Multiple photomask alignment apparatus and alignment method for manufacturing fine metal mask for large area display

Abstract

The present invention relates to a plurality of photomask alignment apparatuses and alignment methods for manufacturing a fine metal mask for a large-area display, and more particularly to a plurality of photomask alignment apparatuses for manufacturing a fine metal mask for a large-area display, characterized by comprising: a photomask mounting bracket; a photomask suction part formed on an edge of the photomask mounting bracket; an alignment reference part formed with at least two alignment reference points located at positions overlapping alignment marks; and a camera device mounted at a position capable of photographing an overlapping state of the alignment reference part and alignment marks, at least one of the alignment reference points overlapping alignment marks formed on a first photomask among a plurality of photomasks, and the remaining alignment reference points overlapping alignment marks formed on a second photomask aligned adjacent to the first photomask.

Description

Technical Field

[0001] This invention relates to a multiple photomask alignment apparatus for manufacturing fine metal masks for large-area displays. More specifically, to facilitate the manufacture of fine metal masks for 8th-generation large-area displays, multiple photomask raw materials or multiple photomasks are used in combination, thereby enabling the manufacture of 8th-generation fine metal masks with extended effective portions. Therefore, compared to fine metal masks for manufacturing 6.5th-generation displays, manufacturing fine metal masks with extended effective portions not only improves production efficiency but also allows for the utilization of existing exposure apparatuses used for manufacturing 6.5th-generation fine metal masks. Background Technology

[0002] In the development of the display industry, "larger size" has become the foundation for creating new markets and expanding scale for sustained growth. Larger size refers to the construction of large-area display panel production lines and the increase in the size of the panels produced. Display manufacturers have made considerable efforts to build large-area production lines, improve productivity, and manufacture larger panels at lower costs.

[0003] Fine metal masks, as a core component for depositing OLED elements on display panels, are no longer sufficient to keep up with the trend of larger display panels, as the existing fine metal masks used for depositing 6.5-generation OLED pixels are struggling to keep pace with the trend of larger display areas. Therefore, there is now a need to develop fine metal masks for depositing 8th-generation OLED pixels (hereinafter referred to as "8th-generation masks").

[0004] The fine metal mask includes: an effective portion, which serves as a patterned area for depositing pixels; and a clamping portion, formed at both ends of the effective portion, to serve as a mask fixing function during pixel deposition for placing the fine metal mask on a plate.

[0005] However, the effective length of the 6.5 generation mask is 1100 mm, while the effective length of the 8th generation mask is 2200 mm, which is 2600 mm including the length of the clamping part. Therefore, it is difficult to manufacture the 8th generation mask using existing exposure machines that can expose up to 2400 mm.

[0006] In addition, a large amount of capital is required to manufacture exposure machines suitable for producing 8th generation masks, which is expected to result in correspondingly high market prices. This also raises the issue of increasing the burden by introducing new exposure machines.

[0007] Furthermore, photomasks used to manufacture 8th generation masks are often laminated in pairs or more. During the lamination of two pre-processed photomasks, there is a high possibility that the continuity or consistency of alignment between the two photomasks cannot be guaranteed. As mentioned above, if the continuity or consistency of alignment cannot be guaranteed, pixel defects may occur during pixel formation, potentially leading to a decrease in display resolution. Therefore, the development of new engineering techniques for manufacturing 8th generation masks is anticipated. Summary of the Invention

[0008] Technical issues

[0009] This invention addresses the problems of the prior art described above. The purpose of this invention is to manufacture a fine metal mask with high alignment accuracy for the manufacture of 8th generation large-area displays by aligning multiple photomasks with high precision.

[0010] Another objective of this invention is to provide a new photomask alignment device and method that utilizes existing exposure machines, thereby eliminating the need to develop new exposure machines and maximizing the utilization of conventional exposure machines when manufacturing fine metal masks for 8th generation large-area displays.

[0011] Another object of the present invention is to enable the manufacture of independent aligners for aligning multiple photomasks, and to enable the precise alignment of multiple photomasks by a simple method.

