PATENT DOCUMENT

Publication Number: US-10521049-B2
Application Number: US-201816144911-A
Country: US
Kind Code: B2

Title: Multi-via structures for touchscreens

Abstract:
The disclosure relates to a touch screen including a first electrode layer, a second electrode layer, and a third electrode layer. The touch screen can include shield-sensor vias connecting the first electrode layer and the second electrode layer and shield-shield vias connecting the first electrode layer and the third electrode layer, for example. The shield-sensor vias can be placed in a bond pad region of the touch screen, which can further include connections between one or more routing traces connected to one or more touch electrodes and touch or other circuitry further included in the electronic device. The shield-shield vias can be placed in an outer region located around an inner region of the touch screen. In some examples, one or more routing traces can include diverted portions to maintain a threshold distance between the routing traces and the one or more shield-shield vias.

Claims:
What is claimed is: 
     
       1. A touch sensor panel comprising:
 a first electrode layer comprising a first shielding electrode; 
 a second electrode layer comprising one or more touch electrodes coupled to one or more routing traces; a third electrode layer comprising a second shielding electrode; 
 a bond pad region comprising a plurality of connections to the one or more routing traces, the connections in the bond pad region different from connections between the one or more routing traces and the one or more touch electrodes; 
 a plurality of vias comprising:
 one or more first vias electrically coupling the first electrode layer and the second electrode layer, the one or more first vias placed within the bond pad region; and 
 one or more second vias electrically coupling the first electrode layer and the third electrode layer, wherein the first electrode layer and the third electrode layer are disposed above and below the second electrode layer, respectively. 
 
 
     
     
       2. The touch sensor panel of  claim 1 , wherein the one or more routing traces are coupled to touch sensing circuitry by way of the connections in the bond pad region. 
     
     
       3. The touch sensor panel of  claim 1 , wherein:
 each of the one or more routing traces comprises a first conductive portion in an inner region of the touch sensor panel and a second conductive portion in an outer region of the touch sensor panel, the outer region located around the inner region, wherein: 
 the first conductive portions have a lower conductivity than the second conductive portions, and 
 the one or more second vias are located in the outer region. 
 
     
     
       4. The touch sensor panel of  claim 3 , wherein:
 the one or more routing traces comprises a first routing trace coupled to a first touch electrode, 
 the first touch electrode is a first distance from one of the one or more second vias, 
 the first conductive portion of the first routing trace is longer than the first distance such that the first routing trace is separated from the one of the one or more second vias by at least a threshold distance. 
 
     
     
       5. The touch sensor panel of  claim 3 , wherein:
 the one or more routing traces comprises a first routing trace coupled to a first touch electrode, 
 the first touch electrode is a first distance from one of the one or more second vias, 
 the first routing trace further comprises a third conductive portion, the one of the one or more second vias placed between the third conductive portion and the second conductive portion, 
 the first conductive portion of the first routing trace comprises a diverted portion connected to the second conductive portion and the third conductive portion such that the first routing trace is separated from the one of the one or more second vias by at least a threshold distance. 
 
     
     
       6. The touch sensor panel of  claim 3 , wherein the first conductive portions include ITO and the second conductive portions include copper. 
     
     
       7. The touch sensor panel of  claim 1 , further comprising:
 an inner region, the inner region including the one or more touch electrodes; and 
 a first opaque mask around the inner region, the first opaque mask comprising one or more notches, wherein the one or more second vias are placed in the one or more notches of the first opaque mask. 
 
     
     
       8. The touch sensor panel of  claim 7 , further comprising:
 a cover material located on an opposite side of the first electrode layer than the second electrode layer; and 
 a second opaque mask placed on the cover material, the second opaque mask having an interior edge and an exterior edge, the interior edge located further from the one or more touch electrodes than an interior edge of the first opaque mask. 
 
     
     
       9. The touch sensor panel of  claim 7 , wherein:
 one or more of the first electrode layer, the second electrode layer, and the third electrode layer include one or more tabs extending outward at radial locations of the touch sensor panel having the one or more notches of the first opaque mask. 
 
     
     
       10. The touch sensor panel of  claim 1 , further comprising:
 a passivation layer placed on the first electrode layer and second electrode layer such that the first electrode layer is between the passivation layer and the second electrode layer, wherein:
 the first electrode layer includes a first hole, 
 the second electrode layer includes a second hole, 
 the passivation layer includes a third hole larger than the first hole, 
 the first hole, second hole, and third hole overlap one another, and 
 at least one of the one or more first vias placed within the first hole, second hole, and third hole comprises an endcap in contact with the first electrode layer, the endcap overlapping a region of the first electrode layer exposed by the third hole in the passivation layer. 
 
 
     
     
       11. The touch sensor panel of  claim 1 , further comprising:
 a passivation layer placed on the first electrode layer and the second electrode layer such that the second electrode layer is located between the passivation layer and the first electrode layer; and 
 a conformal layer on the second electrode layer and the passivation layer, wherein:
 the first electrode layer includes a first hole, 
 the second electrode layer includes a second hole, 
 the passivation layer includes a third hole larger than the second hole, 
 the first hole, second hole, and third hole overlap one another, 
 one of the one or more first vias placed within the first hole, the second hole, and the third hole comprises an endcap in contact with the second electrode layer, 
 the second electrode layer comprises an exposed region between the endcap and the passivation layer, and 
 the conformal layer completely overlaps the exposed region of the second electrode layer. 
 
 
     
     
       12. The touch sensor panel of  claim 1 , wherein:
 the one or more second vias are oval vias having an extended structure in one dimension. 
 
     
     
       13. A method of sensing touch at a touch sensor panel, the method comprising:
 shielding noise using a first shielding electrode placed on a first electrode layer; 
 sensing touch using one or more touch electrodes placed on a second electrode layer; 
 shielding noise using a second shielding electrode placed on a third electrode layer; 
 connecting, using one or more routing traces included in the second electrode layer, the one or more touch electrodes to one or more bond pad regions; 
 electrically coupling, using one or more first vias placed in the one or more bond pad regions, the first electrode layer and the second electrode layer; 
 electrically coupling, using one or more second vias placed outside the bond pad region, the first electrode layer and the third electrode layer; and 
 driving the first, second, and third electrode layers to a same potential, 
 wherein the first electrode layer and the third electrode layer are disposed above and below the second electrode layer, respectively. 
 
     
     
       14. The method of  claim 13 , further comprising:
 sensing touch using touch sensing circuitry coupled to the one or more routing traces by way of one or more connections within the one or more bond pad regions. 
 
     
     
       15. The method of  claim 13 , further comprising:
 routing one or more signals from the one or more touch electrodes using the one or more routing traces coupled to the one or more touch electrodes, each routing trace comprising a first conductive portion in an inner region of the touch sensor panel and a second conductive portion in an outer region of the touch sensor panel, the outer region around the inner region, wherein: 
 the first conductive portion has a lower conductivity than the second conductive portion, and 
 the one or more second vias are located in the outer region. 
 
     
     
       16. The method of  claim 15 , wherein:
 the one or more routing traces comprises a first routing trace coupled to a first touch electrode, 
 the first touch electrode is located a first distance from one of the one or more second vias, 
 the first routing trace further comprises a third conductive portion, the one of the one or more second vias placed between a first metal portion and a second metal portion of the first routing trace, 
 the first conductive portion of the first routing trace comprises a diverted portion connected to the second conductive portion and the third conductive portion such that the first routing trace is separated from the one of the one or more second vias by at least a threshold distance. 
 
     
     
       17. The method of  claim 15 , wherein the first conductive portion includes ITO and the second conductive portion includes copper. 
     
     
       18. The method of  claim 13 , wherein:
 the one or more touch electrodes are placed within an inner region of the touch sensor panel, 
 a first opaque mask is located around the inner region, 
 the first opaque mask comprises one or more notches, and 
 the one or more second vias are placed in the one or more notches of the first opaque mask. 
 
     
     
       19. The method of  claim 18 , further comprising:
 covering, with a cover material overlapping the inner region and the first opaque mask, the first electrode layer, the second electrode layer, and the third electrode layer, wherein a second opaque mask is placed on the cover material, the second opaque mask having an interior edge and an exterior edge, the interior edge located further from the one or more touch electrodes than an interior edge of the first opaque mask. 
 
     
     
       20. The method of  claim 13 , further comprising:
 covering the first electrode layer and the second electrode layer with a passivation layer such that the first electrode layer is located between the passivation layer and the second electrode layer, wherein:
 the first electrode layer includes a first hole, 
 the second electrode layer includes a second hole, 
 the passivation layer includes a third hole larger than the first hole, 
 the first hole, the second hole, and the third hole overlap one another, and 
 one of the one or more first vias placed within the first hole, the second hole, and the third hole comprises an endcap in contact with the first electrode layer, the endcap overlapping a region of the first electrode layer exposed by the third hole in the passivation layer. 
 
 
     
     
       21. The method of  claim 13 , further comprising:
 covering the first electrode layer and the second electrode layer with a passivation layer such that the second electrode layer is between the passivation layer and the second electrode layer, wherein:
 the first electrode layer includes a first hole, 
 the second electrode layer includes a second hole, 
 the passivation layer includes a third hole larger than the second hole, 
 the first hole, the second hole, and the third hole overlap one another, 
 one of the one or more first vias placed within the first hole, the second hole, and the third hole comprises an endcap in contact with the second electrode layer, 
 the second electrode layer comprises an exposed region between the endcap and the passivation layer, and 
 a conformal layer placed on the second electrode layer and the passivation layer that overlaps the exposed region of the second electrode layer. 
 
 
     
     
       22. A method of forming a touch sensor panel, the method comprising:
 forming a first shielding electrode on a first electrode layer; forming one or more touch electrodes on a second electrode layer; 
 forming a second shielding electrode on a third electrode layer; 
 forming one or more routing traces coupled to the one or more touch electrodes; 
 forming a bond pad region comprising connections to the one or more routing traces, the connections in the bond pad region different from connections between the one or more routing traces and the one or more touch electrodes; 
 forming, in the bond pad region, one or more first vias electrically coupling the first electrode layer and the second electrode layer; and 
 forming one or more second vias electrically coupling the first electrode layer and the third electrode layer, wherein the first electrode layer and the third electrode layer are disposed above and below the second electrode layer, respectively. 
 
     
     
       23. The method of  claim 22 , wherein the one or more routing traces are coupled to touch sensing circuitry by way of the connections in the bond pad region. 
     
     
       24. The method of  claim 22 , wherein:
 each of the one or more routing traces comprises a first conductive portion in an inner region of the touch sensor panel and a second conductive portion in an outer region of the touch sensor panel, the outer region located around the inner region, wherein: 
 the first conductive portion has a lower conductivity than the second conductive portion, and 
 the one or more second vias are located in the outer region. 
 
     
     
       25. The method of  claim 24 , wherein:
 the one or more routing traces comprises a first routing trace coupled to a first touch electrode, 
 the first touch electrode is a first distance from one of the one or more second vias, 
 the first conductive portion of the first routing trace is longer than the first distance such that the first routing trace is separated from the one of the one or more second vias by at least a threshold distance. 
 
     
     
       26. The method of  claim 24 , wherein:
 the one or more routing traces comprises a first routing trace coupled to a first touch electrode, 
 the first touch electrode is a first distance from one of the one or more second vias, 
 the first routing trace further comprises third conductive portion, the one of the one or more second vias placed between the second conductive portion and the third conductive portion, 
 the first conductive portion of the first routing trace comprises a diverted portion connected to the second conductive portion and the third conductive portion such that the first routing trace is separated from the one of the one or more second vias by at least a threshold distance. 
 
     
     
       27. The method of  claim 26 , wherein the first conductive portion comprises ITO and the second conductive portion comprises copper. 
     
     
       28. The method of  claim 22 , further comprising:
 forming an inner region, the inner region including the one or more touch electrodes; 
 forming a first opaque mask around the inner region, the first opaque mask comprising one or more recessed notches, wherein the one or more second vias are placed in the recessed notches of the first opaque mask. 
 
     
     
       29. The method of  claim 28 , further comprising:
 forming a cover material located on an opposite side of the first electrode layer than the second electrode layer; and 
 forming a second opaque mask placed on the cover material, the second opaque mask having an interior edge and an exterior edge, the interior edge located further from the one or more touch electrodes than an interior edge of the first opaque mask. 
 
     
     
       30. The method of  claim 22 , further comprising:
 forming a passivation layer placed on the first electrode layer and second electrode layer such that the first electrode layer is between the passivation layer and the second electrode layer, wherein:
 the first electrode layer includes a first hole, 
 the second electrode layer includes a second hole, 
 the passivation layer includes a third hole larger than the first hole, 
 the first hole, second hole, and third hole overlap one another, and 
 at least one of the one or more first vias placed within the first hole, second hole and third hole comprises an endcap in contact with the first electrode layer, the endcap overlapping a region of the first electrode layer exposed by the third hole in the passivation layer. 
 
 
     
     
       31. The method of  claim 22 , further comprising:
 forming a passivation layer placed on the first electrode layer and the second electrode layer such that the second electrode layer is located between the passivation layer and the first electrode layer; and 
 forming a conformal layer on the second electrode layer and the passivation layer, wherein:
 the first electrode layer includes a first hole, 
 the second electrode layer includes a second hole, 
 the passivation layer includes a third hole larger than the second hole, 
 the first hole, second hole, and third hole overlap one another, 
 one of the one or more first vias placed within the first hole, the second hole, and the third hole comprises an endcap in contact with the second electrode layer, 
 the second electrode layer comprises an exposed region between the endcap and the passivation layer, and 
 the conformal layer completely overlaps the exposed region of the second electrode layer.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 USC 119(e) of U.S. Provisional Patent Application No. 62/565,531, filed Sep. 29, 2017 and the contents of which are incorporated herein by reference in their entirety for all purposes. 
    
