Patent Publication Number: US-2015085205-A1

Title: Touch panel

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 102134087, filed on Sep. 23, 2013. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a touch panel, and more particularly, to a projected capacitive touch panel. 
     2. Description of Related Art 
     In a conventional capacitive touch panel, one of a 2D touch sensor is composed of a plurality of first conductive elements and a plurality of second conductive elements disposed on a substrate, in which the first and second conductive elements are respectively extended along different directions, insulated and intersected with each other. Generally, a common operating method for touch control is to perform input by using an electrical conductor such as a finger or a capacitive stylus. In consideration of requirements for a more accurate input, a contact area of the stylus is usually designed to be smaller. Accordingly, when it comes to improve touch resolution and sensing linearity, the first conductive elements and the second conductive elements are usually designed into more complex patterns. 
     In order to meet requirements for improving touch sensitivity, a pattern of the regions where the first conductive elements and the second conductive elements are not overlapped is usually densely distributed. Meanwhile, in order to prevent sensing sensitivity from being influenced by a parasitic capacitance generated at the regions where the first conductive elements and the second conductive elements are overlapped, the intersections of the first conductive elements and the second conductive elements are usually designed into an narrow elongated pattern. However, such design of the narrow elongated pattern is prone to a current crowding effect thereby causing signal attenuation or triggering an electrostatic discharge effect. Further, in consideration of thinning the touch panel, a small area of insulation structures may be disposed to separate the intersections of the first conductive elements and the second conductive elements, so that the first conductive elements and the second conductive elements are electrically independent from each other. Generally, the insulation structure is a relatively protruded structure, namely, the insulation structure may cause an uneven surface, thereby increasing difficulties in subsequent steps for layer disposition and film patterning. More specifically, under said structure, during manufacturing processes of the first conductive elements and the second conductive elements, conductive material located above the insulation patterns are prone to cracks, or the conductive material at a climbing portion of the insulation structures may have thinner film thickness, thereby influencing a quality of the touch panel. Furthermore, the electrostatic discharge effect may cause breakages of the conductive material, such that local area of the capacitive touch panel may unable to provide touch-sensing function. 
     SUMMARY OF THE INVENTION 
     Accordingly, the invention is directed to a touch panel in which a capability of resisting a static discharge effect can be improved while ensuring a quality of a sensing sensitivity by controlling a linewidth of the conductive elements. 
     A touch panel of the invention includes a substrate, a plurality of first conductive elements and a plurality of second conductive elements. The first conductive elements are disposed on the substrate; each of the first conductive elements includes a plurality of first conductive patterns and a plurality of first connection portions; each of the first connection portions is disposed between adjacent two of the first conductive patterns; and each of the first conductive patterns is electrically connected to one of the first connection portions. The second conductive elements are electrically insulated from the first conductive element. Each of the second conductive elements includes a plurality of intersection portions respectively intersected with the first connection portions. A linewidth of the intersection portions is represented as W1, in which it satisfies a condition of 100 μm&lt;W1≦300 μm. A sum of areas of regions where the first conductive elements and the second conductive elements are not overlapped is greater than a sum of areas of regions where the first conductive elements and the second conductive elements are overlapped. 
     In an embodiment, the touch panel further includes a plurality of insulation patterns, and each of the insulation patterns is disposed between one of the first connection portions and a corresponding one of the intersection portions intersected with the one of the first connection portions. 
     In an embodiment, each of the second conductive elements includes a plurality of second conductive patterns and at least one second connection portion, each of the at least one second connection portion is disposed between adjacent two of the second conductive patterns, each of the second conductive patterns is electrically connected to one of the at least one second connection portion, and the intersection portions are located in the second conductive patterns. 
     In an embodiment, a linewidth of the second connection portion is W2, and satisfies a condition of 20 μm&lt;W2&lt;W1. 
     In an embodiment, an accommodating space is defined between adjacent two of the second conductive patterns and any one of two sides of the second connection portion, and each of the first conductive elements has at least one first conductive branch being extended into the accommodating space. 
     In an embodiment, the insulation pattern exposes two ends of the first connection portion, the first conductive patterns are disposed on the two ends of the first connection portion, a partial region of the insulation pattern and the substrate, the first conductive pattern being inwardly extended from an edge of the insulation pattern for a distance not less than 20 μm. 
     In an embodiment, a minimum linewidth of the first connection portion is not greater than the linewidth of the intersection portion. 
     In an embodiment, the first connection portions include a plurality of first connection patterns and a plurality of second connection patterns, and the first connection patterns and the second connection patterns are alternately disposed between adjacent two of the first conductive patterns, wherein two or more of the first connection patterns are disposed between adjacent two of part of the first conductive patterns, and each two of the first connection patterns encircle an opening. 
     In an embodiment, a width of the second connection pattern is greater than a width of the first connection pattern. 
     In an embodiment, a part of the second conductive element is surrounded by a normal projection of two of the first connection patterns being arc-shaped. 
     In an embodiment, the first connection pattern is surrounded by a normal projection of two of the intersection portions being arc-shaped. 
     In an embodiment, a maximum width of the second connection pattern is greater than a minimum width of the first conductive pattern. 
     In an embodiment, the second conductive element includes a hollow portion, the intersection portions are located at two ends of the hollow portion, the first connection portion includes a filling section and a plurality of first intersecting sections, the filling section is located in the hollow portion, the first intersecting sections are located at the two ends of the filling section, and each of the first intersecting sections is intersected with one of the intersection portions and electrically connects the filling section and one of the first conductive patterns together. 
