Patent Document

[0001]    The present invention claims the benefit of Korean Patent Application No. P2002-27182 filed in the Republic of Korea on May 16, 2002, which is hereby incorporated in its entirety by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates to a liquid crystal display, and more particularly to a liquid crystal display and a fabricating method thereof wherein a spacer is positioned for keeping a cell gap.  
           [0004]    2. Description of the Related Art  
           [0005]    Generally, a liquid crystal display (LCD) controls the light transmittance of each liquid crystal cell in response to a video signal. Accordingly, a picture is displayed corresponding to the video signals on an LCD panel having liquid crystal cells arranged in a matrix. To this end, the LCD panel includes an active area having liquid crystal cells arranged in a matrix and driving circuits for driving the liquid crystal cells in the active area.  
           [0006]    Referring to FIG. 1, a conventional LCD includes an upper plate consisting of a black matrix  20 , a color filter  16 , a common electrode  14  and an upper alignment film  12  that are sequentially provided on the upper substrate  11 . The conventional LCD also includes a lower plate consisting of a lower substrate  1  on which a thin film transistor (TFT)  25 / 6 / 26 / 27 / 28 / 30 , a pixel electrode  22  and a lower alignment film  10  are sequentially provided. In addition, the conventional LCD includes a spacer  24  and a liquid crystal (not shown) provided between the upper plate and the lower plate.  
           [0007]    In the lower plate, the TFT includes a gate electrode  25  connected to a gate line (not shown), a source electrode  28  connected to a data line (not shown), and a drain electrode  30  connected, via a contact hole  23 , to the pixel electrode  22 . Further, the TFT includes a gate insulating film  6  for insulating the gate electrode  25 , and an active semiconductor layer  26  on the gate insulating film  6  for creating a conductive channel between the source electrode  28  and the drain electrode  30  when a gate voltage is applied to the gate electrode  25 . As shown in FIG. 1, ohmic semiconductor layers  27  are provided between the active layer  26  and the source/drain electrodes  28  and  30  and doped with an impurity for ohmic contacts between the active semiconductor layer  26  and the source electrode  28 , and between the active semiconductor layer  26  and the drain electrode  30 .  
           [0008]    When a gate signal is applied to the gate line of the TFT, a data signal from a data line can be switched through the TFT to the pixel electrode  22 . As a result, the liquid crystal is rotated by means of a voltage difference between a data signal applied to the pixel electrode  22  via the TFT and a common voltage Vcom applied to a common electrode  14 . Accordingly, light transmission quantity through the liquid crystal is determined by the arrangement of the liquid crystal.  
           [0009]    The pixel electrode  22  is positioned at an area adjacent to the intersection of a data line and a gate line, and is made from a transparent conductive material having a high light transmittance. The pixel electrode  22  is provided on a protective film  8  that is on the surface of the lower substrate  1 , and is electrically connected, via a contact hole  23  in the protective film  8 , to the drain electrode  30 . An upper portion of the lower substrate  1 , provided with the pixel electrode  22 , is coated with an alignment film  10  that is subjected to a rubbing process, which completes the assembly of the lower plate.  
           [0010]    The black matrix  20  of the upper plate is formed on the upper substrate  11  in correspondence with the TFT area of the lower plate and an area adjacent to the intersection of a gate line and a data line. The black matrix  20  also defines a liquid crystal cell area in which a color filter  16  will be formed. Further, the black matrix  20  plays a role in preventing light leakage and absorbing an external light such that contrast can be enhanced. The color filter  16  is formed in the cell area as defined by the black matrix  20 . The color filter  16  specifically transmits a wavelength of light for a certain color, such as red, green or blue. The common electrode  14  is formed on the color filter  16 . An indium-tin-oxide (ITO) with good light transmittance is used as the common electrode  14 . Typically, indium-tin-oxide has a hydrostatic property of being hydrophobic. The alignment film  12  is formed by coating an alignment material, such as polyimide, on the common electrode  14  and by performing a rubbing process thereon.  