    
     FIELD OF DISCLOSURE 
     This relates to a touch screen including a plurality of electrode layers, and more particularly, to a touch screen comprising a stackup including a plurality of electrode layers electrically coupled together using one or more types of vias. 
     BACKGROUND OF THE DISCLOSURE 
     Many types of input devices are presently available for performing operations in a computing system, such as buttons or keys, mice, trackballs, joysticks, touch sensor panels, touch screens, and the like. Touch screens, in particular, are popular because of their ease and versatility of operation as well as their declining price. Touch screens can include a touch sensor panel, which can be a transparent panel with a touch-sensitive surface, and a display device such as a liquid crystal display (LCD), light emitting diode (LED) display or organic light emitting diode (OLED) display that can be positioned partially or fully behind the panel so that the touch-sensitive surface can cover at least a portion of the viewable area of the display device. Touch screens can allow a user to perform various functions by touching the touch sensor panel using a finger, stylus, or other touch object at a location often dictated by a user interface (UI) being displayed by the display device. In general, touch screens can recognize a touch and the position of the touch on the touch sensor panel. The computing system can interpret the touch in accordance with one or more display images appearing at the time of the touch. The touch screen can perform one or more actions based on the touch. In the case of some touch screens, a physical touch on the display may not be needed to detect a touch. For example, in some capacitive-type touch screens, fringing electrical fields used to detect touch can extend beyond the surface of the display, and an touch object approaching near the surface may be detected near the surface without actually touching the surface. 
     Capacitive touch sensor panels can be formed by a matrix of partially or fully transparent or non-transparent conductive plates (e.g., touch electrodes) made of materials such as Indium Tin Oxide (ITO). In some examples, the conductive plates can be formed from other materials including conductive polymers, metal mesh, graphene, nanowires (e.g., silver nanowires) or nanotubes (e.g., carbon nanotubes). In order to detect such changes, in some examples, the touch electrodes can be coupled to sense circuitry using routing traces. It is due in part to their substantial transparency that some capacitive touch sensor panels can be overlaid on a display to form a touch screen. Some touch screens can be formed by at least partially integrating touch sensing circuitry into a display pixel stackup (i.e., a stack of material layers forming the display pixels). In some examples, touch screens can further include one or more shielding electrodes for mitigating the capacitive coupling of electrical noise to one or more touch sensing components (e.g., touch electrodes or routing traces) of the touch screen. The shielding electrodes can be located on the same layer or on different layers from the touch electrodes and/or routing traces and can receive a same or different signal from the signal applied to the touch electrodes (e.g., by way of routing traces) to sense a touch. 
     BRIEF SUMMARY OF THE INVENTION 
     This relates to a touch screen including a plurality of electrode layers and to a touch screen whose stackup can include a plurality of electrode layers electrically coupled together using one or more types of vias. In some examples, the touch screen can include a top shielding layer, a touch sensing layer, and a bottom shielding layer. In some examples, the top shielding layer, the bottom shielding layer, and one or more electrodes located on the touch sensing layer can be driven with one or more electrical signals to mitigate unwanted capacitive coupling to one or more electronic components (e.g., the touch electrodes and/or one or more routing traces). The top shielding layer and the touch sensing layer can be electrically coupled by one or more shield-sensor vias, for example. In some examples, the top shielding layer and the bottom shielding layer can be coupled by one or more shield-shield vias. In this way, the top shielding layer, the touch sensing layer, and the bottom shielding layer can be electrically coupled together so that the three layers can be driven with the same electric potential. 
     The different types of vias can be located in regions of the touch screen based on the exposure of electrode layers such that an endcap (e.g., a part of a via in contact with a surface of an electrode layer), included in the via, can make electrical contact with the respective electrode layer. For example, a shield-sensor via can be located in a region (e.g., a bond pad region) where the top shielding and touch layers are both exposed. A shield-shield via can be located in a different region (e.g., an edge region or a border region) where the top and bottom shielding layers are exposed. The touch screen can include on or more opaque masks to reduce the visibility of electronic components (e.g., routing traces). To reduce the visibility of the vias, the vias can be further located in areas covered by an opaque mask. In some examples, the touch screen can include one or more passivation layers to reduce or prevent corrosion of the vias. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A-1D  illustrate an example mobile telephone, an example media player, an example personal computer, and an example tablet computer that can each include an exemplary touch screen according to examples of the disclosure. 
         FIG. 2  illustrates a block diagram of an example computing system that illustrates one implementation of an example self-capacitance touch screen according to examples of the disclosure. 
         FIG. 3A  illustrates an exemplary touch sensor circuit corresponding to a self-capacitance touch electrode and sensing circuit according to examples of the disclosure. 
         FIG. 3B  illustrates an exemplary touch sensor circuit corresponding to a mutual-capacitance drive and sense lines and sensing circuit according to examples of the disclosure. 
         FIG. 4A  illustrates a top view of an exemplary touch screen including touch electrodes arranged in rows and columns according to examples of the disclosure. 
         FIG. 4B  illustrates a top view of an exemplary touch screen including touch electrodes arranged in a pixelated touch electrode configuration according to examples of the disclosure. 
         FIG. 5A  illustrates a top view of an exemplary touch sensing layer included in a touch screen according to examples of the disclosure. 
         FIG. 5B  illustrates a top view of a section of an exemplary top shielding electrode on top of a touch sensing layer included in a touch screen according to examples of the disclosure. 
         FIG. 6A  illustrates top views of a plurality of electrode layers included in an exemplary touch screen according to examples of the disclosure. 
         FIGS. 6B-6C  illustrate cross-sectional views of a plurality of electrode layers as arranged in an exemplary touch screen according to examples of the disclosure. 
         FIGS. 7A-B  illustrate a top view of a portion of an exemplary electronic device including bond pad regions and vias according to examples of the disclosure. 
         FIGS. 7C-7F  illustrate top views of exemplary touch screens including routing traces having diverted portions according to examples of the disclosure. 
         FIG. 8  illustrates a cross-sectional view of a portion of an exemplary touch screen including a cover material, a first opaque mask, and a second opaque mask according to examples of the disclosure. 
         FIGS. 9A-9D  illustrate cross-sectional views of an exemplary touch screen including vias coupling a plurality of electrode layers according to examples of the disclosure. 
         FIGS. 10A-10F  illustrate cross-sectional views of an exemplary touch screen during a manufacturing process according to examples of the disclosure. 
         FIG. 11  illustrates an exemplary process flow for forming a touch screen according to examples of the disclosure. 
         FIGS. 12A-B  illustrate cross-sectional views of a portion of an exemplary touch screen including passivation layers and a via between electrode layers according to examples of the disclosure. 
         FIGS. 13A-13D  illustrate cross-sectional views of a portion of an exemplary touch screen including passivation layers and a via between electrode layers during a manufacturing process according to examples of the disclosure. 
         FIGS. 14A-14D  illustrate cross-sectional views of a portion of an exemplary touch screen including passivation layers and a via between electrode layers during a manufacturing process according to examples of the disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following description of examples, reference is made to the accompanying drawings which form a part hereof, and in which it is shown by way of illustration specific examples that can be practiced. It is to be understood that other examples can be used and structural changes can be made without departing from the scope of the disclosed examples. 
     This relates to a touch screen including a plurality of electrode layers and to a touch screen whose stackup can include a plurality of electrode layers electrically coupled together using one or more types of vias. In some examples, the touch screen can include a top shielding layer, a touch sensing layer, and a bottom shielding layer. In some examples, the top shielding layer, the bottom shielding layer, and one or more electrodes located on the touch sensing layer can be driven with one or more electrical signals to mitigate unwanted capacitive coupling to one or more electronic components (e.g., the touch electrodes and/or one or more routing traces). The top shielding layer and the touch sensing layer can be electrically coupled by one or more shield-sensor vias, for example. In some examples, the top shielding layer and the bottom shielding layer can be coupled by one or more shield-shield vias. In this way, the top shielding layer, the touch sensing layer, and the bottom shielding layer can be electrically coupled together so that the three layers can be driven with the same electric potential. 
     The different types of vias can be located in regions of the touch screen based on the exposure of electrode layers such that an endcap (e.g., a part of a via in contact with a surface of an electrode layer), included in the via, can make electrical contact with the respective electrode layer. For example, a shield-sensor via can be located in a region (e.g., a bond pad region) where the top shielding and touch layers are both exposed. A shield-shield via can be located in a different region (e.g., an edge region or a border region) where the top and bottom shielding layers are exposed. The touch screen can include on or more opaque masks to reduce the visibility of electronic components (e.g., routing traces). To reduce the visibility of the vias, the vias can be further located in areas covered by an opaque mask. In some examples, the touch screen can include one or more passivation layers to reduce or prevent corrosion of the vias. 
       FIGS. 1A-1D  illustrate an example mobile telephone  136 , an example media player  140 , an example personal computer  144 , and an example tablet computer  148  that can each include an exemplary touch screen  124 - 128  according to examples of the disclosure. 
       FIG. 1A  illustrates an example mobile telephone  136  that includes a touch screen  124 .  FIG. 1B  illustrates an example digital media player  140  that includes a touch screen  126 .  FIG. 1C  illustrates an example personal computer  144  that includes a touch screen  128 .  FIG. 1D  illustrates an example tablet computer  148  that includes a touch screen  130 . It is understood that the above touch screens can be implemented in other devices as well, including in wearable devices. 
     In some examples, touch screens  124 ,  126 ,  128 , and  130  can be based on self-capacitance. A self-capacitance-based touch system can include a matrix of small, individual plates of conductive material that can be referred to as touch electrodes (as described below with reference to touch screen  220  in  FIG. 2  and with reference to touch screen  402  in  FIG. 4B ). For example, a touch screen can include a plurality of individual touch electrodes, where each touch electrode can identify or represent a unique location on the touch screen at which touch or proximity (i.e., a touch or proximity event) can be sensed. In some instances, one or more touch electrodes can be electrically isolated from other touch electrodes in the touch screen. Such a touch screen can be referred to as a pixelated self-capacitance touch screen, though it is understood that, in some examples, the touch electrodes on the touch screen can be used to perform scans other than self-capacitance scans on the touch screen (e.g., mutual capacitance scans). During operation, a touch electrode can be stimulated with an AC waveform, and the self-capacitance to ground of the touch electrode can be measured. As a touch object approaches the touch electrode, the self-capacitance to ground of the touch electrode can change (e.g., increase). This change in the self-capacitance of the touch electrode can be detected and measured by the touch screen to determine the positions of multiple touch objects when they touch, or come in proximity to, the touch screen. In some examples, the touch electrodes of a self-capacitance-based touch system can be formed from rows and columns of conductive material (as described below with reference to touch screen  400  in FIG.  4 A), and changes in the self-capacitance to ground of the rows and columns can be detected, similar to above. In some examples, a touch screen can be multi-touch, single touch, projection scan, full-imaging multi-touch, capacitive touch, etc. 
     In some examples, touch screens  124 ,  126 ,  128 , and  130  can be based on mutual capacitance. A mutual capacitance-based touch system can include drive and sense lines that may cross over each other on different layers, or may be adjacent to each other on the same layer. The crossing or adjacent locations can be referred to as touch nodes. During operation, the drive line can be stimulated with an AC waveform and the mutual capacitance of the touch node can be measured. As a touch object approaches the touch node, the mutual capacitance of the touch node can change (e.g., decrease). This change in the mutual capacitance of the touch node can be detected and measured by the touch screen to determine the positions of multiple touch objects when they touch or come in proximity to, the touch screen. Although examples of touch screens are described herein, it should be understood that some examples can include touch sensor panels associated with a display screen (e.g., touch sensitive displays) or not associated with a display screen (e.g., trackpads) without departing from the scope of the disclosure. In some examples, the electrodes of a mutual-capacitance based touch system can be formed from a matrix of small, individual plates of conductive material, and changes in the mutual capacitance between plates of conductive material can be detected, similar to above. 
     In some examples, touch screens  124 ,  126 ,  128  and  130  can be based on mutual capacitance and/or self-capacitance. The electrodes can be arrange as a matrix of small, individual plates of conductive material (e.g., as in touch screen  402  in  FIG. 4B ) or as drive lines and sense lines (e.g., as in touch screen  400  in  FIG. 4B ), or in another pattern. The electrodes can be configurable for mutual capacitance or self-capacitance sensing or a combination of mutual and self-capacitance sensing. For example, in one mode of operation electrodes can be configured to sense mutual capacitance between electrodes and in a different mode of operation electrodes can be configured to sense self-capacitance of electrodes. In some examples, some of the electrodes can be configured to sense mutual capacitance therebetween and some of the electrodes can be configured to sense self-capacitance thereof. 
