Metal mask posture control device, posture control method, and program

Abstract

To suppress a deterioration in vapor deposition accuracy due to the deflection of a metal mask.SOLUTION: A posture control device for a metal mask includes: a marker information acquisition section that acquires marker information related to a marker provided on the metal mask; a posture information acquisition section that acquires posture information pre-associated with the metal mask; and a control section that controls the driving of a displacement section for displacing a frame section of the metal mask. The displacement control section controls the driving of the displacement section such that a posture of the metal mask based on the marker information and a posture of the metal mask based on the posture information satisfy a predetermined matching condition, on the basis of the marker information and the posture information.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present technology relates to a posture control device for a metal mask, a posture control method, and a program.

Background Art

[0002] Conventionally, for example, the vacuum evaporation method has been widely adopted for forming a film such as an organic EL light-emitting layer in an OLED (Organic Light Emitting Diode) device. In the vacuum evaporation process, for example, according to the opening pattern of a metal mask prepared for each color of red (R), green (G), and blue (B), light-emitting materials of each color are arranged and evaporated at predetermined positions on a substrate (coating separation method).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the manufacture of an organic EL display, with the increase in size and / or higher definition of the display, it is required to deposit a finer RGB pattern on a larger substrate. For example, on a substrate of the sixth generation (around 1500 mm × 1800 mm) or about half of its size (around 1500 mm × 900 mm), a fine pattern with a resolution of 600 to 1000 ppi or the like is deposited. This resolution is scaled up, for example, to 8.5G, and it is expected that an accuracy of several thousand ppi will be required in the future.

[0005] In this vapor deposition process, for example, considering the deflection of the metal mask, "vertical vapor deposition" in which the metal mask and the substrate are set upright for vapor deposition may be introduced. However, even in this vertical vapor deposition, it is required to further improve the vapor deposition accuracy. Furthermore, considering the size of the vapor deposition chamber and the handling property, for example, even for a large substrate, it is more desirable to be able to perform vapor deposition with high accuracy while keeping the metal mask and the substrate lying horizontally.

[0006] The present technology has been made in view of the above circumstances, and aims to suppress a decrease in vapor deposition accuracy due to the deflection of the metal mask.

Means for Solving the Problems

[0007] In the case of vapor deposition on a large substrate, the vapor deposition accuracy may decrease compared to vapor deposition on a smaller substrate, and this can occur not only in horizontal vapor deposition but also in vertical vapor deposition, although there is a difference in degree. The present inventors have found that this decrease in accuracy is largely due to a deviation between, for example, the appropriate posture of the metal mask and the posture during vapor deposition. The present technology has been made based on this finding.

[0008] (1) The posture control device for a metal mask according to the present technology includes a marker information acquisition unit that acquires marker information regarding a marker provided on the metal mask, a posture information acquisition unit that acquires posture information pre-associated with the metal mask, and a displacement control unit that controls the drive of a displacement unit for displacing a frame portion of the metal mask. The displacement control unit controls the drive of the displacement unit so that the posture of the metal mask based on the marker information and the posture of the metal mask based on the posture information satisfy a predetermined coincidence condition.

[0009] With such a configuration, it is possible to control the posture of the metal mask during vapor deposition based on predetermined posture information determined for each metal mask. Thereby, for example, the posture of the metal mask during vapor deposition in the vapor deposition process can be adjusted so that a desired mask pattern is realized. Thereby, for example, in horizontal vapor deposition, it is possible to suppress the deflection of the metal mask caused by variations in the flatness of the mounting surface of the stage and perform vapor deposition. Also, for example, in vertical vapor deposition, the metal mask can be controlled to a posture that can realize a desired mask pattern without being affected by the difference between the flatness of the metal mask and the flatness of the substrate. Subsequently, it is possible to suppress a decrease in vapor deposition accuracy due to the bending of the metal mask.

[0010] (2) In a preferred embodiment of the metal mask posture control device described in (1) above, the displacement control unit performs a first displacement operation to displace the frame portion of the metal mask by the displacement unit, and the marker information acquisition unit acquires first marker information regarding a marker provided on the metal mask on which the first displacement operation has been performed. The displacement control unit, based on the first marker information and the posture information, performs a second displacement operation to displace the frame portion of the metal mask by the displacement unit so that the posture of the metal mask based on the first marker information and the posture of the metal mask based on the posture information satisfy a predetermined coincidence condition.

[0011] (3) In a preferred embodiment of the metal mask posture control device described in (1) or (2) above, the displacement unit includes a first displacement unit that displaces at least one first position closer to the center than a predetermined reference in the frame portion, and a second displacement unit that displaces at least one second position farther from the center than a predetermined reference from the center of the frame portion. The displacement control unit displaces the second position by the second displacement unit after displacing the first position by the first displacement unit.

[0012] (4) In a preferred embodiment of the metal mask attitude control device according to (3) above, the metal mask is rectangular, the second position is at the four corners of the metal mask, the first position is located between the four corners of the metal mask, and the displacement control unit displaces at least one of the first positions between the four corners of the metal mask by the first displacement unit and then displaces at least one of the second positions at the four corners of the metal mask by the second displacement unit.

[0013] (5) In a preferred embodiment of the metal mask attitude control device according to any one of (1) to (4) above, the metal mask is a metal mask assembly including a mask sheet portion having openings of a predetermined pattern and a support frame portion supporting the mask sheet portion, and the attitude information is information regarding the attitude of the support frame portion at the time of manufacturing the metal mask assembly.

