WO2018116981A1

WO2018116981A1 - Cover member, manufacturing method therefor, and mobile information terminal

Info

Publication number: WO2018116981A1
Application number: PCT/JP2017/045104
Authority: WO
Inventors: 諭金杉; 麻耶波田野
Original assignee: 旭硝子株式会社
Priority date: 2016-12-19
Filing date: 2017-12-15
Publication date: 2018-06-28
Also published as: JP2020024477A

Abstract

A cover member for protecting an object to be protected, wherein a first recess is provided on a first main surface of the cover member, a second recess is provided on a second main surface at a position corresponding to the first recess, and the first recess is equipped with a first bottom surface section formed in a curved shape. Thus, excellent design properties can be provided, various devices such as sensors can easily be incorporated, and the position thereof can easily be recognized.

Description

Cover member, method for manufacturing the same, and portable information terminal

The present invention relates to a cover member, a manufacturing method thereof, and a portable information terminal.

In recent years, a method of using a fingerprint for personal authentication is actively used as an advanced security measure in electronic devices. The fingerprint authentication method uses optical, thermal, pressure, capacitive, and ultrasonic sensors. However, from the viewpoint of sensing sensitivity and power consumption, capacitive and ultrasonic methods. The sensor is said to be excellent.

For example, a capacitance type sensor detects a local change in capacitance at a site where an object to be detected approaches or comes into contact. A general electrostatic capacity type sensor measures the distance between an electrode arranged in the sensor and an object to be detected based on the size of the electrostatic capacity. The ultrasonic sensor can detect an object to be detected in three dimensions by using ultrasonic waves. This method is expected as a biometric authentication sensor that can detect a foreign substance such as a liquid by transmitting it and improve security. Since the fingerprint authentication function using such a sensor is small and light and has low power consumption, it is particularly mounted on a personal information terminal (PDA) such as a smartphone, a mobile phone, or a tablet personal computer. Usually, in order to protect a fingerprint authentication sensor (hereinafter, sometimes simply referred to as a sensor), a cover member is disposed above the sensor.

Normally, a protective cover is arranged on the top of the sensor to protect the capacitive sensor. For example, in the capacitive sensor packaging of Patent Document 1, it is disclosed that a hole is provided in a cover member that allows a sensor to detect an object, and a sensor cover is disposed in the hole.

In Patent Document 2, as a cover member for a portable device, a concave portion for allowing a user to recognize a character or a figure is formed on the main surface of the cover member. Here, the visibility of the recess is improved by increasing the haze value (cloudiness) of the recess. Further, the surface roughness Ra of the recesses is made larger than the surface roughness Ra of the main surface flat portion. Thereby, the tactile sensation for recognizing the concave portion is improved by the difference in touch between the concave portion and the main surface flat portion.

International Publication No. 2013/173773 Japanese Unexamined Patent Publication No. 2013-137383

However, in the configuration in which a hole is provided in the cover member and the sensor cover is disposed in the hole as in the invention described in Patent Document 1, a jig or the like for fixing the sensor cover to the hole is required. As a result, the assembly process becomes complicated. Moreover, since a different material such as a sensor cover is required in addition to the cover member, it is difficult to achieve a material sense of unity and the design is poor.

Further, for example, in the cover member for a portable device disclosed in Patent Document 2, it is disclosed that a recess is formed on the surface of the cover member, but the surface of the recess is roughened so that a user can recognize characters or figures. It is not intended to place the sensor on the opposite surface of the recess. Temporarily, in the cover member for portable devices of patent document 2, when a sensor is arrange | positioned in the position corresponding to a recessed part, since the haze value of a recessed part is high and the surface roughness Ra of a recessed part is large, a problem arises. That is, since the surface of the recess is rough, the distance between the sensor electrode and the object to be detected becomes non-uniform and the detected capacitance becomes non-uniform. In this case, the sensor sensitivity is lowered, and there is a possibility that a desired function cannot be exhibited.

An object of the present invention is to provide a cover member that is excellent in design and that can easily incorporate various devices such as sensors and that can easily recognize the position thereof, a portable information terminal having the cover member, and a method of manufacturing the cover member. There is.

The cover member of the present invention is a cover member that protects an object to be protected, the first main surface of the cover member being provided with a first recess, and the first recess on the second main surface. A second recess is provided at a corresponding position, and the first recess has a first bottom surface formed in a curved shape.
According to the present invention, when a device such as a sensor is arranged in the second recess, the device can be protected by a portion sandwiched between the first recess and the second recess. Thus, it is possible to realize a cover member that is uniform in material and has a sense of unity and is excellent in design without using different materials such as the above. Moreover, since the number of members is small and the assembly process can be simplified, the cost can be reduced. Further, when a device such as a sensor is disposed in the second recess, the first recess facing the second recess is provided on the surface of the cover member, so that the position of the device can be easily detected visually or by touch. Can be recognized. In particular, since the first bottom surface portion in the first recess is formed in a curved shape, the position of the device can be easily detected by tactile sensation as compared to the case where the first bottom surface portion is formed in the same plane as the first main surface. Can be recognized. In addition, since it is not necessary to roughen the first recess in order for the user to recognize a device such as a sensor, the distance between the sensor electrode and the object to be detected can be made uniform, and a decrease in sensor sensitivity can be suppressed.

In the cover member of the present invention, the first bottom surface portion has a curved surface shape protruding toward the first main surface side, and the first recess portion includes an opening edge of the first recess portion and the first recess portion. It is preferable that a first connection surface portion that connects the outer edge of the bottom surface portion is provided.
In the cover member of the present invention, it is preferable that the first bottom surface portion has a curved surface shape protruding toward the second main surface side.
In this aspect of the present invention, the user's finger can be in close contact with the first bottom surface, and the uncomfortable feeling during device recognition can be reduced.

In the cover member of the present invention, a straight line connecting both ends of the first bottom surface portion in a cross-sectional view in the thickness direction of the cover member is a first reference line L1 and the first reference line L1 farthest from the first reference line L1. When the point on the bottom surface of 1 is the first point A1, it is preferable that the distance H1 from the first reference line L1 to the first point A1 is 5 μm or more.
In the above aspect of the present invention, the user can easily come into contact with the first bottom surface portion, and the position of the apparatus can be recognized more easily.
In the cover member of the present invention, a straight line connecting both ends of the first bottom surface portion in a cross-sectional view in the thickness direction of the cover member is a first reference line L1 and the first reference line L1 farthest from the first reference line L1. When the point on the bottom surface of 1 is the first point A1, and the point corresponding to the first point A1 in the second recess is the corresponding point B2, the first point from the first main surface The absolute value of the difference between the depth J1 up to A1 and the depth J2 from the second main surface to the corresponding point B2 is preferably 0.1 μm or more.

In the cover member of the present invention, it is preferable that a curved second bottom surface portion is provided at a position corresponding to the first bottom surface portion in the second recess.
In the cover member of the present invention, the second bottom surface portion has a curved shape protruding toward the second main surface side, and the second recess portion includes an opening edge of the second recess portion and the second recess portion. It is preferable to include a second connection surface portion that connects the outer edge of the bottom surface portion.
In the cover member of the present invention, it is preferable that the second bottom surface portion has a curved surface shape protruding toward the first main surface side.

In the above aspect of the present invention, if the shape of the second recess is formed symmetrically with the first recess with respect to the center in the thickness direction of the cover member, the first main surface side, the second main surface It can be protected in the same way regardless of which side the protection object is provided, and management and installation work of the cover member becomes easy.
In the cover member of the present invention, a straight line connecting both ends of the second bottom surface portion in a cross-sectional view in the thickness direction of the cover member is a second reference line L2 and the second reference line L2 farthest from the second reference line L2. 2 is a second point A2, it is preferable that a distance H2 from the second reference line L2 to the second point A2 is 5 μm or more.

In the cover member of the present invention, a second bottom surface portion protruding in a curved shape in the same direction as the first bottom surface portion is formed at a position corresponding to the first bottom surface portion in the second recess, It is preferable that a thin part is comprised by the area | region pinched | interposed by the said 2nd bottom face part and said 1st bottom face part.
In this aspect of the present invention, the tangent lines at the portion where the first bottom surface portion and the second bottom surface portion overlap with each other are substantially parallel and fall within a certain range of the thickness of the thin portion. Therefore, for example, when a capacitive sensor is arranged, good sensing sensitivity can be obtained.

In the cover member of the present invention, it is preferable that the first recess overlaps the second recess in a plan view of the cover member.
In this aspect of the present invention, when chemically strengthening the glass substrate provided with the first concave portion and the second concave portion, only the shapes of the first and second concave portions in a plan view are formed in an appropriate positional relationship. Thus, a cover member having a curved first surface is obtained.

In the cover member of the present invention, it is preferable that the distance between the center of gravity of the first recess and the center of gravity of the second recess in a plan view of the cover member is 100 μm or less.
In this aspect of the present invention, the positional deviation of the first and second recesses in plan view is reduced, and a good appearance can be obtained.

In the cover member of the present invention, it is preferable that the potassium ion concentration in the first main surface and the second main surface is higher than the potassium ion concentration in the center in the thickness direction of the cover member.
According to this aspect of the present invention, a cover member having high strength can be obtained.

The cover member of this invention WHEREIN: It is preferable that the said protection object is a portable information terminal.
The portable information terminal of the present invention has the above-described cover member.
According to the above aspect of the present invention, a portable information terminal protected by a cover member can be obtained.

The cover member manufacturing method of the present invention is a cover member manufacturing method for manufacturing a cover member that protects an object to be protected from a glass substrate, and the first concave portion is formed on the first main surface of the glass substrate. Forming a second recess at a position corresponding to the first recess on the second main surface, chemically strengthening the glass substrate on which the first recess and the second recess are formed, and the recess When the first concave portion is formed, the first concave portion includes a flat first bottom surface portion, the second concave portion is provided at a position corresponding to the first bottom surface portion, and the first bottom surface portion is formed. A planar second bottom surface portion constituting a thin portion is formed by a region sandwiched between the first portion and the second concave portion, and the processing is performed so that the first concave portion overlaps the second concave portion in plan view.

