TWI550458B - Touch panel - Google Patents

Description

Touch panel

The invention relates to touch technology, in particular to a touch panel.

Touch panels or touch screens are increasingly used in electronic devices, particularly portable or handheld electronic devices such as personal digital assistants (PDAs) or mobile phones. With the demand of applications, a thin touch panel has been developed in recent years. The touch panel includes a substrate, a sensing electrode layer on the substrate, and a wire on the substrate, wherein the wire is electrically connected to the sensing electrode layer, and the wire is disposed outside the sensing electrode layer. The touch panel is susceptible to electrostatic breakdown during normal use, thereby affecting the use of the touch panel and product life.

In view of this, the present invention is directed to an improvement of the existing touch panel, which can meet the requirements of electrostatic protection.

An embodiment of the present invention provides a touch panel including a substrate divided into a touch area and a peripheral area surrounding the touch area, and a touch sensing electrode layer located in the touch area and a portion of the substrate. a plurality of signal wires disposed in a peripheral region of the substrate and electrically connected to the touch sensing electrode layer; and a plurality of ground wires located at the periphery of the touch sensing electrode layer and the plurality of signal wires And electrically insulated from each other.

In an embodiment of the invention, the touch sensing electrode layer includes a first one arranged in a first direction Sensing the conductor, the plurality of signal wires comprising a plurality of first wires connected to the first sensing conductor, and the parallel portions of the plurality of first wires and the grounding wires are separated from each other by a first spacing, The minimum distance between the plurality of ground lines and the plurality of first wires is separated by a first predetermined spacing, and the first predetermined spacing is greater than the first spacing.

In an embodiment of the invention, the first predetermined spacing is between 20 microns and 60 microns.

In an embodiment of the invention, the touch sensing electrode layer includes a second sensing conductor arranged along a second direction, the second direction intersecting the first direction, and the first sensing conductor and the second sensing conductor Electrically insulated, and wherein the plurality of signal wires comprise a plurality of second wires connected to the second sensing conductor, wherein the plurality of second wires and the ground wire parallel portions are separated from each other by a second pitch And the shortest distance between the plurality of ground lines and the plurality of second wires is separated by a second predetermined spacing, and the second predetermined spacing is greater than the second spacing.

In an embodiment of the invention, the second predetermined spacing is between 20 microns and 60 microns.

The embodiment of the present invention further includes a signal shielding line disposed in a peripheral region of the substrate and disposed between the plurality of first wires and the plurality of second wires to separate the plurality of wires a first wire and the plurality of second wires.

In an embodiment of the invention, an insulating block is disposed between the plurality of ground lines.

In an embodiment of the invention, the material of the plurality of grounding wires is selected from the group consisting of silver, molybdenum aluminum molybdenum, gold, copper, and indium tin oxide.

In an embodiment of the invention, one of the plurality of ground lines and the other ground line are formed of different materials.

In an embodiment of the invention, a shielding layer is disposed in the peripheral region of the substrate, and the plurality of signal wires and the plurality of ground wires are formed on the shielding layer.

The touch panel of the present invention further includes a touch panel and a peripheral area surrounding the touch area; a touch sensing electrode layer located in the touch area of the substrate and a plurality of signal wires are disposed in a peripheral region of the substrate and electrically connected to the touch sensing electrode layer; and a grounding wire is disposed in the peripheral region and includes one or more non-conductive regions.

In an embodiment of the invention, the one or more non-conductive regions comprise a continuous non-conductive block.

In an embodiment of the invention, the one or more non-conductive regions comprise a plurality of discrete non-conductive blocks.

In an embodiment of the invention, the touch sensing electrode layer includes a first sensing conductor arranged along a first direction, the plurality of signal wires comprising a plurality of first wires connected to the first sensing conductor, and the plurality of wires The parallel portions of the first wire and the grounding wire are separated from each other by a first spacing, and wherein the shortest distance between the grounding wire and the plurality of first wires is separated by a first predetermined spacing, and the first The predetermined spacing is greater than the first spacing.

In an embodiment of the invention, the first predetermined spacing is between 20 microns and 60 microns.

