Abstract:
An apparatus and method for fabricating a blanket for a printing roll for is provided. The apparatus includes a container to receive and drop printing roll blanket material for patterning an LCD substrates, a preheating part below the container to preheat dropped printing roll blanket material and a curing part below the preheating part to cure preheated printing roll blanket material. The method includes dropping printing roll blanket material for patterning an LCD substrate from a container, preheating the dropped printing roll blanket material and curing the preheated printing roll blanket material.

Description:
This application claims the benefit of priority under 35 U.S.C. § 119 to Korean Patent Application No. P2005-22264, filed on Mar. 17, 2005. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a printing roll used in a printing method, and more particularly, to a blanket which may be adhered to a printing roll. 
     2. Discussion of the Related Art 
     The process of making an LCD or semiconductor device typically involves depositing a plurality of layers and etching the coated layers. In particular, CVD (Chemical Vapor Deposition) and sputtering methods are used to deposit layers, while photolithographic methods are used to etch the coated layers. 
     When forming a plurality of layers, complexities associated with deposition and etching can account for reduced productivity. Therefore, efficient mass production of LCD or semiconductor devices requires more simplified deposition and etching processes. 
     Compared with photolithographic processes for patterning coated layers, patterning processes employing printing are simpler and easier to accomodate. 
     When forming a desired pattern by printing, a predetermined material is coated in a desired pattern on a printing roll. To form the desired pattern on a substrate, the material printed on the printing roll is re-printed on the surface of the substrate by rolling the printing roll on the substrate. Because of their simplicity, patterning methodologies involving printing lend themselves favorably to processes demanding more efficient mass production. 
       FIGS. 1A to 1C  are cross sectional views depicting a printing method according to the related art. As shown in  FIG. 1A , printing material  20  is coated on a printing plate  10  in a predetermined pattern. When a printing roll  30  is rolled on the coated printing plate  10 , the printing material  20  is printed on a blanket  35  disposed on the printing roll  30  ( FIG. 1B ). Then, the printing roll  30  containing the printing material  20  is rolled on a substrate  40  to re-print the printing material  20  thereon. As a result, the printing material  20  is formed in a predetermined pattern on the substrate  40 . 
       FIGS. 2A and 2B  illustrate a process for fabricating a blanket according to the related art. First, a mold  50  having a concave part  55  in a predetermined shape is prepared ( FIG. 2A ). The concave part of the mold  50  is then filled with a resin material used to form the blanket ( FIG. 2B ). To fabricate the blanket  35 , the pressure part  60  applies a predetermined pressure to the resin material in the mold  50 . 
     It is difficult obtain an accurate pattern using such a blanket, however. This may be attributed to imperfections in the concave part  55  when forming the mold  50  and to reduced pressure uniformity when the pressure part  60  is lowered. 
     If the non-uniform blanket is used, a defect may arise when printing the printing material on the blanket.  FIG. 3  illustrates how a defect may be generated when a imperfect blanket  35  is used according to the related art. If, for example, a portion  35   a  of the blanket  35  is protruding, a non-designated portion  20   a  of printing material may be inadvertently printed on the blanket  35 , thereby producing an undesired pattern on a substrate thereafter. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an apparatus and method for fabricating a blanket for a printing roll, which obviate one or more problems in the related art. 
     In one aspect, the present invention provides a method for fabricating a blanket for a printing roll, which includes dropping printing roll blanket material for patterning an LCD substrate from a container; preheating the printing roll blanket material; and curing the printing roll blanket material to form a cured blanket. 
     In a further aspect, the present invention provides an apparatus for fabricating a blanket suitable for a printing roll, where the apparatus includes a container configured to receive printing roll blanket material for patterning an LCD substrate and to drop the printing roll blanket material therefrom; a preheating part below the container, the preheating part configured to preheat dropped printing roll blanket material; and a curing part below the preheating part, the curing part configured to cure preheated printing roll blanket material. The apparatus may further include a rotation roll below the preheating part, where the curing part is positioned along the circumference of the rotation roll. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate aspects and principles of the present invention. 
