KR20120074229A - Glass substrate of cover glass for mobile electronics device, image display apparatus for mobile electronics device, mobile electronics device, manufacturing method of glass substrate of cover glass for mobile electronics device - Google Patents

Abstract

PURPOSE: A glass substrate of a cover glass, an image display for portable electronic machine, portable electronic machine, and a manufacturing method of glass substrate of the cover glass for the portable electronic machine are provided to manufacture glass substrate of a cover glass having an excellent shock resistance. CONSTITUTION: A glass substrate(10A) of a cover glass comprises a surface(20U), a back surface(20B) and end surfaces(40A). At least a part of the end surface is formed by an etching processing. Compressive stress layers(30U,30B) are formed on the surface and the back surface by an ion exchange technique. The thickness of the compressive stress layer on center part of the surface and the back surface, end part of the surface and the back surface are identical. The end surface of the glass substrate comprises a domain which accomplishes a flat plane which is formed by polishing and a domain which accomplishes a curved surface having a surface roughness of 10 nano meters.

Description

Glass substrate of cover glass for portable electronic device, image display device for portable electronic device, portable electronic device, and glass substrate for cover glass for portable electronic device MOBILE ELECTRONICS DEVICE, MANUFACTURING METHOD OF GLASS SUBSTRATE OF COVER GLASS FOR MOBILE ELECTRONICS DEVICE}

The present invention relates to a glass substrate of a cover glass for a portable electronic device, an image display device for a portable electronic device, a portable electronic device, and a glass substrate manufacturing method of a cover glass for a portable electronic device.

In portable electronic devices equipped with image display panels such as liquid crystal panels and organic EL panels, such as mobile phones, cover glass is provided to protect the image display panels. Such cover glass for portable electronic devices is produced, for example, as follows. First, plate-shaped glass is cut | disconnected to a predetermined shape, and small pieced plate-shaped glass is produced. Then, the fragmented plate glass is immersed in molten salt and chemically strengthened. Thereafter, various functional films such as antireflection films are formed on the surface of the chemically strengthened plate glass (Japanese Patent Laid-Open No. 2007-99557 (paragraphs 0042, 0043, 0056, 0057, etc.)). That is, in the technique described in Japanese Patent Laid-Open No. 2007-99557, a chemical strengthening step is performed after the cutting step. Moreover, the technique which performs a cutting process by an etching in the case of performing a cutting process and a chemical strengthening process in the same procedure as the technique of Unexamined-Japanese-Patent No. 2007-99557 is proposed (WO2009 / 078406 (patent claims, etc.)). ).

In the technique described in WO2009 / 078406, cutting of plate glass is performed by wet etching (chemical etching), and cutting by dry etching is also known (Japanese Patent Application Laid-Open No. 63-248730 (claims, lower right of page 3). In addition, in the technique described in Japanese Patent Laid-Open No. 63-248730, it is also proposed to cut various types of functional films by etching after forming a film on the plate-shaped glass, but as a cutting method of the plate-shaped glass, scribe cutting is usually performed rather than etching. On the other hand, when scribe cutting is performed on cold-tempered glass or chemically tempered glass, the cold-tempered glass is crushed, and the chemically tempered glass cannot be divided along the scribe line, or the glass substrate obtained by scribe cutting is It is pointed out that breakage occurs under a load smaller than the assumed load (Japanese Patent Laid-Open No. 2004-83378). (Claim 1, Paragraph No. 0007, Example, etc.) Therefore, in the technique disclosed in Japanese Patent Laid-Open No. 2004-83378, the thickness of the compressive stress layer is 10 µm to 10 m to accurately cut the chemically strengthened glass along the scribe line. It is proposed to use chemically strengthened glass in the range of 30 µm and in the value of the compressive stress in the range of 30 kgf / mm 2 to 60 kgf / mm 2.

In addition, as the prior art related to the present invention, for example, as shown in Japanese Patent Laid-Open No. 2008-247732 (claims, etc.), a large-sized chemically strengthened glass is cut by physical processing such as laser cutting or scribe cutting. The technique is known.

Japanese Patent Laid-Open No. 2007-99557 (paragraphs 0042, 0043, 0056, 0057, etc.) WO2009 / 078406 (claims, etc.) Japanese Patent Laid-Open No. 63-248730 (Patent Claims, page 3, bottom right) Japanese Patent Laid-Open No. 2004-83378 (claim 1, paragraph No. 0007, Example, etc.) Japanese Patent Laid-Open No. 2008-247732 (claims, etc.)

As illustrated in Japanese Patent Application Laid-Open No. 2007-99557, WO2009 / 078406 and the like, when producing a rectangular and plate-shaped glass product (glass substrate) chemically strengthened and having a functional film formed on its surface as necessary, The ion exchange process is performed after cutting | disconnection. Therefore, the glass substrate is ion-exchanged from the front side, the back side, and the end face side. That is, the compressive stress layer is formed in the corner portion of the glass substrate by ion exchange from three directions (front side or back side, and two end face sides). Therefore, since the thickness of the compressive stress layer formed on the edge portion of the glass substrate is significantly increased compared to the thickness of the compressive stress layer formed on the edge portion of the glass substrate, distortion stress tends to be concentrated. Therefore, the impact resistance of the edge portion is inferior.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a glass substrate of a cover glass for a portable electronic device having excellent impact resistance at a corner portion, an image display device for a portable electronic device and a portable electronic device using the same, and a glass substrate of a cover glass for a portable electronic device. It is a subject to provide a manufacturing method.

The said subject is achieved by the following this invention. In other words,

The glass substrate of the cover glass for portable electronic device according to the first aspect of the present invention is a glass substrate of the cover glass for portable electronic device, which has a surface, a back surface, and an end surface, and at least a part of the end surface is formed by etching. Each of the back surfaces is provided with a compressive stress layer formed by an ion exchange method such that the thicknesses of the layers are equal to each other at the central portion in the surface direction on the front surface and the rear surface and at the end portions in the surface direction on the front surface and the rear surface. .

In one embodiment of the glass substrate of the cover glass for portable electronic device according to the first aspect of the present invention, it is preferable that the region on the center side in the thickness direction of the glass substrate on the end face constitutes a flat surface formed by polishing.

Another embodiment of the glass substrate of the cover glass for portable electronic device according to the first aspect of the present invention is an area in which the end surface forms a flat surface formed by the polishing process and a curved surface having a surface roughness Ra of 10 nm or less. It is preferable to make.

In another embodiment of the glass substrate of the cover glass for portable electronic device according to the first aspect of the present invention, it is preferable that the end face is mirror surface.

As for another embodiment of the glass substrate of the cover glass for portable electronic devices of 1st this invention, it is preferable that at least one decoration layer is provided in at least one surface chosen from the front surface and the back surface.

