JP2024056810A - Thin film forming apparatus and thin film forming method - Google Patents

Abstract

A thin film forming apparatus and a thin film forming method are provided that are capable of performing uniform coating with high precision.
[Solution] A thin film forming apparatus 1 comprising an suction table 9 that suction-holds an object to be coated 100, a plurality of coating heads 4 that form a thin film by ejecting a coating material from an inkjet nozzle onto the surface of the object to be coated 100 that is suction-held on the suction table 9, and a gantry 3 that moves the coating heads 4 to a position above the object to be coated 100, and the gantry 3 further comprises a heat source device 31 that heats the surface of the object to be coated 100.
[Selected Figure] Figure 1

Description

The present invention relates to an inkjet type thin film forming device and a thin film forming method.

The inkjet method is a method of ejecting small amounts of ink droplets as the coating material with high precision from an inkjet coating head that uses air bubbles or piezoelectric elements as the coating head. An inkjet coating device is a device that applies the ink droplets to the target material by ejecting them with high precision. This device has been attracting attention in recent years as a device that can achieve high-precision coating of ink, and its applicability is being explored in all industrial fields, not just paper printing, and some devices are already in practical use.

The tip of the underside of the coating head is provided with multiple nozzles at a specified pitch, and the nozzle pitch determines the interval at which droplets of the coating material are ejected. The nozzle pitch is small, and the ejection or non-ejection of each nozzle can be controlled individually, making it possible to apply any shape on a flat surface without the need for a plate as in flexographic printing.

On the other hand, because the viscosity of the coating material is adjusted so that droplets can be ejected from the nozzle, the coating material spreads wet on the substrate after being ejected. This causes problems with the stability of the surface shape created by one droplet and one adjacent droplet, and the line shape at the outermost periphery of the surface shape in particular has a significant impact on the quality of the finished product.

For example, Patent Document 1 discloses a method of ejecting an alignment film material using an inkjet head and attaching it to a substrate. In the method of forming an alignment film by drying and solidifying, a solvent for adjusting surface tension and a degassing solvent are shown, which are added to the alignment film material to give it a viscosity suitable for ejection by inkjet. This is intended to improve the ejection operation of the inkjet and the leveling on the substrate after ejection, and the drying and solidification is a separate process that is transferred to a subsequent drying device (see Non-Patent Document 1).

Patent No. 3073493

Yoshihiro Iwai and Kenji Koshiishi, "Comprehensive Comparison of Liquid Crystal, PDP, and Organic EL", 1st Edition, Kogyo Chosakai Co., Ltd., July 2004, pp. 50-58

Until now, when seeking high coating position accuracy and film thickness uniformity in inkjet coating, attention has been focused primarily on the relative positional relationship between the target coating interval and the nozzle pitch of the coating head.
However, in order to utilize inkjet coating in various fields, in addition to the operation at the time of coating, it is also important to know how to manage the process from immediately after coating until the coating dries and adheres to the substrate.

In particular, when applied to the manufacture of liquid crystal glass substrates, the state of adhesion becomes extremely important as the substrate size increases. For this reason, it is desirable to apply the coating in a controlled position using the inkjet method and dry it quickly so that the controlled position can be maintained.
However, in the conventional method as shown in Non-Patent Document 1, the drying process is performed after a series of coating processes are completed. Therefore, the drying process is not performed between the start of the coating process and the start of the drying process after the substrate is set in the drying device. Therefore, there is a risk that the droplets coated on the glass substrate may move before the drying process starts, or that leveling due to overlap between droplets may occur in an unintended chain reaction.

The present invention aims to provide a thin film forming device and a thin film forming method that can apply a thin film uniformly and with high precision.

In order to solve such problems, the present invention provides a coating head unit having a suction table that suctions and holds the coating object to be coated with a thin film, a gantry that is installed on the coating head unit and can move in the longitudinal direction of the coating head unit, and a coating head unit that is installed on the gantry and can move in the width direction of the coating head perpendicular to the longitudinal direction of the coating head unit and in the vertical direction of the mounting surface of the coating head unit, and has multiple coating heads that coat the surface of the coating object with a thin film, and a head recovery device that is installed adjacent to the suction table installed on the coating head unit. The head recovery device has multiple suction ports that suck and recover each of the multiple coating heads, each of which is arranged in a row, and is composed of a light-emitting element that confirms the droplets of material discharged from the nozzle of the coating head, a camera that takes a picture of the shadow when the light-emitting element is turned on, and an electronic balance that adjusts the amount of material discharged per time between each coating head, and is characterized in that the light-emitting element and the camera that are arranged opposite each other control their respective movement mechanisms to move so as to match the coordinates of the nozzle.

