JP2024052317A - Carrier device, and in-line type vacuum processing device with the carrier device - Google Patents

Abstract

To configure a carrier device for carrying a carrier tray, where a substrate can be installed with its processed surface open, in one direction within a vacuum chamber so that reduction effect on running costs is high.SOLUTION: A carrier device TM comprises a pair of carrier units Tm1, Tm2, and the respective carrier units have carrier belts 23a, 23b wound around two rotary members 21a, 21b and 22a, 22b provided at intervals in a carrying direction of the carrier tray Tc, and revolving to travel, and a plurality of support rollers 24 supporting parts of the carrier belts where the carrier tray is mounted. The carrier belts are so configured that when the carrier belts are revolved synchronously to travel to repeatedly carry the carrier tray mounted straddling those carrier belts in an X-axial direction, the carrier belts deform preferentially to the carrier tray.SELECTED DRAWING: Figure 1

Description

The present invention relates to a transport device for transporting in one direction a transport tray on which a substrate to be processed can be placed with its processing surface open within a vacuum chamber, and an in-line vacuum processing device.

For example, the manufacturing process of flat panel displays includes a process of sequentially depositing organic and metal films on one side (film-forming surface) of a substrate to be processed such as a glass substrate (hereinafter referred to as "substrate") by vacuum deposition. In this process, an in-line vacuum film-forming apparatus is generally used. Such a vacuum film-forming apparatus as a vacuum processing apparatus has a vacuum chamber that is long in one direction, and inside the chamber, multiple film-forming sources are arranged in a row, and a transport device is provided that transports the substrate in the direction in which the film-forming sources are arranged (see, for example, Patent Document 1). In this case, the substrate is transported while placed on a transport tray with its processing surface open. Note that, due to the large area of substrates in recent years, the total weight including the substrate and transport tray can reach several hundred kilograms.

The above-mentioned transport device has a pair of transport units arranged at an interval in the Y-axis direction, with the X-axis direction and the Y-axis direction being mutually orthogonal to each other in the substrate plane. Each transport unit has a plurality of drive rollers as rotating members provided at a predetermined interval in the X-axis direction on the side walls facing each other of the vacuum chamber. Then, each drive roller of the pair of transport units is rotated and driven synchronously, and the transport tray placed across these drive rollers is transported downstream in the X-axis direction while changing over each drive roller. In such a transport device, for example, collision between the transport tray and the drive roller when changing over each drive roller, wear on the sliding surface between the transport tray and the drive roller, etc. are unavoidable. At this time, if the outer peripheral surface of the drive roller is designed to deform preferentially due to wear, etc., the vibration during transport of the transport tray becomes large, making it easy for the substrate to be displaced in the transport tray, or the transport speed of the transport tray becomes easy to vary. Such transport defects hinder the film formation with a constant thickness with precision on the film formation surface of the substrate placed on each transport tray. For this reason, the transport tray is usually designed to deform preferentially compared to the drive roller (i.e., the transport tray is considered a consumable item).

The transport trays used in in-line vacuum processing equipment consist of multiple transport trays in one set, and multiple sets are prepared for maintenance purposes. In order to maintain a high product yield, it is common for each set of transport trays to be replaced after they have been used for a preset period of time. If the transport trays are replaced periodically in this way as consumables, there is a problem in that running costs become very high.

Patent No. 6179908

In view of the above, the present invention aims to provide a conveying device that is highly effective in reducing running costs and a vacuum processing device equipped with this conveying device.

To solve the above problem, the transport device of the present invention for transporting in one direction a transport tray on which a substrate to be processed can be placed with its processing surface open in a vacuum chamber is provided with the X-axis direction and the Y-axis direction being mutually orthogonal to each other in the surface of the substrate to be processed, and the transport device includes a pair of transport units arranged at a distance in the Y-axis direction, each of which has a transport belt that runs around and is wound around two rotating members arranged at a distance in the X-axis direction, and a plurality of support rollers arranged at a distance in the X-axis direction to support the portion of the transport belt on which the transport tray is placed, and the transport belt is configured to deform preferentially compared to the transport tray when the transport belts of the pair of transport units are made to run around in a synchronous manner and the transport tray placed across the transport belts is repeatedly transported in the X-axis direction.