     In an embodiment, each of the second conductive elements includes a conductive trunk, and the intersection portions are located in the conductive trunk, wherein a linewidth of any portion of the conductive trunk other than the intersection portions is substantially identical to a linewidth of any one of the intersection portions. 
     In an embodiment, each of the second conductive elements further includes a plurality of second conductive branches, and the second conductive branches are extruded from two opposite sides of the conductive trunk. 
     In an embodiment, a linewidth W3 of each of the second branches is substantially uniform, and is not greater than the linewidth W1. 
     In an embodiment, a plurality of floating dummy electrodes is further respectively located between the conductive trunk and the first conductive pattern, wherein each of the floating dummy electrodes has at least one terminal with acute angle. 
     In an embodiment, a plurality of floating dummy electrodes is further included, wherein two or more of the floating dummy electrodes are located an insulating spacing between one of the conductive trunks and the adjacent one of the first conductive patterns. 
     Based on a purpose of the invention, a touch panel having a light transmissive region is further provided. The touch panel includes a substrate made of light transmissive materials, a plurality of first conductive elements, a plurality of second conductive elements and a plurality insulation patterns. The first conductive elements are disposed on the substrate and at least located at the light transmissive region; each of the first conductive elements includes a plurality of first conductive patterns and a plurality of first connection portions; each of the first connection portions is disposed between adjacent two of the first conductive patterns; and each of the first conductive patterns and one of the first connection portions are electrically connected to each other. The second conductive elements are disposed on the substrate and at least located at the light transmissive region, and the first conductive elements and the second conductive elements are intersected with each other and electrically insulated. The second conductive element includes a plurality of intersection portions respectively intersected with the first connection portions of each of the first conductive elements. A linewidth of the intersection portion is greater than a linewidth of the first connection portion. Each of the insulation patterns is disposed between one of the first connection portions and a corresponding one of the intersection portions intersected with the one of the first connection portions. A sum of areas of regions where the first conductive elements and the second conductive elements are not overlapped is greater than a sum of areas of regions where the first conductive elements and the second conductive elements are overlapped. 
     In an embodiment, a linewidth of the intersection portion is W1, and satisfies a condition of 100 μm&lt;W1≦300 μm. 
     In an embodiment, each of the second conductive elements includes a conductive trunk, and the intersection portions are located in the conductive trunk. A linewidth of any portion of the conductive trunk other than the intersection portions is substantially identical to the linewidth of any one of the intersection portions. 
     In an embodiment, the touch panel further includes a decoration layer and a plurality of signal transmission lines, in which the decoration layer is disposed on the substrate and corresponding to a light shielding region adjoined to the light transmissive region. The signal transmission lines are concealed by the decoration layer. The first conductive elements and the second conductive elements are further located at the light shielding region to electrically connect to the signal transmission lines on the decoration layer. 
     Based on above, in the touch panel of the invention, the linewidths of the intersections of the first conductive elements and the second conductive elements are well controlled, and the sum of areas of regions where the first conductive elements and the second conductive elements are not overlapped is greater than a sum of areas of regions where the first conductive elements and the second conductive elements are overlapped, such that a preferable touch sensitivity can be provided. Further, in order to provide a thinner and lighter touch panel, the first conductive elements and the second conductive elements are insulated from each other in each of the overlapping regions by disposing discontinuous insulation patterns. Furthermore, the touch panel can be even thinner and lighter when the first conductive elements, the second conductive elements, the insulation patterns and the decoration layer are formed on a cover lens. In this case, since the second conductive element located on the insulation pattern has a sufficient width, the capability of resisting a static discharge effect is provided to avoid the cracks occurring on the second conductive elements and ensure that the touch panel may provide a favorable performance. Moreover, by making the second conductive elements to have a uniform linewidth, the current crowding effect may be reduced to provide a simpler arrangement leading to an easier production. 
     To make the above features and advantages of the disclosure more comprehensible, several embodiments accompanied with drawings are described in detail as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic top view of a touch panel according to an embodiment of the invention. 
         FIG. 1B  is a schematic cross-sectional view taken along line A-A′ depicted in  FIG. 1A . 
         FIG. 1C  is a schematic cross-sectional view taken along line B-B′ depicted in  FIG. 1A . 
         FIG. 2A  is a schematic top view of a touch panel according to another embodiment of the invention. 
         FIG. 2B  is a schematic cross-sectional view taken along line C-C′ depicted in  FIG. 2A . 
         FIG. 3A  is a schematic top view of a touch panel according to another embodiment of the invention. 
         FIG. 3B  is a schematic cross-sectional view taken along line D-D′ depicted in  FIG. 3A . 
         FIG. 4A  is a schematic top view of a touch panel according to another embodiment of the invention. 
         FIG. 4B  is an enlarged schematic view of an area M depicted in  FIG. 4A . 
         FIG. 4C  is a schematic cross-sectional view taken along line E-E′ depicted in  FIG. 4A . 
         FIG. 5A  is a schematic top view of a touch panel according to another embodiment of the invention. 
         FIG. 5B  is a schematic cross-sectional view taken along line F-F′ depicted in  FIG. 5A . 
         FIG. 5C  is an enlarged schematic view of a driving circuit depicted in  FIG. 5A . 
         FIG. 6  is a schematic top view of a touch panel according to another embodiment of the invention. 
         FIG. 7  is a schematic top view of a touch panel according to another embodiment of the invention. 
