CN104317158B - A kind of mask plate, mask plate group, color membrane substrates and display device - Google Patents

Abstract

The invention provides a mask, a mask group, a color film substrate and a display device, relates to the field of display technology, and solves the problem of irregular shapes caused by the overlapping of color film layer position accuracy marks and the reduction of the position accuracy mark size , to ensure the accuracy of the degree of relative positional deviation between the obtained color resistance and the black matrix. The mask plate is used to form the color filter layer, including four sets of color filter layer position accuracy identification graphics located at the four corners of the mask plate, and each set of color filter layer position accuracy identification graphics includes parallel, horizontally arranged and longitudinally The two bar-shaped color filter layer position accuracy identification graphics, the horizontal dimension of the color filter layer position accuracy identification graphic is a, and a is smaller than the width of one sub-pixel.

Description

Mask plate, mask plate group, color filter substrate and display device

technical field

The invention relates to the field of display technology, in particular to a mask, a mask group, a color filter substrate and a display device.

Background technique

The color filter substrate in the display generally includes: a glass substrate, and a black matrix layer and a color filter layer formed on the glass substrate, wherein the black matrix layer includes a grid formed by interlacing rows of black matrix bars and columns of black matrix bars The black matrix structure, the color filter layer includes a plurality of color resists arranged in a matrix, and the arrangement of the color resists in each row is arranged in the order of red, green and blue as a repeating unit. Usually, the edge of the color resist overlaps with the black matrix strips by a certain width to prevent light leakage from the edge of the color resist.

At present, when forming the black matrix layer, four groups of black matrix position accuracy marks will be formed on the same layer at the four corners of the substrate. Each group includes three square black matrix position accuracy marks with a pitch of one sub-pixel width. When forming the color filter layer, it will Four sets of color filter layer position accuracy marks are formed at the four corners of the substrate. Each group includes three color filter layer position accuracy marks of red, green, and blue with a spacing of one sub-pixel width. The size is larger than the size of the black matrix position accuracy mark, and the color filter layer position accuracy mark covers or frames the black matrix position accuracy mark. By detecting the degree of deviation between the midpoint of the position accuracy mark of the black matrix and the position accuracy mark of the color filter layer, the degree of deviation of the relative position of the black matrix and the color resist is detected to check whether the edge of the color resist overlaps with the black matrix strip.

In the prior art, processes such as coating, exposure, development, and baking are usually used to form the color resists of different colors in the color filter layer respectively. Since the color resists of different colors in the color filter layer are arranged in the same way, the color resists of different colors are formed in the color filter layer. The same mask can be used for color resistance.

However, as people's requirements for display resolution are getting higher and higher, the width of sub-pixels is getting smaller and smaller, and the distance between the black matrix position accuracy marks in the same group is getting smaller and smaller, which leads to the final formation of the same group The position accuracy marks of the red, green, and blue color film layers with larger sizes overlap, and it is impossible to accurately obtain the deviation degree of the relative position of the color resistance and the black matrix.

If the size of the black matrix and the position accuracy mark of the color filter layer are both reduced with the pixel size, although the problem of overlapping position accuracy marks of the color film layer can be avoided, the position accuracy mark of the color film layer and the position accuracy mark of the black matrix with too small size The shape is not easy to control during production, and it will become irregular, resulting in inaccurate reading of the position coordinates of the position accuracy mark of the color filter layer and the position accuracy mark of the black matrix, and thus it is impossible to accurately obtain the deviation degree of the relative position of the color resistance and the black matrix.

Contents of the invention

Based on the status quo of the above-mentioned prior art, the technical problem to be solved by the present invention is: to provide a mask, a mask set, a color filter substrate and a display device to solve the problem of overlapping and shrinking positions of color filter layer position accuracy marks. The problem of the irregular shape of the position precision mark caused by the size of the precision mark ensures the accuracy of the relative position deviation between the obtained color resistance and the black matrix.

