Alignment mark structure, substrate, mask plate, and alignment method of substrate and mask plate

Abstract

The present invention relates to the field of flat panel display technology, and discloses an alignment mark structure, a substrate, a mask plate, and an alignment method for a substrate and a mask plate. The alignment mark structure is arranged on a substrate or a mask plate, and the alignment mark structure comprises an alignment mark and a light-transmitting hole opened on the alignment mark. The alignment mark structure, substrate, mask plate, and an alignment method for a substrate and a mask plate provided by the present invention can improve the alignment accuracy of the alignment mark and the position accuracy between the substrate and the mask plate, thereby ensuring the product yield.

Description

Technical Field

[0001] The present invention relates to the technical field of flat panel displays, and in particular to an alignment mark structure, a substrate, a mask plate, and an alignment method for the substrate and the mask plate. Background Art

[0002] The exposure process is to expose the glass substrate with a mask plate with patterns after the photoresist is applied, and transfer the required patterns from the mask plate to the glass substrate. When using an exposure machine for exposure, in order to ensure the accuracy of exposure, it is necessary to make alignment marks on the glass substrate and the mask plate, and pre-align according to the alignment marks before exposure to ensure the position accuracy of the glass substrate and the mask plate during exposure.

[0003] In the prior art, the alignment mark of the glass substrate is also covered with an opaque film layer. The presence of the opaque film layer will affect the recognition effect of the alignment mark, resulting in the image sensor being unable to obtain a clear alignment mark image, thereby affecting the alignment accuracy and position accuracy between the glass substrate and the mask. In addition, when a multi-layer circuit pattern needs to be made on the glass substrate, it is necessary to repeatedly align. For the exposure process, it is necessary to ensure the alignment accuracy between each film layer to avoid the occurrence of overlapping errors between the multi-layer film layers and ensure the product yield. Summary of the invention

[0004] The object of the present invention is to provide an alignment mark structure, a substrate, a mask plate, and an alignment method for the substrate and the mask plate, so as to solve the problem of poor alignment accuracy of the alignment mark.

[0005] To solve the above problems, in a first aspect, the present invention discloses an alignment mark structure, which is arranged on a substrate or a mask plate. The alignment mark structure includes an alignment mark and a light-transmitting hole opened on the alignment mark.

[0006] In one embodiment, the light-transmitting hole includes at least one dot-shaped hole or a strip-shaped hole, and the light-transmitting hole extends along at least a portion of an edge of the alignment mark.

[0007] In one embodiment, the alignment mark is in the shape of a square, a rectangle, a triangle or a cross.

[0008] In the alignment mark structure provided by the present invention, by setting a light-transmitting hole on the alignment mark, the boundary of the alignment mark can be increased, so that the color of the alignment mark under the same light source is darker, so that the image sensor can recognize a clearer alignment mark image and obtain the accurate position information of the alignment mark, effectively improving the alignment accuracy of the alignment mark.

[0009] In a second aspect, the present invention discloses a substrate, on which the alignment mark structure described in the first aspect is provided.

[0010] The substrate provided by the present invention can increase the boundary of the alignment mark by opening a light-transmitting hole on the alignment mark of the substrate, so that the color of the alignment mark presented under the same light source is darker, so that the image sensor can recognize a clearer alignment mark image and obtain accurate position information of the alignment mark, effectively improving the alignment accuracy of the alignment mark and reducing the product defective rate caused by inaccurate alignment in the substrate manufacturing process.

[0011] In a third aspect, the present invention discloses a mask plate, on which the alignment mark structure as described in the first aspect is provided.

[0012] The mask plate provided by the present invention can increase the boundary of the alignment mark by opening a light-transmitting hole on the alignment mark of the mask plate, so that the color of the alignment mark presented under the same light source is darker, so that the image sensor can recognize a clearer alignment mark image and obtain accurate position information of the alignment mark, effectively improving the alignment accuracy of the alignment mark, ensuring that a circuit pattern can be formed at a preset position of the substrate during subsequent exposure, thereby improving the yield rate of the substrate product.

