JP5133449B1 - Transparent touch panel - Google Patents

Abstract

Provided is a transparent touch panel in which the strength of a chemically strengthened glass substrate does not deteriorate even when a large number of lead lines are wired in a wiring region of the chemically strengthened glass substrate at high density.
An insulating layer made of a synthetic resin is formed in the planar wiring region of a glass substrate on which a plurality of lead lines are wired, and a conductive thin film formed by sputtering on the insulating layer is subjected to a photolithography method. Patterning to form a plurality of lead lines.
[Selection] Figure 1

Description

  The present invention relates to a transparent touch panel in which a lead wire for leading a transparent sensor electrode to the outside is provided on a chemically strengthened glass substrate, and more specifically, the lead wire is formed by patterning from a thin film formed by sputtering. It relates to a transparent touch panel.

  A touch panel that performs an input operation using the display of the display device as an indicator forms a transparent sensor electrode in the input operation area so that the display of the display device arranged inside the device can be seen through the input operation area, and the input operation A glass substrate is used as an insulating substrate for forming a transparent sensor electrode in the region. In addition, this glass substrate is a chemically strengthened glass substrate in which the input operation area is exposed along the surface of the device and may be damaged by receiving external force, so that the surface and the back surface are ion-exchanged to strengthen the stress. .

  FIGS. 7 and 8 illustrate a projected transparent capacitive touch panel 100 described in Patent Document 1, and an input operation region 102 a set on the surface of the chemically strengthened glass substrate 101 has A plurality of X-side transparent sensor electrodes 103x along the X direction and a plurality of Y-side transparent sensor electrodes 103y along the Y direction are formed to intersect each other.

  Each of the transparent sensor electrodes 103x and 103y is formed of a transparent conductive material in a band shape having a continuous rhomboid surface, and a connecting electrode 105 that crosses the X-side transparent sensor electrode 103x through the insulating coat 104 intersects at a portion where the two intersect. The diamond-shaped surfaces of the Y-side transparent sensor electrode 103y that are interrupted at the portion are electrically connected, whereby the transparent sensor electrodes 103x and 103y are wired so as to cross each other in the orthogonal direction while being insulated from each other in the input operation region 102a. .

  One side or both sides of each of the transparent sensor electrodes 103x, y are respectively connected to lead wires 106 wired to the wiring region 102b around the input operation region 102a, and external connection portions provided in a part of the wiring region 102b. It is pulled out to 107 and is electrically connected to a detection circuit for detecting the input operation position via the external connection unit 107.

  As shown in FIG. 7, the entire surface of the chemically tempered glass substrate 101 on which the transparent sensor electrodes 103x and 103y, the lead lines 106, etc. are formed is covered with a transparent top coat layer 108 made of a transparent insulating material. In addition, the insulating light shielding layer 109 is printed on the back side where the wiring region 102b is formed. Since the lead wire 106 is formed of a transparent conductive material, it cannot be visually observed. However, a transparent touch panel in which the insulating light shielding layer 109 is formed on the lead wire 106 on the surface side where input operation is performed and covers the lead wire 106 is also disclosed in Patent Document 1. It is described as another example.

  In the transparent sensor electrodes 103x and 103y that the input operation body such as a finger approaches, the stray capacitance increases. Therefore, a rectangular pulse-shaped position detection signal is output from the detection circuit to each transparent sensor electrode 103x and 103y, and the stray capacitance increases. The input operation position to the input operation area 102a is detected from the arrangement position of each of the transparent sensor electrodes 103x and 103y that output the position detection signal whose waveform is distorted by the above.

JP 2011-192124 A

  As described above, the chemically strengthened glass substrate 101 used for the transparent touch panel 100 ion-exchanges sodium ions in the surface layer and the back layer of the glass substrate to potassium ions having a large ion radius so as not to be damaged by an external impact. Thus, a compressive stress layer is generated on the surface layer and the back layer. Since the tensile strength of glass is much smaller than the compressive strength, chemically strengthened glass has a compressive stress layer on its surface in advance, so that it does not chemically strengthen against external forces. About 5 times stronger.