The cover member manufacturing method of the present invention is a cover member manufacturing method for manufacturing a cover member that protects an object to be protected from a glass substrate, and the first concave portion is formed on the first main surface of the glass substrate. Forming a second recess at a position corresponding to the first recess on the second main surface, chemically strengthening the glass substrate on which the first recess and the second recess are formed, and the recess When the first recess is formed, the first recess has a planar first bottom surface portion, and a first connection surface portion that connects the opening edge of the first recess and the outer edge of the first bottom surface portion. The second recess is provided at a position corresponding to the first bottom surface portion, and a planar second bottom surface portion constituting a thin portion by a region sandwiched between the first bottom surface portion and A second contact connecting the opening edge of the second recess and the outer edge of the second bottom surface portion. And a surface portion, and performs the first depth of the depth and the second bottom surface portion of the bottom portion is different so treated.
According to the above aspect of the present invention, it is possible to obtain a cover member in which the first and second bottom surface portions are curved in a curved shape on the first main surface side or the second main surface side only by chemically strengthening the glass substrate. It is done.

The cover member manufacturing method of the present invention is a cover member manufacturing method for manufacturing a cover member that protects an object to be protected from a glass substrate, and the first concave portion is formed on the first main surface of the glass substrate. The second recess is formed at a position corresponding to the first recess on the second main surface, and the first recess protrudes toward the first main surface when the recess is formed. A first bottom surface having a curved shape, wherein the second recess is formed in a curved shape protruding toward the first main surface at a position corresponding to the first bottom surface; The processing is performed so as to include a second bottom surface portion that constitutes a thin-walled portion by a region sandwiched between the portions.
According to this aspect of the present invention, it is possible to obtain a cover member in which the first and second bottom surface portions are curved in a curved shape toward the first main surface without chemically strengthening the glass substrate.

The structure of the cover member which concerns on one Embodiment of this invention is shown, (A) is sectional drawing of thickness direction, (B) is a top view from the 1st main surface side, (C) is the 2nd main surface. The top view from the side. FIG. 2A is a cross-sectional view taken along line IIA-IIA in FIG. 1B, and FIG. 2B is a cross-sectional view taken along line IIB-IIB in FIG. Sectional drawing of the cover member which has arrange | positioned the sensor. (A) is sectional drawing of the cover member in another example, (B) is sectional drawing of the cover member which has arrange | positioned the sensor in another example. (A), (B) is sectional drawing of the cover member which has arrange | positioned the sensor in another example, respectively. (A)-(C) are sectional views of a cover member in still another example. It is explanatory drawing of the manufacturing method of a cover member, (A) The top view from the 1st main surface side of a cover member, (B) is a top view of the 1st, 2nd mask member, (C) is flat form Sectional drawing of the cover member provided with this thin part. The figure which shows each CS-DOL profile at the time of chemically strengthening on different conditions. The figure which shows the CS-DOL profile at the time of implementing a two-step chemical strengthening on different conditions. Explanatory drawing of how to obtain intersection Q. Sectional drawing of the cover member integrated in the housing | casing. The cover member which gave the glare-proof process layer is shown, (A) is a top view, (B) is sectional drawing which follows the BB line, (C) is sectional drawing of the other example which follows the BB line. The cover member of the other example which gave the glare-proof process layer is shown, (A) is a top view, (B) is sectional drawing which follows the BB line, (C) is another example along the BB line. Sectional drawing. FIGS. 4A to 4D are cross-sectional views of cover members each provided with a fingerprint-proof coating layer. FIGS. 4A to 4D are cross-sectional views of cover members of other examples each provided with a fingerprint-proof coating layer. (A), (B) is sectional drawing of the cover member in which the printing layer was provided, respectively. The top view of the glass substrate from which a some cover member is obtained. (A) is an enlarged view of the XVIIIA part of FIG. 17, (B) is an enlarged view of the XVIIIB part. (A) is a top view of a glass substrate, (B) is a top view of the 1st, 2nd mask member of another example. (A) is a top view of the 1st, 2nd mask member of further another example, (B) is a glass substrate top view obtained by the process using the 1st, 2nd mask member of (A). The top view of the glass substrate of another example. (A)-(D) are explanatory drawings of the order which forms a printing layer in the cover member in Example 3, and is the figure which looked at the cover member from the 2nd main surface side. Sectional drawing of the portable information terminal in Example 6. FIG. FIGS. 7A to 7D are cross-sectional views of cover members of Examples 1 to 4 before a chemical strengthening simulation in Example 7. FIGS. Sectional drawing of the cover member after the chemical strengthening simulation in Example 7. FIG.

Hereinafter, one embodiment of the present invention will be described, but the present invention is not limited to the following embodiment. Various modifications and substitutions can be made to the following embodiments without departing from the scope of the present invention.

(Configuration of cover member)
The cover member which concerns on this embodiment is used in order to protect arbitrary protection objects. Hereinafter, the protection target of the cover member will be described as being a mobile information terminal such as a smartphone, but any target can be applied as the protection target. For example, the present invention can be applied to a display device combined with a display panel such as a liquid crystal panel or an EL panel. In particular, it is also excellent as a method for efficiently producing a large cover member for a vehicle-mounted display.

As shown in FIGS. 1 (A) to 1 (C), the cover member 1 of the present embodiment is a substantially flat rectangular parallelepiped as a whole, and includes a first main surface 3 on the upper side of FIG. 1 and the second main surface 5 on the lower side of FIG. In the present embodiment, the first main surface refers to an outer surface of an assembly (assembly) including the cover member 1, that is, a surface that can be touched by a user in a normal use state. The second main surface means an inner surface of the assembly, that is, a surface that cannot be touched by the user in a normal use state. In the following description, the longitudinal direction of the cover member 1 is the X direction, the short direction is the Y direction, and the thickness direction is the Z direction.
The cover member 1 may be glass having one or more bent portions. Further, the first main surface may be a surface that cannot be touched by the user, and the second main surface may be a surface that can be touched by the user.

The first main surface 3 of the cover member 1 is provided with at least one first recess 7. A second recess 14 is provided at a position corresponding to the first recess 7 in the second main surface 5 of the cover member 1. 1A to 1C show an example in which the first and second

main surfaces

3 and 5 of the cover member 1 are provided with one first and second

concave portions

7 and 14, respectively. It is shown. The first and

second recesses

7 and 14 are formed in the vicinity of the end portion of the cover member 1 in the X direction and in the vicinity of the center portion in the Y direction. The first and

second recesses

7 and 14 are formed in an oval shape whose length in the Y direction is longer than that in the X direction when viewed from the −Z direction and the + Z direction, respectively.
The positions where the first and

second recesses

7 and 14 are formed are such that they face each other in the Z direction (overlapping in the XY plane, that is, the first recess 7 and the second recess 14 are in plan view). As long as they are overlapped), they can be set at any position. The distance between the position of the center of gravity of the first recess 7 and the position of the center of gravity of the second recess 14 in plan view of the cover member 1 is set so that the positional deviation between the first and

second recesses

7 and 14 becomes inconspicuous. 100 μm or less is preferable. When the cover member 1 has one or more bent portions, the first and second

concave portions

7 and 14 may be formed in the bent portion. The number and shape of the first and

second recesses

7 and 14 are also arbitrary.

As shown in FIGS. 2A and 2B, the first concave portion 7 includes a first bottom surface portion 8 projecting in a curved shape on the first main surface 3 side, and an opening of the first concave portion 7. A first connection surface portion 11 that connects the edge and the outer edge of the first bottom surface portion 8 is provided. In addition, when the 1st recessed part 7 is provided with the 1st connection surface part 11, the outer edge of the 1st bottom face part 8 is the 2nd main surface in the part which protrudes in the 1st main surface 3 side in sectional view. It is a part located on the 5 side. The first bottom surface portion 8 is an oval region, and the first connection surface portion 11 is an oval region surrounding the first bottom surface portion 8. The first connection surface portion 11 has a curved surface shape (R shape) that smoothly connects the first bottom surface portion 8 and the first main surface 3.

It is preferable that the curvature radius of the first connection surface portion 11 increases from the first bottom surface portion 8 side toward the opening edge side of the first recess 7. With this configuration, the stress concentration at the connection portion between the first bottom surface portion 8 and the first connection surface portion 11 is relaxed, and the strength is improved. In particular, when the fingerprint authentication sensor 40 (sensor 40) is disposed in the second recess 14 (see FIG. 3), the finger is pressed against the thin portion 21 each time authentication is performed. Since a repetitive force is applied, there is an effect of suppressing stress concentration in that portion in terms of shape.

The second concave portion 14 constitutes a curved second bottom surface portion 15 that protrudes toward the first main surface 3 side. The second bottom surface portion 15 includes a second thin portion constituting portion 16 and a second connecting portion constituting portion 17. The second thin portion constituent portion 16 is provided so as to overlap the first bottom surface portion 8 in plan view, and is formed in a curved shape corresponding to the first bottom surface portion 8. The second connection part component part 17 is provided so as to overlap the first connection surface part 11 in plan view, and connects the outer edge of the second thin part component part 16 and the outer edge of the second bottom surface part 15. Note that the second thin portion constituting portion 16 is a portion overlapping the outer edge of the first bottom surface portion 8 in plan view.

By providing the first and

second recesses

7 and 14 as described above, the cover member 1 is formed with a thin portion 21, a thick portion 22, and a connection portion 23. The thin portion 21 is a curved plate-like portion sandwiched between the first bottom surface portion 8 and the second thin portion constituent portion 16. The thick portion 22 is a portion that is sandwiched between regions of the first and second

main surfaces

3 and 5 where the first and

second recesses

7 and 14 are not provided. The connecting portion 23 is a region sandwiched between the first connecting surface portion 11 and the second connecting portion constituting portion 17 and is a portion connecting the thin portion 21 and the thick portion 22.

When such a cover member 1 is incorporated in a housing or the like in order to protect an arbitrary surface (for example, the front surface or the side surface) of a portable information terminal or a display device, a sensor for fingerprint authentication or the like is provided in the second recess 14. Since various devices such as a display panel such as a liquid crystal panel and an organic EL panel, illumination, and a camera can be arranged, space efficiency can be improved. Examples of sensors include biometric sensors such as fingerprints, irises, and veins. Capacitance type, optical type, infrared type, and ultrasonic type sensors are known as sensing methods. A sensor etc. are mentioned. Here, since the device incorporated in the second recess 14 is protected by the thin portion 21 facing in the Z direction, the material can be used without using a different material such as a sensor cover unlike the invention of Patent Document 1 described above. Therefore, it is possible to realize the cover member 1 having a uniform and uniform design and excellent design. Further, since the number of members is small and the assembly process can be simplified, there is a great effect in cost reduction. Furthermore, since the opening of the cover member for incorporating another member can be reduced, waterproof and drip-proofing can be easily provided. Furthermore, since the thick wall portion 22 has a planar shape, the thin wall portion 21 is recessed as viewed from the front surface side, so that the user of the portable information terminal can determine the position of the thin wall portion 21 and the thin wall portion 21. The positions of various devices on the back side can be easily recognized by visual or tactile senses. In particular, since the first bottom surface portion 8 of the first recess 7 is formed in a curved shape protruding toward the first main surface 3, the positions of various devices can be easily recognized by tactile sensation.