         FIGS. 1A to 1C  are cross sectional views of a printing method according to the related art. 
         FIGS. 2A and 2B  are schematic views of a process for fabricating a blanket according to the related art. 
         FIG. 3  is a schematic view illustrating the nature of defect obtained using an imperfect blanket according to the related art. 
         FIG. 4  is a schematic view of an apparatus and method for fabricating a blanket according to an embodiment of the present invention. 
         FIG. 5A  is a perspective view of a container according to an embodiment of the present invention,  FIG. 5B  is a cross sectional view along A-A′ of  FIG. 5A ;  FIG. 5C  is a cross sectional view along B-B′ of  FIG. 5A . 
         FIGS. 6A and 6B  are cross sectional views of two containers according to the present invention. 
         FIGS. 7A and 7B  are cross sectional views illustrating a preheating part according to the present invention. 
         FIG. 8  is a schematic view of an apparatus for fabricating a blanket according to a particular embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to embodiments exemplifying the present invention in accordance with the specification, claims and accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
       FIG. 4  depicts an exemplary apparatus for fabricating a blanket according to one embodiment of the present invention. The apparatus includes a container  100 , a preheating part  200 , a rotation roll  300  and a curing part  400 . 
       FIG. 5A  is a perspective view of an exemplary container according to the present invention.  FIG. 5B  is a cross sectional view along A-A′ of  FIG. 5A ;  FIG. 5C  is a cross sectional view along B-B′ of  FIG. 5A .  FIGS. 6A and 6B  are cross sectional views of a container. 
     The container  100  receives blanket material  350  and drops the blanket material  350  therefrom ( FIG. 4 ). The container  100  is provided with a body  120  and a nozzle  140 . The body  120  includes a hole for receiving blanket material  350  and the nozzle  140  includes a slit for dropping the blanket material therefrom to form a blanket. Although the container  100  in  FIGS. 5 and 6  includes one body  120  and one nozzle  140 , the container may include a plurality of bodies  120  and nozzles  140 . 
     The container  100  in  FIG. 5A  includes a body  120 , a nozzle  140 , a supplying tube  160 , and an exhaust tube  180 . The nozzle  140  is provided below the body  120 . The supplying tube  160  supplies the body  120  with blanket material. The exhaust tube  180  exhausts material from the body  120 . 
     The supplying tube  160  is connected to an accommodation groove  125  in which blanket material is supplied. The supplying tube  160  includes a valve  165  controlling the amount of material supplied to the accommodation groove for making the  125  blanket. 
     The exhaust tube  180 , which is connected to an accommodation groove  125  in the body  120 , exhausts material from the accommodation groove  125  to the outside of the container  100  ( FIG. 5A ). The exhaust tube  180  has a valve  185 . 
     It is necessary to periodically clean the container  100 . Before cleaning the container  100 , material remaining in the container  100  may be exhausted to the outside through an exhaust tube  180 . In the course of cleaning the container  100 , detergent remaining therein may be subsequently exhausted through the exhaust tube  180  to the outside. Thus, the exhaust tube  180  can be used to exhaust material and detergent to the outside. 
       FIGS. 5B and 5C  depict an accommodation groove  125  in the body  120  for receiving blanket material. The accommodation groove  125  is connected to a nozzle  140  having a slit  145  for dropping the blanket material down. 
     The size of the slit  145  may be modified to control the flow of blanket material therethrough. For example,  FIG. 5B  depicts a body  120 , including a spacer  150 , a plurality of through holes  162 , and a plurality of bolts  159  and nuts  161  coupled to each through hole  162 . As depicted in  FIG. 5B , the bolts  159  and nuts  162  may be operated to control the size of the slit  145  so as to control the flow of the dropped blanket material. 
     The container may include sub-containers, each having a sub-body  120   a  and  120   b  and a sub-nozzle  140   a  and  140   b  ( FIGS. 6A and 6B ). The accommodation groove  125  in the body  120  may be formed by the connection between two sub-accommodation grooves in sub-bodies  120   a  and  120   b  ( FIG. 6A ) or it may be formed from one sub-accommodation groove in either of sub-bodies  120   a  or  120   b  ( FIG. 6B ). 