  On the other hand, in order to detect the input operation position with high resolution, it is necessary to arrange a large number of transparent sensor electrodes 103x and 103y in the input operation region 102a, and a large number of lead lines 106 connected to the transparent sensor electrodes 103x and 103y are provided. Therefore, it is necessary to perform wiring at a high density in the limited wiring area 102b around the input operation area 102a. Therefore, there is a limit to wiring by conventional printing, and a conductive material for forming the lead line 106 is formed on the surface of the chemically strengthened glass substrate 101 by sputtering, and each pattern is removed by photolithography to remove unnecessary portions. A lead line 106 is formed.

  At the time of film formation on the chemically strengthened glass substrate 101 by sputtering, extra atoms are pushed into the lattice of the film because the clusters, which are the conductive materials of the lead wires 106, are driven into the film formation on the surface of the glass substrate 101 at a high speed. Even if the difference in thermal expansion coefficient between the glass substrate and the conductive material is taken into account, an internal stress is generated in the direction of expanding the film along the surface, and the tensile stress is applied to the surface of the chemically strengthened glass substrate 101 from the film formation. Works. As a result, the compressive stress generated in the surface layer of the chemically tempered glass substrate 101 is offset by the sputtering process of forming a conductive material on the surface, and the effect cannot be sufficiently obtained despite the chemical strengthening. As a result, there is a problem that the structure is easily damaged by external force.

  The present invention has been made in consideration of such conventional problems, and even if a large number of lead lines are wired in a wiring region of a chemically strengthened glass substrate at high density using sputtering and photolithography, An object is to provide a transparent touch panel in which the strength of the chemically strengthened glass substrate does not deteriorate.

In order to achieve the above object, a transparent touch panel according to claim 1 includes a glass substrate whose plane side is chemically strengthened, and a plurality of transparent sensor electrodes formed to be insulated from each other in the input operation area on the plane of the glass substrate, A plurality of lead wires wired around the input operation area on the flat surface of the glass substrate so that each of the plurality of transparent sensor electrodes is pulled out to the external connection portion, and output from each transparent sensor electrode via the external connection portion from the electrical signal, a transparent touch panel for detecting an input operation of the input operation area, the wiring region of the plane of the glass substrate having a plurality of lead lines are wired, Ri Do a synthetic resin, the input-operation areas first forming an insulating layer formed of an insulating shielding layer for shielding the periphery, on the first insulating layer, further, after forming the second insulating layer, sputtering on the second insulating layer The deposited conductive thin film was patterned by photolithography, and forming a plurality of lead lines.

The first insulating layer and the second insulating layer can be formed in the wiring region by a method other than sputtering, and the plurality of lead lines are formed from a conductive thin film formed by sputtering on the second insulating layer . The tensile stress generated in the conductive thin film during sputtering acts on the surface of the second insulating layer and is not transmitted to the surface of the chemically strengthened glass substrate in the wiring region.

  Since the periphery of the glass substrate is fixed to a case or the like, when an external force is applied in the input operation region near the center, a large bending stress is generated in the wiring region near the fixed end. However, since the plane of the glass substrate in the wiring region is not subjected to tensile stress due to sputtering and is in a chemically strengthened state, the glass substrate is not easily damaged even when subjected to external force.

Since the insulating light-shielding layer that shields light other than the input operation area is the first insulating layer , there is no need to separately form an insulating layer.

The transparent touch panel according to claim 2 , wherein the plurality of transparent sensor electrodes includes a plurality of X-side transparent sensor electrodes and a plurality of Y-side transparent sensor electrodes that are orthogonal to each other in the input operation region. An insulating coat that insulates between the X-side transparent sensor electrode and the Y-side transparent sensor electrode at each intersection of the sensor electrodes and the second insulating layer in the wiring region are formed in the same printing process using an insulating ink. To do.

The second insulating layer can be formed at the same time in the insulating coating printing process for insulating the X-side transparent sensor electrode and the Y-side transparent sensor electrode at the intersection.

