HK1167032B - A method for fabricating touch sensor panels - Google Patents

Description

Method for manufacturing touch sensor panel

Technical Field

The present invention relates generally to touch sensor panel manufacturing and, more particularly, to a system and method for improving touch sensor panel manufacturing processes using a resist (resist) that acts as a mask during a photolithography/etch patterning process and as a passivation layer during a subsequent passivation process.

Background

In recent years, touch sensor panels, touch screens, and the like have been available as input devices. In particular, touch screens are becoming increasingly popular due to their ease and versatility of operation and their reduced price. The touch screen may include a touch sensor panel, which may be a transparent panel having a touch-sensitive surface, and a display device, which may be an LCD panel, and may be positioned partially or completely behind the touch sensor panel so that the touch-sensitive surface may cover at least a portion of the viewable area of the display device. In some devices, the touch screen is protected by a cover glass. Touch screens can allow a user to perform various functions by touching the touch sensor panel using a finger, stylus, or other object at a location typically dictated by a User Interface (UI) displayed by the display device. In general, a touch screen can recognize a touch event and the location of the touch event on the touch sensor panel, and the computing system can then interpret the touch event in accordance with the display appearing at the time of the touch event, and thereafter can perform one or more actions based on the touch event.

Similar to LCD panels, touch sensor panels in touch screens can be made of glass or other suitable transparent substrates. In some configurations, a touch sensor panel can be implemented as an array of pixels formed by a plurality of drive lines (e.g., rows) and a plurality of sense lines (e.g., columns) crossing, where the drive and sense lines are separated by a dielectric material. In some touch sensor panels, the drive and sense lines can be formed on both the top and bottom sides of the same transparent substrate. In other touch sensor panels, the drive and sense lines can be formed on one side of a transparent substrate. The sense and drive lines can be formed of a substantially transparent material, such as Indium Tin Oxide (ITO), although other materials can also be used. One or more ITO layers may be deposited on one or both sides of the transparent substrate. Touch sensor panels with double-sided or single-sided ITO layers are referred to herein as double-sided ITO (dito) and single-sided ITO (sito) touch sensor panels, respectively. DITO and SITO touch sensor panels are widely used in a wide variety of electronic devices, such as tablet PCs, digital music players, cellular phones, and other wireless handheld devices.

Existing methods of manufacturing touch sensor panels require multiple printing steps to be performed during the photolithography/etch patterning process and subsequent passivation process. Conventional photolithography/etching processes are expensive due to high equipment and material costs. Thus, it would be desirable if the number of printing steps in the manufacturing process could be reduced, thereby reducing the overall manufacturing cost of the touch sensor panel.

Disclosure of Invention

The present invention relates to a method for manufacturing a touch sensor panel. In some touch sensor panel manufacturing processes, a photoresist (photoresist) is applied to the panel during a photolithography/etch patterning process. After the lithography/etch patterning process is completed, the photoresist will be stripped. A separate passivation layer is then applied in a subsequent passivation process. Thus, the overall manufacturing process is lengthy and inefficient. Equipment and material costs are also relatively high due to the multiple printing and etching steps performed. Embodiments of the present disclosure seek to eliminate some of these steps by applying a resist that can act as a mask during the etching process and continue to permanently act as a passivation layer after the etching process. This improved process may eliminate multiple steps of existing manufacturing processes and may reduce equipment and material costs.

In one embodiment of the present disclosure, first, an ITO (or other conductive material) layer and a metal layer may be deposited on one or both surfaces of the substrate. Next, a photolithography/etching process is performed to pattern the ITO and metal layers to form the drive and sense elements of the touch sensor panel, although in other embodiments, other processes besides photolithography/etching may be used to remove the patterns. The first two steps may be the same as those in existing manufacturing processes. A resist/passivation material can then be placed over the edge regions of the touch sensor panel to protect the metal pattern in that region during subsequent photolithography/etching processes. This resist/passivation material differs from commonly used photoresists in that: this particular material may act as a mask during the photolithography/etching process and may also act as a passivation layer during the passivation process. After placing such dual purpose material in place, a second lithography/etch process may be performed to remove metal from the viewing area of the panel, although in other embodiments processes other than lithography/etching may be used to remove metal. Since the same material may also act as a passivation layer, the passivation process may be performed without first removing the photoresist and placing the passivation layer over the edge region or the entire surface.

