Mask plate, mask plate assembly and preparation method of mask plate

Abstract

The invention discloses a mask plate, a mask plate assembly and a preparation method of the mask plate, the mask plate is used for forming an evaporation pattern on a target substrate, the mask plate comprises a mask layer provided with a plurality of first openings penetrating through the mask layer, the first openings correspond to the evaporation pattern, and the mask layer comprises a polymer film layer; the supporting layer is stacked on the mask layer and provided with at least one second opening penetrating through the supporting layer, and the first openings are exposed out of the second opening. According to the mask plate, the precision of the mask plate can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of mask plates, and in particular to a mask plate, a mask plate assembly and a method for preparing the mask plate. Background Art

[0002] At present, the main processing technology for mass production of OLED (Organic Light-Emitting Diode) devices in display panels is vacuum evaporation, in which a mask plate is required. With the development of display technology, the demand for PPI (Pixels Per Inch) of display panels is getting higher and higher, which also poses a considerable challenge to the processing of mask plates. Summary of the invention

[0003] The present application provides a mask plate, a mask plate assembly and a method for preparing the mask plate, which can improve the accuracy of the mask plate.

[0004] A first aspect of an embodiment of the present application provides a mask plate for forming a vapor deposition pattern on a target substrate, the mask plate comprising: a mask layer, having a plurality of first openings passing through the mask layer, the first openings corresponding to the vapor deposition pattern, the mask layer comprising a polymer film layer; a support layer, stacked with the mask layer, having at least one second opening passing through the support layer, wherein the second opening exposes a plurality of the first openings.

[0005] A second aspect of an embodiment of the present application provides a mask plate assembly, comprising any of the mask plates described above.

[0006] A third aspect of an embodiment of the present application provides a method for preparing a mask plate, the method comprising: preparing a mask layer, wherein the mask layer is provided with a plurality of first openings penetrating the mask layer, the first openings corresponding to a vapor deposition pattern, and the mask layer comprises a polymer film layer; stacking the mask layer and a support layer, wherein the support layer is provided with at least one second opening penetrating the support layer, and the second opening exposes a plurality of the first openings; and fixedly connecting the mask layer and the support layer.

[0007] The beneficial effect is that the present application prepares the first opening on the polymer film layer with high graphic precision, and uses the support layer to support the polymer film layer, so as to realize the processing of high-precision and high-density openings and ensure the precision of the mask plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0009] Figure 1 It is a schematic diagram of a top view structure of an embodiment of a mask plate of the present application;

[0010] Figure 2 yes Figure 1 A schematic diagram of a partial cross-sectional structure of the mask plate along the section line AA';

[0011] Figure 3 is a schematic structural diagram of an embodiment of the present invention when a mask plate is used for evaporation;

[0012] Figure 4 is a schematic diagram of a top view of another embodiment of the mask plate of the present application;

[0013] Figure 5 1 is a schematic diagram of a top view structure of a display panel;

[0014] Figure 6 is a schematic diagram of a top view of another embodiment of the mask plate of the present application;

[0015] Figure 7 is a schematic diagram of a mask plate when it is translated in one embodiment;

[0016] Figure 8 is a schematic diagram of the relative positions of the second opening and the sub-pixel during the preparation process;

[0017] Fig. 9 It is a structural schematic diagram of an implementation method of a mask plate assembly of the present application;

[0018] Fig.10 It is a schematic diagram of a process of an embodiment of a method for preparing a display panel of the present application;

[0019] Fig.11 It corresponds to Fig.10 Diagram of the preparation process. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] It should be noted that the terms "first" and "second" in this application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0022] Before introducing the solution of the present application, it should be noted that the mask plate of the present application can be used not only for the preparation of display panels, but also for the preparation of other structures, for example, for the preparation of chips. And when using the mask plate to prepare display panels, the mask plate can be used not only for evaporation of sub-pixels, but also for evaporation of other structures. In short, the present application does not limit the application scenarios of the mask plate.

[0023] See also Figures 1 to 3 In one embodiment, the mask plate 100 is used to form an evaporation pattern on a target substrate 20 , and the mask plate 100 includes a mask layer 110 and a support layer 120 .

[0024] The mask layer 110 is provided with a plurality of first openings 1101 penetrating the mask layer 110, and the first openings 1101 correspond to the evaporation pattern, and the mask layer 110 includes a polymer film layer 111. Specifically, the first openings 1101 penetrate the mask layer 110 in the thickness direction, which also includes the polymer film layer 111 in the mask layer 110. After the evaporation material passes through the first openings 1101 and reaches the target substrate 20, an evaporation pattern is formed on the target substrate 20. The first openings 1101 have the same shape and size as the evaporation pattern, and the first openings 1101 determine the shape and size of the evaporation pattern finally formed. The polymer film layer 111 generally has excellent properties such as high thermal stability and low thermal expansion coefficient, and has high graphic accuracy. Through the etching process, high-precision and high-density opening processing can be achieved on the polymer film layer 111.

[0025] The support layer 120 and the mask layer 110 are stacked and provided with at least one second opening 1201 penetrating the support layer 120, wherein the second opening 1201 exposes a plurality of first openings 1101. Specifically, the support layer 120 supports and spreads the mask layer 110, and the second opening 1201 penetrates the support layer 120 in the thickness direction, and the second opening 1201 exposes a plurality of first openings 1101, that is, the orthographic projection of the second opening 1201 on the target plane parallel to the mask plate 100 covers the orthographic projection of the plurality of first openings 1101 on the target plane. During evaporation, the evaporation material sprayed from the evaporation source 10 sequentially passes through the second opening 1201 and the first opening 1101 to reach the target substrate 20, and finally forms an evaporation pattern.

