JP2016006573A - Cover glass integrated touch panel sensor substrate and cover glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel suppressing strength degradation in a four-point bending test of ends of a two-face tempered glass substrate having chemically strengthened layers on both sides which is cut even when such a glass substrate is used.SOLUTION: A cover glass integrated touch panel sensor substrate comprises, on one surface of a two-face tempered glass substrate 1 having chemically strengthened layers on both sides, a display area, and a decorative frame formed on an outer periphery of the display area, which are sectioned from each other. An end of the glass substrate 1 is chamfered, and the outer side thereof is covered by a protective material 2 in an arc shape. An expression d=√2f+r-[r-(t/2)]is satisfied where t denotes a thickness of the glass substrate 1, f denotes a distance starting from a chamfer shoulder 3 as an original point to an arc of the protective material orthogonal to a straight line in a thickness direction 45° at an intersection with a chamfered outermost end, r denotes the curvature radius of the protective material, and d denotes a distance starting from the shoulder of the glass substrate as an original point to a chamfered outermost end of the protective material from the centre of the glass substrate in a depth direction.

Description

  The present invention relates to a position input device for a computer, and more particularly to a cover glass-integrated touch panel sensor substrate and a cover glass that are used while being superimposed on a display screen.

  In recent years, a touch panel has been adopted as an operation unit of an electronic device such as a mobile phone or a portable information terminal. There are two types of touch panels: film type and glass type. The film type is lightweight, hard to break, inexpensive to manufacture, and flexible, so it has the merit that it is easy to remove bubbles when bonding with other display devices and cover glass, but the light transmission of the film The rate is low compared to glass, and the positional accuracy of the wiring pattern formed on the film is inferior to that of glass, so the frame area covering the lead-out wiring becomes large and the display area becomes narrow, Due to the difference in smoothness, there is a problem that it looks worse than the glass type. In small products such as smart phones and tablet computers that require high definition and low power consumption, many glass types are used.

  A touch panel sensor used in a mobile phone or the like generally has a frame portion, a lead-out wiring, two layers of transparent electrodes for X and Y directions, an insulating layer between two layers of transparent electrodes on a large glass substrate, After the protective layer on the surface is formed by multiple imposition, it is cut into individual substrates for each piece. The touch panel sensor cut into individual pieces is generally used by being bonded via a cover glass for preventing breakage and a transparent adhesive sheet (OCA) or the like. The cover glass can be formed with a frame portion made of a highly light-shielding material in order to conceal design and peripheral wiring.

The cover glass is a front plate serving as the outermost surface, and aluminosilicate glass containing at least one kind of alkali metal oxide selected from SiO ₂ , Al ₂ O ₃ , Li ₂ O and Na ₂ O is tempered. Is generally used. The glass strengthening treatment includes physical strengthening (air cooling strengthening) that rapidly cools after heating the glass surface to near the softening point and chemical strengthening that replaces alkali ions inside the glass with alkali ions having a larger particle size. A thin plate of 1 mm or less used for a cellular phone is not suitable for physical strengthening because the temperature difference between the surface and the inside is difficult to be applied, and chemical strengthening is generally used.

  The chemical strengthening of glass involves immersing the glass in a molten salt below the glass transition point, and replacing the alkali ions inside the glass with alkali ions having a larger ionic radius, thereby reducing the compressive stress due to the difference in ionic radius. It is a method to generate. By generating compressive stress on the glass surface, the strength of the glass is improved in order to prevent tensile stress from concentrating on the scratches generated on the glass surface.

  Recently, for the purpose of cost reduction, a cover glass integrated touch panel sensor substrate has been developed in which a sensor is formed on one surface of a single glass substrate and the other surface functions as a cover glass (Patent Document 1). .

  As a glass substrate used for the cover glass integrated touch panel sensor substrate as described above, when a two-side tempered glass substrate in which only the front and back surfaces are chemically strengthened is used, the glass substrate is chemically strengthened from the front and back surfaces toward the inner central portion. Therefore, there is a risk of damage during cutting and a decrease in strength. Therefore, as a countermeasure, a six-sided tempered glass substrate in which the cut surface is chemically strengthened after cutting is generally used.

  However, the measures described above are expensive due to the use of a six-sided tempered glass substrate, and because the chemical strengthening is performed after cutting into individual pieces, the process is complicated and productivity is significantly reduced. There is a problem.

