Mask transfer device, film forming apparatus, and mask shape detection method

Abstract

To provide a mask transporting device that can detect change in mask shape, and to provide a film deposition apparatus and a method for detecting a mask shape.SOLUTION: A mask transporting device includes: a first transporting roller 4a for transporting a mask 7; a second transporting roller 4b for transporting further downstream the mask 7 transported by the first transporting roller 4a; detection means for detecting a value relating to variation in torques of the first transporting roller 4a and the second transporting roller 4b; and mask shape detection means for detecting a shape of the mask 7 on the basis of a value detected by the detection means.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a mask transfer device, a film forming device, and a mask shape detection method for a mask that is superimposed on a substrate when forming a film on the substrate.

Background Art

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

[0003] As an apparatus for manufacturing an organic EL display, an in-line type apparatus that forms a film while transporting the substrate and the mask in a superimposed state is known. In this in-line type apparatus, the film forming process is configured to be continuous after the positioning process of the substrate and the mask. After the substrate and the mask are positioned, they are transported into a film forming chamber, and film formation is performed while being transported. Generally, when manufacturing an organic EL display, a thin plate such as glass or resin is often used as the substrate, and when the size of the substrate increases, the deflection when the substrate is held horizontally increases. Therefore, since it is difficult to transport the substrate alone, a substrate carrier for holding the substrate is usually used.

[0004] In the in-line type apparatus configured as described above, the substrate before film formation is loaded into the apparatus and held by the substrate carrier. Then, after the substrate and the mask are aligned (positioned) and superimposed, film formation is performed while being transported. And only the substrate on which the film has been formed is sent to the subsequent process, and the substrate carrier and the mask are returned upstream and used again for film formation. Thus, in the in-line type apparatus, it is common for the substrate carrier and the mask to continuously circulate in the manufacturing line.

[0005] In such a configuration, since the mask and the substrate carrier circulate within the manufacturing line, they are heated every time a film deposition process is performed. When the inside of the chamber is in a vacuum during the process of returning the mask and the substrate carrier upstream, it is difficult for heat to escape. Therefore, the temperature of the substrate carrier and the mask increases with each cycle because the next film deposition starts before the accumulated heat completely dissipates. Depending on the manufacturing conditions, the next film deposition may be performed with the temperature being 60°C or higher than before the cycle. For example, the substrate size of G8 is 2200×2500 mm, and the corresponding mask and substrate carrier are approximately 3000 mm in both length and width. In that case, the amount of thermal expansion is 3 mm or more when the material is SUS and 4 mm or more when the material is aluminum, resulting in a change in the shape of the mask.

[0006] Therefore, in the case of the in-line type of apparatus as described above, generally, after a predetermined number of film depositions are performed, the mask is taken out of the manufacturing line for maintenance to improve the yield. For example, a control system is incorporated in a computer that manages the entire apparatus, where individual IDs are assigned to all the masks input to the apparatus, the conveyance status is monitored, thresholds are set based on the conveyance path length and the number of film depositions, and when the thresholds are reached, the mask is taken out of the apparatus.

[0007] However, when a change in shape occurs due to an unexpected disturbance such as the mask colliding with another mask in addition to thermal expansion, the above method cannot detect the shape of the mask. Therefore, if a mask with a changed shape is used, even if the positioning between the mask and the substrate is performed over time, a deviation may occur during conveyance, leading to a decrease in the yield.

[0008] Note that in the technology disclosed in Patent Document 1, mechanical deterioration of the roller conveyance unit can be determined, but the shape of the mask cannot be detected.

Prior Art Documents

Patent Documents

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-311259 [Summary of the Invention] [Problems to be Solved by the Invention]

[0010] As described above, in the conventional apparatus, even if the shape of the mask to be transported changes due to some influence, it may be used as it is, which may cause adverse effects. For example, the film formation accuracy may decrease, or the yield may decrease.

[0011] An object of the present invention is to provide a mask transport apparatus, a film forming apparatus, and a mask shape detection method capable of detecting a mask shape. [Means for Solving the Problems]

[0012] The present invention employs the following means to solve the above problems. That is, the mask transport apparatus of the present invention a first transport roller for transporting a mask, a second transport roller for further transporting the mask transported by the first transport roller to the downstream side, The time until the torque of the conveying roller begins to increase, the time until the torque variation converges, the peak of the torque value, and the time until the torque reaches the peak, any of which is used as a value related to the torque variation the first transport roller the value related to the torque variation and the second transport roller the detection means for detecting a value related to torque fluctuation, Based on the value related to the torque variation detected by the detection means when the flat mask without warping is conveyed, the value related to the torque variation of the first conveying roller is compared with the reference value of the first conveying roller, and the value related to the torque variation of the second conveying roller is compared with the reference value of the second conveying roller, thereby mask shape detection means for detecting the shape of the mask based on the value detected by the detection means, related to the torque variation and is characterized by comprising the same. [Effects of the Invention]

[0013] As described above, according to the present invention, the mask shape can be detected. [Brief Description of the Drawings]

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

[0015] Hereinafter, with reference to the drawings, embodiments for carrying out the present invention will be exemplarily and specifically described based on examples. However, dimensions, materials, shapes, relative arrangements, etc. of the components described in this example are not intended to limit the scope of the present invention only to those, unless otherwise specifically described.