[0026] It can be seen from the above content that the present application prepares the first opening 1101 on the polymer film layer 111 with high graphic accuracy, and uses the support layer 120 to support the mask layer 110, which can achieve high-precision and high-density opening processing and ensure the processing accuracy of the mask plate 100.

[0027] In one embodiment, the evaporation pattern is a sub-pixel in the display panel. Specifically, the mask plate 100 in the present application can be used to evaporate and form a light-emitting material layer in the sub-pixel on the target substrate 20. It can be understood that the arrangement of the first openings 1101 exposed by the mask plate 100 is the same as the arrangement of the sub-pixels in the display panel. When the sub-pixels in the display panel are arranged in a matrix, the first openings 1101 in the mask plate 100 are also arranged in a matrix.

[0028] In one embodiment, the polymer film layer 111 has a thermal expansion coefficient less than or equal to 8 ppm / °C from room temperature to 300°C. For example, the polymer film layer 111 has a thermal expansion coefficient of 2 ppm / °C, 2.5 ppm / °C, 5 ppm / °C or 8 ppm / °C from room temperature to 300°C. Preferably, the polymer film layer 111 has a thermal expansion coefficient of 3 to 5 ppm / °C from room temperature to 300°C.

[0029] For example, the polymer film layer 111 has a thermal expansion coefficient of 3 ppm / °C, 3.5 ppm / °C, 4 ppm / °C, 4.5 ppm / °C or 5 ppm / °C from room temperature to 300°C. This setting can reduce deformation of the polymer film layer 111 during the evaporation process.

[0030] In one embodiment, the difference between the thermal expansion coefficient of the polymer film layer 111 and the thermal expansion coefficient of the target substrate 20 is set to be in the range of 1 to 3 ppm / °C, for example, the difference is 1 ppm / °C, 2 ppm / °C or 3 ppm / °C; that is, the thermal expansion coefficient of the polymer film layer 111 is set close to the thermal expansion coefficient of the target substrate 20, so that during the evaporation process, the expansion amplitudes of the polymer film layer 111 and the target substrate 20 are the same or close, thereby reducing the deviation of the evaporation pattern formed on the target substrate 20.

[0031] In one embodiment, the thermal expansion coefficient of the polymer film layer 111 is equal to the thermal expansion coefficient of the target substrate 20 .

[0032] In one embodiment, the material of the target substrate 20 includes glass, and the difference between the thermal expansion coefficient of the polymer film layer 111 and the thermal expansion coefficient of the glass is set to be 1-3 ppm / °C, or the thermal expansion coefficient of the polymer film layer 111 is set to be equal to the thermal expansion coefficient of the glass.

[0033] In one embodiment, the material of the polymer film layer 111 includes polyimide (PI).

[0034] In one embodiment, the thickness of the polymer film layer 111 is in the range of 2 to 20 micrometers. For example, the thickness of the polymer film layer 111 is 2 micrometers, 5 micrometers, 10 micrometers, or 20 micrometers.

[0035] Continue reading Figure 1 In one embodiment, the cross section of the first opening 1101 parallel to the mask plate 100 is rectangular, that is, the orthographic projection of the first opening 1101 on the target plane parallel to the mask plate 100 is rectangular, see Figure 4 In another embodiment, the cross section of the first opening 1101 parallel to the mask plate 100 is a rounded rectangle, that is, the orthographic projection of the first opening 1101 on the target plane parallel to the mask plate 100 is a rounded rectangle.

[0036] Continue reading Figure 2 In one embodiment, on the plane where the vertical cross section of the first opening 1101 is located, the side wall of the first opening 1101 extends along the thickness direction of the mask plate 100, that is, the cross section of the first opening 1101 perpendicular to the mask plate 100 is rectangular, and this arrangement can make the hole wall of the first opening 1101 smooth, and can prevent the deposition material from accumulating in the first opening 1101. In other embodiments, the cross section of the first opening 1101 perpendicular to the mask plate 100 can also be in other shapes such as a trapezoid, which is not limited here.

[0037] In one embodiment, the side length of the orthographic projection of the first opening 1101 on the target plane (a plane parallel to the mask plate 100) ranges from 3 to 60 microns, for example, 3 microns, 10 microns, 20 microns or 60 microns, etc. It should be noted that the side lengths of the first opening 1101 and the second opening 1201 mentioned in this application refer to the side lengths of the orthographic projections of the first opening 1101 and the second opening 1201 on the target plane. For the sake of convenience, they are directly referred to as the side lengths of the first opening 1101 and the second opening 1201 below.

[0038] Specifically, the length of any side of the first opening 1101 is in the range of 3 to 60 micrometers. It is understandable that the shape and size of the first opening 1101 need to be set according to the evaporation pattern.

[0039] Continue reading Figure 1 In one embodiment, the distance between the side wall of the second opening 1201 and the outermost side wall of the cluster formed by the plurality of first openings 1101 is in the range of 0.1 to 0.3 mm. Specifically, the second opening 1201 includes a central area B, and the first opening 1101 is exposed from the central area B of the second opening 1201, wherein the distance a between the boundary of the central area B and the side wall of the second opening 1201 is in the range of 0.1 to 0.3 mm, that is, the outer expansion range of the second opening 1201 relative to the first opening 1101 exposed from the second opening 1201 is 0.1 to 0.3 mm, which can also be understood as the distance between the outermost side of the orthographic projection of the plurality of first openings 1101 exposed in the second opening 1201 on the target plane and the edge of the orthographic projection of the second opening 1201 on the target plane is in the range of 0.1 to 0.3 mm.

