Mask conveying apparatus, film forming apparatus, and mask shape detecting method

Abstract

The present invention provides a mask conveying device, a film forming device, and a mask shape detection method capable of detecting changes in mask shape. The mask conveying device is characterized by comprising: a first conveying roller (4a) for conveying a mask (7); a second conveying roller (4b) for further conveying the mask (7) conveyed by the first conveying roller (4a) downstream; a detection member for detecting a value related to the torque variation of the first conveying roller (4a) and the second conveying roller (4b); and a mask shape detection member for detecting the shape of the mask (7) based on the value detected by the detection member.

Description

Technical Field

[0001] The present invention relates to a mask transport device, a film forming apparatus, and a mask shape detection method for a mask that overlaps with a substrate during film formation on a substrate. Background Technology

[0002] For example, as a method for forming a thin film on a substrate for manufacturing an organic EL display, a method is known to form a film with a predetermined pattern on the substrate by forming a film on the substrate through a mask with openings of a predetermined pattern. In this method, after aligning the mask with the substrate, film formation is performed while the mask and substrate are in close contact. In order to form a film with high precision using this method, it is necessary to align the mask and the substrate with high precision and to perform film formation while maintaining this alignment.

[0003] As an apparatus for manufacturing organic EL displays, an in-line type apparatus is known that deposits film while transporting the substrate and mask in an overlapping state. In this in-line type apparatus, the film deposition process is performed continuously after the substrate and mask positioning process. After positioning the substrate and mask, they are transported into the deposition chamber, and film deposition is performed while transporting. Typically, in the manufacture of organic EL displays, thin sheets such as glass or resin are used as substrates. If the size of the substrate increases, the deflection when holding the substrate horizontally increases. Therefore, it is difficult to transport the substrate separately; thus, a substrate carrier for holding the substrate is usually used.

[0004] In the tandem apparatus configured as described above, the substrate before film deposition is fed into the apparatus and held on a substrate carrier. Then, the substrate and mask are aligned (positioned) and overlapped, and film deposition is performed while the substrate is being conveyed. The substrate with only film deposition is then conveyed to the next process, while the substrate carrier and mask return upstream for reuse in film deposition. Thus, in a tandem apparatus, the substrate carrier and mask typically circulate continuously within the production line.

[0005] In this structure, the mask and substrate carrier circulate within the production line, and are therefore heated during each film deposition process. With the chamber in a vacuum during the return of the mask and substrate carrier to the upstream, heat dissipation is difficult. Therefore, the next film deposition begins before the accumulated temperature has completely decreased, causing the temperature of the substrate carrier and mask to rise with each rotation. Depending on the manufacturing conditions, sometimes the next film deposition is performed after the rotation at a temperature more than 60°C higher than before. For example, the substrate size of G8 is 2200×2500mm, and the corresponding mask and substrate carrier have a length and width of approximately 3000mm. The thermal expansion at this time is more than 3mm for SUS material and more than 4mm for aluminum material, causing a change in the shape of the mask.

[0006] Therefore, in the case of a tandem device as described above, the mask is typically removed from the production line and maintained after a predetermined number of film depositions, thereby improving the yield. For example, a control system is assembled in which a unique ID is assigned to each mask fed into the device in the computer that manages the entire device, the conveying status is monitored, thresholds are set based on the conveying path length and the number of film depositions, and the mask is removed from the device when the threshold is reached.

[0007] However, not only thermal expansion, but also sudden disturbances such as collisions between masks causing shape changes make it impossible to detect mask shape using the above methods. Therefore, if a mask with a changed shape is used, even if time is spent on positioning the mask and substrate, misalignment may occur during transport, leading to a decrease in yield.

[0008] It should be noted that, in the technology disclosed in Patent Document 1, although the mechanical deterioration of the roller conveyor can be determined, the shape of the mask cannot be detected.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: Japanese Patent Application Publication No. 2005-311259 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] As mentioned above, in conventional devices, the mask being transported is used directly even if its shape changes due to certain influences, which can sometimes have adverse effects. For example, it can sometimes lead to reduced film formation accuracy or reduced yield.

[0014] The purpose of this invention is to provide a mask conveying device, a film forming device, and a mask shape detection method capable of detecting mask shape.

[0015] Solution for solving the problem

[0016] To address the aforementioned issues, the present invention employs the following solution.

[0017] That is, the mask conveying device of the present invention is characterized by comprising:

[0018] A first conveyor roller, the first conveyor roller conveys the mask;

[0019] A second conveying roller further conveys the mask conveyed by the first conveying roller downstream.

[0020] A detection component that detects values ​​related to torque variations of the first and second conveyor rollers; and

[0021] A mask shape detection component that detects the shape of the mask based on values ​​detected by the detection component.

[0022] Invention Effects

[0023] As explained above, according to the present invention, the shape of a mask can be detected. Attached Figure Description

[0024] Figure 1 This is a schematic diagram showing the mask conveying device.

[0025] Figure 2 This is a schematic diagram of the block diagram representing the mask shape detection unit.

[0026] Figure 3 (a) to (b) are schematic diagrams showing the torque value waveforms of the mask used for reference value determination.

[0027] Figure 4 (a) to (b) are schematic diagrams showing the torque value waveforms of a concave mask.

[0028] Figure 5 (a) to (b) are schematic diagrams showing the torque waveforms of a convex mask.

[0029] Figure 6 This is a schematic diagram illustrating an example of a tandem film-forming apparatus.