According to the present invention, when the transport tray is transported in the vacuum chamber, a transport belt made of, for example, steel is interposed between the rotating member or support roller and the back surface of the transport tray to function as a buffer material, and this transport belt is a consumable item that deforms preferentially, and the two transport belts are replaced as necessary. This allows for a significant reduction in running costs compared to the above-mentioned conventional example in which the transport tray itself is a consumable item that is replaced periodically. Moreover, compared to the conventional example using a drive roller, vibration during transport is suppressed as much as possible, and the variation in transport speed can also be reduced. As a result, when a single layer film or a multilayer film is formed on the film formation surface of the substrate to be processed, it becomes possible to perform the film formation process with a constant film thickness with high precision.

When a transport tray is placed between a pair of transport belts on the upstream side in the X-axis direction, and the transport belts are rotated in synchronism with each other to repeatedly transport the transport tray downstream in the X-axis direction, the deformation of the transport belt is caused not only by wear between the transport tray and the transport belt (for example, slip marks) but also by stretching. When the transport belt stretches, the transport speed varies. In the present invention, a biasing means is provided to bias at least one of the rotating members in a direction away from each other in the X-axis direction, and when the transport belt is (elastically) deformed, at least one of the rotating members is displaced in the X-axis direction by the biasing force of the biasing means, so that the tension applied to the transport belt is maintained. This makes it possible to eliminate the need to open the vacuum chamber to the atmosphere and readjust the tension of the transport belt, and to constantly maintain small variations in the transport speed.

On the other hand, if the conveyor belt is deformed (plastically) by elongation exceeding a predetermined range, the tension applied to the conveyor belt cannot be maintained. In such a case, it is possible to periodically replace the conveyor belt, but the elongation occurring in the conveyor belt differs depending on the conveying conditions, such as the weight of the conveyor tray and the conveying speed. For this reason, it is preferable to be able to prevent unnecessary belt replacement. In the present invention, a configuration can be adopted in which a detector for detecting the amount of displacement of at least one of the rotating members is further provided. According to this, for example, if the detection value of the detector is input to the control unit of the vacuum processing device or the conveying device, and if the input value exceeds a preset threshold value, a belt replacement is notified, the timing of replacement of the conveyor belt can be appropriately determined and unnecessary belt replacement can be prevented. In addition, in order to monitor the wear state of the conveyor belt, such as slip marks, an imaging element such as a CCD camera can be provided, and belt replacement can be determined from the image analysis, thereby reliably preventing conveying defects due to deformation of the conveyor belt.

To solve the above problem, the in-line vacuum processing apparatus of the present invention includes, in addition to the above-mentioned transport device, a vacuum processing unit for performing a predetermined vacuum processing on the substrate to be processed within the vacuum chamber. The apparatus further includes a control unit for controlling the operation of at least one of the transport device and the vacuum processing unit, and the control unit is communicatively connected to the detector and configured to notify information regarding belt replacement according to the detection value of the detector.

FIG. 2 is a cross-sectional view illustrating a configuration of an in-line type vacuum film forming apparatus including the transfer device of the present embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2 . FIG. 4 is an enlarged cross-sectional view of a portion surrounded by a dashed line in FIG. 3 . 5 is a cross-sectional view taken along line VV in FIG. 4 .

Below, with reference to the drawings, an embodiment of the transport device TM of the present invention and an inline type film forming device CM equipped with this transport device TM will be described using an example in which an inline type vacuum processing device is a vacuum film forming device, the substrate to be processed is a glass substrate (hereinafter referred to as "substrate Sg") having a rectangular outline, the substrate Sg is transported while placed on a transport tray Tc, and a multilayer film is formed on one side (film forming surface Sg1) of the substrate Sg by a vacuum deposition method. Below, the directions perpendicular to each other within the surface of the substrate Sg are defined as the X-axis direction and the Y-axis direction, the direction from the film forming source side described below toward the substrate Sg is defined as the Z-axis direction upward, and the substrate Sg moves from the left side to the right side in FIG. 1, and terms indicating directions will be used based on this.