The first and

second recesses

7 and 14 are provided by a machining process such as grinding or a molding process such as hot pressing or vacuum forming, but are preferably provided by etching. According to the etching, fine scratches and defects are removed, and the strength of the cover member 1 is improved. Moreover, according to the etching, it is easy to control the thickness of the thin portion 21 in the Z direction, and it is completed in one step.
The curved plate-like thin portion 21 sandwiched between the first and second

bottom surface portions

8 and 15 is provided by mechanical processing such as grinding, but is preferably provided by chemical strengthening. According to the chemical strengthening, the thin wall portion 21 is warped by utilizing the surface expansion caused by the shape difference between the first and second

concave portions

7 and 14, and the first and second

bottom surface portions

8 and 15 are easily curved. Can be formed.

As shown in FIG. 3, the connecting portion P1 between the first concave portion 7 and the first main surface 3 and the connecting portion P2 between the second concave portion 14 and the second main surface 5 are also smoothly continuous curved surfaces. It is preferable to make it into a shape. By making the connecting portions P1 and P2 into a curved surface without edges, there is an effect of making it difficult to cause chipping or breakage due to dropping or contact with an external hard member. In order to make the connecting portions P1 and P2 have a smoothly continuous curved surface shape, the connecting portions P1 and P2 are finished by buffing or the like after the first and second

concave portions

7 and 14 are formed. However, when the first and

second recesses

7 and 14 are provided by wet etching, the time until the glass substrate is separated from the etchant and the mask is peeled and cleaned after the etching process is maintained longer than usual. In addition, the connecting portions P1 and P2 can be smoothly curved. The etchant remains due to surface tension at the boundary between the first and

second recesses

7 and 14 formed by etching and the mask, and the first and

second recesses

7 and 14 and the first and first recesses in contact with the remaining etchant. Etching proceeds slightly at the connecting portions P1 and P2 with the

main surfaces

3 and 5, so that the edges of the connecting portions P1 and P2 become smooth continuous curved surfaces. The holding time for this is adjusted between several seconds to several tens of minutes depending on the etchant used and the etching resistance of the glass substrate.

Of the first and

second recesses

7 and 14, it is preferable that the first recess 7 with which the finger is brought into contact has the first connecting surface portion 11 as a smooth curved surface as described above. As shown in FIG. 4A, the first recess 7A is composed of a first bottom surface portion 8A and a planar first connection surface portion 11A extending in the Z direction (perpendicular to the XY plane). The two concave portions 14A may be constituted by a curved second bottom surface portion 15A corresponding to the first bottom surface portion 8A and a planar second connection surface portion 18A extending in the Z direction. In that case, the first connecting surface portion 11A and the first main surface 3 are connected to each other vertically, and the second connecting surface portion 18A and the second main surface 5 are also connected to each other vertically.
A portion sandwiched between the first bottom surface portion 8A and the second bottom surface portion 15A constitutes a thin portion 21A. A portion sandwiched between regions where the first and second

concave portions

7A and 14A are not provided in the first and second

main surfaces

3 and 5 constitutes a thick portion 22A.
The height T1 of the first connection surface portion 11A and the height T2 of the second connection surface portion 18A may be the same.

When the sensor 40 is disposed in the second recess 14 as in the present embodiment, the arithmetic average roughness Ra of the first bottom surface portion 8 constituting the thin portion 21 is preferably 50 nm or less, and more preferably 45 nm or less. Preferably, it is 30 nm or less. As shown in FIG. 3, the sensor 40 such as a capacitive sensor or an ultrasonic sensor is disposed in the second recess 14 (the second bottom surface portion 15 constituting the thin portion 21) via the adhesive layer 41. At the same time, an object to be detected (for example, a finger) in contact with the first bottom surface portion 8 is detected. When the sensor 40 is fixed to a housing or the like, the adhesive layer 41 may not be provided. Therefore, it is preferable that the arithmetic average roughness Ra of the first bottom surface portion 8 is 50 nm or less because the sensing sensitivity is increased because the arithmetic average roughness Ra is sufficiently smaller than the degree of unevenness of the fingerprint of the finger. Further, in such a configuration, the user of the display device or the portable information terminal uses the first recess 7 to detect the position of the thin portion 21 and the sensor 40 disposed on the second recess 14 side of the thin portion 21. The position can be easily recognized visually or by touch. Further, the lower limit of the arithmetic average roughness Ra of the first bottom surface portion 8 is not particularly limited, but is preferably 2 nm or more, and more preferably 4 nm or more. The arithmetic average roughness Ra of the first bottom surface portion 8 can be adjusted by selection of polishing abrasive grains, a polishing method, and the like.
The arithmetic average roughness Ra can be measured based on Japanese Industrial Standard JIS B0601.

As shown in FIG. 3, when the sensor 40 is disposed in the second recess 14 via the adhesive layer 41, it is preferable that the back surface of the sensor 40 does not protrude from the second main surface 5. In this case, the adhesive layer 41 and the sensor 40 are housed in the second recess 14 and can be easily combined with the protection target.

The arithmetic average roughness Ra of the second bottom surface portion 15 constituting the thin wall portion 21 is more preferably 50 nm or less, more preferably 45 nm or less, and even more preferably 30 nm or less, like the first bottom surface portion 8. . When the arithmetic average roughness Ra of the second bottom surface portion 15 is 50 nm or less, it is preferable in that the sensitivity is sufficiently smaller than the degree of unevenness of the fingerprint of the finger and the sensing sensitivity is increased.

Further, as shown in FIG. 3, the straight line connecting both ends of the first bottom surface portion 8 in the cross-sectional view in the thickness direction of the cover member 1 is the point farthest from the first reference line L1 and the first reference line L1. When the vertex of the first bottom surface portion 8 is the first point A1, the distance H1 from the first reference line L1 to the first point A1 is preferably 5 μm or more. By setting the distance H1 to 5 μm or more, the user can easily recognize the first bottom surface portion 8. Moreover, it is preferable that the vertex (1st point A1) of the 1st bottom face part 8 is located below the 1st main surface 3 (cover member inside side).
Furthermore, when the point on the second bottom surface portion 8 corresponding to the first point A1 (located on the opposite side of the first point A1 in the thin portion 21) is the corresponding point B2, the first main surface 3 The absolute value of the difference between the depth J1 from the first principal point A1 to the depth J2 from the second principal surface 5 to the corresponding point B2 is preferably 0.1 μm or more. The absolute value of the difference between the depth J1 and the depth J2 is more preferably 0.2 μm or more, and even more preferably 0.5 μm or more. As a result, the thin-walled portion 21 has a curved surface due to chemical strengthening described later, and the user can easily determine the position only by touch.

Further, as shown in FIG. 4B, the configuration shown in FIG. In this configuration, the first bottom surface portion 8B, the first thin portion constituent portion 9B, and the first connecting portion constituent portion 10B of the first concave portion 7B are the same as the second bottom portion 15 and the second thin portion in FIG. The second bottom surface portion 15B and the second connection surface portion 18B of the second concave portion 14B correspond to the first bottom surface portion 8 and the first connection portion 18B in FIG. Corresponding to the connection surface portion 11, a thin portion 21B, a thick portion 22B, and a connection portion 23B are provided. The sensor 40B is disposed on the second concave portion 14B side of the thin portion 21B.
That is, the first bottom surface portion 8B has a curved surface shape protruding toward the second main surface 5 side. Further, the second bottom surface portion 15B has a curved surface shape protruding toward the second main surface 5 side. The second recess 14B includes a second connection surface portion 18B that connects the opening edge of the second recess 14B and the outer edge of the second bottom surface portion 15B.
At this time, the second bottom surface that is the point farthest from the second reference line L2 and the second reference line L2 is a straight line connecting both ends of the second bottom surface portion 15B in the sectional view of the cover member 1 in the thickness direction. When the vertex of the part 15B is the second point A2, it is preferable that the distance H2 from the second reference line L2 to the second point A2 is 5 μm or more.

The first and second recesses need not have the same shape, and may have different areas, formations, and the like. Thereby, according to apparatus, such as a sensor arrange | positioned, the magnitude | size of a 2nd recessed part can be changed suitably.
For example, as shown in FIG. 5A, the length of the first recess 7C of the first main surface 3 in the Y direction and the X direction is set to the length of the second recess 14C of the second main surface 5 and You may make it longer than the length of a X direction, ie, the outer edge of the 1st recessed part 7C may be located outside the outer edge of the 2nd recessed part 14C in the planar view of the cover member 1. FIG.

In this case, the first concave portion 7C includes a curved first bottom surface portion 8C protruding toward the first main surface 3, the opening edge of the first concave portion 7C, and the outer edge of the first bottom surface portion 8C. 11C of 1st connection surface parts to connect are provided. The first bottom surface portion 8C includes a first thin portion constituting portion 9C located at the center of the first bottom surface portion 8C, and a first connecting portion constituting portion 10C surrounding the first thin portion constituting portion 9C. ing.
14 C of 2nd recessed parts are provided with the curved 2nd bottom face part 15C which protrudes in the 1st main surface 3 side. The second bottom surface portion 15C includes a second thin portion constituent portion 16C and a second connecting portion constituent portion 17C. The second thin portion constituting portion 16C is formed in a curved surface shape corresponding to the first thin portion constituting portion 9C.
A curved plate-like portion having a constant thickness sandwiched between the first thin portion constituting portion 9C and the second thin portion constituting portion 16C constitutes the thin portion 21C. A portion sandwiched between regions where the first and second

concave portions

7C and 14C are not provided in the first and second

main surfaces

3 and 5 constitutes a thick portion 22C. When the area | region which opposes the 1st connection part structure part 10C and the 1st connection surface part 11C in the 2nd main surface 5 is made into the 2nd recessed part opposing part 5C, the 1st connection part structure part 10C and the 1st A region sandwiched between the connecting surface portion 11C, the second connecting portion constituting portion 17C, and the second recessed portion facing portion 5C constitutes a connecting portion 23C that connects the thin portion 21C and the thick portion 22C.