         FIG. 8  is a schematic top view of a touch panel according to another embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
       FIG. 1A  is a schematic top view of a touch panel according to an embodiment of the invention.  FIG. 1B  is a schematic cross-sectional view taken along line A-A′ depicted in  FIG. 1A .  FIG. 1C  is a schematic cross-sectional view taken along line B-B′ depicted in  FIG. 1A . Referring to  FIG. 1A ,  FIG. 1B  and  FIG. 1C , a touch panel  100  includes a substrate  102 , a plurality of first conductive elements  110 , a plurality of second conductive elements  120 , a plurality of insulation patterns  130 , a plurality of signal transmission lines  140  and a decoration layer  150 . The touch panel  100  may include a light transmissive region and a light shielding region for being positioned on or integrated with a display. The light transmissive region corresponds to display units such as a liquid crystal display or an organic light-emitting diode, and the light shielding region is configured to shade visible elements or light not intended to be seen, such element may be, for example, the signal transmission lines  140  made of visible conductive material. In order to maximize a display area of an electronic device, demands for narrower border are increased, the visible elements are usually positioned in a peripheral region of the substrate  102 . Moreover, the visible elements may be positioned corresponding to only one side margin of the substrate  102 . Based on the same reason, at least one side margin of the touch panel  100  may have the light shielding region, while the remaining part of the touch panel  100  may correspond to the light transmissive region. The decoration layer  150  is positioned within the light shielding region, so as to be disposed on at least one side margin of the substrate  102 . The decoration layer  150  is composed of a light shielding material, which is defined as a material deemed to render a light lost when the light passes through an interface thereof, up to and including complete opacity. Through the decoration layer  150 , the visible elements or light not intended to be seen in the device can be concealed. A material of the decoration layer  150  may be a ceramic, a diamond-like carbon, an ink or a light shielding photoresist, but the invention is not limited thereto. Furthermore, in other embodiments not illustrated, the light shielding region may also include a visible icon, such as texts, logos, decorative patterns or function keys. Or, a part of the decoration layer may be patterned to be a light transmissive pattern. 
     Each of the first conductive elements  110  is disposed on the substrate  102  and extends along a first direction D1. The first conductive element  110  includes a plurality of first conductive patterns  112  and a plurality of first connection portions  114 . Each of the first connection portions  114  is disposed between and electrically connected to adjacent two of the first conductive patterns  112 . The first conductive pattern  112  may be made of a transparent conductive material including indium tin oxide (ITO), indium-zinc oxide (IZO), gallium-zinc oxide (GZO), carbon nanotube-based thin films, metal nanowires, such as silver nanowires, graphene, silicene or other high conductive materials with invisible configuration, such as metal grids composed of metal wires with a linewidth less than 10 μm, but the invention is not limited thereto. 
     Each of the second conductive elements  120  is disposed on the substrate  102  and extends along a second direction D2 intersected with the first direction D1. The second conductive elements  120  are electrically insulated from the first conductive elements  110 . A sum of areas of regions where the first conductive elements  110  and the second conductive elements  120  are not overlapped is greater than a sum of areas of regions where the first conductive elements  110  and the second conductive elements  120  are overlapped. Accordingly, the conductive elements may be more densely distributed to improve a sensing sensitivity and a coordinate resolution of the touch panel. Therein, the second conductive element  120  includes a plurality of intersection portions  124  respectively intersected with the first connection portions  114  of each of the first conductive elements  110 . A minimum linewidth of the first intersection portion  114  may be not greater than a linewidth W1 of the intersection portion  124 . In the present embodiment, the second conductive element  120  includes a plurality of second conductive patterns  122  and a plurality of second connection portions  122   b . Each of the second connection portions  122   b  is disposed between and electrically connected to adjacent two of the second conductive patterns  122 . The second conductive pattern  122  may be composed of materials such as a transparent conductive material including indium tin oxide (ITO), indium-zinc oxide (IZO), gallium-zinc oxide (GZO), carbon nanotube-based thin films, metal nanowires, such as silver nanowires, graphene, silicene or other high conductive materials, with invisible configuration, such as metal grids composed of metal wires with a linewidth less than 10 μm, but the invention is not limited thereto. Therein, the second connection portion  122   b  may be of a thin metal wire or a material identical to that of the second conductive patterns  122 . 
     Each of the insulation patterns  130  is disposed between the first connection portion  114  and the intersection portion  124  of the second conductive element  120 , so that the first conductive element  110  and the second conductive element  120  are electrically insulated from each other. In the present embodiment, each of the insulation patterns  130  covers the first connection portion  114  of the first conductive element  110 . By using the first conductive element  110  and the second conductive element  120 , in case a conductive object (e.g., a finger) is approaching or contacting a surface of the touch panel, coupling capacitances are then generated between the object and the approaching conductive elements. As a result, a position or a movement of the object may be detected according to capacitance variation at a region where the object is approached to or contacted. Therein, the object may contact an outer surface of an insulator such as a cover lens, to perform a touch control. Or, a proximity hovering touch control without touching the touch panel may be performed. In addition, details related to a touch detection measurement method of the capacitive touch panel may refer to the well known measurement methods, such as a self capacitance measurement method or a mutual capacitance measurement method. However, the invention is not limited to any specific measurement methods. 
