Patent Publication Number: US-2021172047-A1

Title: Mask, preparation method and operation method thereof

Description:
The present application claims priority of Chinese Patent Application No. 201710407553.2 filed on Jun. 2, 2017, the disclosure of which is incorporated herein by reference in its entirety as part of the present application. 
     TECHNICAL FIELD 
     At least one embodiment of the present disclosure relates to a mask, and a preparation method and an operation method thereof. 
     BACKGROUND 
     In a production procedure of various electronic products such as a transistor, a liquid crystal panel, and an Organic Light-Emitting Diode (OLED) panel, a mask is required to prepare a desired pattern. However, during an operation procedure, the mask will damage a the substrate to be coated, and affect the defect-free ratio of evaporation of the substrate. 
     SUMMARY 
     At least one embodiment of the present disclosure provides a mask, which comprises a support and a mask strip mounted on the support, the mask strip comprising at least two connecting portions each connected with the support, and a pattern portion located between the at least two connecting portions, the pattern portion comprising a first outer surface, and the connecting portion comprising a second outer surface; wherein the first outer surface and the second outer surface are non-coplanar with each other. 
     At least one embodiment of the present disclosure provides a method of preparation a mask, which comprises: providing a support and mounting a mask strip on the support; wherein the mask strip comprises at least two connecting portions each connected with the support, and a pattern portion located between the at least two connecting portions, the pattern portion comprises a first outer surface, and each connecting portion comprises a second outer surface; and the second outer surface and the first outer surface are non-coplanar with each other. 
     At least one embodiment of the present disclosure provides an operation method of the afore-mentioned mask, which comprises: placing a substrate on the mask, wherein a surface of the substrate to be coated is in contact with the first outer surface of the mask, and the surface of the substrate to be coated is in non-contact with the second outer surface of the mask. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to clearly illustrate the technical solution of the embodiments of the present disclosure, the drawings of the embodiments will be briefly described in the following; it is obvious that the described drawings are only related to some embodiments of the present disclosure and thus are not limitative of the present disclosure. 
         FIG. 1 a    is a front view of a mask; 
         FIG. 1 b    is a partial top view of the mask shown in  FIG. 1   a;    
         FIG. 1 c    is a side view of the mask shown in  FIG. 1   a;    
         FIG. 2 a    is a structural schematic diagram of a mask provided by an embodiment of the present disclosure; 
         FIG. 2 b    is a cross-sectional view of the mask shown in  FIG. 2 a    along M-N; 
         FIG. 2 c    is a spatial structure diagram of a mask strip in the mask shown in  FIG. 2   b;    
         FIG. 2 d    is a spatial structure diagram of a support in the mask shown in  FIG. 2   b;    
         FIG. 2 e    is a schematic diagram of spatial distribution of a working surface and a mounting surface of a mask strip provided by an embodiment of the present disclosure; 
         FIG. 2 f    is a front view of a mask and a substrate provided by an embodiment of the present disclosure; 
         FIG. 2 g    is a partial structural schematic diagram of a mask provided by an embodiment of the present disclosure; 
         FIG. 2 h    is a partial structural schematic diagram of another mask provided by an embodiment of the present disclosure; 
         FIG. 3  is a structural schematic diagram of a still another mask provided by an embodiment of the present disclosure; 
         FIG. 4  is a structural schematic diagram of a yet another mask provided by an embodiment of the present disclosure; 
         FIG. 5  is a structural schematic diagram of a still another mask provided by an embodiment of the present disclosure; 
         FIG. 6  is a structural schematic diagram of a yet another mask provided by an embodiment of the present disclosure; 
         FIG. 7  is a structural schematic diagram of a still another mask provided by an embodiment of the present disclosure; and 
         FIG. 8  is a structural schematic diagram of a yet another mask provided by an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In order to make objects, technical details and advantages of the embodiments of the disclosure apparent, the technical solutions of the embodiments will be described in a clearly and fully understandable way in connection with the drawings related to the embodiments of the disclosure. Apparently, the described embodiments are just a part but not all of the embodiments of the disclosure. Based on the described embodiments herein, those skilled in the art can obtain other embodiment(s), without any inventive work, which should be within the scope of the disclosure. 