In such a configuration, the dimension of the sensor 40C can be made smaller than the dimension of the first recess 7C in the Y direction and the X direction. Here, the sensor 40C includes a sensor main body 46C that performs sensing, and a housing 47C that supports and fixes the outer periphery of the sensor main body 46C in the XY direction. Therefore, the thin part 21C can be reinforced by making the overall dimension of the sensor 40C smaller than the dimension of the first concave part 7C and disposing the sensor 40C on the second concave part 14C side of the thin part 21C.

Further, as shown in FIG. 5B, the configuration shown in FIG. 5A may be vertically inverted. In this configuration, the first concave portion facing portion 3D, the first bottom surface portion 8D of the first concave portion 7D, the first thin portion constituting portion 9D, and the first connecting portion constituting portion 10D are as shown in FIG. The second concave portion 14D corresponds to the second concave portion facing portion 5C, the second bottom surface portion 15C of the second concave portion 14C, the second thin portion constituting portion 16C, and the second connecting portion constituting portion 17C. The bottom surface portion 15D, the second thin portion constituting portion 16D, the second connecting portion constituting portion 17D, and the second connecting surface portion 18D are the first bottom face portion 8C of the first recess 7C in FIG. Corresponding to the first thin portion constituting portion 9C, the first connecting portion constituting portion 10C, and the first connecting surface portion 11C, a thin portion 21D, a thick portion 22D, and a connecting portion 23D are provided. Further, the outer edge of the first recess 7D is located inside the outer edge of the second recess 14D.

Even in such a configuration, the thin portion 21D can be reinforced by making the overall size of the sensor 40D larger than the size of the first concave portion 7D and disposing the sensor 40D on the second concave portion 14D side of the thin portion 21D. Here, the size of the sensor body 46D is preferably smaller than the overall size of the first recess 7D in order to appropriately perform sensing. That is, the overall dimension of the first recess 7D is preferably larger than the dimension of the sensor body 46D and smaller than the overall dimension of the sensor 40D.
Moreover, you may make it at least one part of the outer edge of a 1st recessed part locate inside or the outer side from the outer edge of a 2nd recessed part.

Further, as shown in FIG. 6A, the second recess 14E is composed of a planar second bottom surface portion 15E and a second connection surface portion 18E, and the first bottom surface portion 8 and the second bottom surface portion 8E. You may form the thin part 21E pinched | interposed with the bottom face part 15E. In this case, a connection portion 23E sandwiched between the first connection surface portion 11 and the second connection surface portion 18E, and a thick portion 22E composed of portions other than the thin portion 21E and the connection portion 23E are provided.
Further, as shown in FIG. 6B, the second concave portion 14F is constituted by a second bottom surface portion 15F that protrudes in a curved shape toward the second main surface 5 side, and a second connection surface portion 18F. The thin wall portion 21F sandwiched between the first bottom surface portion 8 and the second bottom surface portion 15F may be formed. In this case, a connection portion 23F sandwiched between the first connection surface portion 11 and the second connection surface portion 18F, and a thick portion 22F configured by portions other than the thin portion 21F and the connection portion 23F are provided.
Further, as shown in FIG. 6C, the first concave portion 7G is constituted by a first bottom surface portion 8G protruding in a curved shape on the second main surface 5 side, and the second concave portion 14G is formed as the first concave portion 14G. You may comprise by the 2nd bottom face part 15G which protrudes in the main surface 3 side.

Hereinafter, a preferred embodiment of the cover member will be described by exemplifying the configuration shown in FIGS. 1 and 2, but the same applies to the configurations of FIGS.
The haze value (cloudiness) of the thin-walled portion 21 is preferably 16% or less, more preferably 15% or less, and further preferably 10% or less. By setting the haze value of the thin portion 21 to 16% or less, both the surface flatness of the first and second

bottom surface portions

8 and 15 constituting the thin portion 21 and the aesthetic appearance of the cover member 1 can be achieved. That is, when the haze value of the thin portion 21 is 16% or less and the surface flatness of the first and second

bottom surface portions

8 and 15 is high, the sensor 40 is disposed in the second recess 14 as described above. Even so, the desired sensing capability can be realized. However, when a display panel is arranged in the thin portion 21, an anti-glare process described later may be performed. The haze value at this time is not limited to the above range.

Further, the surface flatness of the thin portion 21 affects the surface flatness of the printed layer when printing is performed on the second bottom surface portion 15 of the thin portion 21. By setting the haze value of the thin-walled portion 21 to 16% or less, surface flatness that does not affect the sensor sensitivity can be secured, and the aesthetics of the printed layer described later can be made excellent. On the other hand, when the haze value of the thin portion 21 is larger than 16%, the ink used for printing does not completely enter the unevenness formed on the outermost surface of the thin portion 21, and the appearance after the cover member 1 is mounted on the protection target. Deteriorate.

In addition, the haze value of the thin portion 21 is set to 16% or less, and the transmittance of the thin portion 21 is increased so that there is a sense of unity between the thin portion 21 and the thick portion 22, and the cover has excellent aesthetics as a whole. A member can be realized.

In addition, the haze value of the thick portion 22 is preferably 5% or less, more preferably 1% or less, further preferably 0.5% or less, and particularly preferably 0.2% or less. Thus, compared with the thin part 21 formed by an etching process etc., the thick part 22 has high surface flatness and transmittance | permeability. Therefore, if the haze value of the thin wall portion 21 is larger than 16%, the thin wall portion 21 becomes cloudy with respect to the thick wall portion 22 having high transmittance, and the design of the cover member 1 as a whole is deteriorated. However, when a display panel is arranged in the thick portion 22, an anti-glare process described later may be performed. The haze value at this time is not limited to the above range.
In addition, the haze value of the thin part 21 can be adjusted by the etching conditions at the time of providing the 1st, 2nd recessed

parts

7 and 14. The haze value can be measured based on Japanese Industrial Standard JIS K7136.

The cover member 1 is preferably a chemically strengthened glass. The chemically strengthened cover member 1 has high mechanical strength because the compressive stress layer is formed on the surfaces of the thin portion 21 and the thick portion 22, that is, the first and second

main surfaces

3 and 5. It is done.

Here, the internal tensile stress (CT) of the chemically strengthened glass is generally the plate thickness t, the surface compressive stress CS (Compressive Stress) of the compressive stress layer, and the depth DOL (Depth Of) of the compressive stress layer. (Layer) and the relational expression CT = (CS × DOL) / (t−2 × DOL). Therefore, in the same CS and the same DOL, the smaller the plate thickness, the larger the CT. When chemical strengthening is performed by immersing in a general alkali metal molten salt on a glass having a portion having a partially different plate thickness, such as the cover member 1 having the thin portion 21 and the thick portion 22, the first main component is obtained. Ions are exchanged isotropically from the surface 3 and the second main surface 5, and the same CS and the same DOL are obtained regardless of partial plate thickness differences. At this time, if chemical strengthening is performed under the conditions that are applied to a normal flat cover member, the CT of the thin portion 21 becomes excessively large and the risk of self-destruct destruction increases. On the other hand, if the whole is chemically strengthened under conditions matching CS and DOL so that the thin-walled portion 21 does not break, the strengthening has to be weak chemical strengthening, and the strength of the thick-walled portion 22 has the thin-walled portion 21. It is weaker than a flat cover member. Therefore, it is preferable to give CS and DOL to the thin portion 21 so that the thin portion 21 is not destroyed while giving the thick portion 22 CS and DOL equivalent to those of a normal flat cover member. That is, it is preferable that the depth of the compressive stress layer formed in the thin portion 21 is smaller than the depth of the compressive stress layer formed in the thick portion 22.

More specifically, the CS of the thick portion 22 is preferably 400 MPa or more, more preferably 500 MPa or more, further preferably 600 MPa or more, and the DOL is preferably 15 μm or more, more preferably 20 μm or more, and further preferably 25 μm. That's it. The CS of the thick portion 22 is preferably 1300 MPa or less, more preferably 1200 MPa or less, more preferably 1100 MPa or less, and the DOL is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 70 μm or less. The CS of the thin-walled portion 21 is preferably 300 MPa or more, more preferably 400 MPa or more, more preferably 500 MPa or more, and DOL is preferably 5 μm or more, more preferably 7 μm or more, and further preferably 10 μm or more. The CS of the thin wall portion 21 is preferably 1300 MPa or less, more preferably 1200 MPa or less, further preferably 1100 MPa or less, and the DOL is preferably 25 μm or less, more preferably 20 μm or less, and further preferably 15 μm or less. As a result, the thick portion 22 has the same strength as a normal flat cover member having no recess, and the thin portion 21 is given the necessary reinforcement as far as possible. In the case of the present embodiment, since the thin portion 21 is in a position recessed from the first main surface 3 and the second main surface 5, even if the device using the cover member 1 is dropped, the thin portion The probability that 21 is in direct contact with the floor (ground) is low, and even if the thin-walled portion 21 is CS or DOL lower than the thick-walled portion 22, it is difficult to break. A method for differentiating CS and DOL between the thin portion 21 and the thick portion 22 will be described later.

The cover member 1 is preferably polished on the first main surface 3 and the second main surface 5 in order to improve smoothness. For example, when a polishing slurry containing cerium oxide or colloidal silica is used as a polishing agent using a suede pad, scratches (cracks) present on the first and second

main surfaces

3 and 5 of the cover member 1 and the cover member 1 The bending and the dent can be removed, and the strength of the cover member 1 is improved. Polishing may be performed either before or after chemical strengthening of the cover member 1, but is preferably performed after chemical strengthening. This is because defects are generated on the first main surface and the second main surface of the glass plate subjected to chemical strengthening by ion exchange. In addition, fine irregularities of up to about 1 μm may remain. When a force acts on the glass plate, the stress concentrates on a location where the above-described defects or fine irregularities exist, and may break even with a force smaller than the theoretical strength. Therefore, the layer (defect layer) which has a defect and fine unevenness | corrugation which exists in the outermost surface of the glass plate after chemical strengthening is removed by grinding | polishing. The thickness of the defect layer in which defects are present is usually 0.01 to 0.5 μm although it depends on the conditions of chemical strengthening.

Note that polishing may be performed only on the thick portion 22. In this case, effects such as an improvement in sensing sensitivity and an improvement in visibility when a sensor or a display panel is disposed on the second main surface 5 side can be obtained. Moreover, since the thick part 22 is concerned with the intensity | strength of the cover member 1 whole, the intensity | strength of the cover member 1 can be improved by removing a defect by grinding | polishing. When polishing the thick portion 22 of the cover member 1 after chemical strengthening, the depth (DOL) of the compressive stress layer of the first and

second recesses

7 and 14 becomes deeper than the thick portion 22. That is, the cover member 1 that maintains the strength of the thin portion 21 is obtained.