[0014] (6) In a preferred embodiment of the metal mask attitude control device according to any one of (1) to (5) above, the marker information is position information of a marker provided on the metal mask.

[0015] (7) In a preferred embodiment of the metal mask attitude control device according to any one of (1) to (6) above, the metal mask has a maximum dimension in a plan view of 1000 mm or more.

[0016] (8) In a preferred embodiment of the metal mask attitude control device according to any one of (1) to (7) above, the metal mask is a vapor deposition metal mask for manufacturing an organic EL display panel.

[0017] (9) In a preferred embodiment of the metal mask attitude control device according to any one of (1) to (8) above, the displacement unit is a pressing unit for pressing the frame portion of the metal mask, and the displacement control unit controls the pressing amount of the pressing unit.

[0018] (10) In a preferred embodiment of the metal mask attitude control device according to any one of (1) to (9) above, a storage unit storing a machine learning model learned based on machine learning that takes the marker information and the attitude information as inputs and outputs control information for the displacement unit is further provided, and the displacement control unit controls the driving of the displacement unit based on the control information output when the marker information and the attitude information are input to the machine learning model.

[0019] (11) From another aspect, the present technology provides a method for controlling the attitude of a metal mask, including the steps of acquiring information regarding a marker provided on the metal mask, acquiring attitude information pre-associated with the metal mask, and driving a displacement unit for displacing a frame portion of the metal mask. In the step of driving, based on the information regarding the marker of the metal mask and the attitude information regarding the metal mask, the frame portion of the metal mask is displaced by the displacement unit so that the attitude of the metal mask based on the information regarding the marker and the attitude of the metal mask based on the attitude information satisfy a predetermined coincidence condition. Thereby, the attitude of the metal mask during vapor deposition can be controlled based on predetermined attitude information determined for each metal mask.

[0020] (12) From yet another aspect, the present technology provides a program for causing a computer to execute each step of the method in (11) above.

Effect of the Invention

[0021] According to the technology described in the specification of the present application, it is possible to suppress a decrease in vapor deposition accuracy due to the deflection of the metal mask.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0023] <Embodiment 1> First, a metal mask assembly (also referred to as a fine metal mask assembly (FMMA), etc.) will be described. Figure 1 is a diagram for explaining the metal mask assembly 60. The metal mask assembly 60 is, for example, a metal vapor deposition mask used for vapor-depositing RGB light-emitting material layers or electrodes of an OLED display, and is composed of a metal mask sheet 61 having openings corresponding to a vapor deposition pattern and a metal frame portion 62 that supports this mask sheet. The mask sheet 61 is prepared, for example, for each RGB of each OLED display and is fixed to the frame portion 62 by means such as welding. The frame portion 62 is used over a long period by replacing different mask sheets 61 with the same opening pattern or different opening patterns.

[0024] In the vapor deposition process, an inspection process is provided to check whether the metal mask assembly 60 has deteriorated or been damaged and does not meet the specified criteria at a predetermined timing. In the inspection process, for example, the distortion and peeling of the openings of the mask sheet 61 are checked. If the metal mask assembly 60 has deteriorated or been damaged and does not meet the specified criteria, the mask sheet 61 is peeled off from the frame portion 62, and a new mask sheet 61 is welded to the frame portion 62 to regenerate the metal mask assembly 60.

[0025] In this metal mask assembly 60, alignment markers for precise alignment with the substrate 90 are provided, for example, near the center of the mask sheet 61 so that RGB can be painted separately at precise and accurate positions. The alignment markers are typically holes passing through the mask sheet 61. The metal mask assembly 60 in the present technology is provided with markers for posture confirmation on the frame portion 62. The markers for posture confirmation are provided, for example, at positions on the substrate-facing surface of the frame portion 62 that do not face the substrate during vapor deposition. The markers for posture confirmation may be, for example, through holes or imprints, and in this example, they are imprints recessed from the surface of the frame portion 62. Note that the markers for posture confirmation may be provided on the mask sheet 61 or on both.

[0026] The size of the metal mask targeted by the present technology is not particularly limited. However, for example, when targeting a metal mask with a shape and material that deflects due to its own weight when placed horizontally, the advantages of the present technology are clearly demonstrated, which is beneficial. Also, the metal mask may be one size larger than the glass substrate to be vapor-deposited in order to provide markers for posture confirmation or to secure displacement positions (here, pressing positions) for the later-described posture control. Such metal masks vary depending on the material and configuration, but the glass substrate size to be vapor-deposited can be based on, for example, the fourth generation (730 mm × 920 mm) or larger, the fifth generation (1100 mm × 1250 mm) or larger, 6G half (1500 mm × 900 mm) or larger, the sixth generation (1500 mm × 1800 mm or larger), 7G half (1800 mm × 1050 mm) or larger, etc.

[0027] According to the study by the present inventors, individual differences can occur in the metal members used for the metal mask due to, for example, differences in metal structure and usage history. FIG. 1 shows the results of measuring the vertical position of the frame surface of the frame portion 62 of the same standard (for example, 6G half) placed on a certain stone surface plate used in the inspection process. The stone surface plate is an element that provides a reference plane in assembly and inspection that requires an absolute plane. The left side of the figure shows the measurement positions P1 to P16 in the frame portion 62, and the right side shows the measurement results of the vertical position of the frame surface with respect to the stone surface plate as relative values based on the measurement position P1 in the upper left. The relatively large frame portion 62 bends along the stone surface plate due to its own weight, but the surface of the frame portion 62 after bending is not a strict horizontal plane, and it can be seen that various forms of distortion at the level of, for example, ±110 μm to 165 μm can occur due to individual differences in the frame portion 62.