[0013] In a fourth aspect, the present invention discloses a method for aligning a substrate and a mask plate, the method comprising:

[0014] Providing a substrate, on which a first alignment mark and a first light-transmitting hole are provided, and on which an opaque film layer covering the first alignment mark and the first light-transmitting hole is further provided;

[0015] Providing a mask plate, wherein a second alignment mark is provided on the mask plate;

[0016] adjusting light source parameters of the image sensor according to the reflectivity of the opaque film layer;

[0017] The image sensor is used to obtain position information of the substrate, and the mask is adjusted according to the position information of the substrate so that the second alignment mark is positioned opposite to the first alignment mark.

[0018] In one embodiment, the alignment method further includes:

[0019] Providing an auxiliary alignment film layer, wherein the auxiliary alignment film layer is disposed above the opaque film layer;

[0020] Using a back exposure technique, forming an auxiliary alignment mark and an auxiliary light-transmitting hole having the same structure and position as the first alignment mark and the first light-transmitting hole on the auxiliary alignment film layer;

[0021] Acquiring the position information of the substrate by using the image sensor, and adjusting the mask according to the position information of the substrate so that the second alignment mark is positioned opposite to the first alignment mark, comprising:

[0022] The image sensor is used to obtain the position coordinates of the auxiliary alignment mark to obtain the position information of the substrate, and the mask is adjusted according to the position information of the substrate to make the second alignment mark face the auxiliary alignment mark, and further make the second alignment mark face the first alignment mark.

[0023] In one embodiment, if the reflectivity of the opaque film layer is greater than 50%, adjusting the light source parameters of the image sensor includes: adjusting the brightness of the light source of the image sensor to 25%-35% of the maximum brightness.

[0024] In one embodiment, if the reflectivity of the opaque film layer is 30%-50%, adjusting the light source parameters of the image sensor includes: adjusting the brightness of the light source of the image sensor to 55%-65% of the maximum brightness.

[0025] In one embodiment, if the reflectivity of the opaque film layer is less than 30%, adjusting the light source parameters of the image sensor includes: adjusting the brightness of the light source of the image sensor to 85%-95% of the maximum brightness.

[0026] In one embodiment, when providing a mask plate, if the reflectivity of the opaque film layer is greater than or equal to 30%, a second light-transmitting hole is opened on the second alignment mark of the mask plate.

[0027] In one embodiment, a plurality of first alignment marks are disposed on the substrate, a plurality of second alignment marks are disposed on the mask plate, and the plurality of first alignment marks correspond to the plurality of second alignment marks one by one.

[0028] The method for aligning a substrate and a mask provided in an embodiment of the present invention can effectively eliminate the negative impact of the opaque film layer by improving the alignment marks on the substrate and the mask plate and adjusting the light source parameters of the graphic sensor according to the opaque film layer of the substrate, so that the image sensor can obtain clear images of the first alignment mark and the second alignment mark, and can obtain accurate position information of the first alignment mark and the second alignment mark, thereby effectively improving the alignment accuracy between the first alignment mark and the second alignment mark and the position accuracy between the substrate and the mask plate, thereby improving the product yield of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0030] Figure 1 A schematic structural diagram of an alignment mark structure provided by an embodiment of the present invention;

[0031] Figure 2 A schematic structural diagram of another alignment mark structure provided by an embodiment of the present invention;

[0032] Figure 3 for Figure 1 and Figure 2 Schematic diagram of alignment of two alignment mark structures shown;

[0033] Figure 4 for Figure 1 A schematic structural diagram of the alignment mark in the alignment mark structure;

[0034] Figure 5 for Figure 2 A schematic structural diagram of an alignment mark in the alignment mark structure shown;

[0035] Figure 6 for Figure 1 A schematic diagram of a structure in which an alignment mark structure is arranged on a substrate;

[0036] Figure 7 for Figure 2 A schematic diagram of the structure in which the alignment mark structure is arranged on the mask plate;

[0037] Figure 8 One of the flow charts of the method for aligning a substrate and a mask provided in an embodiment of the present invention;

[0038] Fig. 9 The second flowchart of the method for aligning a substrate and a mask provided in an embodiment of the present invention.