     The insulation patterns  130  are not overlapped with the second connection portions  122   b . More specifically, the first connection portion  114  is, for example, a strip conductive pattern disposed on the substrate  102 , and made of a conductive material including a metal material, a metallic oxide material, or a composite laminate including at least one metal layer and at least one metallic oxide layer, but the invention is not limited thereto. In case the touch panel  100  is disposed in front of a display, the first connection portion  114  may be made of the conductive material selected from the above-mentioned transparent conductive material or the thin metal wire that is hardly visible to naked-eye, in which a linewidth of the thin metal wire is usually less than 20 μm. The insulation pattern  130  covers a partial region of the first connection portion  114  and expose two ends of the first connection portion  114 . Herein, the first conductive patterns  112  disposed next to the first connection portion  114  respectively covers the two ends of the first connection portion  114  exposed by the insulation pattern  130 , so that the first conductive patterns  112  along the first direction D1 are electrically connected together by the first connection portion  114  in one first conductive element  110 . In the present embodiment, the first connection portion  114  and the first conductive pattern  122  are fabricated separately, and the first conductive pattern  112  is further extended to cover a partial region of the insulation pattern  130 . More specifically, the first conductive pattern  122  may be inwardly extended from an edge of the insulation pattern  130  for a distance L≧20 μm. Accordingly, it is ensured that the first connection portion  114  is not damaged by an etchant for patterning the first conductive pattern  112  in a subsequent process, namely, the electrical connection between the first connection portion  114  and the first conductive pattern  112  in one first conductive element  110  is ensured. 
     In the present embodiment, the first direction D1 and the second direction D2 are intersected and, for example, perpendicular to each other. Each of the intersection portions  124  of the second conductive element  120  is located in each of the second conductive pattern  122 , and it covers the insulation pattern  130 . Herein, the intersection portion  124  on the insulation pattern  130  is, for example, of a strip having a linewidth W1 satisfying a condition of 100 μm&lt;W1≦300 μm. Since the intersection portion  124  has a sufficient width, the intersection portion  124  may not be completed fractured even if the electrostatic discharge effect occurs on the intersection portion  124  located on the insulation pattern  130 . In other words, the second conductive element  120  of the touch panel  100  may be ensured to maintain its normal performance. In addition, the invention restricts the intersection portion  124  to fall within a range less than or equal to 300 μm, such that influences to the sensing sensitivity of the touch panel due to the parasitic capacitance on the regions where the first conductive elements  110  and the second conductive elements  120  are overlapped being overly great may be prevented. 
     Furthermore, in order to improve a resolution of the touch panel  100 , patterns of the first conductive elements  110  and the second conductive elements  120  may be more complicated. More specific, the second conductive pattern  122  includes two primary conductive patterns  122   a  and the intersection portion  124  located between the two primary conductive patterns  122   a . The intersection portion  124  may be made of the thin metal wire or a material identical to that of the primary conductive pattern  122   a . An accommodating space V is defined between adjacent two of the second conductive patterns  122  and any one of two sides of the second connection portion  122   b . The first conductive pattern  112  may further include a plurality of first conductive branches  112   a  each extended into one of the accommodating spaces V. Therein, a linewidth of the second connection portion  122   b  is represented as W2, in which it satisfies a condition of 20 μm&lt;W2&lt;W1. Accordingly, the capacitance variation provided from the accommodating space V once a finger is laid on is reduced, so as to prevent accuracy of detection of touch from being influenced. Therein, the linewidth of the second connection portion  122   b  is not particularly limited, as long as the linewidth falls within a load range of a control circuit to provide an electrical connection function. 
     In the present embodiment, the substrate  102  is a supporting material and provides a surface on which the first conductive elements  110 , the second conductive elements  120 , the insulation patterns  130 , the signal transmission line  140  and the decoration layer  150  are formed. A part of the first conductive elements  110  or a part of the second conductive elements  120  are extended from the light transmissive region onto the decoration layer  150  to be further away from the substrate  102 , and electrically connected to the signal transmission lines  140  on the decoration layer  150 . The substrate  102  may serve to cover and protect elements at lower portion below, and a side of the substrate  102  where the conductive elements are not disposed can provide an operating interface for users, which includes the surface of the substrate  102  opposite to the surface having the conductive elements formed thereon. That is, in the present embodiment, the substrate  102  may be the cover lens made of a tempered glass or other rigid light transmissive materials. Accordingly, the touch panel  100  may be thinner and lighter. Furthermore, functional layers such as an anti-glare film or an anti-reflection film may be disposed on the surface of the substrate  102  where the conductive elements are not disposed, so that the surface of the outermost functional layer serves as the operating interface for users. Nevertheless, in some embodiments, the substrate  102  may be a color filter substrate, a thin film substrate, an upper cover plate of a display panel or a lower substrate of a display panel. In this case, the first conductive elements  110  and the second conductive elements  120  can be further covered and protected by an anti-scratch protection layer or an additional cover lens. The decoration layer  150  may not be formed on the substrate  102 , for example, it is preferably formed on an inner surface of the additional cover lens rather than the substrate  102 . A surface of the anti-scratch protection layer or the additional cover lens where the conductive elements are not disposed can serve as the operating interface for users. 
     It should be noted that the reference numerals and a part of the contents in the previous embodiment are used in the following embodiments, in which identical reference numerals indicate identical or similar components, and repeated description of the same technical contents is omitted. For a detailed description of the omitted parts, reference can be found in the previous embodiment, and no repeated description is contained in the following embodiments. 