The present invention provides a thin film forming device and a thin film forming method that enable highly accurate and uniform coating.

1 is a perspective view showing a configuration of a thin film forming apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating the structure of the rear side of the gantry. FIG. 2 is an enlarged view of the head recovery device. 5A to 5C are schematic diagrams illustrating the operation of the head recovery device. FIG. 4 is a functional block diagram illustrating functions of a control unit. 4 is a flowchart illustrating a thin film formation method of the thin film formation apparatus according to the embodiment. 13 is a flowchart illustrating an outer frame coating process. 10 is a flowchart illustrating an inner surface coating process. 5A and 5B are schematic diagrams illustrating an outer frame coating process of the thin film forming apparatus according to the embodiment, in which FIG. 5A shows the outward movement and FIG. 13 is a schematic diagram illustrating the structure of a gantry of a thin film forming apparatus according to a modified example. FIG. 10A and 10B are schematic diagrams illustrating an outer frame coating process of a thin film forming apparatus according to a modified example, in which FIG. 10A shows the outward movement and FIG.

Below, a mode for carrying out the present invention (hereinafter referred to as "embodiment") will be described in detail with reference to the drawings as appropriate. Note that in each drawing, common parts are given the same reference numerals and duplicated explanations will be omitted.

FIG. 1 is a perspective view showing the configuration of a thin film forming apparatus 1 according to the present embodiment.
The thin film forming apparatus 1 according to the present embodiment has a wide variety of applications, such as flat panel displays and flexibly bendable electronic paper called flexible displays that utilize electrophoretic methods. In the following description, the thin film forming apparatus 1 according to the present embodiment will be described as forming (applying) a thin film of polyimide on a glass substrate 100 used in a flat panel display. The thin film of polyimide formed (applied) on the glass substrate 100 by the thin film forming apparatus 1 according to the present embodiment will become an alignment film by being subjected to the present drying process and alignment process (rubbing), but in this description, the thin film before the present drying process and alignment process will also be referred to as an "alignment film."

The thin film forming device 1 includes a stand 2, a gantry 3, a coating head unit 5 having multiple coating heads 4, an X-axis movement mechanism 6, a Y-axis movement mechanism 7, a Z-axis movement mechanism 8, an adsorption table 9 that fixes by vacuum adsorption a glass substrate 100 on which an alignment film is to be formed (coated), a head recovery device 10, a heat source device 31, an alignment camera 32 (see FIG. 2), an alignment camera movement mechanism 33 (see FIG. 2), and a control unit 50 (see FIG. 5).

In the following explanation, as shown in FIG. 1, the longitudinal direction of the gantry 2 (the direction in which the gantry 3 moves) is defined as the X-axis, the width direction of the gantry 2 (the direction perpendicular to the X-axis on a horizontal plane) is defined as the Y-axis, and the vertical direction is defined as the Z-axis. In addition, the movement of the gantry 3 in the positive direction of the X-axis is defined as the outward path, and the movement in the negative direction of the X-axis is defined as the return path.

The gantry 3 is a gate-type gantry having an opening 3 a between it and the gantry 2 , and is provided above the gantry 2 via an X-axis movement mechanism 6 .
On the return path side of the gantry 3 , a coating head unit 5 having a plurality of coating heads 4 is provided via a Y-axis movement mechanism 7 and a Z-axis movement mechanism 8 .
A heat source device 31 is provided on the outward path side of the gantry 3. In addition, an alignment camera 32 (see FIG. 2) is provided on the outward path side of the gantry 3 via an alignment camera moving mechanism 33 (see FIG. 2).