       FIG. 2  illustrates a block diagram of an example computing system  200  that illustrates one implementation of an example self-capacitance touch screen  220  according to examples of the disclosure. It is understood that computing system  200  can include a mutual capacitance touch screen, as described above, though the examples of the disclosure will be described in the context of a self-capacitance touch screen. Computing system  200  can be included in, for example, mobile telephone  136 , digital media player  140 , personal computer  144 , tablet computer  148 , or any mobile or non-mobile computing device that includes a touch screen such as a wearable device. Computing system  200  can include a touch screen including one or more touch processors  202 , peripherals  204 , a touch controller  206 , and touch sensing circuitry (described in more detail below). Peripherals  204  can include, but are not limited to, random access memory (RAM) or other types of memory or storage, watchdog timers, and the like. Touch controller  206  can include, but is not limited to, one or more sense channels  208  and channel scan logic  210 . Channel scan logic  210  can access RAM  212 , autonomously read data from sense channels  208 , and provide control for the sense channels. In addition, channel scan logic  210  can control sense channels  208  to generate stimulation signals at various frequencies and phases that can be selectively applied to the touch nodes of touch screen  220 , as described in more detail below. In some examples, touch controller  206 , touch processor  202 , and peripherals  204  can be integrated into a single application specific integrated circuit (ASIC), and in some examples, can be integrated within touch screen  220  itself. 
     Touch screen  220  can be used to derive touch information at multiple discrete locations of the touch screen, referred to herein as touch nodes. For example, touch screen  220  can include touch sensing circuitry that can include a capacitive sensing medium having a plurality of electrically isolated touch node electrodes  222  (e.g., a plurality of touch node electrodes of pixelated self-capacitance touch screen). Touch node electrodes  222  can be coupled to sense channels  208  in touch controller  206 , can be driven by stimulation signals from the sense channels through drive/sense interface  225 , and can be sensed by the sense channels through the drive/sense interface as well, as described above. As used herein, an electrical component “coupled to” or “connected to” another electrical component encompasses a direct or indirect connection providing electrical path for communication or operation between the coupled components. Thus, for example, touch node electrodes  222  may be directly connected to sense channels or indirectly connected to sense channels via drive/sense interface  225 , but in either case provided an electrical path for driving and/or sensing the touch node electrodes  222 . Labeling the conductive plates used to detect touch (i.e., touch node electrodes  222 ) as “touch node” electrodes can be particularly useful when touch screen  220  is viewed as capturing an “image” of touch (e.g., a “touch image”). In other words, after touch controller  206  has determined an amount of touch detected at each touch node electrode  222  in touch screen  220 , the pattern of touch node electrodes in the touch screen at which a touch occurred can be thought of as a touch image (e.g., a pattern of fingers touching the touch screen). In such examples, each touch node electrode in a pixelated self-capacitance touch screen can be sensed for the corresponding touch node represented in the touch image. 
     Computing system  200  can also include a host processor  228  for receiving outputs from touch processor  202  and performing actions based on the outputs. For example, host processor  228  can be connected to program storage  232  and a display controller, such as an LCD driver  234  (or an LED display or OLED display driver). The LCD driver  234  can provide voltages on select (e.g., gate) lines to each pixel transistor and can provide data signals along data lines to these same transistors to control the pixel display image as described in more detail below. Host processor  228  can use LCD driver  234  to generate a display image on touch screen  220 , such as a display image of a user interface (UI), and can use touch processor  202  and touch controller  206  to detect a touch on or near touch screen  220 . The touch input can be used by computer programs stored in program storage  232  to perform actions that can include, but are not limited to, moving an touch object such as a cursor or pointer, scrolling or panning, adjusting control settings, opening a file or document, viewing a menu, making a selection, executing instructions, operating a peripheral device connected to the host device, answering a telephone call, placing a telephone call, terminating a telephone call, changing the volume or audio settings, storing information related to telephone communications such as addresses, frequently dialed numbers, received calls, missed calls, logging onto a computer or a computer network, permitting authorized individuals access to restricted areas of the computer or computer network, loading a user profile associated with a user&#39;s preferred arrangement of the computer desktop, permitting access to web content, launching a particular program, encrypting or decoding a message, and/or the like. Host processor  228  can also perform additional functions that may not be related to touch processing. 
     Note that one or more of the functions described herein, including the configuration of switches, can be performed by firmware stored in memory (e.g., one of the peripherals  204  in  FIG. 2 ) and executed by touch processor  202 , or stored in program storage  232  and executed by host processor  228 . The firmware can also be stored and/or transported within any non-transitory computer-readable storage medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “non-transitory computer-readable storage medium” can be any medium (excluding signals) that can contain or store the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, a portable computer diskette (magnetic), a random access memory (RAM) (magnetic), a read-only memory (ROM) (magnetic), an erasable programmable read-only memory (EPROM) (magnetic), a portable optical disc such a CD, CD-R, CD-RW, DVD, DVD-R, or DVD-RW, or flash memory such as compact flash cards, secured digital cards, USB memory devices, memory sticks, and the like. 
     The firmware can also be propagated within any transport medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “transport medium” can be any medium that can communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The transport medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, or infrared wired or wireless propagation medium. 
       FIG. 3A  illustrates an exemplary touch sensor circuit  300  corresponding to a self-capacitance touch node electrode  302  and sensing circuit  314  according to examples of the disclosure. Touch node electrode  302  can correspond to touch node electrode  222 . Touch node electrode  302  can have an inherent self-capacitance to ground associated with it, and also an additional self-capacitance to ground that is formed when an object, such as finger  305 , is in proximity to or touching the electrode. The total self-capacitance to ground of touch node electrode  302  can be illustrated as capacitance  304 . Touch node electrode  302  can be coupled to sensing circuit  314 . Sensing circuit  314  can include an operational amplifier  308 , feedback resistor  312  and feedback capacitor  310 , although other configurations can be employed. For example, feedback resistor  312  can be replaced by a switched capacitor resistor in order to minimize a parasitic capacitance effect that can be caused by a variable feedback resistor. Touch node electrode  302  can be coupled to the inverting input (−) of operational amplifier  308 . An AC voltage source  306  (V ac ) can be coupled to the non-inverting input (+) of operational amplifier  308 . Touch sensor circuit  300  can be configured to sense changes in the total self-capacitance  304  of the touch node electrode  302  induced by a finger or object either touching or in proximity to the touch sensor panel. Output  320  can be used by a processor to determine the presence of a proximity or touch event, or the output can be inputted into a discrete logic network to determine the presence of a proximity or touch event. 
       FIG. 3B  illustrates an exemplary touch sensor circuit  350  corresponding to a mutual-capacitance drive line  322  and sense line  326  and sensing circuit  314  according to examples of the disclosure. Drive line  322  can be stimulated by stimulation signal  306  (e.g., an AC voltage signal). Stimulation signal  306  can be capacitively coupled to sense line  326  through mutual capacitance  324  between drive line  322  and the sense line. When a finger or object  305  approaches the touch node created by the intersection of drive line  322  and sense line  326 , mutual capacitance  324  can be altered. This change in mutual capacitance  324  can be detected to indicate a touch or proximity event at the touch node, as described previously and below. The sense signal coupled onto sense line  326  can be received by sensing circuit  314 . Sensing circuit  314  can include operational amplifier  308  and at least one of a feedback resistor  312  and a feedback capacitor  310 .  FIG. 3B  illustrates a general case in which both resistive and capacitive feedback elements are utilized. The sense signal (referred to as Vin) can be inputted into the inverting input of operational amplifier  308 , and the non-inverting input of the operational amplifier can be coupled to a reference voltage V ref . Operational amplifier  308  can drive its output to voltage V o  to keep V in  substantially equal to V ref , and can therefore maintain V in  constant or virtually grounded. A person of skill in the art would understand that in this context, equal can include deviations of up to 15%. Therefore, the gain of sensing circuit  314  can be mostly a function of the ratio of mutual capacitance  324  and the feedback impedance, comprised of resistor  312  and/or capacitor  310 . The output of sensing circuit  314  Vo can be filtered and heterodyned or homodyned by being fed into multiplier  328 , where Vo can be multiplied with local oscillator  330  to produce V detect . V detect  can be inputted into filter  332 . One skilled in the art will recognize that the placement of filter  332  can be varied; thus, the filter can be placed after multiplier  328 , as illustrated, or two filters can be employed: one before the multiplier and one after the multiplier. In some examples, there can be no filter at all. The direct current (DC) portion of V detect  can be used to determine if a touch or proximity event has occurred. 
     Referring back to  FIG. 2 , in some examples, touch screen  220  can be an integrated touch screen in which touch sensing circuit elements of the touch sensing system can be integrated into the display pixel stackups of a display. The circuit elements in touch screen  220  can include, for example, elements that can exist in LCD or other displays (LED display, OLED display, etc.), such as one or more pixel transistors (e.g., thin film transistors (TFTs)), gate lines, data lines, pixel electrodes and common electrodes. In a given display pixel, a voltage between a pixel electrode and a common electrode can control a luminance of the display pixel. The voltage on the pixel electrode can be supplied by a data line through a pixel transistor, which can be controlled by a gate line. It is noted that circuit elements are not limited to whole circuit components, such as a whole capacitor, a whole transistor, etc., but can include portions of circuitry, such as only one of the two plates of a parallel plate capacitor. 
       FIG. 4A  illustrates a top view of an exemplary touch screen  400  including touch electrodes  404  and  406  arranged in rows and columns according to examples of the disclosure. Touch screen  400  can include a plurality of touch electrodes  404  configured as rows, and a plurality of touch electrodes  406  configured as columns. Touch electrodes  404  and/or touch electrodes  406  can include a transparent conductive material (e.g., ITO, AZO, indium-doped cadmium-oxide, or barium stannite). Touch electrodes  404  and touch electrodes  406  can be on the same or different material layers on touch screen  400  and can intersect with each other, as illustrated in  FIG. 4A . In some examples, touch screen  400  can sense the self-capacitance of touch electrodes  404  and  406  to detect touch and/or proximity activity on touch screen  400 . In some examples, touch screen  400  can sense the mutual capacitance between touch electrodes  404  and  406  to detect touch and/or proximity activity on touch screen  400 . 
       FIG. 4B  illustrates a top view of an exemplary touch screen  402  including touch electrodes  408  arranged in a pixelated touch electrode configuration according to examples of the disclosure. Touch screen  402  can include a plurality of touch electrodes  408  that can each identify or represent a unique location on the touch screen at which touch or proximity (i.e., a touch or proximity event) can be sensed. One or more touch electrodes can be electrically isolated from other touch electrodes in the touch screen, as previously described. In some examples, touch electrodes  408  can include a conductive material (e.g., ITO, AZO, indium-doped cadmium-oxide, or barium stannite). Touch electrodes  408  can be on the same or different material layers on touch screen  402 . In some examples, touch screen  402  can sense the self-capacitance of touch electrodes  408  to detect touch and/or proximity activity on touch screen  402 . In some examples, touch screen  402  can sense the mutual capacitance between touch electrodes  408  to detect touch and/or proximity activity on touch screen  402 . 
     Touch electrodes, such as touch electrodes  404  and  406  in  FIG. 4A  and touch electrodes  408  in  FIG. 4B , can be susceptible to external noise that can affect the sensitivity of the touch screen  400  or  402  detecting touch and/or proximity activity. Additionally, touch electrodes may be coupled to routing traces, which may be susceptible to external noise. Such external noise can originate from below the touch screen (for example, from a display in a touch screen) and/or from above the touch screen (for example, from capacitive coupling between a routing trace and the environment external to the touch sensor). Routing traces, for example, may be susceptible to capacitive coupling caused by contact between a touch object and the routing traces, which can manifest as a false touch reading (e.g., noise) detected at the touch electrode(s) corresponding to the routing trace. In some instances, it may be desirable to provide shielding from such noise sources above the touch screen (“top shielding”) and/or below the touch screen (“bottom shielding”). For example, noise sources above the touch screen can include noise sources above a cover material of a device including the touch screen and noise sources below the touch screen can include noise sources within the electronic device under (e.g., on a side of the touch screen opposite the cover material) the touch screen and/or noise sources external to the device proximate to an outer casing of the device. 
       FIG. 5A  illustrates a top view of an exemplary touch sensing layer included in a touch screen  500  according to examples of the disclosure. As shown in  FIG. 5A , in some examples, touch sensing layer of touch screen  500  can include a plurality of touch electrodes  502 - 510 . Touch electrodes  502 - 508  can be coupled to routing traces  522 - 528 , for example. Although touch electrodes  510  are not illustrated as being coupled to routing traces, it should be understood that in some examples, they may be. 
     Touch electrodes  502 - 510  and routing traces  522 - 528  can include a transparent conductive material, such as ITO, AZO, indium-doped cadmium-oxide, or barium stannite for example. In some examples, other materials are possible and touch electrodes  502 - 510  need not include the same material as routing traces  522 - 528 . Routing traces  522 - 528  can route one or more electrical signals indicative of the self-capacitance of the touch electrodes  502 - 508 , for example. In some examples, these signals can be received (e.g., by touch circuitry  300  or  350 ) to determine whether a touch object is proximate to or touching the touch screen  500 . 
       FIG. 5B  illustrates a top view of a section of an exemplary top shielding electrode  530  on top of a touch sensing layer included in a touch screen  500  according to examples of the disclosure. Touch screen  500  can include touch electrodes  502 - 510 , routing traces  522 - 524 , and top shielding electrode  530 . Touch electrodes  502  and  504  can be coupled to routing traces  522 - 524 , respectively. Although touch electrodes  510  are not illustrated as being coupled to routing traces, it should be understood that in some examples, they may be. Top shielding electrode  530  can be located on a layer on top (e.g., closer to a cover material such as cover material  890  illustrated in  FIG. 8 ) of touch electrodes  502 - 510  and routing traces  522 - 524 . In some examples, top shielding electrode  530  may be included in a layer (e.g., first electrode layer  910  illustrated in  FIGS. 9A-9B ) located between a cover material (e.g., cover material  890  illustrated in  FIG. 8 ) and the touch sensing layer (e.g., second electrode layer  920  illustrated in  FIGS. 9A-9B ). 
