Kang, Chan-sik (Room 202, Bisiness Incubator Center Daejeon Polytechnic College, 99-1, Gayang 2-don, Dong-gu Daejeon City 300-702, KR)
Mi-da KA. (Room 202, Business Incubator Center Daejeon Polytechnic College, 99-1 Gayang 2-Don, Dong-gu Daejeon City 300-702, KR)
Kang, Chan-sik (Room 202, Bisiness Incubator Center Daejeon Polytechnic College, 99-1, Gayang 2-don, Dong-gu Daejeon City 300-702, KR)
Mi-da KA. (Room 202, Business Incubator Center Daejeon Polytechnic College, 99-1 Gayang 2-Don, Dong-gu Daejeon City 300-702, KR)
| 1. | A ballrolling holder comprising: a rolling ball (11) adapted to roll while contacting a substrate ; a number of supporting balls (12) on which the rolling ball (11) is seated and roll ; a ball supporter (13) for supporting the supporting balls (12) ; an upper case (16) which surrounds the outer peripheral surfaces of the rolling ball (11) and the supporting balls (12) and has a rolling ball guide groove (15), the diameter of which is smaller than that of the rolling ball (11); and a holder coupler (20) having a coupling means (22) which is coupled with the upper case (16) to retain the ballrolling holder (10). |
| 2. | A ballrolling holder as claimed in claim 1, wherein the rolling ball (11), which contacts the substrate, is a plastic ball. |
| 3. | A ballrolling holder as claimed in claim 1, wherein the supporting balls (12), are ceramic balls. |
| 4. | A ballrolling holder as claimed in claim 1 further comprising a spring which is positioned below the ball supporter (13) and is supported by the holder coupler (20). |
| 5. | A ballrolling holder as claimed in claim 1, wherein the upper case (16) and the holder coupler (20) are coupled in a screwcoupling type. |
| 6. | A substrate feeding device having a ballrolling holder as claimed in one of claims 15, wherein the rolling ball (11) of the ballrolling holder supports the substrate. |
| 7. | A substrate feeding device as claimed in claim 6 further comprising : a holder retainer (30) for coupling and retaining the ball rolling holders (10) and a rotation driving unit (40) for feeding the substrate which contacts the ballrolling holders (10). |
| 8. | A substrate feeding device as claimed in claim 7, wherein at least one unit is chosen from a substrate cleaning unit, a cleaning liquid suction unit, or a substrate drying unit and is fastened thereon. |
| 9. | A substrate feeding device as claimed in claim 7, wherein the rotation driving unit (40) is positioned in such a manner that it contacts the substrate along a direction which traverses the substrate. |
| 10. | A substrate feeding device as claimed in claim 8, wherein each of the ballrolling holders (10) has different height so that the substrate is slanted a predetermined angle along a direction which traverses the substrate. |
| 11. | A substrate centering device having a ballrolling holder as claimed in one of claims 15, wherein the rolling ball (11) of the ballrolling holder supports the substrate. |
Background Art A method for manufacturing a substrate, such as a glass substrate of an FPD or a semiconductor'wafer substrate, includes a process of feeding the substrate between other processes, a centering process of positioning the substrate to be fed, and a process of mechanically or chemically treating the substrate's surface. The treated substrate is subjected to a cleaning process, during which it passes through cleaning devices successively by means of a substrate feeding device.
Most of conventional substrate feeding devices, such as those disclosed in Korean Registered Patent Publication No.
375743, which discloses means for supporting and feeding a substrate while avoiding any friction with the substrate; Korean Registered Utility Model Publication No. 327347; Korean Patent Laid-Open Publication 2002-69479; Japanese Patent Laid- Open Publication No. 1998-209096; and Japanese Patent Laid-Open Publication No. 2000-286320 (the contents of which are hereby incorporated by reference), adopt a roller-feeding type as shown in FIG. 1.