The X-axis movement mechanism 6 is a linear motor actuator consisting of a stator (magnet plate) 6a provided on the gantry 2 and a mover (coil) 6b provided on the gantry 3, and is capable of moving the gantry 3 in the X-axis direction relative to the gantry 2.
The Y-axis moving mechanism 7 is a linear motor actuator consisting of a stator (magnet plate) 7a provided on the gantry 3 and a movable element (coil) 7b provided on the coating head unit 5, and is capable of moving the coating head unit 5 in the Y-axis direction relative to the gantry 3.
The Z-axis movement mechanism 8 is made up of a servo motor, and is capable of moving the coating head unit 5 in the Z-axis direction relative to the gantry 3 .
That is, the coating head unit 5 (coating head 4, nozzle 4a described later) can be moved in the X-axis direction by an X-axis moving mechanism 6, can be moved in the Y-axis direction by a Y-axis moving mechanism 7, and can be moved in the Z-axis direction by a Z-axis moving mechanism 8.
The X-axis moving mechanism 6 , the Y-axis moving mechanism 7 and the Z-axis moving mechanism 8 are controlled by a control unit 50 .

A coating head unit 5 is provided having a plurality of coating heads 4. In order to ensure continuity of the pitch of the nozzles that eject the alignment film material, a plurality of coating heads 4 are provided. In the example shown in Fig. 1, the coating head unit 5 is shown to have four coating heads 4 arranged in a row along the Y-axis direction, and three rows of the coating heads 4 arranged in the X-axis direction.
Furthermore, a plurality of nozzles (not shown) for ejecting the alignment film material are arranged in a row along the Y-axis direction for each coating head 4. The coating head 4 is an inkjet head that ejects small droplets of liquid from the nozzles with high precision by utilizing a piezoelectric element or the like.
The control unit 50 is capable of controlling, for each nozzle of the application head 4, whether or not to eject the alignment film material, the timing, and the amount of the alignment film material to be ejected.

Fig. 2 is a schematic diagram illustrating the structure of the rear side of the gantry 3. Note that in Fig. 2, the mover 6b of the X-axis moving mechanism 6, the Y-axis moving mechanism 7, and the Z-axis moving mechanism 8 are omitted.
2, the heat source device 31 disposed on the outward path side of the gantry 3 (the rear side in FIG. 1) is constituted by, for example, an infrared lamp and is capable of irradiating infrared rays in a substantially vertical direction. That is, it is capable of irradiating infrared rays to an object (glass substrate 100) that passes through the opening 3a (see FIG. 1) of the gantry 3 during the return path of the gantry 3.
The heat source device 31 is controlled to be turned on and off by the control unit 50 .

In addition, the thin film forming apparatus 1 of this embodiment will be described as using an infrared lamp as the heat source device 31, but this is not limited to this and may be a visible light lamp (not shown) that irradiates visible light, or an ultraviolet lamp (not shown) that irradiates ultraviolet light, as long as it is capable of heating the alignment film material applied to the glass substrate 100.
Incidentally, when an ultraviolet lamp (not shown) is used as the heat source device 31, it takes time for the intensity of the ultraviolet light irradiated to stabilize after the ultraviolet lamp is turned on. Therefore, it is preferable to provide a shutter (not shown) and control the start and stop of irradiation by opening and closing the shutter, instead of controlling the on/off of the ultraviolet lamp.
The heat source device 31 may also be a hot air blower (not shown) that heats clean air (clean air) that does not contain dust and the like and blows it onto the target (glass substrate 100). By blowing the heated clean air onto the target as a heat medium, the target (glass substrate 100) can be heated more. Alternatively, the heat source device 31 may be a combination of a hot air blower and an infrared lamp (visible light lamp, ultraviolet lamp).

The alignment camera 32 is used for positioning the glass substrate 100 adsorbed to the adsorption table 9 , and is also a camera for observing the alignment film material discharged from the application head 4 and applied to the glass substrate 100 .
The alignment camera moving mechanism 33 is capable of moving the alignment camera 32 in the Y-axis direction relative to the gantry 3. That is, the alignment camera 32 is capable of moving in the X-axis direction by the X-axis moving mechanism 6, and is capable of moving in the Y-axis direction by the alignment camera moving mechanism 33.
The X-axis moving mechanism 6 and the alignment camera moving mechanism 33 are controlled by a control unit 50. An image captured by the alignment camera 32 is transmitted to the control unit 50 and used to correct the position of the coating head 4.