[0039] Description of main component symbols:

[0040] 1. Alignment mark structure; 11. Alignment mark; 12. Light-transmitting hole. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0042] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the patent. The terms "first" and "second" are only used for the convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0043] In a first aspect, the present invention provides an alignment mark structure, which can be disposed on a substrate and a mask plate to assist the substrate and the mask plate in alignment. Figure 1 and Figure 2 As shown, the alignment mark structure 1 includes an alignment mark 11 and a light-transmitting hole 12 opened on the alignment mark 11 .

[0044] When the above-mentioned alignment mark structure 1 is provided on a substrate or a mask plate, it is arranged on a light-transmitting layer or a semi-light-transmitting layer. Among them, the alignment mark 11 on the substrate can be made of an organic resin material such as black resin, and the alignment mark on the mask plate can be made of an opaque material, such as a metal material such as chromium. The light-transmitting hole 12 is a through hole provided on the alignment mark 11 and capable of penetrating the alignment mark 11. When a light source is irradiated on a substrate or a mask plate provided with the alignment mark structure 1, the alignment mark structure 1 appears dark, and the position where the alignment mark structure 1 or other patterns are not provided appears white. The alignment mark 11 can be identified by an image sensor and the position information of the alignment mark 11 can be obtained, so that the alignment mark 11 can be used for alignment. In the alignment mark structure 1 provided by the present invention, by setting a light-transmitting hole 12 on the alignment mark 11, the boundary of the alignment mark 11 can be increased, so that the color of the alignment mark 11 under the same light source is darker, so that the image sensor can recognize a clearer image of the alignment mark 11 and obtain the accurate position information of the alignment mark 11, thereby effectively improving the alignment accuracy of the alignment mark 11.

[0045] It should be noted that the alignment mark 11 is made of an opaque material. The lower the transmittance of the opaque material, the higher its blackness under light, the more obvious the alignment mark 11, the clearer the image detected by the image sensor, and the easier it is to align with high alignment accuracy. In addition, the alignment mark structure 1 is initially set on the mask plate, and the alignment mark structure 1 on the substrate is formed by transferring from the previous mask plate through the previous photolithography process.

[0046] In the alignment mark structure 1 provided by the present invention, the type and arrangement of the light-transmitting hole 12 are not unique. For example, in some embodiments, the light-transmitting hole 12 can be one or more strip-shaped holes opened on the alignment mark 11, and the multiple strip-shaped holes can be arranged in parallel, or can be arranged in sequence along the edge of the alignment mark 11 and combined into a pattern with the same shape as the alignment mark 11. Alternatively, in some embodiments, the light-transmitting hole 12 can also be a plurality of dot-shaped holes opened on the alignment mark 11, and the plurality of dot-shaped holes are arranged at intervals and extend along the edge of the alignment mark 11. The type and arrangement of the light-transmitting hole 12 can be designed according to the shape of the alignment mark 11 and the alignment accuracy requirements, and are not limited here.

[0047] In the alignment mark structure 1 provided by the present invention, the shape of the alignment mark 11 is also not unique. For example, in some embodiments, Figure 1 As shown, the alignment mark 11 may be in the shape of a cross. Alternatively, in some embodiments, as Figure 2 As shown, the alignment mark 11 may be a square. Alternatively, in some embodiments, the alignment mark 11 may also be a rectangle, a triangle or other shapes that can be used for alignment, which may be specifically designed according to the shapes of the substrate and the mask or the alignment accuracy requirements, and is not limited here.

[0048] Furthermore, the size of the alignment mark structure 1 is not unique. In one embodiment, the alignment mark structure 1 includes a cross-shaped alignment mark 11 and two groups of cross-shaped light-transmitting holes 12, each group of light-transmitting holes 12 is composed of two vertically arranged bar holes, the centers of the two groups of light-transmitting holes 12 coincide with the center of the alignment mark 11, and the two groups of light-transmitting holes 12 are of different sizes, and the distances between the two groups of light-transmitting holes and the edge of the alignment mark 11 are 0.01 mm and 0.02 mm, respectively. In one embodiment, the alignment mark structure 1 includes a square alignment mark 11 and two groups of square light-transmitting holes 12, each group of light-transmitting holes 12 is composed of four bar holes, the centers of the two groups of light-transmitting holes 12 coincide with the center of the alignment mark 11, and the two groups of light-transmitting holes 12 are of different sizes, and the distances between the two groups of light-transmitting holes and the edge of the alignment mark 11 are 0.01 mm and 0.02 mm, respectively. The above are only two embodiments provided by the present invention, but are not limited thereto. The actual structure and size of the alignment mark 11 and the light-transmitting hole 12 can be designed according to the substrate or the mask plate.