Another embodiment of the glass substrate of the cover glass for portable electronic devices of the first aspect of the present invention is preferably used in at least one aspect selected from the display panel protective cover glass and the touch panel.

The glass substrate of the cover glass for a portable electronic device according to the second aspect of the present invention is a curved surface having a compressive stress layer formed by the ion exchange method only on the front side and the back side, and the end surface is convex, and the surface roughness Ra of the end surface is 10. It is characterized by being nm or less.

In the glass substrate of the cover glass for portable electronic devices according to the third aspect of the present invention, the compressive stress layer formed by the ion exchange method is provided only on the front side and the back side, and at least a portion of the end surface forms a flat surface formed by polishing. It is characterized by an area.

An image display apparatus for a portable electronic device of the present invention has an image display panel having a rectangular image display area, and a planar shape which is provided on the image display surface side of the image display panel and substantially coincides with the outline shape in the planar direction of the image display area. At least one cover glass for a portable electronic device comprising a glass substrate of the cover glass for a portable electronic device according to any one of the first, second or third of the present invention.

The portable electronic device of the present invention is a portable electronic device comprising an image display panel and a glass substrate of the cover glass for portable electronic device according to any one of the first, second or third of the present invention, provided on the image display surface side of the image display panel. At least the cover glass for electronic devices is provided.

One embodiment of the portable electronic device of the present invention is preferably a cellular phone.

The manufacturing method of the glass substrate of the cover glass for portable electronic devices of 1st this invention is ion exchange which carries out ion exchange treatment by contacting the plate-shaped glass containing 1 or more types of alkali metals with the molten salt containing 1 or more types of alkali metals. A process step, an etching-resistant film forming step of forming an etching film on at least one surface of the ion-exchanged plate-shaped glass, a patterning step of patterning at least an etching film, and a patterning of the plate-shaped glass after ion exchange treatment By etching the surface provided with the etch-resistant film in contact with the etching solution, the glass substrate is produced by at least a cutting step of cutting the plate-shaped glass after the ion exchange treatment into small pieces.

A second method for producing a glass substrate of a cover glass for a portable electronic device according to the present invention is a plate-shaped glass containing at least one alkali metal, and the ion exchange treatment step by contact with a molten salt containing at least one alkali metal. The etching-resistant film forming process of forming an etching film on at least one surface of the roughened surface and the back surface, the patterning process of patterning the etching film at least, and the patterned said The surface provided with the etching resistant film is brought into contact with an etching solution to be etched, thereby producing a glass substrate through at least a cutting step of cutting the plate-shaped glass that has been subjected to the ion exchange treatment into small pieces.

One embodiment of the method for producing a glass substrate of the cover glass for portable electronic devices according to the first and second aspects of the present invention comprises at least one of the plate-shaped glass that has been ion-exchanged after the ion exchange treatment step and before the execution of the etching-resistant film forming step. It is preferable that the decoration layer forming process of forming one or more layers of decoration layers on the surface of is performed.

It is preferable that another embodiment of the manufacturing method of the glass substrate of the cover glass for portable electronic devices of 1st and 2nd this invention further has an end surface grinding | polishing process of grinding | polishing at least one part of the cut surface formed through the cutting process.

According to the present invention, it is possible to provide a glass substrate of a cover glass for a portable electronic device excellent in impact resistance at a corner portion, an image display device for a portable electronic device and a portable electronic device using the same, and a glass substrate manufacturing method of a cover glass for a portable electronic device. .

1 is a schematic sectional view showing an example of the glass substrate of the present embodiment.
FIG. 2 is a first cross-sectional view, and is a schematic sectional view showing an example of a glass substrate prepared by ion exchange treatment of the entire surface of the plate-shaped glass cut into a predetermined shape.
3 is a second comparative example, and is a schematic cross-sectional view showing another example of a glass substrate prepared by ion exchange treatment of the entire surface of a plate-shaped glass cut into a predetermined shape.
4 is a schematic sectional view showing another first example of the glass substrate of the present embodiment.
5 is a schematic sectional view showing another second example of the glass substrate of the present embodiment.
6 is a schematic sectional view showing an example of a touch panel using the glass substrate of the present embodiment.
7 is a schematic sectional view showing an example of the image display device of the present embodiment.
8 is a side view showing an example of the portable electronic device of the present embodiment.
Fig. 9 is a schematic sectional view illustrating an example of the glass substrate manufacturing method of the present embodiment, Fig. 9 (A) is a view showing a state before the cutting step is performed, and Fig. 9 (B) shows a state during the cutting step. It is a figure.

In the following description, the glass substrate of the cover glass for portable electronic devices is simply abbreviated simply as "glass substrate", and the image display device for portable electronic devices is simply abbreviated simply as "image display device", and the cover glass for portable electronic devices is The manufacturing method of a glass substrate is suitably abbreviated simply as "manufacturing method of a glass substrate."

(Glass substrate, image display device and portable electronic device)

In the glass substrate of this embodiment, the compressive stress layer formed by the ion exchange method is provided only on the front side and the back side, and the end surface is a convex curved surface, and the surface roughness Ra of the end surface is 10 nm or less, for example.

1 is a schematic sectional view showing an example of the glass substrate of the present embodiment, and specifically, a cross section near the end face. The glass substrate 10A shown in FIG. 1 (collectively referred to as "10" when combined with other examples) is a compressive stress layer formed by an ion exchange method having a predetermined thickness on the surface 20U side and the rear surface 20B side. 30U and 30B are provided. These compressive stress layers 30U and 30B are formed by performing an ion exchange treatment by bringing the surface 20U side and the back surface 20B side into contact with molten salt.

On the other hand, the end surfaces 40A and 40 are made of curved surfaces that are convex, and the surface roughness Ra is, for example, 10 nm or less. Here, the "curved surface of which the end surface is convex" is more specifically, the top surface of which the end surface is located at the outermost side in the planar direction of the glass substrate, and from this top portion to at least one main surface side selected from the front side and the back side. It has an inclined surface formed to extend, and also means that the inclined surface is composed of a curved surface (concave curved surface) that enters the inner side of the glass substrate. The curvature is not particularly limited as long as the curved surface is an etching surface formed by isotropic etching using wet etching from the front side and / or back side when the glass substrate 10A is manufactured.