JP 2012-226688 A

  Even if a double-sided tempered glass substrate having a chemically strengthened layer on both sides is used, the present invention is capable of scratching in the strength of the edge of the glass substrate after cutting, particularly in a four-point bending test that has been strongly demanded by the market recently. An object is to provide a cover glass-integrated touch panel sensor substrate (hereinafter referred to as a touch panel) and a cover glass in which strength reduction is suppressed even after the test.

The invention of claim 1 according to the present invention is divided into a display region and a decorative frame formed on the outer periphery thereof on one surface of a double-sided tempered glass substrate having a chemically strengthened layer on the front and back sides, and The glass substrate is chamfered at the end and is covered with a protective material on the outside in a circular arc shape with a cover glass integrated touch panel sensor substrate,
The thickness of the glass substrate is t, the distance from the chamfered shoulder to the arc of the protective material orthogonal to the intersection of the 45 ° straight line and the chamfered end is f, the curvature of the protective material When the radius is r and the distance from the center in the thickness direction of the glass substrate to the chamfered outermost edge of the protective material starting from the shoulder of the glass substrate is d, d = √2f + r− [r ² − ( It is a touch panel characterized by satisfying the expression of t / 2) ² ] ^1/2 .

According to the invention of claim 2, when the chamfered outermost end of the glass substrate from the shoulder portion of the glass substrate is j, the width of the outermost end is k, and A = t / 2 + r−d + √2f. J = [A + (− A ² + 2r ² ) ^1/2 ] / 2−r + d, k = 2 {[A + (− A ² + 2r ² ) ^1/2 ] / 2−√2f}. 2. The touch panel according to claim 1, wherein the touch panel is characterized.

  The invention according to claim 3 is the touch panel according to claim 1 or 2, wherein the thickness t of the glass substrate is in a range of 0.3 mm ≦ t ≦ 1.1 mm.

  The invention according to claim 4 is the touch panel according to any one of claims 1 to 3, wherein the radius of curvature of the end chamfer of the glass substrate is infinite.

In the invention of claim 5, the chamfered shape of the protective material is a circle having a center point in the thickness direction of the glass substrate as a base point, and the maximum thickness f ″ of the protective material in the 45 ° direction from the shoulder portion. 5 satisfies the expression f ″ = f + [(− r / √2 + A / 2) ² + (r / √2−A / 2) ² ] ^1/2 . It is a touchscreen as described in.

In the invention of claim 6, the constant α is in the range of 0 ≦ α ≦ 0.2 between the thickness t of the glass substrate and the curvature radius r of the protective material, and r = t / 2 ( The touch panel according to any one of claims 1 to 5, wherein the formula 1 + α) is satisfied.

Further, the invention of claim 7 is laminated on a touch panel sensor substrate in which end portions of a double-sided tempered glass substrate having a chemically strengthened layer on both sides are chamfered and the outside is covered with a protective material in an arc shape. Cover glass for
The thickness of the glass substrate is t, the distance from the chamfered shoulder to the arc of the protective material orthogonal to the intersection of the 45 ° straight line and the chamfered end is f, the curvature of the protective material When the radius is r and the distance from the center in the thickness direction of the glass substrate to the chamfered outermost edge of the protective material starting from the shoulder of the glass substrate is d, d = √2f + r− [r ² − ( It is a cover glass characterized by satisfying the expression of t / 2) ² ] ^1/2 .

  Originally, even when a front and back two-sided tempered glass substrate is used as a glass substrate, which is weak in physical strength such as impact strength, as a cross-sectional end, the chamfered shape of the cross-sectional end of the glass substrate and the protective material covering it By forming the shape so as to satisfy each formula of the invention according to the claims of the present invention, the strength of the edge of the glass substrate after cutting, particularly in the four-point bending test that has been strongly demanded from the market recently, It is possible to provide a touch panel and a cover glass in which strength reduction is suppressed even after a scratch test.

It is a section schematic diagram showing one embodiment concerning a touch panel of the present invention.

  The present invention is divided into a display region and a decorative frame formed on the outer periphery thereof on one surface of a two-sided tempered glass substrate having a chemically strengthened layer on the front and back, and an end of the glass substrate is It is a touch panel that is chamfered and further covered with a protective material in an arc shape. In addition, the present invention is a cover glass for laminating on a touch panel sensor substrate in which the ends of a two-sided tempered glass substrate having a chemically strengthened layer on the front and back are chamfered, and the outer side is covered with a protective material in an arc shape. It is. As a result of intensive studies, the inventors have found that, in the chamfered shape of the cross-sectional end portion of the glass substrate and the shape of the protective material covering it, it is possible to suppress a decrease in end strength by satisfying the relational expression described in the claims. It was.