[0028] Furthermore, according to the study by the present inventors, it has been found that a non-negligible deviation can also occur between the flatness of the support stage of the frame (frame portion) in a tensile welding machine for manufacturing a metal mask assembly, the reference plane such as a stone surface plate used in the inspection process, and the flatness of the substrate as the object to be vapor-deposited, with respect to the required vapor deposition accuracy. Therefore, it can be said that it is insufficient to simply bring the metal mask assembly into close contact with a reference plane prepared simply (that is, a reference plane with uneven flatness) during vapor deposition.

[0029] Note that there is also a frameless metal mask in which the mask sheet 61 and the frame portion 62 are integrated in the metal mask. It can be said that the frameless metal mask is less likely to generate distortion because no tension is applied, but it has the same problems in that the metal mask bends due to its own weight and it is insufficient to simply bring the metal mask into close contact with the reference plane. Also, in vertical vapor deposition, although the metal mask is less likely to bend due to its own weight compared to horizontal vapor deposition, it has the same problem in that it is insufficient to simply bring the metal mask into close contact with the reference plane (for example, a glass substrate).

[0030] <Posture control system> Next, a posture control system 1 of a metal mask (hereinafter, may be simply referred to as "this system 1", etc.) will be described with reference to FIGS. 2 to 5 as appropriate. Note that the X-axis, Y-axis, and Z-axis are shown in part of each drawing, and are drawn so that the directions of the respective axes are the directions shown in each drawing. In this example, the X-axis and Y-axis coincide with the horizontal direction, and the Z-axis coincides with the vertical direction.

[0031] This system 1 is a system that appropriately controls the posture of the metal mask by displacing each part of the metal mask. As shown in FIG. 2, this system 1 includes a posture control device 10, a sensor 20, a pressing mechanism 30, an input device 40, and an output device 50. The input device 40 and the output device 50 are additional elements and can be omitted.

[0032] FIG. 3 is a schematic diagram exemplifying the state of controlling the posture of a metal mask assembly 60 (an example of a metal mask) in a vapor deposition chamber, and FIG. 4 is a sectional view taken along line IV-IV thereof. Generally, a sensor 20, a pressing mechanism 30, and a stage 70 are provided in the vapor deposition chamber.

[0033] The stage 70 is a support base that supports the metal mask assembly 60 in the vapor deposition process. During vapor deposition, a glass substrate 90 is disposed above the metal mask assembly 60. A vapor deposition source 80 is disposed below the stage 70. The stage 70 has a frame shape having, for example, a rectangular opening so as not to block the vapor traveling from the vapor deposition source 80 toward the substrate 90. The upper surface of the stage 70 in this example is flat so that the metal mask assembly 60 can be held substantially horizontally. The metal mask assembly 60 is placed on the stage 70 or carried out from the stage 70 by another transfer device (for example, a robot arm) not shown. The stage 70 supports the metal mask assembly 60 at the frame portion 62.

[0034] The pressing mechanism 30 is an element for displacing the metal mask assembly 60. The pressing mechanism 30 is an example of the displacement part in the present technology. The pressing mechanism 30 typically displaces each part of the metal mask assembly 60 in its thickness direction (which may be the flying direction of the vapor deposition material). The pressing mechanism 30 includes, for example, a pressing part 31 that abuts against the frame part 62 of the metal mask assembly 60 and presses the frame part 62, and a driving part (not shown) that drives the pressing part 31 along the thickness direction of the metal mask assembly 60. The pressing part 31 of the pressing mechanism 30 is disposed above the stage 70. The driving mechanism of the pressing mechanism 30 is not particularly limited as long as it can press the pressing part 31 against the frame part 62. For example, it may be a hydraulic drive type pressing device, a pressing device by various actuators, a pressing device by a combination of a ball screw and a driving motor (e.g., a servo motor), a pressing device by a torque motor, etc.

[0035] In this example, a plurality of pressing parts 31 are provided along the outer edge of the metal mask assembly 60. In FIG. 3, for simplicity, for a rectangular metal mask assembly 60, a total of 16 pressing parts 31 are shown, one above each of the four corners and three above each of the spaces between adjacent corners. The pressing parts 31 are arranged at equal intervals on each short side and long side of the metal mask assembly 60. However, the number and arrangement of the pressing parts 31 are not limited to this. For example, the four corners of the metal mask assembly 60 correspond to the second positions in the present technology, and the second pressing parts 31B arranged above these second positions correspond to the second displacement parts in the present technology. Also, for example, the midpoints (e.g., the central points) of each short side and long side of the metal mask assembly 60 correspond to the first positions in the present technology, and the first pressing parts 31A arranged above these first positions correspond to the first displacement parts in the present technology.

[0036] The sensor 20 acquires marker information regarding the markers for posture confirmation provided on the metal mask. In this example, as described above, the posture confirmation markers are provided near the four corners of the frame portion 62 of the metal mask assembly 60, and the sensor 20 is provided above each installation position of these posture confirmation markers. The number and arrangement of the posture confirmation markers and the sensor 20 in the metal mask assembly 60 are not limited to this example and are independent of each other. The sensor 20 is arranged above the stage 70 at a position that does not interfere with the loading and unloading of the metal mask assembly 60 and the substrate 90.