[0030] Figure 7 (a) to (b) are explanatory diagrams of organic EL display devices.

[0031] Explanation of reference numerals in the attached figures

[0032] 1 Servo Motor

[0033] 1a First servo motor

[0034] 1b Second servo motor

[0035] 4 Conveyor Rollers

[0036] 4a First conveyor roller

[0037] 4b Second conveyor roller

[0038] 6 substrate

[0039] 7. Mask

[0040] 10 Mask Shape Detection Unit

[0041] 11 Control Department

[0042] 33. Substrate mask assembly

[0043] 35 Film-forming section Detailed Implementation

[0044] Hereinafter, with reference to the accompanying drawings, embodiments for carrying out the present invention will be described in detail illustratively. However, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of the structural components described in these embodiments are not intended to limit the scope of the present invention.

[0045] (Example)

[0046] Reference Figures 1 to 7 This document describes a mask transport device for a mask 7 that overlaps with a substrate 6 during film deposition on a substrate, a film deposition apparatus equipped with a mask transport device, and a mask shape detection method. The film deposition apparatus of this embodiment is a series-type apparatus that performs film deposition while transporting the substrate 6 and the mask 7 in a positioned state; for example, it is used as an apparatus for manufacturing organic EL displays. In this film deposition apparatus, a mask transport device is provided for transporting the mask 7.

[0047] <Overview of Mask Conveying Device>

[0048] The following is a special reference. Figure 1 as well as Figure 6 The outline of the mask conveying device is described below. Figure 1 This is a top schematic view showing an example of the mask transport device included in the film forming apparatus of this embodiment. Figure 6 This represents a schematic diagram of the tandem film-forming apparatus of this embodiment.

[0049] In this embodiment, for example, a substrate 6 made of alkali-free glass with a size referred to as eighth generation (specifically 2500mm × 2200mm × 0.5mm) is preferably used. However, the material and size of the substrate that can be used in this invention are not particularly limited. The substrate 6 is placed on a mask 7. When using the aforementioned eighth-generation substrate 6, for example, a mask 7 with a size of 2900mm × 2500mm × 50mm is preferably used. On the substrate 6, TFT circuits are formed if it is an organic EL display, and electrodes are formed if it is an organic EL illumination.

[0050] like Figure 6 As shown, substrate 6 is inserted into substrate insertion section 31. Then, in substrate insertion section 31, a decompression process is performed from atmospheric pressure to a predetermined pressure using a vacuum pump (not shown). For example, the decompression process is performed until the pressure reaches 5.0 × 10⁻⁶. -4Below Pa. After the depressurization process in the substrate input section 31, a plate-shaped valve, called a gate valve, located between the substrate input section 31 and the substrate transport section 32, is opened. At this time, the pressure in the substrate transport section 32 is set lower than that in the substrate input section 31 (for example, set to 1.0 × 10 Pa). -4 (Pressure below Pa). When the substrate 6 is transported to a predetermined position within the substrate transport section 32, the gate valve located between the substrate input section 31 and the substrate transport section 32 is closed. Afterwards, the substrate 6 is transported from the substrate transport section 32 to the substrate mask assembly section 33.

[0051] In the substrate-mask assembly section 33, the alignment of the substrate 6 and the mask 7 is performed by an alignment mechanism (not shown). In this embodiment, the substrate 6 and the mask 7 are aligned and then assembled after being centered in the substrate-mask assembly section 33. However, alignment marks can also be provided on the substrate 6 and the mask 7 to perform an alignment operation based on image processing.

[0052] With the substrate 6 mounted on the mask 7, they are conveyed by multiple conveyor rollers 4 in the following order: substrate-mask assembly 33, chasing part 34, film-forming part 35 (as a film-forming component), separating part 36, and substrate-mask separation part 37. In the mask conveying device of this embodiment, a pair of conveyor rollers 4 arranged on both sides in a direction perpendicular to the conveying direction A of the mask 7 are grouped together, and multiple groups of conveyor rollers 4 are arranged along the conveying direction A. These conveyor rollers 4 are respectively connected to the magnetic seal 3 and are connected to the servo motor 1 via a coupling 2 arranged on the outside of a chamber configured to create an internal vacuum environment. Figure 1 As shown, each conveying roller 4 is preferably connected to each servo motor 1. The multiple servo motors 1 are controlled by a controller (not shown) to ensure synchronous rotation of the multiple conveying rollers 4. It should be noted that while the multiple servo motors 1 are synchronously controlled for conveying the mask 7, the mask 7 may bend due to factors such as the assembly precision of the machinery. Therefore, in the mask conveying device of this embodiment, side rollers 5 are provided between the conveying rollers 4 adjacent to each other relative to the conveying direction A to suppress the bending movement of the mask 7.

[0053] Furthermore, in this embodiment, a mask shape detection unit 10, serving as a mask shape detection member, is provided in the film formation section 35. In this mask shape detection unit 10, if the mask shape is detected to be within a predetermined range, the substrate 6 and mask 7 are separated in the substrate-mask separation section 37, and the mask 7 is then transported back to the substrate-mask assembly section 33 via the mask return section 41. That is, the mask 7 returns to the transport path used for film formation. Conversely, if the mask shape is detected to be outside the predetermined range, in the mask shape detection unit 10, the substrate 6 and mask 7 are separated in the substrate-mask separation section 37, and the mask 7 is transported to the mask discharge section 43. That is, the mask 7 is transported outside the transport path used for film formation.