[0012] In addition, another object of the present invention is to maintain the alignment state when transferring multiple aligned photomasks to the exposure machine, by strengthening the second photomask adsorption port on the photomask bonding frame, so that the photomasks are transferred to the exposure machine in the adsorption state for exposure, thereby enabling the manufacture of a precision 8th generation fine metal mask.

[0013] Technical solutions

[0014] To achieve the above objectives, a plurality of photomask alignment apparatus for manufacturing fine metal masks for large-area displays is provided, characterized in that it comprises: a photomask mounting bracket; a photomask adsorption portion formed on the edge of the photomask mounting bracket; an alignment reference portion having at least two alignment reference points located at positions overlapping with alignment marks; and an imaging device mounted at a position capable of capturing the overlap state of the alignment reference portion and the alignment marks, wherein at least one of the alignment reference points overlaps with an alignment mark formed on a first photomask of the plurality of photomasks, and the remaining alignment reference points overlap with an alignment mark formed on a second photomask, the second photomask being aligned adjacent to the first photomask.

[0015] The photomask alignment device preferably includes: a photomask lifting rod, which is movably disposed at the lower part of the photomask mounting bracket; and a support glass, which is located on the boundary surface during the lamination of the plurality of photomasks and is used to support the photomasks.

[0016] Preferably, the number of the camera devices is the same as the number of the alignment reference points.

[0017] Preferably, it also includes a bonding frame for supporting the photomask from the top, wherein at least a portion of the surface of the bonding frame in contact with the photomask is formed with a second mask adsorption portion.

[0018] Furthermore, the present invention provides a method for aligning multiple photomasks for manufacturing fine metal masks for large-area displays, characterized in that the method is performed by the alignment device and includes: a first step of forming at least one alignment mark on a photomask; a second step of aligning at least two photomasks with the alignment mark formed thereon once and mounting them on a photomask mounting bracket of an exposure machine; a third step of confirming the position of the alignment mark between the mounted photomasks; and a fourth step of determining whether the alignment state is complete based on the confirmed position of the alignment mark, wherein the completion of the alignment state is determined by whether the alignment mark formed on each photomask is consistent with the alignment reference portion, and if the alignment state is not complete, the photomasks are aligned a second time, and then the process begins again from the third step.

[0019] The effects of the invention

[0020] According to the present invention as described above, the following effect is expected: high alignment accuracy is achieved by aligning multiple photomasks with high precision.

[0021] In addition, the present invention is expected to provide a new photomask alignment device and method that utilizes existing exposure machines, thereby eliminating the need to develop new exposure machines and maximizing the utilization of general exposure machines when manufacturing fine metal masks for 8th generation large-area displays.

[0022] In addition, the present invention anticipates the following effect: by manufacturing independent aligners for aligning multiple photomasks, multiple photomasks can be precisely aligned by a simple method before performing the exposure process.

[0023] In addition, the present invention anticipates the following effect: in order to maintain the alignment state when transferring multiple aligned photomasks to the exposure machine, the second photomask adsorption port is reinforced on the photomask bonding frame, so that the photomasks are transferred to the exposure machine in the adsorption state for exposure, thereby enabling the manufacture of a precise 8th generation fine metal mask. Attached Figure Description

[0024] Figure 1 As a flowchart illustrating the process of laminating two separate photomasks according to an embodiment of the present invention and ensuring alignment, the case of using independent alignment devices is shown.

[0025] Figure 2 To show from the side Figure 1 The alignment device is shown along with the process of lamination and alignment status confirmation for the photomask.

[0026] Figure 3 A diagram showing a second photomask adsorption portion formed on a photomask bonding frame according to an embodiment of the present invention is provided together with the exposure machine mounting frame. Detailed Implementation

[0027] Hereinafter, to facilitate implementation by those skilled in the art, an embodiment of the invention will be described in more detail with reference to the accompanying drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Furthermore, irrelevant portions have been omitted in the drawings for clarity, and similar reference numerals are used for similar portions throughout the specification.

[0028] When a part of the specification "includes" a certain constituent element, it means that other constituent elements are not excluded, but may be included, unless otherwise stated.