In summary, embodiments of the present disclosure can reduce the number of steps required in a touch sensor panel manufacturing process. More importantly, by using a single material as a photoresist mask during the photolithography/etching process and as a passivation layer during the passivation process, the material and operating costs associated with the printing process in the manufacturing process and the process of removing additional material may be reduced. As a result, the overall manufacturing process may be more efficient and the overall cost of the finished device containing the touch sensor panel may be reduced.

Drawings

Fig. 1 illustrates an exemplary stacked structure of a touch sensor panel.

Fig. 2-5 provide step-by-step illustrations of exemplary steps of an existing touch sensor panel manufacturing process.

Fig. 6 is a flow chart illustrating steps of the manufacturing process shown in fig. 2-5.

Fig. 7 and 8 illustrate exemplary steps of a touch sensor panel manufacturing process according to an embodiment of the present disclosure.

FIG. 9 is a flow chart illustrating steps of a manufacturing process according to an embodiment of the present disclosure.

Fig. 10-14 illustrate exemplary steps of one method of preserving a bond area for a flexible bond in the manufacturing process shown in fig. 9, in accordance with an embodiment of the present disclosure.

Fig. 15 and 16 illustrate exemplary steps of another method of preserving a bond area for a flexible bond in the manufacturing process shown in fig. 9, in accordance with an embodiment of the present disclosure.

Fig. 17-19 illustrate exemplary steps of yet another method of preserving a bond area for a flexible bond in the manufacturing process shown in fig. 9, in accordance with an embodiment of the present disclosure.

FIG. 20a illustrates an exemplary digital media player having a SITO or DITO touch sensor panel made according to embodiments of the disclosure.

FIG. 20b illustrates an exemplary mobile phone with a SITO or DITO touch sensor panel made according to embodiments of the disclosure.

FIG. 20c illustrates an exemplary mobile computer with a SITO or DITO touch sensor panel made according to embodiments of the disclosure.

FIG. 20d illustrates an exemplary desktop computer with a SITO or DITO touch sensor panel made according to embodiments of the disclosure.

FIG. 21 illustrates an exemplary computing system incorporating a touch sensor panel made in accordance with embodiments of the disclosure.

Detailed Description

In the following description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments that can be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the embodiments of the present disclosure.

The present invention relates to a method for manufacturing a touch sensor panel. In some touch sensor panel manufacturing processes, photoresist is applied to the panel during a photolithography/etch patterning process. The photoresist is stripped after the lithography/etch patterning process is complete. A separate passivation layer is then applied in a subsequent passivation process. Thus, the overall manufacturing process is lengthy and inefficient. Equipment and material costs are also relatively high due to the multiple printing and etching steps performed. Embodiments of the present disclosure seek to eliminate some of the above steps by applying a resist that acts as a mask in the etching process and still permanently acts as a passivation layer after the etching process. This improved process can eliminate multiple steps of existing manufacturing processes and can reduce equipment and material costs.

The structure of a capacitive touch sensor panel is shown in fig. 1. The touch sensor panel 100 can include a substrate 102. The substrate may be a flexible material such as polyethylene terephthalate (PET) or Polycarbonate (PC). In some embodiments, a rigid material such as glass may also be used as the substrate. As shown in fig. 1, an ITO (or other conductive material) layer 104 may be deposited on the top surface of the substrate 102. The ITO layer 104 can later be patterned to form sense lines and/or drive lines of the touch sensor panel 100. Deposited over the ITO layer 104 is a metal layer 106 for forming routing traces on the touch sensor panel 100. The metal layer 106 can be made of copper or any other metal suitable for routing signals detected by the sense lines to circuitry (not shown in FIG. 1) attached to the touch sensor panel 110 for further processing. The ITO layer 104 and the metal layer 106 may be deposited back-to-back, sequentially, or simultaneously on the substrate 102.