[0054] In this embodiment, the mask conveying apparatus includes a first conveying roller 4a for detecting the mask shape and a second conveying roller 4b for further conveying the mask 7 conveyed by the first conveying roller 4a downstream. The mask shape detection unit 10 is configured to detect the shape of the mask 7 by using a detection member that detects values ​​related to torque variations of the first and second conveying rollers 4a and 4b. It should be noted that the detection member detects values ​​related to torque variations of these conveying rollers based on the drive torque of the first servo motor 1a that rotates the first conveying roller 4a and the drive torque of the second servo motor 1b that rotates the second conveying roller 4b.

[0055] <Mask Shape Detection Department>

[0056] In particular, refer to Figure 2 The mask shape detection unit 10 will be described in more detail. Figure 2This is a block diagram showing the mask shape detection unit 10. In the control unit 11 of the mask shape detection unit 10, similar to the other servo motors 1, speed commands are sent to the motion controller 12 to control the first servo motor 1a and the second servo motor 1b used for detecting the mask shape. The motion controller 12 sends a preset speed command to the servo motor amplifier 13. The servo motor amplifier 13 rotates the first servo motor 1a and the second servo motor 1b according to the received speed command. Then, the encoder signals of these servo motors are returned to the motion controller 12 as speed FB (feedback), thereby causing the first servo motor 1a and the second servo motor 1b to rotate at a constant speed. When the mask 7 passes through the first conveyor roller 4a and the second conveyor roller 4b, which are rotating at a constant speed using the first servo motor 1a and the second servo motor 1b, the load acting on each servo motor varies depending on the weight and shape of the mask 7. Even with such load variations, the torque value of each servo motor is controlled to maintain a constant speed. The value related to the torque variation at this time is detected by the control unit 11, which also functions as a detection component. The control unit 11 detects the shape of the mask 7 by comparing the detected value with a reference value related to the torque variation. It should be noted that the speed based on the speed command mentioned above can be set to, for example, 40 mm / s. Of course, this speed can be set appropriately according to the size of various components.

[0057] <Mask Shape Detection Method>

[0058] In particular, refer to Figures 3-5 The mask shape detection method of this embodiment will be described below. In this embodiment, firstly, the control unit 11 detects a value related to the torque variation of the first conveyor roller 4a when the mask 7 is conveyed by the first conveyor roller 4a, based on the torque value of the first servo motor 1a (first step). Next, the control unit 11 detects a value related to the torque variation of the second conveyor roller 4b when the mask 7 conveyed by the first conveyor roller 4a is further conveyed downstream by the second conveyor roller 4b, based on the torque value of the second servo motor 1b (second step). Next, the mask shape detection unit 10 detects the shape of the mask 7 by comparing the values ​​detected by the first and second steps with a reference value (third step). Hereinafter, a specific method for detecting the shape of the mask 7 will be described. It should be noted that a current value corresponding to the torque value may also be obtained instead of the torque value.

[0059] <<Benchmark Value>>

[0060] The control unit 11 includes a storage component (ROM, RAM, etc.) for storing values ​​related to torque variations detected by the control unit 11. Furthermore, the value detected by the control unit 11 when transmitting the reference value measurement mask is stored as a reference value in the storage component, and the mask shape detection unit 10 uses the reference value stored in the storage component to detect the shape of the mask 7. It should be noted that the reference value measurement mask is a flat, non-warped mask. That is, the reference value measurement mask is a mask whose shape is guaranteed within a specified range, and it is used to obtain the torque waveform as a reference during mask shape detection.

[0061] Figure 3 This is a graph illustrating the variation in torque values ​​of the first servo motor 1a and the second servo motor 1b as the mask 7 used for reference value measurement is conveyed by the first conveyor roller 4a and the second conveyor roller 4b. The left side of the graph shows the mask 7 being conveyed, and the right side shows the waveform representing the variation in torque values. It should be noted that in the graph, the horizontal axis of the curve on the right side represents time, and the vertical axis represents torque value.

[0062] Figure 3 (a) is a diagram illustrating the variation in torque value when the mask 7 used for reference value measurement is conveyed via the first conveyor roller 4a. When the mask 7 is placed on the first conveyor roller 4a, a load is applied to the first servo motor 1a, and its speed is reduced. Therefore, as described above, the torque value of the first servo motor 1a increases and then gradually decreases in order to keep the rotational speed of the first conveyor roller 4a constant.

[0063] Figure 3 (b) is a graph illustrating the variation in torque value when the mask 7 used for reference value measurement is conveyed via the second conveyor roller 4b. It should be noted that the graph on the right also shows waveform 20 representing the variation in torque value of the first servo motor 1a. As shown in the figure, it can be seen that waveform 20 representing the variation in torque value of the first servo motor 1a and waveform 21 representing the variation in torque value of the second servo motor 1b have the same shape.

[0064] In waveform 20, which represents the change in torque value of the first servo motor 1a, the torque value at which the torque value reaches its peak is set as I1, and the time from the start of the torque value increase to the convergence is set as T1. Similarly, in waveform 21, which represents the change in torque value of the second servo motor 1b, the torque value at which the torque value reaches its peak is set as I2, and the time from the start of the torque value increase to the convergence is set as T2. Furthermore, the time from the start of the torque value increase in waveform 20 to the start of the torque value increase in waveform 21 is set as dT1.