However, the roller-feeding type has a problem as follows: as the glass substrate becomes larger, the shafts of the device become longer. This causes a large amount of misalignment, when roller shafts 2 are assembled, and increases the deflection of the roller shafts 2. As a result, the roller shafts 2 and rollers 1 tend to vibrate a lot and the lifespan of rotation elements, which supports the shafts at the opposite ends thereof, is shortened. This requires frequent repair and, finally, seriously decreases the productivity.
Furthermore, due to the deflection of the roller shafts 2 and the rollers 1, the large glass substrate is vulnerable to local deflection and stress concentration and thus it may be fed incorrectly. This increases the collision and friction with neighboring components and, therefore, the glass substrate may be damaged frequently. In addition, as the glass substrate
becomes larger, the shafts and driving components become larger.
This increases the manufacturing cost of the feeding device.
In addition, a cleaning device, which adopts the roller- feeding type as shown in FIG. 2, cannot clean the back surface of a substrate efficiently, due to the steric hindrance of rollers 1 and roller shafts 2, during cleaning of the substrate.
In an effort to overcome this problem, various designs have been suggested to adjust the position of a cleaning nozzle 3 and the nozzle's spraying mode. However, there exists a fundamental limitation to the cleaning efficiency, as long as the steric hindrance of the rollers and the roller shafts exists. Furthermore, a force is inevitably applied to a side frame 4, which retains the roller shafts. This poses various limitations on the type and configuration of the feeding or cleaning device. Even when one roller malfunctions, the roller shaft, to which the roller belongs, should be disassembled and every roller, which is coupled to that roller shaft, should be disassembled and re-assembled in an inefficient manner. This makes it difficult to repair and maintain the device.
In an attempt to overcome the above problems, an air- floating type feeding device has been developed as an alternative to the roller-feeding type. However, the air- floating type is expensive, has much technological difficulty,
and is difficult to repair and maintain. As a result, it is still difficult to commercialize.
Meanwhile, in an FPD manufacturing process, a substrate should undergo, after a cleaning process, a serious of processes including application of photosensitive liquid; exposure to light; development; corrosion; peeling-off; deposition; assembly; inspection; and other afterward processes for completion. In order to perform each of the processes correctly in order, a centering device is indispensable which accurately controls the position of the substrate between each of the processes, as shown in FIG. 3.
Japanese Laid-Open Patent Publication 1992-164,770 (the contents of which are hereby incorporated by reference) discloses a roller-rolling type centering device. This device, however, cannot overcome the above-mentioned problems of the roller-rolling type.
Most of conventional substrate centering devices, such as those disclosed in Japanese Patent Laid-Open Publication 2001- 230,304 (the contents of which are hereby incorporated by reference), are adapted to center a substrate through processes as follows: a robot places a substrate on a number of substrate supporting holders in the centering device ; a proximity sensor measures the initial position of the substrate ; a cylinder,
which is installed on a side of the substrate, pushes the substrate to a predetermined position ; and the robot moves the substrate to next process. However, in the step of positioning the substrate using the cylinder, a number of substrate supporting holders 5, the upper portion 6 of which has the shape of a curved surface as shown in FIGs. 4 and 5, undergo slip friction with the substrate. As a result, the cylinder should exert much force when pushing the substrate. In addition, the substrate may be positioned incorrectly. Then, the substrate may frequently collide with neighboring components and be damaged, when it is moved by the robot to next process. In order to prevent this, the substrate should be positioned correctly. However, such correct positioning takes much time. Consequently, it takes a long period of time to move the substrate between processes. Consequently, the productivity is decreased.
Even in the case of an FPD continuous process line, which adapts a conveyor system to perform several processes continuously, the centering of a substrate between processes is indispensable. However, a number of substrate supporting holders 5, the upper portion 6 of which has the shape of a curved surface, inevitably undergo slip friction with the substrate when the substrate is centered with a cylinder. As a
result, above-mentioned problems of incorrect positioning, collision with neighboring components, damage, a long period of time necessary for correct positioning of the substrate, and deterioration of productivity still exist.