[0016] (Example) With reference to FIGS. 1 to 7, a mask transfer device for a mask 7 on which a substrate 6 is superposed when forming a film on the substrate, a film forming apparatus including the mask transfer device, and a mask shape detection method will be described. The film forming apparatus according to this example is an in-line type film forming apparatus that performs a film forming process while transporting the substrate 6 and the mask 7 in a positioned state, and is applied, for example, as an apparatus for manufacturing an organic EL display. This film forming apparatus is provided with a mask transfer device for transferring the mask 7.

[0017] [Outline of Mask Transfer Device] Hereinafter, with particular reference to FIGS. 1 and 6, the outline of the mask transfer device will be described. FIG. 1 is a top schematic view showing an example of the mask transfer device provided in the film forming apparatus according to this example. FIG. 6 shows an outline of the in-line type film forming apparatus according to this example.

[0018] In this embodiment, for example, a substrate 6 made of non-alkali glass with a size (specifically 2500 mm × 2200 mm × 0.5 mm) called the eighth generation is preferably used. However, the material and dimensions of the substrate applicable in the present invention are not particularly limited. The substrate 6 is placed on the mask 7. When the above-mentioned eighth-generation substrate 6 is applied, for example, a mask 7 with a size of 2900 mm × 2500 mm × 50 mm is preferably used. On the substrate 6, a TFT circuit is formed if it is an organic EL display, and electrodes are formed if it is an organic EL lighting.

[0019] As shown in FIG. 6, the substrate 6 is introduced into the substrate loading unit 31. Thereafter, in the substrate loading unit 31, a decompression process is performed from atmospheric pressure to a predetermined pressure by a vacuum pump (not shown). For example, the decompression process is performed until it reaches 5.0×10 -4 Pa or less. After the decompression process in the substrate loading unit 31, an openable and closable plate-like valve called a gate valve between the substrate loading unit 31 and the substrate transfer unit 32 opens. At this time, the pressure in the substrate transfer unit 32 is set to be lower than that in the substrate loading unit 31 (for example, set to a pressure of 1.0×10 -4 Pa or less). When the substrate 6 is transferred to a predetermined position in the substrate transfer unit 32, the gate valve between the substrate loading unit 31 and the substrate transfer unit 32 is closed. Thereafter, the substrate 6 is transferred from the substrate transfer unit 32 to the substrate-mask combination unit 33.

[0020] In the substrate-mask combination unit 33, an alignment operation 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 centered and then combined within the substrate-mask combination unit 33, but marks for alignment may be provided on the substrate 6 and the mask 7 to perform an alignment operation by image processing.

[0021] With the substrate 6 placed on the mask 7, they are conveyed by a plurality of conveying rollers 4 in the order of the substrate-mask combined part 33, the trailing part 34, the film-forming part 35 as the film-forming means, the separating part 36, and the substrate-mask separating part 37. In the mask conveying device according to the present embodiment, a pair of conveying rollers 4 provided on both sides in the direction perpendicular to the conveying direction A of the mask 7 is taken as a set, and a plurality of sets of conveying rollers 4 are provided along the conveying direction A. These conveying rollers 4 are respectively connected to the magnetic seal 3 and are connected to the servo motor 1 via the coupling 2 arranged outside the chamber configured to have a vacuum atmosphere inside. As shown in FIG. 1, it is desirable that each conveying roller 4 be connected to an individual servo motor 1. A controller (not shown) for controlling the plurality of servo motors 1 controls the plurality of conveying rollers 4 to rotate synchronously. Although the plurality of servo motors 1 are synchronously controlled to convey the mask 7, the mask 7 may meander due to mechanical assembly accuracy or the like. Therefore, in the mask conveying device according to the present embodiment, in order to suppress the meandering of the mask 7, side rollers 5 are respectively provided between the conveying rollers 4 adjacent to each other in the conveying direction A.

[0022] And in the present embodiment, a mask shape detection part 10 as mask shape detection means is provided in the film-forming part 35. In this mask shape detection part 10, when the mask shape is detected within the specified range after the substrate 6 and the mask 7 are separated in the substrate-mask separating part 37, the mask 7 is sent back to the substrate-mask combined part 33 again by the mask return part 41. That is, the mask 7 is returned to the conveying path for film formation. Also, in the mask shape detection part 10, when the mask shape is detected outside the specified range, after the substrate 6 and the mask 7 are separated in the substrate-mask separating part 37, the mask 7 is conveyed to the mask discharge part 43. That is, the mask 7 is conveyed outside the conveying path for film formation.

[0023] Here, in the mask transfer device according to this embodiment, among the plurality of transfer rollers 4, a first transfer roller 4a used for detecting the mask shape and a second transfer roller 4b for further transferring the mask 7 conveyed by the first transfer roller 4a to the downstream side are provided. In the mask shape detection unit 10, the shape of the mask 7 is detected by using detection means for detecting a value related to the torque fluctuation of the first transfer roller 4a and the second transfer roller 4b. Note that the detection means detects a value related to the torque fluctuation of these transfer rollers from the drive torque of the first servo motor 1a that rotates the first transfer roller 4a and the drive torque of the second servo motor 1b that rotates the second transfer roller 4b.