[0037] The sensor 20 is not particularly limited as long as it can detect the position of the posture confirmation marker. For example, it may be an imaging device such as a CCD camera, a photoelectric sensor such as a laser sensor, other sensors, and combinations thereof (e.g., a camera-integrated laser displacement sensor), etc. Also, correspondingly, the marker information may be position information that can identify the position of the posture confirmation marker, or may be image information, etc. The sensor 20 in the present embodiment is a CCD camera, and the posture information is imaging information. The marker information acquired by the sensor 20 is sent to the posture control device 10.

[0038] <Posture control device> The posture control device 10 controls the driving of the pressing mechanism 30 in order to appropriately control the posture of the metal mask. As shown in FIG. 2, the posture control device 10 is mainly composed of a microcomputer having a processor (e.g., CPU), a memory (e.g., RAM, ROM, storage, etc.), and an interface (I / F), etc., and these are communicably connected to each other via, for example, a bus. Also, the posture control device 10 is communicably connected to the sensor 20, the pressing mechanism 30, the input device 40, the output device 50, etc. via wire or wireless. The posture control device 10 may be configured to cooperate with a vapor deposition control device (not shown), a substrate transfer device, etc., or may be a part of these devices.

[0039] The posture control device 10 includes, as functional components, a marker information acquisition unit 11, a posture information acquisition unit 12, and a displacement control unit 13. Each of these functional components is realized by a processor executing programs of these units stored in a memory such as a ROM.

[0040] The interface is a communication circuit that connects the posture control device 10 to a wired or wireless communication line, either wired or wirelessly. The memory is a storage means that stores an operating system, various programs, data, etc. read by the processor. The memory (an example of a storage unit) includes a RAM (Random Access Memory), a ROM (Read Only Memory), a storage, etc. The memory may have a solid state drive, a hard disk drive, etc., and a part of it may be provided separately from the processor.

[0041] The marker information acquisition unit 11 acquires marker information regarding the posture confirmation marker provided in the metal mask assembly 60. The marker information acquisition unit 11 acquires the marker information via, for example, the sensor 20. The marker information acquisition unit 11 may be configured to acquire marker information in a format comparable to the posture information based on the information received from the sensor 20 as needed. For example, the marker information acquisition unit 11 may be configured to calculate the position of the marker (e.g., XY coordinate position) based on the imaging information acquired from the sensor 20.

[0042] The posture information acquisition unit 12 acquires the posture information pre-associated with the metal mask assembly 60. The posture information acquisition unit 12 acquires, for example, the posture information pre-associated with the metal mask assembly 60 disposed on the stage 70.

[0043] The posture information is information regarding the posture of the metal mask (or the frame portion 62) when the metal mask realizes a desired opening pattern. For example, in the case of the metal mask assembly 60, it can be information that specifies the posture of the frame portion 62 such that no distortion or deflection occurs in the welded mask sheet 61 and a desired opening pattern is realized. Also, in the case of a frameless metal mask, it can be information that specifies the posture of the frameless metal mask such that no distortion or deflection occurs in the opening pattern.

[0044] Note that in the case of a frameless metal mask, a holding area without openings is provided around the pattern area where the opening pattern is provided. In the following description, the frame portion 62 in the metal mask assembly 60 can also be read by replacing it with the holding area in the frameless metal mask.

[0045] This posture information can be, for example, specifically, a combination (set) of the position information of each posture confirmation marker recorded during the manufacture of the metal mask. This posture information is typically determined as one set for one metal mask during the manufacture of the metal mask. For the metal mask assembly 60, for example, one set is determined for one frame portion 62. The posture information is recorded and managed, for example, in a database (DB) that stores management information regarding the metal mask. Note that when the metal mask is used a certain number of times, it is sent to a cleaning process and an inspection process. In the cleaning process, the deposited vapor deposition material on the mask is washed off, and in the inspection process, it is checked whether there is any shape change due to cleaning, deterioration, etc. For a metal mask that has deteriorated or undergone a shape change and does not meet the standard, for example, frame correction, replacement of the metal mask sheet, etc. are performed. Therefore, the posture information may be updated to more appropriate posture information re-acquired, for example, in the inspection process, the replacement process, etc.

[0046] The displacement control unit 13 controls the drive of the pressing unit 31 for displacing the frame portion 62 of the metal mask assembly 60. The displacement control unit 13 controls the drive of the pressing unit 31 based on the above marker information and posture information so that the posture of the metal mask based on the marker information and the posture of the metal mask based on the posture information satisfy a predetermined coincidence condition. Details of the drive control of the pressing unit 31 will be described later.

[0047] The input device 40 is an element that receives operations, instructions, etc. and sends a signal corresponding to the content to the processor. Examples of the input device 40 include operation buttons, keyboards, touch panels, mice, trackballs, stick input devices, voice input devices, and the like.

[0048] The output device 50 is an element that displays various information under the control of the processor. Examples of the output device 50 include a 7-segment display, a liquid crystal display, an OLED display, and the like.