       FIG. 2A  is a schematic top view of a touch panel according to another embodiment of the invention.  FIG. 2B  is a schematic cross-sectional view taken along line C-C′ depicted in  FIG. 2A . Referring to  FIG. 2A  and  FIG. 2B  together, a touch panel  200  includes a plurality of first conductive elements  210  and a plurality of second conductive elements  220  disposed on a substrate  202 . Herein, the signal transmission line is omitted in illustration, and the decoration layer may be selectively formed on the substrate  202 . The first conductive elements  210  and the second conductive elements  220  are intersected with each other. The first conductive element  210  includes a plurality of first conductive patterns  212  and a plurality of first connection portions  214 , which are electrically connected to each other. The first connection portion  214  is disposed between adjacent two of the first conductive patterns  212 . The first connection portions  214  in each first conductive element  210  include first connection patterns  214   a  and second connection patterns  214   b  alternately disposed between adjacent ones of the first conductive patterns  212 . Therein, part of adjacent ones of the first conductive patterns  212  connected together by two or more of the first connection patterns  214   a  disposed therebetween, in which two of the first connection patterns  214   a  encircle an opening  214   c . Above-said disposition has an improved compressive strength and may be more preferably in preventing an open circuit due to breakage of the first connection pattern  214   a  caused by a surge, as in comparison with a disposition using only single one first connection pattern  214   a  to connect the adjacent ones of the first conductive patterns  212 . In the present embodiment, two arc-shaped first connection patterns  214   a  are disposed between adjacent ones of the first conductive patterns  212 , in which a circular opening  214   c  is encircled by adjacent ones of the first connection patterns  214   a  and first conductive patterns  212 . Each insulation pattern  230  covers on the arc-shaped first connection pattern  214   a  and a part of the first conductive pattern  212 ; while the second connection pattern  214   b  is not covered by the insulation pattern  230 . Therein, the second connection pattern  214   b  having a circular profile is capable of reducing overall conduction impedance of the first conductive elements  210 . In the present embodiment, the first conductive patterns  212  may be derived from a rhombus, but the invention is not limited thereto. The first conductive patterns  212  and the first connection portions  214  in each first conductive element  210  are, for example, extended and arranged along a first path P1, and the first path P1 is zigzag. 
     The second conductive element  220  includes a plurality of second conductive patterns  222  and a plurality of second connection portions  224   b , and adjacent two of the second conductive patterns  222  can be electrically connected through one of the second connection portions  224   b . Each of the second conductive patterns  222  has two primary conductive patterns  222   a  and a secondary conductive pattern  222   b . Therein, the secondary conductive pattern  222   b  is disposed between the two primary conductive patterns  222   a , and an area of the secondary conductive pattern  222   b  is less than an area of the primary conductive pattern  222   a . An intersection portion  224   a  is located in the primary conductive pattern  222   a . In the present embodiment, the second connection portion  224   b  may have, for example, a circular profile configured to reduced overall conduction impedance of the second conductive elements  220 . The primary conductive pattern  222   a  may be, for example, derived from a rhombus. The secondary conductive pattern  222   b  may have, for example, a circular profile, but the invention is not limited thereto. The second conductive patterns  222  and the second connection portions  224   b  in each second conductive element  220  are, for example, extended and arranged along a second path P2, and the second path P2 is zigzag. The second path P2 is intersected with the first path P1. 
     The touch panel  200  further includes a plurality of insulation patterns  230 . The insulation patterns  230  are at least disposed at intersections of the first conductive elements  210  and the second conductive elements  220 , so that the first conductive elements  210  are electrically insulated from the second conductive elements  220 . In the present embodiment, each insulation pattern  230  covers the first connection pattern  214   a  and a part of the first conductive pattern  212 , and the intersection portion  224   a  of the second conductive element  220  and a part of the secondary conductive pattern  222   b  are disposed on the insulation pattern  230 . However, in some embodiments, the insulation pattern  230  may be a ring structure only for separating the intersection portion  224   a  from the first connection pattern  214   a , and it is possible not to dispose the secondary conductive pattern  222   b  on the insulation pattern  230 . In addition, the second connection portion  224   b  is not disposed on the insulation pattern  230  but is coplanar to the primary conductive pattern  222   a  instead. 
     As shown in  FIG. 2A , the arc-shaped first connection patterns  214   a  surround the circular secondary conductive pattern  222   b . Therefore, additional amount of fringing capacitance may be provided between the first connection pattern  214   a  and the secondary conductive pattern  222   b , so as to improve mutual induction sensitivity around a position where the first conductive element  210  is intersected with the second conductive element  220 . It should be noted that, although shapes of the first connection pattern  214   a  and the secondary conductive pattern  222   b  are specifically proposed as above, the invention is not limited thereto. In other embodiments, the first connection pattern  214   a  may be a straight linear shape or a polygon, and the secondary conductive pattern  222   b  may be any shapes surrounded by a pattern of a normal projection of the first connection pattern  214   a . Namely, profiles of the first connection pattern  214   a  and the secondary conductive pattern  222   b  are not particularly limited in the invention, and it falls in the scope of the invention for which protection is sought as long as the normal projection of the first connection pattern  214   a  is capable of surrounding the secondary conductive pattern  222   b.    
     As shown in  FIG. 2B , the width of the intersection portion  224   a  located on the insulation pattern  230  is represented as W1, in which it satisfies the condition of 100 μm&lt;W1≦300 μm. In the present embodiment, the width W1 of the intersection portion  224   a  may be slightly larger than a linewidth of the first connection pattern  214   a . Since the width W1 of the intersection portion  224   a  is well controlled, the intersection portion  224   a  has increased resistance to electrostatic discharge, such that the intersection portion  224   a  may not be completed fractured when it suffers damage from electrostatic discharge. In other words, the second conductive element  220  may be ensured to maintain its normal performance. 
     In some other embodiments not illustrated, layers of the first conductive element  210  and the second conductive element  220  depicted in  FIG. 2A  may be inverted. Namely, the conductive elements arranged along the first path P1 in  FIG. 2A  may be rearranged so as to be the second conductive element that partially covers the insulation pattern. Meanwhile, the conductive elements arranged along the first path P2 may be rearranged so as to be the first conductive element partially covered by the insulation pattern. In this case, the intersection portion of the second conductive element is of two arc-shaped patterns, and it is required that a linewidth of the two arc-shaped patterns satisfies a condition of being greater than 100 μm and less than or equal to 300 μm. The second conductive element has only the primary conductive pattern without having the secondary conductive pattern. The first connection pattern and the second connection pattern of the first conductive element are both of a circular shape, and the first connection pattern is surrounded by the normal projection of the intersection portions. 
