obtain a mask plate. Wherein the size of the pixel openings 2 close to the edge of the mask plate is larger than the size of the pixel openings 2 far from the edge of the mask plate.

[0083] In the present embodiment, in order to prepare the mask plate of the above-mentioned embodiment, it is necessary to prepare a pixel opening 2 with different sizes, i.e. to prepare a substrate 1 with different Taper Angles or Step Heights. The prior art mask plate is a fine metal mask (FMM) with a material such as Invar, which is an isotropic metal in wet etching and is difficult to etch into different Taper Angles or Step Heights by etching. Therefore, it is necessary to use a material with etching anisotropy as the substrate material, for example, single crystal silicon or a silicon compound (such as silicon oxide or silicon nitride), which has the advantages of directional etching, small thermal expansion, no adhesion and plasticity, and because the density of single crystal silicon or a silicon compound is relatively low, the self-weight of the same size has less effect on the substrate 1 than the fine metal mask, so that the thickness of the substrate 1 formed by single crystal silicon or a silicon compound can be much smaller than that of the metal substrate (the thickness of single crystal silicon can be thinned to 5 μm), further reducing the evaporation shadow effect of the edge of the to-be-evaporated substrate, ensuring the evaporation effect of the sub-pixel, thereby ensuring the display uniformity of the OLED display panel and improving the display quality of the OLED panel, which is beneficial to the preparation of high-PPI OLED display panels.

[0084] As an optional embodiment, a plurality of substrates 1 are prepared, including:

[0085] An etching substrate is obtained. The material of the etching substrate is an etching anisotropic material.

[0086] The etching anisotropic material has different atomic numbers on different crystal faces, so that the wet etching rates of different crystal faces are different. For example, for single crystal silicon with a face-centered cubic 8-atom structure as shown in Figure 7 the wet etching rates of different crystal faces are (100):(110):(111)=100:16:1. Therefore, the shape of the etched recessed area of the single crystal silicon substrate after wet etching can be accurately calculated, and the desired Taper Angle can be accurately obtained.

[0087] The etching substrate is processed according to the target etching crystal face to obtain a to-be-etched substrate with a surface of the target etching crystal face.

[0088] In the embodiment, in order to perform directional etching on the etching substrate, the etching substrate needs to be processed to expose the target etching crystal surface designed in advance, and the target etching crystal surface of the etching substrate is etched to obtain the designed etching recessed region. For example, for a single crystal silicon etching substrate, the target etching crystal surface can be a (110) crystal surface. When the (110) crystal surface is etched, the etching rate of the crystal surface of the {111} crystal surface family is extremely low, so that the etching recessed region finally formed is surrounded by the crystal surface of the {111} crystal surface family.

[0089] The etching substrate is etched to obtain an etched substrate. The etching recessed region of the etched substrate includes a plurality of side surfaces, and the included angle between two side surfaces of the plurality of side surfaces includes at least two types.

[0090] In the embodiment, a mask is arranged on the target etching crystal surface, and then etching is performed to obtain an etched substrate. The mask can be exposed organic material, such as polyimide. For single crystal silicon, the mask can also be a SiO mask formed by thermal oxidation on the target etching crystal surface. The shape of the mask can be rectangular or circular. Different mask shapes can obtain different etching recessed regions. The material and shape of the mask are not limited in the embodiment. For single crystal silicon, the etching solution can be an alkali solution, such as potassium hydroxide or tetramethylammonium hydroxide. The selection of the etching solution is not limited in the embodiment.

