Abstract:
A thin touch panel includes a transparent substrate with a black bordering around the inner surface of the transparent substrate. A plurality of metal connecting structures, metal guiding lines, transparent insulating structures and a transparent sensing layer are formed on the inner surface, so that the transparent substrate not only provides a touch surface, but also has the touch sensing ability, to decrease the manufacture material and increase the transmittance of the touch panel. Besides, the manufacture of the thin touch panel may not use any optical adhesive to decrease the manufacture cost and improve the yield. Further, the thin touch panel may satisfy the trend of thin design.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to a capacitive touch panel, and more particularly to a thin touch panel. 
     DESCRIPTION OF THE RELATED ART 
     Most of the existing electronic products such as handheld computer, personal digital assistant (PDA), and information appliance (IA) may be equipped with a touch display screen  10  as illustrated in  FIG. 1 . The touch display screen  10  mainly comprises a capacitive touch module  12  and a display panel  14 . The conventional capacitive touch module  12  comprises a capacitive touch panel  16  and a cover lens  18 . A top surface  181  of the cover lens  18  is capable of being a finger touch region. A black pattern  20  is formed on edges of a bottom surface  182  of the cover lens  18 , and the black pattern  20  is tightly combined with a glass substrate  161  of the capacitive touch panel  16  by sticking an optical adhesive  22 . A sensing circuit layer  162  consisted of a transparent conductive film  163  such as indium tin oxide (ITO), an insulating layer  164  and metal lines  165  is formed on a bottom surface of the glass substrate  161 , which may detect capacitance variations and induced currents caused of the sensing circuit layer  162  being touched, so as to further calculate a coordinate of a position being touched. In addition, a transparent over coat  24  is formed under the sensing circuit layer  162  to protect the sensing circuit layer  162  from being scraped. 
     However, the cover lens  18  and the glass substrate  161  of the capacitive touch panel  16  mentioned above are both made of glass. Thus, more materials may be consumed during manufacturing. In addition, the conventional capacitive touch panel  16  and cover lens  18  are manufactured respectively first and then unitized by stacked up in sequence. However, the assembling process not only more complicated and spends much time, but also increases the total height of the capacitive touch module  12 , thus unable to confirm lighter and thinner requirement of the existing electronic products. Furthermore, since the optical adhesive  22  is much expensive and hard to be stuck well, all the optical adhesive  22 , the capacitive touch panel  16  and cover lens  18  have to be discarded because of unable to be reworked. Thus, these materials are wasted. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a thin touch panel, wherein a black bordering, a transparent sensing layer, a plurality of metal connecting structures, a plurality of metal guiding lines and a plurality of transparent insulators are formed on an inner surface of a transparent substrate directly. Thus, the transparent substrate may not only be a touch end, but also have a touch control ability of thin touch panel directly. Comparing to the conventional touch panel, the glass substrate of the touch panel disposed between the cover lens and the display panel may be simplified, so as to reduce material consumption and increase a transparency of the touch panel. In addition, the process of sticking the cover lens and the glass substrate by using the optical adhesive may be left out, so as to further reduce the cost of the sticking process and enhance the yield rate. Furthermore, the thickness of the whole structure of the touch panel is reduced, so as to benefit a design tendency of thinning out the product. 
     According to an embodiment of the present invention, the thin touch panel comprises a transparent substrate having an outer surface (an upper side of the substrate) and an inner surface (a lower side of the substrate) opposite to one another, the outer surface capable of being a touch end; a black bordering formed on edges of the inner surface (lower side of the substrate) to dispose around a sensing region; a plurality of metal connecting structures arranged as an array and formed on the sensing region, and a plurality of metal guiding lines formed on a surface of the black bordering; a plurality of transparent insulators respectively corresponding to each of the metal connecting structures and respectively covering part of the metal connecting structures, and two opposite ends of the metal connecting structures being exposed; a transparent sensing layer comprising a plurality of first sensing pads arranged on the sensing region as an array, a plurality of transparent conductive connecting structures disposed across surfaces of the transparent insulators to electrically connect the first sensing pads and part of the metal guiding lines along a first direction, a plurality of second sensing pads arranged on the sensing region as an array, and the second sensing pads and part of the metal guiding lines being electrically connected along a second direction by the exposed opposite ends of the metal connecting structures (the second direction is different to the first direction); and a transparent over coat covering the transparent sensing layer, the transparent insulators, the metal connecting structures and the metal guiding lines. 