     Unless otherwise defined, all the technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. The terms “first,” “second,” etc., which are used in the description and the claims of the present disclosure, are not intended to indicate any sequence, amount or importance, but distinguish various components. The terms “comprises,” “comprising,” “comprises,” “comprising,” etc., are intended to specify that the elements or the objects stated before these terms encompass the elements or the objects and equivalents thereof listed after these terms, but do not preclude the other elements or objects. The phrases “connect”, “connected”, etc., are not intended to define a physical connection or mechanical connection, but may comprise an electrical connection, directly or indirectly. “On,” “under,” “right,” “left” and the like are only used to indicate relative position relationship, and when the position of the object which is described is changed, the relative position relationship may be changed accordingly. 
     In the embodiments of the present disclosure, the term “pattern portion of a mask” refers to a portion of the mask that comprises a patterned structure of a shielding region and/or a non-shielding region; the term “connecting portion of the mask” refers to a portion connected with or fixed onto a support; and the term “mounting region of the connecting portion” refers to a region where the connecting portion is provided thereon with a connector such as a screw, a pin, a welding spot and a pad. The term “second outer surface” refers to a surface on which the connector is located, and the term “first outer surface” refers to a surface facing the substrate to be coated. In the embodiments of the present disclosure, the terms “second outer surface” and “first outer surface” should be understood to have directionality. For example, in condition that the second outer surface and the first outer surface are two planes parallel to each other and facing a same direction, an included angle between the two planes should be regarded as 180 degrees (for example, as illustrated in  FIG. 4 ); in condition that the second outer surface and the first outer surface are two planes parallel to each other and facing opposite directions, the included angle between the two planes should be regarded as 360 degrees (for example, as illustrated in  FIG. 5 ). 
       FIG. 1 a    is a front view of a mask, and  FIG. 1 b    is a partial top view of the mask shown in  FIG. 1 a   . As shown in  FIG. 1 a    and  FIG. 1 b   , the mask comprises a support  100 ′ and at least one mask strip  200 ′, and each mask strip  200 ′ is fixed onto the support  100 ′ by at least one welding spot  240 ′. During the evaporation process, the mask  100 ′ is disposed on a substrate  300 ′ to be coated, because a height of the welding spot  240 ′ is usually higher than a surface of the mask strip  200 ′, the welding spot  240 ′ will be in direct contact with the substrate  300 ′ and a gap will be formed between the substrate  300 ′ and the mask strip  200 ′, which not only affects fitting closeness between the mask strip  200 ′ and the substrate  300 ′, but also causes evaporation materials to easily accumulate within the gap and hard to remove. In addition, because the welding spot  240 ′ is in direct contact with the substrate  300 ′, in a position corresponding to the welding spot  240 ′ (a connector), the substrate  300 ′ is subjected to a large partial pressure, and is apt to crack, thereby causing cracks occurred in the substrate  300 ′. 
     As shown in  FIG. 1 b   , when the mask strip  200 ′ is subjected to, for example, an external force, and the like, a corner (such as region A in  FIG. 1 b   ) of the mask strip  200 ′ is easily warped, and the warped portion of the mask strip  200 ′ is apt to cause the substrate  300 ′ to be scratched or the damaged substrate  300 ′ in turn causes the mask strip  200 ′ to be scratched, and the warped portion (e.g., the corner) of the mask strip  200 ′ will also increase a distance between the mask strip  200 ′ and the substrate  300 ′. In addition, the mask strip  200 ′ is fixed by the welding spot  240 ′ in a point fixation manner, which is apt to generate a wrinkle  250 ′ in the mask strip  200 ′, and affect the defect-free ratio of evaporation of the substrate  300 ′. 
       FIG. 1 a    is a side view of the mask shown in  FIG. 1 a   . As shown in  FIG. 1 c   , the mask needs to be repaired after the mask strip  200 ′ is replaced, but a portion of the original mask strip  200 ′ fixed by the welding spot  240 ′ needs to be polished, and polishing will cause the support of a corresponding region to be worn. For example, as shown in  FIG. 1 c   , a portion of the support  100 ′ located in a region B is worn to a higher degree, resulting in that the mask strip  200 ′ of the region B is not coplanar with other mask strips  200 ′. If the repairing operation is performed for a plurality of times, flatness of the region of the support  100 ′ for fixing the mask strip  200 ′ will be affected, which further affects evaporation accuracy of the mask. 
     At least one embodiment of the present disclosure provides a mask, and a preparation method and an operation method thereof. The mask comprises a support and a mask strip mounted on the support, the mask strip comprising at least two connecting portions connected with the support, and a pattern portion located between the at least two connecting portions, the pattern portion comprising a first outer surface, the connecting portion comprising a second outer surface, the first outer surface and the second outer surface being non-coplanar with each other. While the mask is disposed on a substrate in evaporation process, the substrate to be coated may be provided on the first outer surface; because the second outer surface of the mask strip is not coplanar with the first outer surface, the second outer surface may be distal to the substrate, and both a warped corner of the mask strip and the connector on the second outer surface will not be in contact with the substrate; in this way, the first outer surface of the mask strip may be closely fitted on the substrate, and the defect-free ratio of evaporation of the substrate may be increased. 