To achieve the above object, the present invention adopts the following technical solutions:

The first aspect of the present invention provides a mask plate for forming a color filter layer in a display device, the color filter layer corresponds to a plurality of pixel units, and each of the pixel units on the color filter layer has a Color resists of n colors arranged laterally, the mask plate includes four sets of color filter layer position accuracy identification patterns respectively located at the four corners of the mask plate, and each group of color filter layer position accuracy identification patterns includes parallel to each other . Two stripe-shaped color filter layer position accuracy identification patterns arranged laterally and extending vertically. The horizontal dimension of the color filter layer position accuracy identification pattern is a, and a is smaller than the width of one sub-pixel.

Preferably, the distance between the longitudinal centerlines of the two color filter layer position accuracy identification patterns at one corner of the mask plate is e, and the ratio of e to the width of a sub-pixel is greater than n.

Preferably, the mask plate further includes: a matrix-like color-resist pattern located in the middle region of the mask plate.

Preferably, a is greater than or equal to 35 μm, and the width of one sub-pixel is less than or equal to 65 μm.

A second aspect of the present invention provides a mask set, including: a first mask, the first mask being the above-mentioned mask for forming a color filter layer in a display device; The second mask, the second mask is used to form the black matrix layer in the display device, including four groups of black matrix position accuracy identification patterns respectively located at the four corners of the second mask, each group of The black matrix position accuracy identification graphics include n black matrix position accuracy identification graphics arranged in the horizontal direction, the distance between the longitudinal centerlines of two adjacent black matrix position accuracy identification graphics is the width of one sub-pixel, and the black matrix position accuracy identification graphics The horizontal dimension of the precision identification pattern is d, and d is less than the width of a sub-pixel; when the parts corresponding to the display area of the first mask and the second mask overlap, the first mask at the same corner The center line of the center line of the position accuracy identification graphics of the two color filter layers of the board coincides with the longitudinal center line of the first black matrix position accuracy identification graphic of the n black matrix position accuracy identification graphics of the second mask plate, And if the distance between the longitudinal midlines of the two color filter layer position accuracy marking patterns at one corner of the first mask plate is e, then the ratio of e to the width of a sub-pixel is greater than 2n.

Preferably, the second mask further includes: a grid-structured black matrix pattern located in the middle region of the second mask.

Preferably, d is greater than or equal to 20 μm, and the width of one sub-pixel is less than or equal to 65 μm.

Preferably, n is equal to 3 or 4.

The third aspect of the present invention provides a color filter substrate, including: a substrate; a black matrix layer formed on the substrate, and the black matrix layer uses the second mask in the above-mentioned mask group Formed, the black matrix layer includes four groups of black matrix position accuracy marks respectively located at the four corners of the black matrix layer; the color filter layer formed on the substrate, the color filter layer utilizes the above-mentioned mask plate The first mask plate in the group is formed, and the color filter layer includes four sets of color filter layer position accuracy marks respectively located at the four corners of the color filter layer; The arrangement of the position accuracy marks of the black matrix is as follows: n color film layer position accuracy marks with different colors, n black matrix position accuracy marks, and n color film layer position accuracy marks with different colors in sequence along the horizontal direction Arrangement, the spacing between the longitudinal centerlines of two adjacent color filter layer position accuracy marks and the longitudinal centerline distance between two adjacent black matrix position accuracy marks are both the width of one sub-pixel.

Preferably, the shortest distance between the color filter layer position accuracy mark and the black matrix position accuracy mark at the same corner is greater than zero, there is a gap between two adjacent color filter layer position accuracy marks at the same corner, and the same corner There is a gap between two adjacent black matrix position accuracy marks.

Preferably, the n color filter layer position accuracy marks with different colors are respectively a red color film layer position accuracy mark, a green color film layer position accuracy mark and a blue color film layer position accuracy mark; or, each of the colors The n different color film layer position accuracy marks are respectively the red color film layer position accuracy mark, the green color film layer position accuracy mark, the blue color film layer position accuracy mark and the yellow color film layer position accuracy mark; or, the color The n different color film layer position accuracy marks are respectively the red color film layer position accuracy mark, the green color film layer position accuracy mark, the blue color film layer position accuracy mark and the white color film layer position accuracy mark.