       FIG. 3A  is a schematic top view of a touch panel according to another embodiment of the invention.  FIG. 3B  is a schematic cross-sectional view taken along line D-D′ depicted in  FIG. 3A . Referring to  FIG. 3A  and  FIG. 3B  together, a touch panel  300  is similar to the touch panel  200  of  FIG. 2A , and a difference thereof is described below. The touch panel  300  includes a plurality of first conductive elements  310  and a plurality of second conductive elements  320  disposed on a substrate  302 . The second conductive element  320  includes a plurality of second conductive patterns  322  and a plurality of second connection portions  324   b , and adjacent ones of the second conductive patterns  322  can be electrically connected through one of the second connection portions  324   b . The second conductive pattern  322  has two primary conductive patterns  322   a , a secondary conductive pattern  322   b , and a hollow portion S. Therein, the secondary conductive pattern  322   b  is disposed between the two primary conductive patterns  322   a , and an area of the secondary conductive pattern  322   b  is less than an area of the primary conductive pattern  322   a . In the present embodiment, the hollow portion S is located in the primary conductive pattern  322   a , and intersection portions  323  are located at two ends of the hollow portion S. A first connection pattern  314  includes a filling section  314   a  and two first intersecting sections  314   b . Therein, the filling section  314   a  is located in the hollow portion S; the first intersecting section  314   b  is intersected with the intersection portion  323 ; and the first intersecting section  314   b  is electrically connected to the filling section  314   a  and the first conductive pattern  312 , as shown in  FIG. 3B . By adopting a pattern design of the hollow portion S and the filling section  314   a , the fringing capacitance of the first connection pattern  314  and the second conductive element  320  may be increased, so as to improve mutual induction sensitivity between the first conductive element  310  and the second conductive element  320 . Specifically, similar to  FIG. 1B , the filling section  314   a  and the first conductive pattern  312  may cover two ends of the first intersecting section  314   b  and extends to cover a part of the insulation pattern  330 . According to this, it can make sure that the first intersecting section  314   b  can prevent damage from the etchant of subsequent patterning of the filling section  314   a  and the first conductive pattern  312 . Therefore, it can make sure that the filling section  314   a  and the first conductive pattern  312  are electrically connected to the first intersecting section  314   b.    
     In the present embodiment, the insulation pattern  330  covers on the first intersecting section  314   b , and the intersection portion  323  is disposed on the insulation portion  330 . Herein, a linewidth of the intersection portion  323  is represented as W1, in which it satisfies the condition of 100 μm&lt;W1≦300 μm. Since the width of the intersection portion  323  is well controlled, the intersection portion  323  has increased resistance to electrostatic discharge, such that the intersection portion  323  may not be completed fractured when it suffers damage from electrostatic discharge. Therefore, the second conductive element  320  of the touch panel  300  may be ensured to maintain its normal performance. In addition, in comparison with the embodiment depicted in  FIG. 2A , the present embodiment may effectively reduce an area of the insulation pattern  330 , and reduce areas where the first connection patterns  314  and the second conductive elements  320  overlap, thereby reducing both the parasitic capacitance and visibility of the intersections of the first conductive elements  310  and the second conductive elements  320 . 
       FIG. 4A  is a schematic top view of a touch panel according to another embodiment of the invention.  FIG. 4B  is an enlarged schematic view of an area M depicted in  FIG. 4A .  FIG. 4C  is a schematic cross-sectional view taken along line E-E′ depicted in  FIG. 4A . Referring to  FIG. 4A ,  FIG. 4B  and  FIG. 4C  together, a touch panel  400  includes a plurality of first conductive elements  410  and a plurality of second conductive elements  420  disposed on a substrate  402 . Herein, the signal transmission line is omitted in illustration, and the decoration layer may be selectively formed on the substrate  402 . The first conductive elements  410  and the second conductive elements  420  are intersected with each other. The first conductive element  410  includes a plurality of first conductive patterns  412  and a plurality of first connection portions  414 . Each of the first connection portions  414  is disposed between and electrically connects adjacent ones of the first conductive patterns  412  together. 
     The touch panel  400  further includes a plurality of insulation patterns  430 . The insulation pattern  430  is disposed at the intersection of the first conductive element  410  and the second conductive element  420 , so that the first conductive element  410  is electrically insulated from the second conductive element  420 . More specifically, the insulation pattern  430  may be disposed on the first connection portion  414  without covering two ends of the first connection portion  414 . The first conductive patterns  412  may cover the two ends of first connection portion  414  to be electrically connected to the first connection portion  414 . 
     In the present embodiment, each second conductive element  420  includes a conductive trunk  422  having a plurality of intersection portions  422   a  intersected with the first connection portions  414 . A linewidth of the conductive trunk  422  is uniform in all portions. Namely, a linewidth W1 of the intersection portion  422   a  is substantially identical to a linewidth of the conductive trunks  422 , and the linewidth of the conductive trunks  422  can also be represented as W1 and satisfy the condition of 100 μm&lt;W1≦300 μm. In consideration of deviation which may occur during actual fabrication, the linewidth W1 may allow a variation within ±5 μm yet still being substantially uniform. For instance, when the linewidth W1 is substantially 125 μm, the linewidth of the conductive trunk  422  may fall within a range of 120 to 130 μm, which is still of the linewidth being substantially uniform. Based on the structure disclosed in the present embodiment, all portions of the conductive trunk  422  have substantially identical linewidth, thus a layout of the second conductive elements  420  may be simpler, and the current crowding effect caused by intensive variations of the linewidth may be reduced. 