The SITO touch sensor panel can be fabricated using the above-described stacked structure, which includes a metal layer 106 and an ITO (or other conductive material) layer 104 deposited over a substrate 102. Alternatively, additional layers (shown in dashed lines in FIG. 1) can be added to the stack structure to form the underlying structure of the DITO touch sensor panel. As previously mentioned, DITO touch sensor panels typically have drive and sense lines formed on opposite surfaces of a substrate. In the exemplary embodiment shown in fig. 1, the bottom surface of the substrate 102 may be attached to a second substrate 108 with a layer of bonding agent 110 (e.g., an optically clear bonding agent (OCA)) between the substrate 102 and the second substrate 108. The second substrate 108 may likewise be made of a material such as PET, PC, glass, or other suitable material. An ITO (or other conductive material) layer 112 and a metal layer 114 may be deposited on the bottom surface of the second substrate in the same manner as described above with respect to the top surface of the substrate 102. As shown in fig. 1, the resulting stack structure includes a layered substrate 102, 108 in the middle, ITO (or other conductive material) layers 104, 112 on the top and bottom surfaces of the layers, and metal layers 106, 114.

In some touch sensor panel manufacturing processes, a number of additional patterning and passivation steps must be performed to further process the delamination of fig. 1 to form a touch sensor panel. Fig. 2-5 provide exemplary step-by-step illustrations of the remaining processing. Although only the upper half of the stacked structure of fig. 1 is shown in fig. 2-5 and a description of the processing for the upper half is provided, it should be understood that the lower half of the stacked structure may be processed simultaneously or after the upper half is processed in a similar manner as the upper half.

FIG. 2 shows the stacked structure of FIG. 1 after an initial lithographic/etch patterning process is performed on the ITO (or other conductive material) layer 104 and the metal layer 106 to form the drive and sense elements of the touch sensor panel. As shown, thin film patterns of layers 104, 106 may be formed as a result of this initial patterning step. More specifically, the pattern in the viewing area 116 of the panel can serve as conductive traces (i.e., drive or sense lines) for the touch sensor panel 100. The metal pattern in the panel edge area 118 may be used as a routing trace to route signals to a flex circuit (not shown). This initial step may be performed using any well-known lithography/etching technique.

In a next step shown in fig. 3, the remaining metal pattern in viewing area 116 of touch sensor panel 100 (corresponding to the embodiment in which layer 104 is transparent) can be removed, whereby viewing area 116 can be transparent. In the prior art, a strip of photoresist 120 may be printed on an edge region 118 (e.g., the region around the viewing area) of the surface of the panel 100 to protect the metal traces in that region. Other types of resists, such as heat resists, may also be used depending on the type of lithography/etch process being performed. Thereafter, by performing a metal etch, any remaining metal in the viewing area 116 that is not protected by the photoresist 120 may be removed. As a result, only a pattern of ITO 122 remains in the viewing area 116.

In a next step, as shown in FIG. 4, the photoresist strips may be removed from the edge area 118 of the touch sensor panel, exposing the protected metal pattern 106. Only the transparent ITO pattern 122 remains in the viewing area 116.

The touch sensor panel then undergoes a passivation step. Before the passivation process can be performed, a passivation layer 122 can be placed on the edge region 118 over the metal traces 106 (as shown in FIG. 5) or on the entire surface of the touch sensor panel including both the viewing region 116 and the edge region 118. Once the passivation layer 122 is in place, a passivation process may be performed.

Fig. 6 provides a flow chart summarizing the above-described manufacturing process steps. First, an ITO (or other conductive material) layer and a metal layer may be deposited on the surface of the substrate (step 600). A photolithography/etching process may then be performed to pattern both the ITO and metal layers to form the sensing and driving elements and routing traces (step 601). A photoresist may then be placed over the edge region of the touch sensor panel surface to protect the metal pattern in that region (step 602). A second photolithography/etching step may be performed to remove remaining metal in the viewing area of the touch sensor panel (step 603). Thereafter, the photoresist may be removed from the edge region, thereby exposing the underlying metal pattern. Before performing the passivation process on the touch sensor panel (step 605), a separate passivation layer may be placed on an edge region or the entire surface of the touch sensor panel (step 604).

