Abstract:
A method of preventing seal damage in LCD panel manufacturing. A photo spacer pattern made of photoresist is used instead of extra seal pattern, such that tact time of sealing process is reduced, air blockage is enhanced, the number of TFT-array areas able to be formed on a glass substrate is increased, and chipping or unevenness of the panel resulting during panel cutting owing to extra seal patterns are all avoided.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to the field of LCD panel manufacturing. More particularly, the invention relates to a method for preventing seal damage in ODF LCD panel manufacturing.  
           [0003]    2. Description of the Related Art  
           [0004]    One Drop Fill (ODF) process has become a new form of LCD panel manufacturing. FIG. 1 shows an equipment currently used for ODF LCD panel manufacture. The equipment may be a press machine having an upper chuck  14  and a lower chuck  15  in a vacuum chamber  13 , wherein at least one of the chucks is movable. The equipment may also be provided with an image recognition camera (not illustrated). The operation of the equipment as illustrated in FIG. 1 is described hereinafter. First, one substrate  12  is held by the lower chuck  15 , and the other substrate  11  is held by the vacuum formed of the upper chuck  14 . Then, after decreasing the air pressure inside the vacuum chamber  13  to a predetermined vacuum level; alignment of the upper side substrate  11  and the lower side substrate  12  is performed to a predetermined accuracy referring to the alignment marks (not shown) by a rotational member  16 , and pressure is applied to the chucks  14  and  15  until the gap between the two substrates reaches a predetermined thickness, and the chamber  13  is brought to atmospheric air pressure through an air-removal hole  17 .  
           [0005]    However, to prevent disadvantages that might occur owing to the sudden change in pressure such as damage to the seals, unevenness of gap thickness, and even contamination of liquid crystal and LCD active areas, an extra seal pattern  22  is usually applied along the periphery of the substrate  21  as shown in FIG. 2, one or two seal patterns  24  are usually applied on the outer side of the original seal pattern  23 , and a cross seal pattern  25  is applied between each TFT-array area to block air entry that might destroy the TFT-array areas when the seal pattern  23  is damaged.  
           [0006]    The above methods to prevent damage to the seal patterns still have shortcomings, for example, a longer time is required to apply the extra seal patterns, thus increasing the tact time of LCD panel manufacture; the seal patterns are not cured from the change in pressure such that the air blockage is not high sufficient and bubbles may occur. Furthermore, application of a seal pattern must usually maintain a minimum distance of about 10 mm from other seal patterns to maintain best performance, therefore, too many seal patterns on the substrate can limit the number of TFT-array areas that can be formed thereon and may also cause chipping, breaking the substrate.  
         SUMMARY OF THE INVENTION  
         [0007]    Therefore, the purpose of the invention is to provide a method of preventing seal damage in LCD panel manufacturing, in which photo spacer of photoresist is used instead of extra seal patterns.  
           [0008]    Thus, the invention provides a method of preventing seal damage in LCD panel manufacturing, comprising providing a pair of substrates, forming a plurality of TFT-array areas on a surface of one of the substrates and forming at least one seal pattern along the periphery of each TFT-array area, forming at least one photo spacer pattern of photoresist along the periphery of the substrates, and aligning the substrates.  
           [0009]    The invention further provides a method of preventing seal damage in LCD panel manufacturing, further comprising a step of forming at least one seal pattern along the periphery of the substrate to increase the adhesion between the substrates.  
           [0010]    Using photo spacer instead of extra seal patterns can decrease tact time and provide sufficient air blockage without performing further curing steps. Furthermore, application of photo spacer can relieve the limitation imposed by extra seal patterns on the number of TFT-array areas that can be formed on the substrate, and also avoid chipping by strengthening the substrate. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    The following detailed description, given by way of example and not intended to limit the invention solely to the embodiments described herein, will best be understood in conjunction with the accompanying drawings, in which:  
         [0012]    [0012]FIG. 1A shows an equipment used for conventional ODF LCD panel manufacture.  