     According to another embodiment of the present invention, the thin touch panel comprises a transparent substrate having an outer surface (an upper side of the substrate) and an inner surface (a lower side of the substrate) opposite to one another, the outer surface capable of being a touch end; a black bordering formed on edges of the inner surface (lower side of the substrate) to dispose around a sensing region; a transparent sensing layer comprising a plurality of first sensing pads and a plurality of transparent conductive connecting structures formed on the sensing region of the inner surface, and the transparent conductive connecting structures electrically connecting the first sensing pads along a first direction, a plurality of second sensing pads formed on the sensing region adjacent to and isolated from one another and alternately arranged with the first sensing pads, and a plurality of transparent guiding lines formed on a surface of the black bordering, and electrically connected to part of the first sensing pads and part of the second sensing pads; a plurality of transparent insulators respectively covering each corresponding transparent conductive connecting structure, and each transparent insulator crossing on two adjacent ends of two isolated second sensing pads; a plurality of metal connecting structures respectively formed on each transparent insulator, and electrically connecting the second sensing pads along a second direction (the second direction is different to the first direction); a plurality of metal guiding lines formed on the transparent guiding lines; and a transparent over coat covering the transparent sensing layer, the transparent insulators, the metal connecting structures and the metal guiding lines. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a cross-sectional view of a conventional touch panel. 
         FIG. 2A  illustrates a top view of a thin touch panel formed with a black bordering according to an embodiment of the present invention. 
         FIG. 2B  illustrates a top view of a thin touch panel formed with a black bordering, metal connecting structures and metal guiding lines according to an embodiment of the present invention. 
         FIG. 2C  illustrates a top view of a thin touch panel formed with a black bordering, metal connecting structures, metal guiding lines and transparent insulators according to an embodiment of the present invention. 
         FIG. 2D  illustrates a top view of a thin touch panel formed with a black bordering, metal connecting structures, metal guiding lines, transparent insulators and a transparent sensing layer according to an embodiment of the present invention. 
         FIG. 2E  illustrates a top view of a thin touch panel formed with a black bordering, metal connecting structures, metal guiding lines, transparent insulators, a transparent sensing layer and a transparent over coat according to an embodiment of the present invention. 
         FIG. 2F  illustrates a cross-sectional view of the  FIG. 2E  along the line F-F′. 
         FIG. 2G  illustrates an applied example of a thin touch panel. 
         FIG. 3A  illustrates a top view of a thin touch panel formed with a black bordering according to another embodiment of the present invention. 
         FIG. 3B  illustrates a top view of a thin touch panel formed with a black bordering and a transparent sensing layer according to another embodiment of the present invention. 
         FIG. 3C  illustrates a top view of a thin touch panel formed with a black bordering, a transparent sensing layer and transparent insulators according to another embodiment of the present invention. 
         FIG. 3D  illustrates a top view of a thin touch panel formed with a black bordering, a transparent sensing layer, transparent insulators, metal connecting structures and metal guiding lines according to another embodiment of the present invention. 
         FIG. 3E  illustrates a top view of a thin touch panel formed with a black bordering, a transparent sensing layer, transparent insulators, metal connecting structures, metal guiding lines and a transparent over coat according to another embodiment of the present invention. 
         FIG. 3F  illustrates a cross-sectional view of the  FIG. 3E  along the line F-F′. 
         FIG. 3G  illustrates an applied example of a thin touch panel. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to specific embodiments of the present invention. Examples of these embodiments are illustrated in the accompanying drawings. While the invention will be described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the invention to these embodiments. In fact, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. In the following description, numerous specific details are set forth in order to provide a through understanding of the present invention. The present invention may be practiced without some or all of these specific details. In other instances, well-known process operations are not described in detail in order not to obscure the present invention. 
     Referring to  FIG. 2A , a thin touch panel comprises a transparent substrate  32  having an outer surface (not shown) and an inner surface  321  opposite to one another. The outer surface is capable of being a touch end. The inner surface  321  is designed with a sensing region  34 , and a black bordering  36  are formed on edges of the inner surface  321  to dispose around the sensing region  34 . In an embodiment, the transparent substrate  32  may be a transparent insulating board or a transparent insulating flexible board with a material of glass, polycarbonate (PC), polythylene terephthalate (PET), polymethylmethacrylate (PMMA), cyclic olefin copolymer (COC) or polyether sulfone (PES). However, the material of the transparent substrate  32  of the present invention is not limited to the previous materials. In addition, the black bordering  36  may be a black array pattern made of chromium (Cr), chromium oxide or resin. 