Here, in the example shown in FIG. 1, the end surface 40A forms the top part 42 which protruded so that the vicinity of the center part of the thickness direction of the glass substrate 10A may be located in the outermost side of the plane direction of the glass substrate 10A. Doing. Inclined surfaces 44U and 44B that are gently curved from the top portion 42 toward the surface 20U side and the rear surface 20B side are formed. The inclined surfaces 44U and 44B are concave surfaces that are concave inwardly of the glass substrate 10A. That is, the inclined surface 44U is formed to be concave with respect to the straight line (straight line L1 shown by dashed line in the figure) connecting the top portion 42 and the end of the surface 20U shown in FIG. 44B is formed so that it may become concave with respect to the straight line (straight line L2 shown by a dashed-dotted line in a figure) which connects the top part 42 and the end part of the back surface 20B shown in FIG. The end face 40A having such a curved shape isotropically formed from the surface 20U side and the back surface 20B side after forming the compressive stress layers 30U and 30B on the surface 20U side and the back surface 20B side. It is formed by performing wet etching which is etching. That is, the end surface 40A is the surface whose front surface was formed by wet etching. In addition, the shape of the end surface 40A has a curved surface formed by wet etching, and if the surface roughness Ra is 10 nm or less, the shape is not limited to the example shown in FIG. For example, when wet etching is performed only from the surface 20U side, the end surface 40A is comprised of the inclined surface 44U and the top part 42 located in the back surface 20B side.

The end face 40A does not have a compressive stress layer formed by ion exchange treatment except that the compressive stress layers 30U and 30B exist on the front surface 20U side and the back surface 20B side. Therefore, the compressive stress layer 30U at the corner portion 50U, which is the boundary between the surface 20U and the end surface 40A, and the corner portion 50B, which is the boundary between the back surface 20B and the end surface 40A. The thickness of 30B (ie, the thickness of the end in the plane direction at the surface 20U) is substantially the same as the thickness of the compressive stress layers 30U and 30B near the center of the glass substrate 10A. Therefore, the distortion stress is not concentrated in the corner portion 50U and the corner portion 50B. In addition, the edge parts 50U and 50B shown in FIG. 1 are a boundary part between main surface 20 (20U, 20B) and the end surface 40A, ie, a boundary part between two surfaces. However, the thickness of the compressive stress layers 30U and 30B is the boundary between the main surface 20, the end surface 40A, and the other end surface (not shown in the figure) that intersects the end surface 40A, that is, three surfaces. The corner portion formed as the boundary portion therebetween is also substantially the same as the thickness of the compressive stress layers 30U and 30B in the vicinity of the central portion of the glass substrate 10A. For this reason, the edge portion formed as the boundary portion between the three surfaces (hereinafter, the "three-side edge) is the same as the edge portion formed as the boundary portion between the two surfaces (hereinafter sometimes referred to as" two-side edge portion "). Part), which may not be concentrated in the distortion stress. Therefore, the deterioration of the impact resistance caused by the concentration of the distortion stress does not occur at any corner portion. In addition, three-sided corners correspond to eight vertices.

On the other hand, ion exchange treatment is performed on a plate-like glass (glass before ion exchange treatment) having the same cross-sectional shape as the glass substrate 10A shown in FIG. 1, or a plate-shaped glass (glass before ion exchange treatment) that has been fragmented by scribe cutting. By doing this, a glass substrate having a structure similar to that of the glass substrate 10A shown in FIG. 1 can be obtained. 2 and 3 are examples of glass substrates prepared by ion exchange treatment of the entire surface of the plate-shaped glass cut into a predetermined shape, and are schematic cross-sectional views showing first and second comparative examples. Here, the glass substrate shown in FIG. 2 is manufactured using plate-like glass cut by wet etching the same as the glass substrate 10A shown in FIG. 1, and the glass substrate shown in FIG. 3 is obtained by scribe cutting. It was produced using plate glass. Here, the same reference numerals are given to those having the same shapes as those shown in FIG. 1 in FIGS. 2 and 3.

In the glass substrate 200 shown in FIG. 2, the compressive stress layer 32 which is continuous from the main surface 20 (20U, back surface 20B) side to the end surface 40A side is formed, and FIG. In the glass substrate 210 shown in the drawing, a compressive stress layer 34 is formed which is continuous from the main surface 20 (the surface 20U and the rear surface 20B) to the end surface 46 side. In addition, the end surface 46 shown in FIG. 3 is a flat surface formed by scribe cutting. In the case of manufacturing the glass substrate 200, ion exchange in the vicinity of the corner portions 50U and 50B is performed through two surfaces of the main surface 20 and the end surface 40A. In the case of manufacturing the glass substrate 210, this point is a corner portion 52U, which is a boundary between the surface 20U and the end surface 46, and a corner portion, which is a boundary between the back surface 20B and the end surface 46. The same applies to ion exchange in each of the vicinity of (52B). Therefore, the thickness of the compressive stress layer 32 in each vicinity of the corner portions 50U and 50B, and the thickness of the compressive stress layer 34 in each vicinity of the corner portions 52U and 52B are different from those of the other portions. In comparison, it becomes thick, and distortion stress becomes easy to concentrate. In addition, the increase in the thickness of the compressive stress layer and the concentration of the distortion stress become more remarkable at the three surface edge portions that are ion exchanged from three surfaces. That is, in terms of impact resistance at corners, particularly at three corners, the glass substrate 10A of the present embodiment shown in FIG. 1 is more than the glass substrates 200 and 210 shown in FIGS. 2 and 3. Quite excellent.

On the other hand, when microcracks (microcracks) exist on the surface of the glass, the concentration of stress tends to occur from the microcracks as a starting point, and the glass is easily broken by such stress concentration. In the cut surface formed by wet etching, the microcracks as described above are removed by wet etching using a chemical reaction, and thus stress concentrations originating from the microcracks are hardly generated. However, the cut surface formed by machining such as scribe cutting is formed by applying a physical external force. Therefore, it is difficult to avoid the occurrence of microcracks in the cut surface. In consideration of the circumstances described above, it is considered that the glass substrate 10A of the present embodiment shown in FIG. 1 is more excellent in impact resistance at the end surface than the glass substrate 210 shown in FIG. 3.

Here, the end surface 40A of the glass substrate 200 is preferably mirror surface from the viewpoint of mechanical strength and appearance. This mirror surface is a surface well finished so that an object is projected like a mirror with respect to a surface having a myriad of fine irregularities. For example, when the surface roughness (arithmetic mean roughness Ra) in two directions orthogonal to each other on one surface is 0.1 µm or less, the surface may be defined as a mirror surface.

The surface roughness Ra (arithmetic mean roughness) of the end surface 40A may be 10 nm or less, but is preferably 5 nm or less. In addition, the minimum of surface roughness Ra is although it does not specifically limit, It is 0.1 nm or more practically. Surface roughness Ra of 10 nm or less can be easily implement | achieved by the wet etching at the time of forming the end surface 40A. In addition, surface roughness Ra can be measured by AFM (atomic force microscope).