           [0011]    Ball spacers, like ball spacer  24 , are sprinkled onto either one of the upper plate or the lower plate of the LCD panel by means of a jet nozzle to keep a gap between the upper plate and the lower plate.. The ball spacers should be uniformly distributed for the purpose of keeping a uniform cell gap of the LCD panel. However, it is difficult to uniformly distribute ball spacers due to the randomness in any sprinkling system. If the ball spacers are not uniformly distributed in the LCD panel, the cell gap in individual liquid crystal cells may not be uniform such that a stain-like appearance phenomenon is created in one or more areas on the LCD panel. In addition, if a user applies a pressure to the screen at the exterior of the LCD panel when ball spacers are used, a ripple phenomenon can occur in which the picture on the LCD panel has darkened areas shaped like waves. The darkened wave-shaped areas occur because the ball spacers have been shifted around between the upper plate and the lower plate.  
           [0012]    Recently, there has been a study to provide a spacer that is fixed and patterned at a specific location to overcome the disadvantages of the ball spacer  24  and its sprinkling system. Hereinafter, a manufacturing method of the pattern spacer will be described with reference to FIGS. 2A to  2 C and FIG. 3. More particularly, FIGS. 2A to  2 C are cross-sectional views showing a process of manufacturing a conventional pattern spacer, which will be described in conjunction with FIG. 3, which is a flow chart.  
           [0013]    A spacer material  42   a , as shown in FIG. 2A is coated onto a substrate  40 , as referred to in step S 31  of FIG. 3. The substrate  40  can be either one of the upper plate or the lower plate provided with the TFT. The spacer material  42   a  is a material that is mixed with a solvent, a binder, a monomer and a photo-initiator. As referred to in step S 32  of FIG. 3, the spacer material  42   a  is subject to a pre-curing to eliminate a solvent within the spacer material  42   a , thereby making the spacer material  42   a  into a paste-like state.  
           [0014]    Subsequently, as shown in FIG. 2B, a photo mask  44  having a transmission part  44   a  and a shielding part  44   b  is aligned on the spacer material  42   a . As referred to in step S 33  of FIG. 3, when an ultraviolet (UV) ray is radiated onto the spacer material  42   a  through the photo mask  44 , the spacer material corresponding to the transmission part  44   a  is exposed to the ultraviolet ray.  
           [0015]    As shown in FIG. 2C and referred to in step S 34  of FIG. 3, the spacer material  42   a  is patterned. When the spacer material  42   a  is developed using a negative process, the spacer material  42   a  that is not exposed to the ultraviolet ray is removed while the spacer material that is exposed to the ultraviolet ray is left. When the spacer material  42   a  is developed using a positive process, the spacer material  42   a  that is exposed to the ultraviolet ray is removed while the spacer material that is not exposed to the ultraviolet ray is left. As referred to in step S 35  of FIG. 3, the spacer material  42   a  patterned in this manner is cured to form spacers  42  having a desired height.  
           [0016]    The spacers  42  for keeping a cell gap in the LCD can occupy about 20% of the entire area in a liquid crystal cell. If the spacer  42  is formed by the above-mentioned photolithography technique, then more than 95% of the coated spacer material  42   a  is wasted as a result of a spin-coating process of the photolithographic spacer material. Thus, the conventional photolithography wastes a lot of material in forming the spacer  42  and is inconvenient in that it requires a complex five-step process.  
           [0017]    To reduce the waste of material and the number of process step, there has been a spacer formation method suggested using an ink-jet device as shown in FIGS. 4A to  4 C. As shown in FIG. 4A, an ink-jet device  50  is aligned to correspond to a formation position of the spacer  58 . In this alignment state, ink from the ink-jet device  50  is jetted to the substrate  40 . The substrate  40  corresponds to at least one of the upper and lower plates of a LCD panel. The ink-jet device  50  jets ink using a thermal system or a piezoelectric system. Typically, the latter system is used. The ink-jet device  50  using the piezoelectric system consists of a vessel  52  for containing a material to be jetted, and an inkjet head  54  for jetting a material from the vessel  52 .  