Referring to FIG. 1 and FIG. 2, the vacuum film-forming apparatus CM equipped with the transport device TM of this embodiment includes first to third film-forming chambers Pc1, Pc2, and Pc3 that are connected to each other and are elongated in the X-axis direction. A vacuum pump (not shown) is connected to each of the first to third film-forming chambers Pc1, Pc2, and Pc3, and a vacuum atmosphere of a predetermined pressure can be formed in the film-forming space inside. Each of the first to third film-forming chambers Pc1, Pc2, and Pc3 is also provided with each film-forming source 1a, 1b, and 1c positioned on the same axis in the X-axis direction. Each of the film-forming sources 1a, 1b, and 1c has the same configuration and includes a crucible 11 that contains a film-forming material Vm and a heating means 12 that heats the film-forming material Vm in the crucible 11. The film-forming material Vm is appropriately selected according to the composition of each thin film to be laminated on the substrate Sg. The heating means 12 may be a resistance heating method, an induction heating method, or an electron gun method, depending on the type of film-forming material Vm. Each film-forming source 1a, 1b, and 1c also includes a rotatable shutter 13 that covers the top discharge port 11a of the crucible 11 to prevent the film-forming material Vm from reaching the substrate Sg.

Load lock chambers Lc1, Lc2 are connected to the upstream side of the first film formation chamber Pc1 in the X-axis direction and the downstream side of the third film formation chamber Pc3 in the X-axis direction via gate valves GV1, Gv2, respectively. Although not specifically shown or described, a vacuum pump and a vent valve are connected to each of the load lock chambers Lc1, Lc2, and the interior can be quickly switched between air and vacuum atmosphere. A transport tray Tc on which unprocessed substrates Sg are placed is carried into the upstream load lock chamber Lc1, and the processed substrates Sg are carried out together with the transport tray Tc from the downstream load lock chamber Lc2.

The transport tray Tc is made of a material that does not affect the film formation process even when used in a vacuum atmosphere, such as a plate made of stainless steel, invar, or aluminum, and has a rectangular opening Tc1 that faces the film formation surface Sg1 of the substrate Sg (see FIG. 2). The substrate Sg is placed on the upper surface of the transport tray Tc with its processing surface Sg facing downward. A transport device TM of this embodiment is provided in each of the film formation chambers Pc1, Pc2, and Pc3 to transport the transport tray Tc on which the substrate Sg is placed from the upstream load lock chamber Lc1 through each of the film formation chambers Pc1, Pc2, and Pc3 in sequence to the downstream load lock chamber Lc2.

3 to 5, the transport device TM includes a pair of transport units Tm1 and Tm2 arranged on both side walls of each of the deposition chambers Pc1, Pc2, and Pc3 facing each other in the Y-axis direction. Each transport unit Tm1 and Tm2 has the same configuration and includes a driving pulley 21a, 21b and a driven pulley 22a, 22b as rotating members provided at both ends of the X-axis direction of each of the first to third deposition chambers Pc1, Pc2, and Pc3, transport belts 23a, 23b wound between the driving pulleys 21a, 21b and the driven pulleys 22a, 22b, and a plurality of support rollers 24 provided at intervals in the X-axis direction to support the portions of the transport belts 23a and 23b on which the transport tray Tc is placed. Then, both outer ends of the transport tray Tc along the Y-axis direction are installed on each of the transport belts 23a and 23b so as to straddle the pair of transport belts 23a and 23b. Each support roller 24, which has a smaller diameter than the driving pulleys 21a and 21b and the driven pulleys 22a and 22b, is supported on the side walls of each film-forming chamber Pc1, Pc2, and Pc3 and can rotate freely with the rotation of the transport belts 23a and 23b. The support rollers 24 are made of, for example, stainless steel or carbon steel (S45C: hardened material), or are surface-treated, such as hard chrome plating, so as not to adversely affect the film-forming process in each film-forming chamber Pc1, Pc2, and Pc3. The distance between adjacent support rollers 24 in the X-axis direction is appropriately set according to the length of the transport tray Tc in the X-axis direction.