As detailed above, the touch sensor panel manufacturing process described above requires multiple steps that can make the process tedious and inefficient. Furthermore, another disadvantage of the above method is that: the cost of equipment and materials may be high due at least to the application and removal of the photoresist and the subsequent separate application of the passivation layer. By using a single material as a resist in a lithography/etch process and as a passivation layer during a passivation process, embodiments of the present disclosure reduce the number of steps and associated material costs, thereby simplifying the above-described processes.

In one embodiment, the manufacturing process begins by performing the same lithography/etch patterning steps for the metal layer and the ITO (or other conductive material) layer on one or both surfaces of the layer structure shown in FIG. 2, although in other embodiments other processes than lithography/etch may be used to form the pattern. Next, rather than placing a strip of photoresist (or other type of resist depending on the etching process) in the edge region of the touch sensor panel to protect the metal traces along the edge during the etching process as shown in fig. 3, a resist/passivation material 420 that acts as both a photoresist (or other type of resist depending on the etching process) and a passivation layer may be placed in the edge region 418 of the panel 400 as shown in fig. 7. The resist/passivation material 420 may be, for example, from DuPont imaging materialOf the series or from Asahi Kasei e-materialSeries of Dry Film Resists (DFR), or any other suitable material that can act as a resist and passivation material. The resist/passivation material 420 may be printed on the edge region using known printing methods such as screen printing and DFR methods. The resist/passivation material 420 can cover the patterned metal traces 406 in the edge regions of the touch sensor panel and can expose the metal pattern 430 in the viewing region 416 without any protection.

In a next step, as shown in FIG. 8, a second lithography/etch step may be performed to remove the metal pattern 430 in the viewing area 416 of the panel 400, although in other embodiments processes other than lithography/etch may be used to remove the pattern. Since the resist/passivation material 420 may act as a photoresist, the metal traces 406 in the edge region 418 are not etched away. This step is similar to the step shown in fig. 3.

Using the method described above, the next two steps shown in fig. 4 and 5 are to remove the photoresist from the edge region and then place a passivation layer for the passivation step. In contrast, because the resist/passivation material 420 may also act as a passivation layer, the steps of removing the photoresist and placing the passivation layer in the prior art methods may be eliminated. Thus, the resist/passivation material 420 will permanently remain on the edge region 418 and will not be removed or replaced. That is, the passivation process may be performed after the second photolithography/etching step without any additional steps in between.

Fig. 9 is a flowchart illustrating exemplary steps of a touch sensor panel manufacturing process according to the above-described embodiments. First, an ITO (or other conductive material) layer and a metal layer may be deposited on one or both surfaces of a substrate (step 900). Next, a photolithography/etching process is performed to pattern both the ITO and metal layers to form the drive and sense elements of the touch sensor panel (step 901), although other processes besides photolithography/etching may be used to remove the patterns in other embodiments. These two previous steps may be the same as those in the existing manufacturing process (see, e.g., steps 600 and 601 in fig. 6). A resist/passivation material may then be placed over the edge region of the touch sensor panel to protect the metal pattern of that region during subsequent photolithography/etching processes (step 902). This resist/passivation material differs from commonly used photoresists in that: this particular material may act as a mask during the photolithography/etching process and may also act as a passivation layer during the passivation process. After placing this dual purpose material in place, a second lithography/etch process may be performed to remove metal from the viewing area of the panel (step 903), although in other embodiments processes other than lithography/etching may be used to remove metal. Since this material can also act as a passivation layer, the passivation process (step 904) can be performed without first removing the photoresist and placing a passivation layer on the edge region or the entire surface.

In general, embodiments of the present disclosure can reduce the number of steps required in the manufacturing process of a touch sensor panel. More importantly, by using a single material as both a photoresist mask during the photolithography/etching process and a passivation layer during the passivation process, the material and operating costs associated with the process of printing and removing additional material in the manufacturing process can be reduced. As a result, the overall manufacturing process may be more efficient and the overall cost of the finished device containing the touch sensor panel may be reduced.