[0024] <Mask shape detection unit> In particular, with reference to FIG. 2, the mask shape detection unit 10 will be described in more detail. FIG. 2 shows a block diagram of 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, in order to control the first servo motor 1a and the second servo motor 1b for detecting the mask shape, a speed command is transmitted to the motion controller 12. The motion controller 12 transmits the previously set 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, by returning the encoder signals of these servo motors to the motion controller 12 as speed FB (feedback), the first servo motor 1a and the second servo motor 1b rotate at a constant speed. When the mask 7 passes through the first conveying roller 4a and the second conveying roller 4b rotated by the first servo motor 1a and the second servo motor 1b rotating at a constant speed, due to the weight and shape of the mask 7, the load acting on each servo motor changes. Even when the load changes in this way, in order to keep the speed of each servo motor constant, the torque value of each servo motor is controlled. The value related to the torque fluctuation at this time is detected by the control unit 11 which also functions as a detection means, and the control unit 11 detects the shape of the mask 7 by comparing the detected value with a reference value related to the torque fluctuation. Note that the speed by the above speed command can be, for example, 40 mm / second. Of course, this speed may be set appropriately according to the dimensions of various members and the like.

[0025] <Mask Shape Detection Method> In particular, with reference to FIGS. 3 to 5, the mask shape detection method according to this embodiment will be described. In this embodiment, first, when the control unit 11 conveys the mask 7 by the first conveying roller 4a, the control unit 11 detects a value related to the torque fluctuation of the first conveying roller 4a from the torque value of the first servo motor 1a (first step). Next, when the control unit 11 conveys the mask 7 conveyed by the first conveying roller 4a further downstream by the second conveying roller 4b, the control unit 11 detects a value related to the torque fluctuation of the second conveying roller 4b from the torque value of the second servo motor 1b (second step). Then, the mask shape detection unit 10 detects the shape of the mask 7 by comparing the values detected in the first step and the second step with a reference value (third step). Hereinafter, a specific method for detecting the shape of the mask 7 will be described. Note that instead of the torque value, a current value corresponding to the torque value may be acquired.

[0026] <<Reference value>> The control unit 11 includes storage means (such as a ROM or a RAM) for storing the value related to the torque fluctuation detected by the control unit 11. When the value detected by the control unit 11 when the reference value measurement mask is conveyed is stored in the storage means as a reference value, the mask shape detection unit 10 uses the reference value stored in the storage means to detect the shape of the mask 7. Note that the reference value measurement mask is a flat mask without warping. That is, this reference value measurement mask is a mask whose mask shape is guaranteed within a specified range and is a mask for acquiring a torque waveform used as a reference during mask shape detection. (ROM, RAM, etc.). When the value detected by the control unit 11 when the reference value measurement mask is conveyed is stored in the storage means as a reference value, the mask shape detection unit 10 uses the reference value stored in the storage means to detect the shape of the mask 7. The reference value measurement mask is a flat mask without warping. That is, this reference value measurement mask is a mask whose mask shape is guaranteed within a specified range and is a mask for acquiring a torque waveform used as a reference during mask shape detection.

[0027] FIG. 3 is a diagram for explaining the fluctuations in the torque values of the first servo motor 1a and the second servo motor 1b when the reference value measurement mask 7 is conveyed by the first conveying roller 4a and the second conveying roller 4b. The left side of the figure shows how the mask 7 is conveyed, and the right side of the figure shows a waveform representing the torque value fluctuation. In the figure, for the graph on the right side, the horizontal axis represents time and the vertical axis represents the torque value.

[0028] FIG. 3(a) is a diagram for explaining the variation in torque value when the mask 7 for reference value measurement is conveyed by the first conveying roller 4a. When the mask 7 is placed on the first conveying roller 4a, a load is applied to the first servo motor 1a and the speed tends to decrease. Therefore, as described above, the torque value of the first servo motor 1a increases so as to keep the rotational speed of the first conveying roller 4a constant, and then gradually decreases.

[0029] FIG. 3(b) is a diagram for explaining the variation in torque value when the mask 7 for reference value measurement is conveyed by the second conveying roller 4b. The waveform 20 showing the variation in torque value of the first servo motor 1a is also shown in the graph on the right side. As shown in the figure, it can be seen that the waveform 20 showing the variation in torque value of the first servo motor 1a and the waveform 21 showing the variation in torque value of the second servo motor 1b have the same shape.

[0030] In the waveform 20 showing the variation in torque value of the first servo motor 1a, let the torque value when the torque value reaches the peak be I1, and the time from when the torque value starts to rise until it converges be T1. Also, in the waveform 21 showing the variation in torque value of the second servo motor 1b, let the torque value when the torque value reaches the peak be I2, and the time from when the torque value starts to rise until it converges be T2. Further, let the time from when the torque value starts to rise in the waveform 20 until the torque value starts to rise in the waveform 21 be dT1.