           [0018]    The vessel  52  is filled with the spacer material  58 , and the ink-jet head  54  is provided with a piezoelectric device and a nozzle  56  for jetting the spacer material  58  from the vessel  52 . When a voltage is applied to the piezoelectric device, then a physical pressure is generated to cause a capillary phenomenon in which a flow path between the vessel  52  and the nozzle  56  repeatedly contracts and relaxes. Due to this capillary phenomenon, the spacer material  58  jets out of the nozzle  56  onto the substrate  40 , as shown in FIG. 4A. Then, a curing process is used that exposes the spacer material  58  on the substrate  40  to an ultraviolet ray from a light source (not shown). Thus, the spacer material  58  can be hardened into a spacer  59 , as shown in FIG. 4B.  
           [0019]    Since the spacer material  58  has a hydrostatic property of being hydrophilic, the spacer  49  does not have good adhesion with the common electrode  14  that is also hydrophobic. Although the spacer may have a minimum height for keeping the cell gaps between the upper plate and the lower plate of the LCD panel, the lack of adhesion between the spacer and a plate of the LCD panel enables the spacers to move around.  
         SUMMARY OF THE INVENTION  
         [0020]    Accordingly, the present invention is directed to a liquid crystal display and a fabricating method thereof that obviates one or more of the problems due to limitations and disadvantages of the related art.  
           [0021]    An object of the present invention is to provide a liquid crystal display device and a fabricating method thereof wherein the adhesion of a spacer is increased to prevent a spacer from moving around within an LCD panel.  
           [0022]    Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.  
           [0023]    To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, an embodiment of the invention for a liquid crystal display includes an upper substrate, a lower substrate, a liquid crystal layer between the upper and lower substrates, a transparent electrode including of at least two layers of transparent material provided on at least one of the upper and lower substrates and a spacer material jetted onto the transparent electrode by an ink-jet system, wherein the spacer material has a hydrostatic property different from one of the at least two layers of the transparent electrode.  
           [0024]    In another embodiment, a liquid crystal display device includes an upper substrate, a lower substrate, a liquid crystal layer between the upper and lower substrates, a material layer with a surface that has a surface area with a first hydrostatic property and a spacer jetted onto the material layer by an ink-jet system and having a second hydrostatic property different from the first hydrostatic property.  
           [0025]    In another embodiment, a liquid crystal display device includes an upper substrate, a lower substrate, a liquid crystal layer between the upper and lower substrates, a material having a first hydrostatic property provided on at least one of the upper and lower substrates and a spacer between the upper and lower substrates having a second hydrostatic property different from the first hydrostatic property.  
           [0026]    In another embodiment, a method of fabricating a liquid crystal display device includes the steps of forming a transparent electrode by depositing at least two transparent material layers on at least one of an upper and lower substrates, jetting a spacer material onto the transparent electrode by an ink-jet system, wherein the spacer material has a hydrostatic property different from one of the at least two layers of the transparent electrode, and providing a liquid crystal between the upper and lower substrates.  
           [0027]    In another embodiment, a method of fabricating a liquid crystal display device includes the steps of treating a surface area of a material layer to change the hydrostatic property of the surface area, jetting a spacer material onto the surface area with an ink-jet system and providing a liquid crystal on the material layer.  
           [0028]    In another embodiment, a method of fabricating a liquid crystal display device includes the steps of providing a material having a first hydrostatic property on a substrate, jetting a spacer material with a second hydrostatic property onto the material on the substrate with an ink-jet system; and providing a liquid crystal on the substrate.  
           [0029]    Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly point out in the written description and claims hereof as well as the appended drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]    The accompanying drawings, which are included to provide further understanding of the invention and are incorporated in and constitute part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principals of the invention.  
         [0031]    [0031]FIG. 1 is a cross-sectional view showing a structure of a conventional liquid crystal display.  
         [0032]    [0032]FIG. 2A to FIG. 2C are cross-sectional views representing a process of manufacturing a conventional pattern spacer.  
         [0033]    [0033]FIG. 3 is a flow chart representing the spacer manufacturing method shown in FIG. 2.  
         [0034]    [0034]FIG. 4A and FIG. 4B depict a conventional spacer manufacturing method employing an ink-jet system.  
