Patent Publication Number: US-2015060125-A1

Title: Touch panel

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a touch panel, and more particularly, to a touch panel including an axis electrode formed monolithically. 
     2. Description of the Prior Art 
     In recent years, touch sensing technologies have developed flourishingly. There are many diverse technologies of touch panel, such as the resistance touch technology, the capacitive touch technology and the optical touch technology which are the main touch technologies in use. The capacitive touch technology has become the mainstream touch technology for the high-end and the mid-end consumer electronics, because the capacitive touch panel has advantages such as high precision, multi-touch property, better endurance, and higher touch resolution. As shown in  FIG. 1  and  FIG. 2 , in the conventional capacitive touch panel  100 , a first axis electrode  140 X and a second axis electrode  140 Y, which are used to perform touch sensing functions, are disposed on a substrate  110  and extend toward different directions respectively. In the first axis electrode  140 X, two adjacent sub-electrodes  140 S are electrically connected to each other via a connection line  120 . The connection line  120  is formed on the substrate first, and an insulation block  130  is then formed on the connection line  120  and partially exposes the connection line  120 . Afterward the second axis electrode  140 Y and the sub-electrodes  140 S are formed simultaneously, and the sub-electrodes  140 S can contact the connection line  120  exposed by the insulation block  130  for being electrically connected to each other. However, a contact interface between the sub-electrodes  140 S and the connection line  120  is formed no matter whether the materials of the sub-electrodes  140  and the connection line  120  are different or identical. The resistance at the contact interface will influence the electrostatic discharge protection ability. In other words, electrostatic discharge tends to occur at the contact interface between the sub-electrodes  140 S and the connection line  120 , and the reliability of the capacitive touch panel  100  may be affected. In addition, because the connection line  120  has to be partially exposed by the insulation block  130 , the connection line  120  may be damaged by the related manufacturing process of the insulation block  130 . For example, the developer used in the photolithography process of the insulation block  130  may damage the connection line  120 , the manufacturing yield may be affected, and the variability of materials and processes may be limited accordingly. 
     SUMMARY OF THE INVENTION 
     It is one of the objectives of the present invention to provide a touch panel. A monolithically formed first axis electrode and a monolithically formed second axis electrode are disposed and cross each other so as to enhance the electrostatic discharge protection ability in each axis electrode. Additionally, a first insulation layer is used to completely cover the first axis electrode. First sub-electrodes of the first axis electrode and second sub-electrodes of the second axis electrode may be disposed on the same surface by modifying the distribution condition of the first insulation layer. 
     To achieve the purposes described above, a preferred embodiment of the present invention provides a touch panel. The touch panel includes a substrate, a plurality of first axis electrodes, a plurality of second axis electrodes and a first insulation layer. The first axis electrodes are disposed on the substrate. Each of the first axis electrodes extends along a first direction, and each of the first axis electrodes includes a plurality of first sub-electrodes and a plurality of first connection parts. Each of the first connection parts is disposed between two adjacent first sub-electrodes so as to electrically connect the first sub-electrodes. Each of the first connection parts and two adjacent first sub-electrodes are monolithically formed. The second axis electrodes are disposed on the substrate. Each of the second axis electrodes extends along a second direction, the second direction crosses the first direction, and each of the second axis electrodes includes a plurality of second sub-electrodes and a plurality of second connection parts. Each of the second connection parts is disposed between two adjacent second sub-electrodes so as to electrically connect the second sub-electrodes. Each of the second connection parts and two adjacent second sub-electrodes are monolithically formed. The first sub-electrodes and the second sub-electrodes are disposed on an identical surface. The first insulation layer is disposed on the first axis electrodes and completely covers the first axis electrodes along a vertical projective direction perpendicular to the substrate. The first insulation layer is partially disposed between each first connection part and each second connection part so as to electrically insulate the first axis electrodes from the second axis electrodes, and the first axis electrodes are disposed between the first insulation layer and the substrate. 