Preferably, the black matrix layer further includes a grid-structured black matrix located in the middle region of the black matrix layer; the color filter layer further includes color resists arranged in a matrix in the middle region of the color filter layer.

A fourth aspect of the present invention provides a display device, including the above-mentioned color filter substrate.

The mask plate, mask plate group, color filter substrate and display device provided by the present invention set the color filter layer position accuracy identification patterns of each group on the mask plate used to form the color filter layer to include parallel and Two bar-shaped color filter layer position accuracy identification graphics extending along the column direction, since the graphics forming the color filter layer position accuracy identification are bar-shaped, the shape of the bar graphics is easy to control, so the color filter layer position accuracy identification can be set Narrower and more regular in shape, thereby avoiding the problem of irregular shapes caused by the overlapping of the position accuracy marks of the color filter layer and the reduction of the size of the position accuracy marks, so that the coordinates of the position accuracy marks of the color filter layer can be accurately read in the end, and then obtained The exact degree of deviation of the relative positions of the black matrix and the color resist.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is a plan view of a mask plate used to form a color filter layer provided by an embodiment of the present invention;

Fig. 2 is the plane structural diagram of the mask plate that is used to form black matrix layer that the embodiment of the present invention provides;

FIG. 3 is a plan view of the partial overlap of the corresponding display regions of the first mask and the second mask in the mask set provided by the embodiment of the present invention;

4a to 4d are step diagrams of the forming process of the black matrix position accuracy mark and the color filter layer position accuracy mark in the process of manufacturing the color filter substrate by using the mask plate set provided by the embodiment of the present invention.

Detailed ways

In order to make the above objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

An embodiment of the present invention provides a mask, the structure of which is shown in Figure 1. The mask is used to form a color filter layer in a display device. The color filter layer corresponds to a plurality of pixel units. Each pixel unit has color resists of n colors arranged horizontally, and the mask plate includes four groups of color filter layer position accuracy identification patterns respectively located at the four corners of the mask plate, and each group of color filter layer position accuracy identification patterns includes parallel, Two stripe-shaped color filter layer position accuracy identification patterns 1 arranged horizontally and extending vertically, if the horizontal dimension of the color filter layer position accuracy identification pattern 1 is a, then a is smaller than the width of one sub-pixel.

Since the position accuracy mark of the color filter layer is bar-shaped, the shape of the bar figure is easier to control than the original square and frame shapes. The shape of the film layer position accuracy mark will also be relatively regular, that is, the formed color film layer position accuracy mark can be set narrower and more regular in shape, thereby avoiding the overlap of the color film layer position accuracy mark caused by the reduction of the sub-pixel width And the problem of the irregular shape of the position accuracy mark caused by reducing the size of the position accuracy mark is that the coordinates of the position accuracy mark of the color filter layer formed by the mask provided by this embodiment can be accurately read, thereby ensuring that it can be accurately obtained. The degree of deviation of the relative position of the black matrix and the color resistance.

In this embodiment, if the distance between the longitudinal midlines of the two color filter layer position accuracy identification patterns 1 at one corner of the mask plate is e, then the ratio of e to the width of a sub-pixel is greater than n, so as to ensure the use of the There is no overlap between the position accuracy marks of the color filter layer formed by the mask plate.

The mask plate also includes: matrix-like color-resist patterns 2 located in the middle area of the mask plate. Specifically, the area AA where the color resistance pattern 2 is located corresponds to the display area of the display device; since the edge of the color resistance can overlap with the black matrix strips in order to avoid light leakage at the edge of the color resistance pattern 2, the width of each color resistance pattern 2 can be slightly larger than The width of one sub-pixel; if the mask plate is used to manufacture n color resists in the same color filter layer, the distance between adjacent color resist patterns 2 is n-1 times the width of one sub-pixel.

In this embodiment, for a display device in which the width of one sub-pixel is less than or equal to 65 μm, the lateral dimension a of the color filter layer position accuracy identification pattern 1 is preferably greater than or equal to 35 μm, so as to ensure that the formed color filter layer position The accuracy marks are not too fine, and a good control of the shape of the position accuracy marks of the color filter layer is achieved.