[0031] In order to detect the shape of the mask 7, some of the values related to the torque variation can be used. In this embodiment, the case of using the time from when the torque value of the first conveying roller 4a (corresponding to the torque value of the first servo motor 1a) starts to rise until the torque value of the second conveying roller 4b (corresponding to the torque value of the second servo motor 1b) starts to rise is shown. In this case, the above time dT1 is stored in the storage unit provided in the control unit 11.

[0032] Even when the mask 7 used for film formation is being conveyed, fluctuations in the torque values of the first servo motor 1a and the second servo motor 1b are detected in the same manner as when the mask 7 for reference value measurement is being conveyed. Then, the time from when the torque value of the first conveying roller 4a starts to increase until the torque value of the second conveying roller 4b starts to increase and the time dT1 are compared by the control unit 11. If the difference is within a predetermined range (threshold value), the mask shape detection unit 10 determines that the mask shape is within the specified range. On the other hand, if the above difference exceeds the predetermined range, the mask shape detection unit 10 determines that the mask shape is outside the specified range.

[0033] <<In the case of a mask deformed into a concave shape>> FIG. 4 is a diagram for explaining fluctuations in the torque values of the first servo motor 1a and the second servo motor 1b when the mask 7 deformed into a concave shape is conveyed by the first conveying roller 4a and the second conveying roller 4b. The left side of the figure shows how the mask 7 is conveyed, and the right side of the figure shows a waveform representing the fluctuation of the torque value. In the figure, for the graph on the right side, the horizontal axis represents time and the vertical axis represents the torque value. The movement is shown. In the figure, for the graph on the right side, the horizontal axis represents time and the vertical axis represents the torque value.

[0034] FIG. 4(a) is a diagram for explaining fluctuations in the 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 side, a waveform 22 showing the fluctuation of the torque value of the first servo motor 1a when conveying this mask 7 is shown by a solid line, and the above waveform 20 is shown by a dotted line.

[0035] FIG. 4(b) is a diagram for explaining fluctuations in the 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 side, a waveform 23 showing the fluctuation of the torque value of the second servo motor 1b when conveying this mask 7 and the above waveform 22 are shown by solid lines, and the above waveforms 20 and 21 are shown by dotted lines.

[0036] In the waveform 22 showing the variation of the torque value of the first servo motor 1a, let the torque value when the torque value reaches the peak be I3, and let the time from when the torque value starts to rise until it converges be T3. Also, in the waveform 23 showing the variation of the torque value of the second servo motor 1b, let the torque value when the torque value reaches the peak be I4, and let the time from when the torque value starts to rise until it converges be T4. Further, let the time from when the torque value starts to rise in waveform 22 until the torque value starts to rise in waveform 23 be dT2.

[0037] From the graph, it can be seen that I3, I4 < I1, I2 and dT1 < dT2. That is, by detecting that I3, I4 < I1, I2 or dT1 < dT2, it is possible to detect that the mask 7 is deformed into a concave shape. And in this embodiment, if dT2 - dT1 is within a predetermined range (threshold value), the mask shape detection unit 10 determines that the mask shape is within the specified range. On the other hand, if dT2 - dT1 exceeds the predetermined range, the mask shape detection unit 10 determines that the mask shape is outside the specified range.

[0038] <<In the case of a mask deformed into a convex shape>> FIG. 5 is a diagram for explaining 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 left side of the figure shows how the mask 7 is conveyed, and the right side of the figure shows the waveform representing the variation of the torque value. In the figure, for the graph on the right side, the horizontal axis is time and the vertical axis is the torque value.

[0039] FIG. 5(a) is a diagram for explaining 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 showing the variation of the torque value of the first servo motor 1a when conveying this mask 7 is shown by a solid line, and the above-mentioned waveform 20 is shown by a dotted line.

[0040] FIG. 5(b) is a diagram for explaining the variation in 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 waveform 25 showing the variation in torque value of the second servo motor 1b when conveying this mask 7 and the above waveform 24 are shown by solid lines, and the above waveforms 20 and 21 are shown by dotted lines.

[0041] In the waveform 24 showing the variation in torque value of the first servo motor 1a, let the torque value when the torque value reaches the peak be I5, and the time from when the torque value starts to rise until it converges be T5. Also, in the waveform 25 showing the variation in torque value of the second servo motor 1b, let the torque value when the torque value reaches the peak be I6, and the time from when the torque value starts to rise until it converges be T6. Further, in the waveform 24, from when the torque value starts to rise Let the time until the torque value starts to rise in the waveform 25 be dT3.

[0042] From the graph, it can be seen that I5, I6 > I1, I2 and dT1 > dT3. That is, by detecting that I5, I6 > I1, I2 or dT1 > dT3, it is possible to detect that the mask 7 is deformed into a convex shape. And in this embodiment, if dT3 - dT1 is within a predetermined range (threshold value), the mask shape detection unit 10 determines that the mask shape is within the specified range. On the other hand, when dT3 - dT1 exceeds the predetermined range, the mask shape detection unit 10 determines that the mask shape is outside the specified range. The reason for I5, I6 > I1, I2 is due to the impact generated when the tip of the mask 7 hits before reaching the uppermost part of the conveying roller 4.