[0065] To detect the shape of mask 7, several values ​​related to torque variation can be used. In this embodiment, the case where the time from the start of the torque value of the first conveyor roller 4a (equivalent to the torque value of the first servo motor 1a) to the start of the start of the torque value of the second conveyor roller 4b (equivalent to the torque value of the second servo motor 1b) is used. In this case, the aforementioned time dT1 is stored in the storage unit provided by the control unit 11.

[0066] When conveying the mask 7 for film formation, the torque values ​​of the first servo motor 1a and the second servo motor 1b are detected in the same manner as when conveying the mask 7 for reference value measurement. Next, the control unit 11 compares the time from when the torque value of the first conveying roller 4a begins to rise to when the torque value of the second conveying roller 4b begins to rise with time dT1. If the difference is within a predetermined range (threshold), the mask shape detection unit 10 determines that the mask shape is within a specified range. On the other hand, if the difference exceeds the predetermined range, the mask shape detection unit 10 determines that the mask shape is outside the specified range.

[0067] <<The case of a mask deformed into a concave shape>>

[0068] Figure 4 This diagram illustrates the variation in torque values ​​of the first servo motor 1a and the second servo motor 1b as the mask 7, deformed into a concave shape, is conveyed by the first conveyor roller 4a and the second conveyor roller 4b. The left side of the diagram shows the mask 7 being conveyed, and the right side shows the waveform representing the variation in torque values. It should be noted that in the diagram, the horizontal axis of the curve on the right represents time, and the vertical axis represents torque value.

[0069] Figure 4 (a) is a graph illustrating the variation in torque value when the mask 7, deformed into a concave shape, is conveyed by the first conveying roller 4a. In the graph on the right, waveform 22 is represented by a solid line, which represents the variation in torque value of the first servo motor 1a when conveying the mask 7, and waveform 20 is represented by a dashed line.

[0070] Figure 4 (b) is a graph illustrating the variation in torque value when the mask 7, deformed into a concave shape, is conveyed by the second conveying roller 4b. In the graph on the right, waveform 23 and waveform 22 are represented by solid lines. Waveform 23 represents the variation in torque value of the second servo motor 1b when conveying the mask 7. Waveforms 20 and 21 are represented by dashed lines.

[0071] In the waveform 22 representing the variation of the torque value of the first servo motor 1a, the torque value when the torque value reaches the peak is set as I3, and the time from when the torque value starts to rise until it converges is set as T3. Further, in the waveform 23 representing the variation of the torque value of the second servo motor 1b, the torque value when the torque value reaches the peak is set as I4, and the time from when the torque value starts to rise until it converges is set as T4. Furthermore, the time from when the torque value starts to rise in the waveform 22 until the torque value starts to rise in the waveform 23 is set as dT2.

[0072] According to the graph, I3, I4 < I1, I2, and dT1 < dT2. That is, by detecting I3, I4 < I1, I2 or dT1 < dT2, it is possible to detect that the mask 7 is deformed into a concave shape. Moreover, in this embodiment, if dT2 - dT1 is within a predetermined range (threshold), the mask shape detection unit 10 determines that the mask shape is within the specified range. On the other hand, when dT2 - dT1 exceeds the predetermined range, the mask shape detection unit 10 determines that the mask shape is outside the specified range.

[0073] <<Case of a mask deformed into a convex shape>>

[0074] Figure 5 It is a diagram showing the variation of the torque values of the first servo motor 1a and the second servo motor 1b when the mask 7 deformed into a convex shape is conveyed by the first conveying roller 4a and the second conveying roller 4b. The conveyance of the mask 7 is shown on the left side of the figure, and the waveform representing the variation of the torque value is shown on the right side of the figure. It should be noted that in the figure, the horizontal axis of the graph on the right side is time, and the vertical axis is the torque value.

[0075] Figure 5 (a) is a diagram showing the variation of the torque value when the mask 7 deformed into a convex shape is conveyed by the first conveying roller 4a. In the graph on the right side, the waveform 24 is represented by a solid line, and this waveform 24 represents the variation of the torque value of the first servo motor 1a when conveying this mask 7, and the above waveform 20 is represented by a dashed line.

[0076] Figure 5 (b) is a diagram showing the variation of the torque value when the mask 7 deformed into a convex shape is conveyed by the second conveying roller 4b. In the graph on the right side, the waveforms 25 and the above waveform 24 are represented by solid lines, and this waveform 25 represents the variation of the torque value of the second servo motor 1b when conveying this mask 7, and furthermore, the above waveforms 20 and 21 are represented by dashed lines.

[0077] In waveform 24, which represents the change in torque value of the first servo motor 1a, the torque value at which the torque value reaches its peak is set as I5, and the time from the start of the torque value increase to the convergence is set as T5. Similarly, in waveform 25, which represents the change in torque value of the second servo motor 1b, the torque value at which the torque value reaches its peak is set as I6, and the time from the start of the torque value increase to the convergence is set as T6. Furthermore, the time from the start of the torque value increase in waveform 24 to the start of the torque value increase in waveform 25 is set as dT3.

[0078] As shown in the graph, I5, I6 > I1, I2, and dT1 > dT3. That is, by detecting I5, I6 > I1, I2 or dT1 > dT3, it is possible to detect that the mask 7 has deformed into a convex shape. Furthermore, in this embodiment, if dT3-dT1 is within a predetermined range (threshold), the mask shape detection unit 10 determines that the mask shape is within the specified range. On the other hand, if dT3-dT1 exceeds the predetermined range, the mask shape detection unit 10 determines that the mask shape is outside the specified range. It should be noted that the reason for I5, I6 > I1, I2 is due to the impact generated when the front end of the mask 7 abuts against the top of the conveyor roller 4.