In addition, the thicknesses of the compressive stress layers 30U and 30B are appropriately selected depending on the use of the glass substrate, and preferably 10 µm or more from the viewpoint of securing the scratch resistance of the main surface 20 and the impact resistance of the glass substrate 10A. It is more preferable that it is 30 micrometers or more, and it is more preferable that it is 40 micrometers or more. On the other hand, the upper limit of the thickness of the compressive stress layers 30U and 30B is not particularly limited, but the stress balance on the surface 20U side and the back surface 20B side at the time of cutting by wet etching or increase in time required for ion exchange treatment. It is preferable to set it to 100 micrometers or less from a practical point of view, such as to prevent spontaneous crushing (self-destruction) during manufacture of the glass substrate 10A due to deterioration, and it is more preferable to set it to 70 micrometers or less. In addition, the thickness of the compressive stress layer 30U and the thickness of the compressive stress layer 30B may be different. In this case, however, the stress balance on the front and back surfaces of the glass substrate 10A is broken, and the glass substrate 10A is easily bent. Therefore, it is usually preferable that the thickness of the compressive stress layer 30U and the thickness of the compressive stress layer 30B are approximately the same.

Although the thickness of the glass substrate 10A is not particularly limited, it is generally 1 mm or less, preferably 0.7 mm or less, from the viewpoint of suppression of weight increase of various devices using the glass substrate 10A and thinning of the device. desirable. The lower limit of the plate thickness is preferably 0.2 mm or more from the viewpoint of securing the mechanical strength of the glass substrate 10A.

In addition, although the glass substrate 10 of this embodiment may be comprised only by the main body of the glass substrate 10A, as shown in FIG. 1, the surface 20U and the back surface 20B according to the usage of the glass substrate 10 are used. It is good also as a glass substrate (glass substrate with a film | membrane) provided with one or more decorative layers in the at least one surface chosen from the. FIG. 4 is a schematic sectional view showing another first example of the glass substrate of the present embodiment, and specifically shows a configuration in which a decorative layer is provided on the surface 20U side of the glass substrate 10A shown in FIG. 1. . In the glass substrate 10B shown in FIG. 4, one decorative layer 60 is provided on the surface 20U of the main body of the glass substrate 10A. As the decorative layer 60, a layer having optical functions such as (1) AR coat (anti reflection coat), anti-glare coat, half mirror coat, polarizing film, and (2) transparent electrode represented by ITO (Indium Tin Oxide) film Examples thereof include layers having an electrical function such as a film, and layers having a function of improving aesthetics such as (3) a printed layer. In addition, by stacking and patterning the plurality of decorative layers 60, various devices such as a touch panel can be formed on the main body of the glass substrate 10A.

In the glass substrate 10 of the present embodiment, at least a portion of the end surface 40A of the glass substrate 10A having the end surface 40A having the convex curved surface as illustrated in FIG. It may be polished to an area forming a flat surface. In this case, the end surface after the polishing treatment may be a flat surface formed by the polishing treatment, the region forming the flat surface formed by the polishing treatment, and the curved surface having a surface roughness Ra of 10 nm or less. It may be composed of an area. In addition, the area | region which comprises the flat surface formed by the grinding | polishing process is formed in the form which removes at least the top part 42 and its vicinity by grinding | polishing, and the flat surface formed by the grinding | polishing process has the surface 20U and the back surface 20B. It is preferable that it is a plane orthogonal to. In this case, for example, the region on the center side in the thickness direction of the glass substrate 10A on the end surface 40A becomes a region forming a flat surface formed by polishing. As a result, the protruding portion due to the top portion 42 does not exist on the end surface after the polishing process, so that the flatness of the end surface portion and the dimensional precision of the vertical and horizontal dimensions can be further improved with respect to the glass substrate 10A shown in FIG. Can be.

As the polishing treatment, a known mechanical polishing treatment such as brush polishing can be employed. In addition, as the polishing treatment, a known chemical polishing treatment such as an etching treatment may be employed.

FIG. 5 is a schematic sectional view showing another second example of the glass substrate of the present embodiment. Specifically, the top portion 42 and the vicinity of the glass substrate 10A shown in FIG. 1 are removed by polishing. Fig. 2 shows an embodiment in which a flat surface is formed on a part of the end surface. 5, the same code | symbol is attached | subjected about the same thing as FIG. In the glass substrate 10C shown in Fig. 5, the end surfaces 40B and 40 are inclined surfaces 44U1 located on the surface 20U side, inclined surfaces 44B1 located on the rear surface 20B side, and inclined surfaces 44U1. ) And a flat surface (polishing surface) 48 formed by removing the top portion 42 and its vicinity by polishing treatment, located between the inclined surface 44B1 and the inclined surface 44B1. Here, the flat surface 48 is a surface substantially orthogonal to the surface 20U and the rear surface 20B. Except for the above, the glass substrate 10C shown in FIG. 5 has the same configuration as the glass substrate 10A shown in FIG. In addition, the decorative layer 60 may be further provided on the surface 20U and / or the rear surface 20B of the glass substrate 10C as illustrated in FIG. 4.

The use of the glass substrate 10 of the present embodiment is not particularly limited, but considering the excellent impact resistance and the scratch resistance of the main surface 20, the surface impact resistance and / or the scratch resistance is required. It is preferable to use. As such a use, the various display panel protective cover glass (henceforth abbreviated as "cover glass") and a touch panel, such as a liquid crystal panel, an organic EL panel, and a plasma display panel, are typical.

6 is a schematic sectional view showing an example of a touch panel using the glass substrate of the present embodiment. In addition, the description about the specific end surface structure of the glass substrate 10 shown in FIG. 6 is abbreviate | omitted. The touch panel 100 shown in FIG. 6 is disposed on the surface 20U of the glass substrate 10 so as to face the first transparent conductive film 102 and the first transparent conductive film 102 via spacers 104. The second transparent conductive film 106 and the resin film layer 108 provided on the side opposite to the side where the glass substrate 10 of the second transparent conductive film 106 is provided. The touch panel 100 is in contact with the first transparent conductive film 102 and the second transparent conductive film 106 by pressing the surface 108A of the resin film layer 108 so that the first transparent conductive film 102 and the second transparent conductive film 102 are in contact with each other. An electric current flows between the transparent conductive film 106, and the conduction of the first transparent conductive film 102 and the second transparent conductive film 106 is interrupted by the release of pressure. The current ON / OFF is then transmitted to the control circuit (not shown) connected to the touch panel 100 as input information, and the control circuit is arranged on the back surface 20B side of the glass substrate 10. Touch panel operation is realized by transferring display information according to input information to a displayed display (not shown).