     Furthermore, since the conductive trunk  422  has the proper linewidth W1 to cross over the insulation patterns  430 , the intersection portions  422   a  has increased resistance to electrostatic discharge, such that the conductive trunk  422  may not be completed fractured when it suffers damage from electrostatic discharge. Therefore, the second conductive elements  420  of the touch panel  400  may be ensured to maintain its normal performance. In the present embodiment, the conductive trunk  422  is a straight linear pattern. However, in other embodiments, the conductive trunk  422  may also be an irregular linear pattern, and it falls in the scope of the invention for which protection is sought as long as all portions of the conductive trunk  422  have the substantially identical linewidth W1 and in the range of 100 μm&lt;W1≦300 μm. In addition, in the light shielding region, every two of the second conductive elements  420  are electrically connected together through a wire C to constitute a plurality of second conductive groups  420 ′ electrically independent from each other, so as to reduce the conduction impedance of the second conductive elements  420 . A number of the second conductive elements  420  to be electrically connected together is not particularly limited in the invention. In other embodiments, each second conductive group  420 ′ may also be composed of three or more of the second conductive elements  420  parallel connected by the wire C. In addition, in other embodiments, the second conductive elements  420  in the second conductive group  420 ′ may also be driven separately to improve a touch resolution of the touch panel  400 . 
     In addition, the touch panel  400  may further include a plurality of floating dummy electrodes  440  made of a conductive material. The floating dummy electrode  440  is located between the conductive trunk  422  and the first conductive pattern  412 , so as to improve visual effects while reducing a RC loading. In the present embodiment, the floating dummy electrode  440  may has at least one terminal with acute angle. Accordingly, the RC loading may be further reduced to accelerate a charging/discharging speed for loading, so that the touch panel  400  may be suitable applied in high-resolution or large-size touch panels. In a more preferable embodiment, an insulating spacing between one of the conductive trunks  422  and one of the first conductive patterns  412  is full of two of the floating dummy electrodes  422 . In comparison with an embodiment without using the floating dummy electrodes  440  (i.e., there is no floating dummy electrode  422  disposed at the insulating spacing between the conductive trunk  422  and the first conductive pattern  412 ), when the insulating spacing becomes relatively smaller, a capacitance between the conductive trunk  422  and the first conductive pattern  412  becomes relatively greater, while a value of the RC loading also becomes relatively greater; and when the insulating spacing becomes relatively greater, although the RC loading may be reduced, but the first conductive elements  410  and the second conductive elements  420  may prone to be seen. 
       FIG. 5A  is a schematic top view of a touch panel according to another embodiment of the invention.  FIG. 5B  is a schematic cross-sectional view taken along line F-F′ depicted in  FIG. 5A . Referring to  FIG. 5A  and  FIG. 5B , a touch panel  500  includes a plurality of first conductive elements  510  and a plurality of second conductive elements  520  disposed on a substrate  502 . The touch panel  500  is similar to the touch panel  400  depicted in  FIG. 4A , a difference between the two is that, in the touch panel  500 , the first conductive element  510  has two types of first conductive patterns  512 ; and the second conductive elements  520  have two types of conductive trunks  522 . The conductive trunks  522  include first linear patterns  522   a  and second linear patterns  522   b . The first linear pattern  522   a  may be a straight linear pattern, and the second linear pattern  522   b  may be a zigzag linear pattern. Therein, taking one of the first linear patterns  522   a  as a basis, the second linear patterns  522   b  located at two opposite sides of the first linear pattern  522   a  are disposed in a mirror-image relation. Namely, a repeating unit can be composed of three of the conductive trunks  522  including one of the first linear patterns  522   a  and two of the second linear patterns  522   b . In the present embodiment, the first linear pattern  522   a  and the second linear pattern  522   b  have uniform linewidths, respectively, and said linewidths are greater than 100 μm and less than or equal to 300 μm. The linewidth of the first linear pattern  522   a  may be identical to or different from the linewidth of the second linear pattern  522   b . The first conductive patterns  512  of the first conductive element  510  include first sub-patterns  512   a  and second sub-patterns  512   b . The first sub-patterns  512   a  are disposed between adjacent two of the second linear patterns  522   b , and the second sub-patterns  512   b  are disposed between the first linear pattern  522   a  and the second linear pattern  522   b . The first sub-pattern  512   a  is electrically connected to the second sub-pattern  512   b  through a first connection portion  514 . A plurality of insulation patterns  530  are respectively disposed at the intersections of the first conductive elements  510  and the second conductive elements  520  so as to separate the first conductive elements  510  and the second conductive elements  520 . 
     In the present embodiment, each of the conductive trunks  522  of the second conductive elements  522  is connected to a corresponding one of bonding pads  540  through, for example, one of signal transmission lines RX 1  to RX 9  located in the light shielding region, and each of the first conductive elements  510  is connected to a corresponding one of bonding pads  540  through, for example, one of signal transmission lines TX 1  to TX 3  located in the light shielding region. The bonding pads  540  are conducted to pins of a flexible printed circuit board  550 , and a control circuit (not illustrated) may be disposed on the flexible printed circuit board  550  to transmit or receive signals. For instance, the control circuit may transmit driving signals to the signal transmission lines TX 1  to TX 3 , and receive signals from the signal transmission lines RX 1  to RX 9 , but the invention is not limited thereto. 