[0079] <Film Forming Device>

[0080] Reference Figure 6 The film deposition apparatus in a series configuration will be described in more detail. During film deposition, a substrate 6 is inserted into the substrate insertion section 31. The substrate 6 is inserted into the substrate insertion section 31 with its lower surface as the film deposition surface. In the substrate insertion section 31, the pressure is reduced to below a predetermined pressure by a vacuum pump (not shown) connected to the substrate insertion section 31. When the chamber volume of the substrate insertion section 31 is small, the time spent venting is short; therefore, it is preferable to perform the operation of aligning the film deposition surface of the substrate 6 with the lower surface in the early stages of inserting the substrate into the substrate insertion section 31.

[0081] After venting the substrate in the substrate input section 31 until the pressure reaches a predetermined level, the substrate 6 is transported by a vacuum transport robot 44 installed in the substrate transport section 32. Specifically, the vacuum transport robot 44 transports the substrate 6 by receiving it from the substrate input section 31. A plate-shaped valve that can be opened and closed is installed between the substrate input section 31 and the substrate transport section 32. Then, the vacuum transport robot 44 rotates toward the substrate input section 31, extends its arm to the lower surface of the substrate 6 placed in the substrate input section 31, and lifts it up to receive the substrate 6. The vacuum transport robot 44, having received the substrate 6, feeds the substrate 6 into the substrate transport section 32. After the substrate 6 has been fed into the substrate transport section 32 and reached a predetermined position, the plate-shaped valve that can be opened and closed is installed between the substrate input section 31 and the substrate transport section 32 and closes. A buffer section for storing the substrate 6 and a pretreatment section for activating the film-forming surface of the substrate 6 may also be provided in the substrate transport section 32 as needed.

[0082] Next, the vacuum transfer robot 44 delivers the substrate 6, which has been fed into the substrate transport section 32, to the substrate mask assembly section 33. At this time, the mask 7 is pre-inserted into the substrate mask assembly section 33 from the mask return section 41 or the mask insertion section 40. Then, the plate-shaped valve that can be opened and closed, located between the substrate transport section 32 and the substrate mask assembly section 33, is opened. Afterward, the vacuum transfer robot 44 rotates toward the substrate mask assembly section 33, delivering the substrate 6 to the substrate receiving section (not shown) located in the substrate mask assembly section 33. Then, the vacuum transfer robot 44 returns to a predetermined position within the substrate transport section 32, and the plate-shaped valve that can be opened and closed, located between the substrate transport section 32 and the substrate mask assembly section 33, is closed.

[0083] The substrate 6, which is transferred to the substrate receiving portion of the substrate-mask assembly 33, is placed on the mask 7. At this time, alignment is preferably performed using an alignment mechanism that aligns the substrate 6 and the mask 7. Furthermore, it is more preferable to place a component on the substrate 6 placed on the mask 7 to improve the tightness of the contact between the mask 7 and the substrate 6. Specifically, it is preferable to place a component utilizing a magnet or a component having a mechanism for adjusting the shape of the substrate.

[0084] After the mask 7 and substrate 6 are overlapped at the substrate mask assembly section 33, they are conveyed to the follow-up section 34 in an overlapping state. The aforementioned mask conveying device is provided from the substrate mask assembly section 33. Thus, the mask 7 and substrate 6 are conveyed together by multiple conveying rollers 4 that contact the lower surface of the mask 7 with the substrate 6 overlapping it. In the follow-up section 34, an operation is performed to reduce the gap between the mask 7 that was previously assembled with the substrate 6. Specifically, while the previous mask 7 is being conveyed at the film-forming speed, the subsequent mask 7 is being conveyed at a speed higher than the film-forming speed, thereby reducing the gap. Then, by conveying the subsequent mask 7 at the film-forming speed, the desired gap can be achieved. The narrower the gap, the less waste of film-forming material can be reduced; therefore, it is preferable that there is no gap between the masks. However, if the masks are in contact with each other, particles or the like can form; therefore, it is preferable to ensure a minimum gap.

[0085] In the chasing section 34, while maintaining the state of reducing the spacing between the masks, the overlapping masks 7 and substrate 6 are transported to the film forming section 35. During the transport process, the posture of the mask 7 is detected, and the substrate 6 is formed while performing posture control.

[0086] A film-forming source (not shown) is provided in the film-forming section 35. It should be noted that, regarding the film-forming source, an evaporation source is provided in the case of vacuum evaporation, a target is provided in the case of sputtering, and an electrode and a flow path for the film-forming gas are provided in the case of CVD. In this embodiment, the case of vacuum evaporation is given as an example, but the attitude control and transport control of the mask 7 are the same in sputtering and CVD.

[0087] In the film-forming section 35, multiple layers of film are typically formed on the substrate 6. An evaporation source, serving as the film-forming source, is fixed, and while the overlapping masks 7 and the substrate 6 are moved, a desired film is deposited on the substrate 6 to form a thin film. For monochromatic emitting organic EL devices, a mask 7 with openings in the emitting regions is used. For multicolor emitting organic EL devices, a mask 7 with openings in regions where each color is desired to be formed is used. In tandem configurations, including for lighting applications, monochromatic emitting devices are the mainstream. In monochromatic emitting organic EL devices, multiple layers, such as hole transport layers, emitting layers, and electron transport layers, are typically formed. By adjusting the deposition rate of each layer according to the transport speed, a desired film thickness is formed, thereby manufacturing an organic EL device. Because organic materials are very expensive, it is necessary to minimize the deposition of unwanted areas, requiring a smaller spacing between the masks 7.