[0049] For ease of understanding, Figure 1 and Figure 2 As shown in FIG. 1 , it is a schematic diagram of the structure of the alignment mark structure 1 provided in an embodiment of the present invention, and a light-transmitting hole 12 is provided on the alignment mark 11. Figure 4 and Figure 5 As shown in FIG. 1 , it is a schematic diagram of the structure of the alignment mark 11, and no light-transmitting hole 12 is provided on the alignment mark 11. Figure 3 As shown, it is a schematic diagram of the alignment of two groups of alignment mark structures 1 with different structures.

[0050] In a second aspect, the present invention provides a substrate, on which is disposed the alignment mark structure 1 as in the first aspect, wherein the substrate may be a glass substrate, a quartz substrate or a transparent resin substrate.

[0051] When the alignment mark structure 1 is set on the substrate, the alignment mark structure 1 needs to be arranged on a light-transmitting layer or a semi-light-transmitting layer. The alignment mark 11 on the substrate can be made of an organic resin material such as black resin. The light-transmitting hole 12 is set on the alignment mark 11 and penetrates the alignment mark 11.

[0052] The substrate provided by the present invention is provided with the alignment mark structure 1 as in the first aspect. When the light source is irradiated on the substrate, the alignment mark 11 is dark in color, and the position without the alignment mark 11 or other patterns is white. In this way, the alignment mark 11 can be identified by a graphic sensor and the position information of the alignment mark 11 can be obtained, so that the alignment mark 11 can be used for alignment. The alignment mark 11 of the above-mentioned substrate is also provided with a light-transmitting hole 12. By providing the light-transmitting hole 12, the boundary of the alignment mark 11 can be increased, so that the color of the alignment mark 11 presented under the same light source is darker, so that the image sensor can identify a clearer image of the alignment mark 11 and obtain accurate position information of the alignment mark 11, effectively improving the alignment accuracy of the alignment mark 11 and reducing the defective rate of products caused by inaccurate alignment in the substrate manufacturing process.

[0053] It should be noted that the alignment mark structure 1 is initially formed on the mask plate, and in this embodiment, the alignment mark structure 1 on the substrate is formed by transferring from the mask plate through a photolithography process. Figure 6 As shown, the alignment mark structure 1 is usually arranged at the edge of the substrate. In addition, to improve the alignment accuracy, multiple sets of alignment mark structures 1 can be arranged on the substrate, wherein the shapes of the multiple sets of alignment mark structures 1 can be the same or different, and the multiple sets of alignment mark structures 1 can be adjacent but not intersecting.

[0054] In a third aspect, the present invention provides a mask plate, on which is disposed the alignment mark structure 1 as in the first aspect. The mask plate can use quartz glass with high transmittance and low reflectivity as a substrate.

[0055] When setting the alignment mark structure 1 on the mask plate, the alignment mark structure 1 needs to be arranged on the light-transmitting layer or the semi-transmitting layer. The alignment mark 11 is made of opaque material, such as metal materials such as chromium, and the light-transmitting hole 12 is set on the alignment mark 11 and penetrates the alignment mark 11.

[0056] The mask plate provided by the present invention is provided with the alignment mark structure 1 as in the first aspect. When the light source is irradiated on the mask plate, the alignment mark 11 is dark, and the position without the alignment mark 11 or other patterns is white. In this way, the alignment mark 11 can be identified by a graphic sensor and the position information of the alignment mark 11 can be obtained, so that the alignment mark 11 can be used for alignment. The alignment mark 11 of the above-mentioned mask plate is also provided with a light-transmitting hole 12. By providing the light-transmitting hole 12, the boundary of the alignment mark 11 can be increased, so that the color of the alignment mark 11 under the same light source is darker, so that the image sensor can identify a clearer image of the alignment mark 11 and obtain accurate position information of the alignment mark 11, effectively improving the alignment accuracy of the alignment mark 11, ensuring that a circuit pattern can be formed at a preset position of the substrate during subsequent exposure, and improving the substrate product yield.

