Abstract:
An air curtain system for forming an air curtain dividing two processing spaces and for spraying air on to a substrate to remove any impurities remaining on the substrate includes an air supplier, a main body having an air inlet passage for receiving air from the air supplier, an air flow space defined within the main body and communicating with the inlet passage, and a slit extending from the air flow space to spray the air on the substrate, and a substantially strip-shaped rectifying lattice provided with a plurality of openings located at an equal distance from each other. The lattice is positioned within the air flow space.

Description:
CROSS REFERENCE TO RELATED ART 
     This application claims priority of Korean Patent Application No. 98-32967 filed on Oct. 14, 1998, the entire disclosure of which is hereby incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an air curtain system used in manufacturing a thin film transistor-liquid crystal display (“TFT-LCD”), and more particularly, to an air curtain system for constantly spraying air or N 2  gas on an LCD substrate to remove a solution remaining after such solution is used for removing a photoresist, the photoresist being used for patterning an electrode of the LCD. 
     2. Description of the Related Art 
     FIG. 1 illustrates, in cross-section view, a portion of a glass substrate as it undergoes sequential processing steps for forming an electrode such as an indium tin oxide (ITO) electrode thereon. 
     An electrode-forming layer  102  is first deposited on a glass substrate  101 , after which the glass substrate  101  is cleaned using a cleaning solution. Next, a photoresist  103  is deposited on the electrode-forming layer  102 , and exposed to a light using a photo mask  104  to obtain a desirably patterned photoresist  103   a  through a developing process. 
     Following the above steps, the electrode forming layer  102  is etched using the patterned photoresist  103   a  as a mask, then the patterned photoresist  103   a  is removed through a stripping process, thereby obtaining a desirably patterned electrode  112 . 
     In the stripping process, a photoresist may remain on the glass substrate  101  and the patterned electrode  112 , and is removed using a stripping solution which is sprayed at a high pressure on the glass substrate  101 . 
     After this step, to clean away the stripping solution, the substrate  101  is conveyed to an air curtain system. 
     FIGS. 2 and 3 show a conventional air curtain system. 
     An air curtain system  105  includes a front plate  105   a  and a rear plate  105   b , between which a space  109  is defined. A slit  108  having a clearance of 0.1 mm extends downward from the space  109 . Two air suppliers  110  for supplying air to the space  109  are symetrically mounted on the front plate  105   a.  An air tube  107  is connected to the air supplier  110 . The air or N 2  gas is supplied from the air tube  107  to the space  109  through a passage  106  formed in the air supplier  110 . The air supplied to the space  109  is sprayed on the substrate  101  through the slit  108  in order to remove the remaining stripping solution. 
     At this point, the air sprayed through the slit  108  further functions as a curtain for blocking fumes which are generated during processing of a downstream substrate. 
     However, as shown in FIG. 3, since the air on N 2  gas supplied from the two air suppliers  108  is sprayed directly toward the substrate through the slit  108  without any obstruction, the air pressure difference may occur between three portions of the slit  108  corresponding to regions R 1 , R 2  and R 3 , respectively. Therefore, the air curtain system having the structure described above has a drawback in that, since the air pressure is not uniform throughout the slit  108 , the stripping solution remaining may not be completely removed. In addition, if the air pressure is increased to completely remove the remaining stripping solution, the substrate and the electrode may be damaged. 
     SUMMARY OF THE INVENTION 
     In order to overcome the problems described above, preferred embodiments of the present invention provide an air curtain system which effectively removes a stripping solution which is used to remove a remaining photoresist material used in patterning an electrode of an LCD, while effectively blocking fumes generated during processing of a substrate in a downstream process. 
     According to one preferred embodiment of the present invention, an air curtain system is constructed to form an air curtain which divides two processing spaces and sprays air onto a substrate to remove any impurities remaining on the substrate. The air curtain system preferably includes an air supplier, a main body having an air inlet passage for receiving air from the air supplier, an air flow space defined within the main body and communicating with the inlet passage, and a slit extending from the air flow space to spray the air on the substrate, an air distributing means supported within and across the gas flow space downstream from the gas inlet passage, the air distributing means distributing the gas to be sprayed uniformly toward the substrate through the slit; and an impurity removing means for primarily removing impurities from the substrate, the impurity removing means mounted on the main body and arranged before the slit, whereby the impurities on the substrate are sequentially removed by the impurity removing means and the gas sprayed from the slit of the main body. 
     The main body preferably includes a front plate and a rear plate which is coupled on a rear side of the front plate, the air inlet passage extending through the front plate, the air flow space and the slit being defined between the front and rear plates. 
     Preferably, the main body may include a clearance adjusting bolt for coupling the front and rear plates and adjusting the clearance of the slit. 
