Abstract:
An IPP resin material capable of improving the adhesive strength between a transparent electrode and an IPP resin layer is disclosed. 
     The IPP resin material includes: a liquid pre-polymer including a mono-functional monomer, a di-functional monomer including a monomer containing an ether group, and a tri-functional monomer including pentaerythritol triacrylate; a photo initiator; and a adhesion promoter, wherein the monomer containing the ether group includes any one of poly (propylene glycol) diacrylate, poly (propylene glycol) dimethacrylate, propylene glycol diacrylate), and tri (ethylene glycol) dimethacrylate.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 U.S.C. 119 to Korean Patent Application No. 10-2008-107106/10-2009-0097051, filed on Oct. 30, 2008 and Oct. 13, 2009, which is hereby incorporated by reference in its entirety. 
       BACKGROUND 
       [0002]    1. Field of the Disclosure 
         [0003]    This disclosure relates to an in-plane printing (IPP) resin layer and a liquid crystal display (LCD) device manufacturing method using the same. 
         [0004]    2. Description of the Related Art 
         [0005]    Recently, thin film transistor and color filter array substrates used in the configuration of LCD devices have adopted an IPP method of pattern formation which, unlike the related art photolithography method. 
         [0006]    The IPP method forms a resin layer for the IPP on a substrate and brings a mold with an embossed/intaglio pattern into contact with the resin layer. Then, a repulsive force is generated by creating a surface energy difference between the IPP resin layer and the mold, and a capillary force is generated by the suction of the IPP resin layer into the embossed/intaglio pattern of the mold. Accordingly, the embossed/intaglio pattern of the mold is transcribed onto the IPP resin layer. In other words, an IPP resin layer pattern corresponding to the intaglio pattern of the mold is formed. 
         [0007]    The IPP method can simplify the manufacturing process and cut down the manufacturing costs of array substrates. Also, the IPP method can form a high definition pattern and in turn improve the productivity of the pattern and array substrates. 
         [0008]    The IPP method mainly uses a resin layer such as a liquid pre-polymer. The resin layer is used for the formation of a pattern, such as a photoresist pattern for a photocopy process. Also, the resin layer is provided as a functional film material such as an overcoat layer, a column spacer, a passivation film, a semi-permeable insulation film, and so on. 
         [0009]    The IPP resin layer including an organic insulation film is often covered with a transparent electrode such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO). However, this results in a poor adhesive strength between the IPP resin layer and the transparent electrode. Therefore, a resin layer which improves the adhesive strength between the IPP resin layer of the organic material and the transparent electrode is necessary. 
       BRIEF SUMMARY 
       [0010]    Accordingly, the present embodiments are directed to an IPP resin layer that substantially obviates one or more of problems due to the limitations and disadvantages of the related art. 
         [0011]    An object of the present embodiment is to provide an IPP resin layer capable of improving the adhesive strength between a transparent electrode and an IPP resin layer of an organic material, and an LCD device manufacturing method using the same. 
         [0012]    Additional features and advantages of the embodiments 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 embodiments. The advantages of the embodiments will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
         [0013]    According to one general aspect of the present embodiment, a resin layer for an IPP process includes: a liquid pre-polymer including a mono-functional monomer, a di-functional monomer including a monomer containing an ether group, and a tri-functional monomer including pentaerythritol triacrylate; a photo initiator; and a adhesion promoter, wherein the monomer containing the ether group includes any one of poly (propylene glycol) diacrylate, poly (propylene glycol) dimethacrylate, propylene glycol diacrylate), and tri (ethylene glycol) dimethacrylate. 
         [0014]    The mono-functional monomer includes any one of diethylene glycol ethylether acrylate, ethylene glycol methylether acrylate which each contain the ether group. 
         [0015]    The mono-functional monomer includes glycidyl methacrylate. 
         [0016]    The mono-functional monomer is at a rate of 5˜50 wt %, the di-functional monomer is at a rate of 10˜30 wt %, the tri-functional monomer is at a rate 20˜40 wt %, the photo initiator is at a rate of 1˜20 wt %, and the adhesion promoter is at a rate of 1˜3 wt %. 
         [0017]    The mono-functional monomer is at a rate of 5˜50 wt %, the di-functional monomer is at a rate of 10˜40 wt %, the tri-functional monomer is at a rate 10˜20 wt %, the photo initiator is at a rate of 1˜20 wt %, and the adhesion promoter is at a rate of 1˜3 wt %. 