     In addition, referring to  FIG. 2B , a plurality of metal connecting structures  38  are arranged as an array and formed on the sensing region  34  of the inner surface  321 , and a plurality of metal guiding lines  40  are formed on a surface of the black bordering  36 . In an embodiment, the metal connecting structures  38  and the metal guiding lines  40  are formed on the sensing region  34  and on the black bordering  36  respectively by forming one or a stack of metal material layer(s) with a conventional method, such as, but not limited to, sputtering deposition method, wherein the metal material comprises at least one of, but not limited to, silver (Ag), chromium (Cr), aluminum (Al) or a molybdenum/aluminum/molybdenum (Mo/Al/Mo) stack layer. 
     Then referring to  FIG. 2C , a plurality of transparent insulators  42  are respectively corresponding to each metal connecting structures  38 , and respectively crosses and covers a center part of each metal connecting structures  38 , thus only two opposite ends of each metal connecting structures  38  are exposed. In an embodiment, the transparent insulators  42  are formed from a photosensitive transparent insulating layer made of, such as, but not limited to, ink or PET with high transparency after exposure and development processes. 
     Further, referring to  FIG. 2D , a transparent sensing layer  44  is disposed on the inner surface  321 . The transparent sensing layer  44  comprises a plurality of first sensing pads  441 , a plurality of transparent conductive connecting structures  442 , a plurality of second sensing pads  443  and a plurality of transparent guiding lines  444 . The first sensing pads  441  and the second sensing pads  443  are arranged alternately, and the second sensing pads  443  are disposed adjacent to and isolated from one another on the inner surface  321  of the sensing region  34 . The transparent conductive connecting structures  442  are respectively disposed across and covering surfaces of each transparent insulator  42  to electrically connect the first sensing pads  441  along a first direction X, and every two adjacent and isolated second sensing pads  443  are electrically connected by the exposed opposite ends of each metal connecting structures  38  respectively along a second direction Y (the second direction Y is different to the first direction X). In addition, a plurality of transparent guiding lines  444  cover corresponding surfaces of the metal guiding lines  40  (as illustrated in  FIG. 2B ). One end of each transparent guiding line  444  is electrically connected with a first sensing pad  441  or a second sensing pad  443  adjacent to the edges of the sensing region  34 , and the other end of each transparent guiding line  444  is electrically connected with a signal output flat cable or a conductive circuit (not shown). 
     In an embodiment, the first sensing pads  441  and the second sensing pads  443  are formed as rhombus shapes or polygon shapes, and sizes thereof are all the same or similar to one another. In addition, the transparent conductive connecting structures  442  are formed as strip shapes, thereby electrically connecting and tightly arranging the first sensing pads  441 . The transparent sensing layer  44  is formed from a transparent photosensitive conductive material, such as indium tin oxide (ITO), indium zinc oxide (IZO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), zinc oxide (ZnO), tin oxide (SnO 2 ) or organic transparent conductive material. In addition, the first sensing pads  441 , the transparent conductive connecting structures  442 , the second sensing pads  443  and the transparent guiding lines  444  are formed by processing a photolithography process on the same transparent photosensitive conductive material. 
     Then referring to  FIGS. 2E and 2F , wherein the  FIG. 2F  illustrates a cross-sectional view of the  FIG. 2E  along the line F-F′. A thin touch panel  30  may further comprise a transparent over coat  46  covering the transparent sensing layer  44 , the transparent insulators  42 , the metal connecting structures  38  and the metal guiding lines  40  mentioned above and only conductive pads  48  for electrically connecting outside are exposed, so as to protect the above-mentioned structure from being scraped except conductive pads  48 . In an embodiment, the transparent over coat  46  is formed from an insulating material, such as, but not limited to, silicon oxide (SiO 2 ). 
     Still referring to  FIG. 2F , wherein a black bordering  36 , metal connecting structures  38 , metal guiding lines  40 , transparent insulators  42  and a transparent sensing layer  44  are formed on the inner surface  321  of the transparent substrate  32 . The metal guiding lines  40  and transparent guiding lines  444  of the transparent sensing layer  44  are formed on the black bordering  36 , thereby being covered by the black bordering  36  and not exposed outside the transparent substrate  32 , so as to have artistic, orderly and integral effects. As an applied example illustrated in  FIG. 2G , a thin touch panel  30  of the present invention may be disposed on a display panel  50  to form a thin touch display screen  60 . 