     In some examples, top shielding electrode  530  can include one or more openings  532  that overlap with at least portions of the touch electrodes  502 - 510 . The non-overlapping openings  532  can prevent or reduce any impact the top shielding electrode  530  may otherwise have on the capacitive coupling between a touch object and the top electrodes  502 - 510 . In the absence of such openings  532  (e.g., the top shielding electrode  530  includes material at locations that overlap with the touch electrodes), top shielding electrode  530  can reduce the sensitivity of touch electrodes  502 - 510 . In some examples, top shielding electrode  530  can include portions of material that overlap with routing traces  522 - 524 , thereby shielding routing traces  522 - 524  from noise sources that may cause unwanted capacitive coupling and/or inadvertent capacitive coupling to a touch object. In some instances, the touch electrodes  502 - 510  may not overlap with any portion of the top shielding electrode  530 , as illustrated in  FIG. 5B . Additionally or alternatively, the top shielding electrode  530  can fully or partially overlap routing traces  522 - 524 , as illustrated in  FIGS. 6B-6C  below. In some examples, openings  532  and/or touch electrodes  502 - 510  can be patterned into other shapes, such as rectangles, circles, diamonds, etc. 
     In some examples, as mentioned above, the touch screen  500  can further include a plurality of shielding layers. For example, the plurality of shielding layers can include a bottom shielding electrode (e.g., second shielding electrode  632  illustrated in  FIGS. 6B-6C ). The bottom shielding electrode may be placed beneath the top shielding electrode  530  (e.g., first shielding electrode  612  illustrated in  FIGS. 6B-6C ), the touch electrodes  502 - 510 , and the routing traces  522 - 524 . That is, the touch electrodes  502 - 510  and routing traces  522 - 524  can be located between a cover material and the bottom shielding electrode. 
     During operation, top shielding electrode  530  and the bottom shielding electrode can receive one or more voltage signals to mitigate unwanted capacitive coupling onto routing traces  522 - 524  and/or touch electrodes  502 - 510 , for example. In some examples, the one or more voltage signals can comprise the same voltage signal (e.g., from voltage source  306  illustrated in  FIGS. 3A-3B ) applied to the touch sensing circuitry (e.g., touch sensing circuitry  300  or  350  illustrated in  FIGS. 3A-3B ). In some instances, two or more of top shielding electrode  530 , the bottom shielding, one or more of the touch electrodes  502 - 510 , and the routing traces  522 - 524  can be electrically coupled together so that the coupled conductive elements can have the same electric potential. For example, one or more of touch electrodes  502 - 510  and the top shielding electrode  530  can be driven to the same electric potential by way of the coupled conductive elements. 
       FIG. 6A  illustrates top views of a plurality of electrode layers  610 ,  620 , and  630  included in an exemplary touch screen  600  according to examples of the disclosure. In some examples, touch screen  600  can include a first electrode layer  610 , a second electrode layer  620 , and a third electrode layer  630 . First electrode layer  610  can include a first shielding electrode  612  (e.g., top shielding electrode  530  illustrated in  FIG. 5B ). Second electrode layer  620  can include a plurality of touch electrodes  622  (e.g., touch electrodes  502 - 510  illustrated in  FIGS. 5A-B ) and one or more routing traces (e.g., routing traces  522 - 528  illustrated in  FIGS. 5A-B ). Third electrode layer  630  can include a second shielding electrode  632  (e.g., a bottom shielding electrode). In some examples, first electrode layer  610  can be patterned to include a plurality of openings  614  fully or partially overlap with touch electrodes  622  when the touch screen is assembled, as discussed above with reference to  FIGS. 5A-5B  and further with reference to  FIGS. 6B-6C  below. Electrode layers  610 ,  620 , and  630  are illustrated side-by-side here merely to show exemplary patterns of each layer. In some examples, the electrode layers  610 ,  620 , and  630  can be stacked to assemble touch screen  600 . 
     During operation, touch electrodes  622  can produce one or more touch signals, which can be transmitted to sense circuitry by way of a plurality of routing traces, as described above with reference to  FIGS. 2-4 , for example. In some examples, one or more touch electrodes  622  can be electrically coupled to the first shielding electrode  612  and/or the second shielding electrode  632 . The first shielding electrode  612 , second shielding electrode  632 , and one or more touch electrodes  622  (coupled to one or more of the shielding electrodes) can receive one or more AC or DC voltage signals, in some examples. The first shielding electrode  612  and second shielding electrode  632  can receive the same signal or different signals, for example. As described above with reference to  FIGS. 5A-5B , the AC or DC voltage signals applied to first shielding electrode  612  and second shielding electrode  632  can comprise one or more signals (e.g., from voltage source  306  illustrated in  FIGS. 3A-3B ) applied to touch sensing circuitry (e.g., touch sensing circuitry  300  or  350  illustrated in  FIGS. 3A-3B ), for example. In some examples, first electrode layer  610 , second electrode layer  620 , and third electrode layer  630  can be electrically coupled together using a plurality of vias, as will be described below. In this manner, the first shielding electrode  612 , the second shielding electrode  632 , and one or more touch electrodes  622  can receive the same signal. 
     Although first shielding electrode  612  is illustrated as having a grid shape with a plurality of openings  614 , in some examples, other shapes are possible. For example, first shielding electrode  612  can comprise a plurality of rectangular openings. Other shapes are possible. Although second electrode layer  620  is illustrated as including a plurality of touch electrodes  622  disposed in an array, in some examples, other electrode shapes are possible. For example, a plurality of row electrodes and a plurality of column electrodes on the same layer or different layers can be used. Although second shielding electrode  632  is illustrated as a continuous electrode on the third electrode layer  630 , in some examples, second shielding electrode  632  can be patterned. 
       FIGS. 6B-6C  illustrate cross-sectional views of the plurality of electrode layers  610 ,  620 , and  630  as arranged in an exemplary touch screen  600  according to examples of the disclosure. As illustrated in  FIG. 6B , in some examples, the first shielding electrode  612  and the plurality of touch electrodes  622  can be arranged in non-overlapping positions. For example, there can be non-overlapping sections  640  in the touch screen  600  where neither the first shielding electrode  612  nor the touch electrodes  622  may be located. Including non-overlapping sections  640  in touch screen  600  can reduce capacitive coupling between the first shielding electrode  612  and the touch electrodes  622 , for example. As illustrated in  FIG. 6C , in some examples, the first shielding electrode  612  and the plurality of touch electrodes  622  can be arranged in overlapping positions. For example, there can be overlapping sections  650  in the touch screen  600  where both the first shielding electrode  612  and the touch electrodes  622  may be located. In some examples, the overlapping section  650  can cause one or more touch electrodes  622  to capacitively couple to the first shielding electrode  612 . 
     In some examples, first electrode layer  610 , second electrode layer  620 , and third electrode layer  630  can be electrically coupled by one or more vias. The one or more vias can be placed in different locations of the device. For example, some of the vias can be placed in bond pad regions, and some of the vias can be placed in an edge region of the device. Exemplary placement of the vias will now be described with reference to  FIGS. 7A-7F . 
       FIGS. 7A and 7B  illustrate top views of an exemplary electronic device  701  including bond pad regions  750  and vias  780  and  770  according to examples of the disclosure. In some examples, electronic device  701  can further include a touch screen placed in inner region  703  similar to one or more touch screens described with reference to  FIGS. 1-6 . Inner region  703  can be fully or partially surrounded by an edge region  705  of the device  701 , for example. Electronic device  701  can include multiple bond pad regions  750 . The bond pad regions  750  can include one or more connectors (e.g., bond pads) that may electrically couple one or more routing traces (e.g., routing traces  522 - 528  illustrated in  FIGS. 5A-5B ) to off-panel circuitry (e.g., touch circuitry  300  or  350  illustrated in  FIGS. 3A and 3B , respectively). 
     As discussed above, the device can include multiple types of vias, such as shield-sensor vias and shield-shield vias. Shield-sensor vias can electrically couple one or more shielding layers to the touch sensing layer. Shield-shield vias can electrically couple multiple shielding layers together. Shield-sensor vias can be located in regions where a two-layer structure (described below) is located. For example, the bond pad regions  750  can include a two-layer structure, and shield-sensor vias  770  can be located in the bond pad regions  750 . Bond pad regions  750  can include a two-layer structure comprising two electrode layers (e.g., a top shielding layer such as first electrode layer  610  and a touch sensing layer such as second electrode layer  620 , as illustrated in  FIGS. 6A-C ). For example, one of the electrode layers (e.g., the touch sensing layer) can include one or more connective tabs located in the bond pad region  750  where shield-sensor vias  770  can be formed. 
     In some examples, electronic device  701  can further include shield-shield vias  780 , which can couple another pair of electrode layers (e.g., first electrode layer  610 , which can be a top shielding layer, and third electrode layer  630 , which can be a bottom shielding layer) of the electronic device. The shield-shield vias  780  can be placed in an edge region  705  (e.g., a border region) of the electronic device  701  with a first opaque mask  730  (illustrated in  FIGS. 7C and 7D ), for example. In some examples, first opaque mask  730  can include a plurality of notches  732  where the shield-shield vias  780  can be located. The shield-shield vias  780  can be located in the edge region  705  of the device while being electrically separated (e.g., maintaining a distance  781  away) from the first opaque mask  730 . In this way, although first opaque mask  730  can include a conductive material, first opaque mask  730  and shield-shield vias  780  can be electrically isolated. As shown in  FIGS. 7A-7B , the first electrode layer  707  can be located beneath the opaque mask  730  and can be exposed in the locations of the notches  732  in the opaque mask. In some embodiments, an insulating material is located between the first opaque mask  730  and the first electrode layer  707  to electrically isolate the first opaque mask  730  and the first electrode layer  707 . Placing shield-shield vias  780  in notches  732  of first opaque mask  730  can conserve space in the bond pad regions  750 , for example. Additionally or alternatively, placing shield-shield vias  780  in first opaque mask  730  can allow the electronic device  701  to be configured with smaller bond pad regions  750 . The top view illustrated in  FIGS. 7A-7B  includes the first electrode layer  707 , for example. It is understood that the third electrode layer overlaps with the first electrode layer  707  at locations of the vias  780  so that the vias  780  may provide an electrical connection between the first and third electrode layers. 
     Vias  780  can include endcaps  783  or  785 , for example. In some examples, as shown in  FIG. 7A , vias  780  can include circular endcaps  783 . Circular endcaps  783  can have a diameter that is substantially the same across all directions across the top of endcaps  783 . As shown in  FIG. 7B , in some examples, vias  780  can have oval endcaps  785  with an extended structure in one dimension. Also shown in  FIG. 7B , in some examples, the first electrode layer  707  can include tabs  708  that extend in an outward direction from vias  780 . The tabs  708  are extended portions of the first electrode layer  707  that extend from the rest of the edge of the first electrode layer  707 . It should be understood that, although not shown in  FIG. 7B , the third electrode layer can also include tabs that overlap the tabs  708  of the first electrode layer  707 . Other shapes and boundaries for the first electrode layer  707  and the third electrode layer that allow the first and third electrode layers to be connected by vias  780  are possible. Including one or more of oval endcaps  785  and electrode layer tabs  708  can, in some examples, increase the contact area of vias  780 , thereby lowering contact resistance and improving electrical characteristics. In some examples, discussed below with reference to  FIGS. 7C-7F , one or more routing traces  720  can be modified to maintain electrical isolation from vias  780 . 
       FIGS. 7C and 7D  illustrate top views of exemplary touch screen  700  including routing traces  720  having diverted portions  723  attached to first sections  722  of the routing traces according to examples of the disclosure. In some examples, touch screen  700  can include a supporting substrate  790 , plurality of touch electrodes  710  included in the second electrode layer, routing traces  720  included in the second electrode layer, shield-sensor vias  770  that couple the second electrode layer to one of the first electrode layer and the third electrode layer, shield-shield vias  780  that couple the first electrode layer  707  to the third electrode layer, first opaque mask  730  located on top of the first electrode layer, and second opaque mask  740  located on top of the first opaque mask. Although the first electrode layer  707  is illustrated in  FIGS. 7C and 7D  for ease of illustration, it should be understood that, in some examples, the first electrode layer  707  includes patterning, such as the patterning described above with reference to  FIG. 6A . 
     As shown in  FIG. 7C , in some examples vias  780  can include circular endcaps  783 . As shown in  FIG. 7D , in some examples vias  780  can include oval endcaps  783  and the first electrode layer  707  can include tabs  708  at locations corresponding to notches  732  of the first opaque black mask  730 . It is understood that although the third electrode layer is not illustrated in  FIG. 7D , the third electrode layer can also include tabs at the locations of the tabs  708  of the first electrode layer  707 . 
     Routing traces  720  can be coupled to pixelated touch electrodes  710  to form connections in the bond pad region  750  to touch circuitry (e.g., touch circuitry  300  or  350 ) or other circuitry. Routing traces  720  can include first conductive segments  722  and second conductive segments  724 . In some examples, first conductive segments  722  can include a transparent conductive material such as ITO, AZO, indium-doped cadmium-oxide, barium stannite or another transparent conductive material. Second conductive segments  724  can include a metallic conductive material such as copper, gold, or another opaque conductive material. In some examples, second conductive segments  724  can include a transparent conductive material that is the same as or different from a material included in first conductive segments  722 . In some examples, first conductive segments  722  can have a lower electrical conductivity than second conductive segments  724 . 
     Some of the routing traces  720  can include diverted portions  723 . As illustrated in  FIGS. 7C and 7D , the one or more diverted portions  723  can be coupled between the first conductive segments  722  and the second conductive segments  724  of routing traces  720 , for example. In some examples, diverted portions  723  can include a same material included in first conductive segments  722 . In some examples, the diverted portions  723  of the routing traces can be placed and shaped to avoid the shield-shield vias  780 . If, for example, rather than including the diverted portions  723  illustrated in  FIGS. 7C-7D , the first conductive segments  722  of the routing traces  720  extended to the locations of the second conductive segments  724  of the routing traces, the routing traces  722  could overlap the shield-shield vias  780 . Because the routing traces  720  are located on the second electrode layer which is between the first electrode layer  707  and the third electrode layer, overlapping the routing traces with the shield-shield vias  780  could cause the routing traces to be coupled to the first electrode layer  707  and the second electrode layer. Thus, the diverted portions  723  of the routing traces  720  can be included to allow the routing traces to avoid the shield-shield vias  780 . 