1, the suction table 9 is capable of vacuum-suctioning and fixing the glass substrate 100. The suction table 9 is also provided with a θ rotation mechanism (not shown) made up of a servo motor, and is capable of rotating the table by a rotation angle θ around the Z-axis.
The attachment/detachment of the glass substrate 100 and the rotation angle θ of the suction table 9 are controlled by a control unit 50 .

Next, the head recovery device 10 will be further described with reference to Figures 3 and 4. Figure 3 is an enlarged view of the head recovery device 10.
The head recovery device 10 is a device that ejects liquid from the nozzles of the application head 4 to prevent the nozzles from clogging, and detects when the nozzles have been cleared of clogging.
The head recovery device 10 includes a suction port 11, an LED (Light Emitting Diode) 12, a camera 13, an LED movement mechanism 12A that moves the LED 12 in the Y-axis direction, a camera movement mechanism 13A that moves the camera 13 in the Y-axis direction, and an electronic balance 14. The electronic balance 14 ejects the alignment film material from the nozzles of the coating heads 4, and adjusts the amount of ejection per time between each coating head 4.

The suction ports 11 are connected to a vacuum chamber (not shown) or the like, and are arranged so that their positions correspond to the positions of the multiple coating heads 4 provided in the coating head unit 5 when viewed in the Z-axis direction. That is, corresponding to the coating head unit 5 shown in FIG. 1, four suction ports 11 are arranged in a row along the Y-axis direction, and the rows of the suction ports 11 are arranged in three rows in the X-axis direction.

The LEDs 12 are arranged so as to correspond to the positions of the coating heads 4 arranged in a row along the Y-axis direction provided in the coating head unit 5. That is, four LEDs 12 are arranged in a row along the Y-axis direction corresponding to the coating head unit 5 shown in Fig. 1. The LEDs 12 can be moved in the Y-axis direction by an LED moving mechanism 12A.
The LED 12 is controlled to be turned on and off by the control unit 50 .

The cameras 13 are arranged so as to correspond to the positions of the coating heads 4 arranged in a row along the Y-axis direction provided in the coating head unit 5. That is, four cameras 13 are arranged in a row along the Y-axis direction corresponding to the coating head unit 5 shown in Fig. 1. The cameras 13 can be moved in the Y-axis direction by a camera movement mechanism 13A.
The image captured by the camera 13 is transmitted to the control unit 50 .

Figure 4 is a schematic diagram explaining the operation of the head recovery device 10. Note that Figure 4 is a schematic diagram viewed on the X-Z plane of Figure 1. Also, in Figure 1, multiple coating heads 4 and suction ports 11 are arranged in the X-axis direction, but Figure 4 omits the illustration of all coating heads 4 and suction ports 11 other than those corresponding to the nozzles to be inspected.

First, the control unit 50 (head recovery control unit 51 described later) controls the X-axis movement mechanism 6 and the Y-axis movement mechanism 7 to move the coating head 4 so that it corresponds to the suction port 11. The control unit 50 (head recovery control unit 51) also controls the LED movement mechanism 12A and the camera movement mechanism 13A to move the LED 12 and the camera 13 so that their Y-axis coordinates match the Y-axis coordinate of the nozzle 4a to be inspected. The camera 13 also has an X-axis movement mechanism (not shown) that moves the focal position of the image to match the X-axis coordinate of the nozzle 4a to be inspected.

Next, the control unit 50 (head recovery control unit 51) controls the application head 4 to perform a recovery operation in which the nozzles 4a eject droplets 4b of the alignment film material. The ejected droplets 4b of the alignment film material enter the suction port 11.
At this time, the control unit 50 (head recovery control unit 51) turns on the LED 12 and captures an image with the camera 13. The ejected droplets 4b of the alignment film material are captured as shadows in the image captured by the camera 13. This makes it possible to detect recovery from clogging of the nozzles 4a.