[0057] It should be noted that the mask plate also has a circuit pattern for exposure. To avoid damaging the integrity of the circuit pattern, Figure 7 As shown, the alignment mark structure 1 is usually arranged at the edge of the mask plate. In addition, in order to improve the alignment accuracy, multiple sets of alignment mark structures 1 can be arranged on the mask plate, wherein the shapes of the multiple sets of alignment mark structures 1 can be the same or different, and the positions of the multiple sets of alignment mark structures 1 on the mask plate correspond one-to-one to the positions of the multiple sets of alignment mark structures 1 on the substrate.

[0058] In a fourth aspect, the present invention provides a method for aligning a substrate and a mask plate, which is used to improve the alignment accuracy and position accuracy between the substrate and the mask plate. Figure 8 As shown, the alignment method includes:

[0059] S100: providing a substrate, on which a first alignment mark and a first light-transmitting hole opened on the first alignment mark are disposed, and an opaque film layer covering the first alignment mark and the first light-transmitting hole is also disposed on the substrate.

[0060] The substrate may be a glass substrate, a quartz substrate or a transparent resin substrate. The opaque film layer may be a metal film layer with low transparency, or may be a photoresist coated on the surface of the substrate.

[0061] The first alignment mark needs to be arranged on the light-transmitting layer or the semi-light-transmitting layer. The first alignment mark can be made of an organic resin material such as black resin. The light-transmitting hole 12 is arranged on the alignment mark 11 and penetrates the alignment mark 11 .

[0062] The first light-transmitting hole is arranged on the first alignment mark, so that the color of the first alignment mark presented under the same light source is darker, and the first alignment mark is clearer.

[0063] S200: providing a mask plate, on which a second alignment mark is provided.

[0064] The mask plate can use quartz glass with high transmittance and low reflectivity as a substrate.

[0065] The second alignment mark is disposed on the quartz glass, and the second alignment mark is made of an opaque material, such as a metal material such as chrome.

[0066] S300: adjusting the light source parameter of the image sensor according to the reflectivity of the opaque film layer, wherein the light source parameter may be the light source brightness.

[0067] The higher the reflectivity of the opaque film layer, the lower its transmittance, that is, the higher the opacity. By adjusting the light source parameters of the image sensor according to the reflectivity of the opaque film layer, the blackness of the first alignment mark on the substrate under the illumination of the light source can be increased, effectively eliminating the negative impact of the opaque film layer, so that the image sensor can obtain a clearer first alignment mark image.

[0068] S400: using an image sensor to obtain position information of the substrate, and adjusting the mask according to the position information of the substrate so that the second alignment mark is positioned opposite to the first alignment mark.

[0069] The position information of the substrate may include the center coordinates of the first alignment mark of the substrate. The image sensor may be a CCD camera.

[0070] In the method for aligning a substrate and a mask provided by an embodiment of the present invention, by setting a first alignment mark on the substrate and setting a first light-transmitting hole on the first alignment mark, the boundary of the first alignment mark can be increased, so that the color presented by the first alignment mark under the same light source is darker, and the negative effects of the opaque film layer are effectively eliminated. In addition, the above method also includes adjusting the light source parameters of the image sensor according to the reflectivity of the opaque film layer. By adjusting the light source parameters, the blackness of the first alignment mark under the light source can be increased, and the negative effects of the opaque film layer can be further eliminated. In summary, when the alignment method provided by the present invention is used for alignment, the negative effects of the opaque film layer can be effectively eliminated, so that the image sensor can obtain clear images of the first alignment mark and the second alignment mark, and can obtain accurate position information of the first alignment mark and the second alignment mark, thereby effectively improving the alignment accuracy between the first alignment mark and the second alignment mark and the position accuracy between the substrate and the mask plate, and improving the product yield of the substrate.

[0071] Furthermore, when the above method is used to manufacture a product with a multi-layer circuit pattern, the alignment error between the film layers on the substrate is small, and the fitting error between different circuit layers is also small.