       FIGS. 7E and 7F  illustrate top views of exemplary touch screen  700  including a plurality of routing traces  720  having diverted portions  723  attached to third sections  725  of the routing traces according to examples of the disclosure. Although the first electrode layer  707  is illustrated in  FIGS. 7E and 7F  for ease of illustration, it should be understood that, in some examples, the first electrode layer  707  includes patterning, such as the patterning described above with reference to  FIG. 6A . 
     In some examples, the third sections  725  of the routing traces  720  can include the same material (e.g., an opaque conductive material such as copper or gold or a transparent conductive material such as ITO, AZO, indium-doped cadmium-oxide, or barium stannite) as included in the second sections  724  of the routing traces. Some of the routing traces  720  can include diverted portions  723 , as will be described below. In some examples, the first conductive segments  722  and diverted portions  723  of the routing traces  720  can have a lower electrical conductivity than the second conductive segments  724  and the third conductive segments  725 . As illustrated in  FIGS. 7E and 7F , in some examples, one or more routing traces  720  including diverted portions  723  can further include third conductive segments  725  between first conductive segments  722  and the diverted portions  723 . The diverted portions  723  can connect the third conductive segments  725  to the second conductive segments  724 , for example. In some examples, the third conductive segments  725  can include the same material included in second conductive segments  724 . Further, in some examples, the diverted portions  723  can include the same material included in first conductive segments  722 . As described above with reference to  FIGS. 7C and 7D , the diverted portions  723  of the routing traces  720  allow the routing traces to avoid overlapping and, thus, making electrical contact with, the shield-shield vias  780 . 
     The touch screen  700  can include an inner region (e.g., active area and/or display area) including the touch electrodes  710  and the first conductive portions  722  of the routing traces  720 . In some examples, the inner region can further include display pixels for displaying an image on touch screen  700 . The first conductive portions  722  of the routing traces  720  can be transparent to reduce visual artifacts on a display included in the inner region of the touch screen  700 , for example. In some examples, the outer region (e.g., edge region) that includes the first opaque mask  730 , the second opaque mask  740 , shield-sensor vias  770 , and shield-shield vias  780  can fully or partially be located around (e.g., surround) the inner region. Thus, the touch screen  700  can include an inner region that includes touch electrodes  710  and display pixels and an outer region that is not part of the display and is covered by one or more opaque masks. 
     As shown in  FIG. 7E , in some examples vias  780  can include circular endcaps  783 . As shown in  FIG. 7F , in some examples vias  780  can include oval endcaps  783  and the first electrode layer  707  can include tabs  708  at locations corresponding to notches  732  of the first opaque black mask  730 . Although not shown in  FIG. 7F , in some embodiments the third electrode layer includes tabs at the locations of the tabs  708  of the first electrode layer  707 . Touch screen  700  can further include a bond pad region  750  where a plurality of routing traces  720  can be located to form connections to touch circuitry (e.g., touch circuitry  300  or  350 ) or to other circuitry. Additionally, in some examples, the shield-sensor vias  770  can be located in the bond pad region  750 . 
     Although not illustrated in the figures, examples of the disclosure can include the routing traces having a first material in the inner region and a second material in the outer region. For example, the routing traces can include a transparent conductive material in the inner region and a metallic conductive material in the outer region. The different materials can connect at the location of the touch sensing layer where the first opaque mask  730  or the second opaque mask  740  overlaps. 
     In some examples, the shield-sensor vias  770  can couple the first electrode layer  707  (e.g., first electrode layer  610 , which can be a top shielding layer) including a first shielding electrode (e.g., top shielding electrode  612 , which can be a patterned shielding electrode) to a second electrode layer (e.g., second electrode layer  620 , which can be a touch sensing layer) including the touch electrodes  710  (e.g., touch electrodes  408 ,  502 - 510 , or  622 ) and routing traces  720 . Shield-sensor vias  770  can be placed in the bond pad region  750  proximate to, but not overlapping, routing traces  720 , for example. In some examples, the second electrode layer can include one or more tabs placed in the bond pad region  750  through which vias  770  can be formed. 
     In some examples, the shield-shield vias  780  can couple the first electrode layer (e.g., first electrode layer  610  illustrated in  FIGS. 6A-C ) including a first shielding electrode (e.g., first shielding electrode  612 , which can be a top shielding electrode) to a third electrode layer (e.g., third electrode layer  630 , which can be a bottom shielding layer) including a second shielding electrode (e.g., second shielding electrode  630 , which can be a bottom shielding electrode). The shield-shield vias  780  can be located in the edge region of the touch screen away from bond pad region  750 . In some examples, the first opaque mask  730  can include a non-metallic conductive material and can include a plurality of notches  732  to accommodate the shield-shield vias  780  so that the shield-shield vias  780  do not contact the first opaque mask. 
     By coupling the first and second electrode layers using the shield-sensor vias  770  and coupling the first and third electrode layer using the shield-shield vias  780 , the first, second, and third electrode layers can all be coupled together. In some examples, spacing between the shield-sensor vias  770  and the shield-shield vias  780  can be based on a targeted electrical performance of the touch screen  700 . For example, the shield-sensor vias  770  and the shield-shield vias  780  can be placed close to each other on the touch screen  700  to reduce the electrical resistance of the conductive pathway between the vias. In some examples, the shield-shield vias  780  can also be placed such that they are away from the bond pad region  750  to conserve space within the bond pad region  750 . Further, shield-shield vias  780  can be placed at least a threshold distance away from the routing traces  720  to reduce or eliminate capacitive coupling between the shield-shield vias and the routing traces, for example. In some examples, the shield-shield vias  780  can be placed in parts of the outer region with as few routing traces  720  as possible. That is, certain regions of the outer region may have different densities of routing traces  720 . In some examples, shield-shield vias  780  can be placed in a part of the outer region having a lower density of routing traces (e.g., further from the bond pad region  750 ) than another part of the outer region (e.g., closer the bond pad region  750 ). Although  FIGS. 7A-C  illustrate shield-shield vias  780  as being located near corners on a bond pad side  750  of the touch screen  700 , in some examples, shield-shield vias  780  can be located along an edge of the device. For example, shield-shield vias  780  can be placed along the side opposite the bond pads  750  to avoid routing traces  720  or along the bond pad side to be closer to shield-sensor vias  770  to reduce electrical resistance between the types of vias. Other locations for shield-shield vias  780  can be selected based on electrical resistance between the types of vias and/or the density of the routing traces  720  at various locations on the touch screen  700 . 
     One or more routing traces can comprise one or more diverted portions  723 . In some examples, the diverted portions  723  can include a transparent conductive material (e.g., ITO, AZO, indium-doped cadmium-oxide, or barium stannite). Adding the diverted portions  723  can make the routing traces  720  longer than a distance between the respective touch electrode  710  and the shield-shield vias  780 , but can ensure that each routing trace maintains the threshold distance away from the shield-shield vias. 
     Although a number of touch electrodes  710  illustrated in  FIGS. 7B-7C  are shown without being coupled to routing traces, it should be understood that, in some examples, they may well be. Further, although routing traces  720  are illustrated as being connected to touch electrodes  710  by portions having substantially the same width as the touch electrodes, in some examples, the routing traces can have a narrower width where connected with the touch electrodes. For example, the first sections  722  of the routing traces  720  can have a width that is narrower than the touch electrodes  710 . In some examples, touch screen  700  can include touch electrodes having a different pattern than illustrated in  FIGS. 7B-7C , such as touch electrodes arranged in rows and columns (e.g., row and column touch electrodes as illustrated in  FIG. 4A ). 
     As discussed above, in some examples, the shield-shield vias  780  and metal portions  724  of the routing traces  720  can be concealed by a second opaque mask  740 . The second opaque mask  740  can be positioned such that it overlaps at least a portion of first opaque mask  730 . In some examples, the second opaque mask  740  can surround the outer edge of the first opaque mask  730 . The first opaque mask  730  can extend inward from the inner edge of second opaque mask  740 . The alignment of first opaque mask  730  and second opaque mask  740  will be described in further detail with reference to  FIG. 8 . 
       FIG. 8  illustrates a cross-sectional view of exemplary touch screen  800  including a cover material  890 , a first opaque mask  830 , and a second opaque mask  840  according to examples of the disclosure. In some examples, touch screen  800  can include one or more components of touch screen  600  or  700 . Touch screen  800  can further include first opaque mask  830 , second opaque mask  840 , substrate  880 , and cover material  890 . In some examples, first opaque mask  830  can be formed on substrate  880 , and second opaque mask  840  can be formed on an underside (e.g., a side internal to the electronic device) of cover material  890 . In some examples, first opaque mask  830  can be located closer to the touch sensing layer than the second opaque mask  840 . As described above with reference to  FIGS. 7A-7F , first opaque mask  830  and second opaque mask  840  can both be located (i.e., overlap) in overlapping section  835 . In some examples, one or more vias (e.g., shield-shield vias  780 ) can be placed within overlapping section  835 . In this way, notches (e.g., notches  732 ) can be formed in first opaque mask  830  to accommodate the vias, and the vias can still be concealed by second opaque mask  840 . In some examples, substrate  880  can be a transparent insulating material layer that provides structural support to one or more material layers placed on the substrate (e.g., one or more electrode layers or other components). In some examples, such as in examples where the first opaque mask  830  includes an insulating material, one or more of the electrode layers can be located between the opaque mask and substrate  880 . Further, in some examples, substrate  880  can include one or more substrates joined together by one or more adhesives (not shown). 
     In some examples, touch screen  800  can include one or more electrode layers electrically coupled by one or more vias. The structure of the vias will now be described with reference to  FIGS. 9A-9D . 
       FIGS. 9A-9D  illustrate cross-sectional views of exemplary touch screen  900  according to example of the disclosure. In some examples, touch screen  900  can include first electrode layer  910 , second electrode layer  920 , and third electrode layer  930 . First electrode layer  910  can include a first shielding electrode (e.g., top shielding electrode  612 ), second electrode layer  920  can include a plurality of touch electrodes (e.g., touch electrodes  510 ,  622 , or  710 ), and third electrode layer  930  can include a second shielding electrode (e.g., bottom shielding electrode  632 ). In some examples, shield-shield via  980  can optionally include a conductive portion  925  that contacts the second electrode layer  920 . Touch screen  900  can further include a first substrate  950 , second substrate  960 , shield-sensor via  970 , and shield-shield via  980 . Shield-sensor via  970  can include endcaps  972  or  994  and middle section  974 . Shield-shield via  980  can include endcaps  982  or  992  and middle section  984 . 
     Although  FIGS. 9A-9D  illustrate cross-sectional views of touch screen  900 , it should be noted that the top view structure of via endcaps  972 ,  982 ,  992 , and  994  can vary. For example, endcaps  972  and  982  can be circular endcaps (e.g., as illustrated in  FIGS. 7A, 7C, and 7E  above) and endcaps  992  and  994  can be oval endcaps with extended structure in one dimension (e.g., as illustrated in  FIGS. 7B, 7D, and 7F  above).  FIGS. 7B, 7D, and 7F  illustrate a cross-section of touch screen  900  across the dimension in which oval endcaps  992  and  994  are extended, for example. Although  FIGS. 7B, 7D, and 7F  illustrate endcaps  992  and  994  as being extended in the same dimension, in some examples, one or more endcaps  992  and/or  994  can be extended in different dimensions. In some examples, vias  970  and  980  can include oval endcaps  992  and  994  on both sides, as illustrated in  FIGS. 9C and 9D . In some examples, vias  970  and  980  can include oval endcaps  992  and  994  on one side and circular endcaps  972  and  982  on another side. 
     In some examples, shield-sensor via  970  can be placed in an overhanging portion  952  of the touch screen  700 , where part of first electrode layer  910  and second electrode layer  920  can extend past the third electrode layer  930 . For example, overhanging portion  952  can be placed in a bond pad region (e.g., bond pad region  750 ) of the electronic device. In some examples, shield-sensor via  970  can include a conductive paste and can thereby form an electrical connection between first electrode layer  910  and second electrode layer  920 . In some examples, endcaps  972  or  994  can form connections to the first electrode layer  910  and the second electrode layer  920 . The endcaps  972  or  994  can be electrically coupled to each other by way of middle portion  974 , which can be placed within a hole drilled through first electrode layer  910 , second electrode layer  920 , and first substrate  950  after the touch screen  900  is assembled, for example. In this way, the first electrode layer  910  and the second electrode layer  920  can be electrically coupled, for example. 
     In some examples, the first electrode layer  910 , second electrode layer  920 , and first substrate  950  can include holes before the touch screen  900  is assembled. The holes can be aligned and filled with the conductive material to form via  970 . In some examples, the endcaps  972  or  994  of shield-sensor via  970  can include any conductive structure that creates an electrical pathway between the respective first electrode layer  910  or second electrode layer  920  and the middle portion  974  of the shield-sensor via  970 . Examples of the disclosure can include endcaps  972  or  994  having a different shape (e.g., different than cap-shaped) than illustrated in the figures. 
     Shield-shield via  980  can be placed in an overlapping portion  962  of the touch screen  900  where parts of the first electrode layer  910 , the second electrode layer  920 , and the third electrode layer  930 , may be located (e.g., overlap) for example. In some examples, the overlapping portion  964  of touch screen  900  can be placed in an edge region of an electronic device (e.g., as illustrated in  FIGS. 7A-7F ). Shield-shield via  980  can include a conductive paste and can thereby form an electrical connection between first electrode layer  910  and third electrode layer  930 , for example. In some examples, endcaps  982  or  992  can form connections to the first electrode layer  910  and the third electrode layer  930 . The endcaps  982  or  992  can be electrically coupled by way of middle portion  984 , which can be placed within a hole drilled through first electrode layer  910 , second electrode layer  920 , third electrode layer  930 , substrate  960 , adhesive  940 , and first substrate  950  after touch screen  900  is assembled, for example. In this way, first electrode layer  910  and third electrode layer  930  can be electrically coupled. In some examples, the first electrode layer  910 , second electrode layer  920 , third electrode layer  930 , second substrate  960 , adhesive  940 , and first substrate  950  can be include holes before the touch screen  900  is assembled. The holes can be aligned and filled with the conductive material to form via  980 . In some examples, the endcaps  982  or  992  of shield-shield via  980  can include any conductive structure that creates an electrical pathway between the respective first electrode layer  910  or third electrode layer  930  and the middle portion  984  of the shield-shield via. That is to say, the endcaps  982  or  992  need not be cap-shaped, although in some examples they may be. 