[0040] Among them, the distance a is equal to 0.1 mm, 0.2 mm or 0.3 mm, etc. Setting the range of distance a to 0.1-0.3 mm can, on the one hand, prevent the side wall of the second opening 1201 from affecting the evaporation material passing through the first opening 1101, and on the other hand, ensure that the support layer 120 has sufficient support force for the mask layer 110.

[0041] The shapes of the cross section of the second opening 1201 parallel to the mask plate 100 and the cross section of the first opening 1101 parallel to the mask plate 100 may be the same or different.

[0042] Continue reading Figure 1In one embodiment, the second opening 1201 is a rectangular opening, that is, the orthographic projection of the second opening 1201 on the target plane parallel to the mask plate 100 is rectangular, that is, the cross-section of the second opening 1201 parallel to the mask plate 100 is rectangular. Of course, in other embodiments, the second opening 1201 can also be a circular opening, a triangular opening, or a rounded rectangular opening, which can be selected according to actual needs.

[0043] Continue reading Figure 2 , on the plane where the vertical cross section of the second opening 1201 is located, the side wall of the second opening 1201 extends along the thickness direction of the mask plate 100, that is, the cross section of the second opening 1201 perpendicular to the mask plate 100 is rectangular, and this arrangement can make the hole wall of the second opening 1201 smooth, and can prevent the deposition material from accumulating in the second opening 1201. In other embodiments, the cross section of the second opening 1201 perpendicular to the mask plate 100 can also be in other shapes such as a trapezoid, which is not limited here.

[0044] Continue reading Figure 2 In one embodiment, the mask layer 110 also includes a magnetic film layer 112 and a first bonding layer 113. The magnetic film layer 112 and the polymer film layer 111 are stacked and located on the side of the polymer film layer 111 close to the support layer 120. The first bonding layer 113 is arranged between the magnetic film layer 112 and the polymer film layer 111, and is used to bond the magnetic film layer 112 and the polymer film layer 111. That is, in the direction close to the support layer 120, the polymer film layer 111, the first bonding layer 113 and the magnetic film layer 112 are stacked in sequence.

[0045] Specifically, the first bonding layer 113 is used to ensure the connection strength between the polymer film layer 111 and the magnetic film layer 112 . In other embodiments, the first bonding layer 113 may not be provided.

[0046] The magnetic film layer 112 has magnetic properties and can be attracted by ferromagnetism. Figure 3 During the evaporation process, the evaporation source 10 is located below the target substrate 20, the mask plate 100 is located between the evaporation source 10 and the target substrate 20, and the magnet 30 is located above the target substrate 20. Since the magnetic film layer 112 is magnetic, the magnetic film layer 112 can be attracted by the magnet 30, and the polymer film layer 111 is connected to the magnetic film layer 112, so the polymer film layer 111 can be indirectly attracted by the magnet 30, and the attraction generated by the magnet 30 can counteract the gravity of the polymer film layer 111 itself, thereby preventing the polymer film layer 111 from sagging and deforming under the action of gravity.

[0047] In one embodiment, the material of the magnetic film layer 112 includes a ferromagnetic material. For example, the material of the magnetic film layer 112 includes at least one of nickel, iron, and Invar. It is sufficient that the magnetic film layer 112 has magnetic properties and can be attracted by the magnet 30.

[0048] In one embodiment, the thickness of the magnetic film layer 112 is in the range of 1 to 20 micrometers. For example, the thickness of the magnetic film layer 112 is 1 micrometer, 2 micrometers, 5 micrometers, 10 micrometers, or 20 micrometers.

[0049] In one embodiment, the material of the first bonding layer 113 includes an inorganic material, for example, the material of the first bonding layer 113 includes at least one of amorphous silicon, silicon oxide, and silicon nitride. The first bonding layer 113 is a single-layer structure or a stacked-layer structure, and the present application does not limit the specific structure of the first bonding layer 113.

[0050] In one embodiment, the thickness of the first adhesive layer 113 is in the range of 10 to 1000 nanometers. For example, the thickness of the first adhesive layer 113 is 10 nanometers, 100 nanometers, 500 nanometers, or 1000 nanometers.

[0051] In one embodiment, in order to reduce the deformation of the mask layer 110 during the evaporation process, the thermal expansion coefficients of the first bonding layer 113, the magnetic film layer 112, and the polymer film layer 111 are set to be equal or similar. In other embodiments, only the thermal expansion coefficients of the magnetic film layer 112 and the polymer film layer 111 may be set to be equal or similar.

[0052] In one embodiment, the material of the support layer 120 includes metal. The metal has high strength, which can ensure that the support layer 120 has a strong supporting force and prevent the polymer film layer 111 from deforming and affecting the evaporation accuracy.

[0053] In one embodiment, the support layer 120 has magnetic properties, so that during the evaporation process, the support layer 120 can be attracted by the magnet 30 to prevent the mask plate 100 from falling.

[0054] In one embodiment, the thermal expansion coefficient of the support layer 120 is equal to or close to that of the mask layer 110 , so that during the evaporation process, the support layer 120 and the mask layer 110 expand to the same or similar extent, thereby preventing the mask plate 100 from deforming.

[0055] In one embodiment, the thermal expansion coefficient of the support layer 120 is equal to or close to the thermal expansion coefficient of the target substrate 20 , so that the deviation of the evaporated material formed on the target substrate 20 can be reduced.

