Substrate transporting apparatus and substrate guide unit for use therein

An apparatus for transporting substrates and a guide unit are disclosed herein. A guide unit can prevent a substrate from shaking in a side direction when the substrate is transported by the rotation of a transporting roller. The guide unit includes an inner ring and an outer ring. The outer ring includes a ring-shaped guide protruding from an outer circumferential surface of the outer ring in a side direction. The outer circumferential surface of the outer ring comes in contact with the bottom edge of a substrate to support the substrate, and a side surface of the guide comes in contact with the side of the substrate to prevent the substrate from traveling in a side direction. The inner ring rotates with the shaft, and the outer ring rotates by a friction force with the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. non-provisional patent application claims priority under 35 U.S.C §119 of Korean Patent Application 2007-46602 filed on May 14, 2007, the entirety of which is hereby incorporated by reference.

BACKGROUND

The present invention relates to apparatuses for use in substrate manufacturing and, more specifically, to a substrate transporting apparatus and a guide unit for use therein.

Lately, data processing apparatuses are rapidly being advanced with multiple functions and higher data processing speed. Each of these data processing apparatuses includes a display provided to display operated information. While cathode ray tubes (CRTs) are conventionally used as displays, the use of flat panel displays are significantly increasing with the recent rapid advance in semiconductor technologies. Flat panel displays are advantageous in lightness and small occupied area. Although there are many kinds of flat panel displays, liquid crystal displays (LCDs) have widely been used because they are advantageous in low power dissipation, small volume, and low driving voltage.

A variety of processes are performed to manufacture these flat panel displays. A substrate for use in a flat panel display is transported through a transporting apparatus to a chamber in which the respective processes are performed. Inside the process chamber, the substrate is. transported during a process.FIG. 1illustrates a typical transporting apparatus900, andFIG. 2is an enlarged perspective view of a substrate and side rollers shown inFIG. 1. Referring toFIGS. 1 and 2, the transporting apparatus900includes rotatable shafts920disposed to be parallel with each other and transporting rollers940provided at the shaft920to rotate with the shaft920. A side roller960is installed between the shafts920supporting a side surface of a substrate S to guide the linear transportation of the substrate S. The rotation force of the shafts920and the transporting rollers940allows the substrates S to move linearly, and the linear movement of the substrate S allows the side rollers960to rotate.

However, unless the position of the side roller960is provided precisely, the side of the substrate S is liable to collide against the side roller960to damage the substrate S. Moreover, if the traveling substrate S is shaken up and down, a friction is liable to be generated between the substrate S and the side roller960in a length direction of the side roller960to damage the substrate S.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention are directed to a substrate transporting apparatus. In an exemplary embodiment, the substrate transporting apparatus may include: a plurality of rotatable shafts arranged in a row; transporting rollers fixedly coupled with the shaft to rotate with the shaft; and a guide unit configured to guide the linear movement of a substrate transported by the transporting rollers, the guide unit including an outer circumferential surface contacting the bottom edge of the substrate and an outer ring having a guide protruding outwardly from the outer circumferential surface to contact the side of the substrate.

In another exemplary embodiment, the substrate transporting apparatus may include: a plurality of rotatable shafts arranged in a row; a plurality of transporting rollers fixedly coupled with the shaft to rotate with the shaft; and a guide unit configured to guide the linear movement of a substrate transported by the transporting rollers and coupled with the shaft.

Exemplary embodiments of the present invention are directed to a guide unit provided at a substrate transporting apparatus to guide the linear movement of a substrate. In an exemplary embodiment, the guide unit may include: an outer ring having the center where a through-hole is formed and including a guide extending outwardly from an outer circumferential surface thereof; an inner ring inserted into the through-hole of the outer ring, the inner ring having the center where a through-hole is formed; and a plurality of bearings provided between the outer ring and the inner ring.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

While the embodiments of the present invention will specify a rectangular glass substrate used to manufacture a liquid crystal display panel, the present invention is not limited thereto and may be applied to any apparatus for transporting a rectangular workpiece.

FIG. 3illustrates a substrate treating facility1with a substrate transporting apparatus20according to the present invention. Referring toFIG. 3, the substrate treating facility1includes a plurality of chambers10, the substrate transporting apparatus20, and a chemical injection member30. Each of the chambers10defines a space where a process of a substrate S is performed. The substrate transporting apparatus20linearly moves the substrate S between the chambers10and inside each of the chamber10. The chemical injection member30is installed inside the chamber10and supplies chemicals, such as a cleaning solution or an etching solution, according to the kind of processes performed for the substrate S. These components will now be described below in detail.