     Hereinafter, the mask, and the preparation method and the operation method thereof according to at least one embodiment of the present disclosure will be described in detail in conjunction with the accompanying drawings. 
       FIG. 2 a    is a structural schematic diagram of a mask provided by an embodiment of the present disclosure;  FIG. 2 b    is a cross-sectional view of the mask of  FIG. 2 a    along M-N;  FIG. 2 c    is a spatial structure diagram of a mask strip in the mask shown in  FIG. 2 b   ; and  FIG. 2 d    is a spatial structure diagram of a support in the mask shown in  FIG. 2   b.    
     As shown in  FIG. 2 a    to  FIG. 2 d   , a mask provided by at least one embodiment of the present disclosure comprises: a support  100  and a mask strip  200  mounted on the support  100 , the mask strip  200  comprising at least two connecting portions  220  connected with the support  100  and a pattern portion  210  located between the connecting portions  220 . For example, the connecting portion  220  comprises a mounting region  230 , and the mask strip  200  is mounted on the support  100  through a connector  240  in the mounting region  230 . The mask strip  200  comprises an upper surface  201  and a lower surface  202  opposite to each other, the pattern portion  210  comprises a first outer surface  2101  provided on the upper surface  201 , and a surface of the mounting region  230  facing away from the support  100  is a second outer surface  2301 , wherein, the second outer surface  2301  and the first outer surface  2101  are non-coplanar with each other, so that the second outer surface  2301  in the mask strip  200  will not be in contact with a substrate, and the connector  240  will not be in contact with the substrate, during evaporation. As compared with  FIG. 1 a   , the mask of the above-described structure eliminates a gap between the mask strip  200 ′ and the substrate  300 ′, and implements close fitting between the first outer surface of the mask strip and the surface of the substrate to be coated, which thus increases the defect-free ratio of evaporation of the substrate. 
     It should be noted that, in at least one embodiment of the present disclosure, a mask strip  200  is not limited to comprising two connecting portions  220 , and may also comprise more than two connecting portions  220 . The number of connecting portions  220  comprised in the mask strip  200  may be decided according to actual needs, which will not be limited in the embodiments of the present disclosure. In order to facilitate explanation of the technical solution according to the embodiments of the present disclosure, the technical solution in the following embodiments of the present disclosure is illustrated, with a case where the mask strip  200  comprises two connecting portions  220  and a pattern portion  210  is provided between the two connecting portions  220  as an example. 
     For example, in at least one embodiment of the present disclosure, as shown in  FIG. 2 a    to  FIG. 2 d   , a support  100  comprises a main body (a portion of the support  100  located in a region  110  in  FIG. 2 d   ) and two side portions provided on two opposite sides of the main body (portions of the support  100  in regions  120  in  FIG. 2 d   ). The main body  110  may be, for example, of a square frame shape, with a rectangular or square opening in the center, and the opening facilitates exposing the mask strip  200  during evaporation. A shape and a size of the opening may be designed according to the number and distribution of the mask strips  200 . For example, the opening may be of a regular shape such as a round shape, an elliptical shape and a polygonal shape, or may be of an irregular shape. For example, in at least one embodiment of the present disclosure, a main body and side portions may be of an integrated structure. A pattern portion  210  of a mask strip  200  is supported by the main body  110 , and two connecting portions  220  of the mask strip  200  are respectively mounted on two side portions  120  of the support  100 . The main body  110  comprises a first main surface  111  and a second main surface  112  opposite to each other, and a side portion  120  comprises a third outer surface  121 . For example, the first main surface  111  is connected with the third outer surface  121 , and the second outer surface  2301  of the mask strip  200  may be provided with a connector  240  which is configured to fix the mask strip  200  onto the support  100 . The mask strip  200  can be fixed onto the support  100  in various modes, for example, a riveting mode with a screw, a pin, and the like, or a welding mode such as electrical arc welding, and the like, which will not be limited in the embodiments of the present disclosure. The pattern portion  210  of the mask strip  200  has a patterned structure; for example, the pattern portion  210  comprises a plurality of shielding regions and a plurality of non-shielding regions; for example, each of shielding region and each of the non-shielding region may be alternately arranged. In a procedure of evaporating with a mask, an evaporation material (a material for evaporation) may pass through the non-shielding region but cannot pass through the shielding region, so after the evaporation material is evaporated and deposited on the substrate, a patterned structure corresponding to the non-shielding region of the mask strip  200  is formed on the substrate. 