[0056] In one embodiment, the support layer 120 is a common metal mask (CMM). The common metal mask CMM has high strength and strong support capability, and can prevent the mask layer 110 from being deformed.

[0057] In one embodiment, the thickness of the support layer 120 is in the range of 20 to 100 micrometers. For example, the thickness of the support layer 120 is 20 micrometers, 50 micrometers, or 100 micrometers.

[0058] In one embodiment, the mask layer 110 and the support layer 120 are connected via an adhesive medium layer, that is, the adhesive medium layer is disposed between the mask layer 110 and the support layer 120 and connects the mask layer 110 and the support layer 120, wherein the material of the adhesive medium layer may include glue, or may include temporary bonding glue, resin glue, solder, metal, alloy solder, and other materials that can be heated for reflow soldering.

[0059] In other embodiments, the mask layer 110 and the support layer 120 may also be connected by a connection method without an adhesive medium, that is, the mask layer 110 and the support layer 120 are arranged in close contact with each other and are directly contacted and connected. For example, the mask layer 110 and the support layer 120 are connected by at least one connection method without an adhesive medium, such as direct mechanical pressing or laser welding.

[0060] Continue reading Figure 1 There are multiple second openings 1201, and multiple first openings 1101 are exposed in each second opening 1201. The number of first openings 1101 exposed in different second openings 1201 can be equal or different, and can be set according to actual needs.

[0061] In one embodiment, the second openings 1201 have the same shape and size to simplify processing, wherein the second openings 1201 have the same shape and size, which means that the orthographic projections of the second openings 1201 on a target plane parallel to the mask plate 100 have the same shape and size.

[0062] In one embodiment, if Figure 1 As shown, the plurality of second openings 1201 are arranged in a matrix.

[0063] It should be noted that the present application does not impose any restrictions on the shape, size, and arrangement of the second openings 1201 , and they can be specifically configured according to actual needs.

[0064] In one embodiment, a plurality of display panels can be prepared simultaneously using the mask plate 100, that is, a vapor deposition pattern can be formed on the target substrate 20 in a plurality of display panels simultaneously using the mask plate 100, that is, a plurality of first openings 1101 in the mask layer 110 correspond to the vapor deposition patterns on the plurality of display panels. The first openings 1101 corresponding to the vapor deposition patterns on the display panels means that the vapor deposition patterns in the display panels can be vapor deposited through the first openings 1101.

[0065] In another embodiment, the mask plate 100 can be used to prepare only one display panel at a time, that is, the mask plate 100 can be used to form the vapor deposition pattern in only one display panel at a time.

[0066] Continue reading Figure 1 In one embodiment, when the mask plate 100 is used to prepare multiple display panels at the same time, the first openings 1101 corresponding to the vapor deposition patterns on different display panels are exposed in different second openings 1201, so that the vapor deposition patterns in different display panels can be prepared by exposing the first openings 1101 in different second openings 1201. This setting can also make it possible to prepare a suitable number of display panels by selectively blocking part of the second openings 1201 during the preparation process. For example, assuming that 100 display panels can be prepared without blocking any second openings 1201, and when only 50 display panels are to be prepared, the second openings 1201 corresponding to 50 of the display panels can be selected to be blocked.

[0067] Continue reading Figure 1 In one embodiment, a plurality of first openings 1101 corresponding to the vapor deposition pattern on the same display panel are exposed in the same second opening 1201 , that is, a display panel can be prepared by exposing the first opening 1101 in a second opening 1201 .

[0068] In this embodiment, when the evaporation pattern includes sub-pixels in the display panel, Figure 5 , the size of the second opening 1201 is the same as the size of the effective display area AA of the display panel, that is, the width of the second opening 1201 is equal to the width of the effective display area of ​​the display panel, and the length of the second opening 1201 is equal to the length of the effective display area of ​​the display panel. Among them, the effective display area of ​​the display panel refers to the area where the display panel actually displays the picture, and is also the area where the light-emitting sub-pixels are located. Other areas of the display panel outside the effective display area will not display the picture. At this time, the first opening 1101 exposed in a second opening 1201 can be used to complete the evaporation of all sub-pixels in the effective display area of ​​a display panel.

[0069] In other embodiments, the size of the second opening 1201 may also be slightly larger than the size of the effective display area of ​​the display panel.

[0070] In this embodiment, the length range of the second opening 1201 is 5 to 400 mm (that is, the length range of the orthographic projection of the second opening 1201 on the target plane is 5 to 400 mm), for example, the length of the second opening 1201 is 5 mm, 10 mm, 100 mm, 300 mm or 400 mm.

[0071] In this embodiment, the width of the second opening 1201 ranges from 3 to 200 mm (that is, the width of the orthographic projection of the second opening 1201 on the target plane ranges from 3 to 200 mm), for example, the width of the second opening 1201 is 3 mm, 10 mm, 100 mm or 200 mm.

[0072] See also Figure 6 In another embodiment, a plurality of first openings 1101 corresponding to the same display panel vapor deposition pattern are exposed in different second openings 1201, that is, the preparation of all vapor deposition patterns on a display panel can be completed only through the first opening 1101 exposed from the plurality of second openings 1201. Figure 1 Compared with the embodiment, this embodiment can reduce the opening area of ​​the second opening 1201, reduce the area of ​​the unsupported mask layer 110, and prevent the mask layer 110 from being deformed due to a large area without support.

[0073] Continue reading Figure 6 In one embodiment, the evaporation pattern includes sub-pixels in the display panel, and the second openings 1201 extend along the first direction X. The multiple second openings 1201 corresponding to the same display panel are arranged into multiple opening rows in the second direction Y, and each opening row includes at least one second opening 1201, wherein the first direction X is the same as the extension direction of the pixel rows in the display panel, and the second direction Y is the same as the arrangement direction of the pixel rows in the display panel, that is, the second direction Y is the same as the extension direction of the pixel columns in the display panel.