The nozzle 4a is cleared by ejecting droplets 4b of the alignment film material. However, if the clogging cannot be cleared by ejection control alone, the control unit 50 (head recovery control unit 51) may control the Z-axis movement mechanism 8 (see FIG. 1) to lower the application head 4 so that it comes into contact with the suction port 11, and perform suction recovery. The control unit 50 (head recovery control unit 51) then controls the Z-axis movement mechanism 8 (see FIG. 1) to return it to a predetermined height, eject droplets 4b of the alignment film material from the nozzle 4a, and take an image with the camera 13 to confirm recovery.

FIG. 5 is a functional block diagram illustrating the functions of the control unit 50.
The control unit 50 is capable of controlling the movement positions of the X-axis moving mechanism 6 , the Y-axis moving mechanism 7 , the Z-axis moving mechanism 8 , the LED moving mechanism 12 A, the camera moving mechanism 13 A and the alignment camera moving mechanism 33 .
The control unit 50 is also capable of controlling the attachment/detachment and rotation angle θ of the glass substrate 100 on the suction table 9 .
The control unit 50 is also capable of controlling the turning on and off of the LEDs 12 and the heat source device 31 .
The control unit 50 is also capable of controlling the presence or absence and timing of ejection of the alignment film material for each of the nozzles of the multiple application heads 4 .
Furthermore, the control unit 50 is configured to receive images captured by the camera 13 and the alignment camera 32 .

The control unit 50 includes a head recovery control unit 51 , an outer frame coating process control unit 52 , and an inner surface coating process control unit 53 .
The head recovery control unit 51 performs control to recover the nozzles of the application head 4 .
The outer frame coating process control unit 52 performs control for forming the outer frame of the alignment film to be coated on the glass substrate 100 .
The inner surface coating process control unit 53 controls the coating of the alignment film material onto the inside of the outer frame of the alignment film formed by the outer frame coating process control unit 52 .

Next, the thin film formation method of the thin film formation apparatus 1 according to this embodiment will be described with reference to Figures 6 to 8.

In step S1, the head recovery control unit 51 of the control unit 50 checks whether the alignment film material can be normally dropped from the nozzle of the application head 4. In addition, the head recovery control unit 51 uses the electronic balance 14 to adjust the amount of the alignment film material discharged from the nozzle of the application head 4.
Specifically, the head recovery control unit 51 controls the X-axis moving mechanism 6 and the Y-axis moving mechanism 7 to move the coating head 4 so as to correspond to the suction port 11. In addition, the head recovery control unit 51 controls the LED moving mechanism 12A and the camera moving mechanism 13A to move the LED 12 and the camera 13 so that their Y-axis coordinates coincide with the Y-axis coordinate of the nozzle to be inspected.
Then, the head recovery control unit 51 controls the application head 4 to eject the alignment film material from the nozzles, and the ejected droplets of the alignment film material are photographed by the camera 13 for confirmation.
If the nozzle becomes clogged and the ink cannot be dropped, the above-mentioned suction recovery is performed.
Once it has been confirmed that the liquid can be dropped normally from the nozzles of the application head 4, the process proceeds to step S2.

In step S2, the control unit 50 controls the suction table 9 to adsorb the glass substrate 100 placed on the suction table 9 by an external substrate loading mechanism (not shown) (substrate loading). The control unit 50 also controls the X-axis movement mechanism 6 and the alignment camera movement mechanism 33 to move the alignment camera 32, and confirms the position of the glass substrate 100 adsorbed to the suction table 9 based on the image captured by the alignment camera 32. The control unit 50 controls the movement of the coating head 4, which will be described later, based on the position information of the glass substrate 100 confirmed here.

In step S3, the outer frame application process control unit 52 of the control unit 50 applies and forms an outer frame of the alignment film on the glass substrate 100. Here, the outer frame application process shown in step S3 will be further described with reference to FIG.
First, in step S31, the outer frame coating process control unit 52 controls the Y-axis moving mechanism 7 to move the Y-axis position so that the coating head 4 passes through the area where the outer frame pattern 110 (see Figure 9 (a)) is formed in step S32 described later (coating head Y-axis positioning).

In step S32, as shown in FIG. 9(a), the outer frame coating process control unit 52 controls the X-axis moving mechanism 6 to move the gantry 3 in the forward direction, and also controls the coating head 4 to control the timing at which droplets of the alignment film material are dropped from the nozzles of the coating head 4.
As a result, an outer frame pattern 110 of the alignment film is applied to the glass substrate 100 .