         [0018]    A manufacturing method of an LCD device according to another aspect of the present embodiment includes: disposing a soft mold above a substrate which includes an in-plane printed resin layer on it; bringing the soft mold into contact with the in-plane printed resin layer to form a thin film pattern; removing the soft mold from the substrate; and forming a transparent electrode on the substrate which includes the thin film pattern. The in-plane printed resin layer includes a liquid pre-polymer including a mono-functional monomer, a di-functional monomer including a monomer containing an ether group, and a tri-functional monomer including pentaerythritol triacrylate; a photo initiator; and a adhesion promoter, wherein the monomer containing the ether group includes any one of poly (propylene glycol) diacrylate, poly (propylene glycol) dimethacrylate, propylene glycol diacrylate), and tri (ethylene glycol) dimethacrylate. 
         [0019]    The mono-functional monomer includes any one of diethylene glycol ethylether acrylate, ethylene glycol methylether acrylate which each contain the ether group. 
         [0020]    The mono-functional monomer includes glycidyl methacrylate. 
         [0021]    The mono-functional monomer is at a rate of 5˜50 wt %, the di-functional monomer is at a rate of 10˜30 wt %, the tri-functional monomer is at a rate 20˜40 wt %, the photo initiator is at a rate of 1˜20 wt %, and the adhesion promoter is at a rate of 1˜3 wt %. 
         [0022]    The mono-functional monomer is at a rate of 5˜50 wt %, the di-functional monomer is at a rate of 10˜40 wt %, the tri-functional monomer is at a rate 10˜20 wt %, the photo initiator is at a rate of 1˜20 wt %, and the adhesion promoter is at a rate of 1˜3 wt %. 
         [0023]    Other systems, methods, features and advantages will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the following claims. Nothing in this section should be taken as a limitation on those claims. Further aspects and advantages are discussed below in conjunction with the embodiments. It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the disclosure as claimed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The accompanying drawings, which are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the disclosure. In the drawings: 
           [0025]      FIGS. 1A to 1E  are cross-sectional views showing in steps a thin film formation method using an IPP resin layer according to the embodiment of the present disclosure; 
           [0026]      FIG. 2  is a schematic diagram showing the combination of a transparent electrode material and an ether group according to an embodiment of the present disclosure; 
           [0027]      FIGS. 3A to 3D  are cross-sectional views showing in steps a method of manufacturing a transflective thin film transistor array substrate using an IPP resin layer according to the embodiment of the present disclosure; 
           [0028]      FIGS. 4A to 4D  are cross-sectional views showing in steps a method of manufacturing a thin film transistor array substrate using an IPP resin layer according to the embodiment of the present disclosure; and 
           [0029]      FIGS. 5A and 5B  are views explaining the degree of adhesive strength between a transparent electrode and an IPP resin layer. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. The embodiments introduced hereinafter are provided as examples in order to convey their spirits to the ordinary skilled person in the art. Therefore, the embodiments might be embodied in a different shape, so are not limited to the embodiments described here. Also, the size and thickness of the device might be expressed to be exaggerated for the sake of convenience in the drawings. Wherever possible, the same reference numbers will be used throughout this disclosure including the drawings to refer to the same or like parts. 
         [0031]    An IPP resin layer according to an embodiment of the present disclosure includes a monomer containing an ether group and is used as a resin layer (or a thin film). As such, the IPP resin layer may improve the adhesive strength between a transparent electrode and an IPP resin layer. The IPP resin layer with this desired effect, according to the embodiment of the present disclosure, will now be explained in detail. 
         [0032]    The resin layer for the IPP resin layer of the present embodiment includes a liquid pre-polymer, a photo initiator, and an adhesion promoter, among other components. 
         [0033]    The liquid pre-polymer may include a monomer containing an ether group. More specifically, the liquid pre-polymer includes a mono-functional monomer, a di-functional monomer, and a tri-functional monomer. 
         [0034]    In the case of compounding the liquid pre-polymer, the mono-functional monomer and the di-functional monomer can be used as the monomer containing the ether group. Alternatively, only the di-functional monomer can be employed as the monomer containing the ether group. 
         [0035]    If the mono-functional monomer and the di-functional monomer are used as the monomer containing an ether group, the mono-functional monomer may include any one of DEGEEA (diethylene glycol ethylether arcylate) and EGMEA (ethylene glycol methylether acrylate), which each contain an ether group. Likewise, the di-functional monomer containing an ether group may include any one of PPGDA (poly (propylene glycol) diacrylate), PPGDMA (poly (propylene glycol) dimethacrylate), PGDA (propylene glycol diacrylate), and TEGDMA (tri (ethylene glycol) dimethacrylate). 
         [0036]    On the other hand, when only the di-functional monomer is used as the monomer containing an ether group, the mono-functional monomer may include GMA (glycidyl methacrylate) and the di-functional monomer may include any one of PPGDA (poly (propylene glycol) diacrylate), PPGDMA (poly (propylene glycol) dimethacrylate), PGDA (propylene glycol diacrylate), TEGDMA (tri-(ethylene glycol) dimethacrylate). 