7 is a schematic sectional view showing an example of the image display device of the present embodiment. 7 shows the configuration of the main part of the image display apparatus, and descriptions of other configurations are omitted. In addition, the description about the specific cross-sectional structure of the glass substrate 10 of this embodiment shown in FIG. 7 is abbreviate | omitted. The image display apparatus 110 shown in FIG. 7 includes a panel frame 112, an image display panel 114 such as a liquid crystal panel held in the panel frame 112, and an image display surface of the image display panel 114. At least the glass substrate 10 is disposed on the image display surface 114A so as to cover approximately the entire front surface of the 114A. In the example shown in FIG. 7, the image display surface 114A and the glass substrate 10 may be in close contact with each other, a minute gap may be provided between them, and another layer such as a resin film may be disposed therebetween. You may be. In addition, the image display apparatus 110 may function independently as a unit, or may constitute a part of other electronic devices such as a display panel portion of a portable electronic device such as a cellular phone.

In addition, the end surface 40 of the glass substrate 10 is completely exposed in the example shown in FIG. 7 and forms substantially the same surface as the side surface 112S of the panel frame 112. However, since the glass substrate 10 is disposed to be filled in the panel frame 112 together with the image display panel 114, the end surface 40 may not be exposed. However, from the viewpoint of design, it is often desirable that the end face 40 is completely exposed, as illustrated in FIG. 7. Therefore, from the viewpoint of design improvement, the end face 40 is also preferably in an exposed state. In this case, when the image display apparatus 110 collides with the floor, the wall, or the like, the corner portion 50 of the glass substrate 10 is directly exposed to mechanical shock. However, the glass substrate 10 of the present embodiment is excellent in impact resistance of the corner portion 50, so that the breakage of the cover glass as compared with the case of using the glass substrates 200 and 210 illustrated in Figs. Are less likely to occur. Therefore, from the viewpoint of impact resistance, the glass substrate 10 of the present embodiment can further increase the degree of freedom in appearance design of the image display apparatus provided with the cover glass.

In addition, the image display panel 114 typically has a rectangular image display area on the image display surface 114A side. In this case, as the cover glass provided on the image display surface 114A side of the image display panel 114, the glass substrate 10 of the present embodiment has a planar shape substantially coincident with the contour shape in the planar direction of the image display area. It is also preferable to use. This is because the image quality of the four corners of the screen is not degraded. The reason is as follows. First, in the glass substrates 200 and 210 illustrated in FIGS. 2 and 3, the thicknesses of the compressive stress layers 32 and 34 near the three side edges are the compressive stress layers 32 and 34 except the three side edges. It is considerably thicker than its thickness. In addition, the compressive stress layers 32 and 34 have different refractive indices in the vicinity of the three-sided edge portion and in the other portion. Therefore, the difference in the thickness of the compressive stress layers 32 and 34 in the vicinity of the three-sided edge portion and the non-sided portion is the difference in the polarization or scattering state of the light between the three-sided edge portion of the cover glass surface and the portion that is not. Will result. Therefore, when the glass substrates 200 and 210 having the planar shape substantially coincident with the contour shape in the planar direction of the image display area are used as the cover glass, the appearance of the image at the four corners of the screen is the four corners of the screen. It will look different from the rest. However, in the glass substrate 10 of the present embodiment, the thickness of the compressive stress layer near the three side edges and the thickness of the compressive stress layer except the three side edges are approximately the same, thus avoiding the above-mentioned problems. can do. In addition, "a planar shape substantially coincident with the contour shape in the planar direction of the image display area" has a size projecting outward or inward within a range of ± 10 mm with respect to the contour line constituting the planar contour shape of the image display area. It means a planar shape.

In addition, the ratio of the four corner portions and the occupying area occupying the entire image display area becomes relatively larger as the area of the image display area becomes smaller. This means that when the image quality deterioration of the four corner portions occurs, the smaller the size of the image display area, the greater the discomfort of the image appearance of the four corner portions for the viewer of the image. In consideration of this point, the size of the image display area is preferably 1.5 inches or more, and more preferably 2.0 inches or more in the length of the diagonal. The lower limit of the size of the image display area is not particularly limited, but is preferably 5.0 inches or less in diagonal length for practical use.

As a more preferable use aspect of the glass substrate 10 of this embodiment, what is used as a cover electronics of portable electronic devices, especially the cover glass of an image display panel and the cover glass provided in the image display surface side of an image display panel at least. desirable. Portable electronic devices, in particular mobile phones, are often exposed to mechanical shocks from the edges of the cover glass, and various designs are often required. However, the glass substrate 10 of this embodiment responds easily to both requests as mentioned above.

Fig. 8 is a side view showing an example of the portable electronic device of the present embodiment, specifically showing a mobile phone having the glass substrate 10 of the present embodiment as a cover glass on the image display surface side of the image display panel. to be. The mobile telephone 120 shown in FIG. 8 includes a main body 122, a display unit 124 including an image display panel, and a hinge unit for rotatably connecting the main body 122 and the display unit 124. FIG. 126 and a glass substrate 10 disposed so as to cover substantially the entire surface of the image display surface 124A of the display unit.

As the glass material constituting the glass substrate 10 of the present embodiment, any glass material may be used as long as it is a glass material containing an alkali metal oxide capable of ion exchange treatment. Aluminosilicate glass containing SiO ₂ , Al ₂ O ₃ and at least one alkali metal oxide selected from Li ₂ O and Na ₂ O used in the production, (2) of plate glass using a float method or the like. It is preferable to use well-known glass materials, such as soda-lime glass used for preparation. In addition, when the glass substrate 10 is manufactured from the plate glass using the down-draw method, compared with the float method etc., the plate glass surface has few scratches, and the smoothness of the plate glass surface becomes nanometer order roughness. For this reason, at the time of manufacturing the glass substrate 10, the mirror polishing for forming the main surface 20 can be omitted, and the occurrence of micro cracks present in the main surface 20 can be extremely reduced.

And also aluminosilicate glass as the productivity of the plate-like glass, the mechanical strength, chemical, and 62 wt.% To 75 wt% of SiO ₂ from the point of view such as in practical use, such as durability, 5 to 15 wt% of Al ₂ O _3, 0 to 8% by weight of Li ₂ O, 4 to 16% by weight of Na ₂ O, 0 to 6% by weight of K ₂ O, 0 to 12% by weight of ZrO ₂ , and 0 to 6 It is more preferred to include MgO in weight%.

In addition, the compressive stress layer is a deteriorated layer in which a part of the alkali metal originally included in the glass material constituting the glass substrate 10 is replaced with an alkali metal having a larger ion radius. For example, if the alkali metal originally included in the glass material constituting the glass substrate 10 is Li, it is substituted with Na, K, and the like. If the alkali metal originally contained in the glass material constituting the glass substrate 10 is Na, K or the like.