         [0035]    [0035]FIGS. 5A to  5 C depict a method of fabricating a liquid crystal display employing an ink-jet system according to an embodiment of the present invention.  
         [0036]    [0036]FIG. 6A represents the contact angle of water to a hydrophobic surface of a single ITO layer of a conventional art device.  
         [0037]    [0037]FIG. 6B represents contact angle of water to a hydrophilic surface of multiple ITO layers in accordance with the present invention.  
         [0038]    [0038]FIGS. 7A to  7 C depict a method of fabricating a liquid crystal display according to a second embodiment of the present invention.  
         [0039]    [0039]FIGS. 8A to  8 C depict a method of fabricating a liquid crystal display according to a third embodiment of the present invention.  
         [0040]    [0040]FIGS. 9A to  9 D depict a method of fabricating a liquid crystal display according to a fourth embodiment of the present invention.  
         [0041]    [0041]FIGS. 10A to  10 B depict a method of fabricating a liquid crystal display according to a fifth embodiment of the present invention.  
         [0042]    [0042]FIGS. 11A to  11 B depict a method of fabricating a liquid crystal display according to a sixth embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0043]    Referring to FIGS. 5A to  5 C, a liquid crystal display (LCD) according to a first embodiment of the present invention includes a black matrix  74  provided on an upper substrate  70  to define a cell area, a color filter  72  provided on the cell area defined by the black matrix  74 , a common electrode  77  provided on the color filter  72  and made of a plurality of transparent electrode layers  77 , and a spacer  88  jetted on the top layer  76  of the multiple layer common electrode  77  with an ink-jet device  80 .  
         [0044]    The black matrix  74  defines a cell area in which the color filter  72  is formed, and prevents light leakage and absorbs external light to thereby enhance picture contrast. The color filter  72  is formed in the cell area defined by the black matrix  74 . The color filter  72  transmits a specific wavelength of light color, such as red, green or blue. The multiple layer common electrode  77  includes a plurality of transparent electrode layers, each of which is formed of, for example, indium-tin-oxide (ITO) that has good light transmittance and good conductivity. The top surface electrode layer  76  or upper layers of the multiple layer common electrode  77  have relativly less light transmittance and less conductivity than the lower layers. However, the top surface electrode layer  76  or upper layers have the hydrostatic property of being hydrophilic as opposed to the lower layers, which are hydrophobic.  
         [0045]    Hereinafter, a method of fabricating a liquid crystal display according to the present embodiment will be described with reference to FIGS. 5A to  5 C. First, as shown in FIG. 5A, a black matrix  74 , a color filter  72  and a multiple layer common electrode  77  are provided on an upper substrate  70 . While depositing the ITO material in forming layers of the multiple layer common electrode  77 , the O 2  gas input into the deposition process of the ITO is increased as each layer is deposited so that the top surface electrode layer has a hydrophilic property. The O 2  gas changes a hydrostatic property of the ITO material in that the ITO is changed form hydrophobic to hydrophilic as the O 2  gas concentration is increased. Thus, the resulting top layer  76  of the multiple layer common electrode  77  has a hydrophilic property. The hydrostatic property of the ITO material is changed without reducing the resistivity or transmittance of the multiple layer common electrode  77  significantly as a whole.  
         [0046]    Next, as shown in FIG. 5B, after an inkjet device  80  is aligned at a position corresponding to the black matrix  74 , a spacer material  88  is jetted onto the multiple layer common electrode  77 . The ink-jet device  80  includes a vessel  82  for containing the spacer material  88  to be jetted, and an ink-jet head  84  for jetting the spacer material from the vessel  82 . The vessel  82  is filled with the spacer material  88 , and the ink-jet head  84  is provided with a piezoelectric device and a nozzle  86  for jetting the spacer material  88  contained in the vessel  82 . When a voltage is applied to the piezoelectric device, a physical pressure is generated on the spacer material  88  caused by a capillary phenomenon in which the flow path between the vessel  82  and the nozzle  86  repeatedly contracts and relaxes. Due to this capillary phenomenon, the spacer material  88  is-jetted through the nozzle  86 .  