         [0037]    The tri-functional monomer may include PETIA (pentaerythritol triacrylate). 
         [0038]    GMA is a chemical compound indicated by the following Chemical Formula 1. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0039]    EGMEA is a chemical compound indicated by the following Chemical Formula 2. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0040]    DEGEEA is a chemical compound indicated by the following Chemical Formula 3. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0041]    PPGDA is a chemical compound indicated by the following Chemical Formula 4. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0042]    PPGDMA is a chemical compound indicated by the following Chemical Formula 5. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0043]    PGDA is a chemical compound indicated by the following Chemical Formula 6. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0044]    TEGDMA is a chemical compound indicated by the following Chemical Formula 7. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0045]    PETIA is a chemical compound indicated by the following Chemical Formula 8. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0046]    The photo initiator may include “2-carbonethoxy ethyltrimethoxysilane” or another component. 
         [0047]    Also, the IPP resin layer of the present embodiment can be compounded to include the mono-functional monomer of 5˜50 wt %, the di-functional monomer of 10˜40 wt %, the tri-functional monomer of 10˜40 wt %, the photo initiator of 1˜20 wt %, and the adhesion promoter of 1˜3 wt %. In this case, it is preferable for the PETIA with a viscosity of about 100 cP to be included in the resin layer because the PPGDA has a viscosity of about 30 cP. 
         [0048]    Alternatively, if the di-functional monomer includes any one of PPGDA, PPGDMA, PGDA, and TEGDMA, the di-functional monomer included in the resin layer corresponds to an amount of about 10˜40 wt %. In this case, the tri-functional monomer, which contains PETIA, included in the resin layer becomes an amount of about 10˜20 wt %. 
         [0049]    Alternatively, when the di-functional monomer includes any one of PPGDA, DEGEEA, EGMEA, PPGDMA, PGDA, and TEGDMA, the di-functional monomer included in the resin layer becomes an amount of about 10˜30 wt %. At the same time, the tri-functional monomer of PETIA included in the resin layer corresponds to an amount of about 20˜40 wt %. 
         [0050]    As described above, the IPP resin layer of the present embodiment includes the monomer containing an ether group. Accordingly, the IPP resin layer can improve the adhesive strength between the transparent electrode and an IPP resin layer. 
         [0051]    Hereinafter, methods of forming a desired thin film and manufacturing a flat panel display device (i.e., an LCD device) through the IPP process using the IPP resin layer will be explained. 
         [0052]      FIGS. 1A to 1E  are cross-sectional views explaining in steps a thin film formation method using the IPP resin layer according to an embodiment of the present disclosure. 
         [0053]    A soft mold  20  including an embossed or intaglio pattern on it is disposed above a substrate  10  coated with an IPP resin layer  12   a . The IPP resin layer  12   a  is formed of the resin layer including a liquid pre-polymer, a photo initiator, an adhesion promoter, and additive. The liquid pre-polymer includes a monomer containing an ether group. 
         [0054]    The soft mold  20  is in contact with the IPP resin layer  12   a , as shown in  FIG. 1B . 
         [0055]    As such, part of the IPP resin layer  12   a  is sucked into the intaglio portion of the soft mold  20 , as shown in  FIG. 1C . The IPP resin layer  12   a  is hardened through a heat hardening process or a UV hardening process, thereby forming a thin film pattern  12   b  on the substrate  10 . 
         [0056]    Then, the soft mold  20  is removed from the substrate  10  with the thin film pattern  12   b , as shown in  FIG. 1D . 
         [0057]    As shown in  FIG. 1E , a transparent electrode material such as indium-tin-oxide or indium-zinc-oxide, is formed on the substrate  10  including the thin film pattern  12   b  and is patterned, so that a transparent electrode  14  is formed. 
         [0058]    When the transparent electrode material is deposited on the substrate  10  with the thin film pattern  12   b  of the IPP resin layer through a sputtering process, indium included in the transparent electrode material reacts with the ether group (—O—) contained in the IPP resin layer, as shown in  FIG. 2 . Accordingly, the IPP resin layer pattern  12   b  has an adhesive strength more intense than that of the related IPP resin layer. 
         [0059]    In this manner, as the IPP resin layer including the monomer containing an ether group is used for the IPP resin layer, the adhesive strength between the transparent electrode and the IPP resin layer pattern (i.e., the thin film pattern  12   b ) can be improved. 
         [0060]      FIGS. 3A to 3D  are cross-sectional views showing in steps a method of manufacturing a transflective thin film transistor array substrate using an IPP resin layer according to an embodiment of the present disclosure. 