The transparent touch panel of claim 3 is characterized in that the transparent sensor electrode is made of ITO and the lead wire is made of a conductive material containing molybdenum.

  Even when molybdenum, which is a hard metal, is formed by sputtering, tensile stress does not act on the surface of the glass substrate.

  According to the first aspect of the present invention, the strength of the chemically strengthened glass substrate does not deteriorate even if the lead wires wired in the wiring region on the plane of the glass substrate are wired at high density using the sputtering method.

Further, since the first insulating layer an insulating shielding layer, in the step of forming the insulating shielding layer can be formed first insulating layer to be interposed between the lead wire and the glass substrate.

According to the invention of claim 2 , the second insulating layer interposed between the lead wire and the glass substrate can be formed in the printing process of the insulating coat that insulates between the X-side transparent sensor electrode and the Y-side transparent sensor electrode.

According to the third aspect of the present invention, the strength of the glass substrate does not deteriorate even if the lead wire is formed of a conductive material containing molybdenum, which is a hard metal. The lead wire can be formed of a conductive material containing molybdenum having excellent electrical contact characteristics with respect to indium oxide constituting the transparent sensor electrode.

(A) is a top view of the transparent touch panel 1 which concerns on one embodiment of this invention, (b) is sectional drawing along the AA line in the figure of (a). (A) which shows the 1st process in which the insulation light shielding layer 8 was formed is a top view, (b) is sectional drawing cut | disconnected in the position along the AA. (A) which shows the 2nd process which formed the connection electrode 6 in the input operation area | region 2a is a top view, (b) is sectional drawing cut | disconnected in the position along the AA. (A) which shows the 3rd process of covering the connection electrode 6 and the insulation light shielding layer 8 with the insulation coat 7, (a) is a top view, (b) is sectional drawing cut | disconnected in the position along the AA. 4A shows a fourth step of wiring the lead wire 5 to the wiring region 2b. FIG. 5B is a plan view, and FIG. 5B is a cross-sectional view taken along a line AA in FIG. is there. It is sectional drawing cut | disconnected in the position along the AA line which shows the 5th process which forms the transparent sensor electrodes 3 and 4 in the input operation area | region 2a. It is a top view of the conventional transparent touch panel 100. FIG. 2 is a longitudinal sectional view of a transparent touch panel 100. FIG.

  The transparent touch panel 1 according to the first embodiment of the present invention will be described below with reference to FIGS. The transparent touch panel 1 is attached to a case as an input device for an electronic device such as a mobile phone, with the upper side in FIG. 1B facing the inner side of the electronic device, and the lower side in the figure is outside the case. Although the input operation is performed, the upper surface of the glass substrate shown in FIG.

  The transparent touch panel 1 uses a transparent glass substrate 2 as an insulating substrate on which a sensor electrode is formed in order to enable an input operation while viewing a display device arranged inside the device. Since the glass substrate 2 is disposed along the surface of the case, it is immersed in a potassium nitrate melt at about 380 ° C. so that it does not break even when subjected to external force, and is replaced with sodium ions (Na +) on the front and back layers. Chemical strengthening to incorporate ions (K +). Since the ionic radius of the potassium ion (K +) is larger than the sodium ion (Na +), compressive stress is generated in the front and back layers of the chemically strengthened glass substrate 2. In general, the glass substrate 2 has a much lower tensile strength than the compressive strength, and a tensile stress is generated on the front and back surfaces and breaks. Therefore, by generating a compressive stress on the front and back layers in advance, The strength is about 5 times the strength before strengthening.

  As shown in FIG. 1, the plane of the glass substrate 2 is in a matrix form along the XY direction in which a large number of X-side transparent sensor electrodes 3, 3... And Y-side transparent sensor electrodes 4, 4,. The input operation area 2a to be formed and the wiring area 2b around which many lead lines 5, 5,.