[0049] <Method for Controlling the Posture of a Metal Mask> The operation of the posture control device 10 will be described with reference to FIGS. 5 to 7. The operation of the posture control device 10 can be understood as a posture control method. FIG. 6 is a flowchart of a method for controlling the posture of a metal mask according to an embodiment. The method for controlling the posture of a metal mask according to the present technology generally includes a step (S110) of acquiring the posture information of the metal mask assembly 60, a step (S120) of acquiring marker information, a step (S130) of determining whether the posture of the frame portion 62 is appropriate, and a step (S140) of displacing the frame portion 62. S110 and S120 may be performed in any order. Hereinafter, each step will be described.

[0050] The posture information acquisition unit 12 acquires the posture information pre-associated with the metal mask assembly 60 disposed on the stage 70 (S110). For example, the posture information acquisition unit 12 may acquire the posture information corresponding to the metal mask assembly 60 disposed on the stage 70 from a database (DB) storing the management information regarding the metal mask assembly 60. The posture information represents, for example, the positions of a plurality of posture confirmation markers during the manufacture of the metal mask assembly 60, for example, in XY coordinate positions. The posture information acquisition unit 12 stores the acquired posture information in the memory in association with, for example, the identification information (ID) of the metal mask assembly 60 or the frame portion 62.

[0051] The marker information acquisition unit 11 acquires, for example, marker information regarding the posture confirmation markers provided on the frame portion 62 of the metal mask assembly 60 disposed on the stage via the sensor 20 (S120). When there are a plurality of posture confirmation markers, the marker information acquisition unit 11 acquires marker information for each marker. In this example, the marker information acquisition unit 11 calculates the position (for example, XY coordinate position) of each marker based on the imaging information acquired from the sensor 20. The marker information acquisition unit 11 stores the acquired marker information in the memory, for example.

[0052] Then, the displacement control unit 13 determines whether the posture of the frame is appropriate (S130). The displacement control unit 13 determines whether the posture of the metal mask assembly 60 based on the marker information and the posture of the metal mask assembly 60 based on the posture information satisfy a predetermined matching condition. Specifically, for example, the displacement control unit 13 compares the set of position information of the posture confirmation markers recorded in advance as the posture information with the set of position information of the posture confirmation markers acquired by the marker information acquisition unit 11, and determines whether these satisfy a predetermined matching condition. The matching condition depends on the required vapor deposition accuracy, the arrangement of the substrate 90, the metal mask assembly 60, and the vapor deposition source 80. For example, it is exemplified that the error is within 3%.

[0053] When it is determined that the posture of the frame is appropriate (YES in S130), the displacement control unit 13 ends the control of the posture of the metal mask assembly 60. On the other hand, when it is determined that the posture of the frame is not appropriate (NO in S130), the displacement control unit 13 drives the pressing part 31 in the pressing mechanism 30 to displace the frame part 62 of the metal mask assembly 60 (S140).

[0054] At this time, as shown in FIG. 7, the displacement control unit 13 first displaces the first pressing part 31A among the pressing parts 31 (S210), and then displaces the second pressing part 31B among the pressing parts 31 (S220). The first pressing part 31A is a pressing part 31 that presses a first position near the midpoints of the long side and the short side of the frame part 62, that is, a position closer to the center than a predetermined reference (reference between the four corners and the midpoint). The second pressing part 31B is a pressing part 31 that presses a second position located at the four corners of the frame part 62, that is, a position farther from the center than a predetermined reference (reference between the four corners and the midpoint).

[0055] In this way, by first pressing a position closer to the center (the first displacement operation), as shown in FIG. 5, it is easier to manifest the inherent strain of the frame part 62 (and thus the metal mask assembly 60), and then by pressing a position farther from the center (the second displacement operation), it is easier to correct the strain of the frame part 62 to an appropriate position. Note that if the second pressing part 31B is first displaced to constrain the second position (the four corners), and then the first pressing part 31A is displaced to press the first position (the midpoint), it is difficult to release the strain of the frame part 62, so correction tends to be difficult. When a plurality of pressing parts are provided for one side of the frame part 62, it is preferable to drive the pressing parts in order from the pressing part near the midpoint of that side toward both ends.

[0056] The displacement amount of the first displacement operation with respect to the first position and the displacement amount of the second displacement operation with respect to the second position may be a predetermined fixed amount (for example, 10 μm, etc.), or may be a displacement amount predetermined for each pressing position based on the posture information.

[0057] Thereafter, the displacement control unit 13 returns to the process S120 again, and repeats the processes S120 to S140 until it is determined that the posture of the frame is appropriate. For example, the displacement control unit 13 may perform PID (Proportional-Integral-Differential) calculation on the driving amount of the pressing unit 31 so that the marker information matches the posture information, and output the result obtained by the PID calculation (for example, the driving current value composed of a digital signal) to the pressing mechanism 30 (an example of feedback control). Alternatively, the displacement control unit 13 may be configured to displace, for example, by a predetermined minute variable (+1 μm or -1 μm) at a time.

[0058] Thereby, the posture of the metal mask assembly 60 can be controlled to an appropriate posture capable of realizing a predetermined mask pattern. Therefore, for example, even if the flatness of the stage 70 deflects the metal mask assembly 60 from an appropriate posture, the metal mask assembly 60 can be set to an appropriate posture. Further, even when there is variation in the flatness of the stage 70 for each vapor deposition chamber, an appropriate posture of the metal mask assembly 60 can be realized without being affected by this.