[0072] It is understood that in order to ensure recognition accuracy, the shapes of the first alignment mark on the substrate and the second alignment mark on the mask plate may be different. For example, in some embodiments, the first alignment mark on the substrate may be designed as a cross (e.g. Figure 6 As shown), the second alignment mark on the mask plate can be designed as a square (as shown Figure 7 When aligning, the positions of the substrate and the mask plate can be adjusted so that the second alignment mark is placed on the first alignment mark, and the center coordinates of the first alignment mark and the second alignment mark coincide with each other (as shown in FIG. Figure 3 shown).

[0073] The thickness of the first alignment mark will also affect its blackness under the illumination of the light source. Specifically, the smaller the thickness of the first alignment mark, the smaller its blackness under the illumination of the light source, and the blurrier the image of the first alignment mark detected by the image sensor. To solve the above problem, when the thickness of the first alignment mark is small, an auxiliary alignment film layer can be set between the substrate and the mask plate, and the auxiliary film layer can be used to assist the substrate and the mask plate in alignment. In one embodiment provided by the present invention, Fig. 9 As shown, the alignment method also includes:

[0074] S101: providing an auxiliary alignment film layer, wherein the auxiliary alignment film layer is disposed above the opaque film layer.

[0075] It can be understood that in order to ensure that the subsequent exposure process can be carried out normally, the auxiliary alignment film layer can be made of a transparent material.

[0076] S102: using a back exposure technology, forming an auxiliary alignment mark and an auxiliary light-transmitting hole on the auxiliary alignment film layer, the auxiliary alignment mark and the auxiliary light-transmitting hole having the same structure and position as the first alignment mark and the first light-transmitting hole.

[0077] In the above steps, the substrate is used as a mask plate for the auxiliary alignment film layer for back exposure, so that the first alignment mark and the first light-transmitting hole on the substrate can be directly transferred to the auxiliary alignment film layer, and auxiliary alignment marks and auxiliary light-transmitting holes that are exactly the same as the first alignment marks and the first light-transmitting holes are formed on the auxiliary film layer.

[0078] To ensure the alignment effect of the auxiliary alignment mark, optionally, the thickness of the auxiliary alignment mark is greater than 1 μm.

[0079] S103: Using an image sensor to obtain the position coordinates of the auxiliary alignment mark to obtain the position information of the substrate, and adjusting the mask according to the position information of the substrate so that the second alignment mark is opposite to the first alignment mark. Specifically, using an image sensor to obtain the position coordinates of the auxiliary alignment mark to obtain the position information of the substrate, and adjusting the mask according to the position information of the substrate so that the second alignment mark is opposite to the auxiliary alignment mark, and then the second alignment mark is opposite to the first alignment mark.

[0080] Since there is no overlay error between the auxiliary alignment film layer and the substrate, and the auxiliary alignment mark is opposite to the first alignment mark, when the second alignment mark is opposite to the auxiliary alignment mark, it is also opposite to the first alignment mark.

[0081] The auxiliary alignment film layer is relatively thick. Under the same light source, the auxiliary alignment mark has a high blackness, and the auxiliary alignment mark is adjacent to the mask plate and is not affected by the opaque film layer. The image sensor can detect a clear image of the auxiliary alignment mark and obtain the accurate position information of the auxiliary alignment mark, thereby introducing the auxiliary alignment film layer for alignment, which can effectively improve the alignment accuracy between the first alignment mark and the second alignment mark and the position accuracy between the substrate and the mask plate, thereby improving the product yield of the substrate.

[0082] It should be noted that when the auxiliary alignment film layer is used for alignment, in order to ensure that the auxiliary alignment mark is aligned with the first alignment mark, the position of the mask plate should be adjusted and the second alignment mark on the mask plate should be aligned with the auxiliary alignment mark on the auxiliary alignment film layer.

[0083] Optionally, when the thickness of the first alignment mark on the substrate is less than 1 μm, an auxiliary alignment film layer and the auxiliary alignment mark may be introduced for alignment. Meanwhile, to ensure the alignment effect of the auxiliary alignment mark, the thickness of the auxiliary alignment mark is greater than 1 μm.

[0084] The brightness of the light source of the image sensor will also affect the display effect of the first alignment mark and the second alignment mark. The higher the reflectivity of the opaque film layer, the lower the required light source brightness; the lower the reflectivity of the opaque film layer, the higher the required light source brightness. Therefore, the light source parameters can be adjusted according to the reflectivity of the opaque film layer to improve the clarity of the first alignment mark and the second alignment mark. Specifically, adjusting the light source parameters includes the following situations:

[0085] A: If the reflectivity of the opaque film layer is greater than 50%, adjusting the light source parameters of the image sensor includes: adjusting the light source brightness of the image sensor to 25%-30% of the maximum brightness.