Disclosure of Invention Accordingly, the present invention has been made to overcome the above-mentioned problems, and it is an object of the present invention to provide a ball-rolling holder for supporting a substrate, which minimizes the rolling friction with the substrate and makes it uniform, so that the substrate can be fed stably and centered quickly, by avoiding the roller- feeding type and the slip friction of the substrate in the centering device.
Another object of the present invention is to provide devices for feeding and cleaning a substrate, which has a ball- rolling holder for supporting a substrate fastened thereon, so that it has minimized and uniform rolling friction ; it can feed the substrate stably ; it has no steric hindrance of rollers and roller shafts and thus can perform cleaning easily; it has no limitation regarding the type and configuration of the device for feeding or cleaning; and it is easy to repair and maintain.
Still another object of the present invention is to
provide a centering device for a substrate, which has a ball- rolling holder for a substrate fastened thereon, so that it can perform a quick and correct centering process.
In order to accomplish the objects, according to an aspect of the present invention, there is provided a ball-rolling holder comprising: a rolling ball 11 adapted to roll while contacting a substrate ; a number of supporting balls 12 on which the rolling ball 11 is seated and roll; a ball supporter 13 for supporting the supporting balls 12; an upper case 16 which surrounds the outer peripheral surfaces of the rolling ball 11 and the supporting balls 12 and has a rolling ball guide groove 15, the diameter of which is smaller than that of the rolling ball 11 ; and a holder coupler 20 having a coupling means 22 which is coupled with the upper case 16 to retain the ball- rolling holder 10.
According to another aspect of the present invention, there is also provided a device for feeding and cleaning a substrate which has a ball-rolling holder according to the present invention mounted thereon. The device includes: a number of ball-rolling holders 10 according to the present invention; a holder retainer 30 for coupling and retaining the ball-rolling holders 10; and a rotation driving unit 40 for feeding the substrate 100 which contacts the ball-rolling holders 10. In
addition, at least one unit is chosen from a substrate cleaning unit, a cleaning liquid suction unit, or a substrate drying unit and is fastened thereon.
According to still another aspect of the present invention, there is provided a substrate centering device which has a ball-rolling holder according to the present invention.
The rolling ball of the ball-rolling holder supports the substrate.
Brief Description of Drawings Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which: FIG. 1 shows a conventional substrate feeding device of a roller-feeding type ; FIG. 2 is a side view showing a conventional device for feeding and cleaning a substrate of a roller-feeding type; FIG. 3 shows a conventional substrate centering device; FIG. 4 shows a conventional substrate supporting holder; FIG. 5 is an exploded perspective view showing a conventional substrate supporting holder; FIG. 6 shows the outer appearance of a ball-rolling holder for supporting a substrate according to the present
invention; FIG. 7 is an exploded perspective view showing a ball- rolling holder for supporting a substrate according to the present invention; FIG. 8 is a perspective view showing a device for feeding and cleaning a substrate according to the present invention; FIG. 9 is a side view showing a device for feeding and cleaning a substrate according to the present invention ; FIG. 10 is a top view showing a device for feeding and cleaning a substrate according to the present invention; FIG. 11 shows the comparison of steric hindrance between a roller-feeding type cleaning device and a ball-rolling type cleaning device; and FIG. 12 shows the configuration of an embodiment wherein a substrate is fed with a slant.
Best Mode for Carrying Out the Invention Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
According to the configuration of the devices of the present invention, their ball-rolling holder 10 has a rolling ball 11 and a number of supporting ball 12, on which the
rolling ball 11 is seated, as shown in FIGs. 4 and 5. As such, the rolling ball 11 can roll stably with minimum friction.
This minimizes the slip friction of a substrate during feeding.
