Alignment marks

Abstract

This provides a method for aligning and bonding panels. [Solution] A panel alignment and bonding method comprising the steps of: generating four alignment marks on each panel via a photomask, wherein the offset marks are all asymmetrical with respect to the first corner marks, second corner marks, and third corner marks; aligning and bonding the first panel and the second panel to form a two-layer panel, aligning the first corner mark of the first panel with the third corner mark of the second panel, and aligning the third corner mark of the first panel with the first corner mark of the second panel; and aligning and bonding the two-layer panel and the third panel to form a three-layer panel, aligning the second corner mark of the first panel with the second corner mark of the third panel, and aligning the offset marks of the first panel with the offset marks of the third panel.

Description

Technical Field

[0001] The present disclosure relates to a panel alignment and bonding method and an alignment mark, and particularly to a panel alignment and bonding method and an alignment mark through the same photomask.

Background Art

[0002] A color cholesteric liquid crystal display is composed of a plurality of single-color cholesteric liquid crystal panels stacked together. How to accurately bond the single-color cholesteric liquid crystal panels has become a rather important issue in the manufacturing process of color cholesteric liquid crystal displays.

[0003] Specifically, for panels of a smaller size, the glass substrate can be thinned to facilitate the bonding device to capture a clear image of the alignment mark. However, the panel with the thinned glass substrate has low strength and is easily damaged during handling and touching, so this method cannot be applied to medium and large-sized panels.

[0004] Also, when aligning and bonding medium and large-sized panels with non-thinned thickness, the alignment mark of the panel provided in the middle is likely to interfere with the clarity of the image captured by the camera of the bonding device for the alignment mark of the panel provided on the bottommost layer or the outermost layer. Therefore, in the prior art, in order to solve the above problems, the following two methods have emerged. For example, before bonding, the alignment mark of the panel provided in the middle is removed by laser or chemical agents, but this method is likely to cause problems such as accidentally damaging or contaminating the panel, or manufacturing the panel provided in the middle with an additional photomask to cancel the alignment mark, but this method requires additional investment in expensive photomasks.

[0005] Therefore, developing panel alignment and bonding methods and alignment marks that do not require additional processing to achieve precise panel alignment and bonding, and that avoid contamination and damage to the panels, has become an important and urgent problem to solve in the industry. [Overview of the project] [Problems that the invention aims to solve]

[0006] This disclosure provides a panel alignment and bonding method and alignment marks that achieve the effect of manufacturing multiple panels from the same photomask and accurately aligning and bonding them by making one side of the alignment marks asymmetrical with the other three sides, and that improve the accuracy of panel alignment and bonding by providing a first region and a second region in the alignment marks. [Means for solving the problem]

[0007] According to one embodiment of the present disclosure, four alignment marks are generated on each of a plurality of panels via a photomask, the panels comprising a first panel, a second panel, and a third panel, and each of the alignment marks is located at one of the four corners of each panel and is a first corner mark, a second corner mark, a third corner mark, and an offset mark, the first corner mark and the second corner mark are symmetrical, the second corner mark and the third corner mark are symmetrical, and the offset mark is asymmetrical with respect to the first corner mark, the second corner mark, and the third corner mark, and the first panel and the second panel are aligned and bonded together to form a two-layer panel. The present invention provides a panel alignment and bonding method that includes the steps of forming a two-layer panel, rotating the second panel 180 degrees relative to the first panel, aligning the first corner mark of the first panel with the third corner mark of the second panel, aligning the third corner mark of the first panel with the first corner mark of the second panel, bonding them together, and forming a three-layer panel, aligning the two-layer panel and the third panel and bonding them together to form a three-layer panel, aligning the second corner mark of the first panel with the second corner mark of the third panel, aligning the offset mark of the first panel with the offset mark of the third panel, bonding them together, and forming a three-layer panel.

[0008] In the panel alignment and bonding method according to the embodiment described above, if alignment marks are generated on each panel via a photomask, the panel may further include a fourth panel.

[0009] The panel alignment and bonding method according to the embodiment described in the preceding paragraph may further include the steps of aligning and bonding the 3-layer panel and the 4th panel to form a 4-layer panel, rotating the 4th panel 180 degrees relative to the 1st and 3rd panels, aligning the offset mark of the 2nd panel with the offset mark of the 4th panel, aligning the 2nd corner mark of the 2nd panel with the 2nd corner mark of the 4th panel, and forming the 4-layer panel after bonding.

[0010] In the panel alignment and bonding method according to the embodiment described above, when aligning and bonding the first panel and the second panel to form a two-layer panel, when aligning and bonding the two-layer panel and the third panel to form a three-layer panel, and when aligning and bonding the three-layer panel and the fourth panel to form a four-layer panel, at least two cameras may be used for filming, and the cameras may be simultaneously provided above or below the two-layer panel, the three-layer panel, and the four-layer panel.