  Each of the plurality of X-side transparent sensor electrodes 3 formed in the input operation region 2a is electrically connected by a narrow strip-shaped connecting electrode 6 between the rhombus X-pattern bodies separated by the intersecting region intersecting the Y-side transparent sensor electrode 4. They are connected and wired in a strip shape along the Y direction. Each of the plurality of Y-side transparent sensor electrodes 4 formed in the input operation area 2a has a narrow width in an intersecting area where the rhombus Y-pattern body substantially the same as the X-pattern body intersects the X-side transparent sensor electrode 3. Wiring is continued along the X direction through the connected pattern. The connection pattern of the Y-side transparent sensor electrode 4 straddles the connection electrode 6 through an insulating coat 7 formed on the connection electrode 6, thereby crossing the X-side transparent sensor electrode 3 and the Y-side transparent sensor at each intersection region. The electrodes 4 are insulated from each other and wired.

  The X-side transparent sensor electrode 3 and the Y-side transparent sensor electrode 4 can be formed of an arbitrary transparent conductive material that can be formed on the glass substrate 2 by patterning from a thin film. (Indium Tin Oxide). The insulating coat 7 uses an insulating material such as silica (SiO 2).

  In the wiring area 2b around the input operation area 2a, an insulating light-shielding layer 8 made of a light-shielding insulating resin is printed over the entire area. The insulating light-shielding layer 8 shields the periphery of the input operation area 2a so that the operator can make the input operation area 2a stand out and the portions other than the inner display screen are not noticeable. If it is, it can be arbitrarily colored, but here it is black. Furthermore, in the present invention, as described below, the base of the lead wire 5 formed in the wiring region 2b through the sputtering process also acts to prevent the strength deterioration of the wiring region 2b of the glass substrate 2.

  In this embodiment, since the insulating light-shielding layer 8 is formed of a material in which carbon, chromium, or the like is contained in a photocurable insulating resin, when a plurality of lead lines 5 are wired on the insulating light-shielding layer 8, the lead-out layer Insufficient insulation between the lines 5 is not obtained, and the insulating coat 7 is formed also on the insulating light-shielding layer 8 in the wiring region 2b in the same process of printing the insulating coat 7 in the intersection region.

  A plurality of lead wires 5 wired on the insulating coat 7 in the wiring area 2a are connected to both sides of each X-side transparent sensor electrode 3 and each Y-side transparent sensor electrode 4, respectively, and are insulated from each other so as to be external to the wiring area 2a. It is pulled out to the connection part 9.

  All the lead wires 5 are arranged and wired in the external connection portion 9, are connected to corresponding electrodes of the flexible wiring board through an anisotropic conductive adhesive or the like, and are transparent to each X side via the external connection portion 9. Both sides of the sensor electrode 3 and each Y-side transparent sensor electrode 4 are connected to a detection circuit (not shown) that detects an input operation to the input operation area 2a.

  Accordingly, the total number of lead lines 5 is twice that of the sensor electrodes 3 and 4 formed in the input operation area 2a, and all the lead lines 5 need to be insulated from each other in the limited wiring area 2a. Therefore, after forming a film on the insulating coat 7 by sputtering, patterning is performed by a photolithography method and wiring is performed at a high density.

  The lead wire 5 has MAM (Mo (molybdenum) / Al) because ITO constituting the transparent sensor electrodes 3 and 4 to be connected is excellent in physical, chemical and electrical contact characteristics and has low electrical resistivity. A composite material having a three-layer structure in which (aluminum) and Mo) are laminated is used. Therefore, in the film formation process by sputtering, a thin film is formed by dividing into three layers of Mo, Al, and Mo. In this sputtering process, clusters (sputtering materials) are driven into the film at high speed, so that the film is formed. Extra atoms are pushed into the lattice and the coating expands along the substrate surface. As a result, the substrate is subjected to tensile stress from the coating formed along the surface.

  In particular, Mo directly formed on the surface of the base material is a hard metal, and therefore a large tensile stress is generated on the surface of the base material in the Mo film forming process by sputtering. Here, when the lead wire 5 is formed directly on the plane of the glass substrate 2 as in the prior art, the plane of the glass substrate 2 that has been chemically strengthened and has generated the compressive stress is canceled by the tensile stress and is damaged. It will be easy to do. On the other hand, in the present embodiment, a MAM thin film is formed on the plane of the glass substrate 2 through the insulating light-shielding layer 8 and the insulating coat 7 formed of insulating synthetic resin. Does not receive tensile stress and maintains chemically strengthened strength.