Further, polishing may be performed on the first and second

concave portions

7 and 14. In this case, effects such as improved sensing sensitivity and improved visibility when sensors and display panels are arranged in the first and

second recesses

7 and 14 can be obtained. When the first and

second recesses

7 and 14 of the cover member 1 after chemical strengthening are polished, the depth (DOL) of the compressive stress layer of the thick portion 22 becomes deeper than that of the thin portion 21. By removing the extraneous layer formed during the formation of the first and

second recesses

7 and 14 by polishing, it becomes easy to form an antifouling layer to be described later.

Further, as described above, the cover member 1 of the present embodiment is not limited to the use for protecting a portable information terminal, but particularly when used for protecting a display device such as a portable information terminal or a display panel, the thick portion 22. The thickness in the Z direction is preferably 5 mm or less, more preferably 2 mm or less, further preferably 1.5 mm or less, and particularly preferably 0.8 mm or less. This is because if it is thicker than 5 mm, the difference in thickness from the thin portion 21 becomes large, making it difficult to process, and increasing the mass when using a portable information terminal, for example. The thickness of the thick portion 22 in the Z direction is 0.1 mm or more, preferably 0.15 mm or more, and more preferably 0.2 mm or more in order to increase the rigidity. If it is thinner than 0.1 mm, the rigidity becomes too low and there is a risk that the portable information terminal will not be used for protection.

Further, the maximum thickness in the Z direction of the thin portion 21 is 1 mm or less, preferably 0.4 mm or less, more preferably 0.35 mm or less, further preferably 0.3 mm or less, particularly preferably 0.25 mm or less. 2 mm or less is particularly preferable, and 0.1 mm or less is most preferable. In particular, when the capacitance type sensor is arranged on the second concave portion 14 side of the thin portion 21, the thinner the thin portion 21, the larger the detected capacitance and the better the sensing sensitivity. For example, in the case of fingerprint authentication that detects fine irregularities of a fingertip fingerprint, a difference in capacitance according to the fine irregularities of the fingertip fingerprint becomes large, so that detection can be performed with high sensing sensitivity. On the other hand, the lower limit of the thickness in the Z direction of the thin portion 21 is not particularly limited. However, when the thin portion 21 becomes excessively thin, the strength tends to decrease and it is difficult to exhibit an appropriate function as a protective portion such as a sensor. . Therefore, the thickness of the thin portion 21 in the Z direction is, for example, 0.01 mm or more, and preferably 0.05 mm or more.

The Z direction thickness of the thick portion 22 is preferably 10 times or less, more preferably 8 times or less, relative to the Z direction thickness of the thin portion 21. If the thickness in the Z direction of the thick portion 22 is more than 10 times the thickness of the thin portion 21 in the Z direction, it may be difficult to process. The ratio of the thickness in the Z direction of the thick portion 22 to the thickness in the Z direction of the thin portion 21 is not particularly limited and can be set according to the application. In the protection use of a portable information terminal, it is typically 1.5 times or more. The ratio of the area of the thin portion 21 to the thick portion 22 is 1/2 or less, preferably 1/3 or less, and more preferably 1/4 or less. If the ratio of the area of the thin portion 21 to the thick portion 22 is greater than ½, the strength may be significantly impaired. The thickness of the thin portion 21 in the Z direction can be measured by, for example, a laser displacement meter LT-9000 manufactured by Keyence Corporation.

The Young's modulus of the thin portion 21 is 60 GPa or more, preferably 65 GPa or more, and more preferably 70 GPa or more. When the Young's modulus of the thin-walled portion 21 is 60 GPa or more, the thin-walled portion 21 can be sufficiently prevented from being damaged due to a collision with an external collision object. Moreover, when the sensor for fingerprint authentication is arrange | positioned in the 2nd recessed part 14, damage to the thin part 21 resulting from fall or collision of a smart phone etc. can fully be prevented. Furthermore, damage to the sensor protected by the thin portion 21 can be sufficiently prevented. Moreover, although the upper limit of the Young's modulus of the thin part 21 is not specifically limited, From a viewpoint of productivity, the Young's modulus of the thin part 21 is 200 GPa or less, for example, and 150 GPa or less is preferable.

The Vickers hardness Hv of the thin portion 21 is preferably 400 or more, and more preferably 500 or more. When the Vickers hardness of the thin portion 21 is 400 or more, it is possible to sufficiently prevent the thin portion 21 from being scratched due to a collision with a collision object from the outside. Further, when the fingerprint authentication sensor is disposed in the second recess 14, it is possible to sufficiently prevent the thin-walled portion 21 from being scratched due to dropping or collision of a smartphone or the like. Furthermore, damage to the sensor protected by the thin portion 21 can be sufficiently prevented. Moreover, the upper limit of the Vickers hardness of the thin-walled portion 21 is not particularly limited, but if it is too high, polishing and processing may be difficult. Therefore, the Vickers hardness of the chemically strengthened glass is, for example, 1200 or less, and preferably 1000 or less. The Vickers hardness can be measured by, for example, a Vickers hardness test described in Japanese Industrial Standard JIS Z 2244.

The relative permittivity of the thin portion 21 at a frequency of 1 MHz is preferably 7 or more, more preferably 7.2 or more, and further preferably 7.5 or more. When the capacitance type sensor is arranged in the second recess 14 constituting the thin portion 21, the detected capacitance can be increased by increasing the relative dielectric constant of the thin portion 21, and excellent sensing sensitivity. Can be realized. In particular, when the relative permittivity of the thin-walled portion 21 at a frequency of 1 MHz is 7 or more, the capacitance corresponding to the fine irregularities of the fingerprint of the fingertip is also obtained in the case of fingerprint authentication for detecting the fine irregularities of the fingerprint of the fingertip. Because the difference between the two becomes large, detection with high sensing sensitivity is possible. Further, the upper limit of the relative dielectric constant of the thin portion 21 is not particularly limited, but if it is excessively high, the dielectric loss increases, the power consumption increases, and the reaction may become slow. Accordingly, the relative dielectric constant of the thin portion 21 at a frequency of 1 MHz is preferably 20 or less, and more preferably 15 or less. The relative dielectric constant is obtained by measuring the capacitance of a capacitance in which electrodes are formed on both surfaces of the cover member 1.

A print layer is preferably provided on the second main surface 5 of the cover member 1. In particular, it is preferable to provide a printing layer also in the second recess 14. By providing such a printed layer, the fingerprint authentication sensor disposed in the portable information terminal that is the protection target of the cover member 1 or in the second recess 14 is visually recognized through the cover member 1. It can be effectively prevented. Moreover, a desired color can be imparted and an excellent appearance can be obtained. In order to keep the capacitance of the cover member 1 (thin wall portion 21) high, the thinner the printed layer, the better. The thickness of the printing layer is preferably 30 μm or less, more preferably 25 μm or less, and even more preferably 10 μm or less. However, in white printing using an ink containing a compound having a high relative dielectric constant (for example, an ink containing TiO ₂ ), since the relative dielectric constant of the printed layer is high, the thickness of the printed layer is preferably 100 μm or less, more preferably 50 μm or less. 25 μm or less is particularly preferable.

When the printing layer is provided on the second main surface 5 of the cover member 1, a device such as a sensor is positioned on the back surface of the printing layer so as to face the second recess 14 in the Z direction (the back side of the thin portion 21). Placed in. Therefore, the arithmetic average roughness Ra of the outermost surface of the printing layer is preferably 50 nm or less, more preferably 45 nm or less, and further preferably 30 nm or less. More preferably, the arithmetic average roughness Ra of the back surface of the printing layer is also preferably 50 nm or less, more preferably 45 nm or less, and further preferably 30 nm or less. When the arithmetic mean roughness Ra of the outermost surface and the back surface of the printed layer is 50 nm or less, it is preferable in terms of increasing sensing sensitivity because it is sufficiently smaller than the degree of unevenness of the fingerprint of the finger. Further, the lower limit of the arithmetic average roughness Ra of the outermost surface and the back surface of the printing layer is not particularly limited, but is preferably 2 nm or more, more preferably 4 nm or more.

(Manufacturing method of cover member)
As shown in FIG. 7A, the cover member 1 described above has at least one first surface facing the first main surface 103 and the second main surface 105 of the glass substrate 101 having the same dimensions as the cover member 1. This is obtained by providing one recess 107 and second recess 114.

A method for manufacturing the glass substrate 101 will be described. First, the raw materials of each component are prepared so as to have the composition described later, and heated and melted in a glass melting furnace. The glass is homogenized by bubbling, stirring, adding a clarifying agent, etc., formed into a glass plate having a predetermined thickness by a known forming method, and slowly cooled. Examples of the glass forming method include a float method, a press method, a fusion method, a downdraw method, and a rollout method. In particular, a float method suitable for mass production is suitable. Further, continuous molding methods other than the float method, that is, the fusion method and the downdraw method are also suitable. The glass member formed into a flat plate shape by an arbitrary forming method is gradually cooled and then cut into a desired size (the size of the cover member 1). In addition, when more accurate dimensional accuracy is required, the glass member after cutting may be polished. As a result, a glass substrate 101 having a flat first main surface 103 and a second main surface 105 as shown in FIG. 7A and having a flat plate shape as a whole is obtained.

Subsequently, the process proceeds to a recess forming step in which at least one first recess 107 and second recess 114 facing the first main surface 103 and the second main surface 105 of the glass substrate 101 are provided. In the recess forming step, the first mask member 201 as shown in FIG. 7B is disposed on the first main surface 103 of the glass substrate 101, and the second mask member 301 is disposed on the second main surface 105. Then, the glass substrate 101 is etched.

The X direction dimension and the Y direction dimension of the first mask member 201 are set so as to cover the entire first main surface 103 of the glass substrate 101. In the example of FIG. 7B, the X direction dimension and the Y direction dimension of the first mask member 201 are substantially equal to the X direction dimension and the Y direction dimension of the glass substrate 101. Further, the first mask member 201 is provided with a first recess forming hole 207 for forming the first recess 107 in the first main surface 103 of the glass substrate 101. Therefore, the etchant reaches the first main surface 103 of the glass substrate 101 through the first recess forming hole 207, and the first recess 107 is formed as shown in FIG. In the case where the plurality of first recesses 107 are formed on the first main surface 103 of the glass substrate 101, the first mask member 201 having the plurality of first recess formation holes 207 may be used.