The rolling ball 11 may be made of any material. However, in order to prevent the rolling ball 11, which is adapted to contact and support the substrate, from damaging or breaking the surface of the substrate, during feeding, the rolling ball 11 is preferably made, of a plastic ball, the hardness of which is lower than that of the substrate.
The rolling ball 11 is supported on a number of supporting balls 12 for smooth rolling. It is preferably supported by three or more supporting balls 12 for stable support.
The supporting balls 12 may be made of any material.
However, ceramic balls, which resist cleaning environment, are preferred. A ball supporter 13 is positioned below the supporting balls 12 to support them. The ball supporter 13 preferably has a supporting ball seating groove 14 so that the supporting balls 12 come in contact with one another, instead of being scattered, and support the rolling ball 11 stably.
As shown in FIG. 4, an upper case 16 has a rolling ball guiding groove 15, the diameter of which is smaller than that of the rolling ball 11, so that the rolling ball 11 is stably
seated on the supporting balls 12, instead of leaving them.
The ball supporter 13, which has the supporting balls 12 therein, and the rolling ball 11 are positioned in the upper case 16. The upper case 16 is coupled with a holder coupler 20, which has a coupling means 22 for retaining the ball-rolling holder 10. The upper case 16 and the holder coupler 20 may be coupled using any type of coupling means, including coupling screws 17,21.
Additionally, a spring 14 may be positioned below the ball supporter 13 and supported by the holder coupler 20. Due to the elastic force from the spring 14, the rolling ball 11 comes closer to the substrate.
The coupling means 22 of the holder coupler 20 is adapted to couple the ball-rolling holder 10 onto a holder retainer 30.
The coupling means 22 may have a screw to adjust the height of the ball-rolling holder 10.
Hereinafter, a device for feeding and cleaning a substrate, which has a ball-rolling holder 10 according to the present invention mounted thereon, will be explained.
The device for feeding and cleaning a substrate, which has a ball-rolling holder according to the present invention mounted thereon, comprises: a number of ball-rolling holders 10 according to the present invention ; a holder retainer 30 for
coupling and retaining the ball-rolling holders 10 ; and a rotation driving unit 40 for feeding the substrate 100 which contacts the ball-rolling holders 10. In addition, at least one unit is chosen from a substrate cleaning unit, a cleaning liquid suction unit, or a substrate drying unit and is fastened thereon.
The ball-rolling holder 10 is mounted on the device from its lower side to its upper side, so that the holder coupling means 22 of the ball-rolling holder 10 is coupled with the holder retainer 30, which is positioned below the device, and supports the back surface of a substrate, which is fed and cleaned. The holder retainer 30, which couples and retains the ball-rolling holders 10, may be configured in any type. However, the device for feeding and cleaning a substrate is generally configured in such a manner that one of its dimensions is larger than the others, along the feeding direction of the substrate.
Accordingly, the holder retainer 30 is preferably retained on a lateral surface of the device along a direction which traverses the substrate.
Furthermore, a rotation driving unit 40 is positioned in such a manner that it contacts the substrate from both lateral surfaces of the substrate and provides a driving source to move the substrate. The rotation driving unit 40 is composed of a driving motor (not shown); a driving transmission means (not
shown) for transmitting the driving force of the driving motor; and a driving roller 41 adapted to receive the driving force, contact the back surface of both lateral surfaces of the substrate, and rotate.
The substrate is supported by the ball-rolling holders 10, during feeding, and is moved only by the driving roller 41.
Accordingly, the driving roller 41 is preferably made of a material having appropriate friction force, for desired feeding of the substrate.
The configuration of the driving unit 40 and related components can be easily applied, based on that of conventional substrate feeding devices, by those skilled in the art and detailed description thereof will be omitted.
Since the substrate is supported by the ball-rolling holders 10, during feeding, a driving roller supporter 42, which supports the driving roller 41, does not need to be reinforced in a special manner.