[0043] <Film forming apparatus> Referring to FIG. 6, the inline film forming apparatus will be described in more detail. When film formation is performed, the substrate 6 is introduced from the substrate introduction unit 31. The substrate 6 is introduced into the substrate introduction unit 31 with the lower surface serving as the film formation surface. In the substrate introduction unit 31, the pressure is reduced by a vacuum pump (not shown) connected to the substrate introduction unit 31 until it reaches a predetermined pressure or lower. Since less time is required for evacuation when the chamber internal volume of the substrate introduction unit 31 is smaller, it is better to perform the operation of orienting the film formation surface of the substrate 6 downward at a stage prior to the substrate introduction unit 31.

[0044] When the evacuation is performed in the substrate introduction unit 31 until the pressure reaches a predetermined pressure or lower, the substrate 6 is transported by the vacuum transfer robot 44 installed in the substrate transfer unit 32. Specifically, the vacuum transfer robot 44 performs the transfer by receiving the substrate 6 introduced into the substrate introduction unit 31. An openable and closable plate-like valve provided between the substrate introduction unit 31 and the substrate transfer unit 32 opens. Then, the vacuum transfer robot 44 turns so as to face the substrate introduction unit 31, extends its arm to the lower surface of the substrate 6 placed in the substrate introduction unit 31, and then picks up the substrate 6. The vacuum transfer robot 44 that has received the substrate 6 pulls the substrate 6 into the substrate transfer unit 32. When the substrate 6 is pulled into the substrate transfer unit 32 and reaches a predetermined position, the openable and closable plate-like valve provided between the substrate introduction unit 31 and the substrate transfer unit 32 closes. The substrate transfer unit 32 may be provided with a buffer unit for stocking the substrate 6 as needed and a pre-treatment unit for activating the film formation surface of the substrate 6.

[0045] Next, the vacuum transfer robot 44 passes the substrate 6 pulled into the substrate transfer unit 32 to the substrate mask combination unit 33. At that time, the mask 7 has been previously introduced into the substrate mask combination unit 33 from the mask return unit 41 or the mask introduction unit 40. Then, an openable and closable plate-like valve provided between the substrate transfer unit 32 and the substrate mask combination unit 33 opens. After that, the vacuum transfer robot 44 turns so as to face the substrate mask combination unit 33 and passes the substrate 6 to a substrate receiver (not shown) provided in the substrate mask combination unit 33. Then, the vacuum transfer robot 44 returns to a predetermined position within the substrate transfer unit 32, and the openable and closable plate-like valve provided between the substrate transfer unit 32 and the substrate mask combination unit 33 closes.

[0046] The substrate 6 passed to the substrate holder of the substrate-mask combining part 33 is placed on the mask 7. At this time, it is preferable to execute an alignment process by an alignment mechanism that aligns the substrate 6 and the mask 7. Further, it is more preferable to place a member for enhancing the adhesion between the mask 7 and the substrate 6 on the substrate 6 placed on the mask 7. Specifically, it is preferable to place a member using a magnet or a member having a mechanism for adjusting the shape of the substrate.

[0047] After the mask 7 and the substrate 6 are overlapped in the substrate-mask combining part 33, they are conveyed to the chasing part 34 in the overlapped state. The mask transfer device is provided from the substrate-mask combining part 33. Thereby, the mask 7 is conveyed together with the substrate 6 by a plurality of transfer rollers 4 that contact the lower surface of the mask 7 with the substrate 6 overlapped. In the chasing part 34, an operation is performed to narrow the interval between the mask 7 combined with the preceding substrate 6. Specifically, , in a state where the preceding mask 7 is being conveyed at the film formation speed, the interval can be narrowed by conveying the subsequent mask 7 at a speed equal to or higher than the film formation speed. Thereafter, by conveying the subsequent mask 7 at the film formation speed, a desired interval can be obtained. The smaller the interval, the less waste of the film forming material, so it is preferable that there is no interval between the masks. However, if the masks come into contact with each other, it will cause particles and the like, so it is preferable to ensure a minimum interval.

[0048] In the chasing part 34, while maintaining the state where the interval between the masks is narrowed, the overlapped mask 7 and substrate 6 are conveyed to the film forming part 35. During the conveyance, the posture of the mask 7 is detected, and film formation is performed on the substrate 6 while posture control is performed.

[0049] In the film forming section 35, a film forming source (not shown) is installed. Note that, for the film forming source, in the case of vacuum evaporation, an evaporation source is provided; in the case of sputtering, a target is provided; and in the case of CVD, an electrode and a flow path for the film forming gas are provided. In this embodiment, the case of vacuum evaporation is taken as an example, but for sputtering and CVD, the attitude control and conveyance control of the mask 7 are the same.