       FIG. 5C  is a schematic view for electrical connection of the control circuit of the present embodiment. Referring to  FIGS. 5A and 5C , the control circuit of the present embodiment may automatically switch a touch mode between a low resolution and a high resolution based on a type of a touch event (e.g., touched by the finger or touched by the stylus). For instance, when the touch panel  500  is touched by the stylus, the control circuit adopts the high resolution touch mode. In this case, the signals from the signal transmission lines RX 1  to RX 9  are respectively and independently received by the control circuit, so that the touch panel  500  has a resolution of 3×9. When the touch panel  500  is touched by the finger, the control circuit adopts the low resolution touch mode. In this case, the signals from every three adjacent signal transmission lines (RX 1  to RX 3 , RX 4  to EX 6  and RX 7  to RX 9 ) may be simultaneously received by the control circuit, so that the touch panel  500  has a resolution of 3×3. Accordingly, a consumed power of the touch panel  500  may be effectively saved by switching to the low resolution touch mode. 
       FIG. 6  is a schematic top view of a touch panel according to another embodiment of the invention. Referring to  FIG. 6 , a touch panel  600  is similar to the touch panel  500  depicted in  FIG. 5A , a difference between the two is that, every three of the signal transmission lines (e.g., RX 1  to RX 3 , RX 4  to EX 6  and RX 7  to RX 9 ) connected to second conductive elements  620  are connected into a bundle on a substrate  602  and electrically connected to a corresponding one of bonding pads  640 . Conductive trunks  622  of the present embodiment include first linear patterns  622   a  and second linear patterns  622   b . The first linear pattern  622   a  may be a straight linear pattern, and the second linear pattern  622   b  may be a right angle multi-bending linear pattern. A length of the second linear pattern  622   b  may be greater than a length of the first linear pattern  622   a . For decreasing the impedance differences between the second linear pattern  622   b  and the first linear pattern  622   a , optionally, a linewidth of the second linear pattern  622   b  may be less than a linewidth of the first linear pattern  622   a . Therein, taking one of the first linear patterns  622   a  as a basis, the second linear patterns  622   b  located at two opposite sides of the first linear pattern  622   a  are disposed in a mirror-image relation. In the present embodiment, the first conductive patterns  612  of the first conductive element  610  include first sub-patterns  612   a  and second sub-patterns  612   b . The first sub-patterns  612   a  are disposed between adjacent two of the second linear patterns  622   b , and the second sub-patterns  612   b  are disposed between the first linear pattern  622   a  and the second linear pattern  622   b . The first sub-pattern  612   a  is electrically connected to the second sub-pattern  612   b  through a first connection portion  614 . A plurality of insulation patterns  630  are respectively disposed at regions where the first conductive elements  610  and the second conductive element  620  are intersected with other so as to separate the first conductive elements  610  and the second conductive elements  620 . 
       FIG. 7  is a schematic top view of a touch panel according to another embodiment of the invention. Referring to  FIG. 7 , a touch panel  700  is similar to the touch panel  400 , a difference between the two is that, each second conductive element  720  of the touch panel  700  further includes a plurality of second conductive branches  724 . The second conductive branches  724  are extruded from two opposite sides of a conductive trunk  722 , and surrounded by the first conductive pattern  712  of the first conductive element  710 . The adjacent first conductive patterns  712  are electrically connected to each other through a first connection portion  714 . From another perspective, the first conductive pattern  712  includes an opening having a special arrangement design, and the second conductive branch  724  is, for example, disposed in the opening of the first conductive pattern  712 . An arrangement of the second conductive branch  724  is complementary to a profile of the opening of the first conductive pattern  712 . As shown in  FIG. 7 , the second conductive branch  724  is arranged in a rectangular spiral shape, such that the opening of the first conductive pattern  712  is arranged in a corresponding rectangular spiral shape suitable for accommodating the second conductive branch  724 . By adopting the second conductive branches  724 , the touch panel  700  may provide a favorable sensing sensitivity and linearity. Of course, shapes for the arrangements of the first conductive pattern  712  and the second conductive branches  724  are not particularly limited in the invention as long as the shapes for the arrangements of the two are complementary. In order to accomplish the purpose of the invention, a linewidth W1 of the conductive trunk  722  is greater than 100 μm and less than or equal to 300 μm. Furthermore, the second conductive branches  724  can also have a uniform linewidth W3, in which the linewidth W3 can be not greater than the linewidth W1 of the conductive trunk  722 . 
       FIG. 8  is a schematic top view of a touch panel according to another embodiment of the invention. Referring to  FIG. 8 , a touch panel  800  is similar to the touch panel  700 , a difference between the two is that, a second conductive element  820  of the touch panel  800  includes a plurality of second conductive branches  824 , and the second conductive branches  824  are of, for example, a straight linear shape. Each of the second conductive branches  824  is outwardly extruded from a conductive trunk  822  and inwardly extended into notches of the first conductive pattern  812  of the first conductive element  810 . The adjacent first conductive patterns  812  are electrically connected to each other through a first connection portion  814 . An extending direction of the second conductive branch  824  is not parallel to an extending direction of the conductive trunk  822 . As similar to that in the foregoing embodiments, by adopting the second conductive branches  824 , the touch panel  800  may provide a favorable sensing sensitivity and linearity. 
     In summary, in the touch panel according to the embodiments of the invention, the linewidth of the second conductive element located on the insulation pattern is controlled to fall within an appropriate range, so that the second conductive element is not easily broken even if the second conductive element on the insulation pattern suffers damage from the electrostatic discharge, thereby ensuring that the touch panel may provide a favorable performance. In addition, in the touch panel according to one of the embodiments of the invention, the second conductive element may have a conductive trunk with a uniform linewidth, so that the current crowding effect may be reduced, and fabrication may be easier by a simpler arrangement.