[0074] Specifically, the second opening 1201 is a strip-shaped opening, and the extension direction of the second opening 1201 is the same as the extension direction of the pixel row in the display panel. At the same time, the first opening 1101 used for evaporating the sub-pixels in the same pixel row in the display panel is exposed in the second opening 1201 in the same opening row.

[0075] Each opening row includes one or more second openings 1201. In one embodiment, considering that the distance between two adjacent sub-pixels in a pixel row is small, it is difficult to prepare multiple first openings 1101 for sub-pixels in the same pixel row and expose them in different second openings 1201. Therefore, each opening row is set to include only one second opening 1201, so that during the preparation process, the first openings 1101 used to prepare sub-pixels in the same pixel row are all exposed in the same second opening 1201.

[0076] For the sake of convenience, the side extending along the first direction X in the orthographic projection of the second opening 1201 on the target plane is defined as the first side, the side extending along the second direction Y is defined as the second side, and the side whose extending direction of the effective display area of ​​the display panel is the same as the extending direction of the pixel row is defined as the third side. When the display panel is applied to terminal devices such as mobile phones, the third side of the effective display area of ​​the display panel is usually the short side of the effective display area of ​​the display panel.

[0077] In one embodiment, when the opening row includes only one second opening 1201, since it is necessary to use multiple first openings 1101 exposed in one second opening 1201 to prepare all sub-pixels in the same pixel row, the side length L1 of the first side is set equal to the side length L3 of the third side of the effective display area of ​​the display panel.

[0078] It can be understood that the side length L2 of the second side of the second opening 1201 determines the number of pixel rows that can be prepared through the second opening 1201 during the preparation process. For example, in one embodiment, the side length L2 of the second side of the second opening 1201 is set to a suitable value so that during the preparation process, sub-pixels in 10 adjacent pixel rows can be prepared through the first opening 1101 exposed in the second opening 1201.

[0079] See also Figure 6 , Figure 7 as well as Figure 8 , Figure 8The diagram shows the relative positions of the second opening 1201 and the sub-pixels in the display panel during the preparation process. In one embodiment, the two second openings 1201 adjacent to each other in the second direction Y are defined as the first target opening 1201a and the second target opening 1201b, respectively. The pixel row corresponding to the plurality of first openings 1101 exposed from the first target opening 1201a is defined as the first pixel row 1101a. The pixel row corresponding to the plurality of first openings 1101 exposed from the second target opening 1201b is defined as the second pixel row 1101b. The pixel row between the first pixel row 1101a and the second pixel row 1101b is defined as the third pixel row 1101c, wherein the number of the first pixel row 1101a, the second pixel row 1101b and the third pixel row 1101c are equal. This setting allows the evaporation of all sub-pixels on the display panel to be completed by translating the mask plate 100 once during the preparation process. For example, in the first evaporation process, the mask plate 100 can be used to evaporate the sub-pixels in the 1st to 6th rows, the sub-pixels in the 13th to 18th rows..., and in the process of translating the mask plate 100 for the second evaporation, the sub-pixels in the 7th to 12th rows, the sub-pixels in the 19th to 24th rows... can be evaporated.

[0080] In one embodiment, the plurality of first openings 1101 exposed from the second openings 1201 correspond to an integer number of sub-pixels in the display panel. This arrangement allows a sub-pixel to be complete after only one evaporation, thereby avoiding the need for multiple preparations to complete a sub-pixel.

[0081] In one embodiment, during the preparation process, multiple first openings 1101 exposed from one second opening 1201 can be used to prepare sub-pixels in an integer number of pixel rows. For example, multiple first openings 1101 exposed from the second opening 1201 can be used to evaporate sub-pixels in adjacent 5 or 10 pixel rows. This setting can ensure that the sub-pixels in each pixel row are completed during the same evaporation process, avoiding the need for multiple preparations before and after a sub-pixel is completed, thereby reducing the difficulty of preparation. For ease of understanding, this is explained in conjunction with an example:

[0082] In one embodiment, during the first evaporation process, the mask plate 100 can be used to evaporate sub-pixels in the 1st to 10th rows, sub-pixels in the 21st to 30th rows, sub-pixels in the 41st to 50th rows..., and during the second evaporation process of translating the mask plate 100, sub-pixels in the 11th to 20th rows, sub-pixels in the 31st to 40th rows, sub-pixels in the 51st to 60th rows... can be evaporated.

[0083] In one embodiment, the multiple first openings 1101 exposed from the second opening 1201 correspond to sub-pixels in an integer number of pixel units, and this setting can ensure that the sub-pixels in the same pixel unit are evaporated in the same evaporation process. For ease of understanding, an example is used for explanation: the multiple first openings 1101 exposed from the second opening 1201 can evaporate sub-pixels in 5 pixel units, that is, if a pixel unit includes 3 sub-pixels, 15 first openings 1101 are exposed in the second opening 1201.

[0084] In one embodiment, the side length L1 of the first side of the second opening 1201 ranges from 5 to 400 mm, such as 5 mm, 10 mm, 100 mm, 300 mm or 400 mm.

[0085] In one embodiment, the side length L2 of the second side of the second opening 1201 ranges from 0.5 to 5 mm, for example, 0.5 mm, 1 mm, 3 mm or 5 mm.