[0050] In the film forming section 35, generally, a plurality of layers of films are formed on the substrate 6. The evaporation source as the film forming source is fixed, and while moving the stacked mask 7 and the substrate 6, a desired film is deposited on the substrate 6 to form a thin film. For a single-color organic EL device, a mask 7 having an opening in the light emitting area is used. For a multi-color organic EL device, a mask 7 having an opening in the area where film formation is desired for each color is used. In the in-line method, single-color light emitting devices including for lighting applications are the mainstream. Also in a single-color organic EL device, generally, film formation of a plurality of layers such as a hole transport layer, a light emitting layer, and an electron transport layer is performed. By adjusting the film formation rate of each layer according to the conveyance speed and forming a desired film with a desired film thickness, an organic EL device is manufactured. Since organic materials are very expensive, it is required to narrow the interval of the mask 7 in order to minimize film formation on unnecessary portions.

[0051] When film formation is completed in the film forming section 35 and the mask 7 moves to the separation section 36, it is necessary to stop the movement of the mask 7 and perform processing in the subsequent substrate-mask separation section 37, so the distance from the subsequent mask 7 is widened. At the time of separation, when a certain position is passed by a position confirmation sensor (not shown), only the rotation speed of the conveyance roller 4 on which the mask 7 rides is increased to widen the distance from the subsequent mask. When the distance from the subsequent mask is widened, the mask 7 is conveyed 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 conveyed to the substrate-mask separation section 37 at the separation speed.

[0052] When the substrate 6 and the mask 7 in the stacked state are conveyed to the substrate-mask separation unit 37, the substrate 6 is lifted by a lifting mechanism provided inside the substrate-mask separation unit 37. The lifted substrate 6 is conveyed to the substrate conveyance unit 38 by a vacuum conveyance robot 45 installed in the substrate conveyance unit 38. Regarding the mask 7, when it is determined by the above-described mask shape detection unit 10 that the mask shape is within the specified range, it is conveyed to the mask return unit 41 and sent back to the substrate-mask combination unit 33 again. As a result, the mask 7 is used for film formation again. On the other hand, when it is determined by the above-described mask shape detection unit 10 that the mask shape is outside the specified range, the mask 7 is conveyed to the mask discharge unit 43. This mask 7 is maintained and reused or discarded. In this way, since the mask 7 whose shape is outside the specified range due to some influence is not sent to the conveyance path for film formation, it is possible to suppress a decrease in film formation accuracy or a decrease in yield.

[0053] <Method for manufacturing an electronic device> Next, an example of a method for manufacturing an electronic device using the film forming apparatus of this embodiment will be described. Hereinafter, the configuration of an organic EL display device will be shown as an example of an electronic device, and the method for manufacturing the organic EL display device will be Illustrated.

[0054] First, the organic EL display device to be manufactured will be described. FIG. 7(a) is an overall view of the organic EL display device 100, and FIG. 7(b) shows the cross-sectional structure of one pixel.

[0055] As shown in FIG. 7(a), in the display region 101 of the organic EL display device 100, a plurality of pixels 102 each including a light-emitting element are arranged in a matrix. Although details will be described later, each light-emitting element has a structure including an organic layer sandwiched between a pair of electrodes. Here, the pixel refers to the minimum unit capable of displaying a desired color in the display region 101. In the case of the organic EL display device according to 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 exhibit different emissions. The pixel 102 is often composed of a combination of a red light-emitting element, a green light-emitting element, and a blue light-emitting element, but may also be composed of a combination of a yellow light-emitting element, a cyan light-emitting element, and a white light-emitting element, and is not particularly limited as long as it is at least one color or more.

[0056] FIG. 7(b) is a partial cross-sectional schematic view taken along the line S-S of FIG. 7(a). The pixel 102 is composed of a plurality of light-emitting elements, and each light-emitting element has, on the substrate 103, a first electrode (anode) 104, a hole transport layer 105, one of light-emitting layers 106R, 106G, 106B, an electron transport layer 107, and a second electrode (cathode) 108. Among these, the hole transport layer 105, the light-emitting layers 106R, 106G, 106B, and the electron transport layer 107 correspond to the organic layer. Further, in this embodiment, the light-emitting layer 106R is an organic EL layer that emits red light, the light-emitting layer 106G is an organic EL layer that emits green light, and the light-emitting layer 106B is an organic EL layer that emits blue light. The light-emitting layers 106R, 106G, 106B are formed in patterns corresponding to light-emitting elements (sometimes referred to as organic EL elements) that emit red, green, and blue light, respectively.

[0057] Further, 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 may be formed commonly for a plurality of light-emitting elements 102R, 102G, and 102B, or may be formed for each light-emitting element. Note that, in order to prevent short circuits between the first electrode 104 and the second electrode 108 due to foreign matter, an insulating layer 109 is provided between the first electrodes 104. Further, since the organic EL layer deteriorates due to moisture and oxygen, a protective layer 110 for protecting the organic EL element from moisture and oxygen is provided.

[0058] In FIG. 7(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 may be formed of a plurality of layers including a hole blocking layer and an electron blocking layer. Further, a hole injection layer having an energy band structure that can smoothly inject 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.

[0059] Next, an example of a method for manufacturing an organic EL display device will be specifically described.

[0060] First, a substrate 103 on which a circuit (not shown) for driving the organic EL display device and the first electrode 104 are formed is prepared.