[0059] <Vapor Deposition Process> In the vapor deposition process, the substrate 90 is conveyed into the vapor deposition chamber and disposed above the metal mask assembly 60. The substrate 90 is aligned (aligned) with the metal mask assembly 60. At this time, typically, first, using an optical sensor for alignment, the deviation (ΔX, ΔY, θ) between the substrate 90 and the metal mask assembly 60 at the center of the substrate 90 is detected and corrected. Thereafter, while maintaining the corrected posture, the substrate 90 is moved toward the metal mask assembly 60 (along the Z-axis direction).

[0060] Here, the movement of the substrate 90 in the Z-axis direction may be set, for example, until any one point of the substrate 90 abuts against the metal mask assembly 60. When abutting, it is desirable to prevent the posture of the metal mask assembly 60 from being displaced. Alternatively, the movement of the substrate 90 in the Z-axis direction may be set until the closest distance to the substrate reaches a predetermined value (for example, single-digit μm). Note that, for example, bringing the entire substrate 90 into close contact with the metal mask assembly 60 is not preferable because the mask sheet 61 may be bent into an undesirable posture. As a result, vapor deposition based on the opening pattern of the mask sheet 61 can be suitably realized.

[0061] <Configuration and Function and Effect> In the above Embodiment 1, the displacement control unit 13 controls the drive of the pressing mechanism 30 (displacement unit) based on the marker information and the posture information so that the posture of the metal mask based on the marker information and the posture of the metal mask based on the posture information satisfy a predetermined matching condition. According to such a configuration, the posture of the metal mask during vapor deposition in the vapor deposition process can be adjusted so that a desired mask pattern is realized. As a result, a decrease in vapor deposition accuracy due to the deflection of the metal mask can be suppressed. Subsequently, a decrease in vapor deposition accuracy due to the deflection of the metal mask can be suppressed.

[0062] In the above-described Embodiment 1, the displacement control unit 13 performs a first displacement operation of displacing the frame portion 62 of the metal mask assembly 60 by the pressing portion 31 (displacement portion) (S140). The marker information acquisition unit 11 acquires first marker information regarding a marker provided on the metal mask assembly 60 on which the first displacement operation has been performed (S120). The displacement control unit 13, based on the first marker information and the attitude information, performs a second displacement operation of displacing the frame portion of the metal mask by the displacement portion so that the attitude of the metal mask assembly 60 based on the first marker information and the attitude of the metal mask assembly 60 based on the attitude information satisfy a predetermined coincidence condition (S140). According to such a configuration, the frame portion of the metal mask can be displaced until the attitude of the metal mask satisfies a predetermined coincidence condition, in other words, until the attitude of the metal mask becomes appropriate. Thereby, the attitude of the metal mask can be appropriately controlled by a simpler method such as feedback control, for example.

[0063] In the above-described Embodiment 1, the pressing portion 31 (displacement portion) includes a first pressing portion 31A (first displacement portion) that displaces at least one first position closer to the center than a predetermined reference in the frame portion 62, and a second pressing portion 31B (second displacement portion) that displaces at least one second position farther from the center than a predetermined reference from the center of the frame portion 62. The displacement control unit 13 displaces the second position by the second pressing portion 31B after displacing the first position by the first pressing portion 31A. According to such a configuration, in order to control the attitude of the metal mask during vapor deposition based on the attitude information of the frame portion acquired during the manufacture of the metal mask assembly 60, vapor deposition can be performed with the metal mask assembly 60 in an attitude such that no bending or distortion occurs in the mask sheet 61. Note that, although not limited thereto, the above center may be the center of gravity, or may be the midpoint (center point) of a region along a predetermined direction at the periphery of the frame portion.

[0064] In the above-described Embodiment 1, the metal mask assembly 60 is rectangular, the second positions are the four corners of the metal mask, and the first position is located between the four corners of the metal mask. The displacement control unit 13 displaces at least one of the first positions, which is between the four corners of the metal mask assembly 60, by the first pressing portion 31A (first displacement portion), and then displaces at least one of the second positions, which are the four corners of the metal mask assembly 60, by the second pressing portion 31B (second displacement portion). When displacing the frame portion of the metal mask, if the corner portions of the outer shape of the metal mask are displaced first, the distortion of the metal mask will be confined between adjacent corner portions, and it may be difficult to control the metal mask to the target posture even if the portion between the adjacent corner portions is displaced. It is preferable to displace the portion between adjacent corner portions before displacing the corner portions of the outer shape of the metal mask, because the distortion of the metal mask becomes apparent and it becomes easier to control the metal mask to the target posture.

[0065] In the above-described Embodiment 1, the metal mask is a metal mask assembly 60 including a mask sheet 61 (mask sheet portion) having openings of a predetermined pattern and a frame portion 62 (supporting frame portion) that supports the mask sheet 61, and the attitude information is information regarding the attitude of the frame portion 62 at the time of manufacturing the metal mask assembly 60. In order to control the attitude of the metal mask during vapor deposition based on the attitude information of the frame acquired during the manufacture of the metal mask assembly 60 (MMA), the MMA can be controlled to an attitude in which bending and distortion of the mask sheet are less likely to occur, and vapor deposition can be performed.

[0066] In the above-described Embodiment 1, the marker information is the position information of markers provided on the metal mask assembly 60. As information for grasping the attitude of the metal mask, it is preferable to adopt the position information of the markers because it is simple while ensuring the required accuracy.