  Hereinafter, the present invention will be described more specifically based on the drawings.

As shown in FIG. 1, specifically, the thickness of the glass substrate 1 is t, and the protective material is orthogonal at the intersection of a 45 ° straight line in the thickness direction starting from the chamfered shoulder and the chamfered end. The distance from the center of the glass substrate to the chamfered outermost edge from the center in the thickness direction of the glass substrate 1 starting from the shoulder 3 of the glass substrate 1 is d. The touch panel is characterized by satisfying the following formula: d = √2f + r− [r ² − (t / 2) ² ] ^1/2 .

That is, the end of the cross section of the glass substrate 1 having a thickness t is chamfered, and the protective material 2 is applied on the chamfered portion so as to cover it in an arc shape. r ² − (t / 2) ² ] By satisfying the formula of ^1/2 , even if a front and back 2 tempered glass substrate with originally low cross-sectional strength is used, a decrease in strength of the end portion can be suppressed.

Further, when j is the chamfered outermost end of the glass substrate from the shoulder portion of the glass substrate, k is the width of the outermost end, and A = t / 2 + r−d + √2f, j = [A + (− A ² + 2r ² ) ^1/2 ] / 2-r + d, k = 2 {[A + (− A ² + 2r ² ) ^1/2 ] / 2−√2f}, thereby satisfying the cross-sectional edge of the glass substrate The chamfered shape of the portion is trapezoidal, and the maximum thickness f ″ of the protective material in the direction of 45 ° from the shoulder portion can be sufficiently ensured, and a decrease in the strength of the end portion can be suppressed. By making the radius of curvature of the end chamfer of the glass substrate 1 infinite, it is possible to ensure strength against an impact from a direction perpendicular to the glass end surface.

On the other hand, the chamfered shape of the protective material is circular with the center point in the thickness direction of the glass substrate as a base point, and the maximum thickness f ″ of the protective material in the 45 ° direction from the shoulder portion is f ″ = f + [ (-R / √2 +
By satisfying the formula of A / 2) ² + (r / √2−A / 2) ² ] ^1/2 , it is possible to suppress a decrease in the strength of the end portion as described above.

  In addition, the constant α is in the range of 0 ≦ α ≦ 0.2 between the thickness t of the glass substrate 1 and the curvature radius r of the protective material 2 and the equation r = t / 2 (1 + α) is satisfied. Satisfaction can also suppress a decrease in strength of the end portion.

  The thickness t of the glass substrate according to the present invention is preferably in the range of 0.3 mm ≦ t ≦ 1.1 mm. When the thickness t is less than 0.3 mm, handling at the time of processing becomes difficult, leading to a decrease in productivity and a decrease in quality. On the other hand, when the thickness exceeds 1.1 mm, the response sensitivity is lowered, the weight is increased, and the cost is increased.

  The glass substrate 1 that can be used in the present invention needs to have a chemically strengthened layer on both sides. The glass strengthening treatment includes physical strengthening (air cooling strengthening) that rapidly cools after heating the glass surface to near the softening point and chemical strengthening that replaces alkali ions inside the glass with alkali ions having a larger particle size. A thin plate of 1 mm or less used for a cellular phone is not suitable for physical strengthening because the temperature difference between the surface and the inside is difficult to be applied, and chemical strengthening is generally used.

  The chemical strengthening of glass involves immersing the glass in a molten salt below the glass transition point, and replacing the alkali ions inside the glass with alkali ions having a larger ionic radius, thereby reducing the compressive stress due to the difference in ionic radius. It is a method to generate. By generating compressive stress on the glass surface, the strength of the glass is improved in order to prevent tensile stress from concentrating on the scratches generated on the glass surface. The front and back two-sided tempered glass substrate used in the present invention is not particularly limited with respect to its chemical strengthening method.