[0091] Because of the etching anisotropy of the material, after etching, the etching recessed region will form a plurality of side surfaces with different included angles. For example, Figures 8 to 15 The process of etching a single crystal silicon etching substrate is shown. Wherein, Figure 8 and Figure 9 The axonometric structure and the top-down structure of the single crystal silicon etching substrate and the mask before etching are shown. Before etching, a mask with a rectangular opening is arranged on the target etching crystal surface. Figure 10 and Figure 11 The axonometric structure and the top-down structure of the single crystal silicon etching substrate at the initial stage of etching are shown. At the initial stage of etching, the single crystal silicon etching substrate forms Figure 10 and Figure 11 seven surfaces in and, ①-⑥ are {111} crystal surface family, respectively, (-111)(-11-1)(11-1)(1-1-1)(1-11)(111), ⑦ is a (110) surface parallel to the upper surface, wherein (-111) / / (1-1-1), (-11-1) / / (1-11), the included angle between (-111) and (1-11) is 109.47°, the four surfaces of (-111)(-11-1)(1-1-1)(1-11) are all perpendicular to (110), and the included angle between (11-1) and (111) is 70.53°. Figure 12 andFigure 13 The axonometric structure and the plan view structure of the single crystal silicon substrate to be etched at the middle of the etching process are shown. It can be seen that, as the etching proceeds, the ② plane intersects with the ⑥ plane, the ③ plane intersects with the ⑤ plane, and the ⑦ plane gradually becomes smaller. Figure 14 and Figure 15 The axonometric structure and the plan view structure of the single crystal silicon substrate after etching are shown respectively. It can be seen that, after the etching is completed, the ③ plane intersects with the ⑥ plane, the ⑦ plane disappears, and the etching recessed region of the six planes in the ⑧ plane is formed. Figure 14 and Figure 15 The axonometric structure and the plan view structure of the single crystal silicon substrate after etching are shown respectively. It can be seen that, after the etching is completed, the ③ plane intersects with the ⑥ plane, the ⑦ plane disappears, and the etching recessed region of the six planes in the ⑧ plane is formed.

[0092] The etched substrate is cut to obtain a substrate 1. The substrate 1 includes a first surface facing the evaporation source, and the substrate 1 is provided with a pixel opening 2. The angle between the side surface of the pixel opening 2 and the first surface of the substrate 1 is related to the cutting direction.

[0093] In this embodiment, different Taper Angles of the substrate 1 are obtained by cutting the etching recessed region at different angles and positions. For example, Figure 16 The cutting direction of the directional cutting of the etching recessed region of the single crystal silicon is shown. Figure 17 The cross section after the directional cutting of the etching recessed region of the single crystal silicon is shown. It can be seen from the figure that the directional cutting along the A-A' cross section and the B-B' cross section can obtain different Taper Angles. It can be understood that other angle cutting of the etching recessed region can obtain Taper Angles of other angles, and the cross section and the Taper Angle obtained by other angle cutting are not shown in the figure. In addition, the etching recessed region is cut at the same angle and different positions, and cross sections with different etching depths can also be obtained. The substrate 1 of these cross sections is subjected to secondary etching, and the substrate 1 with different Step Heights can be obtained.

[0094] In this way, by cutting the etching recessed region at different angles and positions, the substrate 1 with different Taper Angles and Step Heights can be obtained. The substrates 1 are connected, and the mask plate of the above-mentioned embodiment can be obtained.

[0095] As an optional embodiment, a single crystal silicon wafer is processed according to a target etching crystal plane, comprising:

[0096] The initial crystal plane of the etching substrate is determined.

[0097] In this embodiment, the initial crystal plane of the etching substrate is characterized by EBSD (Electron Back Scattered Diffraction).

[0098] EBSD is a technique that uses a diffraction electron beam to identify the crystallographic orientation of a sample. Mounted in a scanning electron microscope (SEM), the electron beam is accelerated to an angle of about 70 degrees, and is incident on the sample to produce backscattered electrons that are diffracted by the surface crystal structure, carrying information about the orientation of the grains on the surface of the sample into a detector, thereby determining the directionality of each grain. Knowing the orientation of each grain, it can be used to determine the grain boundary, phase identification, grain orientation, texture and strain analysis method.

[0099] According to the initial crystal surface and the target etching crystal surface, the processing parameters are determined.

[0100] In this embodiment, the processing angle and position of the target etching crystal surface from the initial crystal surface are obtained through crystallographic calculation.