     For example, in at least one embodiment of the present disclosure, as shown in  FIG. 2 a   , a main body of a support  100  may be a frame structure having an opening, side portions are portions extending from sides S 1  and S 2  of the frame structure, and the side portions may be used for having a mask strip  200  fixed. It may be understood that, on sides S 3  and S 4  where the mask strip needs not to be fixed, the support  100  may not be provided with the side portions. In at least one embodiment of the present disclosure, structures of a support and a side portion depend on relative positional relationship between a second outer surface and a first outer surface on the mask strip  200 , which will be described in detail in the embodiments below. 
     For example, in at least one embodiment of the present disclosure, a second outer surface of a connecting portion is further away from a substrate with respect to a first outer surface of a pattern portion. For example, the second outer surface is located on a side facing a lower surface of a plane where the first outer surface is located. By providing the second outer surface  2301  and the first outer surface  2101  in the mask strip  200  not coplanar with each other, and providing the second outer surface  2301  distal to a surface of the substrate to be coated, the second outer surface  2301  in the mask strip  200  is prevented from being in contact with the substrate. 
       FIG. 2 e    is a schematic diagram of spatial distribution of a first outer surface and a second outer surface of a mask strip in a mask provided by an embodiment of the present disclosure (in order to facilitate understanding, only a pattern portion  210  and a mounting region  230  in the mask strip  200 , rather than a complete mask strip  200 , is shown in  FIG. 2 e   ). For example, as shown in  FIG. 2 e   , the first outer surface  2101  of the mask strip  200  is, for example, located in a plane P (a plane where the first outer surface  2101  is located), for example, the plane P may be a horizontal plane, and a side N 1  of the horizontal plane P may be provided with a substrate to be coated. The second outer surface  2301  is located on a side N 2  of the plane P (i.e., a side of the plane P facing a lower surface  202 ), and the plane P may serve as an interface between the mask strip  200  and the substrate to be coated. Therefore, the second outer surface  2301  and the first outer surface  2101  are non-coplanar with each other; in this case, a connector  240  located on the second outer surface  2301  will not be in contact with the substrate, and a warped corner of the mask strip  200  will not affect the substrate, and thus, the defect-free ratio of evaporation is increased. 
     Hereinafter, as shown in  FIG. 2 e   , technical solutions in at least one of the following embodiments of the present disclosure will be described, with a case where an included angle Q between a first outer surface  2101  and a second outer surface  2301  in a mask strip  200  is greater than or equal to 180 degrees and less than or equal to 360 degrees as an example. 
       FIG. 2 f    is a front view of a mask and a substrate provided by an embodiment of the present disclosure. For example, in at least one embodiment of the present disclosure, as shown in  FIG. 2 f   , a third outer surface  121  of each side portion  120  of a support  100  may be set as an inclined plane, two connecting portions  220  of a mask strip  200  are mounted on the inclined plane (the third outer surface  121 ) through connectors  240 , and an included angle Q between a second outer surface  2301  and a first outer surface  2101  in the mask strip  200  is greater than 180 degrees and less than 270 degrees. In this case, the second outer surface  2301  of the mask strip  200  will not be in contact with a substrate  300  to be coated, and the connector  240  will not be in contact with the substrate  300  to be coated, which implements close fitting between the first outer surface of the mask strip  200  and the substrate  300 , and may increase the defect-free ratio of evaporation of the substrate  300 . 
     For example, in at least one embodiment of the present disclosure, inclinations of two connecting portions  220  may be the same as or different from each other, which will not be limited in the embodiments of the present disclosure. For example, each mask strip  200  may comprise a first connecting portion and a second connecting portion, and an included angle between a second outer surface of the first connecting portion and the first outer surface  2101  may be same as or different from an included angle between a second outer surface of the second connecting portion and the first outer surface  2101 . Hereinafter, technical solutions the following embodiments of the present disclosure will be described, with a case where the included angle between the second outer surface of the first connecting portion and the first outer surface  2101  and the included angle between the second outer surface of the second connecting portion and the first outer surface  2101  are same as each other an example. 