     The present invention may further be formed by using another process. Referring to  FIG. 3A , a thin touch panel comprises a transparent substrate  32  having an outer surface (not shown) and an inner surface  321  opposite to one another. The outer surface is capable of being a touch end. The inner surface  321  is designed with a sensing region  34 , and a black bordering  36  are formed on edges of the inner surface  321  to dispose around the sensing region  34 . In an embodiment, the transparent substrate  32  may be a transparent insulating board or a transparent insulating flexible board, and the black bordering  36  may be a black array pattern. The materials have been illustrated in the previous embodiment and are omitted herein. 
     Further, referring to  FIG. 3B , a transparent sensing layer  44  is disposed on an inner surface  321  of the transparent substrate  32 . The transparent sensing layer  44  comprises a plurality of first sensing pads  441 , a plurality of transparent conductive connecting structures  442 , a plurality of second sensing pads  443  and a plurality of transparent guiding lines  444 . The transparent conductive connecting structures  442  herein electrically connect the first sensing pads  441  along a first direction X, and the second sensing pads  443  are adjacent to and isolated from one another and alternately arranged with the first sensing pads  441 . In addition, the transparent guiding lines  444  are formed on the black bordering  36  over the inner surface  321 , and part of the transparent guiding lines  444  are electrically connected to the first sensing pads  441  adjacent to the edges of the sensing region  34 , and another part of the transparent guiding lines  444  are electrically connected to the second sensing pads  443  adjacent to the edges of the sensing region  34 . The other end of each transparent guiding line  444  is electrically connected with a signal output flat cable or a conductive circuit (not shown). Similarly, the shapes, the materials and the processes of the first sensing pads  441 , the second sensing pads  443 , the transparent conductive connecting structures  442  and the transparent guiding lines  444  have been illustrated in the previous embodiment and are omitted herein. 
     Then referring to  FIG. 3C , a plurality of transparent insulators  42  are respectively corresponding to and covers on each transparent conductive connecting structures  442 , and respectively crossing on two adjacent ends of two isolated second sensing pads  443 . The material and the process of the transparent insulators  42  have been illustrated in the previous embodiment and are omitted herein. 
     In addition, referring to  FIG. 3D , a plurality of metal connecting structures  38  are arranged as an array and respectively formed on a surface of each transparent insulators  42  to electrically connect every two adjacent and isolated second sensing pads  443  along a second direction Y (the second direction is different to the first direction), and a plurality of metal guiding lines  40  are formed on the transparent guiding lines  444 . The metal materials and the processes thereof have been illustrated in the previous embodiment and are omitted herein. 
     Then referring to  FIGS. 3E and 3F , wherein the  FIG. 3F  illustrates a cross-sectional view of the  FIG. 3E  along the line F-F′. A thin touch panel  30  may further comprise a transparent over coat  46  covering the transparent sensing layer  44 , the transparent insulators  42 , the metal connecting structures  38  and the metal guiding lines  40  mentioned above and only conductive pads  48  for electrically connecting outside are exposed, so as to protect the above-mentioned structure from being scraped except conductive pads  48 .  FIG. 3G  illustrates an applied example of the present invention. Referring to  FIG. 3G , a thin touch panel  30  may be disposed on a display panel  50  to form a thin touch display screen  60 . 
     In summary, the black bordering, the sensing layer, the metal connecting structures, the transparent insulators and the guiding lines of the present invention are directly formed on the inner surface of the transparent substrate, thereby comprising the following benefits;
         1. the transparent substrate not only capable of being a touch end, but also having a touch control ability of thin touch panel directly;   2. comparing to the conventional touch panel, the glass substrate of the touch panel disposed between the cover lens and the display panel in the present invention capable of being simplified, so as to reduce material consumption and increase a transparency of the touch panel;   3. in the steps of manufacturing the structure of the present invention, the process of sticking the cover lens and the glass substrate by using the optical adhesive capable of being left out, so as to further reduce the cost of the sticking process and enhance the yield rate; and   4. the thickness of the whole structure of the touch panel capable of being reduced, so as to benefit a design tendency of thinning out the product.       

     Although specific embodiments of the present invention have been described, it will be understood by those of skill in the art that there are other embodiments that are equivalent to the described embodiments. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrated embodiments, but only by the scope of the appended claims.