Abstract:
A method of fabricating a resistive touch panel, which fixes the problems of the conventional method needing a plurality of screen printing processes, has a combined process of making the barrier and the spacers. The method of the present invention has less screen printing process to lower the cost and increase the production capacity.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates generally to a touch panel, and more particular to a simplified method of fabricating the resistive touch panel. 
         [0003]    2. Description of the Related Art 
         [0004]      FIG. 1  shows a common resistive touch panel  1 , which has, from bottom to top, a bottom conductive substrate  2 , a plurality of insulating spacers  3 , a linear electrode  4 , a first barrier layer  5 , a conductive wire layer  6 , a second barrier layer  7  and a top conductive substrate  8 . 
         [0005]    The bottom conductive layer  2  has a conductive film  2   a , on which the spacers  3  are printed by screen printing. The purpose spacers  3  is to keep a suitable distance between the conductive films  2   a  and  8   a  of the bottom and top conductive substrates  2  and  8  after the touch panel  1  has been assembled that prevent the conductive films  2   a  and  8   a  from short when the touch panel  1  has not been pressed. 
         [0006]    After making the spacers  3 , the linear electrode  4  is made around the spacers  3  by screen printing, and then the first barrier layer  5  is made by screen printing also. The first barrier layer  5  covers the linear electrode  4  and has four through holes  5   a  and a hollow portion  5   b . And then, the conductive wire layer  6  is made on the first barrier layer  5 . As shown in  FIG. 1 , the conductive wire layer  6  consists of five independent wires, so called five-wire resistive touch panel, in which four wire  6   a ,  6   b ,  6   c , and  6   d  are electrically connected to the linear electrode  4  through one through hole  5   a , and the fifth wire  6   e  is are electrically connected to the conductive film  8   a  of the top conductive substrate  8  through a through hole  7   a  of the second barrier layer  7 . The second barrier  7  has a hollow portion  7   b  also. The spacers  3  are received in a space within the hollow portions  5   b  and  7   b  of the first and second barrier layers  5  and  7 . 
       SUMMARY OF THE INVENTION 
       [0007]    The primary objective of the present invention is to provide a duplicator with a reliable, faster and efficient data duplication function. 
         [0008]    According to the objective of the present invention, a method of fabricating a resistive touch panel comprises the steps of: Providing a first conductive substrate, on which a first patterned electrode is provided to define a region on the first conductive substrate. Forming a patterned first insulating layer on the first conductive substrate, wherein the first insulating layer has a barrier covering the first patterned electrode, a plurality of spacers received in the region and a plurality of through holes through the barrier. Providing a second panel and electrically connecting the second panel to the first panel. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an exploded view of the conventional five-wire resistive touch panel; 
           [0010]      FIG. 2  is an exploded view of the five-wire resistive touch panel of a preferred embodiment of the present invention; 
           [0011]      FIG. 3  is a sectional view in combination of  FIG. 2 ; 
           [0012]      FIG. 4  is a flow chart of the first method of fabricating the five-wire resistive touch panel of the preferred embodiment of the present invention; 
           [0013]      FIG. 5  is a flow chart of the second method of fabricating the five-wire resistive touch panel of the preferred embodiment of the present invention; 
           [0014]      FIG. 7  and  FIG. 8  are sectional views of the first barrier layer made by yellow light process; 
           [0015]      FIG. 9  is similar to  FIG. 3 , showing a four-wire resistive touch panel; and 
           [0016]      FIG. 10  is a flow chart of the first method of fabricating a four-wire resistive touch panel. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    As shown in  FIG. 2  and  FIG. 3 , a five-wire resistive touch panel  100  made by a method of the preferred embodiment of the present invention includes a first panel  10  and a second panel  20 . The first panel  10  includes a first conductive substrate  12 , a patterned electrode  14 , a first insulating layer  16  and a second patterned electrode  18 . The second panel  20  includes a second conductive substrate  22  and a second insulating layer  24 . 
         [0018]    The anterior process of making the first panel  10  and the posterior process of making the second panel  20  are described hereunder: 
         [0019]    As shown in  FIG. 4 , the anterior process includes: 
         [0020]    Preparing the first conductive substrate  12 , which consists of a plate  121  and an ITO conductive film  122 . 
         [0021]    Printing metal wires on IOT conductive film  122  by screen printing to form the first patterned electrode  14 , as shown in  FIG. 2 . The first patterned electrode  14  is a closed loop to surround a region  123  on the ITO conductive film  122 . 