       FIG. 2 g    is a partial structural schematic diagram of a mask provided by an embodiment of the present disclosure. For example, in at least one embodiment of the present disclosure, a mask strip  200  is fixed onto a support  100  through connectors  240  on second outer surfaces  2301 . Because the connector  240  has a certain height, in at least one embodiment of the present disclosure, with respect to a mask as shown in  FIG. 2 g   , an included angle Q between a second outer surface  2301  and a first outer surface  2101  may be further set according to the height of a connector  240 . As shown in  FIG. 2 g   , in a direction perpendicular to a plane where the second outer surface  2301  is located, the height of the connector  240  is H, and in a direction parallel to the plane where the second outer surface  2301  is located, a distance from the connector  240  to a vertex of an included angle θ is L (the two connectors  240  may have different values of L), as long as θ&gt;arctan(H/L) is satisfied, and because 0=Q-180 degrees, the included angle Q&gt;arctan (H/L)+180 degrees. 
     For example, in at least one embodiment of the present disclosure, as shown in  FIG. 2 g   , since the connecting portion  220  is fixed onto the side portion  120  of a support  100  through the connector  240 , the mask strip  200  is stretched and tightened by the connector  240 , so a portion of the mask strip  200  located at a joint between the connecting portion  220  and a pattern portion  210  may be supported by an edge  140  of the support  100  where a main body  110  and the side portion  120  of the support  100  intersect with each other. That is, the edge  140  of the support  100  may support the portion of the mask strip  200  located at the joint between the connecting portion  220  and the pattern portion  210 , so as to ensure flatness of the pattern portion  210  of the mask strip  200 . As compared with the structure of the mask shown in  FIG. 1 b   , the mode of fixing the mask strip  200  according to the embodiment of the present disclosure is changed from point fixation to linear fixation (the surface morphology of the pattern portion  210  of the mask strip  200  does not no longer depends on the welding spot  240 ′, but depends on the edge  140 ), so that a wrinkle  250 ′ in  FIG. 1 b    may be avoided. Even if the wrinkle  250 ′ appears on a second outer surface  2301 , the above-described structure (the surface morphology of the pattern portion  210  defined by the edge  140 ) may also reduce or eliminate extension of the wrinkle toward the pattern portion  210 . 
     In order to prevent a repairing operation from affecting a fixation position (e.g., the edge  140 ) of the mask strip  200 , the second outer surface  2301  may be set distal to the position of the edge  140  of the support  100 . For example, in at least one embodiment of the present disclosure, in a case where an included angle Q of a second outer surface  2301  and a first outer surface  2101  is greater than 180 degrees and less than 270 degrees, a third outer surface  121  of a side portion  120  of a support  100  may be set in a stair-step shape. In this way, in the procedure of repairing the mask, a repairing operation, for example, a polishing operation will not affect the edge  140 , and accuracy of the mask may be ensured. 
       FIG. 2 h    is a partial structural schematic diagram of another mask provided by an embodiment of the present disclosure. As shown in  FIG. 2 h   , in a case where an included angle Q between a second outer surface  2301  and a first outer surface  2101  of a mask strip  200  is greater than 180 degrees and less than 270 degrees, a third outer surface  121  of a side portion  120  of a support  100  is set in a two-stair-step shape and comprises a first sub-surface  1211 , a second sub-surface  1212 , a third sub-surface  1213  and a fourth sub-surface  1214  that are sequentially connected; the first sub-surface  1211  is connected with a first main surface  111  of a main body  110 . For example, the second outer surface  2301  may be provided on the second sub-surface  1212 , the third sub-surface  1213 , or the fourth sub-surface  1214 , so that polishing the second outer surface  2301  will not affect an edge  140  of the support  100 , while a repairing operation is performed on the mask. 
     For example, the first sub-surface  1211  and the first main surface  111  of the main body  110  intersect with each other to form a first boundary, and the third sub-surface  1213  and the fourth sub-surface  1214  intersect with each other to form a second boundary; an included angle c between a plane defined by the first boundary and the second boundary and the fourth sub-surface  1214  is greater than an included angle b between the third sub-surface  1213  and the fourth sub-surface  1214 . In a case where the included angle c is greater than the included angle b, when the second outer surface  2301  is fixed onto the fourth sub-surface  1214 , a connecting portion of the mask strip  200  (a portion at a joint between a pattern portion  210  and a connecting portion  220 ) is supported by both the edge  140  of the support  100  and an edge where the second sub-surface  1212  and the third sub-surface  1213  intersect with each other, which further achieves fixing and tightening effects on the mask strip  200 , and reduces or eliminates wrinkles. 