[0086] See also Fig. 9 The present application also includes a mask plate assembly, including at least one mask plate 100 in any one of the above embodiments.

[0087] Continue reading Fig. 9 In one embodiment, there are multiple mask plates 100, and the first openings 1101 of the multiple mask plates 100 are arranged so that when the multiple mask plates 100 are stacked, the number and arrangement of the multiple exposed first openings 1101 correspond to the number and arrangement of the multiple evaporation patterns, so that in the preparation process, multiple mask plates 100 can be used to evaporate all the evaporation patterns in succession.

[0088] This arrangement allows the first openings 1101 corresponding to the multiple evaporation patterns to be distributed in the polymer film layers 111 in the multiple mask plates 100, thereby reducing the opening area of ​​each polymer film layer 111 and the opening area of ​​the support layer 120 in each mask plate 100, thereby reducing the unsupported area of ​​the polymer film layer 111 in each mask plate 100, thereby preventing the polymer film layer 111 from being deformed due to a large area without support.

[0089] The sizes of the multiple mask plates 100 may be the same or different. The same size of the multiple mask plates 100 means that the lengths and widths of the different mask plates 100 are equal, that is, when the multiple mask plates 100 are stacked, the orthographic projections of the multiple mask plates 100 on the target plane parallel to the mask plates 100 are overlapped.

[0090] In one embodiment, in combination Fig. 9In one embodiment, the evaporation pattern includes sub-pixels in the display panel, the second opening 1201 extends along the first direction X in which the pixel rows in the display panel extend, and the plurality of second openings 1201 corresponding to the same display panel are arranged into a plurality of opening rows in the second direction Y in which the pixel columns in the display panel extend, and each opening row includes at least one second opening 1201:

[0091] exist Fig. 9 In the example, there are two mask plates 100. Assuming that one of the mask plates 100 can be used to evaporate the 1st to 10th rows of sub-pixels, the 21st to 30th rows of sub-pixels, the 41st to 50th rows of sub-pixels... in the display panel during the first evaporation, then the other mask plate 100 can be used to evaporate the 11th to 20th rows of sub-pixels, the 31st to 40th rows of sub-pixels, the 51st to 60th rows of sub-pixels... in the display panel during the second evaporation, thereby finally completing the evaporation of all the sub-pixels in the display panel.

[0092] See also Figure 1 , Figure 2 as well as Fig.10 In one embodiment of the present application, a method for preparing the mask plate 100 includes:

[0093] S110 : preparing a mask layer 110 , wherein the mask layer 110 is provided with a plurality of first openings 1101 penetrating the mask layer 110 , the first openings 1101 corresponding to the evaporation pattern, and the mask layer 110 includes a polymer film layer 111 .

[0094] S120 : stacking the mask layer 110 and the support layer 120 , wherein the support layer 120 is provided with at least one second opening 1201 penetrating the support layer 120 , and the second opening 1201 exposes a plurality of first openings 1101 .

[0095] S130: The mask layer 110 and the support layer 120 are fixedly connected.

[0096] Specifically, after the mask layer 110 and the support layer 120 are prepared, the mask layer 110 and the support layer 120 are stacked and placed, and the two are compositely connected together.

[0097] See also Fig.11 In one embodiment, the specific process of preparing the mask layer 110 in step S110 includes:

[0098] S111 : forming a mask layer 110 on the support substrate 40 .

[0099] Specifically, the support substrate 40 plays a supporting role, and its material can be glass or other materials, which is not limited here.

[0100] At the same time, the step S120 of stacking the mask layer 110 and the support layer 120 includes:

[0101] S121 : placing the support layer 120 on the side of the mask layer 110 away from the support substrate 40 so as to be stacked with the mask layer 110 .

[0102] And, after step S130, the method further includes:

[0103] S140 : removing the support substrate 40 .

[0104] The support substrate 40 may be removed by, for example, laser removal or mechanical removal.

[0105] In one embodiment, step S111 of forming a mask layer 110 on the support substrate 40 includes:

[0106] S1111 : forming a polymer thin film layer 111 on the supporting substrate 40 .

[0107] S1112 : forming a first bonding layer 113 and a magnetic film layer 112 in sequence on the side of the polymer film layer 111 away from the supporting substrate 40 .

[0108] During the preparation process, the polymer film layer 111, the first bonding layer 113 and the magnetic film layer 112 are sequentially deposited on the support substrate 40. The specific method of depositing the polymer film layer 111, the first bonding layer 113 and the magnetic film layer 112 is not limited in the present application.

[0109] The function of the first bonding layer 113 is to ensure the firm connection between the polymer film layer 111 and the magnetic film layer 112, and the function of the magnetic film layer 112 is to ensure that the mask layer 110 can be attracted by the magnet 30 during the evaporation process to avoid deformation of the polymer film layer 111. It should be noted that in other embodiments, before forming the magnetic film layer 112, the first bonding layer 113 may not be formed, or in other embodiments, only the polymer film layer 111 may be formed on the supporting substrate 40 without forming the first bonding layer 113 and the magnetic film layer 112.

[0110] S1113: patterning the magnetic film layer 112, the first bonding layer 113 and the polymer film layer 111 in sequence to form a second sub-opening 1121 penetrating the magnetic film layer 112, a third sub-opening 1131 penetrating the first bonding layer 113 and a first sub-opening 1111 penetrating the polymer film layer 111 respectively.