     In the touch panel of the present invention, the first axis electrode and the second axis electrode extend along different direction. Each of the first axis electrodes is monolithically formed, and each of the second axis electrodes is monolithically formed so as to enhance the electrostatic discharge protection ability. In addition, the first insulation layer completely covering the first axis electrodes is used to keep the first axis electrodes from being damaged by the manufacturing processes of the first insulation layer. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating a conventional capacitive touch panel. 
         FIG. 2  is a schematic cross-sectional diagram taken along a line A-A′ in  FIG. 1 . 
         FIG. 3  is a schematic diagram illustrating a touch panel according to a first embodiment of the present invention. 
         FIG. 4  is a schematic cross-sectional diagram taken along a line B-B′ in  FIG. 3 . 
         FIG. 5  is a schematic diagram illustrating a touch panel according to a second embodiment of the present invention. 
         FIG. 6  is a schematic cross-sectional diagram taken along a line C-C′ in  FIG. 5 . 
         FIG. 7  is a schematic diagram illustrating a touch panel according to a third embodiment of the present invention. 
         FIG. 8  is a schematic cross-sectional diagram taken along a line D-D′ in  FIG. 7 . 
         FIG. 9  is a schematic diagram illustrating a touch panel according to a fourth embodiment of the present invention. 
         FIG. 10  is a schematic cross-sectional diagram taken along a line E-E′ in  FIG. 9 . 
         FIG. 11  is a schematic diagram illustrating a touch panel according to a fifth embodiment of the present invention. 
         FIG. 12  is a schematic diagram illustrating a touch panel according to a sixth embodiment of the present invention. 
         FIG. 13  is a schematic diagram illustrating a touch panel according to a seventh embodiment of the present invention. 
         FIG. 14  is a schematic cross-sectional diagram taken along a line F-F′ in  FIG. 13 . 
         FIG. 15  is a schematic diagram illustrating a touch panel according to an eighth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     To provide a better understanding of the present invention to the skilled users in the technology of the present invention, preferred embodiments will be detailed as follows. The preferred embodiments of the present invention are illustrated in the accompanying drawings with numbered elements to elaborate the contents and effects to be achieved. 
     Please refer to  FIG. 3  and  FIG. 4 .  FIG. 3  is a schematic diagram illustrating a touch panel according to a first embodiment of the present invention.  FIG. 4  is a schematic cross-sectional diagram taken along a line B-B′ in  FIG. 3 . Please note that the figures are only for illustration and the figures may not be to scale. The scale may be further modified according to different design considerations. As shown in  FIG. 3  and  FIG. 4 , a touch panel  200  is provided in this embodiment. The touch panel  200  includes a substrate  210 , a plurality of first axis electrodes  220 X, a plurality of second axis electrodes  240 Y and a first insulation layer  230 . The first axis electrodes  220 X are disposed on the substrate  210 . Each of the first axis electrodes  220 X extends along a first direction X. Each of the first axis electrodes  220 X includes a plurality of first sub-electrodes  220 S and a plurality of first connection parts  220 C. Each of the first connection parts  220 C is disposed between two adjacent first sub-electrodes  220 S so as to electrically connect the first sub-electrodes  220 S. Each of the first connection parts  220 C and two adjacent first sub-electrodes  220 S are monolithically formed. In other words, the first connection parts  220 C and the first sub-electrodes  220 S within one identical first axis electrode  220 X are monolithically formed. For example, the first axis electrodes  220 X may be formed by patterning a first conductive layer  220 , and the first connection parts  220 C and the first sub-electrodes  220 S are formed simultaneously and monolithically without any interfaces between the first connection part  220 C and the first sub-electrode  220 S. Additionally, the second axis electrodes  240 Y are disposed on the substrate  210 . Each of the second axis electrodes  240 Y extends along a second direction Y, and the second direction Y crosses the first direction X. The first direction X is substantially perpendicular to the second direction Y preferably, but not limited thereto. Each of the second axis electrodes  240 Y includes a plurality of second sub-electrodes  240 S and a plurality of second connection parts  240 C. Each of the second connection parts  240 C is disposed between two adjacent second sub-electrodes  240 S so as to electrically connect the second sub-electrodes  240 S. Each of the second connection parts  240 C and two adjacent second sub-electrodes  