Drive pulleys 21a and 21b are provided at the downstream end in the X-axis direction, and drive shafts 31a and 31b of motors 3a and 3b are connected to the side walls of the deposition chambers Pc1, Pc2, and Pc3 while ensuring internal airtightness. The driven pulleys 22a and 22b are attached to the side walls of the deposition chambers Pc1, Pc2, and Pc3 via biasing means 4 that biases them in the X-axis direction away from the drive pulleys 21a and 21b (leftward in FIG. 4). In this case, a base plate 51 long in the X-axis direction is provided on the side walls of each deposition chamber Pc1, Pc2, and Pc3, and two rail members 52 are attached to the inner surface of the base plate 51 at an interval in the Z-axis direction so as to extend in the X-axis direction, and a movable plate 53 is engaged with the rail members 52 so as to be freely slidable in the X-axis direction. The driven pulleys 22a and 22b are fitted via bearings 55 to the tip of the shaft 54 erected on the rail member 52. A fixed plate 56 is also provided on the inner surface of the base plate 51, spaced apart from the movable plate 53 downstream in the X-axis direction.

The portion of the fixed plate 56 facing the movable plate 53 is recessed with a receiving hole 56a extending in the X-axis direction, and a spring seat 53a is attached to the portion of the movable plate 53 facing the fixed plate 56. A coil spring as the biasing means 4 is compressed between the spring seat 53a and the receiving hole 56a. The biasing force of the coil spring 4 is set so that the tension applied to the conveyor belts 23a and 23b is always maintained within a predetermined range. In this case, the biasing force of the coil spring 4 can be adjusted by an adjustment bolt 6 provided on the fixed plate 56. In addition, a detection piece 53b having a length extending upward in the Z-axis direction from the base plate 51 is provided on the upper surface of the movable plate 53, and a reflective laser sensor 7 as a detector is attached on the base plate 51 facing the detection piece 53b. A laser beam is irradiated from the laser sensor 7 toward the detection piece 53b, and the amount of displacement of the driven pulleys 22a and 22b in the X-axis direction can be detected from the amount of reflected light.

The conveyor belts 23a and 23b are configured to deform preferentially compared to the conveyor tray Tc when the conveyor device TM repeatedly conveys the conveyor tray Tc in the X-axis direction, and materials that do not adversely affect vacuum processing even when used in a vacuum atmosphere are appropriately selected. For example, when the total weight of the conveyor tray Tc with the substrate Sg placed thereon is in the range of 50 kg to 1200 kg, the conveyor belts 23a and 23b can be made of steel with a width in the range of 40 mm to 60 mm and a thickness in the range of 0.15 mm to 0.30 mm. Deformations that occur in the conveyor belts 23a and 23b include not only wear (e.g., slip marks) caused by surface contact with the support plate portion Tc3 of the conveyor tray Tc, but also elongation caused by an event similar to rolling when the conveyor belts 23a and 23b are sandwiched between the drive pulleys 21a and 21b, the driven pulleys 22a and 22b, or the support rollers 24 and the conveyor tray Tc. When the conveyor belts 23a and 23b are deformed to extend, the force of the coil spring 4 causes the movable plate 53 and thus the driven pulleys 22a and 22b to be displaced relative to the fixed plate 56 in the X-axis direction away from the drive pulleys 21a and 21b, maintaining the tension applied to the conveyor belts 23a and 23b, and the amount of displacement at this time is detected by the laser sensor 7. In the figure, Pp is an adhesion prevention plate that prevents adhesion to each component of the conveyor device TM.