[0029] In addition, the terms "...part" and "...machine" used in the instruction manual refer to a unit that processes at least one function or action.

[0030] This invention relates to the manufacture of an 8th generation fine metal mask, characterized in that its effective portion is twice as long as that of the existing 6.5th generation fine metal mask. The overall length of the 8th generation fine metal mask is 2600 mm, which is 1100 mm longer than the 1500 mm overall length of the 6.5th generation fine metal mask. Furthermore, the exposure machine is used to perform the exposure process as part of the manufacturing of the fine metal mask. Because it can expose a workpiece up to 2500 mm in length, it is possible to expose the entire 6.5th generation fine metal mask in one operation, but it is not possible to expose the entire 8th generation fine metal mask in one operation.

[0031] Figure 1 As a flowchart illustrating the process of laminating two separate photomasks according to an embodiment of the present invention and ensuring alignment, the case of using independent alignment devices is shown. Figure 2 To show from the side Figure 1The alignment device is shown along with the process of lamination and alignment status confirmation for the photomask. Figure 3 A diagram showing a second photomask adsorption portion formed on a photomask bonding frame according to an embodiment of the present invention is provided together with the exposure machine mounting frame.

[0032] It is important to note that Figure 1 The diagram shows the planar shape related to the adsorption portion 171 formed on the photomask mounting bracket 170 on which photomasks 130-1 and 130-2 are mounted. On the other hand, Figure 2 and Figure 3 The planar shape associated with the bonding frame 230 and the second photomask adsorption part 231 is shown.

[0033] Figure 1 and Figure 2 A photomask mounting bracket 170, constructed independently of the exposure machine, is shown, in which a photomask alignment device 200, including a lifting rod 173 and supporting glass, is provided.

[0034] like Figure 1 and Figure 2 As shown, the photomask alignment apparatus 200 according to this embodiment includes an alignment reference 181 and a camera device, has a fixed photomask alignment system 180, and is configured as an independent support structure including a photomask mounting bracket 170 capable of supporting the photomask.

[0035] That is, the photomask alignment device 200 includes: a photomask mounting bracket 170; a photomask adsorption portion 171 formed on the edge of the photomask mounting bracket 170; an alignment reference portion 181 having at least two alignment reference points 182, the alignment reference points 182 being located at positions overlapping with alignment marks 145; and an imaging device 183 mounted at a position capable of capturing the overlapping state of the alignment reference portion 181 and the alignment marks 145, wherein at least one of the alignment reference points 182 overlaps with the alignment mark 145 formed on a first photomask among a plurality of photomasks, and the remaining alignment reference points overlap with the alignment mark 145 formed on a second photomask, the second photomask being aligned adjacent to the first photomask.

[0036] The photomask mounting bracket 170 and photomask adsorption part 171 of this embodiment have the following structure: 1) They are constructed separately from the structure formed on the exposure machine; 2) A photomask alignment system 180, including an alignment reference part 181 and an imaging device 183, is fixed on the bracket; 3) Legs are formed on the lower part of the bracket; 4) A photomask lifting rod 173 is provided at the lower part of the photomask mounting bracket 170 so that it can be raised and lowered in the central part surrounded by the bracket and performs the function of supporting the photomask and placing it on the bracket.

[0037] It also includes a support 220, which, when the alignment state is determined after laminating the plurality of photomasks, is located on the boundary surface of the photomasks and supports them, and can maintain their alignment state when the photomasks move. The material of the support 220 is not limited, but glass is preferred.

[0038] Figure 1 In the photomask mounting bracket 170 shown in the figure, the central portion surrounded by the bracket is through which the photomask is supported (mounted), and the transparent support plate 172 on which the photomask is placed is located in the central portion.

[0039] The support plate 172 is primarily made of glass. This is because glass is heat-resistant and transparent, making it suitable for performing the exposure process. However, suitable materials other than glass can be used as alternative materials.

[0040] Furthermore, a slit 171 for applying negative pressure is provided on the edge of the support 170. When supporting the photomask, the negative pressure allows the photomask 130 to be placed on the support, thereby achieving a stable fixation of the photomask 130. The slit 171 can be replaced by a hole, and the gap space that can utilize the negative pressure can be of any shape.