[0061] An acrylic resin is spin-coated on the substrate 103 on which the first electrode 104 is formed, and the acrylic resin is patterned by a lithography method so that an opening is formed in the portion where the first electrode 104 is formed to form the insulating layer 109. This opening corresponds to the light-emitting region where the light-emitting element actually emits light.

[0062] The substrate 103 on which the insulating layer 109 is patterned is carried into a first organic material film-forming apparatus, and the base The substrate is held by a substrate support stage and an electrostatic chuck, and the hole transport layer 105 is formed as a common layer on the first electrode 104 in the display region. The hole transport layer 105 is formed by vacuum evaporation. Actually, since the hole transport layer 105 is formed to be larger in size than the display region 101, a high-definition mask is not required.

[0063] Next, the substrate 103 on which the hole transport layer 105 has been formed is carried into a second organic material film forming apparatus and held by a substrate support stage and an electrostatic chuck. Alignment between the substrate and the mask is performed, the substrate is placed on the mask, and an emission layer 106R that emits red light is formed on the portion where the red light-emitting elements of the substrate 103 are arranged.

[0064] Similar to the formation of the emission layer 106R, an emission layer 106G that emits green light is formed by a third organic material film forming apparatus, and further, an emission layer 106B that emits blue light is formed by a fourth organic material film forming apparatus. After the formation of the emission layers 106R, 106G, and 106B is completed, an electron transport layer 107 is formed over the entire display region 101 by a fifth film forming apparatus. The electron transport layer 107 is formed as a common layer for the three-color emission layers 106R, 106G, and 106B.

[0065] The substrate on which the electron transport layer 107 has been formed is moved to a metallic vapor deposition material film forming apparatus to form the second electrode 108.

[0066] Thereafter, it is moved to a plasma CVD apparatus to form a protective layer 110, and the organic EL display device 100 is completed.

[0067] If the substrate 103 on which the insulating layer 109 has been patterned is exposed to an atmosphere containing moisture or oxygen from when it is carried into the film forming apparatus until the formation of the protective layer 110 is completed, the emission layer made of the organic EL material may be deteriorated by moisture or oxygen. Therefore, in this embodiment, the loading and unloading of the substrate between the film forming apparatuses are performed under a vacuum atmosphere or an inert gas atmosphere.

[0068] (Others) In the above-described embodiment, the value related to the torque fluctuation for detecting the shape of the mask 7 shows the case where the time (dT1, dT2, dT3) from when the torque value of the first conveying roller 4a starts to increase until the torque value of the second conveying roller 4b starts to increase is used. However, as for the value related to the torque fluctuation for detecting the shape of the mask 7, other values may be used.

[0069] For example, as the value related to the torque fluctuation, at least either one of the peak value of the torque value of the first conveying roller 4a and the peak value of the torque value of the second conveying roller 4b can also be used. That is, as described with reference to FIGS. 3 to 5, by detecting that 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 determines 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 determines 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.

[0070] Also, by detecting that 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 determines that the mask shape is within the specified range, and if it exceeds the predetermined range, the mask shape detection unit 10 determines 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 determines 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. can be determined. Similarly, if I2 - I6 is within a predetermined range (threshold value), the mask shape detection unit 10 determines 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.

[0071] In addition, as the value related to torque fluctuation, the time from when the torque value fluctuation of the first conveying roller 4a converges until the torque value fluctuation of the second conveying roller 4b converges can also be used. Note that this time is approximately equal to the above dT1 in the case of the mask 7 for reference value measurement, approximately equal to the above dT2 in the case of the mask 7 deformed into a concave shape, and approximately equal to the above dT3 in the case of the mask 7 deformed into a convex shape, as can be understood from each graph in FIGS. 3 to 5. Therefore, the shape of the mask can be detected by comparison similar to the above-described embodiment.

[0072] Furthermore, as the value related to torque fluctuation, the time from when the torque value of the first conveying roller 4a reaches a peak until the torque of the second conveying roller 4b reaches a peak value can also be used. Note that this time is approximately equal to the above dT1 in the case of the mask 7 for reference value measurement, approximately equal to the above dT2 in the case of the mask 7 deformed into a concave shape, and approximately equal to the above dT3 in the case of the mask 7 deformed into a convex shape, as can be understood from each graph in FIGS. 3 to 5. Therefore, the shape of the mask can be detected by comparison similar to the above-described embodiment.

[0073] As described above, regarding the value related to torque fluctuation for detecting the shape of the mask 7, various values can be used. In the above-described embodiment, the mask shape detection unit 10 shows the case of determining whether the mask shape is within a specified range using only one value, but a configuration may also be adopted in which whether the mask shape is within a specified range is determined using a plurality of values. For example, it is also possible to detect whether each of the plurality of values is within a predetermined range or outside the range, and determine that the mask shape is outside the specified range if even one is outside the range, or determine that the mask shape is outside the specified range if a plurality or all of them are outside the range.

[0074] In addition, the mask 7 for reference value measurement is periodically conveyed and compared with the reference torque waveforms 20 and 21. If there is a large deviation from these waveforms, it can be detected that some problem has occurred in the mask conveying mechanism unit. By doing so, it is possible to warn the timing of periodic maintenance of the mask conveying device.