As previously described, signals detected by the touch sensor panel can be passed to a flex circuit for further processing to determine, for example, the nature and location of one or more touches detected on the touch sensor panel. In one embodiment, the signal may be delivered to a flexible circuit bonded to a region near or within the panel edge region. The flexible circuit may be typically bonded to a metal layer or ITO (or other conductive material) layer of the panel. However, once the touch sensor panel surface has undergone passivation and a passivation layer has been deposited over the metal layer and the ITO layer, it may be difficult or impossible to attach the flexible circuit to the panel. In the above embodiments, once the material used as both the resist and the passivation layer is deposited, the material can permanently remain over the edge region. In other words, the material may not be removed or replaced prior to the passivation process to allow for the retention of possible link regions. Thus, there is a problem of connecting the flexible circuit to the metal/ITO layer under the resist. Three different solutions are provided in the following, wherein these solutions solve this problem by ensuring that the junction area remains in the process, even in case a resist/passivation layer is permanently placed on the panel edge area.

The first embodiment comprises: a temporary bond mask is printed on the bond areas prior to printing the resist/passivation material on the bond areas. FIGS. 10-14 provide step-by-step illustrations of the method.

FIG. 10 shows a top view of an exemplary touch sensor panel 1000 having a patterned ITO (or other conductive material) layer and a metal layer (pattern not shown in this figure) deposited on its surface. The patterning process may be performed by a conventional photolithography/etching process or other processes. In a next step, as shown in FIG. 11, a temporary mask (e.g., a strip mask) 1010 may be placed over the attachment area of touch sensor panel 1000 in order to protect the metal layer below that area. Once the temporary mask is in place, a resist/passivation layer 1020 may be printed over the entire edge area of panel 1000 as shown in fig. 12. Since the link areas are covered by temporary mask 1010 (not shown in fig. 12), resist/passivation layer 1020 does not adhere directly to the metal layer in this particular area. Instead, resist/passivation layer 1020 will adhere to temporary mask 1010. Fig. 13 shows another metal lithography/etching step to remove the metal pattern from the viewing area 1030 of the panel 1000, although in other embodiments other processes than lithography/etching may be used to remove the metal. After the etching process, only the ITO (or other conductive material) pattern 1000 will remain in the viewing area 1030. As described above, the resist/passivation layer material is not removed after the metal lithography/etching step, since it can also act as a passivation layer. To expose the metal layer at the bonding areas 1040 for subsequent flexible bonding processing, the temporary mask may be stripped or otherwise removed, as shown in fig. 14, thereby exposing the bonding areas 1040. The resist/passivation layer over the link area can thereby be removed along with the temporary mask (since they are attached to each other). During the flex bonding process, the flex circuit may be bonded to the metal layer in the bonding area 1040. Since the temporary mask is relatively inexpensive, using the mask to temporarily prevent the metal layer in the bonding area from being removed during the etching process does not significantly increase the material cost of the overall manufacturing process, nor does it reduce the benefits of using the manufacturing process disclosed in the above embodiments.

A second method for ensuring that the link regions remain during and after the passivation process is to avoid printing the resist/passivation material completely over the link regions. As shown in fig. 15, after photolithography/etching (or other similar process) is performed on the metal and ITO (or other conductive material) layers to form a pattern, a resist/passivation material 1020 'may be printed on the edge regions of the panel except for the portion 1040' that is reserved for flexible bonding processing later in the manufacturing process, thereby exposing the metal layer in the bonding region. Next, a second metal lithography/etch (or other similar process) may be performed to remove metal in areas not protected by the resist/passivation material 1020'. Since the link regions 1040 'are not protected by the resist/passivation material 1020' in this embodiment, this photolithography/etching process removes not only the metal pattern in the viewing regions 1030 ', but also the metal layer in the link regions 1040', as shown in fig. 16. As a result, the patterned ITO (or other conductive material) layer is a layer that is exposed in both the viewing area 1030 'and the link area 1040'. In this embodiment, the flex circuit may be bonded directly to the exposed ITO layer in the bonding area 1040'.