[0111] Specifically, first, photoresist 50 is coated on the magnetic film layer 112 away from the supporting substrate 40 and a pattern is formed by photolithography. Then, the patterned photoresist 50 is used as a mask and the magnetic film layer 112 is processed by wet etching (dry etching can also be used) to form a second sub-opening 1121 that passes through the magnetic film layer 112. Then, the patterned photoresist 50 and the patterned magnetic film layer 112 are used as masks and the first bonding layer 113 is processed by dry etching (wet etching can also be used) to form a third sub-opening 1131 that passes through the first bonding layer 113. Then, the patterned photoresist 50, the patterned magnetic film layer 112 and the patterned first bonding layer 113 are used as masks and the polymer film layer 111 is processed by polymer etching (dry etching or wet etching can also be used) to form a first sub-opening 1111 that passes through the polymer film layer 111. Through the above process, the preparation of the mask layer 110 can be completed.

[0112] In the above embodiment, three etching processes are used to complete the preparation of the first opening 1101, but in other embodiments, only one etching process may be used to etch through the magnetic film layer 112, the first bonding layer 113 and the polymer film layer 111, that is, the magnetic film layer 112, the first bonding layer 113 and the polymer film layer 111 are etched through in the same etching process, or in other embodiments, one etching process may be used to first etch through the magnetic film layer 112 and the first bonding layer 113, and then another etching process may be used to etch through the polymer film layer 111.

[0113] In one embodiment, when the mask layer 110 and the support layer 120 are fixedly connected in step S130, the fixed connection between the mask layer 110 and the support layer 120 can be achieved by a bonding medium. At this time, before the mask layer 110 and the support layer 120 are stacked, a bonding medium is formed on at least one of the mask layer 110 and the support layer 120. After the mask layer 110 and the support layer 120 are stacked, the bonding medium is located between the mask layer 110 and the support layer 120. Then, the connection firmness between the mask layer 110 and the support layer 120 can be ensured by heating reflow soldering. Of course, the heating reflow soldering process can also be omitted. Among them, the bonding medium can include glue, and can also include temporary bonding glue, resin glue, solder, metal, alloy solder and other materials that can be heated and reflow soldered. There is no limitation on the specific material of the bonding medium. In another embodiment, when the mask layer 110 and the support layer 120 are fixedly connected in step S130, a connection method without an adhesive medium can also be used for connection. For example, the connection between the mask layer 110 and the support layer 120 can be achieved by using at least one of mechanical pressing, laser welding and other connection methods without an adhesive medium.

[0114] The above description is only an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A mask plate for forming an evaporation pattern on a target substrate, characterized in that: The mask plate comprises: A mask layer, provided with a plurality of first openings penetrating the mask layer, wherein the first openings correspond to the evaporation pattern, and the mask layer comprises a polymer film layer; The support layer is stacked with the mask layer and is provided with at least one second opening penetrating the support layer, wherein the second opening exposes a plurality of the first openings.

2. The mask plate according to claim 1, characterized in that: The polymer film layer has a thermal expansion coefficient less than or equal to 8 ppm / °C from room temperature to 300°C; Preferably, the polymer film layer has a thermal expansion coefficient of 3 to 5 ppm / °C from room temperature to 300°C; Preferably, the thermal expansion coefficient of the polymer film layer is equal to the thermal expansion coefficient of the target substrate; Preferably, the material of the polymer film layer includes polyimide; Preferably, the thickness of the polymer film layer ranges from 2 to 20 microns; Preferably, the cross section of the first opening parallel to the mask plate is rectangular or rounded rectangular; Preferably, on a plane where a vertical cross section of the first opening is located, a side wall of the first opening extends along a thickness direction of the mask plate; Preferably, the side length of the orthographic projection of the first opening on the target plane is in the range of 3 to 60 micrometers, and the target plane is parallel to the mask plate; Preferably, a plurality of the first openings are exposed from the second opening, wherein the distance between the side wall of the second opening and the outermost side wall of the cluster formed by the plurality of the first openings is in the range of 0.1 to 0.3 mm; Preferably, the cross section of the second opening parallel to the mask plate and the cross section of the first opening parallel to the mask plate have the same shape; Preferably, the cross section of the second opening parallel to the mask plate is rectangular or rounded rectangular; Preferably, on a plane where a vertical cross section of the second opening is located, a side wall of the second opening extends along a thickness direction of the mask plate.

3. The mask plate according to claim 2, characterized in that: The mask layer further comprises: A magnetic film layer, stacked with the polymer film layer and located on a side of the polymer film layer close to the support layer; Preferably, the material of the magnetic film layer includes ferromagnetic material; Preferably, the material of the magnetic film layer includes at least one of nickel, iron, and Invar alloy; Preferably, the thickness of the magnetic film layer ranges from 1 to 20 microns; Preferably, the thermal expansion coefficients of the magnetic film layer and the polymer film layer are equal; Preferably, the mask layer further comprises a first bonding layer, which is disposed between the magnetic film layer and the polymer film layer and is used to bond the magnetic film layer and the polymer film layer; Preferably, the first bonding layer, the magnetic film layer, and the polymer film layer have the same thermal expansion coefficients; Preferably, the material of the first bonding layer includes an inorganic material; Preferably, the material of the first bonding layer includes at least one of amorphous silicon, silicon oxide, and silicon nitride; Preferably, the first adhesive layer is a single-layer structure or a laminated structure; Preferably, the thickness of the first adhesive layer is in the range of 10 to 1000 nanometers.