(Method of manufacturing glass substrate)

Next, the manufacturing method of the glass substrate 10 of this embodiment is demonstrated. First, the glass substrate 10A illustrated in FIG. 1 includes an ion exchange treatment step of performing ion exchange treatment by contacting a plate-shaped glass containing at least one alkali metal with a molten salt containing at least one alkali metal, and an ion exchange treatment. The etching solution is formed by etching a film forming process to form an etching film on at least one surface of the finished plate glass, a patterning process of patterning the etching film at least, and a surface on which the patterned etching film is formed of the plate glass after ion exchange treatment. By contacting and etching, it can be produced by at least going through a cutting step of cutting the ion-exchanged plate-like glass into small pieces. Each process is explained in full detail below.

Ion Exchange Treatment Process

In the ion exchange treatment step, the plate-like glass containing at least one alkali metal is brought into contact with a molten salt containing at least one alkali metal to perform ion exchange treatment. In this ion exchange treatment step, the plate glass is usually immersed in the molten salt to thereby ion exchange the both surfaces of the plate glass. The composition, temperature, and immersion time of the molten salt can be appropriately selected depending on the glass composition of the plate glass, the thickness of the compressive stress layer formed on the surface layer portion of the plate glass, and the like. For example, when the glass composition of plate-shaped glass is the aluminosilicate glass and soda-lime glass mentioned above, it is preferable to select the composition, temperature, and immersion time of a molten salt generally from the range illustrated below.

(1) Composition of molten salt: mixed salt of potassium nitrate or potassium nitrate with sodium nitrate

(2) Temperature of molten salt: 320 ℃ ~ 470 ℃

(3) Immersion time: 3 ~ 600 minutes

Etching-resistant film forming process

In the etching-resistant film forming step, the etching-resistant film is formed on at least one surface of the plate-shaped glass which has been subjected to the ion exchange treatment. This etching film is usually formed on both surfaces of the plate-shaped glass which has been subjected to the ion exchange treatment. When only one surface is brought into contact with the etching solution in the cutting step, the etching film should be formed only on this surface. In addition, in the following description, it demonstrates on the premise that a etch-resistant film is formed in both surfaces of the plate glass after ion exchange treatment. The etch-resistant film can be appropriately selected as long as it has a property of being partially removable by the patterning process in the patterning step and not being melted or removed with respect to the etching solution used in the cutting step. As such an etching-resistant film, it is preferable to use a resist film that exhibits poor solubility or insolubility in at least the aqueous hydrofluoric acid solution. In this case, in the patterning step, the resist film can be patterned by exposure treatment using a photomask and development treatment with a developing solution, and cutting can be performed using an etching solution in the cutting step.

Patterning Process

In the patterning process, at least an etching film is patterned. This removes the etching film other than the region corresponding to the shape in the planar direction of the glass substrate 10 finally produced among the etching films covering the entire surface of the plate-shaped glass after ion exchange treatment. As a patterning method of an etching-resistant film, photolithography which performs combining the exposure and phenomenon mentioned above typically can be used. In addition, the patterning process may be performed on at least one surface of the plate-shaped glass after the ion exchange process in which the etching film was formed on both surfaces, and may be performed on both surfaces. In the latter case, as shown in Fig. 1, after the cutting step, the end face 40A having the top 42 and the two inclined surfaces 44U and 44B is formed in the cross-sectional shape.

Cutting process

In the cutting step, the ion-exchanged plate-shaped glass is cut into small pieces by etching the surface of the plate-shaped glass on which the patterned inner etching film is provided in contact with an etching solution. An etching process is normally performed by immersing plate-shaped glass in the etching solution. The etching solution is not particularly limited as long as it contains at least hydrofluoric acid, but other additives such as hydrochloric acid and the like, and various additives such as surfactants may be added as necessary.

FIG. 9 is a schematic sectional view illustrating an example of the glass substrate manufacturing method of the present embodiment, and specifically, illustrates an example of a cutting step in the case of producing the glass substrate 10A shown in FIG. 1. Here, FIG. 9 (A) is a figure which shows the state before carrying out a cutting process, In other words, it shows the state after the etch-resistant film formed in the plate-shaped glass after ion exchange processing was patterned. 9B is a diagram showing a state during the cutting step. In addition, in FIG. 9, the description about the compressive stress layer formed in plate-shaped glass is abbreviate | omitted.

In the state before performing the cutting process shown to FIG. 9 (A), the etching-resistant film 70 (70U, 70B) is formed in both surfaces of the plate-shaped glass 12. As shown in FIG. In addition, openings 72 (72U, 72B) are formed in the etching-resistant films 70 (70U, 70B) so that the surface of the plate-shaped glass 12 is exposed by the patterning process. In addition, the opening 72U provided on one side of the plate-shaped glass 12 and the opening 72B provided on the other side are provided at the same position in the planar direction of the plate-shaped glass 12, and the opening 72U and the opening 72B. The width of is the same. In addition, the opening 72 is formed in a band shape so as to extend inward from the front of the ground in FIG.

Next, the plate glass 12 with the etching-resistant film 70 provided with the opening 72 shown in FIG. 9A is immersed in an etching solution (not shown in FIG. 9). In this case, the etched solution penetrating into the opening 72 selectively etches only the plate glass 12 exposed to the bottom of the opening 72. And as shown in the arrow direction of FIG. 9 (B), the etching of the plate-shaped glass 12 advances substantially isotropically from both surfaces of the plate-shaped glass 12 using the bottom side of the opening part 72 as a starting point. Therefore, the glass substrate 10A obtained through the cutting process has an end face 40A made of a convex curved surface as shown in FIG. In the wet etching using the etching solution, since the etching surface is smoothed, the surface roughness Ra of the end surface 40A can be easily set to 10 nm or less in two directions orthogonal to each other. That is, the end surface 40A can be finished as a mirror surface.

Decorating layer forming process

In addition, when manufacturing the glass substrate 10B in which the decoration layer 60 shown in FIG. 4 was formed instead of the glass substrate 10A shown in FIG. 1, after performing an ion exchange process process, it also becomes an etching-resistant film forming process. Before implementation, a decorative layer forming step of forming one or more decorative layers 60 on at least one surface of the ion exchanged plate-shaped glass is performed. In this case, an etching resistant film is formed on the surface of the decorative layer 60 in the etching resistant film forming step.

In the case where only the etching film is patterned in the patterning step, the decorative layer 60 and the plate-shaped glass in the region where the etching film is removed in the cutting step are etched and cut. In this case, as a composition of the etching solution used at a cutting process, the composition which does not erode an etching film and erodes both the decorating layer 60 and plate-shaped glass is selected.

On the other hand, when patterning the etching-resistant film and the decorating layer 60 at the same time in a patterning process, the plate-shaped glass of the area | region where the etching-resistant film and the decorating layer 60 was removed is etched and cut | disconnected. In this case, as a composition of the etching solution used at a cutting process, the composition which does not corrode both an etching film and the decorating layer 60, and also corrodes plate-shaped glass is selected.