[0011] In the panel alignment and bonding method according to the embodiment described in the preceding paragraph, there may be four cameras, two of which are provided above the 2-layer panel, 3-layer panel, and 4-layer panel, while the other two cameras are provided below the 2-layer panel, 3-layer panel, and 4-layer panel.

[0012] In the panel alignment and bonding method according to the embodiment described above, the first panel, second panel, third panel, and fourth panel may each be a cholesterol liquid crystal panel.

[0013] In the panel alignment and bonding method according to the embodiment described above, the first panel, second panel, third panel, and fourth panel may be panels of different colors.

[0014] In the panel alignment and bonding method according to the embodiment described above, each of the first panel, second panel, third panel, and fourth panel may include a display area, and each of the alignment marks is located in an area other than the display area.

[0015] According to one embodiment of the present disclosure, an alignment mark provided on a panel includes a first region surrounded by a plurality of edges and at least one second region located within the first region, wherein the second region allows light rays to pass through, while other regions of the first region other than the second region prevent light rays from passing through, and the distance between the second region and one edge in the first region is 0.02 mm or less.

[0016] In the alignment marks according to the embodiment described in the preceding paragraph, the material of the first region may be metal.

[0017] In the alignment marks according to the embodiment described above, the second region may consist of five regions, each located at one of the four corners and the other at the center of the alignment marks.

[0018] In the alignment marks according to the embodiment described above, the shape of the first region may be cross-shaped, but the shape of the second region may be circular.

[0019] In the alignment marks according to the embodiment described above, the diameter of the second region may be less than 0.18 mm.

[0020] In the alignment marks according to the embodiment described above, the edge length may be 0.18 mm or less. [Brief explanation of the drawing]

[0021] [Figure 1] This is a flowchart of a panel alignment and bonding method according to one embodiment of the present disclosure. [Figure 2] Figure 1 is a schematic diagram of the photomask according to the embodiment. [Figure 3] This is a schematic diagram of the first panel according to the embodiment shown in Figure 1. [Figure 4] This is a schematic diagram of the second panel according to the embodiment shown in Figure 1. [Figure 5] This is a schematic diagram of the third panel according to the embodiment shown in Figure 1. [Figure 6] It is a schematic diagram of the fourth panel according to the embodiment of FIG. 1. [Figure 7] It is a schematic diagram of aligning and bonding the first panel and the second panel according to the embodiment of FIG. 1. [Figure 8] It is a schematic diagram of aligning and bonding the two-layer panel and the third panel according to the embodiment of FIG. 1. [Figure 9] It is a schematic diagram of aligning and bonding the three-layer panel and the fourth panel according to the embodiment of FIG. 1. [Figure 10] It is a schematic diagram of the alignment mark according to the embodiment of FIG. 1. **[Embodiment for Carrying out the Invention]**

[0022] Please refer to FIG. 1, which is a flowchart of the method for aligning and bonding panels according to an embodiment of the present disclosure. As can be seen from FIG. 1, the method S100 for aligning and bonding panels includes steps S101, S102, and S103.

[0023] Please refer to FIGS. 2 to 5. FIG. 2 is a schematic diagram of a photomask according to the embodiment of FIG. 1, FIG. 3 is a schematic diagram of the first panel according to the embodiment of FIG. 1, FIG. 4 is a schematic diagram of the second panel according to the embodiment of FIG. 1, and FIG. 5 is a schematic diagram of the third panel according to the embodiment of FIG. 1. As can be seen from FIGS. 1 to 5, in step S101, four alignment marks are generated on each of the plurality of panels through the photomask 110. The panels include the first panel 121, the second panel 122, and the third panel 123. Each of the alignment marks is located at the four corners of each panel (i.e., the first panel 121, the second panel 122, and the third panel 123), and each of the alignment marks includes a first corner mark 131, a second corner mark 132, a third corner mark 133, and an offset mark 134.

[0024] Furthermore, the first corner mark 131 and the second corner mark 132 are symmetrical, the second corner mark 132 and the third corner mark 133 are symmetrical, and the offset mark 134 is asymmetrical with respect to the first corner mark 131, the second corner mark 132, and the third corner mark 133. In other words, the offset mark 134 is offset from its original position, which is symmetrical to the first corner mark 131 and the third corner mark 133.