     According to a preferred embodiment of the present invention, the air regulator may include a substantially strip-shaped rectifying lattice fixed on the front and rear plates within the air flow space, the rectifying lattice being provided with a plurality of openings, each opening equidistantly spaced from the two adjacent opening. 
     Preferably, the air curtain system further includes a balance adjusting unit which is arranged to adjust a balance of the system. The balance adjusting unit preferably includes a pair of brackets mounted substantially symmetrically on a top of the main body and a pair of screws positioned on the brackets. 
     Preferably, the air curtain system further includes an impurity removing unit which is constructed and arranged to remove impurities from the substrate before the impurities on the substrate are removed by the air sprayed from the main body. The impurity removing unit is preferably mounted on the front plate. 
     The impurity removing unit preferably includes a supporting bar mounted on the front side of the air supplier and extending downward, a plate mounted on a lower end of the supporting bar, and a knife member integrally connected in a substantially perpendicular manner relative to a lower side of the plate and substantially parallel to the substrate to be treated. 
     Preferably, the supporting bar has a longitudinal hole to adjust a height of the knife member, the longitudinal hole being slidably coupled to a guide bolt which is integrally formed on a front surface of the air supplier. 
     Preferably, the knife member is provided at its extreme end with a solution-removing blade for effectively removing excessive solution which is remaining on the substrate. 
     Other elements, features, advantages and components of preferred embodiments of the present invention will be described in further detail with reference to the drawings attached hereto. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the present invention, and, together with the description, serve to explain the principles of the present invention: 
     FIG. 1 illustrates, in cross-section, a portion of an LCD substrate as it undergoes sequential processing steps for being patterned; 
     FIG. 2 is a schematic sectional view illustrating a conventional air curtain system; 
     FIG. 3 is a front view of the conventional air curtain system of FIG. 2; 
     FIG. 4 is a sectional view of an air curtain system according to a preferred embodiment of the present invention; 
     FIG. 5 is a front view of the air curtain system shown in FIG. 4; and 
     FIG. 6 is an enlarged perspective view illustrating a rectifying lattice depicted in FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 
     Certain terminology will be used in the following description for convenience and reference only, and will not be limiting. The words “front”, “rear”, “upper” and “lower” will designate directions in the drawings to which reference is made. 
     Referring first to FIG. 4, an air curtain system according to a preferred embodiment of the present invention includes a main body B having a front plate  2  and a rear plate  3  coupled to a rear side of the front plate  2 . Symmetrically mounted on a front side of the front plate  2  are two air suppliers  4 . The front plate  2  has located at its rear surface at least two front horizontal grooves  7 , and  8  and has located at its rear lower surface, a slanted portion  10 . The front plate  2  further includes at its rear upper side, a projection  11  extending in a rearward direction. The projection  11  defines a space  5  between the front plate  2  and the rear plate  3 . In one example of a preferred embodiment of the present invention, the space  5  is generally defined and constructed so as to have a volume of about 24.8 cm 3 , for example. 
     The front plate  2  is further provided with a passage  13  which is located upstream from the front horizontal grooves  7 . The passage  13  is arranged to communicate with a connecting passage  12  of the air supplier  4 . 
     A plurality of gap adjusting bolts  14  are provided on the rear plate  3  to adjust a dimension or volume of the space  5 . The rear plate  3  has at its front surface rear horizontal grooves  8  corresponding to the front horizontal grooves  7 . Rectifying lattices  9  are fixed in the front and rear horizontal grooves  7  and  8 . 
     Each of the rectifying lattices  9 , as shown in FIG. 6, preferably includes a substantially strip-shaped member which has a thickness of about 1 mm and a width of about 6.5 mm, for example. A plurality of openings  17  are formed in each of the rectifying lattices  9 . Preferably, the openings  17  are equidistantly spaced away from one another. for example, about 9 mm. Each of the openings  17  has a diameter of, for example, about 3.5 mm. 
     Therefore, as the horizontal grooves  7  and  8  are arranged downstream from the passage  13  communicating with the connecting passage  12  of the air supplier  4 , the air fed through the passages  12  and  13  passes through the openings  17  formed in the rectifying lattices  9 . In addition, since the openings  17  are spaced equidistantly from one another the flow rate of the air passing the air curtain system  1  becomes constant. In other words, the air on N 2  gas from air sources (not shown) is supplied to the two air supplies  4  symmetrically arranged and spaced apart from each other, and then air or N 2  gas from the two air suppliers  4  in supplied to the space  5  through the two passages  13 . At this point, the air pressure in the space  5  at the two air suppliers  4  is relatively high, while the air pressure in the space  5  between the two air suppliers  4  is relatively low. However, the air N 2  gas from the two passages  13  is passed through the space  5  by two rectifying lattices  9  having a plurality of the openings  17  such that the air N 2  gas passing through the two rectifying lattices  9  is distributed uniformly regardless of the position of the air supplier and sprayed toward the substrate through the slit  15 . 