         [0047]    A hydrostatic property of the spacer material  88  is that it is hydrophobic. Since the spacer material  88  has a hydrophobic property and the top surface layer  76  of the multiple layer common transparent electrode  77  has a hydrophilic property, adhesion between the top transparent electrode layer  76  and the spacer material  88  increased. Thus, the subsequently cured spacer will not easily separate from the top transparent electrode layer  76  or move around.  
         [0048]    The hydrostatic property of a conventional common electrode  78 , that is a single layer, will be explained in reference to FIGS. 6A and 6B by comparison to the multiple layer common electrode  77  according to the embodiment of the present invention. As shown in FIG. 6A, if water (H 2 O) is dropped on the conventional single-layer common electrode  78 , then a contact angle of water with respect to the ITO film is about 50°. Since the conventional common electrode  78  has a hydrophobic property while water has a hydrophilic property, a contact angle is large.  
         [0049]    On the other hand, as shown in FIG. 6B, if water is dropped on the multiple layer common electrode  77  according to the embodiment of the present invention, a contact angle of water with respect to the top surface common electrode layer  76  becomes about 27°. This is because the top surface common electrode layer  76  has a hydrophilic property as a result of increasing the O 2  gas injection into the deposition process for each ITO layer as each layer is deposited until the top surface electrode layer has a hydrophilic property. Since the top surface electrode layer  76  is hydrophilic, the multiple layered common electrode  77  attracts or mixes well with water.  
         [0050]    [0050]FIGS. 7A to  7 C show a method of fabricating a liquid crystal display according to a second embodiment of the present invention. Referring to FIG. 7A, a film  94  having a hydrophobic surface is provided on a substrate  92 . For example, the substrate can be the upper plate or lower plate of an LCD panel. The film  94  can be an ITO film. In the alternative, the film  94  can be an organic film or inorganic film, for example, silicon nitride (SiN x ) used on portions of an ITO film or in lieu of the ITO film to create surface areas having a hydrophobic surface. For example, the film  94  can be an inorganic or organic film on portions of the lower plate of an LCD in which the pixel electrode is not present. The surface of the film  94  is subjected to an O 2  or H 2  plasma treatment, thereby changing the hydrostatic property of the surface of film  94  from a hydrophobic property to a hydrophilic property. In the alternative, the surface of the film  94  can be changed to have a hydrophilic property by utilizing an acid solution treatment, a basic solution treatment, an ion beam treatment or an ultraviolet ray treatment instead of the O 2  or H 2  plasma treatment.  
         [0051]    Subsequently, as shown in FIG. 7B, an ink-jet device  80  is aligned to a black matrix (not shown) under the ITO film of the upper plate of an LCD panel or to an area of the lower plate of an LCD panel in which the pixel electrode is not present. Then the spacer material  90  is jetted onto the film  94 . If the spacer material  90  has a hydrophobic property and is jetted onto the film  94  having a surface with a hydrophilic property, then the contact angle between the film  94  and the spacer material  90  will be increased, as shown in FIG. 7C. The increased contact angle increases the height of the spacer while minimally increasing the width of the spacer for obtaining a specified cell gap with increased aperture. Subsequently, a solvent within the spacer material  90  is evaporated through a curing process to harden the spacer material  90  into a spacer.  
         [0052]    [0052]FIGS. 8A to  8 C show a method of fabricating a liquid crystal display according to a third embodiment of the present invention. Referring to FIG. 8A, a material  122  having a hydrophilic property is coated onto a substrate  120 . In an alternative, an ink-jet device can be used to coat the substrate  120  with the material  122  for good adhesion. The substrate  120  can be an upper plate or a lower plate of the liquid crystal display panel.  
         [0053]    Next, as shown in FIG. 8B, an ink-jet device  126  is aligned on the substrate at a position on which a spacer is to be formed. Then, a spacer material  124  is jetted onto the substrate  120 . The spacer material  124  has a hydrostatic property of being hydrophobic.  