In a third embodiment, the flexible joint region may remain in the extended region 1050 of the touch sensor panel 1000 "rather than within the edge region 1040 of the previous embodiment. As shown in fig. 17, the extended area 1050 may be a "flexible tail" 1050 extending from one side of the touch sensor panel 1000 ". In this embodiment, a layer of ITO (or other conductive material) and a layer of metal may be deposited on the surface of touch sensor panel 1000 "that includes the surface of extended area 1050. A first photolithography/etching step (or similar process) may be performed as usual to form a pattern in the ITO and metal layers. As shown in FIG. 18, a resist/passivation material 1020 "can be printed on the edge area 1020" of the touch sensor panel 1000 "and can optionally be printed on a portion of the extended area (i.e., the" flex tail ") before the metal pattern of the panel viewing area 1030" is etched away. At least a portion 1060 of extension region 1050 may not be covered by resist/passivation layer 1020 ". A second lithography/etch step (or other similar process) may remove metal in the viewing area 1030 in the extension region not covered by the resist/passivation material 1020 "and in a portion 1060 of the extension region (i.e., the" flex tail "). As shown in fig. 19, the patterned ITO (or other conductive material) layer may be exposed in these exposed regions 1030 ", 1060. Thus, the flex circuit can be bonded directly to the ITO layer of the unprotected portion 1060 in the extended area 1050 during a subsequent flex bonding process.

The three embodiments discussed above may allow for permanent placement of the resist/passivation material over the touch sensor panel while still leaving at least one area of the panel (or panel extension) surface for flexible attachment.

Fig. 20a illustrates an exemplary digital media player 2010 that can include a touch sensor panel 2015 manufactured according to embodiments of the disclosure.

Fig. 20b illustrates an exemplary mobile telephone 2020 that can include a touch sensor panel 2025 made in accordance with embodiments of the disclosure.

FIG. 20c shows an exemplary personal computer 2044 that can contain a touch sensor panel 524 and a display device 2030. The touch sensor panel 2024 can be a SITO/DITO or other panel manufactured according to embodiments of the disclosure. Display device 2030 may also include a SITO/DITO or other panel fabricated according to embodiments of the present disclosure.

Fig. 20d shows a desktop computer 2090 containing a display device 2092. The display device 2092 may include a SITO/DITO or other panel made in accordance with embodiments of the present disclosure. Desktop computer 2090 may also include a virtual keyboard 2094 incorporating a SITO/DITO or other front panel made in accordance with embodiments of the present disclosure.

FIG. 21 illustrates an exemplary computing system 2100 that can contain one or more DITO/SITO or other touch sensor panels fabricated in accordance with embodiments disclosed above. The computing system 2100 may include one or more panel processors 2102 and peripherals 2104, as well as a panel subsystem 2106. Peripheral devices 2104 may include, but are not limited to: random Access Memory (RAM) or other types of memory or storage, watchdog timers and the like. Panel subsystem 2106 may include, but is not limited to: one or more sense channels 2108, channel scan logic 2110, and driver logic 2114. Channel scan logic 2110 may access RAM 2112, automatically read data from the sense channels, and provide control for the sense channels. In addition, channel scan logic 2110 can control driver logic 2114 to generate stimulation signals 2116 at various frequencies and phases, and these signals can be selectively applied to drive lines of touch sensor panel 2124. In some embodiments, the panel subsystem 2106, the panel processor 2102, and the peripherals 2104 may be integrated in a single Application Specific Integrated Circuit (ASIC).

Touch sensor panel 2124 can include a capacitive sensing medium having a plurality of drive lines and a plurality of sense lines, although other sensing media can also be used. According to embodiments of the present disclosure, one or both of the drive and sense lines may be coupled to a thin glass sheet. Each intersection of the drive and sense lines can represent a capacitive sensing node and can be viewed as picture element (pixel) 2126, which can be particularly useful if touch sensor panel 2124 is viewed as capturing an "image" of touch. (in other words, after panel subsystem 2106 has determined whether a touch event has been detected at each touch sensor of the touch sensor panel, the touch sensor pattern in the multi-touch panel at which the touch event occurred can be considered a touch "image" (e.g., a pattern of finger contact with the panel.) Each sense line in touch sensor panel 2124 can drive sense channel 2108 (also referred to herein as an event detection and demodulation circuit) in panel subsystem 2106.