In an embodiment of the invention, the touch sensing electrode layer includes a second sensing conductor arranged along a second direction, the second direction intersecting the first direction, and the first sensing conductor and the second sensing conductor Electrically insulated, and wherein the plurality of signal wires comprise a plurality of second wires connected to the second sensing conductor, wherein the plurality of second wires and the ground wires are parallel to each other at a second pitch Separating, wherein the shortest distance between the ground line and the plurality of second wires is separated by a second predetermined spacing, and the second predetermined spacing is greater than the second spacing.

In an embodiment of the invention, the second predetermined spacing is between 20 microns and 60 microns.

According to an embodiment of the present invention, when the touch panel is attacked by ESD, the ESD defense is assumed. The protective ground wire protects the first and second wires from ESD attacks. Moreover, the plurality of grounding wires are beneficial for achieving multiple electrostatic protection of the first and second wires, that is, when one of the grounding wires is damaged by ESD, the other grounding wires can still work normally. In addition, the ground lines may partially overlap each other and be electrically insulated from each other, so that the area of the peripheral area may be reduced to facilitate the narrow bezel design. In addition, the configuration of a single grounding wire can also reduce the area of the surrounding area and facilitate the design of a narrow bezel.

10‧‧‧Touch panel

11‧‧‧First sensing conductor

12‧‧‧Second sensing conductor

15‧‧‧Bridge

16‧‧‧ glass substrate

17‧‧‧Touch sensing electrode layer

18‧‧‧Signal Shielding Line

20‧‧‧ touch area

30‧‧‧The surrounding area

32‧‧‧Touch panel

34‧‧‧Shielding layer

40‧‧‧Touch panel

50‧‧‧Touch panel

58‧‧‧ Non-conductive area

80‧‧‧Touch panel

84‧‧‧Insulation block

110‧‧‧First wire

120‧‧‧second wire

581‧‧‧Continuous non-conductive blocks

582‧‧‧Discontinuous non-conductive blocks

831‧‧‧First grounding wire

832‧‧‧Second grounding wire

D1‧‧‧first wire spacing

D2‧‧‧Second wire spacing

DG‧‧‧ Grounding wire spacing

G‧‧‧Grounding wire

G1‧‧‧ grounding wire

G2‧‧‧ grounding wire

G1A‧‧‧ pin

G1B‧‧‧ pin

G2A‧‧‧ pin

G2B‧‧‧ pin

PD1‧‧‧ first predetermined spacing

PD2‧‧‧second predetermined spacing

The foregoing summary of the invention, as well as the above detailed description For the purposes of illustrating the invention, various embodiments are shown in the drawings. However, it should be understood that the invention is not limited to the precise arrangements and devices disclosed.

1 is a schematic view of a touch panel according to an embodiment of the present invention; FIG. 2A is a cross-sectional view of the touch panel along the AA' direction of FIG. 1 according to an embodiment of the present invention; 2B is a cross-sectional view of the touch panel along the BB' direction of FIG. 1 according to an embodiment of the present invention; FIG. 3 is a partial cross-sectional view of the touch panel according to an embodiment of the present invention; 4 is a schematic diagram of a touch panel according to an embodiment of the invention; FIG. 5 is a schematic diagram of a touch panel according to an embodiment of the invention; Embodiments, a schematic diagram of a grounding wire configuration; FIG. 7 is a schematic view showing a grounding wire structure according to an embodiment of the present invention; and FIG. 8 is a partial cross-sectional view of a touch panel according to an embodiment of the present invention. .

FIG. 1 is a schematic diagram of a touch panel 10 according to an embodiment of the present disclosure. Referring to FIG. 1 , the touch panel 10 includes a substrate 16 , a touch sensing electrode layer 17 , a plurality of signal wires 110 , 120 , and a plurality of ground lines G1 and G2 .

The substrate 16 is divided into a touch area 20 (shown by a broken line frame) and a peripheral area 30 surrounding the touch area 20 . In an embodiment of the invention, the material of the substrate 16 may be selected from the group consisting of glass, acrylic (PMMA), polyvinyl chloride (PVC), polypropylene (PP), and polyethylene terephthalate (PET). Transparent materials such as polyethylene naphthalate (PEN), polycarbonate (PC), and polystyrene (PS).