     In some examples, the shield-shield via can optionally include a conductive portion  925  that electrically contacts the second electrode layer  920 , thereby coupling the first electrode layer  910 , the second electrode layer  920 , and the third electrode layer  930  together. In some examples, conductive portion  925  can be omitted. Although conductive portion  925  is illustrated as being on a top side of the second electrode layer  920 , in some examples, the conductive portion can have a different location (e.g., on a bottom side of or embedded in the second electrode layer). 
     As illustrated in  FIGS. 9B and 9D , in some examples, the first substrate  960  and the second electrode layer  920  can be joined by adhesive  940 . Overhanging portion  954  can include part of the second electrode layer  920  and part of the third electrode layer  930 , for example. The overhanging portion  954  can be placed in a bond pad region (e.g., bond pad region  950 ) of the device including touch screen  900 . Shield-sensor via  970  can include a conductive paste and can thereby form an electrical connection between third electrode layer  930  and second electrode layer  920 , for example. In some examples, endcaps  972  or  994  can form connections to the third electrode layer  930  and the second electrode layer  920 . The endcaps  972  or  994  can be electrically coupled by way of middle portion  974 , which can be placed within a hole drilled (e.g., using laser ablation) through third electrode layer  930 , second electrode layer  920 , and substrate  950  after touch screen  900  is assembled, for example. In this way, second electrode layer  920  and third electrode layer  930  can be electrically coupled. In some examples, the third electrode layer  930 , second electrode layer  920 , and substrate  950  can include holes before touch screen  900  is assembled. The holes can be aligned and filled with the conductive material to form shield-sensor via  970 . In some examples, the endcaps  972  or  994  of shield-sensor via  970  can include any conductive structure that creates an electrical pathway between the second electrode layer  920  or third electrode layer  930  and the middle portion  974 . Examples of the disclosure can include the endcaps  972  or  994  as having shapes different (e.g., different than cap-shaped) than illustrated in the figures. 
     Shield-shield via  980  can be placed in an overlapping portion  964  of touch screen  900  where the first electrode layer  910 , the second electrode layer  920 , and the third electrode layer  930  can be located (e.g., overlap). In some examples, overhanging portion  964  can be placed in an edge region of an electronic device including touch screen  900 , as illustrated above in  FIGS. 7A-7F . Shield-shield via  980  can include a conductive paste and can thereby form an electrical connection between first electrode layer  910  and third electrode layer  930 , for example. In some examples, endcaps  982  or  992  can form connections to the first electrode layer  910  and the third electrode layer  930 . The endcaps  982  or  992  can be electrically coupled to each other by way of middle portion  984 , which can be placed within a hole drilled through first electrode layer  910 , second electrode layer  920 , third electrode layer  930 , substrate  960 , adhesive  940 , and substrate  950  after touch screen  900  is assembled, for example. In this way, the first electrode layer  910  and the third electrode layer  930  can be electrically coupled. In some examples, the first electrode layer  910 , second electrode layer  920 , third electrode layer  930 , substrate  960 , adhesive  940 , and substrate  950  can include holes before touch screen  900  is assembled. The holes can be aligned and filled with the conductive material to form via  980 . In some examples, the endcaps  982  or  992  of shield-shield via  980  can include any conductive structure that creates an electrical pathway between the respective first electrode layer  910  or third electrode layer  930  and the middle portion  984  of the shield-shield via. That is to say, the endcaps  982  or  992  need not be cap-shaped, although in some examples they may be. In some examples, shield-shield via  980  can include a conductive portion  925  that electrically contacts second electrode layer  920 , thereby coupling the first electrode layer  910 , the second electrode layer  920 , and the third electrode layer  930 . In some examples, conductive portion  925  can be omitted. Although conductive portion  925  is illustrated as being on a top side of the second electrode layer  920 , in some examples, conductive portion can have a different location (e.g., on a bottom side of or embedded in the second electrode layer  920 ). 
     Although touch screen  900  is illustrated as including first electrode layer  910 , second electrode layer  920 , third electrode layer  930 , first substrate  950 , second substrate  960 , shield-sensor via  970 , and shield-shield via  980 , in some examples, additional or alternative components are possible. For example, touch screen  900  can include additional adhesives, substrates, passivation layers, and/or conformal layers not shown here. In some examples, substrates  950  and  960  (and any additional substrates not shown here) can include materials (e.g., insulating and/or transparent materials) that provide structural support to one or more additional materials placed on the substrate (e.g., one or more electrode layers or other components). For example, although  FIGS. 9A and 9C  illustrate the second electrode layer  920  and the second substrate  960  as being joined by an adhesive  940 , in some examples, additional or alternative adhesive layers can be used. Likewise, although  FIGS. 9B and 9D  illustrates the second substrate  960  as being joined to the second electrode layer  920  by adhesive  940 , in some example, alternative arrangements are possible. For example, one or more of the first substrate  950  and the second substrate  960  can include multiple substrates (e.g., supportive, transparent, and/or insulating layers) joined by one or more adhesives. In some examples, touch screen  900  may not include an adhesive  940  between the second electrode layer  920  and the second substrate  960 . Further, in some examples, touch screen  900  can include additional electrode layers (e.g., to accommodate row and column touch electrodes as illustrated in  FIG. 4A ). In some examples, one or more components of touch screen  900  may be eliminated or replaced. 
       FIGS. 10A-10F  illustrate cross-sectional views of an exemplary touch screen  1000  during a manufacturing process according to examples of the disclosure. In some examples, touch screen  1000  can include some or all of the same components included in touch screen  900  as illustrated in  FIGS. 9A and 9C . It should be understood that the touch screen  900  illustrated in  FIGS. 9B and 9D  can be manufactured in a similar manner to touch screen  1000 , although the arrangement of some components may differ, resulting in some deviations in manufacturing. 
       FIG. 10A  illustrates exemplary touch screen  1000  during a first stage of manufacturing according to examples of the disclosure. Touch screen  1000  can include a two-layer structure  1055  formed on a first substrate  1050  and a one-layer structure  1065  formed on a second substrate  1060 . Two-layer structure can include first electrode layer  1010  (e.g., a top shielding layer), first substrate  1050 , and second electrode layer  1020  (e.g., a touch sensing layer). One-layer structure  1065  can include second substrate  1060  and third electrode layer  1030  (e.g., a bottom shielding layer). Substrates  1050  and/or  1060  can include a material (e.g., a transparent and/or insulating material) to provide structural support to one or more layers or materials on the substrate (e.g., one or more electrode layers or other components), for example. In some examples, substrates  1050  and/or  1060  can include multiple substrate layers joined by adhesive(s). First electrode layer  1010  can include a top shielding electrode, which can be a patterned shielding electrode (e.g., top shielding electrode  612 ). Second electrode layer  1020  can include a plurality of touch electrodes. Third electrode layer can include one or more second shielding electrodes. In some examples, first electrode layer  1010  and second electrode layer  1020  can include one or more electrodes including ITO and two-layer structure can be a DITO layer. Likewise, in some examples, third electrode layer  1030  can include one or more electrodes including ITO, and one-layer structure  1065  can be a SITO layer. In some examples, first electrode layer  1010 , second electrode layer  1020 , and third electrode layer  1030  can include electrodes including another transparent, semi-transparent, or opaque conductive material. During a first stage of manufacture, the two-layer structure  1055  and one layer structure  1065  are provided for use in the subsequent manufacturing steps. 
       FIG. 10B  illustrates exemplary touch screen  1000  at a second stage of manufacturing according to examples of the disclosure. Two-layer structure  1055  and one layer structure  1065  can be joined using adhesive  1040  (e.g., during a lamination process), for example. The section of touch screen  1000  where two-layer structure  1055  and one-layer structure  1065  are joined can be an overlapping section  1062  of the touch screen. In some examples, the two-layer structure  1055  can include an overhanging section  1052  that extends beyond the one-layer structure  1065 . In some examples, the overhanging section  1052  can be placed in a bond pad region of the touch screen  1000  (e.g., bond pad region(s)  750  of touch screen  700  illustrated in  FIGS. 7A-F ). 
       FIG. 10C  illustrates exemplary touch screen  1000  at a third stage of manufacturing according to examples of the disclosure. During the third stage of manufacturing, a first hole  1076  can be drilled through the two-layer structure  1055  at a position in the overhanging section  1052  of touch screen  1000 , and a second hole  1086  can be drilled through both the two-layer structure  1055  and the one layer structure  1065  in the overlapping section  1062  of touch screen  1000 . In some examples, the first hole  1076  and the second hole  1086  can be formed using laser ablation. For example, a ring-shaped cut can be made through touch screen  1000 , causing a truncated cone-shaped peg to be formed. The peg can be ejected (e.g., using air) from the hole afterwards, for example, leaving behind hole  1076  or  1086 . In some examples, the holes  1076  and  1086  can be formed by first drilling a small hole, then gradually increasing the size of the hole. Regardless of which drilling technique is used, several characteristics of the laser can be controlled to ensure a clean cut without damaging any of the layers of touch screen  1000 . For example, the temperature can be controlled to avoid melting adhesive  1040  or any other component of touch screen  1000 . In some examples, holes  1076  and  1086  can be formed using alternative methods other than laser ablation. In some examples, two-layer structure  1055  and one-layer structure  1065  can be formed with holes, and the holes can be aligned when the structures are adhered. 
       FIG. 10D  illustrates exemplary touch screen  1000  at a fourth stage of manufacturing according to examples of the disclosure. During the fourth stage of manufacturing, the first hole  1076  and second hole  1086  can be filled with a conductive paste to begin to form two conductive vias. A middle section  1074  of a shield-sensor via can be formed in the first hole positioned in the overhanging section  1052  of the touch screen  1000 . Likewise, a middle section  1084  of a shield-shield via can be formed in the second hole positioned in the overlapping section  1062  of the touch screen  1000 . In some examples, the conductive paste can be filled from one side of the touch screen  1000  (e.g., from the side having first electrode layer  1010  or from the side having second electrode layer  1020  and third electrode layer  1030 ). In some examples, the conductive paste can be filled from both sides of the touch screen  1000  simultaneously or sequentially. 
       FIGS. 10E and 10F  illustrate exemplary touch screen  1000  at a fifth stage of manufacturing according to examples of the disclosure. During the fifth stage of manufacturing, endcaps  1072  or  1094  of shield-sensor via  1070  and endcaps  1082  or  1092  of shield-shield via  1080  can be formed. In some examples, endcaps  1072 , 1082 ,  1092 , and  1094  can be formed while middle sections  1074  and  1084  are being formed. For example, one or more holes (e.g., holes  1076  and/or  1086 ) can be overfilled with conductive paste so that the middle portions  1074  and  1084  overfill to form endcaps  1072 , 1082 ,  1092 , and  1094 . Endcaps  1072  and  1094  of shield-sensor via  1070  can form electrical connections to first electrode layer  1010  and second electrode layer  1020 . Likewise, endcaps  1082  and  1092  of shield-shield via  1080  can form electrical connections to first electrode layer  1010  and third electrode layer  1082 . By positioning the shield-sensor via  1070  in the overhanging section  1052  of touch screen  1000 , a surface of second electrode layer  1020  may be exposed, allowing an endcap  1072  or  1094  to be formed in contact with the second electrode layer  1020 . Endcaps  1072 , 1082 ,  1092 , and  1094  can be formed when the holes (e.g., holes  1076  and  1086 ) are filled from one side of touch screen  1000  or when the holes are filled from both sides of the touch screen sequentially or simultaneously. In some examples, endcaps  1072 , 1082 ,  1092 , and  1094  can include any electrical structure that forms an electrical connection between the respective electrode layer to make contact with the center portion (e.g., center portion  1074  or  1084 ) of the respective via of the endcap. That is to say, endcaps  1072 , 1082 ,  1092 , and  1094  need not be cap-shaped, though in some examples they may be. 
     Although  FIGS. 10E and 10F  illustrate cross-sectional views of touch screen  1000 , it should be noted that the top view structure of via endcaps  1072 ,  1082 ,  1092 , and  1094  can vary. For example, endcaps  1072  and  1082  can be circular endcaps (e.g., as illustrated in  FIGS. 7A, 7C , and  7 E above) and endcaps  1092  and  1094  can be oval endcaps with extended structure in one dimension (e.g., as illustrated in  FIGS. 7B, 7D, and 7F ).  FIGS. 7B, 7D, and 7F  illustrate a cross-section of touch screen  1000  across the dimension in which oval endcaps  1092  and  1094  are extended, for example. Although  FIGS. 7B, 7D, and 7F  illustrate endcaps  1092  and  1094  as being extended in the same dimension, in some examples, one or more endcaps  1092  and/or  1094  can be extended in different dimensions. In some examples, vias  1070  and  1080  can include oval endcaps  1092  and  1094  on both sides, as illustrated in  FIG. 10F  (e.g., the fifth step in the manufacturing process can be performed as illustrated in  FIG. 10F ). In some examples, vias  1070  and  1080  can include oval endcaps  1092  and  1094  on one side and circular endcaps  1072  and  1082  on another side (e.g., the fifth step in the manufacturing process can be performed in some ways as illustrated in  FIG. 10E  and in some ways as illustrated in  FIG. 10F ). In some examples, vias  1070  and  1080  can include circular endcaps  1072  and  1082  on both sides (e.g., the fifth step in the manufacturing process can be performed as illustrated in  FIG. 10E ). 
     Although specific stages of manufacturing have been described with reference to  FIGS. 10A-10F , it should be understood that in some examples, additional or alternative stages of manufacturing can be used. Further, the aforementioned stages can be performed in an order different from the order in which the stages are described. For example, shield-sensor via  1070  can be formed on two-layer structure  1055  before the two-layer structure and the one-layer structure  1065  are joined by adhesive  1040 . Other modifications to the manufacturing process are possible. Further, touch screen  1000  can include additional components to those described here. For example, one or more passivation layers and/or additional substrates can be added to touch screen  1000 . In some examples, touch screen  1000  can include one or more additional electrode layers (e.g., to accommodate row and column touch electrodes, such as those illustrated in  FIG. 4A ). Other additional components are possible. 