The computing system 2100 may also include a host processor 2128 to receive an output from the panel processor 2102 and perform operations based on the output, where the operations may include, but are not limited to: moving an 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 an instruction, operating a peripheral device coupled to a host device, answering a telephone call, initiating a telephone call, terminating a telephone call, changing volume or audio settings, storing information associated with telephone communications such as addresses, frequently dialed numbers, received calls, missed calls, logging into a computer or computer network, granting authorized individuals access to a limited area of the computer or computer network, loading a user profile associated with a user-preferred computer desktop arrangement, granting access to web content, launching a particular program, encrypting or decoding a message, and the like. Host processor 2128 may also perform additional functions not associated with panel processing and may be coupled to program storage 2132 and a display device 2130, such as an LCD panel, to provide a UI to a device user. When the display device 2130 is positioned partially or completely below the touch sensor panel, the display device 2130 together with the touch sensor panel 2124 can form a touch screen 2118.

It should be noted that one or more of the functions described above can be performed by firmware stored in memory (e.g., one of the peripherals 2104 in fig. 21) and executed by the panel processor 2102 or can be stored in the program storage 2132 and executed by the host processor 2128. The firmware can be stored and/or transmitted in any 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 disclosure, a "computer-readable storage medium" can be any medium 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 may 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 as a CD, CD-R, CD-RW, DVD-R, or DVD-RW, or a 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 propagation 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 disclosure, a "transmission 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 transmission readable medium may include, but is not limited to: an electronic, magnetic, optical, electromagnetic, or infrared wired or wireless propagation medium.

Although the embodiments of the present disclosure 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 embodiments of the present disclosure as defined by the appended claims.

Claims (20)

1. A method of manufacturing a touch sensor panel, comprising:

providing a substrate for a touch sensor panel;

depositing a layer of conductive material on a top surface of a substrate;

depositing a metal layer atop the layer of conductive material;

applying a temporary strip mask on the joining area of the first area of the metal layer;

attaching a resist to the first region of the metal layer and the temporary strip mask, the resist also acting as a passivation layer during passivation;

removing metal from the metal layer outside the first region; and

a passivation process is performed on the substrate while keeping the attached resist intact.

2. The method of claim 1, wherein the resist is a photoresist.

3. The method of claim 1, wherein the resist is a thermal resist.

4. The method of claim 1, wherein removing metal from the metal layer is accomplished by photolithography.

5. The method of claim 1, wherein removing metal from the metal layer is accomplished by etching.

6. The method of claim 1, further comprising:

the temporary strip mask and the resist attached to the temporary strip mask over the bond areas are removed to expose the bond areas for bonding of the flexible circuit.

7. The method of claim 1, further comprising: the flexible circuit is bonded to the bonding area.

8. The method of claim 1, wherein the first region of the metal layer does not include a bonding area reserved for flexible circuit bonding.

9. The method of claim 8, wherein the linking area is located on an extended area of the touch sensor panel.

10. The method of claim 1, further comprising: the layer of conductive material and the layer of metal are patterned to form drive and sense elements of the touch sensor panel.

11. The method according to claim 10, wherein the patterning process uses a Dry Film Resist (DFR).

12. The method of claim 10, wherein the patterning is accomplished by etching.

13. The method of claim 1, wherein the layer of conductive material and the layer of metal are deposited simultaneously.

14. A method of manufacturing a touch sensor panel, comprising:

forming a plurality of traces on a substrate;

applying a temporary tape mask over the joint area of the first portion of the trace;

depositing a first material over the first portion of traces and the temporary strip mask, the first material being adapted to act as both a photoresist and a passivation layer;

removing those traces not covered by the first material; and

passivating the substrate while leaving the deposited first material intact.

15. The method of claim 14, wherein the removing of the traces is accomplished by photolithography.

16. The method of claim 14, wherein the removing of the traces is accomplished by etching.

17. The method of claim 14, further comprising:

the temporary strip mask and the first material attached to the temporary strip mask over the bond areas are removed to expose the bond areas for bonding of the flexible circuit.

18. The method of claim 14, wherein the first portion of the trace does not include a bond area reserved for flex circuit bonding.

19. The method of claim 18, wherein the linking area is located on an extended area of the touch sensor panel.

20. The method of claim 14, wherein the traces are copper.