When the movement of the gantry 3 in the forward direction is completed, the process proceeds to step S33.
In step S33, the outer frame coating process control section 52 turns on the infrared lamp serving as the heat source device 31 (heat source device ON).

9B, in step S34, the outer frame coating process control unit 52 controls the X-axis movement mechanism 6 to move the gantry 3 in the return direction. In this way, the glass substrate 100 that has passed through the opening 3a of the gantry 3 (see FIG. 1) is irradiated with infrared rays (heating region) 34.
This causes the outer frame pattern 110 of the alignment film applied to the glass substrate 100 in step S32 to dry.

When the backward movement of the gantry 3 is completed, the process proceeds to step S35.
In step S35, the outer frame coating process control section 52 turns off the infrared lamp serving as the heat source device 31 (heat source device OFF).

In step S36, the outer frame coating process control unit 52 determines whether or not the predetermined number of times has been completed.
In the outer frame coating process shown in step S3, coating and drying of the outer frame pattern 110 are repeated multiple times to make the outer frame pattern 110 have a predetermined height, and if the predetermined number of times has not been completed (S36, No), the process of the outer frame coating process control unit 52 returns to step S31. If the predetermined number of times has been completed (S36, Yes), the outer frame coating process (step S3) shown in Fig. 7 is completed, and the process proceeds to step S4 in Fig. 6.

6, in step S4, the inner surface coating process control unit 53 of the control unit 50 applies an alignment film material to the inner surface surrounded by the outer frame pattern 110 (see FIG. 9) formed in step S3. Here, the inner surface coating process shown in step S4 will be further described with reference to FIG.
In step S41, the inner surface coating process control unit 53 controls the Y-axis movement mechanism 7 to move the position of the Y-axis so that the coating head 4 is positioned at its initial position in the Y-axis direction (Y-axis positioning of the coating head).

In step S42, the inner surface coating process control unit 53 controls the X-axis movement mechanism 6 to move the gantry 3, and also controls the coating head 4 to control the timing at which droplets of the alignment film material are dropped from the nozzles (gantry movement/coating). Note that the movement of the gantry 3 in S42 can be either the outward or return path.
As a result, the alignment film material is applied to the inner surface surrounded by the outer frame pattern 110 (see FIG. 9) formed in step S3.

In step S43, the inner surface coating process control unit 53 determines whether or not a predetermined number of coating operations (N times) have been completed.
As described later, the inner surface surrounded by the outer frame pattern 110 is coated N times while moving the coating head 4 by 1/N of the nozzle pitch. As a result, the pitch of droplets dropped on the inner surface surrounded by the outer frame pattern 110 becomes 1/N of the nozzle pitch of the coating head 4. This makes it possible to make the film thickness uniform.
If the predetermined number of coating operations has not been completed (S43: No), the process proceeds to step S44, where the inner surface coating process control unit 52 controls the Y-axis movement mechanism 7 to move the coating head 4 by 1/N nozzle pitch, and then the process returns to step S42.
When the predetermined number of coating operations has been completed (S43: Yes), the inner surface coating process (step S4) shown in FIG. 8 is completed, and the process proceeds to step S5 in FIG.

In step S5, the control unit 50 controls the suction table 9 to release the suction of the glass substrate 100 placed on the suction table 9. The glass substrate 100 on which the alignment film has been applied is removed from the thin film forming apparatus 1 by an external substrate loading mechanism (not shown) (substrate unloading).
The glass substrate 100 removed from the thin film forming apparatus 1 is sent to a drying treatment apparatus (not shown) for carrying out the main drying treatment.

In this way, the thin film forming apparatus 1 according to this embodiment forms an alignment film using an inkjet method, so there is no need for a plate as in conventional flexographic printing methods, and it can handle the formation of a small number of different types of alignment films (in other words, the manufacture of a small number of different types of flat panel displays).