240 S are monolithically formed. In other words, the second connection parts  240 C and the second sub-electrodes  240 S within one identical second axis electrode  240 Y are monolithically formed. For example, the second axis electrodes  240 Y may be formed by patterning a second conductive layer  240 , and the second connection parts  240 C and the second sub-electrodes  240 S are formed simultaneously and monolithically without any interfaces between the second connection part  240 C and the second sub-electrode  240 S. In addition, a width of each first sub-electrode  220 S along the second direction Y is wider than a width of each first connection part  220 C along the second direction Y, and a width of each second sub-electrode  240 S along the first direction X is wider than a width of each second connection part  240 C along the first direction X. By the design described above, the resistance issue at the interface between the sub-electrodes and the connection parts may be avoided, the electrostatic discharge protection ability of each axis electrode may be enhanced, and the reliability of the touch panel  200  may be improved accordingly. 
     In this embodiment, the first sub-electrodes  220 S and the second sub-electrodes  240 S are disposed on one identical surface. Specifically, the first sub-electrodes  220 S and the second sub-electrodes  240 S are disposed on a first surface  210 A of the substrate  210 , and a second surface  210 B opposite to the first surface  210 A may be a touch operation surface, but not limited thereto. It is worth noting that other film layers, such as inorganic buffer layers (silicon oxide for example), may be disposed between the substrate  210  and the first sub-electrodes  220 S and/or disposed between the substrate  210  and the second sub-electrodes  240 S. In addition, the first insulation layer  230  is disposed on the first axis electrodes  220 X and completely covers the first axis electrodes  220 X along a vertical projective direction Z perpendicular to the substrate  210 . In other words, the first insulation layer  230  covers edges of each first axis electrode  220 X. The first insulation layer  230  is partially disposed between each first connection part  220 C and each second connection part  240 C so as to electrically insulate the first axis electrodes  220 X from the second axis electrodes  240 Y. The first axis electrodes  220 X are disposed between the first insulation layer  230  and the substrate  210 . In other words, in a manufacturing method of the touch panel  200  in this embodiment, the first conductive layer  220  may be formed on the substrate  210  first, and the first axis electrodes  220 X may then be formed by patterning the first conductive layer  220 . Subsequently, the first insulation layer  230  is formed to completely cover the first axis electrodes  220 X, the second conductive layer  240  is then formed on the first insulation layer  230  and the substrate  210 , and the second axis electrodes  240 Y are then formed by patterning the second conductive layer  240 . In this embodiment, the first conductive layer  220  and the second conductive layer  240  may include a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO) and nano metal wire, or other appropriate opaque conductive materials such as metal material. The metal material mentioned above may include silver (Ag), aluminum (Al), copper (Cu), magnesium (Mg), molybdenum (Mo), a composite layer of the above-mentioned materials, or an alloy of the above-mentioned materials, but not limited thereto. Additionally, the structures of the first conductive layer  220  and the second conductive layer  240  may be a thin film or a mesh. For example, the first conductive layer  220  and the second conductive layer  240  may be ITO thin films or metal mesh. The metal mesh may be consisted of a plurality of fine metal lines, and a line width of the fine metal line may range between 1 micrometer and 30 micrometers. In the metal mesh electrodes, an aperture between the fine metal lines is much larger than the width of the fine metal line, and the light transmittance of the metal mesh electrode may be higher than 75%. In addition, the substrate  210  may include a rigid substrate or a flexible substrate. For example, the substrate  210  may include a glass substrate, a sapphire, a rigid cover lens, a plastic substrate, a flexible cover lens, a flexible plastic substrate, a thin glass substrate or a substrate of a display device. The substrate of the display device may be a color filter substrate of a liquid crystal display device or an encapsulation plate of an organic light emitting display device, but not limited thereto. In other words, the first axis electrodes  220 X and the second axis electrodes  240 Y in this embodiment may include transparent materials or metal mesh preferably so as to integrate the touch panel  200  with a display device or combine the touch panel  200  and a display device, but not limited thereto. 