The touch sensing electrode layer 17 is located in the touch area 20 and a portion of the peripheral area 30. The signal wires 110 and 120 are located in the peripheral region 30 of the substrate 16 and electrically connected to the touch sensing electrode layer 17 . In detail, the touch sensing electrode layer 17 includes a first sensing conductor 11 arranged in a first direction and a second sensing conductor 12 arranged in a second direction. The first sensing conductors 11 and the second sensing conductors 12 are configured as a sensing array, wherein the first sensing conductors 11 are arranged in columns and the second sensing conductors 12 are arranged in rows. Moreover, in the sensing array, the second sensing conductors 12 of the same row are electrically connected by electrical connections (not shown), and the first sensing conductors 11 of the same row are electrically connected by the bridges 15 . The electrical connection is electrically insulated from the bridge portion 15.

In an embodiment of the present invention, the materials of the first sensing conductor 11 and the second sensing conductor 12 may include various transparent conductive materials, for example, indium tin oxide (ITO), indium zinc (indium zinc) Oxide; IZO), cadmium tin oxide (CTO), aluminum zinc oxide (AZO), indium tin zinc oxide (ITZO), zinc oxide, cadmium oxide Cadmium oxide), hafnium oxide (HfO), indium gallium zinc oxide (InGaZnO), indium gallium zinc magnesium oxide (InGaZnMgO), indium gallium magnesium oxide InGaMgO) or indium gallium aluminum oxide (InGaAlO). another The material of the first sensing conductor 11 and the second sensing conductor 12 may also include a nano metal material such as a nano silver wire or the like.

The signal wires 110 and 120 include a plurality of first wires 110 connected to the first sensing conductors 11, and a plurality of second wires 120 connected to the second sensing conductors 12 for transmitting the sensing of the touch sensing electrode layer 17. Signal. In one embodiment of the present invention, the material of the signal wires 110, 120 may be silver, molybdenum aluminum molybdenum, gold, copper, but is not limited thereto.

The grounding wires G1 and G2 are located at the periphery of the touch sensing electrode layer 17 and the signal wires 110 and 120 and are electrically insulated from each other. In the present embodiment, in order to simplify the illustration and description, only two ground lines G1 and G2 are exposed, and there is a gap between the ground lines G1 and G2. However, in other embodiments of the present invention, the ground lines may be three or more, and the ground lines are spaced apart from each other by a pitch. According to this configuration, the grounding line G2 located at the outer periphery bears the first ESD protection function, and the grounding line G1 assumes the second ESD protection effect when the grounding line G2 is broken down, for example. In an embodiment of the invention, the material of the grounding wires G1, G2 is selected from the group consisting of silver, molybdenum aluminum molybdenum, gold, copper, and indium tin oxide. Moreover, in another embodiment of the present invention, the ground lines G1 and G2 are different materials. For example, the material of the grounding wire G1 is metal, and the material of the grounding wire G2 is indium tin oxide, and vice versa.

The touch panel 10 can further include a flexible printed circuit board (not shown), pins of the signal wires 110 and 120 (not labeled), and ground pins G1 and G2 (G1A, G1B, and G2A, respectively). , G2B) Electrical connection.

2A is a cross-sectional view of the touch panel 10 taken along the line AA' of FIG. 1 in accordance with an embodiment of the present invention. Referring to FIG. 2A, the grounding lines G1 and G2 are separated from each other by a spacing DG. The first conductive lines 110 are separated from each other by a first spacing D1 from the parallel portions of the grounding lines G1 and G2, and the grounding line G1 is separated. , the minimum distance between G2 and the first wire 110 Then separated by a first predetermined pitch PD1. The first predetermined pitch PD1 is greater than the first pitch D1 to ensure that the ground lines G1, G2 are insulated from the first wire 110. When the touch panel 10 is damaged by ESD, the grounding wires G1 and G2 that are responsible for ESD protection can protect the first wire 110 from ESD attacks. Moreover, the plurality of grounding wires G1 and G2 are beneficial for achieving multiple electrostatic protection of the first wire 110, that is, when one of the grounding wires is damaged by ESD, the other grounding wires can still work normally. In an embodiment of the invention, the grounding lines G1, G2 are between about 15 micrometers and 20 micrometers apart from each other by a DG, and the first spacing D1 between the first conductors 110 is about 15 micrometers and 20 micrometers. Meanwhile, the first predetermined pitch PD1 between the ground lines G1, G2 and the first wire 110 is between about 20 microns and 60 microns, for example 40 microns.