       FIG. 11  illustrates an exemplary process flow  1100  for forming a touch screen according to examples of the disclosure. At step  1102 , a two-layer structure (e.g., two-layer structure  1055 ) can be formed. At step  1104 , a one-layer structure (e.g., one-layer structure  1065 ) can be formed. Steps  1102  and  1104  can correspond to  FIG. 10A  described above. At step  1106 , the two-layer structure and one-layer structure can be joined together using, for example, an adhesive (e.g., adhesive  940  or  1040 ), as illustrated in  FIG. 10B  above. At step  1108 , holes (e.g.,  1076  and  1086 ) can be drilled through the touch screen (e.g., touch screen  1000 ) for vias (e.g., vias  970 ,  980 ,  1070 , and/or  1080 ), as described above with reference to  FIG. 10C . At step  1110 , the vias can be filled as described above with reference to  FIG. 10D . At step  1112 , the via endcaps (e.g., endcaps  972 ,  982 ,  1072 , and/or  1082 ) can be formed, as illustrated in  FIG. 10E . In some examples, additional or alternative steps are possible. Further, although steps  1102 - 1112  have been described in a particular order, in some examples, the steps can be performed in different orders and/or two or more steps may be performed concurrently. In some examples, the touch screen can further include one or more passivation or conformal layers, as will be described below with reference to  FIGS. 12-13 . 
       FIGS. 12A and 12B  illustrate cross-sectional views of a portion of an exemplary touch screen  1200  including passivation layers  1202  and  1204  and a via  1270  between electrode layers  1210  and  1220  according to examples of the disclosure. Touch screen  1200  can include a first electrode layer  1210  (e.g., a top shielding layer), a second electrode layer  1220  (e.g., a touch sensing layer), substrate  1250 , via  1270 , first passivation layer  1202 , second passivation layer  1204 , and conformal layer  1206 . Via  1270  can include endcaps  1272  or  1294  and center portion  1274 , for example. In some examples, endcaps  1272  or  1294  can form electrical connections to the first electrode layer  1210  and the second electrode layer  1220  and can be electrically coupled by center portion  1274 . 
     In some examples, when a hole is drilled through touch screen  1200  during manufacture, the hole can be wider at the first passivation layer  1202  than it is at the first electrode layer  1210 , thereby exposing part of the first electrode layer  1210  so that it can contact an endcap  1272  of via  1270 . As shown in  FIG. 12A , one of the endcaps  1272  of via  1270  completely covers the exposed portion of the first electrode layer  1210  that does not overlap with the first passivation layer  1202 . Accordingly, the first electrode layer  1210  can be completely covered by first passivation layer  1202  and an endcap  1272  of via  1270 , thereby protecting the first electrode layer from corrosion, for example. In some examples, via  1270  and/or first passivation layer  1202  can include corrosion-resistant materials to protect touch screen  1200 . 
     In some examples, the hole can be even wider across second passivation layer  1204  than it is across first passivation layer  1202 , as shown in  FIG. 12A . Part of an exposed portion of the second electrode layer  1220  can contact an endcap  1272  of via  1270  to form an electrical connection. In some examples, there can be an exposed portion of the second electrode layer  1220  that lies between the endcap  1272  of via  1270  and the second passivation layer  1204 . To protect this exposed portion of the second electrode layer  1220 , an additional conformal layer  1206  can be placed on top of the second electrode layer  1220 , the endcap  1272  of via  1270 , and the second passivation layer  1204  to completely cover the second electrode layer  1220  and protect the touch screen  1200  from corrosion. 
     As shown in  FIG. 12B , both of first electrode layer  1210  and second electrode layer  1220  can be protected entirely by the endcaps  1272  and  1294  of via  1270  in some example. For example, endcap  1294  can be an oval endcap with an extended structure in one dimension (e.g., as illustrated in  FIGS. 7B, 7D, and 7F ). In this way, endcap  1294  can cover all or part (e.g., in the dimension in which endcap  1294  is extended) of the second electrode layer  1220  not in contact with passivation layer  1204 , for example. In some examples, conformal layer  1206  can be placed on top of endcap  1294  to cover endcap  1294  and/or to cover part of the second electrode layer  1220  not covered by endcap  1294  (e.g., in the dimension in which endcap  1294  is not extended). 
     Further, in some examples, both of the first electrode layer  1210  and the second electrode layer  1220  can include exposed portions between endcaps  1272  or  1294  and the first passivation layer  1202  and second passivation layer  1204 , respectively. In some examples, both sides of touch screen  1200  can include an additional conformal layer (e.g., conformal layer  1206 ) to protect the first electrode layer  1210  and the second electrode layer  1220 . Although via  1270  is illustrated as connecting the first electrode layer  1210  and the second electrode layer  1220 , similar techniques can be used to protect a third electrode layer (e.g., third electrode layer  930  or  1030 ) using an endcap of a shield-shield via (e.g., shield-shield via  980  connecting first electrode layer  910  and third electrode layer  930  or shield-shield via  1080  connecting first electrode layer  1010  and third electrode layer  1030 ). Likewise, in some examples, additional passivation layers and/or conformal layers can be placed to cover the third electrode layer of a touch screen according to examples of the disclosure. 
     In some examples, substrate  1250  can include a material (e.g., a transparent and/or insulating material) that provides structural support to additional materials and/or layers of touch screen  1200 . Substrate  1250  can include a plurality of substrates joined by adhesive(s). The process for forming a touch screen  1200  as illustrated in  FIG. 12A  with passivation layers  1202  and  1204  and conformal layer  1206  will now be described with reference to  FIGS. 13A-13D . The process for forming a touch screen  1200  as illustrated in  FIG. 12B  with passivation layers  1202  and  1204  and conformal layer  1206  will be described below with reference to  FIGS. 14A-14D . 
       FIGS. 13A-13D  illustrate cross-sectional views of a portion of an exemplary touch screen  1300  including two passivation layers and a via between two electrode layers during a manufacturing process according to examples of the disclosure. In some examples, touch screen  1300  can include some or all of the same components as touch screen  900 ,  1000 , and/or  1200 . It should be understood that touch screen  900 ,  1000 , and/or  1200  can be manufactured using one or more of the steps described with reference to  FIGS. 13A-13D . 
       FIG. 13A  illustrates a partial view of exemplary touch screen  1300  during a first stage of a manufacturing process according to examples of the disclosure. In some examples, touch screen  1300  can include a first electrode layer  1310  (e.g., a top shielding layer), a second electrode layer  1320  (e.g., a touch sensing layer), a substrate  1350 , a first passivation layer  1302 , and a second passivation layer  1304 . In some examples, first electrode layer  1310 , second electrode layer  1320 , and substrate  1350  can form a two-layer structure. When first electrode layer  1310  and second electrode layer  1320  include electrodes including ITO, the two-layer structure can be a DITO layer. In some examples, first electrode layer  1310  and/or second electrode layer  1320  can include electrodes including other transparent, semi-transparent and/or opaque conductive materials. 
       FIG. 13B  illustrates a partial view of exemplary touch screen  1300  during a second stage of a manufacturing process according to examples of the disclosure. During the second stage, a hole  1376  can be formed in the touch screen  1300  using laser ablation or another suitable drilling technique. In some examples, the hole  1376  can have a first diameter  1378  across the first electrode layer  1310 , which can be smaller than a second diameter  1380  across the first passivation layer  1302 . The hole  1376  can have its largest diameter  1382  across the second passivation layer  1304 . By forming hole  1376  so that it is larger across the passivation layers  1302  and  1304  than it is across the electrode layers  1310  and  1320 , portions of the electrode layers  1310  and  1320  can be exposed to form electrical connections with a via, as will be described below. 
       FIG. 13C  illustrates a partial view of exemplary touch screen  1300  during a third stage of a manufacturing process according to examples of the disclosure. During the third stage, a via  1370  can be formed to fill hole  1376 , for example. In some examples, via  1370  can include endcaps  1372 . One of the endcaps  1372  can form an electrical connection to the first electrode layer  1310 . Another of the endcaps  1372  can form an electrical connection to the second electrode layer  1320 . In some examples, the endcaps  1372  can be electrically connected to one another by center portion  1374 . As shown in  FIG. 13C , one of the endcaps  1372  can completely overlap an exposed portion of first electrode layer  1310  that may not be covered by first passivation layer  1302 . Via endcap  1372  and first passivation layer  1302  can include non-corrosive materials, thereby protecting first electrode layer  1302  from corrosion. One of the endcaps  1372  can overlap part of an exposed portion of the second electrode layer  1320 , which can leave an exposed region of the second electrode layer between the via endcap and the second passivation layer  1304 . 
       FIG. 13D  illustrates a partial view of exemplary touch screen  1300  during a fourth stage of a manufacturing process according to examples of the disclosure. During the fourth stage, a conformal layer  1306  can be formed to cover the second electrode layer  1320  and the second passivation layer  1304 . Conformal layer  1306  can include a non-corrosive material, thereby protecting second electrode layer  1320 . 
     Although the stages of a manufacturing process have been described with reference to  FIGS. 13A-13D , in some examples, additional or alternative stages and/or steps are possible. Further, one or more stages of the manufacturing process described with reference to  FIGS. 13A-13D  can be used to form a touch screen including additional or alternative components to those included in touch screen  1300 . For example, touch screen  1300  can include additional adhesives, substrates, passivation layers, and/or conformal layers not illustrated. In some examples, touch screen  1300  can include additional electrode layers (e.g., to accommodate row and column touch electrodes as illustrated in  FIG. 4A ). 
       FIGS. 14A-14D  illustrate cross-sectional views of a portion of an exemplary touch screen  1400  including two passivation layers and a via between two electrode layers during a manufacturing process according to examples of the disclosure. In some examples, touch screen  1400  can include some or all of the same components as touch screen  900 ,  1000 , and/or  1200 . It should be understood that touch screen  900 ,  1000 , and/or  1200  can be manufactured using one or more of the steps described with reference to  FIGS. 14A-14D . 
       FIG. 14A  illustrates a partial view of exemplary touch screen  1400  during a first stage of a manufacturing process according to examples of the disclosure. The first stage illustrated in  FIG. 14A  can be similar to the first stage illustrated in  FIG. 13A  above. Touch screen  1400  can include a first electrode layer  1410  (e.g., a top shielding layer similar to first electrode layer  1310 ), a second electrode layer  1420  (e.g., a touch sensing layer similar to second electrode layer  1320 ), a substrate  1450  (e.g., similar to substrate  1350 , a first passivation layer  1402  (e.g., similar to first passivation layer  1302 ), and a second passivation layer  1404  (e.g., similar to second passivation layer  1304 ). In some examples, first electrode layer  1410 , second electrode layer  1420 , and substrate  1450  can form a two-layer structure. When first electrode layer  1410  and second electrode layer  1420  include electrodes including ITO, the two-layer structure can be a DITO layer. In some examples, first electrode layer  1410  and/or second electrode layer  1420  can include electrodes including other transparent, semi-transparent and/or opaque conductive materials. 
       FIG. 14B  illustrates a partial view of exemplary touch screen  1400  during a second stage of a manufacturing process according to examples of the disclosure. The second stage illustrated in  FIG. 14B  can be similar to the second stage illustrated in  FIG. 13B  above. During the second stage, a hole  1476  can be formed in the touch screen  1400  using laser ablation or another suitable drilling technique. In some examples, the hole  1476  can have a first diameter  1478  across the first electrode layer  1410 , which can be smaller than a second diameter  1480  across the first passivation layer  1402 . The hole  1476  can have its largest diameter  1482  across the second passivation layer  1404 . By forming hole  1476  so that it is larger across the passivation layers  1402  and  1404  than it is across the electrode layers  1410  and  1420 , portions of the electrode layers  1410  and  1420  can be exposed to form electrical connections with a via, as will be described below. 
       FIG. 14C  illustrates a partial view of exemplary touch screen  1400  during a third stage of a manufacturing process according to examples of the disclosure. The third stage illustrated in  FIG. 14C  can be similar to the third stage illustrated in  FIG. 13C  above. During the third stage, a via  1470  can be formed to fill hole  1476 , for example. In some examples, via  1470  can include endcaps  1472  and  1494 . One of the endcaps  1472  can form an electrical connection to the first electrode layer  1410 . Another of the endcaps  1494  can form an electrical connection to the second electrode layer  1420 . In some examples, the endcaps  1472  can be electrically connected to one another by center portion  1474 . As shown in  FIG. 14C , one of the endcaps  1472  can completely overlap an exposed portion of first electrode layer  1410  that may not be covered by first passivation layer  1402 . Via endcap  1472  and first passivation layer  1402  can include non-corrosive materials, thereby protecting first electrode layer  1402  from corrosion. As illustrated in  FIG. 14C , via  1470  can include at least one oval endcap  1494  with extended structure in one dimension (e.g., as illustrated in  FIGS. 7B, 7D, and 7F  above). In this way, endcap  1494  can cover all or part (e.g., in the dimension in which endcap  1494  is extended) of the second electrode layer  1420  not in contact with passivation layer  1404 , for example. In some examples, vias  1470  can include an oval endcap  1494  on one side and a circular endcap  1472  on the other side. In some examples, vias  1470  can include oval endcaps such as endcap  1494  on both sides. 
       FIG. 14D  illustrates a partial view of exemplary touch screen  1400  during a fourth stage of a manufacturing process according to examples of the disclosure. The fourth stage illustrated in  FIG. 14D  can be similar to the fourth stage illustrated in  FIG. 13D  above. During the fourth stage, a conformal layer  1406  can be formed to cover part, if any, of the second electrode layer  1420  not covered by passivation layer  1404 , and the second passivation layer  1404 . Conformal layer  1406  can include a non-corrosive material, thereby protecting part, if any, of second electrode layer  1420  and/or the via endcap  1494 . 
     Although the stages of a manufacturing process have been described with reference to  FIGS. 14A-14D , in some examples, additional or alternative stages and/or steps are possible. Further, one or more stages of the manufacturing process described with reference to  FIGS. 14A-14D  can be used to form a touch screen including additional or alternative components to those included in touch screen  1400 . For example, touch screen  1400  can include additional adhesives, substrates, passivation layers, and/or conformal layers not illustrated. In some examples, touch screen  1400  can include additional electrode layers (e.g., to accommodate row and column touch electrodes as illustrated in  FIG. 4A ). 