     It is worth noting that, in this embodiment, an outline of the first insulation layer  230  is the same as an outline of the first axis electrodes  220 X preferably, and a shape of the first insulation layer  230  is the same as a shape of the first axis electrodes  220 X preferably. The first insulation layer  230  encompasses the first axis electrodes  220 X so as to keep the first axis electrodes  220 X from being damaged by the manufacturing processes of the first insulation layer  230 . For example, the developer used in the photolithography process of the first insulation layer  230  may damage the first axis electrodes  220 X if the first axis electrodes are not covered by the first insulation layer  230 . However, in other embodiments of the present invention, the first insulation layer  230  in other shapes may also be used to encompass the first axis electrodes  220 X. The first insulation layer  230  may include single layer or multiple layer structures formed by inorganic materials, such as silicon nitride, silicon oxide and silicon oxynitride, organic materials, such as acrylic resin, or other appropriate materials. In this embodiment, a refractive index of the first axis electrodes  220 X is higher than a refractive index of the first insulation layer  230  and a refractive index of the substrate  210  preferably so as to generate refractive index matching effect for lowering the pattern visibility of the first axis electrodes  220 X, but not limited thereto. 
     The following description will detail the different embodiments of the present invention. To simplify the description, identical components in each of the following embodiments are marked with identical symbols. For making it easier to understand the differences between the embodiments, the following description will detail the dissimilarities among different embodiments and the identical features will not be redundantly described. 
     Please refer to  FIG. 5  and  FIG. 6 .  FIG. 5  is a schematic diagram illustrating a touch panel  300  according to a second embodiment of the present invention.  FIG. 6  is a schematic cross-sectional diagram taken along a line C-C′ in  FIG. 5 . As shown in  FIG. 5  and  FIG. 6 , the difference between the touch panel  300  in this embodiment and the touch panel in the first embodiment is that, in the touch panel  300 , the first insulation layer  230  has a plurality of openings  230 H, and each of the second sub-electrodes  240 S is disposed in one of the openings  230 H correspondingly. In other words, the first insulation layer  230  completely covers the first axis electrodes  220 X along the vertical projective direction Z and has a plurality of openings  230 H disposed at regions without first axis electrodes  220 X on the substrate  210  so as to partially expose the substrate  210 . Each of the second sub-electrodes  240 S is disposed in one of the openings  230 H correspondingly, and the first sub-electrodes  220 S and the second sub-electrodes  240 S may then be disposed on the identical surface. 
     Please refer to  FIG. 7  and  FIG. 8 .  FIG. 7  is a schematic diagram illustrating a touch panel  400  according to a third embodiment of the present invention.  FIG. 8  is a schematic cross-sectional diagram taken along a line D-D′ in  FIG. 7 . As shown in  FIG. 7  and  FIG. 8 , the difference between the touch panel  400  in this embodiment and the touch panel in the first embodiment is that the touch panel  400  further includes a second insulation layer  250  disposed on the second axis electrodes  240 Y. The second insulation layer  250  completely covers the second axis electrodes  240 Y along the vertical projective direction Z, and the second axis electrodes  240 Y are disposed between the second insulation layer  250  and the substrate  210 . In other words, the second insulation layer  250  covers edges of each second axis electrode  240 Y. In this embodiment, an outline of the second insulation layer  250  is the same as an outline of the second axis electrodes  240 Y preferably, and a shape of the second insulation layer  250  is the same as a shape of the second axis electrodes  240 Y preferably. The second insulation layer  250  encompasses the second axis electrodes  240 Y. However, in other embodiments of the present invention, the second insulation layer  250  in other shapes may also be used to encompass the second axis electrodes  240 Y. The second insulation layer  250  may include single layer or multiple layer structures formed by inorganic materials, such as silicon nitride, silicon oxide and silicon oxynitride, organic materials, such as acrylic resin, or other appropriate materials. In this embodiment, a refractive index of the second axis electrodes  240 Y is higher than a refractive index of the second insulation layer  250  and the refractive index of the substrate  210  preferably so as to generate refractive index matching effect for lowering the pattern visibility of the second axis electrodes  240 Y, but not limited thereto. Additionally, in other embodiments of the present invention, the first insulation layer  230  may at least partially overlap the second insulation layer  250  along the vertical projective direction Z so as to further lower the pattern visibility, but not limited thereto. 