         [0013]    [0013]FIG. 2 shows the seal pattern applied in conventional ODF LCD panel manufacturing.  
         [0014]    [0014]FIG. 3 a  shows the photo spacer pattern and seal pattern applied in the first embodiment of the present invention.  
         [0015]    [0015]FIG. 3 b  shows the photo spacer pattern and seal pattern applied in the second embodiment of the present invention.  
         [0016]    [0016]FIG. 3 c  shows the photo spacer pattern and seal pattern applied in the third embodiment of the present invention.  
         [0017]    [0017]FIG. 3 d  shows the photo spacer pattern and seal pattern applied in the fourth embodiment of the present invention.  
         [0018]    [0018]FIG. 3 e  shows the photo spacer pattern and seal pattern applied in the fifth embodiment of the present invention.  
         [0019]    [0019]FIG. 3 f  shows the photo spacer pattern and seal pattern applied in the sixth embodiment of the present invention.  
         [0020]    [0020]FIG. 3 g  shows the photo spacer pattern and seal pattern applied in the seventh embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]    The method of preventing seal damage in LCD panel manufacturing is explained by the first to seventh embodiments described below, wherein the conventional manufacturing method of photo spacers is applied in which photo resists were exposed, developed, and then etched to form photo spacers. The photo resists applied can be either negative or positive type, and of any photo-resistive materials.  
         [0022]    First Embodiment:  
         [0023]    In FIG. 3 a,  before alignment of a pair of substrates in a vacuum chamber  13  as shown in FIG. 1, a seal pattern  33  is formed on the substrate  31  along the periphery of the TFT-array area  32 , and a photo spacer pattern  34  of photoresist is formed along the periphery of the substrate  31 . Alignment of the substrate  31  and the other substrate (not shown) is then performed to a predetermined accuracy referring to the alignment marks (not shown). Pressure is applied to the chucks  14  and  15  until the gap between the substrates reaches a predetermined thickness, and the chamber  13  is brought to atmospheric air pressure.  
         [0024]    Second Embodiment:  
         [0025]    In FIG. 3 b,  before the alignment of a pair of substrates in a vacuum chamber  13  as shown in FIG. 1, a seal pattern  33  is formed on the substrate  31  along the periphery of the TFT-array area  32 , a photo spacer pattern  34  of photoresist is formed along the periphery of the substrate  31 , and a cross photo spacer pattern  35  is formed between each TFT-array area  32  to avoid large-scale damage to all TFT-array areas when one TFT-array area is damaged. Substrate  31  and the other substrate (not shown) are aligned to a predetermined accuracy referring to the alignment marks (not shown). Pressure is then applied to the chucks  14  and  15  until the gap between the substrates reaches a predetermined thickness, and the chamber  13  is brought to atmospheric air pressure.  
         [0026]    Third Embodiment:  
         [0027]    In FIG. 3 c,  before the alignment of a pair of substrates in a vacuum chamber  13  as shown in FIG. 1, a seal pattern  33  is formed on the substrate  31  along the periphery of the TFT-array area  32 , a photo spacer pattern  34  of photoresist is formed along the periphery of the substrate  31 , and a cross photo spacer pattern  35  is formed between each TFT-array area  32  to avoid large-scale damage to all TFT-array areas when one TFT-array area is damaged. Next, a seal pattern  36  is formed along the outer periphery of photo spacer pattern  34  to increase the adhesion between the substrates. The substrate  31  and the other substrate (not shown) are then aligned to a predetermined accuracy referring to the alignment marks (not shown), and pressure is applied to the chucks  14  and  15  until the gap between the substrates reaches a predetermined thickness, and the chamber  13  is brought to atmospheric air pressure.  