It should be noted that the width of the sub-pixel in this embodiment refers to the lateral dimension of the sub-pixel.

The embodiment of the present invention also provides a mask set, the mask set includes: a first mask, the first mask is the above-mentioned mask for forming the color filter layer in the display device Membrane, its structure is as shown in Figure 1; The second mask, this second mask is used to form the black matrix layer in the display device, as shown in Figure 2, including the four corners of the second mask respectively The four groups of black matrix position accuracy identification graphics, each group of black matrix position accuracy identification graphics include n black matrix position accuracy identification graphics 3 arranged in the horizontal direction, between two adjacent black matrix position accuracy identification graphics 3 along the longitudinal centerline The pitch p is the width of a sub-pixel, and the lateral dimension of the black matrix position accuracy logo 3 is d, and d is smaller than the width of a sub-pixel; as shown in Figure 3, the parts AA and When the part AA of the corresponding display area of the second mask plate coincides, the position accuracy of the two color filter layers of the first mask plate at the same corner marks the center line of the center line of figure 1 and the n black matrix positions of the second mask plate The first black matrix position accuracy identification pattern in the accuracy identification pattern 3 coincides with the longitudinal centerline, and if the distance between the two color filter layer position accuracy identification patterns 1 along the longitudinal centerline at one corner of the first mask plate is e, then the ratio of e to a sub-pixel width p is greater than 2n, more specifically: e/p>2n.

Taking n equal to 3 (that is, each pixel unit includes 3 sub-pixels), and the colors of the color resistance to be formed include three colors of red (R), green (G) and blue (B) as an example, using the above mask The specific process of making the black matrix layer and the color filter layer can be as follows: first, the second mask plate is covered on the substrate to form a black matrix layer, and each of the four corners of the formed black matrix layer has a set of black matrix layers as shown in Figure 4a. The matrix position accuracy mark 5, the distance between two adjacent black matrix position accuracy marks 5 is p; then the first mask plate is covered on the substrate to form a red color resist layer, and the four corners of the formed red color resist layer are uniform There are two red color film layer position accuracy marks 6 as shown in Figure 4b, the distance between the two is the distance e between the two color film layer position accuracy marks 1 in the same group on the first mask plate; A mask moves to the right along the lateral direction by a distance of a pixel width p to form a green color-resist layer on the substrate, and the four corners of the formed green color-resist layer have two green color filter layer position accuracy as shown in Figure 4c Mark 7, the distance between the two is e; then move the first mask to the right along the horizontal direction for a distance of a pixel width p, and form a blue color-resist layer on the substrate, and the four corners of the formed blue color-resist layer have two A blue color filter layer position accuracy mark 8 as shown in Figure 4d, the distance between the two is e. It should be noted that this implementation only takes the formation order of the red color-resist layer, the green color-resist layer and the blue color-resist layer as an example, and the color filter layers may also be formed in other order.

After completing the production of the black matrix layer and the color filter layer, it is necessary to detect the deviation degree of the relative position of the black matrix in the black matrix layer and the color resistance in the color filter layer, and obtain the overlap between the edge of each color resistance and the black matrix strip situation to judge whether there is light leakage around the color resist. The aforementioned detection is realized by detecting the degree of deviation of the relative positions of the black matrix position accuracy mark 5 and the color filter layer position accuracy marks 6 , 7 and 8 . Specifically, read the coordinates of the position accuracy marks 6 of the two red color film layers to obtain the midpoint of the line connecting the centers of the two, and detect the degree of deviation between the midpoint and the midpoint of the first black matrix position accuracy mark, similarly Detect the degree of deviation between the midpoint of the center line of the position accuracy mark 7 of the two green color film layers and the midpoint of the second black matrix position accuracy mark, and the difference between the midpoint of the center line of the position accuracy mark 8 of the two blue color film layers The degree of deviation of the midpoint of the third black matrix position accuracy mark 5, thereby obtaining the degree of deviation of the relative position of the position accuracy mark of the color filter layer at one corner and the relative position of the black matrix position accuracy mark, and similarly obtaining the positions of the remaining three corners The degree of deviation of the relative position of the position accuracy mark of the color filter layer and the position accuracy mark of the black matrix.