  The entire plane side of the glass substrate 2 on which the transparent sensor electrodes 3 and 4 and the lead wires 5 are formed is covered with a top coat 10 made of a transparent insulating resin, as shown in FIG. The lead wire 5 is protected.

  The transparent touch panel 1 configured as described above has a transparent sensor electrode 3 that the input operation body approaches via the glass substrate 2 when the input operation body such as a finger approaches the input operation area 2a from below in FIG. 4 increases, the X-side transparent sensor electrode 3 and the Y-side transparent sensor electrode 4 whose capacitance changes are detected respectively, and the arrangement of the detection electrodes 3 and 4 on the input operation area 2a is detected. The input operation position is detected in the XY directions from the installation position.

Hereafter, the manufacturing process of the above-mentioned transparent touch panel 1 is demonstrated. First, as shown in FIG. 2A , an insulating light shielding layer 8 as a first insulating layer is printed and formed on the entire wiring region 2b on the plane of the chemically strengthened glass substrate 2. Since the formation of the insulating light shielding layer 8 does not use a film forming process by sputtering, the strength of the wiring region 2b does not deteriorate.

  Subsequently, an ITO thin film is formed on the entire plane of the glass substrate 2 including the insulating light-shielding layer 8 by sputtering. In this sputtering process, an ITO thin film is formed directly on the input operation region 2a on the plane of the glass substrate 2, but since ITO is softer than Mo constituting MAM, a large tensile stress is generated in the film forming process. Not receive.

  Further, the glass substrate 2 is attached with its periphery fixed to the case, and when the input operation area 2a facing outward receives an unintended external force, a larger bending moment is generated in the wiring area 2b near the fixed end. A large tensile stress that breaks the glass substrate 2 does not act on the plane of the input operation area 2a. Therefore, even if the film is formed by sputtering in the input operation region 2a, the strength of the entire glass substrate 2 is not impaired.

  The ITO thin film formed on the entire plane of the glass substrate 2 is removed by etching using the photolithography method, leaving portions that will become the connecting electrodes 6 in the respective intersecting regions, as shown in FIGS. As described above, the elongated connection electrode 6 is formed along the Y direction in each intersection region of the input operation region 2a.

Subsequently, as shown in FIGS. 4A and 4B, the input operation region 2a crosses over each connection electrode 6, and the wiring region 2b covers the entire insulating light-shielding layer 8 as the first insulating layer. An insulating coat 7 made of SiO2 is formed by printing so as to be the second insulating layer .

  Thereafter, sputtering using Mo, Al, and Mo as the sputtering material was repeated to form a thin film having a three-layer structure of MAM on the entire plane of the glass substrate 2 shown in FIGS. 4 (a) and 4 (b). (A) As shown in (b), using the photolithography method, the pattern of the lead-out line 5 from the portions on both sides of the X-side transparent sensor electrode 3 and the Y-side transparent sensor electrode 4 to the external connection portion 9 is left. And removed. In the sputtering process for forming the MAM thin film in the wiring region 2b, the film is formed on the plane of the glass substrate 2 with the insulating light-shielding layer 8 and the insulating coat 7 interposed therebetween, so that no tensile stress acts on the plane of the glass substrate 2. . Further, in the same sputtering process, the input operation region 2a is temporarily subjected to tensile stress, but since all the MAM thin film on the input operation region 2a is removed, the tensile stress does not act similarly.