Furthermore, when forming an alignment film on the glass substrate 100, the thin film forming apparatus 1 according to this embodiment forms the outer frame pattern 110 of the alignment film, and then applies an alignment film material within the frame.
9, when forming the outer frame pattern 110 of the alignment film, the alignment film material applied on the glass substrate 100 is heated by a heat source device 31 such as an infrared lamp, so that it is possible to reduce the spread of the applied alignment film material from the applied position on the glass substrate 100. This reduces the spillover from the alignment film formation region, and allows the alignment film material to be used efficiently.
In addition, the linearity of the edges of the alignment film can be improved, which allows the non-display area of the flat panel display to be further reduced. Furthermore, in a glass substrate for multiple cutouts, the distance between adjacent alignment film patterns can be reduced, which increases the number of flat panel displays that can be cut out from a single glass substrate.

Next, the alignment film material applied inside the frame is blocked by the outer frame so that it does not spread any further. This reduces the spillover (wetting and spreading) from the alignment film formation area, allowing the alignment film material to be used efficiently.

Furthermore, the thin film forming apparatus 1 according to this embodiment is provided with a head recovery device 10 adjacent to the suction table 9. This makes it possible to prevent clogging of the coating head 4 and recover (clean) the nozzle, and also to suitably control the amount of droplets of the alignment film material dropped from the nozzle of the coating head 4 and the timing of dropping.
In addition, by capturing an image of the alignment film material being discharged from the application head 4 with the camera 13, it is possible to check whether the material is being discharged correctly without clogging.
In addition, the irradiation area of the heat source device 31 (heating area 34 shown in Figure 9 (b)) is directed toward the glass substrate 100 below the gantry 3, so as to not promote clogging of the coating head 4.

<Modification>
The thin film forming apparatus according to this embodiment is not limited to the configuration of the above embodiment, and various modifications are possible without departing from the spirit of the invention.
10 is a schematic diagram for explaining the structure of the gantry 3 of the thin film forming apparatus according to the modified example. Compared with the gantry 3 according to the present embodiment (see FIG. 2), the gantry 3 according to the modified example (see FIG. 10) is also provided with a heat source device 35 on the return path side (front side in FIG. 1) of the gantry 3. The heat source device 35 is, for example, an infrared lamp, like the heat source device 31, and is capable of irradiating infrared rays in a substantially vertical direction. That is, the heat source device 35 is capable of irradiating infrared rays to an object that passes through the opening 3a (see FIG. 1) of the gantry 3 during the forward path of the gantry 3.
The heat source device 35 is controlled to be turned on and off by the control unit 50 .

FIG. 11 is a schematic diagram for explaining an outer frame coating process of a thin film forming apparatus according to a modified example, where (a) shows the outward movement and (b) shows the return movement.
As shown in FIG. 11(a), when the gantry 3 is moved in the forward direction, the coating head 4 is controlled to control the timing at which droplets of the alignment film material are dropped from the nozzles of the coating head 4, and the heat source device 35 is turned on to irradiate the glass substrate 100 with infrared rays (heating area) 36.
Also, as shown in FIG. 11(b), when the gantry 3 is moved in the return direction, the coating head 4 is controlled to control the timing at which droplets of the alignment film material are dropped from the nozzles of the coating head 4, and the heat source device 31 is turned on to irradiate the glass substrate 100 with infrared rays (heating area) 34.
In this manner, according to the thin film forming apparatus of the modified example, the alignment film material can be dropped and dried both on the forward and return passes, and the tact time for forming the outer frame can be shortened.
In addition, the time from application (droplet application of the alignment film material) to drying (irradiation with infrared rays) can be shortened, so that the linearity of the outer frame is further improved.

The apparatus may further include a heating means (not shown) for heating the glass substrate 100 adsorbed to the adsorption table 9 (see FIG. 1), and by heating the glass substrate 100 in the outer frame forming process (step S3), the drying of the droplets of the alignment film material that have been dropped may be promoted.