[0088] After film formation is completed in the film-forming section 35 and the mask 7 moves to the separating section 36, it needs to be stopped in the next substrate mask separation section 37 for processing, thus increasing the distance between it and the subsequent mask 7. During separation, a position confirmation sensor (not shown) is used. If a certain position is passed, the rotational speed of the transport roller 4 carrying the mask 7 is increased only to increase the distance between it and the subsequent mask. When the distance between it and the subsequent mask has increased, the mask 7 is transported to the substrate mask separation section 37. If there is no workpiece (mask 7) in the substrate mask separation section 37, the mask 7 can be transported to the substrate mask separation section 37 while maintaining the separation speed.

[0089] When the overlapping substrate 6 and mask 7 are transported to the substrate-mask separation section 37, the substrate 6 is lifted by a lifting mechanism provided inside the substrate-mask separation section 37. The lifted substrate 6 is then transported to the substrate transport section 38 by a vacuum transport robot 45 provided in the substrate transport section 38. Regarding the mask 7, if the mask shape detection section 10 determines that the mask shape is within a specified range, it is transported to the mask return section 41 and then sent back to the substrate-mask assembly section 33. Thus, the mask 7 is used again for film formation. On the other hand, if the mask shape detection section 10 determines that the mask shape is outside the specified range, the mask 7 is transported to the mask discharge section 43. The mask 7 is maintained and reused or discarded. In this way, since masks 7 whose shape is outside the specified range due to certain influences are not sent to the transport path for film formation, it is possible to suppress the reduction in film formation accuracy or yield.

[0090] <Manufacturing Methods of Electronic Devices>

[0091] Next, an example of a method for manufacturing an electronic device using the film-forming apparatus of this embodiment will be described. Hereinafter, as an example of an electronic device, the structure of an organic EL display device will be shown, and a method for manufacturing an organic EL display device will be illustrated.

[0092] First, let me explain the manufactured organic EL display device. Figure 7 (a) is an overall view of the organic EL display device 100. Figure 7 (b) represents the cross-sectional structure of a pixel.

[0093] like Figure 7As shown in (a), in the display area 101 of the organic EL display device 100, a plurality of pixels 102, each equipped with a plurality of light-emitting elements, are arranged in a matrix. Each light-emitting element has a structure having an organic layer sandwiched between a pair of electrodes, as will be described in detail later. It should be noted that, as used herein, a pixel refers to the smallest unit in the display area 101 capable of displaying a desired color. In the case of the organic EL display device of this embodiment, the pixel 102 is composed of a combination of a first light-emitting element 102R, a second light-emitting element 102G, and a third light-emitting element 102B that emit different colors from each other. The pixel 102 is mostly composed of a combination of red, green, and blue light-emitting elements, but it may also be a combination of yellow, cyan, and white light-emitting elements, as long as at least one color is used, there is no particular limitation.

[0094] Figure 7 (b) is Figure 7 (a) is a partial cross-sectional view at the SS line. Pixel 102 is composed of multiple light-emitting elements, each of which has a first electrode (anode) 104, a hole transport layer 105, any one of light-emitting layers 106R, 106G, and 106B, an electron transport layer 107, and a second electrode (cathode) 108 on substrate 103. The hole transport layer 105, light-emitting layers 106R, 106G, 106B, and electron transport layer 107 are equivalent to organic layers. Furthermore, in this embodiment, light-emitting layer 106R is an organic EL layer emitting red light, light-emitting layer 106G is an organic EL layer emitting green light, and light-emitting layer 106B is an organic EL layer emitting blue light. Light-emitting layers 106R, 106G, and 106B are respectively formed into patterns corresponding to the light-emitting elements (sometimes referred to as organic EL elements) emitting red, green, and blue light.

[0095] Furthermore, the first electrode 104 is formed separately for each light-emitting element. The hole transport layer 105, the electron transport layer 107, and the second electrode 108 can be formed shared among multiple light-emitting elements 102R, 102G, and 102B, or they can be formed for each light-emitting element. It should be noted that an insulating layer 109 is provided between the first electrode 104 and the second electrode 108 to prevent short circuits due to foreign matter. In addition, since the organic EL layer is susceptible to deterioration due to moisture and oxygen, a protective layer 110 is provided to protect the organic EL element from the effects of moisture and oxygen.

[0096] exist Figure 7In (b), the hole transport layer 105 and the electron transport layer 107 are shown as a single layer, but depending on the structure of the organic EL display element, they can also be formed by multiple layers including a hole blocking layer and an electron blocking layer. Alternatively, a hole injection layer with a band structure capable of smoothly injecting holes from the first electrode 104 to the hole transport layer 105 can be formed between the first electrode 104 and the hole transport layer 105. Similarly, an electron injection layer can also be formed between the second electrode 108 and the electron transport layer 107.

[0097] Next, a specific example of a manufacturing method for an organic EL display device will be explained.

[0098] First, a substrate 103 is prepared having a circuit (not shown) for driving an organic EL display device and a first electrode 104.