[0086] Under the above light source conditions, the first alignment mark and the second alignment mark are black, and the positions on the substrate and the mask plate where no alignment mark or other patterns are provided are white, so that the image sensor can obtain clear images of the first alignment mark and the second alignment mark.

[0087] B: If the reflectivity of the opaque film layer is 30%-50%, adjusting the light source parameters of the image sensor includes: adjusting the light source brightness of the image sensor to 55%-65% of the maximum brightness.

[0088] Under the above light source conditions, the first alignment mark and the second alignment mark are black, and the positions on the substrate and the mask plate where no alignment mark or other patterns are provided are white, so that the image sensor can obtain clear images of the first alignment mark and the second alignment mark.

[0089] Furthermore, in order to ensure the blackness of the first alignment mark under the illumination of the light source, the density of the first light-transmitting holes on the first alignment mark may be relatively increased during the design.

[0090] C: If the reflectivity of the opaque film layer is less than 30%, adjusting the light source parameters of the image sensor includes: adjusting the light source brightness of the image sensor to 85%-95% of the maximum brightness.

[0091] Under the above light source conditions, the first alignment mark and the second alignment mark are black, and the positions on the substrate and the mask plate where no alignment mark or other patterns are provided are white, so that the image sensor can obtain clear images of the first alignment mark and the second alignment mark.

[0092] The above-mentioned alignment method can eliminate some of the negative effects caused by the opaque film layer by adjusting the brightness of the light source, and improve the blackness of the first alignment mark under the illumination of the light source, so that the image sensor can obtain clear images of the first alignment mark and the second alignment mark, and can obtain the precise position information of the first alignment mark and the second alignment mark, thereby effectively improving the alignment accuracy between the first alignment mark and the second alignment mark and the position accuracy between the substrate and the mask plate, thereby improving the product yield of the substrate.

[0093] Optionally, when the thickness of the first alignment mark is greater than 1 μm, the clarity of the first alignment mark and the second alignment mark may be improved by adjusting the brightness of the light source.

[0094] To further improve the alignment accuracy of the first alignment mark and the second alignment mark, in one embodiment provided by the present invention, when providing a mask plate, if the reflectivity of the opaque film layer is greater than or equal to 30%, a second light-transmitting hole is provided on the second alignment mark of the mask plate. If the reflectivity of the opaque film layer is greater than or equal to 30%, the brightness of the light source is relatively low. At this time, in order to ensure the clarity of the second alignment mark, a second light-transmitting hole may be provided on the second alignment mark of the mask plate.

[0095] It should be noted that the light transmittance of the opaque film layer of the substrate is known information, and whether a second light-transmitting hole needs to be set on the mask plate is known before alignment. Therefore, opening a second light-transmitting hole is a process for making the mask plate. The above-mentioned alignment method does not include the step of opening a second light-transmitting hole. It is only necessary to select a mask plate with a second light-transmitting hole.

[0096] To ensure the alignment effect of the substrate and the mask plate, in an embodiment provided by the present invention, a plurality of first alignment marks are provided on the substrate, a plurality of second alignment marks are provided on the mask plate, and the plurality of first alignment marks and the plurality of second alignment marks correspond to each other. Providing a plurality of first alignment marks and a plurality of second alignment marks can improve the alignment accuracy of the first alignment marks and the second alignment marks, and when part of the first alignment marks or the second alignment marks are unclear, other alignment marks 11 can be used for alignment, which has high reliability.