[0075] In addition, in the above-described embodiment, the case where the mask shape detection unit 10 is arranged in the film forming unit 35 is shown, but the arrangement position of the mask shape detection unit 10 is not limited to the film forming unit 35. For example, it can also be provided on the downstream side of the substrate mask separation unit 37.

Explanation of Signs

[0076] 1 Servo motor 1a First servo motor 1b Second servo motor 4 Conveyor roller 4a First conveyor roller 4b Second conveyor roller 6 Substrate 7 Mask 10 Mask shape detection unit 11 Control unit 33 Substrate mask combination unit 35 Film forming unit

Claims

1. A first conveying roller for conveying a mask, A second conveying roller for further conveying the mask conveyed by the first conveying roller to a downstream side, Taking any one of the time until the torque of the conveying roller starts to increase, the time until the torque fluctuation converges, the peak of the torque value, and the time until the torque reaches the peak as a value related to the torque fluctuation, detecting means for detecting the value related to the torque fluctuation of the first conveying roller and the value related to the torque fluctuation of the second conveying roller, Based on the value related to the torque fluctuation detected by the detecting means when a flat mask without warpage is conveyed, comparing the value related to the torque fluctuation of the first conveying roller with the reference value of the first conveying roller, and comparing the value related to the torque fluctuation of the second conveying roller with the reference value of the second conveying roller, mask shape detecting means for detecting the shape of the mask based on the value related to the torque fluctuation detected by the detecting means, A mask conveying device characterized by comprising the same.

2. The mask shape detecting means detects the shape of the mask by using, as the reference value, the value related to the torque fluctuation of the reference value measuring mask detected by the detecting means when the reference value measuring mask as a flat mask without warpage is conveyed. The mask conveying device according to claim 1, characterized by the above.

3. A first servo motor for rotating the first conveying roller, A second servo motor for rotating the second conveying roller, Comprising, The detecting means detects the value related to the torque fluctuation of the first conveying roller and the second conveying roller from the current value of the first servo motor and the current value of the second servo motor. The mask conveying device according to claim 1 or 2, characterized by the above.

4. Storage means for storing the value related to the torque fluctuation of the first conveying roller detected by the detecting means and the value related to the torque fluctuation of the second conveying roller described above, is provided. When the reference value measurement mask is conveyed, the values related to the torque fluctuations of the first conveying roller and the values related to the torque fluctuations of the second conveying roller detected by the detection means are stored in the storage means as the reference value of the first conveying roller and the reference value of the second conveying roller. The mask shape detection means uses the reference value of the first conveying roller and the reference value of the second conveying roller stored in the storage means. The mask conveying device according to claim 2, characterized in that.

5. The mask shape detection means is characterized in that it detects the mask shape using 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 mask conveying device according to any one of claims 1 to 4.

6. The mask shape detection means is characterized in that it detects the mask shape using at least one of the peak value of the torque value of the first conveying roller and the peak value of the torque value of the second conveying roller. The mask conveying device according to any one of claims 1 to 4.

7. The mask shape detection means is characterized in that it detects the mask shape using the time from when the fluctuation of the torque value of the first conveying roller converges until the fluctuation of the torque value of the second conveying roller converges. The mask conveying device according to any one of claims 1 to 4.

8. The mask shape detection means is characterized in that it detects the mask shape using the time from when the torque value of the first conveying roller reaches a peak until the torque of the second conveying roller reaches a peak value. The mask conveying device according to any one of claims 1 to 4.

9. When the result of comparing the value related to the torque fluctuation detected by the detection means with the reference value is within a predetermined threshold, the mask conveyed by the second conveying roller is determined to have a shape within the specified range by the mask shape detection means and is returned to the conveying path to be conveyed again by the first conveying roller. When the result of comparing the value related to the torque fluctuation detected by the detection means with the reference value is outside a predetermined threshold, the mask conveyed by the second conveying roller is determined to have a shape outside the specified range by the mask shape detection means and is conveyed outside the conveying path. The mask conveying device according to claim 1 or 2, characterized in that.

10. The mask transfer device according to any one of claims 1 to 9, a film forming means for forming a thin film on the substrate through the mask in a state where the substrate and the mask are overlapped; A film forming apparatus, comprising:

11. A first step of detecting, by a detecting means, a value related to torque variation of the first transfer roller when transferring a mask by the first transfer roller, wherein the value related to torque variation is any one of a time until the torque of the transfer roller starts to increase, a time until the torque variation converges, a peak of the torque value, and a time until the torque reaches the peak; A second step of detecting, by the detecting means, a value related to torque variation of the second transfer roller when transferring the mask transferred by the first transfer roller further downstream by the second transfer roller; A third step of detecting the shape of the mask by comparing the value related to torque variation of the first transfer roller detected in the first step with the reference value of the first transfer roller, and comparing the value related to torque variation of the second transfer roller detected in the second step with the reference value of the second transfer roller, wherein the reference value is a value related to torque variation detected by the detecting means when a flat mask without warpage is transferred; A mask shape detection method, comprising:

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