The X direction dimension and the Y direction dimension of the second mask member 301 are set so as to cover the entire second main surface 105 of the glass substrate 101. In the example of FIG. 7B, the X direction dimension and the Y direction dimension of the second mask member 301 are substantially equal to the X direction dimension and the Y direction dimension of the glass substrate 101. Further, the second mask member 301 is provided with a second recess forming hole 314 in the second main surface 105 of the glass substrate 101. Therefore, the etchant reaches the second main surface 105 of the glass substrate 101 through the second recess forming hole 314 and forms the second recess 114. In the case where a plurality of second recesses 114 are formed on the second main surface 105 of the glass substrate 101, the second mask member 301 having a plurality of second recess formation holes 314 may be used.

By such processing, as shown in FIG. 7C, the glass substrate 101 is provided with at least one first recess 107 and second recess 114, respectively.
The first recess 107 includes a planar first bottom surface portion 108 and a first connection surface portion 111 that connects the opening edge of the first recess 107 and the outer edge of the first bottom surface portion 108. . The second concave portion 114 includes a planar second bottom surface portion 115 provided at a position corresponding to the first bottom surface portion 108, an opening edge of the second concave portion 114, and an outer edge of the second bottom surface portion 115. And a second connection surface portion 118 for connecting the two.
A flat thin portion 121 is formed in a region sandwiched between the first bottom surface portion 108 and the second bottom surface portion 115, and a connection portion is formed in a region sandwiched between the first connection surface portion 111 and the second connection surface portion 118. 123 is configured, and the thick portion 122 is configured by a portion other than the thin portion 121 and the connection portion 123.
Further, a depth dimension D1 of the first bottom surface portion 108 from the first main surface 103 is smaller than a depth dimension D2 of the second bottom surface portion 115 from the second main surface 105. Thus, by making the depth dimension D1 and the depth dimension D2 different, the thin-walled portion 121 changes from a flat plate shape to a curved plate shape after chemical strengthening. Note that the width dimension W1 of the first recess 107 and the width dimension W2 of the second recess 114 may be made different so that the first recess 107 overlaps the second recess 114 in plan view, for example, FIG. As shown in (A) and (B), the thin-walled portion 121 changes from a flat plate shape to a curved plate shape after chemical strengthening.

Here, the arithmetic average roughness Ra of the first and second

bottom surface portions

108 and 115 constituting the thin portion 121 of the glass substrate 101 is equal to the first and second

bottom surface portions

8 and 15 of the cover member 1 described above. Similarly, 50 nm or less is preferable, 45 nm or less is more preferable, and 30 nm or less is more preferable. The haze value of the thin portion 121 is preferably 16% or less, more preferably 15% or less, and still more preferably 10% or less.

The first connection surface portion 111 of the first recess 107 of the glass substrate 101 has a curved surface shape that smoothly connects with the first bottom surface portion 108, similarly to the first connection surface portion 11 of the first recess 7 of the cover member 1. Is preferred. It is preferable that the radius of curvature of the first connection surface portion 111 increases from the central portion of the first recess 107 toward the peripheral portion. The radius of curvature of the first connecting surface portion 111 is preferably set to be equal to or greater than the depth dimension D1 of the first bottom surface portion. The radius of curvature of the first connection surface portion 111 is preferably 0.1 mm or more and 2 mm or less. The connection portion between the first connection surface portion 111 and the first main surface 103 is the same as the connection portion between the first connection surface portion 11 and the first main surface 3 of the cover member 1 (see FIG. 3), and is smooth. A continuous curved surface is preferred.

The material of the first mask member 201 and the second mask member 301 is made of, for example, a photosensitive organic material, particularly an etchant-resistant material such as a photosensitive resin material such as a resist, a resin, a metal film, or ceramics. In the case of a resist, the first and second

recess forming holes

207 and 314 are formed by performing predetermined exposure and development.

The etching process may be either wet etching or dry etching, but wet etching is preferable from the viewpoint of cost. Examples of the etchant include a solution containing hydrofluoric acid as a main component in the case of wet etching, and a fluorine-based gas in the case of dry etching. By performing the etching treatment, a glass substrate having a plurality of recesses can be easily obtained.

The etching process is preferably performed while relatively moving the glass substrate 101 and the etchant in a direction (XY direction) parallel to the first main surface 103 or the second main surface 105 of the glass substrate 101. . Such etching may be performed while the glass substrate 101 is swung in the XY directions, may be performed by causing the etchant to flow in the XY directions, or may be performed in combination. Basically, the etching process isotropically proceeds with respect to the glass substrate 101. Therefore, the etching proceeds also in the side surface direction with a radius equal to the depth to be etched just below the opening sides of the first and second

recess forming holes

207 and 314, and the first and second recesses of the glass substrate 101. The first and second

connection surface portions

111 and 118 of the 107 and 114 can be curved to smoothly connect to the first and second

bottom surface portions

108 and 115. Further, if etching is performed while relatively moving the glass substrate 101 and the etchant in a direction parallel to the first main surface 103 or the second main surface 105 (XY direction) of the glass substrate 101, the progress of the etching is performed. Along with this, there is a flow of winding from the opening sides of the first and second

recess forming holes

207 and 314 toward the first and

second recesses

107 and 114 of the glass substrate 101. And the flow velocity from a peripheral part to a side surface becomes quicker than the center part of the 1st, 2nd recessed part 107,114. Therefore, the etching rate from the periphery of the first and

second recesses

107 and 114 to the side surface side becomes relatively high, and the curvature radii of the first and second

connection surface portions

111 and 118 are set to be the first and second recesses. 107 and 114 can be enlarged from the center to the periphery. In addition, the radius of curvature of the first and second

connection surface portions

111 and 118 can be greater than or equal to the depth dimension of the first and second

bottom surface portions

108 and 115. Moreover, the curvature radius of the side surface of the 1st, 2nd

connection surface parts

111 and 118 can be adjusted to 0.1 mm or more and 2 mm or less by adjusting etching processing time and the relative moving speed of the glass substrate 101 and an etchant. Furthermore, etching is performed while relatively moving the glass substrate 101 and the etchant in the direction (XY direction) parallel to the first main surface 103 or the second main surface 105 of the glass substrate 101 as described above. Thus, the first bottom surface 108 can be projected to the first main surface 103 side or the second main surface 105 side toward the center without performing chemical strengthening.

Further, in order to reduce the arithmetic average roughness Ra of the first and second

bottom surface portions

108 and 115 constituting the thin wall portion 121 to 50 nm or less, an etching process is performed so as to increase the fluidity of the etching solution on the glass substrate 101. Just do it. Further, in order to set the haze value of the thin portion 121 to 16% or less, an etching process may be performed so as to increase the fluidity of the etching solution on the glass substrate 101. In order to form the first main surface 103 side or the second main surface 105 side so that the bottom surface of the first concave portion 107 moves toward the center without performing chemical strengthening, an etching solution is used. The etching process may be performed so as to create a flow that hits the corners of one recess 107.

In order to make the depth dimensions D1 and D2 of the first and second

bottom surface portions

108 and 115 different, the length of the etching process, the concentration and flow of the chemical used for the etching process, the chemical temperature of the etching May be different.

The method of providing the first and

second recesses

107 and 114 on the first main surface 103 and the second main surface 105 of the glass substrate 101 is not limited to the method using the etching process as described above, but a method using machining. It doesn't matter. In the method by machining, a grindstone is brought into contact with the first main surface 103 and the second main surface 105 of the glass substrate 101 using a machining center or other numerically controlled machine tool, and a predetermined dimension is obtained. First and

second recesses

107 and 114 are formed. For example, grinding is performed at a spindle speed of 100 to 30,000 rpm and a cutting speed of 1 to 10,000 mm / min using a grindstone in which diamond abrasive grains, CBN abrasive grains or the like are fixed by electrodeposition or metal bond.

Subsequently, the bottom and side surfaces of the first and

second recesses

107 and 114 are polished to form the first and second

bottom surface portions

108 and 115 and the first and second

connection surface portions

111 and 118. Also good. In the polishing process, the polishing part of the rotary polishing tool is brought into contact with the bottom and side surfaces of the first and

second recesses

107 and 114 separately at a constant pressure and moved relatively at a constant speed. Do. By polishing under conditions of constant pressure and constant speed, the ground surface can be uniformly polished at a constant polishing rate. The pressure at the time of contact of the polishing portion of the rotary polishing tool is preferably 1 to 1,000,000 Pa in view of economy and ease of control. The speed is preferably 1 to 10,000 mm / min from the viewpoint of economy and ease of control. The amount of movement is appropriately determined according to the shape and size of the glass substrate 101. The rotary polishing tool is not particularly limited as long as the polishing portion can be polished, and examples thereof include a method of attaching the polishing tool to a spindle and a router having a tool chucking portion. As a material of the rotary polishing tool, at least the polishing portion can process and remove a workpiece such as cerium pad, rubber grindstone, felt buff, polyurethane, etc., and Young's modulus is preferably 7 GPa or less, more preferably 5 GPa or less, and the type is It is not limited. By using a member having a Young's modulus of 7 GPa or less as the material of the rotary polishing tool, the polishing portion is deformed by pressure to conform to the shapes of the first and

second recesses

107 and 114, and the bottom surface and the side surface are set as described above. Can be processed to a surface roughness of. Examples of the shape of the polishing portion of the rotary polishing tool include a circular or donut-shaped flat plate, a cylindrical shape, a shell type, a disk type, and a barrel type.

When polishing is performed by bringing the polishing processing portion of the rotary polishing tool into contact with the bottom and side surfaces of the first and

second recesses

107 and 114, it is preferable to perform the processing in a state where polishing abrasive slurry is interposed. In this case, examples of the abrasive grains include silica, ceria, alundum, white alundum (WA), emery, zirconia, SiC, diamond, titania, germania, and the like, and the particle size is preferably 10 nm to 10 μm. As described above, the relative moving speed of the rotary polishing tool can be selected in the range of 1 to 10,000 mm / min. The rotational speed of the polishing portion of the rotary polishing tool is 100 to 10,000 rpm. If the number of revolutions is small, the processing rate will be slow, and it may take too much time to achieve the desired surface roughness. If the number of revolutions is large, the processing rate will increase and the wear of the tool will become violent. May be difficult.