In the prior art, although the spacing between the three black matrix position accuracy marks in the same group is set to twice the sub-pixel width, the problem of overlapping position accuracy marks of the color filter layer can be eliminated, and it is not necessary to reduce the position The size of the precision mark, but if the same mask is still used to form the color filter layer, it is necessary to move the distance of two sub-pixels when making color resists of different colors, which results in a vacancy of the color resist at the edge of the display area, so this The method requires two masks, one is used to form red and blue color resists, and the other is used to form green color resists, which not only increases the cost, but also complicates the manufacturing steps of the color filter substrate. Once the mask used to form the green color resist is damaged, production will not be possible. It is not difficult to find from the above process of making the black matrix layer and the color filter layer by using the mask set provided in this embodiment that the mask used to form the color filter layer provided in this embodiment can not only avoid sub-pixel width The problem of the overlapping of the position accuracy mark of the color film layer caused by the reduction and the irregular shape of the position accuracy mark of the color film layer caused by reducing the size of the position accuracy mark of the color film layer, and the use of the same mask to form the color film The color resistance of the three colors of the layer avoids the use of two mask plates to make the color film layer, thereby saving costs, simplifying the manufacturing steps of the color film substrate, and eliminating the mask used to form the green color resistance in the prior art. The problem that the production cannot be carried out due to the damage of the membrane plate.

In this embodiment, the second mask further includes: a grid-structured black matrix pattern 4 located in the middle region of the second mask, for forming a grid-structured black matrix.

In this embodiment, since the width of the color filter layer position accuracy identification pattern 1 on the first mask plate can be set narrower, the mask set provided in this embodiment is compared with the mask plate in the prior art. It is more suitable for the production of color filter substrates with high resolution (that is, sub-pixels with narrower widths). Specifically, for display devices with sub-pixels whose width is less than or equal to 65 μm, the horizontal size of the black matrix position accuracy identification pattern in this implementation d can be greater than or equal to 20 μm, so that the size of the black matrix position accuracy marking pattern is not too small, and the shape of the formed black matrix position accuracy mark is guaranteed to be regular.

The colors of the sub-pixels in the display device usually include three or four colors. Based on this, n in this embodiment is preferably equal to 3 or 4, so that the number of black matrix position accuracy identification patterns 3 included at one corner of the second mask plate Also 3 or 4.

In addition, the width a of the color filter layer position accuracy identification pattern 1 included in the first mask plate may be equal to or different from the width d of the black matrix position accuracy identification pattern 3, which can be designed according to actual conditions.

It should be noted that the pattern included in the mask plate and mask plate set provided in this embodiment can be a light-shielding area or a light leakage area. If a negative photoresist is used for exposure, the mask plate and The patterns included in the mask plate set are light leakage areas, and if a positive photoresist is used for exposure, the mask plate and the patterns included in the mask plate set are light-shielding areas.

This embodiment also provides a color filter substrate, including: a substrate; a black matrix layer formed on the substrate, the black matrix layer is formed by using the second mask in the mask group provided in this embodiment, including Four sets of black matrix position accuracy marks respectively located at the four corners of the black matrix layer; the color filter layer formed on the substrate, the color filter layer is formed by using the first mask in the mask set provided in this embodiment, including Four sets of color filter layer position accuracy marks located at the four corners of the color film layer; as shown in Figure 4d, the arrangement of the color film layer position accuracy marks and the black matrix position accuracy marks at the same corner is: n Color filter layer position accuracy marks (6, 7, 8), n black matrix position accuracy marks (5), and n color film layer position accuracy marks (6, 7, 8) of different colors are arranged in sequence along the horizontal direction The distance between the longitudinal centerlines of two adjacent color filter layer position accuracy marks and the longitudinal centerline distance between two adjacent black matrix position accuracy marks is the width p of one sub-pixel.