Each of the chambers10may have the shape of substantially hollow rectangular parallelepiped. An inlet12is formed at one side of the respective chamber10, and an outlet14is formed at the other side thereof. A substrate S is put into the chamber10through the inlet12and taken out of the chamber10through the outlet14. A substrate S travels from a foremost chamber among the chambers10to a hindmost chamber among the chambers10. The substrate S is subjected to predetermined processes in the respective chambers10. For example, a cleaning process may be performed in one chamber10aamong the chambers10; a cleaning process may be performed in a chamber10bdisposed in front of the chamber10ain which the cleaning process is performed; and a drying process may be performed in a chamber10cdisposed in the back of the chamber10ain which the cleaning process is performed. In the case of the chamber10ain which the cleaning process is performed, the chemical injection member30may include a top injection member32configured to inject a cleaning solution to a top surface of the substrate S and a bottom injection member34configured to inject the cleaning solution to a bottom surface thereof.

The substrate transporting apparatus20is disposed inside the respective chambers10.FIG. 4is a perspective view of the substrate transporting apparatus20shown inFIG. 3. Referring toFIGS. 3 and 4, the substrate transporting apparatus20includes a plurality of transporting rollers120, a plurality of shafts140, and a guide unit200. The shafts140are linearly arranged inside each chamber10and provided from a position adjacent to an inlet12to a position adjacent to an outlet14. The plurality of transporting rollers120are fixedly coupled with the respective shafts140in the length direction of the shafts140. The shafts140rotate on their central axes by means of a driving member (not shown), and the transporting roller120rotates with the shaft140.

The driving member may be an assembly including pulleys, belts, and a motor. The assembly including pulleys, belts, and a motor will be well known in the art and will not be described in further detail. The shafts140and the transporting rollers120rotate by means of the driving member, and the substrate S travels linearly along the shafts140while the bottom surface of the substrate S is in contact with the transporting roller120. Each of the shafts140is horizontally disposed to horizontally transport the substrate S.

The guide unit200is disposed at both ends of the shaft140to guide the linear traveling of the substrate S. The guide unit200supports sides S1of the substrate S in a side direction to prevent the substrate S from shaking left and right in the traveling direction of the substrate S. Among four sides of the substrate S, the above sides S1are parallel with the traveling direction of the substrate S.

FIG. 5is an exploded cross-sectional view of the guide unit200, andFIG. 6is an assembled cross-sectional view thereof.FIG. 7is a perspective view of the assembled guide unit200fixedly coupled with shafts.

Referring toFIGS. 5 through 7, the guide unit200includes an outer ring220, an inner ring240, a retainer250, bearings260, and a fixing member270.

The outer ring220may have the shape of substantially a cylinder with a first through-hole222formed at the center thereof. The outer ring220is disposed to let its central axis be collinear with a central axis of the shaft140. Since the outer ring220has the same diameter as a transporting roller120, a substrate S comes in contact with an outer circumferential surface of the transporting roller120and an outer circumferential surface of the outer ring220.

The guide230extends toward the outside of the outer ring220from the central region of the outer circumferential surface224of the outer ring220in a radius direction of the outer ring220. The guide230may have the shape of substantially a circular ring. The thickness of the guide230becomes smaller as being far away from the center of the outer ring220. The guide230is connected to the side of the substrate S to prevent the substrate S to travel in a side direction.

The guide230has an inclined surface232, which is inclined at an obtuse angle to the outer circumferential surface224of the outer ring220. The guide230is symmetrical relative to an axis702that is perpendicular to a central axis701of the outer ring220. When a substrate S shakes in up and down direction or left and right direction, the inclined surface232guides the shaking substrate S to be loaded on the outer circumferential surface224of the outer ring220. Alternatively, the guide230may have a surface that is perpendicular to the outer circumferential surface224of the outer ring220.

The outer circumferential surface224of the outer ring220is divided into two regions, i.e., a first circumferential surface224aand a second circumferential surface224b, on the basis of the guide230. The inclined surface232of the guide230includes a first inclined surface232aand a second inclined surface232b. The first inclined surface232ais positioned adjacent to the first outer circumferential surface224a, and the second inclined surface232bis positioned adjacent to the second outer circumferential surface224b. First, the guide unit200is provided to make the first outer circumferential surface224alook toward the substrate S. Thus, the first outer circumferential surface224acomes in contact with the bottom surface of the substrate S, and the first inclined surface232acomes in contact with the side S1of the substrate S. If the first outer circumferential surface224aand the first inclined surface232aare deteriorated by abrasion or the like, the install direction of the guide unit200may be varied to make the second circumferential surface224alook toward a substrate S. In this case, the second outer circumferential224bcomes in contact with a bottom surface of the substrate S to support the substrate S, and the second inclined surface232bcomes in contact with the side S1of the substrate S.FIG. 12illustrates the guide unit200installed to be opposite to that shown inFIG. 6.