As shown in FIGs. 6 and 7, the device for feeding and cleaning a substrate according to the present invention further comprises at least one unit fastened thereon, which is chosen from a substrate cleaning unit, a cleaning liquid suction unit, or a substrate drying unit.
The cleaning unit is composed of at least one chosen from a
spraying unit for rinsing, a brush unit, a spraying unit for cleaning, an ultrasonic unit, and the like. The cleaning unit removes alien substances from the surface and back surface of the substrate by spraying pure water and cleaning liquid on the substrate, wiping them with a brush, applying ultrasonic wave, and the like.
After the cleaning process, a shower unit and a dryer unit, such as an air knife unit, are provided. The shower unit prevents the formation of a watermark on the surface of the substrate. The dryer unit sprays high-pressure air on the surface of the substrate and removes the cleaning liquid, which remains on the surface and the back surface of the substrate, or the pure water, which has been sprayed from the shower unit.
The cleaning units are positioned along the feeding direction of the substrate with a predetermined spacing. A suction unit is positioned on the lower end of the device, which includes the substrate cleaning unit, to recover the cleaning liquid.
As shown in FIG. 8, the device for feeding and cleaning a substrate according to the present invention has little steric hindrance, which occurs on the cleaning liquid L by means of rollers and roller shafts in the roller-feeding type. Therefore, the device has excellent cleaning effect and can be easily
provided with cleaning-related units.
It is also within the scope of the present invention to differentiate the height of each of the ball-rolling holders 10, along a direction perpendicular to the feeding direction, in a section where the substrate passes through the cleaning unit, as shown in FIG. 9. In that case, the substrate is slanted a predetermined angle along a direction which traverses the substrate and the cleaning liquid flows along a direction. As a result, cleaning and drying are efficiently performed and the cleaning liquid is recovered adequately. However, if the substrate is slanted too much, it may be broken due to the stress acting on it. Accordingly, the substrate is preferably slanted 1-10°.
Hereinafter, as another aspect of the present invention, a substrate centering device, which has the ball-rolling holder for supporting the substrate according to the present invention is mounted thereon, so that it avoids the slip friction of the holder, has minimized and uniform rolling friction with the substrate, and can center the substrate quickly and accurately, will be explained.
The substrate centering device is adapted to center a substrate, which is out of position during feeding. The device is composed of a pulse motor for moving the substrate to an
adequate position, a stopper member for stopping the substrate in a predetermined position, a clamp member for maintaining the substrate in a predetermined position, a controller for controlling the operation of the pulse motor, a substrate width detection sensor for outputting numerical signals to the controller, and a substrate supporting means for supporting the substrate during centering. The centering device adapts the ball-rolling holder 10 according to the present invention as the substrate supporting means. Accordingly, the device can maintain uniform and minimal friction between the rolling ball of the ball-rolling holder 10 and the substrate and can center the substrate quickly and accurately.
The centering device, wherein the ball-rolling holder 10 according to the present invention is mounted thereon, simply replaces the substrate supporting means of conventional centering devices with the ball-rolling holder 10 according to the present invention. Accordingly, the configuration of the centering device, except the ball-rolling holder as the substrate supporting means, can be easily applied, based on that of conventional substrate feeding devices, by those skilled in the art and detailed description thereof will be omitted.
Industrial Applicability
The ball-rolling holder according to the present invention is advantageous in that: it has minimized and uniform rolling friction with a substrate, during feeding of the substrate, and can feed the substrate stably; it has no steric hindrance of rollers and roller shafts and performs cleaning easily ; it has no limitation regarding the type and configuration of the device for feeding or cleaning; and is easy to repair and maintain. Furthermore, the substrate centering device has minimized and uniform friction of the ball-rolling holder, which supports the substrate, and can perform an accurate and rapid centering process. This contributes to reduced process time and increased productivity.
In particular, even a large substrate can be fed, cleaned, or centered stably.
While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.
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