     It should be noted that, in at least one embodiment of the present disclosure, the number of stair-steps is not limited when a third outer surface  121  of a side portion  120  of a support  100  is set in a stair-step shape, and the third outer surface  121  of the side portion  120  of the support  100  may also be set in a one-stair-step shape or a multi-stair-step shape, and the like. 
     For example, in at least one embodiment of the present disclosure, an edge  140  where a first main surface  111  of a main body  110  and a third outer surface  121  intersect with each other may be rounded or chamfered (as shown in a region of a dotted-line square  140  in  FIG. 2 h   ). As shown in  FIG. 2 h   , the edge  140  of a support  100  may be set as a cambered surface having a certain camber (e.g., greater than 0 degree and less than 45 degrees). The edge  140  of the support  100  may affect surface morphology of a pattern portion  210  in a mask strip  200 , a partial region of the mask strip  200  (e.g., a joint between a pattern portion  210  and a connecting portion  220 ) will be subjected to a relatively large force if supported by the edge  140 , and the edge  140  is set to have a round corner structure so that it has a cambered surface, which may prevent the edge  140  from slashing the mask strip  200  because the edge  140  is too sharp (with partial stress concentrated). 
     In at least one embodiment of the present disclosure, a shape of a third outer surface  121  of a side portion  120  of a support  100  is not limited. For example, in a case where an included angle between a second outer surface  2301  and a first outer surface  2101  is greater than 180 degrees and less than 270 degrees, the third outer surface  121  of the side portion  120  of the support  100  and the second outer surface  2301  of the mask strip  200  are conformal, for example, both are cambered surfaces, or of other curved shapes, and the like.  FIG. 3  is a structural schematic diagram of a still another mask provided by an embodiment of the present disclosure. As shown in  FIG. 3 , a third outer surface  121  of a side portion  120  of a support  100  is a cambered surface, so that a second outer surface  2301  provided on the third outer surface  121  is also a cambered surface accordingly, as long as an included angle Q between a tangent line of the second outer surface  2301  having a cambered shape and a first outer surface  2101  is greater than 180 degrees and less than 270 degrees, and thus, the second outer surface  2301  is not coplanar with the first outer surface  2101 , and the second outer surface  2301  is not in contact with the substrate  300 . 
     For example, in at least one embodiment of the present disclosure, as shown in  FIG. 3 , at an end portion of a third outer surface  121  proximal to a first main surface  111 , a tangent line of the third outer surface  121  is substantially parallel to the first main surface  111 . In this way, the third outer surface  121  and the first main surface  111  are substantially smoothly connected with each other, which not only prevents an edge  140  from slashing a mask strip  200  because the edge  140  is too sharp (with partial stress concentrated), but also allows both portions of the connecting portion  220  located at the pattern portion  210  and the second outer surface  2301  to be supported by the third outer surface  121 , so as to further prevent a wrinkle from extending toward the pattern portion  210 , even if the wrinkle appears in the second outer surface  2301 . 
       FIG. 4  is a structural schematic diagram of a yet another mask provided by an embodiment of the present disclosure. As shown in  FIG. 4 , an included angle Q between a second outer surface  2301  and a first outer surface  2101  is 180 degrees, for example, the first outer surface  2101  and the second outer surface  2301  are parallel to each other and provided in different horizontal planes. A specific shape of a support  100  may be set according to positional relationship between the first outer surface  2101  and the second outer surface  2301 . For example, in at least one embodiment of the present disclosure, as shown in  FIG. 4 , a side portion  120  of a support  100  has a groove. For example, a groove D may be provided on a first main surface  111  of the support  100 , and a second outer surface  2301  of a mask strip  200  may be provided in the groove D. It should be noted that, in a direction perpendicular to a plane where the second outer surface  2301  is located, a depth of the groove D may be determined according to actual needs, as long as the depth of the groove D may allow a connector  240  on the second outer surface  2301  not to be in contact with a the substrate to be coated. For example, the depth of the groove D is greater than a height of the connector  240 . In one example, the depth of the groove D may be greater than about 10 microns, for example, the depth of the groove D ranges from 10 microns to 20 microns. In this way, the second outer surface  2301  of the mask strip  200  will not be in contact with the substrate  300  to be coated, and the first outer surface  2101  of the mask strip  200  and the substrate  300  may be closely fitted to each other, so as to increase the defect-free ratio of evaporation of the substrate  300 . 