As the film forming method of the decorating layer 60, a known film forming method can be appropriately used according to the material, film thickness, etc. constituting the decorating layer 60. For example, various printing methods such as screen printing, dipping, spraying, etc. Known liquid film methods such as a coating method, a sol gel coating method, and a plating method, and known vapor deposition methods such as a vacuum deposition method, a sputtering method, and a chemical vapor deposition (CVD) method can be used.

In the glass substrate manufacturing method of this embodiment described above, in order to produce the glass substrate 10, after carrying out the ion exchange treatment process and the decorative layer forming process performed as needed in the state of the large plate-shaped glass 12, In order to reduce the plate glass 12, a cutting process is performed. To this end, the glass substrate illustrated in FIGS. 2 and 3 is subjected to ion exchange treatment and formation of a decorative layer, if necessary, in a state where the plate-shaped glass 12 is previously small-sized into the same size as the glass substrate 10. Compared with the case of manufacturing the glass substrates having the decoration layer 60 formed on the glass substrates 200 and 210 or the glass substrates 200 and 210, the glass substrate manufacturing method of the present embodiment is excellent in productivity and cost. (2) The dimensional accuracy of the glass substrate produced is also excellent.

(1) In terms of productivity and cost, the plate-like glass 12 to be used is larger than the case where the plate-shaped glass 12 to be used is smaller in size when the ion exchange treatment or the decoration layer is formed. When the size is small and small, the sheet glass 12 of several sheets must be handled. For example, in the case of performing the ion exchange treatment, when immersing a plurality of pieces of the plated glass 12 in the molten salt, a plurality of pieces of the small pieces of the holder holding the plate-shaped glass 12 in the molten salt The plate glass 12 must be set. Therefore, compared with the case where the plate-shaped glass 12 of a large size is used, when the plate-shaped glass 12 which has become small is used, the working efficiency at the time of setting the plate-shaped glass 12 by a holder is considerably bad.

(2) The reason why the dimensional accuracy of the glass substrate to be produced is excellent is that in the glass substrate manufacturing method of the present embodiment, after the ion exchange treatment involving the dimensional change of the plate-shaped glass 12 is performed, cutting is performed using wet etching. It can be mentioned. In other words, in the case where the ion exchange treatment is performed using the plated glass 12 which has been subjected to the cutting treatment using wet etching, scribe cutting, or the like, in order to obtain a glass substrate having a desired size, it is necessary to carry out the ion exchange treatment. After predicting the dimensional change, the cutting process must be performed. However, there is a variation in the degree of dimensional change that occurs with the ion exchange treatment. Therefore, even if the cutting process is performed with high accuracy, variations are likely to occur in the dimensions of the glass substrate obtained. On the other hand, in the glass substrate manufacturing method of the present embodiment, even if the dimensional change occurs in the ion exchange treatment, the size of the glass substrate 10 is determined by the cutting process using wet etching performed after that. Therefore, it is quite easy to control the dimension of the glass substrate 10 to a desired value.

End surface polishing process

The glass substrate manufacturing method of the present embodiment may further have an end surface polishing step of polishing at least a part of the cut surface formed through the cutting step. Here, the cut surface means an end surface made of a convex curved surface formed by wet etching, such as the end surface 40A as illustrated in FIGS. 1 and 4, for example. By performing this end surface polishing step, it is possible to obtain a glass substrate composed of a region in which at least a portion of the end surface forms a flat surface formed by polishing, as in the glass substrate 10C illustrated in FIG. 5. Here, with respect to the end surface 40A of the glass substrate 10B shown in FIG. 4, the top part 42 and its vicinity are removed by grinding | polishing process, and it processed to become the end surface 40B as shown in FIG. In this case, abrasion, breakage or peeling on the end surface 40B side of the decorative layer 60 by the polishing treatment can be prevented.

[Example]

Although an Example of this invention is given to the following and it demonstrates in more detail, this invention is not limited only to a following example.

Example 1

Plate-shaped glass (0.5 mm thick, 400 mm x 320 mm thick) made of aluminosilicate glass produced by the down draw method was immersed in molten salt, and the compressive stress layers 30U and 30B having a thickness of about 40 µm on both surfaces. Formed. Here, the glass composition of the plate glass is to contain 63.5% by weight of SiO _2, Al ₂ O ₃ to 8.2 wt%, 8.0 wt.% Li ₂ O, 10.4% by weight of Na ₂ O, 11.9% by weight of ZrO _2. In the ion exchange treatment, a mixed salt of potassium nitrate and sodium nitrate (mixing ratio in weight%, potassium nitrate: sodium nitrate = 60: 40) is used as the molten salt, and the thickness of the compressive stress layers 30U and 30B is Immersion time was adjusted suitably in the state which kept the temperature of molten salt in the range of 320 degreeC-360 degreeC so that it might become thickness.

Next, the negative resist film (30 micrometers in thickness) which has hydrofluoric acid resistance was formed in the both surfaces of the ion-exchanged plate-shaped glass, and the resist film was baked at 150 degreeC for 30 minutes. Next, after the photoresist film is exposed using a mask, and developed using the developing solution (Na ₂ CO ₃ solution), removing the resist film portion was subjected to patterning treatment to form an opening.

Next, the plate-shaped glass on which the patterned resist film was formed was immersed in the etching solution containing hydrofluoric acid and hydrochloric acid, and the plate-shaped glass was cut by wet etching from both surfaces. Thereafter, the resist film was dissolved and removed with an organic solvent, and further washed to obtain a glass substrate 10A having a cross-sectional structure shown in FIG. 1 (vertical: 90 mm x 45 mm). As a result of observing the end surface 40A of the obtained glass substrate 10A with a scanning electron microscope (SEM), the specific surface properties such as the cutting surface formed by microcracks or scribe cutting or the polishing surface formed by polishing treatment were completely absent. It was not observed and it was confirmed that the front surface is an extremely smooth surface. Moreover, when the inclined surface 44U of the end surface 40A was measured by AFM (atomic force microscope) (contact mode, measuring area: 5 micrometers x 5 mm), surface roughness Ra was about 2 nm.

(Comparative Example 1)

The glass substrate 10A produced in Example 1 was subjected to the step of forming the resist film, patterning, and cutting by wet etching in the same manner as in Example 1 without performing ion exchange treatment on the plate glass used in Example 1. Plate-like glass of the same size as). Next, the plate-shaped glass was subjected to ion exchange treatment under substantially the same conditions as in Example 1 so that the thickness of the compressive stress layer except near the edges was about the same as that of the glass substrate 10A produced in Example 1. As a result, a glass substrate 200 having a cross-sectional structure shown in FIG. 2 was obtained.