[0067] In the above-described Embodiment 1, the metal mask assembly 60 has a maximum dimension in a plan view of 1000 mm or more. The larger the dimension of the metal mask, the more likely it is to bend into a posture according to the surface form of the stage due to its own weight when placed on the stage. Therefore, when applying this technology to a metal mask that is likely to deflect due to its own weight, it is preferable because the advantages of this technology can be fully exerted.

[0068] In the above-described Embodiment 1, the metal mask assembly 60 is a metal mask for vapor deposition in the manufacture of an organic EL display panel. In the manufacture of an organic EL display, with the increase in the size and high definition of the display, it is required to vaporize finer RGB patterns on a larger substrate. For example, for a sixth-generation substrate or a substrate about half its size (6G half), fine patterns such as 600 to 1000 ppi are vaporized. Considering the deflection associated with the increase in the size of the metal mask, "vertical vapor deposition" in which the metal mask and the substrate are stood up for vapor deposition has been introduced. However, considering the size of the vapor deposition chamber and the handling property, it is more desirable to increase the size of the substrate size for which high-precision vapor deposition can be performed while the metal mask and the substrate are lying horizontally. According to this technology, for example, the substrate size for which high-precision vapor deposition can be performed while the metal mask and the substrate are lying horizontally can be increased further.

[0069] In the above-described Embodiment 1, the displacement portion is a pressing mechanism 30 (pressing portion) for pressing the frame portion of the metal mask, and the displacement control portion 13 controls the pressing amount of the pressing portion 31 in the pressing mechanism 30. Thereby, the posture of the metal mask can be appropriately controlled with a simpler configuration.

[0070] <Embodiment 2> The posture control system 1, the posture control device 10, and the posture control method according to the second embodiment will be described with reference to FIG. 8. In this embodiment, it is different from the first embodiment in that a machine learning model is stored in the memory (an example of a storage unit) of the posture control device 10. Note that redundant descriptions of the same structures, operations, and effects as those in the above-described first embodiment are omitted.

[0071] In the memory of this example, for example, a machine learning model learned for each frame portion 62 is stored. This machine learning model is learned, for example, with marker information and posture information as inputs, and drive information for driving the displacement portion so that the posture of the frame portion 62 based on the marker information and the posture of the frame portion 62 based on the posture information satisfy a predetermined coincidence condition as an output.

[0072] FIG. 8 is a flowchart of a method for controlling the posture of a metal mask according to an embodiment. The method for controlling the posture of the metal mask according to the present technology generally includes a step (S310) of acquiring marker information of the frame portion 62, a step (S320) of acquiring posture information, a step (S330) of determining whether the posture of the frame portion 62 based on each of the marker information and the posture information satisfies a predetermined coincidence condition, and a step (S340) of determining a pressing amount. S310 to S330 can be implemented in the same manner as in the first embodiment.

[0073] In step S340, the displacement control unit 13 controls the driving of the displacement portion based on the control information output when the marker information and the posture information are input to the machine learning model.

[0074] The frame portion 62 is used over a long period of time by replacing the mask sheet 61, for example, as compared with a frameless metal mask. In addition, even if the frame portions 62 are of the same production lot, differences in subsequent warping conditions (for example, warps) may occur depending on the metal structure and cutting position of the metal plate used as the material. Therefore, it is useful to derive, for each frame portion 62, parameters for displacement control for eliminating the warping according to the warping mode using a machine learning model.

[0075] The machine learning method is not particularly limited and may be any of supervised learning, unsupervised learning, and reinforcement learning. For example, it may be supervised learning based on data acquired in a real environment, reinforcement learning for predicting parameters necessary to achieve maximization of a state value function in a real environment or a virtual environment, or a combination thereof. Examples of supervised machine learning algorithms include neural networks, k-nearest neighbor methods, SVM (Support Vector Machine), etc. Examples of reinforcement learning algorithms include SAC (Soft Actor Critic), TD3 (Twin Delayed Deep Deterministic Policy Gradient), MPO (Maximum-a-posteriori Policy Optimization), DDPG (Deep Deterministic Policy Gradient), etc.

[0076] According to such a configuration, for example, it is suitable because there is no need for repetitive control such as feedback control. Further, the metal mask is washed after being used for vapor deposition a plurality of times and then placed on the stage again. At this time, although the degree of deflection of the metal mask is different each time the stage on which it is placed changes, the tendency of the displacement amount to be controlled is likely to appear for each identical stage and / or for each identical metal mask. On the other hand, if an attempt is made to precisely match the metal mask to the target posture, it is necessary to increase the displacement position of the metal mask, and the number and accuracy of the parameters to be controlled increase. Therefore, it is preferable to use a machine learning model learned based on machine learning that takes marker information and posture information as inputs and outputs control information for the displacement part, because the posture of the metal mask can be controlled more precisely and simply.

[0077] <Other Embodiments> The technology disclosed herein is not limited to the embodiments described by the above description and drawings, and for example, the following embodiments are also included in the technical scope.

[0078] [1] The displacement portion may be realized by an offensive force other than the pressing mechanism. The displacement portion may be, for example, a displacement mechanism using an electromagnetic magnet, a displacement mechanism using a suction device, or a combination thereof.

[0079] [2] The displacement positions of each side of the frame portion and the number of pressing portions are not limited to the above examples. For each side, one at each end and three or more between them may be provided. The displacement positions and pressing portions at the ends (corners) of adjacent sides may overlap. Depending on the size of the frame portion, the number of displacement positions and pressing portions is exemplified to be, for example, between 3 and 50, between 3 and 20, or between 5 and 10.