The color filter substrate provided in this embodiment is produced by using the mask set provided in this embodiment, so the deviation degree of the color resistance in the color filter layer and the relative position of the black matrix in the black matrix layer can be detected by detecting the position of the color filter layer. The relative position of the precision mark and the position precision mark of the black matrix is obtained accurately, which ensures the alignment accuracy of the color resist and the black matrix, and improves the yield rate of the color filter substrate.

In Figure 4d, a represents the lateral dimension of the position accuracy mark of the color filter layer (that is, the width of the position accuracy mark of the color film layer), b represents the distance between two adjacent color film layer position accuracy marks, and c represents the color film layer The shortest distance between the location precision mark and the black matrix position precision mark, f represents the spacing between two adjacent black matrix position precision marks, then the width p=a+b=d+f of a sub-pixel, thus guaranteed Using the same mask plate to move the distance of one sub-pixel width each time can complete the production of all the color resists of the color filter layer. The distance between two color filter layer position accuracy marks of the same color at one corner of the color film layer along the longitudinal centerline (that is, the two color film layer position accuracy marks included in the same group of color film layer position accuracy marks on the first mask plate The spacing between the longitudinal midlines of the layer position accuracy marks) e=3a+2b+2c+3d+2f, so as to ensure that the finally formed position accuracy marks are arranged as shown in Figure 3d.

The shortest distance c between the color filter layer position accuracy mark and the black matrix position accuracy mark along the longitudinal centerline at the same corner can be greater than zero, and there can be a gap between two adjacent color film layer position accuracy marks at the same corner (ie b >0), there is a gap between two adjacent black matrix position accuracy marks at the same corner (ie f>0), so as to ensure accurate reading of the position accuracy marks. Further, b and f may be equal or unequal, and the values of b and f may be specifically set to be greater than or equal to 7 μm, so as to ensure that the formed color filter layer position accuracy marks do not overlap.

According to the different colors of the sub-pixels included in the display device (such as: including three colors of R, G, B, or including four colors of R, G, B, Y (yellow), or including R, G, B, W (white) four colors), in this embodiment, the n color film layer position accuracy marks with different colors located at the same end of the black matrix position accuracy mark at the same corner can be respectively red color film layer position accuracy mark, green color film layer position accuracy mark layer position accuracy identification and blue color film layer position accuracy identification; or red color film layer position accuracy identification, green color film layer position accuracy identification, blue color film layer position accuracy identification and yellow color film layer position accuracy identification; or red color film layer position accuracy identification Color film layer position accuracy identification, green color film layer position accuracy identification, blue color film layer position accuracy identification, and white color film layer position accuracy identification; or change accordingly according to the color of the sub-pixel to ensure the detection of all color color resistance positions .

In this embodiment, the black matrix layer further includes a grid-structured black matrix located in the middle region of the black matrix layer; the above-mentioned color filter layer further includes matrix-like color resists located in the middle region of the color filter layer.

This embodiment also provides a display device, which includes the above-mentioned color filter substrate. Since the yield rate of the mask plate is higher than that of the prior art, the display device including the color filter substrate also has a higher yield rate.

It should be noted that the display device provided in this embodiment can be a liquid crystal panel, an electronic paper or an OLED (Organic Light-Emitting Diode, organic light-emitting diode) panel, which is suitable for mobile phones, tablet computers, televisions, monitors, notebook computers, Any product or component with display function, such as digital photo frame and navigator.

The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention are all Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (12)