         [0061]    Referring to  FIG. 3A , a gate electrode  102  is formed on a substrate  100  and a gate insulation film  104  is formed on the entire surface of the substrate  100  with the gate electrode  102 . An active/ohmic contact layer  106  and source/drain electrodes  108   a / 108   b  are formed on the gate insulation film. The active/ohmic contact layer  106  and the source/drain electrodes  108   a / 108   b  can be formed through a single masking process or a double masking process. 
         [0062]    A first protective film  110  used as an insulation film and an IPP resin layer  112   a  and a second protective (or passivation) film are sequentially formed on the substrate with the above structure. The first protective film  110  is an inorganic insulation film such as a silicon nitride film or a silicon oxide film. The IPP resin layer  112   a  used for the second protective film is formed of the IPP resin layer including a liquid pre-polymer, a photo initiator, an adhesion promoter, and so on, as described above. The liquid pre-polymer includes a monomer containing an ether group. 
         [0063]    Also, a soft mold  101  including an embossed or intaglio pattern on it is disposed above a substrate  100  coated with an IPP resin layer film  112   a . The soft mold  101  has a surface layer which includes concaves  101   a  for forming an embossed pattern, a first convex portion  101   b  for forming a contact hole which exposes the drain electrode, and a second convex portion  101   c  for forming a penetration portion. 
         [0064]    The soft mold  101  is in contact with the IPP resin layer  112   a , as shown in  FIG. 3B . As such, part of the IPP resin layer  112   a  is filled up the concaves  101   a  and first convex portions  101   b  and second convex portions  101   c  of the soft mold  101 . The IPP resin layer  112   a  is formed the second protective film  112   b  on the substrate  100  by hardening through a heat hardening process or a UV hardening process. This second protective film  112   b  includes a contact hole  111   b , a penetration hole  111   a  for the formation of a penetration portion, and an embossed pattern. 
         [0065]    As shown in  FIG. 3C , the soft mold  101  is removed from the substrate  100  on which that the second protective film  112   b  including a contact hole  111   b , a penetration hole  111   a  for the formation of a penetration portion, and an embossed pattern is formed. 
         [0066]    Next, as shown in  FIG. 3D , a transparent electrode material such as indium-tin-oxide or indium-zinc-oxide is formed on the entire surface of the substrate  100 , which includes the thin film pattern  112   b , and is patterned, so that a pixel electrode  114  is formed on a reflection region R and a penetration region T. The pixel electrode  114  is formed in a rugged structure along the embossed pattern of the second protective film. Also, the pixel electrode  114  is connected to the drain electrode  108   b  through the contact hole  111   b.    
         [0067]    The transparent electrode material of the pixel electrode is deposited on the second protective film  112   b , which includes the contact hole  111   b , the penetration hole  111   a  of the pixel region, and the embossed pattern. When this transparent electrode material is deposited through a sputtering process, indium components included into the transparent electrode material react with the ether group (—O—) contained in the IPP resin layer. Accordingly, the second protective film  112   b  of the IPP resin layer has an adhesive strength more intense than that of the related IPP resin layer. 
         [0068]    Finally, a metal material for a reflection electrode  116  is formed and patterned on the transparent electrode  114 , so that the reflection electrode  116  is provided on the reflection region R. In the end, a transflective thin film transistor array substrate may be provided. 
         [0069]    In this way, as the IPP resin layer including the monomer containing an ether group is used for the IPP resin layer, the adhesive strength between the transparent electrode and the IPP resin layer (i.e., the second protective layer  112   b ) can be improved. 
         [0070]      FIGS. 4A to 4D  are cross-sectional views showing in steps a method of manufacturing a thin film transistor array substrate using an IPP resin layer according to an embodiment of the present disclosure. 
         [0071]    Referring to  FIG. 4A , a gate electrode  202  is formed on a substrate  200  and a gate insulation film  204  is formed on the entire surface of the substrate  200  with the gate electrode  202 . An active/ohmic contact layer  206  and source/drain electrodes  208  are formed on the gate insulation film  204  above the gate electrode  202 . The active/ohmic contact layer  206  and the source/drain electrodes  208  can be formed through a single masking process or a double masking process. 
         [0072]    An IPP resin layer  212   a  for a protective (or passivation) film is formed on the substrate  200  with the above structure. In this case, an additionally protective film (not shown) including an inorganic insulation film such as a silicon nitride film or a silicon oxide film can be formed before the formation of the IPP resin layer  212   a . The IPP resin layer  212   a  used for the protective film is formed of the IPP resin layer including a liquid pre-polymer, a photo initiator, an adhesion promoter, and additive, as described above. The liquid pre-polymer includes a monomer containing an ether group. 