[0099] Acrylic resin is spin-coated onto a substrate 103 on which the first electrode 104 is formed. The acrylic resin is then patterned using photolithography to form an opening in the portion where the first electrode 104 is formed, thus forming an insulating layer 109. This opening corresponds to the light-emitting area where the light-emitting element actually emits light.

[0100] A substrate 103 with an insulating layer 109 is fed into a first organic material film-forming apparatus. The substrate is held using a substrate support stage and an electrostatic chuck. A hole transport layer 105 is formed as a common layer on the first electrode 104 of the display area. The hole transport layer 105 is formed by vacuum evaporation. In practice, the hole transport layer 105 is formed to a size larger than the display area 101; therefore, a high-precision mask is not required.

[0101] Next, the substrate 103 to which the hole transport layer 105 is formed is fed into the second organic material film forming apparatus and held by a substrate support stage and an electrostatic chuck. The substrate and the mask are aligned, the substrate is placed on the mask, and a red light emitting layer 106R is formed on the portion of the substrate 103 where the red light emitting element is arranged.

[0102] Similar to the deposition of the light-emitting layer 106R, a green light-emitting layer 106G is deposited using a third organic material film-forming apparatus, and a blue light-emitting layer 106B is deposited using a fourth organic material film-forming apparatus. After the deposition of the light-emitting layers 106R, 106G, and 106B is completed, an electron transport layer 107 is deposited over the entire display area 101 using a fifth film-forming apparatus. The electron transport layer 107 is formed as a common layer on the three-color light-emitting layers 106R, 106G, and 106B.

[0103] The substrate forming the electron transport layer 107 is moved in a metallic vapor deposition material film forming apparatus to form a second electrode 108.

[0104] Thereafter, it is moved to a plasma CVD apparatus to form a protective layer 110, and the organic EL display device 100 is completed.

[0105] From the time when the substrate 103 having the insulating layer 109 patterned thereon is fed into the film forming apparatus until the formation of the protective layer 110 is completed, if it is exposed to an environment containing moisture and oxygen, the light emitting layer made of an organic EL material may deteriorate due to moisture and oxygen. Therefore, in this embodiment, the feeding and discharging of the substrate between the film forming apparatuses are performed in a vacuum environment or an inert gas environment.

[0106] (Others)

[0107] In the above embodiment, a description is given of a case where values related to torque fluctuations for detecting the shape of the mask 7 use the times (dT1, dT2, dT3) from when the torque value of the first conveying roller 4a starts to rise until the torque value of the second conveying roller 4b starts to rise. However, other values may also be used for the values related to torque fluctuations for detecting the shape of the mask 7.

[0108] For example, as the value related to torque fluctuations, at least either the peak value of the torque value of the first conveying roller 4a or the peak value of the torque value of the second conveying roller 4b may be used. That is, as described by referring to Figures 3-5 As described above, by detecting I3, I4 < I1, I2, it is possible to detect that the mask 7 is deformed into a concave shape. Therefore, if I1 - I3 is within a predetermined range (threshold value), the mask shape detection unit 10 can determine that the mask shape is within the specified range, and if it exceeds the predetermined range, the mask shape detection unit 10 can determine that the mask shape is outside the specified range. Similarly, if I2 - I4 is within a predetermined range (threshold value), the mask shape detection unit 10 can determine that the mask shape is within the specified range, and if it exceeds the predetermined range, the mask shape detection unit 10 can determine that the mask shape is outside the specified range.

[0109] In addition, by detecting I5, I6 > I1, I2, it is possible to detect that the mask 7 is deformed into a convex shape. Therefore, if I1 - I5 is within a predetermined range (threshold value), the mask shape detection unit 10 can determine that the mask shape is within the specified range, and if it exceeds the predetermined range, the mask shape detection unit 10 can determine that the mask shape is outside the specified range. Similarly, if I2 - I6 is within a predetermined range (threshold value), the mask shape detection unit 10 can determine that the mask shape is within the specified range, and if it exceeds the predetermined range, the mask shape detection unit 10 can determine that the mask shape is outside the specified range.

[0110] Alternatively, the value related to torque variation can also be the time from the convergence of the torque variation of the first conveyor roller 4a to the convergence of the torque variation of the second conveyor roller 4b. It should be noted that... Figures 3-5 As can be seen from the various graphs, this time is approximately equal to dT1 when the mask 7 used for reference value measurement is used, approximately equal to dT2 when the mask 7 is deformed into a concave shape, and approximately equal to dT3 when the mask 7 is deformed into a convex shape. Therefore, the shape of the mask can be detected by the same comparison as in the above embodiment.

[0111] Furthermore, the value related to torque variation can also be the time from when the torque value of the first conveyor roller 4a reaches its peak to when the torque of the second conveyor roller 4b reaches its peak. It should be noted that... Figures 3-5 As can be seen from the various graphs, this time is approximately equal to dT1 when the mask 7 used for reference value measurement is used, approximately equal to dT2 when the mask 7 is deformed into a concave shape, and approximately equal to dT3 when the mask 7 is deformed into a convex shape. Therefore, the shape of the mask can be detected by the same comparison as in the above embodiment.