     The air or N 2  gas passing through the rectifying lattices  9  is sprayed toward the substrate  101 , on which the electrode  112  is formed, via a slit  15  defined between the front slanted portion  10  disposed on the rear lower surface of the front plate  2  and a rear slant  16  disposed on the front lower surface of the rear plate  3 . The slit  15  has a clearance t 1  of, for example, about 0.1 mm such that an air curtain is formed while the air passes through the slit  15 . 
     In the above described preferred embodiment, although the rectifying lattices  9  are preferably substantially strip-shaped, this is not limiting of the present invention. That is, the rectifying lattice  9  can be substantially rectangular or substantially rod-shaped. In addition, more than three rectifying lattices can be provided. 
     In addition, the clearance of the slit  15  can be adjusted according to the level of air pressure to be supplied. This is achieved by the gap adjusting bolt  14 . That is, by adjusting the gap adjusting bolt  14  in a state where a limit gauge (not shown) is inserted into the slit  15 , the clearance of the slit  15  can be adjusted easily and accurately. 
     In addition, the width of the space  5  between the front and rear plates  2  and  3  is preferably less than about 6.5 mm as the width of the rectifying lattice  9  is preferably about 6.5 mm. 
     Preferably, two screws  18  (shown in FIGS. 4 and 5) are further provided to balance the air curtain system  1  mounted on a supporter  30 . As shown in FIG. 4, the screws, being spaced apart from one another, are mounted on a pair of brackets  19  which are. symmetrically mounted on the main body B defined by the front and rear plates  2  and  3 . Each of the screws  18  includes a measuring rod  18   a,  a lower end of which contacts the supporter  30  to be fixed. Each screw  18  is adjustable in an up-and-down direction separately and, therefore the balance of the air curtain system  1  is controlled precisely and a distance between the slit  15  and the substrate  101  can also be controlled. 
     Therefore, the air curtain system  1  is precisely balanced within about 0.01 mm or less by the screws  18  and can be fixed by a connector such as bolts (not shown). 
     The air curtain system  1  further includes a pre-treatment member  6  for primarily removing the remaining solution before it is removed by the air sprayed from the main body B, the pre-treatment member  6  being mounted on the front side of the air supplier  4  and adjustable in an up-and-down direction. 
     As shown in FIG. 5, the pre-treatment member  6  preferably includes a pair of supporting bars  21  mounted on the front side of the air supplier  4  and extending downward, a plate  20  mounted on a lower end of the supporting bars  21 , and a knife member  24  integrally formed substantially perpendicular to a lower side of the plate  20  and substantially parallel to the substrate to be treated. Each of the supporting bars  21  has longitudinal holes  22  to adjust a height of the knife member  24 . The knife member  24  is provided at its extreme end with a solution-removing blade  25  for removing excessive remaining solution on the electrode  112 . 
     Therefore, the remaining solution is first removed as the substrate  101  is conveyed to the air curtain system  1  in a direction indicated by an arrow in FIG.  4 . That is, the remaining solution existing above a clearance t 2  (see FIG. 4) is first removed by the blade  25  of the knife member  24 , then the rest of the remaining solution is removed by the air sprayed through the main body B. 
     The knife member  24  is preferably triangle-shaped to effectively remove the remaining solution. 
     In addition, because of the presence of the knife member  24 , the amount of solution that should be removed by the main body B can be small, thus, the possibility of contaminating other portions such as the treated part of the substrate is greatly reduced. If the amount of the solution that the main body should dry is relatively large, the solution blown by the main body B can be splashed about and can contaminate the treated substrate  101   a  or the treated electrode  109   a.    
     Referring to FIGS. 4 and 5, to fix the pre-treatment member  6  on the air supplier  4 , a limit gauge (not shown) is positioned in the clearance t 2  between the knife member  24  and the substrate  101  in a state where guide bolts  23 , integrally formed on the air supplier  4  and slidably positioned in the longitudinal holes  22  formed in the supporting bars  21 , are released. 
     Accordingly, the clearance t 2  between the knife member  24  and the substrate  101  is adjusted in a state where the knife member  24  is supported by the substrate  112  through the limit gauge. 
     Next, by bolting the bolts  23  tightly, thereby fixing the position of the longitudinal holes  22  formed on the air supplier  4  using nuts (not shown), a height of the pretreatment member  6  with respect to the substrate  101  can be precisely adjusted. 
     While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.