As illustrated, the guide230protrudes toward the center of the outer circumferential surface224of the outer ring220from the outside of the outer ring220. However, in this embodiment, a central region includes not only the center of the outer circumferential surface224of the outer ring220but also a region except both ends of the outer circumferential surface224of the outer ring220to provide the first circumferential surface224aand the second outer circumferential surface224b.

The inner ring240is inserted into the first through-hole222of the outer ring220. The inner ring240may have the shape of substantially a cylinder with a second through-hole242formed at the center thereof. In the second through-hole242, the shaft140is inserted. The inner ring240is fixedly coupled with the shaft140to rotate with the shaft140due to a rotation force of the shaft140. For example, the shaft140may be forcibly inserted into the inner ring240.

The inner ring240includes a main body240aand a sub-body240b. A portion of the second through-hole242aformed at the center of the main body240ais provided to have a similar diameter to that of the shaft140and have a regular diameter in a length direction of the shaft140. A portion of the second through-hole242bformed at the sub-body240bextends from the a portion of the second through-hole242aformed at the center of the main body240aand is provided to increase its diameter as being far away from the inner ring240. That is, the second through-hole242aprovided at the main body240ahas a substantially cylindrical shape and the second through-hole242bprovided at the sub-body240bhas a substantially conic shape. Screw threads246are formed at the outer circumferential surface of the sub-body240b.

A plurality of bearings260and a retainer250are inserted between the outer ring220and the inner ring240. The retainer250may have the shape of substantially a circular ring. Circular through-holes252are formed along the side of the retainer ring250. The bearings260are inserted into the through-holes252to be rotatably disposed within the through-hole252. The bearings260protrude partially inwardly and outwardly from the retainer250. Grooves228and248are formed at the outer circumferential surface244of the inner ring240and the inner circumferential surface226of the outer ring220to correspond to each other, respectively. Partial regions of the bearing260protruding from the retainer250are inserted into the grooves228and248. The bearings260are annularly arranged along the circumference of the retainer250to be spaced apart from each other at regular intervals. A plurality of annular arrangements are provided. In this embodiment, two columns of bearings260are illustrated. Thus, loads applied to the bearings260are distributed to extend the lifetime of the bearings260.

Due to the bearings260, the outer ring220and the inner ring240rotate independently without interference from their rotations. That is, the inner ring240rotates by a rotation force of the shaft140and the outer ring220rotates by a friction force with the substrate S.

The shaft140is inserted to penetrate the second through-hole242of the inner ring240. The fixing member270may include a wedge280and a pressuring member.

FIG. 8is a perspective view of the wedge280shown inFIG. 5. Referring toFIGS. 5 and 8, a third through-hole282is formed at the center of the wedge280, and a shaft140(seeFIG. 4) penetrates the third through-hole282. The wedge280may have a substantially conic shape. The wedge280has a similar length to the sub-body240bof the inner ring240and is inserted into the second through-hole242bof the sub-body240b. The third through-hole282is provided with the same size in the length direction of the wedge280. The wedge280may be made of an elastic material. Since the wedge includes a cutting portion lengthwise, it has a first stage284aand a second stage284bwhich are opposite to each other and spaced apart from each other. Among both faces of the wedge280, a small-area face is referred to as a front face285and a large-area face is referred to a rear face286. The rear face286of the wedge280is provided to be flat roughly. The wedge280is inserted into the shaft140(seeFIG. 4) to let its front face285look toward the inner ring240.

A distance d2between the first stage284aand the second stage284bincreases with the pressure applied to an outside surface of the wedge280. If the distance d2increases, a diameter d1of the third through-hole282also increases. If the distance d2decreases, the diameter d1also decreases. Under the state that there is no external pressure, the diameter d1of the third through-hole282is provided to be larger than a diameter of the shaft140(seeFIG. 4). Under the state that a pressure is externally applied to let the first and second stages284aand284bbe in contact with each other, the diameter d1of the through-hole of the wedge280is provided to be equal to or slightly small than the diameter of the shaft140.

FIG. 9is a perspective view of the pressuring member shown inFIG. 5. Referring toFIGS. 5 and 9, the pressuring member is configured to push a wedge280toward a main body240aof an inner ring240. The pressuring member may include a cap290where formed is a fourth through-hole294a. The fourth trough-hole294ais formed at the center of the cap290. The cap290includes a body292having a space into which a sub-body240bof the inner ring240is inserted and a pressuring wall294provided at the back end of the body292. A screw thread293is formed at an inner circumferential surface of the body292to correspond to the screw threads246that is formed at the sub-body240bof the inner ring240. The fourth through-hole294ais formed at the center of the pressuring wall294, and the shaft140(seeFIG. 4) is inserted into the fourth through-hole294a. If the cap290rotates to be screw-coupled with the inner ring240and moves forward to the main body240a, the pressuring wall294pushes the wedge280inserted into the second through-hole242bof the sub-body240btoward the main body240a.