         [0073]    Also, a soft mold  102  including a fixed intaglio pattern on it is disposed above a substrate  200  coated with an IPP resin layer  212   a . The soft mold  101  includes on its surface a convex portion  201   a  for a contact hole exposing the drain electrode. 
         [0074]    The soft mold  102  is in contact with the IPP resin layer  212   a , as shown in  FIG. 4B . As such, the convex portion  201   a  of the soft mold  102  forms a contact hole in the IPP resin layer  212   a . The IPP resin layer  212   a  is hardened through a heat hardening process or a UV hardening process, so that the second protective film  212   b  including a contact hole  211   a  is formed on the substrate  200 . 
         [0075]    As shown in  FIG. 4C , the soft mold  102  is removed from the substrate  200  on which the protective film  212   b  including a contact hole  211   a  is formed. 
         [0076]    Next, a transparent electrode material such as indium-tin-oxide or indium-zinc-oxide is formed on the entire surface of the substrate  200 , which includes the protective film  212   b , and is patterned, thereby forming a pixel electrode  214  as shown in  FIG. 4D . In the end, a thin film transistor array substrate may be provided. The pixel electrode  214  is connected to the drain electrode  208  through the contact hole  211   a.    
         [0077]    When the transparent electrode material for the pixel electrode  214  is deposited on the protective film  212   b  which includes the contact hole  211   a  through a sputtering process, indium components included in the transparent electrode material react with the ether group (—O—) contained in the IPP resin layer. Accordingly, the protective film  212   b  of the IPP resin layer has an adhesive strength more intense than that of the related IPP resin layer. 
         [0078]    In this way, as the IPP resin layer which includes the monomer containing the ether group is used for the IPP resin layer, the adhesive strength between the transparent electrode and the IPP resin layer (i.e., the protective film  212   b ) can be improved. 
         [0079]      FIGS. 5A and 5B  are views proving the degree of adhesive strength between a transparent electrode and an IPP resin layer. In order to check the degree of adhesive strength between the transparent electrode and the IPP resin layer, the peeling degree of the transparent electrode is experimentally observed after wet-etching the transparent electrode formed on the IPP resin layer during a fixed period.  FIG. 5A  shows the peeling degree of the transparent electrode on the IPP resin layer according to the related art.  FIG. 5B  depicts the peeling degree of the transparent electrode on the IPP resin layer according to the present embodiment. As seen in  FIG. 5A , broken portions (or disconnected portions) of the transparent electrode exist within a dotted line circuit. Accordingly, the transparent electrode on the related art IPP resin layer is easily peeled. On the contrary, the transparent electrode on the IPP resin layer according the present embodiment has no the broken portions (or disconnected portions), as shown in  FIG. 5B . Consequently, it is evident that the transparent electrode on the IPP resin layer according the present embodiment is resistant to peeling (or difficult to peel). 
         [0080]    Furthermore, the peeling degree of the transparent electrode in accordance with the wet-etching period is measured as the following table 1. 
         [0000]    
       
         
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                 IPP resin layer 
                 IPP resin layer 
               
               
                 Wet-etching period 
                 (related art) 
                 (present embodiment) 
               
               
                   
               
             
             
               
                 3 Minutes 
                 1.14 μm 
                 0.99 μm 
               
               
                 5 Minutes 
                  1.7 μm 
                 1.31 μm 
               
               
                   
               
             
          
         
       
     
         [0081]    As described in table 1, the peeled length of the transparent electrode on the IPP resin layer according to the present embodiment is shorter than that on the IPP resin layer of the related art. In other words, it is evident that the transparent electrode on the IPP resin layer according the present embodiment is difficult to peel. 
         [0082]    As described above, the IPP resin layer according to an embodiment of the present disclosure which includes the monomer containing an ether group is used for the IPP resin layer. Therefore, the adhesive strength between the transparent electrode and the IPP resin layer including the IPP resin layer can be improved. 
         [0083]    Although the present disclosure has been limitedly explained regarding only the embodiments described above, it should be understood by the ordinary skilled person in the art that the present disclosure is not limited to these embodiments, but rather that various changes or modifications thereof are possible without departing from the spirit of the present disclosure. Accordingly, the scope of the present disclosure shall be determined only by the appended claims and their equivalents.