[0101] According to the processing parameters, the etching substrate is processed.

[0102] In this embodiment, the cutting or masking is performed according to the obtained processing angle and position, and the etching substrate with the surface being the target etching crystal surface is obtained.

[0103] Based on the same inventive concept, the application also provides a kind of evaporation device corresponding to the mask plate of any of the above embodiments, comprising evaporation source and the mask plate described above, mask plate is located in the evaporation direction side of evaporation source.

[0104] Those skilled in the art should understand that the above discussion of any of the embodiments is only exemplary and is not intended to suggest that the scope (including claims) of the present application is limited to these examples; under the idea of the present application, the above embodiments or technical features in different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the embodiments of the present application as described above. In order to be brief, they are not provided in detail.

[0105] Although the present application has been described in conjunction with specific embodiments thereof, many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description.

[0106] The embodiments of the present application are intended to cover all such alternatives, modifications and variations which fall within the broad scope of the appended claims. Accordingly, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present application should be included in the protection scope of the present application.

Claims

1. A mask, characterized in that, The application relates to a mask plate, comprising: a plurality of substrates connected to each other; the substrates are provided with a plurality of pixel openings of different sizes, the size of the pixel openings close to the edge of the mask plate is larger than the size of the pixel openings far from the edge of the mask plate; wherein the substrate comprises a first surface facing the evaporation source, the angle of the included angle between the side surface of the pixel opening close to the edge of the mask plate and the first surface is larger than the angle of the included angle between the side surface far from the edge of the mask plate and the first surface; the included angle between the side surface of the pixel opening of the substrate close to the center of the mask plate and the first surface is larger than the included angle between the side surface of the pixel opening of the substrate far from the center of the mask plate and the first surface; the size of the substrate close to the center of the mask plate is larger than the size of the substrate far from the center of the mask plate.

2. The mask defined in claim 1, wherein The substrate comprises a second surface facing the substrate to be evaporated, and the side surface of the pixel opening comprises a vertical segment close to the second surface, and the vertical segment is perpendicular to the second surface.

3. The mask defined in claim 1, wherein The substrate comprises a second surface facing the substrate to be evaporated, and the side surface of the pixel opening comprises an inclined segment close to the second surface.

4. The mask defined in claim 2, wherein The height of the vertical segment of the substrate close to the center of the mask plate is larger than the height of the vertical segment of the substrate far from the center of the mask plate.

5. A method of manufacturing a mask according to any one of claims 1 to 4, characterized in that, The application relates to a mask plate, comprising: a plurality of substrates provided with pixel openings; the plurality of substrates are connected to obtain the mask plate; wherein the size of the pixel openings close to the edge of the mask plate is larger than the size of the pixel openings far from the edge of the mask plate.

6. The mask preparation method of claim 5, wherein, The preparation of the plurality of substrates comprises: an etching substrate is obtained; wherein the material of the etching substrate is an etching anisotropic material; the etching substrate is processed according to a target etching crystal face to obtain a to-be-etched substrate with a surface of the target etching crystal face; the to-be-etched substrate is etched to obtain an etched substrate; wherein the etched recessed area of the etched substrate comprises a plurality of side surfaces, and the included angle between two side surfaces of the plurality of side surfaces comprises at least two kinds; the etched substrate is cut to obtain the substrate; wherein the substrate comprises a first surface facing the evaporation source, the substrate is provided with pixel openings, and the angle of the included angle between the side surface of the pixel opening and the first surface of the substrate is related to the cutting direction.

7. The mask preparation method of claim 6, wherein, The processing of the etching substrate according to the target etching crystal face comprises: an initial crystal face of the etching substrate is determined; processing parameters are determined according to the initial crystal face and the target etching crystal face; the etching substrate is processed according to the processing parameters.

8. An evaporation device, characterized by The application relates to an evaporation source and a mask plate according to any one of claims 1-4, and the mask plate is located on one side of the evaporation direction of the evaporation source.

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