  Subsequently, again, an ITO thin film is formed on the entire plane of the glass substrate 2 by sputtering. As shown in FIG. 6, the X-side transparent sensor electrode 3 and the Y-side transparent sensor electrode 4 are used by photolithography. And the ITO thin film is removed leaving the lead wire 5 portion. By patterning using this photolithography method, the rhombus X pattern bodies formed in the input operation region 2a are electrically connected by the connecting electrode 6, and the strip-shaped X-side transparent sensor electrode 3 is wired along the Y direction. . Further, the Y-side transparent sensor electrode 4 is formed on the insulating coat 7 in which a narrow connection pattern straddles the connection electrode 6 and is formed in the intersecting region. The side transparent sensor electrodes 4 are wired while being insulated from each other. The ITO thin film forming each X-side transparent sensor electrode 3 and each Y-side transparent sensor electrode 4 is also left on the lead-out line 5 on both sides thereof, thereby being electrically connected to the lead-out line 5.

  Even in the above-described steps, ITO is directly formed on the input operation region 2a of the glass substrate 2 by sputtering, so that it receives tensile stress, but for the same reason as the step of forming a film by sputtering to form the connection electrode 6. The strength against the external force of the entire glass substrate 2 is not impaired.

  Then, after connecting a flexible wiring board to the external connection part 9, the whole plane of the glass substrate 2 is covered with the topcoat 10 using a roll coater etc., and the transparent touch panel 1 is manufactured.

  In the above-described embodiment, the transparent touch panel 1 that performs an input operation from the opposite side of the glass substrate 2 with the plane on which the X-side transparent sensor electrode 3, the Y-side transparent sensor electrode 4 and the lead-out line 5 are formed has been described. An input operation may be performed from above the coat layer.

  Moreover, as long as the lead wire 5 is formed in the wiring region 2b of the glass substrate 2 via an insulating layer, the shape of the sensor electrodes 3 and 4 and the formation process thereof are arbitrary. The transparent touch panel which detects input operation not only by a system but by the resistance system which made the sensor electrode the resistance film which made the resistance value per unit length uniform may be sufficient.

  In addition, the insulating layer formed between the plane of the glass substrate 2 in the wiring region 2b and the lead wire 5 is not limited to the above-described insulating coating 7 and insulating light shielding layer 8 as long as it is not formed by sputtering. You may form in a process.

  It is suitable for transparent touch panels in which lead lines are wired at high density around the input operation area of the glass substrate.

DESCRIPTION OF SYMBOLS 1 Transparent touch panel 2 Glass substrate 2a Input operation area 2b Wiring area 3 X side transparent sensor electrode (transparent sensor electrode)
4 Y side transparent sensor electrode (transparent sensor electrode)
5 Leader line 7 Insulation coat (insulation layer)
8 Insulating light shielding layer (insulating layer)
9 External connections

Claims (3)

A glass substrate whose plane side is chemically strengthened;
A plurality of transparent sensor electrodes formed to be insulated from each other in the planar input operation region of the glass substrate;
A plurality of lead lines wired around the input operation area on the flat surface of the glass substrate so as to draw out each of the plurality of transparent sensor electrodes to the external connection part,
A transparent touch panel that detects an input operation to an input operation area from an electrical signal output from each transparent sensor electrode via an external connection unit,
In the wiring region of the plane of the glass substrate having a plurality of lead lines are wired, Ri Do a synthetic resin, forming a first insulating layer formed of an insulating shielding layer for shielding the periphery of the input-operation areas,
After further forming a second insulating layer on the first insulating layer,
A transparent touch panel, wherein a plurality of lead lines are formed by patterning a conductive thin film formed by sputtering on a second insulating layer using a photolithography method. The plurality of transparent sensor electrodes are composed of a plurality of X-side transparent sensor electrodes and a plurality of Y-side transparent sensor electrodes that are orthogonal to each other in the input operation region,
The insulating coat that insulates between the X-side transparent sensor electrode and the Y-side transparent sensor electrode at each intersection of the X-side transparent sensor electrode and the Y-side transparent sensor electrode and the second insulating layer in the wiring region are the same using an insulating ink. The transparent touch panel according to claim 1, wherein the transparent touch panel is formed by a printing process. The transparent touch panel according to claim 1 or 2 , wherein the transparent sensor electrode is made of ITO , and the lead wire is made of a conductive material containing molybdenum.

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