The vacuum film-forming apparatus CM is equipped with a control unit Cu that includes a computer, memory, sequencer, etc. The control unit Cu not only controls the components that operate during film formation, such as the film-forming sources 1a, 1b, 1c and the vacuum pump, but also the operation of the transport device TM. In this case, the control unit Cu is equipped with a display that displays the operating status of each component and the transport device TM, although this is not specifically shown or described. The control unit Cu is also communicatively connected to the laser sensor 7, and the detected displacement amount is input. When the input displacement amount exceeds a threshold value that is preset in the control unit Cu, the display of the control unit Cu is configured to notify by voice or image that it is time to replace the transport belts 23a and 23b.

When a multilayer film is formed on the processing surface Sg1 of the substrate Sg by the vacuum film-forming device CM, a transport tray Tc on which the unprocessed substrate Sg is placed is transported into the upstream load lock chamber Lc1 in the atmospheric air. In this case, the insides of the film-forming chambers Pc1, Pc2, and Pc3 are evacuated by a vacuum pump and maintained at a predetermined pressure, and the film-forming material Vm in the crucible 11 is heated by the heating means 12 in each film-forming source 1a, 1b, and 1c. At this time, the discharge opening 11a on the top surface of the crucible 11 is blocked by the shutter 13. When the upstream load lock chamber Lc1 is evacuated to a predetermined pressure, the gate valve Gv1 is opened, and the transport tray Tc is transferred from the upstream load lock chamber Lc1 to the transport device TM in the first film-forming chamber Pc1, that is, the transport tray Tc is transferred so as to straddle the transport belts 23a and 23b of the pair of transport units Tm1 and Tm2. When the motors 3a and 3b rotate the drive pulleys 21a and 21b in synchronism with each other to rotate the transport belts 23a and 23b, the transport tray Tc is transported downstream in the X-axis direction, and is then transported by changing between the transport devices TM in the second and third film-forming chambers Pc2 and Pc3. During transport, the shutter 13 is appropriately retracted, so that the film-forming material Vm released from the crucible 11 according to a predetermined cosine law by vaporization or sublimation adheres to and accumulates on the film-forming surface Sg1 of the substrate Sg through the opening Tc4, forming a multilayer film on the processing surface Sg1. Then, when the transport tray Tc is transported to the most downstream side in the third film-forming chamber Pc3, the gate valve Gv2 is opened, and the transport tray Tc with the processed substrate Sg is transported to the downstream load lock chamber Lc2, where the gate valve Gv2 is closed and the transport tray Tc is opened to the atmosphere and collected.

According to the above embodiment, the transport tray Tc is placed between the pair of transport belts 23a, 23b of each transport device TM, and the transport belts 23a, 23b are synchronously rotated to repeatedly transport the transport tray Tc downstream in the X-axis direction. In this case, the steel transport belts 23a, 23b functioning as buffer materials are interposed between the drive pulleys 21a, 21b, the driven pulleys 22a, 22b, and the support roller 24 and the back surface of the support plate portion Tc3 of the transport tray Tc, and the transport belts 23a, 23b are consumables that deform preferentially. As a result, the two transport belts 23a, 23b only need to be replaced as needed, and the running costs can be significantly reduced compared to the above conventional example in which the transport tray Tc itself is a consumable item and is replaced periodically. Moreover, compared to the conventional example using a drive roller, vibration during transport is suppressed as much as possible, and the variation in transport speed can also be reduced. As a result, when forming a multilayer film on the film-forming surface Sg1, it is possible to perform the film-forming process with a precise and consistent film thickness.

In addition, when the conveyor belts 23a and 23b stretch, the driven pulleys 22a and 22b are displaced relative to each other in the X-axis direction by the biasing force of the coil spring 4, and the tension applied to the conveyor belts 23a and 23b is maintained, so that it is not necessary to open each deposition chamber Pc1, Pc2, and Pc3 to the atmosphere to readjust the tension of the conveyor belts 23a and 23b, and the conveyor speed variation can be always kept as small as possible. Moreover, a detector 7 is further provided to detect the displacement amount of the driven pulleys 22a and 22b, and the detection value of the detector 7 is input to the control unit Cu, and when the input value exceeds a preset threshold value, a belt replacement is notified, so that the replacement time of the conveyor belts 23a and 23b can be appropriately determined and unnecessary belt replacement can be prevented. Although not specifically illustrated or described, imaging elements such as CCD cameras can be installed in each deposition chamber Pc1, Pc2, and Pc3 to monitor the wear condition of the conveyor belts 23a and 23b, such as slip marks, and the need for belt replacement can be determined from image analysis, which can reliably prevent conveyor failures due to deformation of the conveyor belts 23a and 23b.