  As a method for cutting the glass substrate 1 according to the present invention, a break method, a laser cut method, a water jet flow method, or the like can be used. It is also possible to cut the surface provided with the etching resistant film in combination with a method of immersing in the etching solution. In this case, for example, the etching solution is not particularly limited as long as it contains at least hydrofluoric acid, but if necessary, other acids such as hydrochloric acid and various additives such as a surfactant are added. Also good. Moreover, etching temperature is 10 to 80 degreeC normally, Preferably it is 20 to 40 degreeC. Further, the etching time is usually 30 seconds to 30 minutes, preferably 1 minute to 10 minutes. These etching conditions can be appropriately selected according to the material of the glass substrate to be used and the like so that no reactant is precipitated. Before removing the etching resistant film, the outer peripheral edge of the individual substrate is polished, and after removing the protrusions, etching is performed to remove microcracks generated during the cutting and polishing of the individual substrate. be able to.

  In addition, as the protective material 2 used in the present invention, for example, an ionizing radiation curable resin composition can be applied and irradiated with an ionizing radiation such as an electron beam or ultraviolet ray to be cured, and a protective material can be applied. The ionizing radiation curable resin composition contains a radical polymerizable resin and a photopolymerization initiator, and contains a solvent, an antistatic agent, an antiglare agent, and other additives as necessary.

  More specifically, after a glass end surface cut from the composition is applied by a known method, such as a felt coating method, a dipping method, a dispensing method, or a roll coating method, and a solvent that is unnecessary for the protective material is dried. A protective material can be formed by irradiating with ionizing radiation such as an electron beam or ultraviolet ray, curing the material, and further baking. The method for applying the end face is not particularly limited as long as the end face is sufficiently covered in an arc shape. In addition, as conditions to form in the said arc shape, the viscosity of the said composition, solid content ratio, hardening time, etc. are important, It is necessary to adjust suitably with the said composition to be used.

  As the radical polymerizable resin contained in the ionizing radiation curable resin composition for forming the protective material of the present invention, for example, in the presence of a photopolymerization initiator that generates radicals by ultraviolet rays that are one of ionizing radiation, It is a compound having radical polymerizability that is polymerized or crosslinked by irradiation with actinic radiation. For example, it contains at least one ethylenically unsaturated bond in the structural unit, and contains a bifunctional, trifunctional or higher (meth) acrylate monomer or urethane acrylate in addition to a monofunctional vinyl monomer. Or a mixture thereof.

  The display area according to the present invention includes X, Y-axis direction transparent electrodes, jumper wiring, lead-out wiring, insulating protective layers, and the like, and can be formed by, for example, the following method.

  The transparent electrode in the X-axis direction is for detecting the X coordinate. The transparent electrode is formed in the display region using a material having electrical conductivity and transparency. The transparent electrodes are intermittently arranged in a matrix in the X direction and the Y direction, and are electrically connected to jumper wirings adjacent in the X direction. The transparent electrode is made of, for example, ITO (Indium Tin Oxide).

  On the other hand, the transparent electrode in the Y-axis direction is for detecting the Y coordinate and is formed using the same material as the transparent electrode. The transparent electrode extends in the Y direction between the columns of the transparent electrodes aligned in the Y direction, and three-dimensionally intersects with the jumper wiring on the insulating film.

  The jumper wiring is formed using a conductive material, and is arranged intermittently and in a matrix in the display area in the X direction parallel to one side of the display area and in the Y direction orthogonal thereto. The jumper wiring is for connecting transparent electrodes aligned in the X direction.

  The lead-out wiring is formed on the frame area and is electrically connected to the transparent electrodes in the X-axis and Y-axis directions located at the peripheral edge of the display area. The lead wiring is generally formed of a metal material, for example, made of a laminated body of Mo / Al / Mo (molybdenum / aluminum / molybdenum) or the like, and also formed of Au (gold), Ag (silver), Ag alloy, or the like. May be.

  The frame area is formed on the outer periphery of the display area and is generally for concealing the lead-out wiring and the like, and a logo mark and the like are formed.

  Examples of the material for forming the frame region include a photosensitive resin including a photopolymerizable functional group-containing resin or ogomer, a photopolymerization monomer, a photopolymerization initiator, and a colorant having a concealing property (light-shielding property). Compositions can be used.

  Examples of the resin having a photopolymerizable functional group include polycarboxylic acid esters such as polyurethane and polyacrylate, unsaturated polyamide, polycarboxylic acid, polycarboxylic acid (partial) amine salt, polycarboxylic acid ammonium salt, and polycarboxylic acid. Examples thereof include alkylamine salts, polysiloxanes, (meth) acrylic acid and copolymers, and these can be used alone or in admixture of two or more.