[0025] Refer to Figure 6, which is a schematic diagram of the fourth panel according to the embodiment of Figure 1. As can be seen from Figure 6, the panel may further include a fourth panel 124, where the first corner mark 131, the second corner mark 132, the third corner mark 133, and the offset mark 134 are located at the four corners of the fourth panel 124, respectively. Furthermore, each of the first panel 121, second panel 122, third panel 123, and fourth panel 124 may be a cholesterol liquid crystal panel, and the first panel 121, second panel 122, third panel 123, and fourth panel 124 may be panels of different colors, the first panel 121 may be a blue cholesterol liquid crystal panel, the second panel 122 may be a green cholesterol liquid crystal panel, the third panel 123 may be a red cholesterol liquid crystal panel, and the fourth panel 124 may be a black cholesterol liquid crystal panel. In Figures 3 to 6, B, G, R, and K are used to represent blue, green, red, and black, respectively, but are not limited to these. Also, each of the first panel 121, second panel 122, third panel 123, and fourth panel 124 may be formed by a photolithography process.

[0026] As can be seen from Figure 2, multiple marks 111, 112, 113, and 114 are provided on the photomask 110, and mark 114 is asymmetrical to marks 111, 112, and 113. Each of the individual positions of marks 111, 112, 113, and 114 corresponds to the individual positions of the first corner mark 131, the second corner mark 132, the third corner mark 133, and the offset mark 134 of the first panel 121, the second panel 122, the third panel 123, and the fourth panel 124.

[0027] As can be seen from Figures 3 to 6, each of the first panel 121, second panel 122, third panel 123, and fourth panel 124 may include a display area 135, and each of the alignment marks (i.e., the first corner mark 131, the second corner mark 132, the third corner mark 133, and the offset mark 134) is located in an area other than the display area 135.

[0028] Please refer to Figure 7, which is a schematic diagram of aligning and bonding the first panel and the second panel according to the embodiment in Figure 1. As can be seen from Figures 1 and 7, step S102 includes aligning and bonding the first panel 121 and the second panel 122 to form a two-layer panel, rotating the second panel 122 180 degrees relative to the first panel 121, aligning the first corner mark 131 of the first panel 121 with the third corner mark 133 of the second panel 122, aligning the third corner mark 133 of the first panel 121 with the first corner mark 131 of the second panel 122, and then bonding them to form a two-layer panel.

[0029] Please refer to Figure 8, which is a schematic diagram of aligning and bonding the two-layer panel and the third panel according to the embodiment in Figure 1. As can be seen from Figures 1 and 8, step S103 includes aligning and bonding the two-layer panel and the third panel 123 to form a three-layer panel, aligning the second corner mark 132 of the first panel 121 with the second corner mark 132 of the third panel 123, aligning the offset mark 134 of the first panel 121 with the offset mark 134 of the third panel 123, and forming the three-layer panel after bonding. Note that the offset mark 134 of the second panel 122 does not affect or interfere with the alignment of the second corner mark 132 of the first panel 121 with the second corner mark 132 of the third panel 123, and the second corner mark 132 of the second panel 122 does not affect or interfere with the alignment of the offset mark 134 of the first panel 121 with the offset mark 134 of the third panel 123.

[0030] Please refer to Figure 9, which is a schematic diagram of aligning and bonding the three-layer panel and the fourth panel according to the embodiment of Figure 1. As can be seen from Figures 1 and 9, the panel alignment and bonding method S100 may further include step S104, which involves aligning and bonding the three-layer panel and the fourth panel 124 to form a four-layer panel, rotating the fourth panel 124 180 degrees relative to the first panel 121 and the third panel 123, aligning the offset mark 134 of the second panel 122 with the offset mark 134 of the fourth panel 124, aligning the second corner mark 132 of the second panel 122 with the second corner mark 132 of the fourth panel 124, and forming the four-layer panel after bonding. Furthermore, the second corner mark 132 of the first panel 121 and the second corner mark 132 of the third panel 123 do not affect or interfere with the alignment of the offset mark 134 of the second panel 122 and the offset mark 134 of the fourth panel 124, and the offset mark 134 of the first panel 121 and the offset mark 134 of the third panel 123 do not affect or interfere with the alignment of the second corner mark 132 of the second panel 122 and the second corner mark 132 of the fourth panel 124.

[0031] As can be seen from Figures 7 to 9, when a two-layer panel is formed by aligning and bonding the first panel 121 and the second panel 122, when a three-layer panel is formed by aligning and bonding the two-layer panel and the third panel 123, and when a four-layer panel is formed by aligning and bonding the three-layer panel and the fourth panel 124, at least two cameras 140 can capture images, and the cameras 140 are simultaneously positioned above or below the two-layer, three-layer, and four-layer panels. Furthermore, there may be four cameras 140, two of which are positioned above the two-layer, three-layer, and four-layer panels, and the other two are positioned below the two-layer, three-layer, and four-layer panels. The number of cameras 140 is determined by the requirements of the process, but is not limited thereto.