         [0022]    Performing another screen printing process to print an insulating material on the first conductive substrate  12  to form the patterned first insulating layer  16  after the insulating material is solidified. The patterned first insulating layer  16  has a barrier  161 , a plurality of spacers  162  and four through holes  163 , wherein the barrier  161  is a rectangular frame covering the first patterned electrode  14 , and the spacers are dots distributing in the region  123 , and the four through holes  163  are located at four corners of the barrier  161  and through the barrier  161 . 
         [0023]    Providing four pads  17  made of silver in the through holes  163  to electrically connect the first patterned electrode  14 . 
         [0024]    Performing the screen printing process again to print five metal wires  181 ˜ 185  on the barrier  161 , which the metal wires  181 ˜ 185  form the second patterned electrode  18 , wherein the first to fourth wires  181 ˜ 184  are electrically conducted with the first patterned electrode  14  through the pads  17 . 
         [0025]    Above steps are the anterior process of making the first panel  10 . The posterior process is hereunder: 
         [0026]    Preparing the second conductive substrate  22 , which consists of a plate  221  and an ITO conductive film  222 . An electrode wire  223  is provided on the ITO conductive film  222 . 
         [0027]    Performing the screen printing process to print an insulating material on the second conductive substrate  22  to form the patterned second insulating layer  24 . The aspect of the second insulating layer  24  is similar to that of the first insulating layer  16 , except that the second insulating layer  24  only has a through hole  241 , in which silver is filled to electrically conduct the fifth wire  185  and the electrode wire  223 . 
         [0028]    After the first panel  10  and second panel  20  have been made by above steps, the following step is coupling the first and second panels  10  and  20  to have the second insulating layer  24  covering the wires  181 ˜ 185 . The wire  185  is electrically connected to the ITO conductive film  222  of the second conductive substrate  22  through the through hole  241  of the second insulating layer  24 . 
         [0029]      FIG. 2  and  FIG. 3  show the touch panel made by above steps. It is noted that the main character of the present invention is providing one screen printing process to fabricate both of the barrier  161  and the spacers  162  at the same time. In view of fabrication, the present invention simplifies the process that benefits in lower cost of fabrication, decrease of defective ratio, shorter time of the process and increase of production capacity etc. 
         [0030]    In above process, the second conductive substrate  22  is made with the second insulating layer  24  prior to couple with the first panel  10 . It is noted that the method of the present invention is not limited in the coupling of the second conductive substrate  22  with the second insulating layer  24  first. In other words, the second insulating layer may be made next to the second patterned electrode  18 , and then the second conductive substrate  22  is coupled with the first conductive substrate  12 , as shown in  FIG. 5 . In addition, in the posterior process, it may further include a step of making the second patterned electrode, and there should be no second patterned electrode made in the anterior process, as shown in  FIG. 6 . 
         [0031]    The method of making the fist insulating layer, except the screen printing process, further includes yellow light process. 
         [0032]    As shown in  FIG. 7 , after the step of making the first patterned electrode  14 , coating a sensitive material on the ITO conductive film  1221  of the first conductive substrate  12 . The sensitive material may be sensitive acrylic resin or sensitive polymer. And then, performing the processes of exposure and development, as shown in  FIG. 8 , the residual patterned photoresist layer is the first insulating layer  16 ′ with the barrier  161 ′, the spacers  162 ′ and the through hole  163 ′. This is another process of making the first insulating layer, and the following steps are as same as the above steps, and they will not be described again. 
         [0033]      FIG. 9  shows a four wire resistive touch panel, which a method of making it includes the same technical character of the present invention, including a first panel  30  and a second panel  40 . The first panel  30  has a first conductive substrate  32 , a first patterned electrode  34  and a first insulating layer  36 . The second panel  40  has a second conductive substrate  42  and a second patterned electrode  44 . The method of making the above touch panel is shown in  FIG. 10 , which includes the steps of making the first and second panels  30  and  40 . 
         [0034]    First, forming the first patterned electrode  34  on the first conductive substrate  32 , and then performing screen printing process to make the first insulating layer  36  on the first conductive substrate  32 . The first insulating layer  36  has a barrier  361 , a plurality of spacers  362  and a plurality of through holes  363 , wherein the barrier  361  covers the first patterned electrode  34 . In the same time, making the second patterned electrode  44  on the second conductive substrate  42 , and then coupling the first and second panels  30  and  40  to electrically connect the second patterned electrode  44  to the first patterned electrode  34  through the through holes  363  of the first insulating layer  36 . To have a well electrical conduction, conductive pads  50  are provided in the through holes  363 , and an adhesive layer  52  is provided between the barrier  361  and the second patterned electrode  44  to keep the first and second panels  30  and  40  with strong coupling. 
         [0035]    The description above is a preferred embodiment of the present invention and the equivalence of the present invention is still in the scope of the claim of the present invention.