       FIG. 5  is a structural schematic diagram of a still another mask provided by an embodiment of the present disclosure. For example, in a mask provided in at least one embodiment of the present disclosure, as shown in  FIG. 5 , an included angle Q between a second outer surface  2301  and a first outer surface  2101  is 360 degrees, for example, the first outer surface  2101  and the second outer surface  2301  are parallel to each other and provided in different horizontal planes. A specific shape of a support  100  may be set according to positional relationship between the first outer surface  2101  and the second outer surface  2301 . For example, in at least one embodiment of the present disclosure, a side portion  120  of a support  100  may be in strip-shape. For example, a second outer surface  2301  of a mask strip  200  may be provided on a lower surface of the side portion  120  of the support  100  (a surface on a side of the side portion  120  distal to a pattern portion  210 ). In this case, the second outer surface  2301  of the mask strip  200  will not be in contact with a substrate  300  to be coated, and the connector  240  on the second outer surface  2301  will not be in contact with the substrate, which may increase the defect-free ratio of evaporation of the substrate  300 . 
       FIG. 6  is a structural schematic diagram of a yet another mask provided by an embodiment of the present disclosure. For example, in a mask provided in at least one embodiment of the present disclosure, as shown in  FIG. 6 , an included angle Q between a second outer surface  2301  and a first outer surface  2101  of a mask strip  200  is 270 degrees. For example, a third outer surface  121  of a side portion  120  of a support  100  may be a vertical plane, i.e., a plane where the third outer surface  121  is located is perpendicular to a first main surface  111  of the support  100 . In this case, the second outer surface  2301  of the mask strip  200  will not be in contact with a substrate  300  to be coated, and the connector  240  on the second outer surface  2301  will not be in contact with the substrate  300 , which may increase the defect-free ratio of evaporation of the substrate  300 . 
       FIG. 7  is a structural schematic diagram of a still another mask provided by an embodiment of the present disclosure. For example, in a mask provided in at least one embodiment of the present disclosure, as shown in  FIG. 7 , an included angle Q between a second outer surface  2301  and a first outer surface  2101  of a mask strip  200  is greater than 270 degrees and less than 360 degrees. For example, a third outer surface  121  of a side portion  120  of a support  100  may be a plane which is inclined inward (e.g., inclined from an edge of a main body  110  toward the interior of the main body  110 ), an included angle between the inclined plane and a first main surface  111  of the support  100  may be between 270 degrees and 360 degrees, and the second outer surface  2301  of the mask strip  200  may be provided on the inclined plane. In this case, the second outer surface  2301  of the mask strip  200  will not be in contact with the substrate  300  to be coated, and a connector  240  on the second outer surface  2301  will not be in contact with the substrate  300 , which may increase the defect-free ratio of evaporation of the substrate  300 . 
     It should be noted that, in the foregoing embodiments, in a case where the included angle between the second outer surface  2301  and the first outer surface  2101  of the mask strip  200  is 180 degrees, or greater than 270 degrees and less than or equal to 360 degrees, the surface of the support  100  for having the second outer surface  2301  fixed may not be limited to a flat plane, but may also be of a cambered shape, and the like, and contents of the embodiment shown in  FIG. 2 h    may be referred to for a specific structure thereof, which will not be repeated here in the present disclosure. 
     It should be noted that, in the mask provided in at least one embodiment of the present disclosure, the included angle between the first outer surface  2101  and the second outer surface  2301  of the mask strip  200  will not be limited, and the included angle between the two will not be limited to that between 180 degrees and 360 degrees, as long as the second outer surface  2301  and the first outer surface  2101  are non-coplanar with each other, and the second outer surface  2301  is located on a side of the first outer surface  2101  distal to the surface of the substrate  300  to be coated, so that in the evaporation procedure, the second outer surface will not be in contact with the substrate to be coated, and the defect-free ratio of evaporation of the substrate may be increased. 
       FIG. 8  is a structural schematic diagram of a yet another mask provided by an embodiment of the present disclosure. For example, in a mask provided in at least one embodiment of the present disclosure, as shown in  FIG. 8 , a groove E is provided on a first main surface  111  of a support  100 , an inclined surface is provided in the groove E, the second outer surface  2301  of the mask strip  200  is provided on the inclined surface; and in a structure of the mask as shown in  FIG. 8 , an included angle Q between the second outer surface  2301  and a first outer surface  2101  may be between 0 degree and 180 degrees. 
     In at least one embodiment of the present disclosure, materials for preparing a support  100  and a mask strip  200  in a mask will not be limited. For example, in at least one embodiment of the present disclosure, materials for preparing a support  100  and a mask strip  200  may comprise a metal material, so that the mask strip  200  may be fixed onto the support  100 , for example, by welding, which is convenient to operate with low process difficulty. 