As described above, when the bottom and side surfaces of the first and

second recesses

107 and 114 are polished by bringing the rotary polishing tool into contact with each other with independent pressure, a pneumatic piston, a load cell, or the like can be used to adjust the pressure. For example, a pneumatic piston that moves the rotary polishing tool back and forth toward the bottom surfaces of the first and

second recesses

107 and 114, and other devices that move the rotary polishing tool back and forth toward the side surfaces of the first and

second recesses

107 and 114. If the pneumatic piston is provided, the pressure of the polishing portion with respect to the bottom and side surfaces of the first and

second recesses

107 and 114 can be adjusted. In this way, the pressures on the bottom and side surfaces of the first and

second recesses

107 and 114 are made independent, and a single rotary polishing tool is brought into contact with each surface at a constant pressure, with a constant speed. , Each surface can be uniformly polished at an independent polishing rate at the same time.

Note that polishing may be performed by relatively moving the rotary polishing tool and the glass substrate 101 along the shapes of the first and

second recesses

107 and 114. Any moving system may be used as long as the moving amount, direction, and speed can be controlled to be constant. For example, a method using a multi-axis robot or the like can be used.

As described above, in the glass substrate 101 on which at least the first and second

concave portions

107 and 114 facing in the Z direction are formed, the thin portion 121 is formed from a flat plate shape to a curved plate shape by subsequent chemical strengthening. .

Chemical strengthening refers to substitution (ion exchange) of alkali ions (for example, sodium ions) having a small ionic radius on the surface layer of glass with alkali ions (for example, potassium ions) having a large ionic radius. The method of chemical strengthening is not particularly limited as long as the alkali ions on the surface layer of the glass can be ion-exchanged with alkali ions having a larger ionic radius. For example, a glass containing sodium ions is replaced with a molten salt containing potassium ions. It can be implemented by processing. In general, the glass substrate is immersed in molten potassium nitrate at a temperature not higher than the glass transition point, and ion exchange is performed. As the potassium nitrate molten salt, a mixed molten salt in which potassium carbonate salt or the like is mixed may be used. In addition to the immersion, a spraying method of the molten salt or a coating method of powder or paste containing the molten salt may be used. Since such an ion exchange treatment is performed, the composition of the compressive stress layer on the glass surface layer is slightly different from the composition before the ion exchange treatment, but the composition at the center of the substrate thickness is almost the same as the composition before the ion exchange treatment. As a result, the potassium ion concentration in the 1st main surface 3 and the 2nd main surface 5 becomes higher than the potassium ion concentration in the thickness direction center of the cover member 1. FIG.

In the chemically strengthened glass, a compressive stress layer is formed on the surface layer. The surface compressive stress (CS) of the compressive stress layer of the thin portion 21 or the thick portion 22 of the cover member 1 is controlled within the above range. CS can be measured using a surface stress meter (for example, FSM-6000 manufactured by Orihara Seisakusho).

When ion exchange is performed between sodium ions on the glass surface layer and potassium ions in the molten salt by chemical strengthening, the depth (DOL) of the surface compressive stress layer generated by chemical strengthening can be measured by any method. For example, EPMA (electron probe) The alkali diffusion concentration analysis (potassium ion concentration analysis in this example) in the depth direction of the glass may be performed with a micro analyzer (electron beam microanalyzer), and the ion diffusion depth obtained by the measurement may be DOL. The DOL can also be measured using a surface stress meter (for example, FSM-6000 manufactured by Orihara Seisakusho). When ion exchange is performed between lithium ions on the glass surface layer and sodium ions in the molten salt, a sodium ion concentration analysis in the depth direction of the glass is performed with EPMA, and the ion diffusion depth obtained by the measurement is regarded as DOL. . The DOL of the thin portion 21 or the thick portion 22 of the cover member 1 is controlled within the above range.

The internal tensile stress (CT) of the cover member 1 (glass substrate 101) is preferably 300 MPa or less, more preferably 250 MPa or less, further preferably 200 MPa or less, and particularly preferably 170 MPa or less.

The strain point of the glass substrate 101 or the cover member 1 before chemical strengthening is preferably 500 ° C. or higher. This is because when the strain point of the glass substrate 101 or the cover member 1 before chemical strengthening is 500 ° C. or more, the surface compressive stress is hardly relaxed. 530 ° C. or higher is more preferable, and 550 ° C. or higher is more preferable.

Here, chemical strengthening may be performed only after the recess forming step, but is preferably performed before and after the recess forming step. That is, the manufacturing method of the cover member 1 includes a step of chemically strengthening the glass substrate 101 (first chemical strengthening step), a recess forming step of providing the first and

second recesses

107 and 114 in the glass substrate 101, a first And a step of chemically strengthening the glass substrate 101 provided with the

second recesses

107 and 114 again (second chemical strengthening step). According to this, first, in the first chemical strengthening step, CS and DOL equivalent to a normal flat cover member are given to the entire glass substrate 101 in which the first and

second recesses

107 and 114 are not provided. . Next, in the recess forming step, the thin portion 121 that is not strengthened is exposed by providing the first and

second recesses

107 and 114. Furthermore, in the second chemical strengthening step, the thin-walled portion 121 is not broken again, and the flat thin-walled portion 121 is formed into a curved plate shape like the thin-walled portion 21 as shown in FIG. Re-strengthen under appropriate strengthening conditions. Therefore, suitable strength can be given to the thin portion 121 while giving the thick portion 122 sufficient strength.

Thus, when chemical strengthening is performed before and after the recess forming step, the glass substrate 101 is heated to 400 to 500 ° C. in 30 to 100% KNO ₃ molten salt in the first chemical strengthening step in 1 to 24 hours. In the second chemical strengthening step, the glass substrate 101 is preferably brought into contact with 70 to 100% KNO ₃ molten salt heated to 350 to 450 ° C. for 1 minute to 3 hours. According to the conditions, the outermost surface CS of the thick portion 122 is 400 to 1300 MPa, the DOL is 15 to 100 μm, the CS and DOL at the inflection point are 10 to 1000 MPa, and 1 to 24 μm, respectively. 300 to 1300 MPa, DOL can be 5 to 25 μm.

Here, how to obtain “CS and DOL at the inflection point” will be described. FIG. 8 shows the CS-DOL profile under two different chemical strengthening conditions. In glasses subjected to chemical strengthening under

different conditions

1 and 2, curves representing the relationship between CS and DOL are curves a ₁ and a ₂ , respectively. The shapes of the curves a ₁ and a ₂ are different from each other. Moreover, CS and DOL of the curve a ₁ are represented by CS ₁ and DOL ₁ , and CS and DOL of the curve a ₂ are represented by CS ₂ and DOL ₂ , and the values of both are different. As described above, when the two-step chemical strengthening is performed on the glass substrate 101, a case where the glass substrate 101 chemically strengthened under the condition 1 is subsequently chemically strengthened under the condition 2 is considered. In this case, as shown in FIG. 9, the curve A representing the relationship between CS and DOL of the thick portion 122 of the glass substrate 101 is a curve in which the curves a ₁ and a ₂ are superimposed. As shown in FIG. 10, CS and DOL of the curve A are represented by CS _A and DOL _A. When such a thick portion 122 of the glass substrate 101 is measured by a surface stress meter, an inflection point P is observed between the outermost surface (position 0 on the X axis) and DOL _A. Since the inflection point P changes its shape under two-stage chemical strengthening conditions, it may be difficult to determine where the inflection point P is. Therefore, the intersection point Q is obtained as an alternative to the inflection point P, and the value of the intersection point Q is regarded as the above-described “CS and DOL at the inflection point”. The intersection point Q is an intersection point between the tangent line k ₁ at (0, CS _A ) on the curve A and the tangent line at (DOL _A , 0) with k ₂ . Then, CS _Q and DOL _Q which are the values of the Y coordinate and the X coordinate of the intersection point _Q are regarded as “CS and DOL at the inflection point”.

When the thin portion 121 is formed into a curved plate shape by the above-described machining, at least one of the first bottom surface portion 108 and the second bottom surface portion 115 of the thin portion 121 is subjected to chemical strengthening of the thin portion 121. In order to control to a desired curved surface shape, a film may be formed. Although not shown, such films include a surface film formed on the first bottom surface portion 108, a back surface film formed on the second bottom surface portion 115, and the first and second connection surface portions 111. , 118 and the like.

These films suppress chemical strengthening of the part where the film is formed. In order to exhibit the chemical strengthening suppressing effect, the film preferably contains an oxide, nitride, carbide, boride, silicide, metal or the like. This is because a film containing such a substance has a smaller diffusion coefficient of sodium ions and potassium ions in the film than in glass.

Examples of the oxide include a non-alkali oxide, a complex oxide containing an alkali element or an alkaline earth element, and SiO ₂ is particularly preferable. By applying SiO ₂ as the main component, diffusion of sodium ions and potassium ions in the film is moderately suppressed. Further, since the transmittance of the film is high and the refractive index is close to that of glass, the appearance change due to the coating can be minimized. Also, film composed mainly of SiO _2, the physical durability and chemical durability is high.

The film thickness is preferably 10 nm or more, more preferably 12 nm or more, further preferably 15 nm or more, particularly preferably 20 nm or more, and most preferably 25 nm or more. When the film thickness is 10 nm or more, chemical strengthening of the portion where the film is formed can be suppressed due to the effect of inhibiting ion exchange. As the film thickness increases, the chemical strengthening suppression effect increases and the curved surface shape can be controlled.

The film thickness is preferably 1000 nm or less, more preferably 500 nm or less, further preferably 200 nm or less, particularly preferably 100 nm or less, and most preferably 50 nm or less. If the film thickness exceeds 1000 nm, the thin portion 121 may not be easily strengthened. Moreover, there is a possibility that the difference in appearance between the site with and without the film becomes large.

Note that the cover member 1 may be glass that has not been subjected to chemical strengthening when the thin-walled portion 121 is formed into a curved plate shape by machining. That is, the glass substrate 101 does not necessarily need to be subjected to chemical strengthening treatment.

Also, as described above, the first main surface 103 and the second main surface 105 of the glass substrate 101 may be provided with a plurality of first and second

concave portions

107 and 114 that face each other. For example, as shown in FIG. 11, when the number of various devices such as the sensor 40H and the camera module 42H to be arranged on the back of the cover member 1 is plural, the same number of first and first devices as the number of the sensors 40H, the camera module 42H, etc. The second recesses 107 and 114 may be provided. The first main surface 103 and the second main surface 105 of the glass substrate 101 may be formed with recesses that do not face each other in addition to the first and

second recesses

107 and 114 that face each other.