         [0054]    As shown in FIG. 8C, the spacer material  124  jetted from the ink-jet device  126  that is positioned upon the hydrophilic material  122  of the substrate  120 . Since the spacer material  124  is a hydrophobic material, the hydrophilic material  122  repulses the spacer material to thereby enlarge a contact angle between the hydrophobic spacer  124  and the hydrophilic material  122 . Accordingly, a formation height of the spacer  124  is more enlarged than the prior art, so that it becomes possible to easily make the spacer  124  corresponding to a desired suitable height of the cell gap. Thus, when the hydrophobic spacer material is dropped onto a hydrophilic material after the hydrophilic material was coated on the substrate  120 , it becomes possible to set a height of the spacer.  
         [0055]    [0055]FIGS. 9A to  9 D show a method of fabricating a liquid crystal display according to a fourth embodiment of the present invention.  
         [0056]    First, as shown in FIG. 9A, an ink-jet device  134  is aligned on a substrate  130  to drop a hydrophilic material  132  in correspondence with a spacer area. The substrate  130  may be an upper plate or a lower plate of the liquid crystal display panel. The hydrophilic material  132  jetted from the ink-jet device  134  is formed to be spread somewhat widely on the substrate  130  for good adhesion, as shown in FIG. 9B.  
         [0057]    Next, after curing the hydrophilic material  132 , the ink-jet device  134  in which a hydrophobic spacer material  136  is contained is aligned to jet the hydrophobic spacer material  136  onto said hydrophilic material  132 , as shown in FIG. 9C. The hydrophobic spacer material  136  does not necessarily need to undergo a curing process. Because the spacer material  136  is a hydrophobic material having a property repulsing from the hydrophilic material  132 , it can be formed at a larger height or with a greater contact angle than in the related art. In other words, the hydrophobic spacer material  136  is positioned upon the hydrophilic material  132  as shown in FIG. 9D to thereby enlarge a contact angle between the spacer  136  and the hydrophilic material  132 . Accordingly, a formation height of the spacer  136  can be set to a desired suitable height for the cell gap. For example, a formation height of the spacer  136  can be approximately 3 to 5 μm. Thus, when the hydrophobic spacer material is dropped onto a hydrophilic material after the hydrophilic material was dropped on the substrate  130 , it becomes possible to set a height of the spacer.  
         [0058]    [0058]FIG. 10A and FIG. 10B show a method of fabricating a liquid crystal display according to a fifth embodiment of the present invention. Referring to FIGS. 10A and 10B, an ultraviolet ray or an ion beam is radiated on, or a plasma treatment is performed on the surface of a material layer  100  corresponding to a surface area  100   a  at which a spacer is to be formed. To provide the spacer on the material layer  100  of the upper plate in correspondence with the black matrix area or to an area of the lower plate of an LCD panel in which the pixel electrode is not present, and to provide a suitable height of a cell gap, a ratio of a height of the spacer extending from the upper plate to a width of the spacer on the upper plate should be sufficiently large to maintain the aperture and contrast of the LCD panel. To increase the height to width ratio of the jetted spacer, the contact angle should be large. However, if a contact angle between the spacer material and the surface of the substrate  100  is too large, then the spacer may be easily separated from the substrate  100  even though the spacer is formed on the substrate  100 . For the purpose of preventing separation while increasing the contact angle, an ultraviolet ray is selectively radiated only on a surface area  1   00 a to change the hydrostatic property of a surface of the material layer  100  where a spacer will be positioned, thereby enhancing an adhesive force while increasing the contact angle between the material layer  100  and the spacer.  
         [0059]    More specifically, as shown in FIG. 10A, a mask  102  having light transmitting parts  102   a  and light shielding parts  102   b  arranged alternately is aligned to the material layer  100 . The light transmitting part  102   a  of the mask  102  corresponds to a surface area  100   a  at which a spacer is to be formed while the light shielding part  102   b  corresponds to peripheral material layer area  100   b  on which a spacer will not be formed. Thereafter, an ultraviolet ray or an ion beam is radiated such that the ultraviolet ray or an ion beam passes through the light transmitting part  102   a  and changes a property of the surface area  100   a  of the surface of the material layer  100  to thereby enhance an adhesive force between the spacer and the material layer  100 . On the other hand, an area  100   b  in which an ultraviolet ray is not radiated has a hydrostatic property that repulses the spacer material. In the alternative, the surface property can be changed by a plasma treatment instead of a light treatment. Thus, a surface area  100   a  of the material layer on which spacers will be formed is changed from a hydrophobic property to a hydrophilic property by the surface area treatment. Accordingly, a surface area  100   a  of the material layer  100  has a different hydrostatic property from the peripheral material layer areas  100   b  corresponding to a surface of the material layer  100  other than on which a spacer will be formed.  