     Please refer to  FIG. 9  and  FIG. 10 .  FIG. 9  is a schematic diagram illustrating a touch panel  500  according to a fourth embodiment of the present invention.  FIG. 10  is a schematic cross-sectional diagram taken along a line E-E′ in  FIG. 9 . As shown in  FIG. 9  and  FIG. 10 , the difference between the touch panel  500  in this embodiment and the touch panel in the third embodiment is that, in the touch panel  500 , the second insulation layer  250  is one film layer with a full or complete surface covering the first axis electrodes  220 X and the second axis electrodes  240 Y so as to lower the pattern visibility of each first axis electrode  220 X and each second axis electrode  240 Y. 
     Please refer to  FIG. 11 .  FIG. 11  is a schematic diagram illustrating a touch panel  600  according to a fifth embodiment of the present invention. As shown in  FIG. 11 , the difference between the touch panel  600  in this embodiment and the touch panel in the first embodiment is that the touch panel  600  further includes a protection layer  660  or an adhesion layer  670  covering the first axis electrodes  220 X, the second axis electrodes  240 Y and the first insulation layer  230 . The protection layer  660  may include inorganic materials, such as silicon nitride, silicon oxide and silicon oxynitride, organic materials, such as acrylic resin, or other appropriate materials. The protection layer  660  is used to protect the first axis electrodes  220 X and the second axis electrodes  240 Y. A refractive index of the protection layer  660  is lower than the refractive index of the first insulation layer  230  preferably, and the refractive index of the first axis electrodes  220 X is higher than the refractive index of the first insulation layer  230  preferably so as to generate refractive index matching effect for lowering the pattern visibility, but not limited thereto. For example, the refractive index of the protection layer  660  may also be higher than the refractive index of the first insulation layer  230 . In addition, the adhesion layer  670  is used to adhere to another device such as a display panel, but not limited thereto. The adhesion layer  670  may include optical clear adhesive (OCA), pressure sensitive adhesive (PSA) or other appropriate adhesion materials preferably. A refractive index of the adhesion layer  670  is lower than the refractive index of the first insulation layer  230 , and the refractive index of the first axis electrodes  220 X is higher than the refractive index of the first insulation layer  230  preferably so as to generate refractive index matching effect for lowering the pattern visibility, but not limited thereto. It is worth noting that the protection layer  660  and/or the adhesion layer  670  in this embodiment may also be selectively applied to other embodiments of the present invention so as to the pattern visibility by adjust the index refraction matching conditions. 