2B is a cross-sectional view of the touch panel 10 taken along line BB' of FIG. 1 in accordance with an embodiment of the present invention. Referring to FIG. 2B, the grounding lines G1 and G2 are separated from each other by a spacing DG. The parallel portions of the second conductive line 120 and the grounding lines G1 and G2 are separated from each other by a second spacing D2, and the grounding line G1 is separated. The shortest distance between G2 and the second wire 120 is separated by a second predetermined pitch PD2. The second predetermined pitch PD2 is greater than the second pitch D2 to ensure that the ground lines G1, G2 are insulated from the second wire 120. When the touch panel 10 is damaged by ESD, the grounding wires G1 and G2 that are responsible for ESD protection can protect the second wire 120 from ESD attacks. Moreover, the plurality of grounding wires G1 and G2 are beneficial for achieving multiple electrostatic protection of the second wire 120, that is, when one of the grounding wires is damaged by ESD, the other grounding wires can still work normally. In an embodiment of the invention, the second spacing D2 between the second wires 120 is between about 15 microns and 20 microns, and the second predetermined spacing PD2 between the ground lines G1, G2 and the second wires 120 is about Between 20 microns and 60 microns, such as 40 microns.

FIG. 3 is a partial cross-sectional view of the touch panel 32 in accordance with an embodiment of the present invention. The components and structures of the touch panel 32 are similar to those of the touch panel 10 shown in FIG. 1 , but the touch panel 32 further includes a shielding layer 34 . Referring now to FIG. 3, the shielding layer 34 is located on the substrate 16. The first conductive line 110, the second conductive line (not shown), and the grounding lines G1 and G2 are formed on the shielding layer. 34. The shielding layer 34 is usually made of an opaque material to shield components outside the touch area 20, such as the first wire 110, the second wire (not shown), and the ground lines G1, G2. In an embodiment of the invention, the material of the masking layer 34 may be selected from the group consisting of a black photoresist material, a black resin, a black ink, a low reflectivity film, or the like having other colors.

In an embodiment of the invention, the touch panel 32 further includes a protective layer (not shown). The protective layer covers the touch sensing electrode layer 17, the first wire 110, the second wire 120, and the ground lines G1, G2 in a whole layer. In an embodiment of the invention, the protective layer is made of a transparent material. The protective layer material may include an inorganic material such as silicon nitride, silicon oxide, and silicon oxynitride, or may be an organic material such as an acrylic resin or the like. Suitable materials, but the invention is not limited thereto.

4 is a schematic diagram of a touch panel 40 in accordance with an embodiment of the present invention. Referring to FIG. 4 , the components and structures of the touch panel 40 are similar to those of the touch panel 10 shown in FIG. 1 , but the touch panel 40 further includes a signal shielding line 18 . The signal shielding line 18 is located in the peripheral region 30 of the substrate 16 and is disposed between the first wire 110 and the second wire 120 to separate the plurality of first wires 110 and the plurality of second wires 120, thereby avoiding The problem that signals between the first wire 110 and the second wire 120 cross each other.

FIG. 5 is a schematic diagram of a touch panel 50 according to an embodiment of the invention. Referring to FIG. 5 , the components and structures of the touch panel 50 are similar to those of the touch panel 10 shown in FIG. 1 , but the touch panel 50 includes only one ground line G . The ground line G is located in the peripheral region 30 and includes one or more non-conductive regions 58. The non-conductive region 58 in the grounding line G causes the grounding wire G to have a plurality of grounding paths, so that when one of the paths is damaged by ESD, the remaining paths can still act to protect the first wire 110 and the second wire 120 from ESD. attack. In addition, the touch panel 50 is only included A grounding wire G is beneficial to achieve a narrow bezel design.

Figure 6 is a schematic illustration of the construction of a ground line G in accordance with an embodiment of the present invention. Referring to FIG. 6, the one or more non-conductive regions 58 in the ground line G include a continuous non-conductive block 581. In one embodiment of the invention, the continuous non-conductive block 581 can be formed by laser etching in the ground line G process.

Figure 7 is a schematic illustration of the construction of a ground line G in accordance with an embodiment of the present invention. Referring to FIG. 7, the one or more non-conductive regions 58 in the ground line G include one or more discontinuous non-conductive blocks 582. In one embodiment of the invention, the discontinuous non-conductive block 582 can be formed by laser etching in the ground line G process.