  Moreover, as said coloring material, dye, an organic pigment, and an inorganic pigment can be used conveniently. For example, carbon black, titanium black, aniline black, anthraquinone black pigment, and the like can be used, but carbon black is preferred from the viewpoint of cost and light shielding properties.

Moreover, you may use the dispersing agent and surfactant for dispersing a pigment in the said photosensitive resin composition. Surfactants, pigment intermediates, dye intermediates, Solsperse, and the like are used as the dispersant, and have a pigment affinity part having a property of adsorbing to the pigment and a part compatible with the pigment carrier. It functions to adsorb to the pigment and stabilize dispersion in the pigment carrier.

  EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

<Example 1>
A touch panel composed of a display region and a frame region was formed on one surface using a two-sided tempered glass substrate having a thickness of 0.55 mm and whose front and back surfaces were chemically strengthened. Specific description will be given below.

  The outer periphery of the position where the display area of one surface of the glass substrate is formed is printed by a screen printing method using a photosensitive resin composition having carbon black, and then the frame area is cured by irradiation with ultraviolet rays. Formed.

  Next, an ITO film was formed on the entire inner surface of the frame region by a DC magnetron sputtering method using ITO as a transparent conductive material. Next, a novolac positive resist was applied on the entire surface, baked, exposed to a mask, and further developed with an alkaline aqueous solution. Thereafter, etching was performed using oxalic acid, and the positive resist was exposed on the entire surface, and then the positive resist was peeled off with an alkaline aqueous solution to form a transparent electrode serving as a jumper.

  Next, a negative resist was applied and pre-baked by a spin coating method, and then exposed through a patterned mask. Next, development was performed using an alkaline aqueous solution, followed by baking to form an insulating layer having a predetermined pattern.

  Next, a lead-out wiring was formed on the frame area by the following procedure. A Mo layer, an Al layer, and a Mo layer were sequentially laminated in a vacuum by a DC magnetron sputtering method to form a Mo / Al / Mo (molybdenum / aluminum / molybdenum) laminate. Next, a novolac positive resist was spin-coated thereon, prebaked, exposed through a mask patterned with Cr, and further developed using an alkaline aqueous solution. After that, etching is performed with a three-component etching solution composed of a mixed aqueous solution containing phosphoric acid, nitric acid, and acetic acid as main components, and the positive resist is exposed on the entire surface, and then the positive resist is stripped with an alkaline stripping solution composed of an aqueous solution containing silicate. The lead wiring was formed.

  Next, transparent electrodes in the X-axis direction and the Y-axis direction were formed in the display area by the following method. First, an ITO film was formed by DC magnetron sputtering using ITO as a transparent conductive material. Next, a novolac positive resist was applied on the entire surface, baked, masked, and developed with an alkaline aqueous solution. Thereafter, etching was performed using oxalic acid, and the positive resist was exposed on the entire surface, and then the positive resist was peeled off with an alkaline aqueous solution to form transparent electrodes in the X-axis direction and the Y-axis direction.

  Next, a protective layer forming composition made of a photosensitive resin was applied to the entire surface of the frame region and the display region by spin coating, pre-baked, exposed and cured to form a protective layer.

  Next, the two-sided tempered glass substrate on which the frame region and the display region were formed was cut around the outer periphery of the frame region to produce a touch panel. The cutting method is described below.

A slimming treatment was performed by a chemical etching method so that the chamfered shape of the glass substrate was a trapezoid as shown in FIG. Etching was performed by laminating a masking film having an etching resistance property on both surfaces of the glass substrate. Then, it cut by scribe cutting, the cut end part was grind-processed, the shape was adjusted, and the chamfering of the said glass substrate was complete | finished. The trapezoid obtained was j = 97 μm and k = 174 μm.

  Next, the edge of the glass substrate that has been chamfered is immersed in a photosensitive resin composition for forming a protective material, then pulled up, cured by irradiating with ultraviolet rays, and protected to cover the cross-sectional edge of the glass substrate. A material was formed. The obtained protective material had a radius of curvature r of 296 μm and d of 190 μm.

<Comparative Example 1>
In the same manner as in Example 1, a frame region and a display region were formed on one surface of the two-sided tempered glass substrate, and in the same manner, the glass substrate was cut and chamfered at the end of the cross section to produce a touch panel. .