[0032] Furthermore, the bonding order of the first panel 121, second panel 122, third panel 123, and fourth panel 124 may be from top to bottom or bottom to top, and the first panel 121, second panel 122, third panel 123, and fourth panel 124 may each have a thickness of 0.2 mm to 0.5 mm and an area of ​​13.3 inches to 27.6 inches, but are not limited thereto.

[0033] In Figures 7 to 9, the offset mark 134 is shown in an X-shape and its offset position is emphasized to prevent interference during alignment and bonding, and to avoid interference with other alignment marks. The actual offset mark 134 and the first corner mark 131, second corner mark 132, and third corner mark 133 are similarly cross-shaped on the panel, as shown in Figures 3 to 6. Furthermore, the offset mark 134 may have a shape different from the X-shape or the first corner mark 131, second corner mark 132, and third corner mark 133 in Figures 7 to 9, thereby achieving the effect of preventing interference during alignment and to avoid interference with other alignment marks.

[0034] Please refer to Figure 10, which is a schematic diagram of the alignment mark according to the embodiment in Figure 1. As can be seen from Figure 10, the alignment mark (not shown) includes a first region 151 surrounded by a plurality of edges 153, and a plurality of second regions 152 located within the first region 151. The second regions 152 allow light rays to pass through, while the other regions of the first region 151, excluding the second regions 152, prevent light rays from passing through. The distance DS between the second region 152 and the edges 153 in the first region 151 is 0.02 mm or less, and may be between 0.01 mm and 0.02 mm. The alignment mark is provided on the panel. Specifically, it is possible to avoid the alignment mark completely blocking the passage of the coaxial light source via the second region 152.

[0035] The alignment marks in Figure 10 may also be the first corner marks 131, 2 corner marks 132, 3 corner marks 133 and offset marks 134 on the first panel 121, second panel 122, third panel 123 and fourth panel 124, and marks 111, 112, 113 and 114 provided on the photomask 110.

[0036] The material of the first region 151 may be metal, the length PD of the edge 153 may be 0.18 mm or less, the number of edges 153 in the first region 151 may be multiple, and the length of each edge 153 may be the same. Specifically, the above values ​​are determined by the capabilities of the exposure, development, and etching processes of the photolithography process, and are also related to the lens magnification and field of view provided by the camera 140.

[0037] The second region 152 may consist of five regions, each of which is located at one of the four corners and the center of the alignment marks. The shape of the first region 151 may be cross-shaped, while the shape of the second region 152 may be circular. The diameter DA of the second region 152 may be less than 0.18 mm, but is not limited to the above number and shape.

[0038] In detail, the distance DS between the second region 152 and the edge 153 of the first region 151 in Figure 10 is 0.015 mm, the diameter DA of the second region 152 is 0.15 mm, and the length PD of the edge 153 is 0.18 mm.

[0039] As described above, the panel alignment and bonding method of this disclosure enables the formation of four panels via the same photomask and achieves precise alignment. The alignment marks on the diagonals of each panel do not cause interference problems during alignment. Furthermore, the panel alignment and bonding method can be applied to panels of different areas. This saves process and costs, and also solves the problem of damage or contamination of panels by the photomask. In addition, the alignment marks of this disclosure further enhance the alignment effect, allowing the camera to receive clearer images of the alignment marks during alignment and bonding, thereby increasing the accuracy of panel alignment and bonding.

[0040] Although the present invention is disclosed as described above in the examples, these examples are not intended to limit the present invention, and any person skilled in the art can make several modifications and alterations without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the subsequent appended patent application. [Explanation of symbols]

[0041] S100: Panel alignment and bonding method S101, S102, S103, S104: Process 110: Photomask 111,112,113,114: Mark 121: Panel 1 122: Panel 2 123: Panel 3 124: Panel 4 131: First corner mark 132: Second corner mark 133: Third corner mark 134: Offset Mark 135:Display area 140: Camera 151:First area 152:Second area 153: Edge DA: Diameter of the second region DS: Distance between the edge of the second region and the first region. PD: Edge length

Claims

1. Alignment marks provided on the panel, The first region is enclosed by multiple edges, At least one second region located within the first region, Includes, The at least one second region allows light rays to pass through, while the other regions of the first region, other than the at least one second region, prevent light rays from passing through. Alignment marks wherein the distance between at least one second region and one edge in the first region is 0.02 mm or less.

2. The alignment mark according to claim 1, wherein the material of the first region is metal.

3. The alignment mark according to claim 1, wherein the at least one second region is five in number, each located at one of the four corners and the center of the alignment mark.

4. The alignment mark according to claim 1, wherein the shape of the first region is cross-shaped, and the shape of at least one second region is circular.

5. The alignment mark according to claim 4, wherein the diameter of at least one second region is less than 0.18 mm.

6. The alignment mark according to claim 1, wherein the length of the edge is 0.18 mm or less.

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