(Comparative Example 2)

The plate-shaped glass used in Example 1 was scribe cut | disconnected without ion-exchange treatment, and plate-shaped glass of the same size as the glass substrate 10A produced in Example 1 was obtained. Next, the plate-shaped glass was subjected to ion exchange treatment under substantially the same conditions as in Example 1 so that the thickness of the compressive stress layer except near the edges was about the same as that of the glass substrate 10A produced in Example 1. As a result, a glass substrate 210 having a cross-sectional structure shown in FIG. 3 was obtained.

<Evaluation>

Impact resistance evaluation and visual evaluation of four corner parts were performed using the glass substrate obtained by each Example and the comparative example. The results are shown in Table 1.

Example 1 Comparative Example 1 Comparative Example 2 Impact resistance rating A B B Visual assessment of four corners A C A

In addition, the evaluation method and evaluation criteria of the impact resistance evaluation and visual evaluation of four corner parts which are shown in Table 1 are as follows.

Impact resistance evaluation

For 30 glass substrates, a drop test was conducted in which the three edges of the glass substrate were directly below, dropping from a position of 10 cm onto the floor where the hard tiles were laid. Evaluated. Evaluation criteria are as follows.

A: The breakage rate is 5% or less.

B: The breakage rate exceeds 5% and is 20% or less.

C: The breakage rate exceeds 20%.

Visual assessment of four corners

A glass substrate was placed on the surface of the liquid crystal monitor for a mobile phone with the cover glass removed, and visual evaluation was performed to compare the appearance of the image at the corner portion of the glass substrate with the appearance of the image at the center portion of the glass substrate. . Evaluation criteria are as follows.

A: There is almost no difference in appearance at the four corner parts and the center part.

B: The shape of the four corner parts is slightly distorted compared to the shape of the center part.

C: The shape of the four corner parts is markedly distorted compared to the shape of the center part.

10, 10A, 10B, 10C: glass substrate 12: plate glass
20: major surface 20U: surface
20B: Back surface 30U, 30B, 32, 34: Compression stress layer
40, 40A, 40B: end face 42: top
44U, 44B, 44U1, 44B1: slope 46: end face
48: Flat surface (grinding surface) 50, 50U, 50B, 52U, 52B: Corner part
60: decorating layer 70, 70U, 70B: etching resistant film
72, 72U, 72B: opening 100: touch panel
102: first transparent conductive film 104: spacer
106: second transparent conductive film 108: resin film layer
108A: surface 110: image display device
112: panel frame 112S: side
114: Image display panel 114A: Image display surface
120: mobile phone 122: main body
124: display unit 124A: image display surface
126: hinge portion 200, 210: glass substrate

Claims (15)

A glass substrate of a cover glass for a portable electronic device having a front surface, a back surface, and an end surface, and at least a part of the end surface formed by etching;
Each of the surface and the back surface has a compressive stress layer by an ion exchange method such that the thicknesses of the layers are equal to each other at the central portion in the surface direction at the surface and the back surface and at the end portions in the surface direction at the surface and the back surface. The glass substrate of the cover glass for portable electronic devices characterized by the above-mentioned. The glass substrate of the cover glass for portable electronic device according to claim 1, wherein the region on the center side in the thickness direction of the glass substrate on the end surface is a region forming a flat surface formed by polishing. The glass substrate of the cover glass of a portable electronic device according to claim 1, wherein the end surface comprises a region forming a flat surface formed by the polishing process and a region forming a curved surface having a surface roughness Ra of 10 nm or less. . The glass substrate of the cover glass of claim 1, wherein the end surface is a mirror surface. The glass substrate of the cover glass for portable electronic device according to any one of claims 1 to 4, wherein at least one decorative layer is provided on at least one surface selected from the front surface and the back surface. The glass substrate of the cover glass for portable electronic devices according to any one of claims 1 to 4, wherein the glass substrate is used in at least one embodiment selected from a display panel protective cover glass and a touch panel. The compressive stress layer formed by the ion exchange method is provided only on the front side and the back side,
The end surface is convex,
A glass substrate of a cover glass for a portable electronic device, wherein the surface roughness Ra of the end surface is 10 nm or less. The compressive stress layer formed by the ion exchange method is provided only on the front side and the back side,
A glass substrate of a cover glass for a portable electronic device, characterized in that at least a portion of the end surface is an area forming a flat surface formed by polishing. An image display panel having a rectangular image display area;
The cover for a portable electronic device according to any one of claims 1 to 8, which is provided on the image display surface side of the image display panel and has a plane shape substantially coincident with the contour shape in the plane direction of the image display area. An image display device for a portable electronic device, characterized by comprising at least a cover glass for a portable electronic device composed of a glass substrate of glass. An image display panel,
A portable type comprising at least a cover glass for a portable electronic device comprising a glass substrate of the cover glass for a portable electronic device according to any one of claims 1 to 8, provided on the image display surface side of the image display panel. Electronics. The portable electronic device according to claim 10, which is a mobile phone. An ion exchange treatment step of performing ion exchange treatment by bringing a plate-like glass containing at least one alkali metal into contact with a molten salt containing at least one alkali metal,
An etching-resistant film forming step of forming an etching-resistant film on at least one of the surface and the back surface of the plate-shaped glass after the ion exchange treatment;
A patterning step of patterning the etching film at least in the above-mentioned;
A glass substrate is produced by at least a cutting process of cutting the plate-like glass, which has been ion-exchanged, into small pieces, by etching the surface of the plate-shaped glass that has been subjected to the ion exchange treatment, on which the patterned inner etching film is provided, in contact with an etching solution. Glass substrate manufacturing method of cover glass for portable electronic devices. A plate-shaped glass comprising at least one alkali metal, wherein the etching glass is formed on at least one of the surface and the back surface of the plate-shaped glass which has undergone an ion exchange treatment process by contact with a molten salt containing at least one alkali metal. Etching-resistant film forming process,
A patterning step of patterning the etching film at least in the above-mentioned;
A glass substrate is produced by at least a cutting process of cutting the plate-like glass, which has been ion-exchanged, into small pieces, by etching the surface of the plate-shaped glass that has been subjected to the ion exchange treatment, on which the patterned inner etching film is provided, in contact with an etching solution. Glass substrate manufacturing method of cover glass for portable electronic devices. The decorative layer according to claim 12 or 13, wherein at least one of the decorative layers on at least one of the front and back surfaces of the plate-like glass that has been ion-exchanged after the ion exchange treatment step and before the etching-resistant film forming step is performed. The glass substrate manufacturing method of the cover glass for portable electronic devices characterized by the above-mentioned. The method of manufacturing a glass substrate of a cover glass for a portable electronic device according to claim 12 or 13, further comprising an end surface polishing step of polishing at least a part of the cut surface formed through the cutting process.

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