<Evaluation and method>
The touch panel produced in Example 1 and Comparative Example 1 was subjected to a 4-point bending test by the following method.

  The glass end face of the touch panel was subjected to a scratch test with a sandpaper (# 320) at an angle of 45 °, a speed of 20 mm / s, and a load of 250 gf, and then “JIS R 1601 Bending strength test method of fine ceramics”. Accordingly, the glass strength was measured by a four-point bending test. The speed at which the pressurizer was lowered was 10 mm / min. Such strength measurement was performed on 25 glass substrates, and an average value was obtained. The results are shown in Table 1 below.

<Comparison result>
The touch panel which is the product of the present invention obtained in Example 1 was able to be suppressed to a strength reduction rate of 13% with respect to the initial strength in the four-point bending test. On the other hand, the touch panel without the protective material obtained in Comparative Example 1 had a strength reduction rate of 88% and did not reach a practical level.

  The touch panel which is the product of the present invention obtained in Example 1 can sufficiently secure the maximum thickness f "of the protective material in the 45 ° direction from the shoulder portion by satisfying the predetermined formula, from the 45 ° direction. Even after the flaw test, no microcrack was generated at the glass edge, so that a four-point bending test could suppress a decrease in strength.

  The touch panel and the cover glass of the present invention can be used as input means for various devices and the like, regardless of whether they are large or small, by incorporating a display device such as a liquid crystal display or an organic EL display.

DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... Protective material 3 ... Chamfering shoulder part of glass substrate cross section

Claims (7)

On one side of the two-sided tempered glass substrate having a chemically strengthened layer on the front and back, it is divided into a display region and a decorative frame formed on the outer periphery thereof, and the end of the glass substrate is chamfered, It is a cover glass integrated touch panel sensor substrate that is covered with a protective material on the outside in an arc shape,
The thickness of the glass substrate is t, the distance from the chamfered shoulder to the arc of the protective material orthogonal to the intersection of the 45 ° straight line and the chamfered end is f, the curvature of the protective material When the radius is r and the distance from the center in the thickness direction of the glass substrate to the chamfered outermost edge of the protective material starting from the shoulder of the glass substrate is d, d = √2f + r− [r ² − ( t / 2) ² ] A cover glass-integrated touch panel sensor substrate characterized by satisfying the formula of ^1/2 . When j is the chamfered outermost end of the glass substrate from the shoulder portion of the glass substrate, k is the width of the outermost end, and A = t / 2 + r−d + √2f, j = [A + (− A ^{2 2. The method according} to claim 1, wherein the following equation is satisfied: + 2r ² ) ^1/2 ] / 2−r + d, k = 2 {[A + (− A ² + 2r ² ) ^1/2 ] / 2−√2f}. Cover glass integrated touch panel sensor substrate.   3. The cover glass-integrated touch panel sensor substrate according to claim 1, wherein a thickness t of the glass substrate is in a range of 0.3 mm ≦ t ≦ 1.1 mm.   The cover glass integrated touch panel sensor substrate according to any one of claims 1 to 3, wherein a radius of curvature of the end chamfer of the glass substrate is infinite. The chamfered shape of the protective material is circular with the center point in the thickness direction of the glass substrate as a base point, and the maximum thickness f ″ of the protective material in the 45 ° direction from the shoulder is f ″ = f + [(− 5. The cover glass integrated touch panel sensor according to claim 1, wherein the formula: r / √2 + A / 2) ² + (r / √2−A / 2) ² ] ^1/2 is satisfied. substrate.   Between the thickness t of the glass substrate and the radius of curvature r of the protective material, the constant α satisfies the equation r = t / 2 (1 + α) in the range of 0 ≦ α ≦ 0.2. The cover glass-integrated touch panel sensor substrate according to any one of claims 1 to 5. The cover glass for laminating on the touch panel sensor substrate, the ends of the two-sided tempered glass substrate having a chemically strengthened layer on the front and back are chamfered, and the outside is covered with a protective material in an arc shape,
The thickness of the glass substrate is t, the distance from the chamfered shoulder to the arc of the protective material orthogonal to the intersection of the 45 ° straight line and the chamfered end is f, the curvature of the protective material When the radius is r and the distance from the center in the thickness direction of the glass substrate to the chamfered outermost edge of the protective material starting from the shoulder of the glass substrate is d, d = √2f + r− [r ² − ( t / 2) ² ] Cover glass characterized by satisfying the formula of ^1/2 .

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