     Please refer to  FIG. 12 .  FIG. 12  is a schematic diagram illustrating a touch panel  700  according to a sixth embodiment of the present invention. As shown in  FIG. 12 , the difference between the touch panel  700  in this embodiment and the touch panel in the first embodiment is that, in the touch panel  700 , the first axis electrodes  220 X and the second axis electrodes  240 Y are made of metal mesh. The metal mesh may include continuously stacked geometric figures in similar size or different shapes. The geometric figures of the metal mesh may include rhombus patterns, square patterns, rectangle patterns, hexagon patterns, other regular patterns or irregular patterns. Additionally, the metal mesh may also include a sine wave mesh pattern or other appropriate mesh patterns. It is worth noting that, in other embodiments mentioned above or below, the first axis electrodes  220 X and the second axis electrodes  240 Y may also be consisted of metal mesh. The first connection parts  220 C and the first sub-electrodes  220 S may then be formed monolithically without interface between the first connection parts  220 C and the first sub-electrodes  220 S, and the second connection parts  240 C and the second sub-electrodes  240 S may then be formed monolithically without interface between the second connection parts  240 C and the second sub-electrodes  240 S. The electrostatic discharge protection ability may be enhanced accordingly. 
     Please refer to  FIG. 13  and  FIG. 14 .  FIG. 13  is a schematic diagram illustrating a touch panel  800  according to a seventh embodiment of the present invention.  FIG. 14  is a schematic cross-sectional diagram taken along a line F-F′ in  FIG. 13 . As shown in  FIG. 13  and  FIG. 14 , the difference between the touch panel  800  in this embodiment and the touch panel in the first embodiment is that the touch panel  800  further includes a plurality of dummy patterns  880  disposed between each of the first sub-electrodes  220 S and adjacent second sub-electrodes  240 S. The dummy patterns  880  are electrically isolated from the first axis electrodes  220 X and the second axis electrodes  240 Y. The spacing between the first axis electrodes  220 X and the second axis electrodes  240 Y may be filled with the dummy patterns  880  so as to lower the pattern visibility of the first axis electrodes  220 X and the second axis electrodes  240 Y. Each of the dummy patterns  880  may include a conductive pattern  881  and an insulation pattern  882 . The conductive pattern  881  is disposed between the insulation pattern  882  and the substrate  210 . Specifically, the conductive pattern  881  and the first axis electrodes  220 X may be formed by patterning one identical conductive layer, and the insulation pattern  882  and the first insulation layer  230  may be formed by one identical material, but not limited thereto. In other embodiments of the present invention, the conductive pattern  881  may also be formed by the manufacturing processes of the second axis electrodes  240 Y, and the insulation pattern  882  may also be formed by the manufacturing processes of the second insulation layer (not shown in  FIG. 13  and  FIG. 14 ). Additionally, the shape and the amount of the dummy patterns  880  may be further modified according to other design considerations, and the dummy patterns  880  may also be applied in other embodiments mentioned above in the present invention so as to lower the pattern visibility of the first axis electrodes  220 X and the second axis electrodes  240 Y. 
     Please refer to  FIG. 15 .  FIG. 15  is a schematic diagram illustrating a touch panel  601  according to an eighth embodiment of the present invention. As shown in  FIG. 15 , the difference between the touch panel  601  in this embodiment and the touch panel in the fifth embodiment is that the touch panel  601  includes both the protection layer  660  and the adhesion layer  670 . The protection layer  660  and the adhesion layer  670  cover the first axis electrodes  220 X, the second axis electrodes  240 Y and the first insulation layer  230 . The adhesion layer  670  is disposed on the protection layer  660  and covers the protection layer  660  preferably. The refractive index of the protection layer  660  is lower than the refractive index of the first insulation layer  230  preferably, and the refractive index of the first axis electrodes  220 X is higher than the refractive index of the first insulation layer  230  preferably. 
     To summarize the above descriptions, in the touch panel of the present invention, each first axis electrode and each second axis electrode extend along different directions. Each of the first axis electrodes is monolithically formed, and each of the second axis electrodes are monolithically formed so as to enhance the electrostatic discharge protection ability of the first axis electrodes and the second axis electrodes. Additionally, the first insulation layer is used to completely cover the first axis electrodes and keep the first axis electrodes from being damaged by the manufacturing processes of the first insulation layer. The first sub-electrodes of the first axis electrodes and the second sub-electrodes of the second axis electrodes are disposed on one identical surface. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.