1 Thin film forming device 2 Frame 3 Gantry 3a Opening 4 Coating head 4a Nozzle 4b Droplet of alignment film material 5 Coating head unit 6 X-axis moving mechanism 6a Stator 6b Movable element 7 Y-axis moving mechanism 7a Stator 7b Movable element 8 Z-axis moving mechanism 9 Suction table 10 Head recovery device 11 Suction port (discharge position)
12 LED (imaging device)
12A LED moving mechanism (imaging device)
13 Camera (imaging device)
13A Camera movement mechanism (imaging device)
31 Heat source device 32 Alignment camera 33 Alignment camera moving mechanism 34 Infrared rays (heating area)
35 Heat source device 36 Infrared (heating area)
50 Control unit 51 Head recovery control unit 52 Outer frame coating process control unit 53 Inner surface coating process control unit 100 Glass substrate (coating object)
110 Outer frame pattern

In order to solve such problems, the present invention is characterized by comprising an adsorption table that adsorbs and holds an object to be coated, a plurality of coating heads that form a thin film by dripping a coating material from an inkjet nozzle onto the surface of the object to be coated that is adsorbed and held on the adsorption table, a gantry that moves the coating heads to a position above the object to be coated, a first heat source device that is disposed on the gantry and that heats the surface of the object to be coated, a second heat source device that is disposed on the opposite side in the direction of movement of the gantry and that heats the surface of the object to be coated, and a control device that controls the adsorption table, the coating heads, the gantry, the first heat source device, and the second heat source device .

1 Thin film forming device 2 Frame 3 Gantry 3a Opening 4 Coating head 4a Nozzle 4b Droplet of alignment film material 5 Coating head unit 6 X-axis moving mechanism 6a Stator 6b Movable element 7 Y-axis moving mechanism 7a Stator 7b Movable element 8 Z-axis moving mechanism 9 Suction table 10 Head recovery device 11 Suction port (discharge position)
12 LED (imaging device)
12A LED moving mechanism (imaging device)
13 Camera (imaging device)
13A Camera movement mechanism (imaging device)
31 Heat source device (first heat source device)
32 Alignment camera 33 Alignment camera moving mechanism 34 Infrared (heating area)
35 Heat source device (second heat source device)
36 Infrared (heating area)
50 Control unit 51 Head recovery control unit 52 Outer frame coating process control unit 53 Inner surface coating process control unit 100 Glass substrate (coating object)
110 Outer frame pattern

Claims (4)

a stand having a suction table for suction-holding an object to be coated with a thin film;
a gantry provided on the gantry and movable in a longitudinal direction of the gantry;
a coating head unit provided on the gantry, movable in a width direction of the frame perpendicular to a longitudinal direction of the frame and in a vertical direction of a mounting surface of the frame, the coating head unit having a plurality of coating heads for coating a thin film on a surface of the coating object;
a head recovery device provided adjacent to a suction table provided on the stand,
The head recovery device includes a plurality of suction ports for suction recovery of each of the plurality of coating heads, the suction ports being arranged in a line,
The device comprises a light-emitting element for confirming droplets of material discharged from the nozzles of the coating head, a camera for taking pictures of the shadows of the light-emitting element when it is turned on, and an electronic balance for adjusting the amount of material discharged per one time between each coating head;
The ink-jet type thin film forming apparatus is characterized in that the light-emitting element and the camera, which are arranged opposite to each other, are moved to coincide with the coordinates of the nozzle by controlling their respective moving mechanisms. a stand having a suction table for suction-holding an object to be coated with a thin film;
a gantry provided on the gantry and movable in a longitudinal direction of the gantry;
a coating head unit provided on the gantry, movable in a width direction of the frame perpendicular to a longitudinal direction of the frame and in a vertical direction of a mounting surface of the frame, the coating head unit having a plurality of coating heads for coating a thin film on a surface of the coating object;
a head recovery device provided adjacent to a suction table provided on the stand,
The head recovery device includes a light-emitting element for checking droplets of material discharged from the nozzles of the coating head, a camera for taking pictures of the shadows of the light-emitting element when it is turned on, and an electronic balance for adjusting the amount of material discharged per one time between each coating head.
The light emitting elements correspond to each of the plurality of coating heads and are arranged in a line,
The ink-jet type thin film forming apparatus is characterized in that the light-emitting element and the camera, which are arranged opposite to each other, are moved to coincide with the coordinates of the nozzle by controlling their respective moving mechanisms. An inkjet type thin film forming device according to claim 1 or 2, characterized in that the object to which the thin film is applied is a substrate. An inkjet type thin film forming device according to claim 1 or 2, characterized in that the object to which the thin film is applied is a glass substrate.

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