[0080] [3] The number of acquisition positions of the attitude information and the marker information is not limited to the above examples. The acquisition positions of the attitude information and the marker information may be, for example, one at each end and three or more between them for each side of the frame portion. The acquisition positions of the attitude information and the marker information at the ends (corners) of adjacent sides may overlap. Depending on the size of the frame portion, the number of acquisition positions of the attitude information and the marker information is exemplified to be, for example, between 3 and 50, between 3 and 20, or between 5 and 10.

[0081] [4] The coincidence condition between the attitude of the metal mask based on the marker information and the attitude of the metal mask based on the attitude information is not limited to satisfying the threshold condition regarding the error amount between the marker information and the attitude information. For example, further considering the surface form information of the substrate (more specifically, the surface form information of the peripheral portion of the substrate), the attitude of the metal mask with respect to the substrate may satisfy a predetermined coincidence condition with the attitude of the metal mask based on the attitude information. According to such a configuration, it is possible to suppress the variation in the deposition pattern based on the difference in the surface form of each substrate.

[0082] [5] In Embodiment 2, the pressing operation is only performed once. However, even when determining the displacement amount using, for example, a machine learning model, marker information may be acquired after the displacement (for example, S310), and it may be determined whether the posture of the frame portion 62 is appropriate (S330). Here, when the posture of the frame portion 62 is not appropriate (NO in the second and subsequent S330), the subsequent displacement amount of the frame portion may be determined using a machine learning model (S340), or may be determined without using a machine learning model (S140).

Explanation of Signs

[0083] 1... Posture control system, 10... Posture control device, 11... Marker information acquisition unit, 12... Posture information acquisition unit, 13... Displacement control unit, 20... Sensor, 30... Pressing mechanism, 31... Pressing portion, 31A... Pressing portion, 31B... Pressing portion, 40... Input device, 50... Output device, 60... Metal mask assembly, 61... Mask sheet, 62... Frame portion, 70... Stage, 80... Evaporation source, 90... Substrate

Claims

1. A marker information acquisition unit that acquires marker information regarding a marker provided on a metal mask; An attitude information acquisition unit that acquires attitude information pre-associated with the metal mask; A displacement control unit that controls the driving of a displacement unit for displacing a frame portion of the metal mask; comprising The displacement control unit controls the driving of the displacement unit so that the attitude of the metal mask based on the marker information and the attitude of the metal mask based on the attitude information satisfy a predetermined coincidence condition. An attitude control device for a metal mask.

2. The displacement control unit performs a first displacement operation for displacing a frame portion of the metal mask by the displacement unit, The marker information acquisition unit acquires first marker information regarding a marker provided on the metal mask subjected to the first displacement operation, The displacement control unit performs a second displacement operation for displacing the frame portion of the metal mask by the displacement unit so that the attitude of the metal mask based on the first marker information and the attitude of the metal mask based on the attitude information satisfy a predetermined coincidence condition. The attitude control device for a metal mask according to Claim 1.

3. The displacement unit A first displacement unit that displaces at least one first position closer to the center than a predetermined reference in the frame portion; A second displacement unit that displaces at least one second position farther from the center than a predetermined reference from the center of the frame portion; comprising The displacement control unit displaces the second position by the second displacement unit after displacing the first position by the first displacement unit. The attitude control device for a metal mask according to Claim 1.

4. The metal mask is rectangular, the second position is at the four corners of the metal mask, and the first position is located between the four corners of the metal mask. After the displacement control unit displaces at least one of the first positions between the four corners of the metal mask by the first displacement unit, the displacement control unit displaces at least one of the second positions at the four corners of the metal mask by the second displacement unit. The metal mask attitude control device according to claim 3.

5. The metal mask is a metal mask assembly including a mask sheet portion having openings in a predetermined pattern and a support frame portion supporting the mask sheet portion. The attitude information is information regarding the attitude of the support frame portion during the production of the metal mask assembly. The metal mask attitude control device according to claim 1.

6. The marker information is position information of markers provided on the metal mask. The metal mask attitude control device according to claim 1.

7. The metal mask has a maximum dimension in a plan view of 1000 mm or more. The metal mask attitude control device according to claim 1.

8. The metal mask is a vapor deposition metal mask for manufacturing an organic EL display panel. The metal mask attitude control device according to claim 1.

9. The displacement unit is a pressing unit for pressing a frame portion of the metal mask. The displacement control unit controls the pressing amount of the pressing unit. The metal mask attitude control device according to claim 1.

10. The device further includes a storage unit that stores a machine learning model learned based on machine learning that takes the marker information and the attitude information as inputs and outputs control information for the displacement unit. The displacement control unit controls the drive of the displacement unit based on control information output when the marker information and the attitude information are input to the machine learning model. The attitude control device for a metal mask according to claim 1.

11. Obtain marker information regarding a marker provided on a metal mask disposed on a stage, Obtain attitude information pre-associated with the metal mask, Based on the marker information and the attitude information, displace the frame portion of the metal mask so that the attitude of the metal mask based on the marker information and the attitude of the metal mask based on the attitude information satisfy a predetermined coincidence condition. A method for controlling the attitude of a metal mask.

12. A program for causing a computer to execute each step of the method according to claim 11.

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