[0041] The photomask mounting bracket 170 has dimensions capable of supporting two unit photomasks 130-1 and 130-2 that can be manufactured. However, the number of photomasks that can be supported is not limited to two, and more photomasks can be supported depending on the size of the bracket or the length of the photomask.

[0042] The photomask mounting bracket 170 can hold a single photomask and, using it, can be used in the process of exposing the metal sheet 190 to laminate and support multiple photomasks 130-1 and 130-2, and can also confirm their alignment. When laminating multiple photomasks, precise pattern alignment is required; therefore, precise alignment of multiple photomasks is necessary, and additional means to confirm the alignment status are needed.

[0043] In response, the present invention provides an alignment device equipped with a photomask alignment system 180, which can accurately confirm the alignment state of the laminated photomask and realize a laminated photomask with an alignment state suitable for performing an exposure process.

[0044] More specifically, the process of manufacturing the photomask includes: a first step of forming at least one alignment mark 145 on the photomask; a second step of aligning at least two photomasks with the alignment mark 145 formed thereon once and mounting them on the photomask mounting bracket 170 of the exposure machine; a third step of confirming the position of the alignment mark 145 between the mounted photomasks; and a fourth step of determining whether the alignment state is complete based on the confirmed position of the alignment mark 145, and if the alignment state is not complete, aligning the photomask a second time and starting from the third step again.

[0045] The alignment mark 145 formed on the photomask is preferably located away from the area where the pattern is formed. Therefore, it is preferable to set it in the adjacent area of ​​the photomask vertices at the four corners as the most reliable location.

[0046] The alignment marks 145 can be all located at the four vertices, or preferably formed at least at both ends of the long side. That is, the alignment marks 145 are most preferably marked at positions suitable for confirming the alignment status of the unit photomask and adjacent unit photomasks.

[0047] Alignment marks 145 are formed on the same coordinates of photomasks of the same alignment target, thereby enabling the regularization of alignment state confirmation. After confirming the alignment state between photomasks, the alignment state is determined accordingly to connect to the next exposure process. If it is determined that the alignment state is not yet complete, the alignment state is reconfirmed by re-aligning. The confirmation of the alignment state can be continuously performed until the alignment state is determined. Whether the alignment state is complete or not can be determined based on whether the alignment marks formed on each photomask are consistent with the alignment reference area.

[0048] The alignment status can be confirmed by a photomask alignment system 180. This system includes: an alignment reference section 181 having at least two alignment reference points 182 located at positions overlapping with alignment marks 145; and an imaging device 183 mounted at a position capable of capturing images of the overlap between the alignment reference section 181 and the alignment marks 145. However, at least one of the alignment reference points 182 overlaps with an alignment mark 145 formed on a first photomask among a plurality of photomasks, and the remaining alignment reference point overlaps with an alignment mark 145 formed on a second photomask, the second photomask being aligned adjacent to the first photomask.

[0049] The illustration shows an alignment mark 145 formed on each of the adjacent vertex regions of the first and second photomasks. However, as mentioned above, the number of alignment marks 145 is not particularly limited as long as alignment confirmation can be performed accurately.

[0050] The alignment reference portion 181 can be made of a transparent material. For example, the transparent reference portion is made semi-transparent, thereby reducing the effect of light reflection during imaging. As a result, the overlap between the alignment reference point 182 and the alignment mark 145 can be confirmed with the naked eye. Moreover, the alignment mark 145 is formed on the upper or lower surface of the photomask, and obviously, the surface on which the alignment mark 145 is formed is not limited to a certain surface.

[0051] The photomask alignment device 180 can be located at the upper or lower part of the photomask. That is, since the support portion supporting the photomask is transparent glass, the alignment status can also be confirmed from the lower part of the photomask.

[0052] The photomask is preferably supported at a reference position on the support 170, thereby enabling the alignment system 180 to confirm the alignment status of the photomask. As described above, it is necessary to set reference points for the support position of the photomask and the alignment measurement position of the alignment system 180 in order to easily and accurately confirm and determine the alignment status of the photomask 130 in a short time.