FIG. 8 is a partial cross-sectional view of a touch panel 80 in accordance with an embodiment of the present invention. The components and structures of the touch panel 80 are similar to those of the touch panel 10 shown in FIG. 1 . The grounding structure of the touch panel 80 is different from the ground lines G1 and G2 of the touch panel 10 .

Referring to FIG. 8, the grounding wires 831 and 832 are located within the peripheral region of the substrate 16, and are disposed around the first wire 110 and the second wire (not shown). The ground lines 831 and 832 partially overlap each other and are electrically insulated from each other by an insulating block 84. According to this configuration, the grounding line 832 located at the outer periphery bears the first ESD protection function, and the grounding line 831 of the inner circumference bears the second ESD protection effect when the grounding line 832 is broken, for example. Moreover, the grounding lines 831 and 832 partially overlap each other, so that the area of the peripheral area can be saved, which is advantageous for achieving a narrow bezel design. In one embodiment of the present invention, the touch panel 80 only exposes two ground lines. However, in actual design requirements, the touch panel may be configured with a plurality of ground lines, and the plurality of ground lines may partially overlap each other. The materials of the grounding wires 831 and 832 are selected from one of silver, molybdenum aluminum molybdenum, gold, copper, and indium tin oxide. In another embodiment of the present invention, the materials of the grounding wires 831 and 832 are different. For example, the grounding wire 831 is made of metal, and the grounding wire 832 is made of indium tin oxide.

Insulation block 84 electrically insulates ground lines 831 and 832. In an embodiment of the invention, the insulating block 84 is formed of a polyester film or an inorganic material, for example, one selected from the group consisting of ruthenium, osmium oxide, and ruthenium nitride.

The first wires 110 are located within a peripheral region of the substrate 16 and are spaced apart from each other by a predetermined distance from the ground wires 831. In one embodiment of the invention, the predetermined distance is between about 20 microns and 60 microns, such as 40 microns.

Through the above embodiments of the present invention, when the touch panel is attacked by ESD, the ground wire that is responsible for ESD protection can protect the first and second wires from ESD attacks. Moreover, in the embodiment of the plurality of grounding lines, the grounding lines are beneficial to achieve multiple electrostatic protection of the first and second wires, that is, when one of the grounding wires is damaged by ESD, the other grounding wires are still It works fine. In addition, in embodiments of the plurality of ground lines, the ground lines may partially overlap each other and be electrically insulated from each other by an insulating block. Such a configuration may reduce the area of the peripheral area and facilitate the narrow bezel design. In addition, in the embodiment of the single grounding wire, the area of the surrounding area can also be reduced to facilitate the design of the narrow bezel. The touch panel further includes a signal shielding line to avoid crosstalk between the first wire and the second wire.

The technical content and the technical features of the present disclosure have been disclosed as above, but those skilled in the art should understand that the teachings and disclosures of the present disclosure are disclosed without departing from the spirit and scope of the disclosure as defined by the appended claims. Can be used for various substitutions and modifications. For example, many of the elements disclosed above may be implemented in different structures or in other structures having the same function, or a combination of the two.

Further, the scope of the present invention is not limited to the apparatus, elements or structures of the specific embodiments disclosed above. It should be understood by those of ordinary skill in the art that, based on the teachings and disclosures of the present disclosure, the device, component or structure, whether present or future developers, The example revealer performs substantially the same function in substantially the same manner, and achieves substantially the same result, and can also be used in the present disclosure. Therefore, the following patent claims are intended to cover such devices, elements or structures.

10‧‧‧Touch panel

11‧‧‧First sensing conductor

12‧‧‧Second sensing conductor

15‧‧‧Bridge

16‧‧‧ glass substrate

17‧‧‧Touch sensing electrode layer

20‧‧‧ touch area

30‧‧‧The surrounding area

110‧‧‧First wire

120‧‧‧second wire

G1‧‧‧ grounding wire

G2‧‧‧ grounding wire

G1A‧‧‧ pin

G1B‧‧‧ pin

G2A‧‧‧ pin

G2B‧‧‧ pin

Claims (19)