     A preheating part  200  below the container  100  preheats dropped material to achieve a predetermined hardness in the blanket material  350   a.  Preferably, the preheating part  200  includes a heater. 
       FIGS. 7A and 7B  depict representative cross sections of the preheating part  200 . In one embodiment, the preheating part  200  may completely surround the blanket material  350  ( FIG. 7A ). Alternatively, the preheating part  200  may be positioned in parallel sides facing the blanket material  350 . 
     Below the preheating part  200  is a rotation roll  300  containing a surface to be coated by the dropped blanket material  350  ( FIG. 4 ). Preferably, the rotation roll  300  has the same size as the printing roll on which a blanket may be adhered. Using a rotation roll identical in size to the printing roll simplifies the process of adhering a blanket to the printing roll. 
     When the blanket material  350  is coated on the surface of the rotation roll  300 , the blanket material  350  may be adhered to the printing roll by a curing and cutting process. In one aspect, a curing part  400  may provided in the circumference of the rotation roll  300 . The curing part  400  cures blanket material  350  coated on the rotation roll  300  ( FIG. 4 ). 
     When using a blanket material  350  that includes thermal curing type material, the curing part  400  may include a heater. On the other hand, when using a blanket material  350  that includes UV curing type material, the curing part  400  may include a UV lamp. 
     Preferably, a cutting part is additionally provided along the circumference of the rotation roll  300 . However, the cutting part is unnecessary when the rotation roll  300  serves as the printing roll. If, however, a separate printing roll is used, a cutting part may be provided to cut the cured blanket material  350  adhered to the rotation roll  300 . 
     The following method may be used to fabricate a blanket with the aforementioned apparatus. First, appropriate blanket material  350  is dropped from the container  100 . Then, the dropped blanket material  350  is preheated and cured to obtain blanket material  350  having a desirable, predetermined hardness. 
     The blanket material  350  may be preheated using a preheating part  200 , coated on the surface of a roll and then cured using a curing part  400 . Preferably, the blanket material is preheated by a preheating part  200  at a temperature between 60° C. and 100° C. 
     The curing process may be varied depending on the type of blanket material  350 . If the blanket material  350  includes thermal curing type material, the blanket material  350  may be cured at a temperature between 120° C. to 140° C. If the blanket material includes UV curing type material, it is preferable to use UV rays from a UV lamp. After the blanket material is cured, it may then be cut. 
       FIG. 8  depicts an apparatus for fabricating a blanket according to another embodiment of the present invention. The apparatus in  FIG. 8  includes a container  100 , a preheating part  200  and a curing part  400  underneath. The container  100 , preheating part  200  and curing part  400  set forth in  FIG. 8  follow the structures and accompanying disclosures above. A cutting part  500  may be additionally included below the curing part  400  as set forth in  FIG. 8 . 
     The process of fabricating a blanket with the apparatus exemplified in  FIG. 8  is similar to the process for fabricating a blanket as already described above. That is, a blanket material  350  is received in the container  100  and then dropped. The dropped blanket material  350  is then preheated using a preheating part  200  cured to a desirable, predetermined hardness. The preheating process of the preheating part  200  may be carried out at a temperature between 60° C. and 100° C. Dropped blanket material  350 , preheated by the preheating part  200 , may then be cured by the curing part  400 . 
     The process of curing by the curing part  400  may be changed depending on the type of blanket material. That is, if the blanket material includes a thermal curing type material, the blanket material may be cured at a temperature between 120° C. and 140° C. If the blanket material includes a UV curing type material, the blanket material may be cured using UV rays from a UV lamp. A cutting process may be utilized to cut the blanket material after completing the curing process. 
     The above described blanket fabrication methodology makes it possible to fabricate a blanket having a more uniform appearance without the defects associated blankets fabricated using molds according to the related art as described above. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the specification and the appended claims and their equivalents.