[0097] It should be noted that the alignment mark structure 1 and the alignment method of the substrate and the mask provided by the present invention can also be used to manufacture a substrate with a multi-layer circuit pattern. The following is an example of a product with two layers of circuit patterns. First, a substrate is provided, on which an alignment mark structure a (e.g. Figure 6 The alignment mark structure 1 shown in the figure provides a mask plate M1, and the mask plate M1 is provided with an alignment mark structure b (for example Figure 7 The alignment mark structure 1 shown is used. The alignment mark structure a is aligned with the alignment mark structure b by using the alignment method provided by the present invention, so that the substrate and the mask plate M1 are aligned, and the circuit pattern on the mask plate M1 is transferred to the substrate to form a first layer of circuit pattern; then, an insulating layer P1 is coated on the substrate, and the alignment mark structure a on the substrate is transferred to the insulating layer P1 by using the back exposure technology to form an alignment mark structure c with the same size and relative position as the alignment mark structure a, and a mask plate M2 is provided. The mask plate M2 is provided with an alignment mark structure d, and the alignment mark structure c is aligned with the alignment mark structure d by using the alignment method provided by the present invention, so that the substrate and the mask plate M2 are aligned, and the circuit pattern on the mask plate M2 is transferred to the substrate to form a second layer of circuit pattern; finally, an insulating layer P2 is formed on the substrate. Among them, the production of the circuit pattern includes the processes of coating, gluing, exposure, development, etching, demoulding, etc., and the production of the insulating layer includes the processes of gluing, exposure, development, etc. This part of the process is the same as the prior art and will not be repeated here. In the above-mentioned production process, by improving the alignment mark structure, adopting back exposure technology to form the alignment mark structure 1 on the middle layer (i.e., the insulating layer P1), and using the middle layer to assist in alignment, the alignment accuracy of each alignment can be effectively improved, thereby improving the position accuracy of the multi-layer circuit graphics and ensuring the substrate product yield.

[0098] In summary, in the alignment mark structure 1, substrate, mask plate, and alignment method of substrate and mask plate provided by the present invention, by improving the alignment mark structure 1, as well as the light source parameters of the image sensor during the alignment process, the negative influence of the opaque film layer of the substrate can be effectively eliminated, so that during the alignment process, the image sensor can recognize a clearer image of the alignment mark 11 and obtain the accurate position information of the alignment mark 11, thereby improving the alignment accuracy and ensuring the position accuracy between the substrate and the mask plate, thereby improving the substrate product yield.

[0099] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for aligning a substrate and a mask plate, characterized in that: The alignment method comprises: Providing a substrate, on which a first alignment mark and a first light-transmitting hole are provided, and on which an opaque film layer covering the first alignment mark and the first light-transmitting hole is further provided; Providing an auxiliary alignment film layer, wherein the auxiliary alignment film layer is disposed above the opaque film layer; Using a back exposure technique, forming an auxiliary alignment mark and an auxiliary light-transmitting hole having the same structure and position as the first alignment mark and the first light-transmitting hole on the auxiliary alignment film layer; Providing a mask plate, wherein a second alignment mark is provided on the mask plate; adjusting light source parameters of the image sensor according to the reflectivity of the opaque film layer; The image sensor is used to obtain the position coordinates of the auxiliary alignment mark to obtain the position information of the substrate, and the mask is adjusted according to the position information of the substrate to make the second alignment mark face the auxiliary alignment mark, and further make the second alignment mark face the first alignment mark.

2. The method for aligning a substrate and a mask according to claim 1, characterized in that: Adjusting the light source parameters of the image sensor according to the reflectivity of the opaque film layer includes: If the reflectivity of the opaque film layer is greater than 50%, adjusting the light source parameters of the image sensor includes: adjusting the light source brightness of the image sensor to 25%-35% of the maximum brightness; If the reflectivity of the opaque film layer is 30%-50%, adjusting the light source parameters of the image sensor includes: adjusting the light source brightness of the image sensor to 55%-65% of the maximum brightness; If the reflectivity of the opaque film layer is less than 30%, adjusting the light source parameters of the image sensor includes: adjusting the brightness of the light source of the image sensor to 85%-95% of the maximum brightness.

3. The method for aligning a substrate and a mask according to claim 1, characterized in that: When providing the mask plate, if the reflectivity of the opaque film layer is greater than or equal to 30%, a second light-transmitting hole is opened on the second alignment mark of the mask plate.

4. The method for aligning a substrate and a mask according to any one of claims 1 to 3, characterized in that: A plurality of the first alignment marks are disposed on the substrate, a plurality of the second alignment marks are disposed on the mask plate, and the plurality of the first alignment marks correspond to the plurality of the second alignment marks in a one-to-one manner.

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