Although the embodiment of the present invention has been described above, various modifications are possible without departing from the scope of the technical concept of the present invention. In the above embodiment, the vacuum deposition method is used as an example of the vacuum processing, but the present invention is not limited to this. The present invention can also be applied to a film formation process using a sputtering method or a CVD method, or a dry etching process. In addition, the coil spring 4 is used as the biasing means, but as long as the conveyor belts 23a and 23b can relatively displace the driven pulleys 22a and 22b in the X-axis direction in response to deformation, other biasing means such as a leaf spring can be used, and the drive pulleys 21a and 21b may be configured to relatively displace in the X-axis direction instead of or in addition to the driven pulleys 22a and 22b. Furthermore, the laser sensor 7 is used as the detector 7 for detecting the displacement of the driven pulleys 22a and 22b, but the present invention is not limited to this, and other devices such as a microswitch can be used.

In the above embodiment, both outer ends of the transport tray Tc along the Y-axis direction are directly placed on each of the transport belts 23a, 23b so as to straddle the pair of transport belts 23a, 23b, respectively, but this is not limited to the above. The installation surface (contact surface) of the transport tray Tc on each of the transport belts 23a, 23b is particularly susceptible to wear, so a sheet material made of stainless steel such as SUS440C, which has high hardness (high wear resistance), may be attached only to this surface. If only this sheet material is replaced when it is damaged for some reason, the effect of reducing running costs can be further improved (i.e., the transport tray itself is not a consumable item).

CM...in-line vacuum film forming apparatus (vacuum processing apparatus), TM...transport apparatus, Cu...control unit, Tc...transport tray, Tm1, Tm2...transport units, 21a, 21b...driving pulleys (rotating members), 22a, 22b...driven pulleys (rotating members), 23a, 23b...transport belts, 24...support roller, 4...coil spring (urging means), 7...laser sensor (detector).

Claims (5)

1. A transport device for transporting a transport tray, on which a substrate to be processed can be placed with its processing surface open, in one direction within a vacuum chamber, comprising:
The X-axis direction and the Y-axis direction are mutually orthogonal directions in the plane of the substrate to be processed, and the apparatus is provided with a pair of transport units arranged at an interval in the Y-axis direction, and each transport unit has a transport belt that is wound around two rotating members arranged at an interval in the X-axis direction and runs in a circumferential direction, and a plurality of support rollers that are arranged at an interval in the X-axis direction and support a portion of the transport belt on which the transport tray is placed,
A conveying device characterized in that the conveying belts are configured to deform preferentially compared to the conveying tray when the conveying belts of the pair of conveying units are rotated in a synchronous manner to repeatedly convey the conveying tray placed across the conveying belts in the X-axis direction. The conveying device according to claim 1, further comprising a biasing means for biasing at least one of the rotating members in a direction away from each other in the X-axis direction, and when the conveying belt is deformed, the biasing force of the biasing means displaces at least one of the rotating members in the X-axis direction, thereby maintaining the tension applied to the conveying belt. The conveying device according to claim 2, further comprising a detector that detects the amount of displacement of at least one of the rotating members. An in-line vacuum processing apparatus comprising the transfer device according to claim 3 and a vacuum processing unit for performing a predetermined vacuum processing on the substrate to be processed in the vacuum chamber. The in-line vacuum processing apparatus according to claim 4, further comprising a control unit for controlling the operation of at least one of the conveying device and the vacuum processing unit, the control unit being communicatively connected to the detector and configured to notify information regarding belt replacement according to the detection value of the detector.

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