4. The mask plate according to claim 1, characterized in that: The material of the support layer includes metal; Preferably, the support layer is magnetic; Preferably, the thermal expansion coefficient of the support layer is equal to the thermal expansion coefficient of the mask layer, or the thermal expansion coefficient of the support layer is equal to the thermal expansion coefficient of the target substrate; Preferably, the support layer is a universal metal mask plate; Preferably, the thickness of the support layer ranges from 20 to 100 microns; Preferably, the mask plate further comprises a bonding medium layer, wherein the bonding medium layer is disposed between the mask layer and the support layer and connects the mask layer and the support layer; Preferably, the material of the bonding medium layer includes at least one of temporary bonding glue, resin glue, solder, metal, and alloy solder; Preferably, the mask layer is arranged in contact with the support layer; Preferably, the connection method of the non-adhesive medium includes at least one of mechanical pressing and laser welding.

5. The mask plate according to claim 1, characterized in that: There are multiple second openings, wherein the first openings corresponding to different vapor deposition patterns on the display panels are exposed in different second openings; Preferably, the shapes and sizes of the plurality of second openings are the same; Preferably, a plurality of the second openings are arranged in a matrix.

6. The mask plate according to claim 5, characterized in that: A plurality of the first openings corresponding to the vapor deposition pattern on the same display panel are exposed in the same second opening; Preferably, the vapor deposition pattern includes sub-pixels in a display panel, and the size of the second opening is the same as the size of an effective display area of ​​the display panel; Preferably, the length of the orthographic projection of the second opening on the target plane is in the range of 5 to 400 mm, and the target plane is parallel to the mask plate; Preferably, the width of the orthographic projection of the second opening on a target plane is in the range of 3 to 200 mm, and the target plane is parallel to the mask plate.

7. The mask plate according to claim 5, characterized in that: A plurality of the first openings corresponding to the same display panel evaporation pattern are exposed in different second openings; Preferably, the vapor deposition pattern includes sub-pixels in the display panel, the second openings extend along the first direction, and a plurality of the second openings corresponding to the same display panel are arranged into a plurality of opening rows in the second direction, each of the opening rows includes at least one second opening, wherein the first direction is the same as an extension direction of a pixel row in the display panel, and the second direction is the same as an extension direction of a pixel column in the display panel; Preferably, the row of openings includes one second opening; Preferably, the orthographic projection of the second opening on the target plane includes a first side extending in the first direction and a second side extending in the second direction, wherein the length of the first side is equal to the length of the third side of the effective display area of ​​the display panel, the extension direction of the third side is the same as the extension direction of the pixel row, and the target plane is parallel to the mask plate.

8. The mask according to claim 7, wherein two second openings adjacently arranged in the second direction are respectively defined as a first target opening and a second target opening, a pixel row corresponding to a plurality of the first openings exposed from the first target opening is defined as a first pixel row, a pixel row corresponding to a plurality of the first openings exposed from the second target opening is defined as a second pixel row, and a pixel row located between the first pixel row and the second pixel row is defined as a third pixel row, wherein: The number of the first pixel row, the second pixel row and the third pixel row is equal; Preferably, the plurality of first openings exposed from the second openings correspond to an integer number of sub-pixels in the display panel; Preferably, the plurality of first openings exposed from the second opening correspond to sub-pixels in an integer number of pixel units in the display panel; Preferably, the length of the first side of the second opening is in the range of 5 to 400 mm, and the length of the second side of the second opening is in the range of 0.5 to 5 mm.

9. A mask plate assembly, characterized in that: comprising at least one mask plate according to any one of claims 1 to 8; Preferably, there are multiple mask plates, and the multiple first openings of the multiple mask plates are arranged so that when the multiple mask plates are stacked, the number and arrangement of the multiple exposed first openings are the same as the number and arrangement of the multiple vapor deposition patterns. Preferably, the plurality of mask plates have the same size; Preferably, the evaporation pattern includes sub-pixels in the display panel, and the second openings extend along a first direction in which a pixel row in the display panel extends, and a plurality of the second openings corresponding to the same display panel are arranged into a plurality of opening rows in a second direction in which the pixel column extends, and each of the opening rows includes at least one second opening.

10. A method for preparing a mask plate, characterized in that: The preparation method comprises: Prepare a mask layer, wherein the mask layer is provided with a plurality of first openings penetrating the mask layer, the first openings correspond to the evaporation pattern, and the mask layer includes a polymer film layer; The mask layer and the support layer are stacked, wherein the support layer is provided with at least one second opening penetrating the support layer, and the second opening exposes a plurality of the first openings; The mask layer is fixedly connected to the support layer; Preferably, the step of preparing the mask layer comprises: preparing the mask layer on a supporting substrate; And, the step of stacking the mask layer and the support layer comprises: Placing the support layer on the side of the mask layer away from the support substrate so as to be stacked with the mask layer; And, after the mask layer is fixedly connected to the support layer, the method further comprises: removing the supporting substrate; Preferably, the step of preparing the mask layer on the supporting substrate comprises: forming the polymer film layer on the supporting substrate; Patterning the polymer film layer to form a first sub-opening penetrating the polymer film layer; Preferably, before patterning the polymer film layer to form a first sub-opening penetrating the polymer film layer, the method further includes: forming a magnetic film layer on a side of the polymer film layer away from the supporting substrate; Patterning the magnetic film layer to form a second sub-opening penetrating the magnetic film layer, wherein the second sub-opening is connected to the first sub-opening; Preferably, before forming the magnetic film layer on the side of the polymer film layer away from the supporting substrate, the method further comprises: forming a first bonding layer on a side of the polymer film layer away from the supporting substrate; And, after patterning the magnetic film layer and before patterning the polymer film layer, the method further includes: The first bonding layer is patterned to form a third sub-opening penetrating the first bonding layer, wherein the third sub-opening is connected to the first sub-opening and the second sub-opening.

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