[0112] As described above, various values ​​can be used for the torque variation-related values ​​used to detect the shape of the mask 7. Furthermore, in the above embodiment, the mask shape detection unit 10 is shown determining whether the mask shape is within a specified range using only one value; however, a structure using multiple values ​​to determine whether the mask shape is within a specified range can also be adopted. For example, multiple values ​​can be detected to determine whether the mask shape is within or outside a predetermined range; if one value is outside the range, the mask shape is determined to be outside the specified range; or if multiple or all values ​​are outside the range, the mask shape is determined to be outside the specified range.

[0113] Furthermore, if the mask 7 used for measuring reference values ​​is transported periodically and deviates significantly from the reference torque waveforms 20 and 21, it can detect certain malfunctions in the mask transport mechanism. This allows for warnings about the scheduled maintenance period for the mask transport device.

[0114] Furthermore, in the above embodiment, the mask shape detection unit 10 is shown to be disposed in the film forming section 35, but the placement of the mask shape detection unit 10 is not limited to the film forming section 35. For example, it may be disposed at a position downstream of the substrate mask separation section 37.

Claims

1. A mask conveying device, characterized in that, The mask conveying device includes: A first conveyor roller, the first conveyor roller conveys the mask; A second conveying roller further conveys the mask conveyed by the first conveying roller downstream. The detection component uses any one of the following as a value related to torque variation: the time from when the torque value of the first conveyor roller starts to rise until the torque value of the second conveyor roller starts to rise; the time from when the torque value of the first conveyor roller converges until the torque value of the second conveyor roller converges; the peak value of the torque value; and the time from when the torque value of the first conveyor roller reaches its peak value until the torque value of the second conveyor roller reaches its peak value. The detection component detects the value related to torque variation of the first conveyor roller and the value related to torque variation of the second conveyor roller. as well as A mask shape detection component detects the shape of the mask by comparing a value related to torque variation detected by the detection component during the conveying of a flat, non-warped mask with a reference value, comparing a value related to torque variation of the first conveying roller with a reference value of the first conveying roller, and comparing a value related to torque variation of the second conveying roller with a reference value of the second conveying roller.

2. The mask conveying device as described in claim 1, characterized in that, The mask shape detection member detects the shape of the mask by using a reference value as a reference value, which is related to the torque variation of the reference value measurement mask detected by the detection member when the reference value measurement mask is transported as a flat mask without warping.

3. The mask conveying device as described in claim 1 or 2, characterized in that, The mask conveying device includes: A first servo motor, the first servo motor causing the first conveyor roller to rotate; and The second servo motor rotates the second conveyor roller. The detection component detects values ​​related to the torque variation of the first and second conveying rollers based on the current values ​​of the first and second servo motors.

4. The mask conveying device as described in claim 2, characterized in that, The mask conveying device includes a storage component that stores values ​​related to torque variations detected by the detection component. The value detected by the detection component when delivering the reference value measurement mask is stored as the reference value in the storage component, and the mask shape detection component uses the reference value stored in the storage component.

5. The mask conveying device as described in claim 1 or 2, characterized in that, The mask shape detection component uses a value representing the time from when the torque value of the first conveyor roller begins to rise until when the torque value of the second conveyor roller begins to rise in order to detect the mask shape.

6. The mask conveying device as described in claim 1 or 2, characterized in that, The mask shape detection component uses at least one of the peak value of the torque value of the first conveyor roller and the peak value of the torque value of the second conveyor roller to detect the mask shape.

7. The mask conveying device as described in claim 1 or 2, characterized in that, The mask shape detection component uses a value representing the time from the convergence of the torque value of the first conveyor roller to the convergence of the torque value of the second conveyor roller in order to detect the mask shape.

8. The mask conveying device as described in claim 1 or 2, characterized in that, The mask shape detection component uses a value representing the time from when the torque value of the first conveyor roller reaches its peak value to when the torque value of the second conveyor roller reaches its peak value in order to detect the mask shape.

9. The mask conveying device as described in claim 1 or 2, characterized in that, If the difference between the value detected by the detection component and the reference value is within a predetermined range, the mask, after being conveyed by the second conveyor roller, returns to the conveying path conveyed by the first conveyor roller. If the difference between the value detected by the detection component and the reference value exceeds a predetermined range, the mask conveyed by the second conveying roller is conveyed to the outside of the conveying path.

10. A film-forming apparatus, characterized in that, The film-forming apparatus includes: The mask conveying device according to any one of claims 1 to 9; as well as A film-forming component for forming a thin film on a substrate via the mask while the substrate and the mask are overlapped.

11. A mask shape detection method, used to detect the shape of a mask conveyed by the mask conveying device according to any one of claims 1 to 9, characterized in that, The mask shape detection method includes: In the first step, any one of the following is taken as a value related to torque variation: the time from when the torque value of the first conveying roller starts to rise until the torque value of the second conveying roller starts to rise; the time from when the torque value of the first conveying roller converges until the torque value of the second conveying roller converges; the peak value of the torque value; and the time from when the torque value of the first conveying roller reaches its peak value until the torque value of the second conveying roller reaches its peak value. The value related to torque variation of the first conveying roller when the mask is conveyed by the first conveying roller is detected by the detection component. The second step involves detecting, by the detection component, a value related to the torque variation of the second conveyor roller as the mask, conveyed by the first conveyor roller, is further conveyed downstream by the second conveyor roller; and In the third step, the shape of the mask is detected by comparing the value related to torque variation detected by the detection member when conveying a flat mask without warping with the reference value of the first conveyor roller detected in the first step with the reference value of the first conveyor roller, and by comparing the value related to torque variation detected in the second step with the reference value of the second conveyor roller.

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