     At least one embodiment of the present disclosure provides a preparation method of a mask, the preparation method comprising: providing a support and mounting a mask strip on the support; wherein the mask strip comprises at least two connecting portions connected with the support, and a pattern portion located between the at least two connecting portions, the mask strip comprises an upper surface and a lower surface opposite to each other, the pattern portion comprises a first outer surface provided on the upper surface, and the connecting portion comprises a second outer surface provided on the upper surface; the second outer surface and the first outer surface are non-coplanar with each other, and the second outer surface is located on a side of the first outer surface proximal to the lower surface. The foregoing embodiments may be referred to for a specific structure of the mask, which will not be repeated here. 
     With the mask prepared by using the preparation method according to at least one embodiment of the present disclosure, when the substrate is being coated with the mask, the second outer surface of the mask strip will not be in contact with the substrate, so that a warped corner of the mask strip and a connector (for fixing the mask strip) on the second outer surface, etc., will not affect fitting closeness between the mask strip and the substrate, which may increase the defect-free ratio of evaporation. 
     At least one embodiment of the present disclosure provides an operation method of a mask, the method comprising: placing a the substrate to be coated on a mask, wherein a surface of the substrate to be coated is in contact with a first outer surface of the mask, and the surface of the substrate to be coated is not in contact with a second outer surface of the mask. For a specific structure of the mask, related description in the foregoing embodiments (the embodiments with respect to the mask) may be referred to, and the specific structure of the mask will not be limited in the present disclosure. 
     The mask in the above-described embodiment may allow the mask strip and the substrate to be coated to be fitted closely to each other, and in this way, it may be considered that the surface of the substrate to be coated is coplanar with the first outer surface of the pattern portion of the mask strip; because the second outer surface and the first outer surface of the mask strip in the mask are non-coplanar with each other, and the second outer surface is located on a side of the first outer surface proximal to a lower surface of the mask strip, the second outer surface of the mask strip will not be in contact with the surface of the substrate to be coated, which may increase the defect-free ratio of evaporation. 
     For example, in at least one embodiment of the present disclosure, a surface of a substrate to be coated and a second outer surface are non-coplanar with each other, and an included angle between the two is greater than or equal to 180 degrees and less than or equal to 360 degrees. For example, the included angle between the surface of the substrate to be coated and the second outer surface of the mask comprises: 180 degrees, greater than 180 degrees and less than 270 degrees, 270 degrees, greater than 270 degrees and less than 360 degrees, or 360 degrees, and the like. For specific structures of the mask in different angular ranges as described above, contents in the foregoing embodiments may be referred to, which will not be repeated here. 
     The embodiments of the present disclosure provide the mask, the preparation method and the operation method thereof, and may have at least one of advantageous effects below: 
     (1) At least one embodiment of the present disclosure provides a mask, and in the mask, the second outer surface of the mask strip is not coplanar with the first outer surface, and is located on the same side of the plane where the first outer surface is located, so that the second outer surface is not in contact with the substrate to be coated, which may increase the defect-free ratio of evaporation of the substrate. 
     (2) In the mask provided by at least one embodiment of the present disclosure, as compared with the current structure, the mode of fixing the mask strip in the mask according to the embodiment of the present disclosure is changed from point fixation to linear fixation, which may reduce or eliminate the wrinkle problem in the mask strip, and may further increase evaporation accuracy of the substrate. 
     (3) In the mask provided by at least one embodiment of the present disclosure, the edge of the support for supporting the surface morphology of the evaporation region of the mask strip may be designed to be rounded or chamfered, which may prevent the mask strip from being slashed; the third outer surface of the side portion of the support is designed as a stair-step shape, which, in the procedure of repairing the mask, may prevent the edge of the support from being abraded by the polishing operation, so as to ensure precision of the mask. 
     With respect to the present disclosure, several points below need to be explained: 
     (1) The drawings of the embodiments of the present disclosure relate only to the structures involved in the embodiments of the present disclosure, and normal designs may be referred to for other structures. 
     (2) For the sake of clarity, in the drawings used for describing the embodiments of the present disclosure, thicknesses of layers or regions are enlarged or reduced, that is, these drawings are not drawn in an actual scale. 
     (3) In case of no conflict, the embodiments of the present disclosure and the features in the embodiments may be combined with each other to obtain a new embodiment. 
     What is described above is related to the illustrative embodiments of the disclosure only and not limitative to the scope of the disclosure; the scopes of the disclosure are defined by the accompanying claims.