         [0028]    Fourth Embodiment:  
         [0029]    In FIG. 3 d,  before the alignment of a pair of substrates in a vacuum chamber  13  as shown in FIG. 1, a seal pattern  33  is formed on the substrate  31  along the periphery of the TFT-array area  32 , a photo spacer pattern  34  of photoresist is formed along the periphery of the substrate  31 , and a seal pattern  36  is formed along the outer periphery of photo spacer pattern  34  to increase the adhesion between the substrates. Next, a photo spacer pattern  38  is formed along the outer periphery of seal pattern  33  to prevent damage to the seal from the change in pressure. The substrate  31  and the other substrate (not shown) are then aligned to a predetermined accuracy referring to the alignment marks (not shown), and pressure is applied to the chucks  14  and  15  until the gap between the substrates reaches a predetermined thickness, and the chamber  13  is brought to atmospheric air pressure.  
         [0030]    Fifth Embodiment:  
         [0031]    In FIG. 3 e,  before the alignment of a pair of substrates in a vacuum chamber  13  as shown in FIG. 1, a seal pattern  33  is formed on the substrate  31  along the periphery of the TFT-array area  32 , a photo spacer pattern  34  of photoresist is formed along the periphery of the substrate  31 , and a cross photo spacer pattern  35  is formed between each TFT-array area  32  to avoid large-scale damage to all TFT-array areas when one TFT-array area is damaged. Next, a seal pattern  36  is formed along the outer periphery of photo spacer pattern  34  to increase the adhesion between the substrates. Next, a photo spacer pattern  38  is formed along the outer periphery of seal pattern  33  to prevent damage to the seal from the change in pressure. The substrate  31  and the other substrate (not shown) are then aligned to a predetermined accuracy referring to the alignment marks (not shown), and pressure is applied to the chucks  14  and  15  until the gap between the substrates reaches a predetermined thickness, and the chamber  13  is brought to atmospheric air pressure.  
         [0032]    Sixth Embodiment:  
         [0033]    In FIG. 3 f,  before the alignment of a pair of substrates in a vacuum chamber  13  as shown in FIG. 1, a seal pattern  33  is formed on the substrate  31  along the periphery of the TFT-array area  32 , a photo spacer pattern  34  of photoresist is formed along the periphery of the substrate  31 , and a seal pattern  36  is formed along the outer periphery of photo spacer pattern  34  to increase the adhesion between the substrates. Next, a photo spacer pattern  37  is formed along the inner periphery of seal pattern  33  to avoid contamination of TFT-array areas. Next, a photo spacer pattern  38  is formed along the outer periphery of seal pattern  33  to prevent damage to the seal from the change in pressure. The substrate  31  and the other substrate (not shown) are then aligned to a predetermined accuracy referring to the alignment marks (not shown), and pressure is applied to the chucks  14  and  15  until the gap between the substrates reaches a predetermined thickness, and the chamber  13  is brought to atmospheric air pressure.  
         [0034]    Seventh Embodiment:  
         [0035]    In FIG. 3 g,  before the alignment of a pair of substrates in a vacuum chamber  13  as shown in FIG. 1, a seal pattern  33  is formed on the substrate  31  along the periphery of the TFT-array area  32 , a photo spacer pattern  34  of photoresist is formed along the periphery of the substrate  31 , and a cross photo spacer pattern  35  is formed between each TFT-array area  32  to avoid large-scale damage to all TFT-array areas when one TFT-array area is damaged. Next, a seal pattern  36  is formed along the outer periphery of photo spacer pattern  34  to increase the adhesion between the substrates. Next, a photo spacer pattern  37  is formed along the inner periphery of seal pattern  33  to avoid contamination of TFT-array areas. Next, a photo spacer pattern  38  is formed along the outer periphery of seal pattern  33  to prevent damage to the seal from the change in pressure. The substrate  31  and the other substrate (not shown) are then aligned to a predetermined accuracy referring to the alignment marks (not shown), and pressure is applied to the chucks  14  and  15  until the gap between the substrates reaches a predetermined thickness, and the chamber  13  is brought to atmospheric air pressure.  
         [0036]    When the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.