A touch panel includes: a substrate divided into a touch area and a peripheral area surrounding the touch area; a touch sensing electrode layer located in the touch area and a part of the peripheral area of the substrate; a signal line is disposed in a peripheral area of the substrate and electrically connected to the touch sensing electrode layer; and a plurality of ground lines are disposed on the periphery of the touch sensing electrode layer and the plurality of signal wires and electrically connected to each other Insulation, wherein the touch sensing electrode layer comprises a first sensing conductor arranged in a first direction, the plurality of signal wires comprising a plurality of first wires connected to the first sensing conductor, and the plurality of first wires and The parallel portions of the grounding lines are separated from each other by a first spacing, and wherein the minimum distance between the plurality of grounding wires and the plurality of first wires is separated by a first predetermined spacing, and the first predetermined spacing is Greater than the first spacing. The touch panel of claim 1, wherein the first predetermined pitch is between 20 micrometers and 60 micrometers. The touch panel of claim 1, wherein the touch sensing electrode layer comprises a second sensing conductor arranged in a second direction, the second direction intersecting the first direction, and the first sensing conductor and the first The two sensing conductors are electrically insulated, and wherein the plurality of signal wires comprise a plurality of second wires connected to the second sensing conductor, wherein the plurality of second wires and the grounding wires are parallel to each other The second pitch is spaced apart, and wherein the shortest distance between the plurality of ground lines and the plurality of second wires is separated by a second predetermined pitch, and the second predetermined pitch is greater than the second pitch. The touch panel of claim 3, wherein the second predetermined pitch is between 20 micrometers and 60 micrometers. The touch panel of claim 3, further comprising a signal shielding line disposed in a peripheral area of the substrate and disposed between the plurality of first wires and the plurality of second wires to separate The plurality of first wires and the plurality of second wires. The touch panel of claim 1, wherein an insulating block is disposed between each adjacent two ground lines of the plurality of ground lines. The touch panel of claim 1, wherein the material of the plurality of grounding wires is selected from the group consisting of silver, molybdenum aluminum molybdenum, gold, copper, and indium tin oxide. The touch panel of claim 7, wherein one of the plurality of ground lines and the other ground line are formed of different materials. The touch panel of claim 1, further comprising: a shielding layer located in a peripheral area of the substrate, wherein the plurality of signal wires and the plurality of ground lines are formed on the shielding layer. A touch panel includes: a substrate divided into a touch area and a peripheral area surrounding the touch area; a touch sensing electrode layer is disposed in the touch area and a portion of the peripheral area of the substrate; a plurality of signal wires are disposed in the peripheral region of the substrate, and are electrically connected to the touch sensing electrode layer; and a ground A line, located in the peripheral region and comprising one or more non-conductive regions. The touch panel of claim 10, wherein the non-conductive region comprises a continuous non-conductive block. The touch panel of claim 10, wherein the non-conductive region comprises a plurality of discontinuous non-conductive blocks. The touch panel of claim 10, wherein the touch sensing electrode layer comprises a first sensing conductor arranged along a first direction, the plurality of signal wires comprising a plurality of first wires connected to the first sensing conductor, And the parallel portions of the plurality of first wires and the ground wires are separated from each other by a first spacing, and wherein the shortest distance between the ground wires and the plurality of first wires is separated by a first predetermined interval. And the first predetermined spacing is greater than the first spacing. The touch panel of claim 13, wherein the first predetermined pitch is between 20 microns and 60 microns. The touch panel of claim 13, wherein the touch sensing electrode layer comprises a second sensing conductor arranged in a second direction, the second direction intersecting the first direction and the first sensing conductor and the first The two sensing conductors are electrically insulated, and wherein the plurality of signal wires comprise a plurality of second wires connected to the second sensing conductor, wherein the plurality of second wires and the grounding wires are parallel to each other The second pitch is spaced apart, and wherein the shortest distance between the ground line and the plurality of second wires is separated by a second predetermined pitch, and the second predetermined pitch is greater than the second pitch. The touch panel of claim 15, wherein the second predetermined pitch is between 20 microns and 60 microns. The touch panel of claim 15 further includes a signal shielding line disposed in a peripheral region of the substrate and disposed between the plurality of first wires and the plurality of second wires to separate The plurality of first wires and the plurality of second wires. The touch panel of claim 10, further comprising: a shielding layer located in a peripheral region of the substrate, and the plurality of signal wires and the grounding wire are formed on the shielding layer. The touch panel of claim 10, wherein the material of the grounding wire is selected from the group consisting of silver, molybdenum aluminum molybdenum, gold, copper, and indium tin oxide.