[0053] The alignment status is confirmed by the camera device 183. The alignment status captured by the camera device 183 is transmitted to the control unit (not shown) via wireless communication. After confirming the alignment status, the control unit decides whether the alignment status is confirmed. If the confirmation result of the alignment status indicates that realignment is necessary, it is transmitted again to the alignment device to execute the corresponding process.

[0054] Furthermore, the camera device 183 preferably has the same number as the alignment reference points 182, but it is also obviously possible to confirm the alignment status by moving a movable camera device 183.

[0055] Figure 2 To show from the side Figure 1 The alignment device is shown along with the process of lamination and alignment status confirmation for the photomask. Figure 3 A diagram showing a second photomask adsorption portion formed on a photomask bonding frame according to an embodiment of the present invention is provided together with the exposure machine mounting frame.

[0056] In this invention, two photomasks 130-1 and 130-2 are fixed on a bonding frame 230. A second photomask adsorption part 231 is constructed on the bonding frame 230, thereby providing a strong adsorption and fixation function for the photomasks 130-1 and 130-2 during the process of moving them to the exposure machine. The bonding frame 230 is mounted on the exposure machine mounting bracket 240 to perform the exposure process. That is, as... Figure 3As shown, a fine metal mask can be manufactured by exposing a metal sheet as a component, consisting of a photomask 130, a bonding frame 230, and an exposure machine mounting bracket 240. Since the manufacturing process of a fine metal mask is known technology, a detailed description is omitted.

[0057] One feature of the present invention is that, according to the second photomask adsorption portion 231 constructed on the bonding frame 230, a plurality of photomasks 130 are able to maintain their originally determined alignment state.

[0058] It should be noted that the above embodiments are for illustrative purposes only and not for limiting the present invention. Furthermore, those skilled in the art should understand that various embodiments can be implemented within the scope of the present invention's concept.

Claims

1. A plurality of photomask alignment apparatus for manufacturing fine metal masks for large-area displays, characterized in that, include: Photomask mounting bracket; A photomask adsorption section is formed on the edge of the photomask mounting bracket; An alignment reference section is formed having at least two alignment reference points, which are located at positions overlapping with alignment marks; as well as The camera device is installed at a position capable of capturing the overlap between the alignment reference and the alignment mark. At least one of the alignment reference points overlaps with an alignment mark formed on a first photomask among a plurality of photomasks, and the remaining alignment reference points overlap with alignment marks formed on a second photomask, the second photomask being aligned adjacent to the first photomask. The plurality of photomask alignment devices also include: A photomask lifting rod is movably mounted on the lower part of the photomask mounting bracket; as well as Supporting glass, during the lamination of the multiple photomasks, supports the photomasks on the boundary surface. It also includes a bonding frame for supporting the photomask from above, wherein a second photomask adsorption portion is formed on at least a portion of the surface of the bonding frame that contacts the photomask, the supporting glass prevents sagging by supporting the bonding boundary surfaces of the plurality of photomasks, and the bonding frame and the second photomask adsorption portion maintain the relative positions of the plurality of photomasks when the aligned plurality of photomasks are transferred to the exposure machine.

2. The plurality of photomask alignment apparatus for manufacturing fine metal masks for large-area displays according to claim 1, characterized in that, The number of camera devices is the same as the number of alignment reference points.

3. A method for aligning multiple photomasks for manufacturing fine metal masks for large-area displays, performed by the alignment apparatus according to claim 1, characterized in that, include: The first step is to form at least one alignment mark on the photomask; The second step is to align at least two photomasks with the alignment marks formed on them at once and mount them on the photomask mounting bracket of the exposure machine. The third step is to confirm the position of the alignment marks between the installed photomasks; as well as The fourth step is to determine whether the alignment is complete based on the confirmed alignment marks. Whether the alignment state is completed is determined by whether the alignment marks formed on each photomask are consistent with the alignment reference. If the alignment state is not completed, the photomask is aligned a second time, and then the third step is started again.

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