         [0060]    Subsequently, as shown in FIG. 10B, a hydrophilic spacer material  106  is jetted onto the surface areas  100   a  through a nozzle of the ink-jet device. Since the hydrophilic spacer material  106  has a hydrostatic property different than the peripheral material layer area  100   b , the spacer material  106  has a large contact angle due to the difference of hydrostatic properties between the peripheral material layer area  100   b  and the spacer material. In addition, the hydrophilic spacer material  106  has good adhesion due to the substrate  100   a  and the spacer material  106  having the same hydrostatic property.  
         [0061]    [0061]FIGS. 11A and 11B show a method of fabricating a liquid crystal display according to a sixth embodiment of the present invention. Referring to FIG. 11A and FIG. 11B, an ultraviolet ray or an ion beam is radiated on or a plasma treatment is performed on peripheral material layer areas  116   b  other than surface areas  116   a  at which spacers are to be formed. To increase the height to width ratio of the jetted spacer, the contact angle should be large. However, if a contact angle between the spacer material and the surface of the material layer  116  is too large, the spacer may be easily separated from the material layer  116 . For the purpose of preventing separation while increasing the contact angle, an ultraviolet ray is selectively radiated only on peripheral material layer area  116   b  other than surface areas  116   a  at which spacer are to be formed, thereby enhancing an adhesive force while increasing the contact angle between the material layer  116  and the spacer.  
         [0062]    More specifically, as shown in FIG. 11A, a mask  110  having a light shielding part  110   a  and a light transmitting part  110   b  arranged alternately is aligned to the material layer  116 . The light transmitting part  110   b  of the mask  110  corresponds to an peripheral material layer area  116   b  other than a surface area at which the spacer is to be formed while the light shielding part  110   a  corresponds to a surface area  116   a  at which the spacer is to be formed.  
         [0063]    Thereafter, an ultraviolet ray or an ion beam is radiated. The ultraviolet ray or ion beam passing through the light transmitting part  110   b  changes a surface property of said peripheral material layer area  116   b , thereby changing the surface of the material layer  116  to have a large contact angle. In the alternative, the surface property can be changed by a plasma treatment instead of a light or ion beam treatment. On the other hand, the surface area  116   a  onto which the ultraviolet ray is not radiated has an advantage in that an adhesive force is increased between the spacer and the material layer  116 . Thus, the surface area  116   a  of the surface on material layer  116  has a hydrostatic property different from the peripheral material layer area  116   b.    
         [0064]    Subsequently, as shown in FIG. 11B, a hydrophilic spacer material  112  is jetted onto the surface area  116   a  by means of the ink-jet device  104 . Since the surface area  116   a  and the peripheral material layer area  116   b  have a different surface property from each other, a spacer material  112  jetted from the ink-jet device  104  is formed only at the spacer formation area  116   a . Thus, the hydrophilic spacer material  112  is formed to be higher than the related art, so that the height of the spacer  11   2  increases relative to its width. Therefore, the spacer material  112  has good adhesion to the material layer  116 . Accordingly, it becomes possible to easily take the spacer  112  corresponding to a desired suitable height for a cell gap in an LCD panel.  
         [0065]    As described above, according to the present embodiment, a hydrostatic property of the substrate on which the spacer is formed is made different from that of the spacer material. Accordingly, the spacer can be formed with good adhesion, is formed at a large height owing to a repulsion force between the substrate and the spacer. In other words, it is possible to more easily obtain a height for a spacer having good adhesion to a substrate for maintaining cell gap while also maintaining aperture size for the cells of a LCD panel.  
         [0066]    It will be apparent to those skilled in the art that various modifications and variations can be made in the apparatus and method for fabricating a liquid crystal display of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Technology Category: 3