FIGS. 10 and 11illustrate the steps that a guide unit200is fixed to a shaft140by a fixing member270. First, as illustrated inFIG. 10, the wedge280is inserted into the second through-hole242bof the sub-body240bin a direction where the front face285of the wedge280looks toward the main body240aof the inner ring240. The cap290is screw-coupled with the inner ring240to let the wedge280move toward the main body240ainside the sub-body240b, as illustrated inFIG. 11, if a distance d2between the first stage284aand the second stage284bdecreases and the wedge280moves a predetermined distance, the first and second stages284aand284bcome in contact with each other. Thus, the wedge280is first inserted into the sub-body240bwhile the inside surface283of the wedge280is spaced apart from the shaft140. However, as the wedge280moves toward the main body240a, the inside surface283of the wedge280comes in contact with the shaft140. Thereafter, the shaft140is pressurized to fixedly couple the shaft140with the inner ring240.

Next, a method of assembling and coupling the guide unit200with the shaft140will now be described. Referring toFIG. 6, the outer ring220, the inner ring250, and the bearings260are assembled. The bearing260is inserted into each through-hole252of the retainer ring250. The inner ring240is forcibly inserted into an inner space254of the retainer250to let the retainer250cover the inner ring240. An assembling body of the retainer250and the inner ring240is forcibly into the first through-hole222of the outer ring220. The shaft140is inserted into an assembling body including the inner ring240, the retainer250, the bearing260, and the outer ring220, the wedge280and the cap290to insert the shaft140into the second through-hole242of the inner ring240, the third through-hole282of the wedge280, and the fourth through-hole292of the cap290in the order listed. The cap290is screw-coupled with the sub-body240bof the inner ring240to fix the inner ring240to the shaft140.

FIG. 12illustrates the state where the guide unit200is installed in an opposite direction to shown inFIG. 6. Referring toFIG. 12, similar to the foregoing, the inner ring240, the retainer250, the bearing260, and the outer ring220are assembled. Contrary to the foregoing, the shaft140is sequentially inserted into the cap290and the wedge280. The shaft140is inserted into an assembling body including the inner ring240, the retainer250, the bearing260, and the outer ring220. The cap290is screw-coupled with the sub-body240bof the inner ring240to fix the inner ring240to the shaft140.

Next, modified embodiments according to the present invention will now be described below.

FIG. 13illustrates a modified guide units200′. Referring toFIG. 13, the guide unit200′ includes an inner ring240′ having a different configuration from the foregoing embodiment. The inner ring240′ includes one main body240aand two sub-bodies240bprovided at both sides of the main body240arespectively. Thus, a wedge280and a cap290are more easily coupled with an inner ring240when the guide unit200′ is inserted into a shaft140with the change of install direction.

FIG. 14illustrates another modified guide units200″. Referring toFIG. 14, the guide unit200″ includes an outer ring220″ having a different configuration from the foregoing embodiment. The outer ring220″ includes a guide230extending from the end of its outer circumferential surface in outside direction (radius direction). If an outer circumferential surface224and an inclined surface232of an outer ring232in the guide unit200″ are deteriorated, the outer ring220″ or the guide unit200″ is replaced with new one.

FIG. 15illustrates a modified substrate transporting apparatus20′. While a guide unit according to the foregoing embodiment is installed on a shaft140where a transporting roller120is installed, a guide unit200of the substrate transporting apparatus20′ is fixedly installed at a separate shaft142between shafts140where transporting rollers120are installed.

FIG. 16illustrates a modified substrate transporting apparatus20″. The substrate transporting apparatus20illustrated inFIG. 2transports a substrate S of horizontal state and includes a guide unit200installed at both sides of a shaft140. However, as illustrated inFIG. 16, a shaft140is inclined to transport a substrate S of inclined state. InFIG. 16, the reference numeral “α” denotes an inclined angel of a shaft. The guide unit200is installed at a lower one of both sides of the shaft140.

According to the present invention, the side of a substrate is protected from damage during transportation of the substrate. According to an embodiment of the present invention, the install direction of a guide unit is variable to extend the lifetime of the guide unit. According to another embodiment of the present invention, a guide unit is easily installed because it is fixedly coupled with a shaft where a transporting roller is installed.

Although the present invention has been described in connection with the embodiment of the present invention illustrated in the accompanying drawings, it is not limited thereto. It will be apparent to those skilled in the art that various substitutions, modifications and changes may be made without departing from the scope and spirit of the invention.