1. A mask plate, used to form a color filter layer in a display device, the color filter layer corresponds to a plurality of pixel units, and each pixel unit on the color filter layer has n kinds of colors arranged horizontally The color resistance is characterized in that the mask plate includes four groups of color filter layer position accuracy identification patterns located at the four corners of the mask plate, and each group of color filter layer position accuracy identification patterns includes parallel to each other, along the Two stripe-shaped color filter layer position accuracy identification patterns arranged horizontally and extending longitudinally, the horizontal dimension of the color filter layer position accuracy identification pattern is a, and a is less than the width of one sub-pixel; where n is equal to 3 or 4. 2. The mask plate according to claim 1, characterized in that, the distance between the longitudinal centerlines of the two color filter layer position accuracy identification patterns at one corner of the mask plate is e, e and a sub- The ratio of pixel widths is greater than n. 3 . The mask according to claim 1 , further comprising: a color-resist pattern arranged in a matrix in a middle region of the mask. 4 . 4 . The mask according to claim 1 , wherein a is greater than or equal to 35 μm, and the width of one sub-pixel is less than or equal to 65 μm. 5. A mask plate group, characterized in that, comprising: A first mask, the first mask being the mask for forming the color filter layer in the display device according to any one of claims 1 to 4; The second mask, the second mask is used to form the black matrix layer in the display device, including four groups of black matrix position accuracy identification patterns respectively located at the four corners of the second mask, each group of The black matrix position accuracy identification graphics include n black matrix position accuracy identification graphics arranged in the horizontal direction, the distance between the longitudinal centerlines of two adjacent black matrix position accuracy identification graphics is the width of one sub-pixel, and the black matrix position accuracy identification graphics The horizontal dimension of the precision identification graphic is d, and d is less than the width of one sub-pixel; When the parts corresponding to the display area of the first mask plate and the second mask plate overlap, the center line of the center line of the two color filter layers of the first mask plate at the same corner and the center line of the mark graphic center line Among the n black matrix position accuracy identification patterns of the second mask plate, the first black matrix position accuracy identification pattern coincides along the longitudinal centerline, and if the two color filters at one corner of the first mask plate The distance between the midlines of the layer position accuracy identification graphics along the longitudinal direction is e, and the ratio of e to the width of a sub-pixel is greater than 2n. 6 . The mask set according to claim 5 , wherein the second mask further comprises: a grid-structured black matrix pattern located in a middle region of the second mask. 7. The mask set according to claim 5 or 6, wherein d is greater than or equal to 20 μm, and the width of one sub-pixel is less than or equal to 65 μm. 8. A color filter substrate, characterized in that it comprises: Substrate; A black matrix layer formed on the substrate, the black matrix layer is formed using the second mask in the mask set according to any one of claims 5 to 7, the black matrix layer includes Four groups of black matrix position accuracy marks at the four corners of the black matrix layer; The color filter layer formed on the substrate, the color filter layer is formed by using the first mask plate in the mask plate set according to any one of claims 5 to 7, the color filter layer includes Four groups of color filter layer position accuracy marks at the four corners of the color filter layer; Wherein, the arrangement of the position accuracy marks of the color filter layer and the position accuracy marks of the black matrix at the same corner is: n color film layer position accuracy marks with different colors, n black matrix position accuracy marks, color The different n color filter layer position accuracy marks are arranged in sequence along the horizontal direction, the distance between the longitudinal centerlines of two adjacent color film layer position accuracy marks and the longitudinal centerline of two adjacent black matrix position accuracy marks The distance between them is the width of one sub-pixel. 9. The color filter substrate according to claim 8, wherein the shortest distance between the color filter layer position accuracy mark and the black matrix position accuracy mark at the same corner is greater than zero, and two adjacent positions at the same corner There is a gap between the position accuracy marks of the color filter layer, and there is a gap between two adjacent black matrix position accuracy marks at the same corner. 10. The color filter substrate according to claim 8, wherein the n color filter layer position accuracy marks with different colors are respectively a red color film layer position accuracy mark, a green color film layer position accuracy mark and The position accuracy mark of the blue color film layer, where n is equal to 3; or, The n color film layer position accuracy marks with different colors are respectively the red color film layer position accuracy mark, the green color film layer position accuracy mark, the blue color film layer position accuracy mark and the yellow color film layer position accuracy mark, wherein n equals 4; or, The n color film layer position accuracy marks with different colors are respectively red color film layer position accuracy mark, green color film layer position accuracy mark, blue color film layer position accuracy mark and white color film layer position accuracy mark, wherein n is equal to 4. 11. The color filter substrate according to claim 8, wherein the black matrix layer further comprises a grid-structured black matrix located in the middle region of the black matrix layer; The color filter layer further includes color resists arranged in a matrix in the middle region of the color filter layer. 12. A display device, comprising the color filter substrate according to any one of claims 8-11.