     Therefore, according to the above, some examples of the disclosure are related to a touch sensor panel comprising a first electrode layer comprising a first shielding electrode; a second electrode layer comprising one or more touch electrodes coupled to one or more routing traces; a third electrode layer comprising a second shielding electrode; a bond pad region comprising a plurality of connections to the one or more routing traces, the connections in the bond pad region different from connections between the one or routing traces and the one or more touch electrodes; a plurality of vias comprising: one or more first vias electrically coupling the first electrode layer and the second electrode layer, the one or more shield-sensor vias placed within the bond pad region; and one or more second vias electrically coupling the first electrode layer and the third electrode layer, wherein the second electrode layer is placed between the first electrode layer and the third electrode layer. Additionally or alternatively, in some examples, the one or more routing traces are coupled to touch sensing circuitry by way of the connections in the bond pad region. Additionally or alternatively, in some examples, each of the one or more routing traces comprises a first conductive portion in an inner region of the touch sensor panel and a second conductive portion in an outer region of the touch sensor panel, the outer region located around the inner region, wherein: the first conductive portions have a lower conductivity than the second conductive portions, and the one or more second vias are located in the outer region. Additionally or alternatively, in some examples, the one or more routing traces comprises a first routing trace coupled to a first touch electrode, the first touch electrode is a first distance from one of the one or more second vias, the first conductive portion of the first routing trace is longer than the first distance such that the first routing trace is separated from the one of the one or more second vias by at least a threshold distance. Additionally or alternatively, in some examples, the one or more routing traces comprises a first routing trace coupled to a first touch electrode, the first touch electrode is a first distance from one of the one or more second vias, the first routing trace further comprises a third conductive portion, the one of the one or more second vias placed between the third conductive portion and the second conductive portion, the first conductive portion of the first routing trace comprises a diverted portion connected to the second conductive portion and the third conductive portion such that the first routing trace is separated from the one of the one or more second vias by at least a threshold distance. Additionally or alternatively, in some examples, the first conductive portions include ITO and the second conductive portions include copper. Additionally or alternatively, in some examples, the touch sensor panel further includes an inner region, the inner region including the one or more touch electrodes; and a first opaque mask around the inner region, the first opaque mask comprising one or more notches, wherein the one or more second vias are placed in the one or more notches of the first opaque mask. Additionally or alternatively, in some examples, the touch sensor panel further includes a cover material located on an opposite side of the first electrode layer than the second electrode layer; and a second opaque mask placed on the cover material, the second opaque mask having an interior edge and an exterior edge, the interior edge located further from the one or more touch electrodes than an interior edge of the first opaque mask. Additionally or alternatively, in some examples, the touch sensor panel further includes a passivation layer placed on the first electrode layer and second electrode layer such that the first electrode layer is between the passivation layer and the second electrode layer, wherein: the first electrode layer includes a first hole, the second electrode layer includes a second hole, the passivation layer includes a third hole larger than the first hole, the first hole, second hole, and third hole overlap one another, and at least one of the one or more first vias placed within the first hole, second hole, and third hole comprises an endcap in contact with the first electrode layer, the endcap overlapping a region of the first electrode layer exposed by the third hole in the passivation layer. Additionally or alternatively, in some examples, the touch sensor panel further comprises a passivation layer placed on the first electrode layer and the second electrode layer such that the second electrode layer is located between the passivation layer and the first electrode layer; and a conformal layer on the second electrode layer and the passivation layer, wherein the first electrode layer includes a first hole, the second electrode layer includes a second hole, the passivation layer includes a third hole larger than the second hole, the first hole, second hole, and third hole overlap one another, one of the one or more first vias placed within the first hole, the second hole, and the third hole comprises an endcap in contact with the second electrode layer, the second electrode layer comprises an exposed region between the endcap and the passivation layer, and the conformal layer completely overlaps the exposed region of the second electrode layer. 
     Some examples of the disclosure are related to a method of sensing touch at a touch sensor panel, the method comprising: shielding noise using a first shielding electrode placed on a first electrode layer; sensing touch using one or more touch electrodes placed on a second electrode layer; shielding noise using a second shielding electrode placed on a third electrode layer; connecting, using one or more routing traces included in the second electrode layer, the one or more touch electrodes to one or more bond pad regions; electrically coupling, using one or more first vias placed in the one or more bond pad regions, the first electrode layer and the second electrode layer; electrically coupling, using one or more second vias placed outside the bond pad region, the first electrode layer and the third electrode layer; and driving the first, second, and third electrode layers to a same potential. Additionally or alternatively, in some examples, the method further includes sensing touch using touch sensing circuitry coupled to the one or more routing traces by way of one or more connections within the one or more bond pad regions. Additionally or alternatively, in some examples, the method further includes routing one or more signals from the one or more touch electrodes using the one or more routing traces coupled to the one or more touch electrodes, each routing trace comprising a first conductive portion in an inner region of the device and a second conductive portion in an outer region of the device, the outer region around the inner region, wherein: the first conductive portion has a lower conductivity than the second conductive portion, and the one or more second vias are located in the outer region. Additionally or alternatively, in some examples, the one or more routing traces comprises a first routing trace coupled to a first touch electrode, the first touch electrode is located a first distance from one of the one or more second vias, the first routing trace further comprises a third conductive portion, the one of the one or more second vias placed between a first metal portion and a second metal portion of the first routing trace, the first conductive portion of the first routing trace comprises a diverted portion connected to the second conductive portion and the third conductive portion such that the first routing trace is separated from the one of the one or more second vias by at least a threshold distance. Additionally or alternatively, in some examples, the first conductive portion includes ITO and the second conductive portion includes copper. Additionally or alternatively, in some examples, the one or more touch electrodes are placed within an inner region of the touch sensor panel, a first opaque mask is located around the inner region, the first opaque mask comprises one or more notches, and the one or more second vias are placed in the one or more notches of the first opaque mask. Additionally or alternatively, in some examples, the method further comprises covering, with a cover material overlapping the inner region and the first opaque mask, the first electrode layer, the second electrode layer, and the third electrode layer, wherein a second opaque mask is placed on the cover material, the second opaque mask having an interior edge and an exterior edge, the interior edge located further from the one or more touch electrodes than an interior edge of the first opaque mask. Additionally or alternatively, in some examples, the method further includes covering the first electrode layer and the second electrode layer with a passivation layer such that the first electrode layer is located between the passivation layer and the second electrode layer, wherein: the first electrode layer includes a first hole, the second electrode layer includes a second hole, the passivation layer includes a third hole larger than the first hole, the first hole, the second hole, and the third hole overlap one another, and one of the one or more first vias placed within the first hole, the second hole, and the third hole comprises an endcap in contact with the first electrode layer, the endcap overlapping a region of the first electrode layer exposed by the third hole in the passivation layer. Additionally or alternatively, in some examples, the method further includes covering the first electrode layer and the second electrode layer with a passivation layer such that the second electrode layer is between the passivation layer and the second electrode layer, wherein: the first electrode layer includes a first hole, the second electrode layer includes a second hole, the passivation layer includes a third hole larger than the second hole, the first hole, the second hole, and the third hole overlap one another, one of the one or more first vias placed within the first hole, the second hole, and the third hole comprises an endcap in contact with the second electrode layer, the second electrode layer comprises an exposed region between the endcap and the passivation layer, and a conformal layer placed on the second electrode layer and the passivation layer that overlaps the exposed region of the second electrode layer. 
     Some examples of the disclosure are related to a method of forming a touch sensor panel, the method comprising: forming a first shielding electrode on a first electrode layer; forming one or more touch electrodes on a second electrode layer; forming a second shielding electrode on a third electrode layer; forming one or more routing traces coupled to the one or more touch electrodes; forming a bond pad region comprising connections to the one or more routing traces, the connections in the bond pad region different from connections between the one or more routing traces and the one or more touch electrodes; forming, in the bond pad region, one or more first vias electrically coupling the first electrode layer and the second electrode layer; and forming one or more second vias electrically coupling the first electrode layer and the third electrode layer, wherein the second electrode layer is placed between the first electrode layer and the third electrode layer. Additionally or alternatively, in some examples, the one or more routing traces are coupled to touch sensing circuitry by way of the connections in the bond pad region. Additionally or alternatively, in some examples, each of the one or more routing traces comprises a first conductive portion in an inner region of the touch sensor panel and a second conductive portion in an outer region of the touch sensor panel, the outer region located around the inner region, wherein: the first conductive portion has a lower conductivity than the second conductive portion, and the one or more second vias are located in the outer region. Additionally or alternatively, in some examples, the one or more routing traces comprises a first routing trace coupled to a first touch electrode, the first touch electrode is a first distance from one of the one or more second vias, the first conductive portion of the first routing trace is longer than the first distance such that the first routing trace is separated from the one of the one or more second vias by at least a threshold distance. Additionally or alternatively, in some examples, the one or more routing traces comprises a first routing trace coupled to a first touch electrode, the first touch electrode is a first distance from one of the one or more second vias, the first routing trace further comprises third conductive portion, the one of the one or more second vias placed between the second conductive portion and the third conductive portion, the first conductive portion of the first routing trace comprises a diverted portion connected to the second conductive portion and the third conductive portion such that the first routing trace is separated from the one of the one or more second vias by at least a threshold distance. Additionally or alternatively, in some examples, the first conductive portion comprises ITO and the second conductive portion comprises copper. Additionally or alternatively, in some examples, the method further includes forming an inner region, the inner region including the one or more touch electrodes; forming a first opaque mask around the inner region, the first opaque mask comprising one or more recessed notches, wherein the one or more second vias are placed in the recessed notches of the first opaque mask. Additionally or alternatively, in some examples, the method further includes forming a cover material located on an opposite side of the first electrode layer than the second electrode layer; and forming a second opaque mask placed on the cover material, the second opaque mask having an interior edge and an exterior edge, the interior edge located further from the one or more touch electrodes than an interior edge of the first opaque mask. Additionally or alternatively, in some examples, the method further includes forming a passivation layer placed on the first electrode layer and second electrode layer such that the first electrode layer is between the passivation layer and the second electrode layer, wherein: the first electrode layer includes a first hole, the second electrode layer includes a second hole, the passivation layer includes a third hole larger than the first hole, the first hole, second hole, and third hole overlap one another, and at least one of the one or more first vias placed within the first hole, second hole and third hole comprises an endcap in contact with the first electrode layer, the endcap overlapping a region of the first electrode layer exposed by the third hole in the passivation layer. Additionally or alternatively, in some examples, the method further includes forming a passivation layer placed on the first electrode layer and the second electrode layer such that the second electrode layer is located between the passivation layer and the first electrode layer; and forming a conformal layer on the second electrode layer and the passivation layer, wherein: the first electrode layer includes a first hole, the second electrode layer includes a second hole, the passivation layer includes a third hole larger than the second hole, the first hole, second hole, and third hole overlap one another, one of the one or more first vias placed within the first hole, the second hole, and the third hole comprises an endcap in contact with the second electrode layer, the second electrode layer comprises an exposed region between the endcap and the passivation layer, and the conformal layer completely overlaps the exposed region of the second electrode layer. 
     Although examples have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the various examples as defined by the appended claims.

Metadata:
Filing Date: 20180927
Publication Date: 20191231
Grant Date: 20191231
Priority Date: 20170929
Inventors: SCHULTZ, DAVID SHELDON
SHARMA, Prithu
GAUBERT, ZACHARY M.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F3/0412", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04107", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04107", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0445", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04103", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04103", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0445", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/04164", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0416", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04107", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04103", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04164", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/041662", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04164", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/041662", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 63858207