FIG. 11 shows a state where the sensor 40H, the camera module 42H, and the liquid crystal layer (display panel) 44H are housed in a housing 43H such as a smartphone. Here, the cover member 1 is provided with a first recess 7H and a second recess 14H. The first recess 7H includes a first bottom surface portion 8H protruding in a curved shape on the first main surface 3 side and a first connection surface portion 11H, and the second recess 14H is a first bottom surface portion. In the region sandwiched between 8H, a second bottom surface portion 15H constituting a curved plate-like thin portion 21H and a second connection surface portion 18H are provided.
The sensor 40H is fixed to the second bottom surface portion 15H on the right side in FIG. The liquid crystal layer 44H is fixed to the second main surface 5 of the cover member 1 via the adhesive layer 45H. The camera module 42H has a lens-side tip fixed to the housing 43H. In such a configuration, the tip of the camera module 42H may extend outward from the housing 43H. However, as shown in the example in the figure, by providing the second recess 14H on the second main surface 5 of the cover member 1 at a position facing the camera module 42H, the base of the camera module 42H is provided in the second recess 14H. And the thickness of the camera module 42H can be absorbed. As a result, it is possible to contribute to the flash surface including the camera part of the device which is becoming thinner. Alternatively, the lens of the camera module 42H may be fixed to the second recess 14H of the cover member 1 with the tip and base of the camera module 42H reversed. Thereby, the thin portion 21H of the cover member 1 functions like a “lens protector” often used in lenses of single-lens reflex cameras, and has an effect of protecting the camera lens and preventing dust from entering. In this case, the bottom surface of the second recess 14H (the second bottom surface portion 15H of the thin portion 21H) needs to be optically polished, and the second connection surface portion 18H of the second recess 14H needs to be shielded from light. is there. An anti-reflection film such as an AFP film or MgF ₂ that makes it difficult to attach a fingerprint may be formed on the second concave portion 14H or the second bottom surface portion 15H of the thin portion 21H.

The shape of the first and

second recesses

7H and 14H is not particularly limited, and any shape may be applied. For example, the cross-sectional shape seen from the Z direction of the first and

second recesses

7H and 14H is not limited to an oval shape, and for example, a circular shape, an elliptical shape, a triangular shape, a rectangular shape, or the like can be applied.

The first main surface 3 or the second main surface 5 of the cover member 1 may be formed with an anti-glare treatment layer by anti-glare, and in addition, an antireflection layer, an antifouling layer, A functional layer such as an antifogging layer may be formed. The functional layer is preferably formed on the first main surface 3 of the cover member 1.
Examples of the antiglare treatment include a treatment by etching with hydrofluoric acid, a treatment by coating, and the like. In the case of the etching treatment, chemical strengthening may be performed after the etching, or etching may be performed after the chemical strengthening, but the etching is preferably performed before the chemical strengthening. In the case of a coating treatment, chemical strengthening may be performed after coating, or coating may be performed after chemical strengthening. In the case of the antiglare treatment layer by the coating treatment, the composition of the central portion of the thick portion and the composition of the antiglare treatment layer can be made different from each other in the thickness direction sectional view of the cover member 1. Accordingly, the composition can be changed so that the refractive index of the antiglare layer is lower than that of the cover member 1, and an antireflection effect can be obtained. When the component of the antiglare treatment layer is an inorganic material, either an etching treatment or a coating treatment may be performed, and when the component of the antiglare treatment layer is an organic material, a coating treatment may be performed. Note that an anti-fingerprint (AFP) layer may be formed on the antiglare layer. Further, for example, an inorganic fluoride or an inorganic chloride may be formed so that a layer having fluorine or chlorine exists on the outermost surface of the cover member or the antiglare treatment layer. As a result, the hydrophilicity is improved, so that the dirt can be easily washed with water.

When the anti-glare treatment region 50 is applied to the inside and the peripheral portion of the first recess 7 as shown in FIGS. 12A to 12C, the position of the sensor is instantly determined by tactile sensation without being visually recognized by the user. It is possible to obtain an effect of securing the finger sliding time and improving the authentication probability by friction due to the unevenness of the anti-glare treatment. Further, the antiglare treatment region 50 is preferably provided on at least a part of the peripheral edge of the first recess 7 of the cover member 1 as shown in FIGS. 13 (A) to (C). A sensor is disposed in the second recess 14 to detect a fingerprint of a finger touching the first recess 7. The detection sensitivity can be maintained by providing the antiglare treatment region 50 at the peripheral edge of the first recess 7.

Note that an anti-fingerprint coat layer 52 may be formed on the anti-glare treatment layer, for example, as shown in FIGS. 14 (A) to (D) and FIGS. 15 (A) to (D). The fingerprint-proof coating layer 52 may be formed on the entire first main surface 3 of the cover member 1. Thereby, even if the cover member 1 is touched with a finger, a fingerprint is difficult to be attached, and even if it is dirty, it is easy to wipe it off. Further, the fingerprint-proof coating layer 52 may be formed on the first bottom surface portion 8 of the thin-walled portion 21 that is frequently touched with a finger such as when performing fingerprint authentication. When the material of the anti-fingerprint coat layer 52 is likely to generate static electricity, the static electricity may reduce detection sensitivity depending on the type of sensor. In this case, as shown in FIGS. 14 (C), (D), and FIGS. 15 (A) to (D), the thick portions 22 (see FIG. 3) of the cover member 1 other than the first concave portions 7 are used. It may be applied only to one main surface 3. Note that the functional layer formation described above may be formed in advance on the glass substrate 101 (see FIG. 7A).
Note that the cover member 1 shown in FIGS. 12 to 15 and FIG. 16 described later has the same configuration as that shown in FIG. 2, but some of the reference numerals indicating the respective components in the figure are omitted. It is.

Further, the first main surface 3 and the second main surface 5 of the cover member 1 are preferably polished. A tempered glass sheet subjected to chemical strengthening by ion exchange has defects on its outermost surface. In addition, fine irregularities of up to about 1 μm may remain. When a force acts on the cover member 1, the stress concentrates on a location where the above-described defect or fine unevenness exists, and the cover member 1 may be broken even with a force smaller than the theoretical strength. For this reason, the layer (defect layer) having defects and fine irregularities existing on the first main surface 3 and the second main surface 5 of the cover member 1 after chemical strengthening is removed by polishing. The thickness of the defect layer in which defects are present is usually 0.01 to 0.5 μm although it depends on the conditions of chemical strengthening. This polishing is performed by, for example, a double-side polishing apparatus. The double-side polishing apparatus has a carrier mounting portion having a ring gear and a sun gear that are driven to rotate at a predetermined rotation ratio, and a metal upper surface plate and a lower surface plate that are driven to rotate reversely with respect to the carrier mounting portion. The carrier mounting portion is mounted with a plurality of carriers that mesh with the ring gear and the sun gear. The carrier rotates on its own center as an axis and moves in a planetary gear so as to revolve around the sun gear, and both sides of the plurality of cover members 1 (the first main surface 3 and the first main surface 3 and the first main surface 3) mounted on the carrier by the planetary gear movement. 2 main surface 5) is polished by friction with the upper surface plate and the lower surface plate.

Furthermore, a printing layer may be provided on the second main surface 5 of the cover member 1. The print layer can be formed from, for example, an ink composition containing a predetermined color material. In addition to the color material, the ink composition contains a binder, a dispersant, a solvent, and the like as necessary. The color material may be any color material (colorant) such as a pigment or a dye, and can be used alone or in combination of two or more. The color material can be appropriately selected depending on the desired color. For example, when a light shielding property is required, a black color material or the like is preferably used. The binder is not particularly limited, and for example, polyurethane resin, phenol resin, epoxy resin, urea melamine resin, silicone resin, phenoxy resin, methacrylic resin, acrylic resin, polyarylate resin, polyester type Resin, polyolefin resin, polystyrene resin, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polycarbonate, celluloses, polyacetal, and other known resins (thermoplastic resin, thermosetting resin) Resin, photocurable resin, etc.). A binder can be used individually or in combination of 2 or more types.

The printing method for forming the printing layer is not particularly limited, and gravure printing method, flexographic printing method, offset printing method, relief printing method, screen printing method, pad printing method, spray printing method, inkjet printing method, etc. The appropriate printing method can be applied.

By adding a color to the place corresponding to the second thin part constituting part 16 or the second connecting part constituting part 17 (see FIG. 2A) in the second bottom face part 15, it is easy to visually understand the place. it can. Further, when the place corresponding to the second connecting portion constituting portion 17 is made by specular reflection printing (for example, silver printing), the shape having the curvature of the second connecting portion constituting portion 17 shows the lens effect, and the second connection Even if the reflection corresponding to the part component 17 is reflected at a wide angle even if the angle of the cover member 1 is changed, it can be sparkled and a high-class feeling can be produced.

It is preferable that the printing is performed separately for the second recess 14 and the flat portion where the second recess 14 is not formed on the second main surface 5 of the cover member 1. This is because the shape followability is not so high in the printing direction such as the screen printing method, and it is difficult to print the second recess 14 and the flat portion where the second recess 14 is not formed at a time. Therefore, a highly accurate printing layer can be formed by printing these parts individually. Further, the color or texture of printing can be changed between the second concave portion 14 and the flat portion where the second concave portion 14 is not formed, so that the position of the sensor 40 can be visually displayed in an easy-to-understand manner, which is an accent on the design.

More specifically, as shown in FIG. 16A, a first printing layer 31 is provided by a screen printing method or the like on a flat portion where the second recess 14 is not formed on the second main surface 5. In the screen printing, after a printing material is placed on a screen having an opening, a squeegee is pressed and slid on the screen, and the printing material is pushed out from the opening of the screen to print a pattern of the opening. Say the method. Moreover, since the 2nd recessed part 14 has the 2nd bottom face part 15 which is a curved surface shape, the pad printing method is suitable with respect to the 2nd recessed part 14. FIG. Thereby, the second printed layer 32 is formed on the entire second bottom surface portion 15 of the second recess 14. Here, the pad printing method is a method in which a soft pad (for example, a silicone pad) provided with an ink pattern on its surface is pressed against a target substrate to transfer the ink pattern onto the substrate surface for printing. Pad printing is sometimes called tampo printing. As described above, in the pad printing method, a pad that is relatively soft and has good shape followability is used. Therefore, printing on the second bottom surface portion 15 is preferably performed by the pad printing method. On the other hand, the printing method such as the screen printing method is not suitable because the shape following property is not so high and the ink cannot be printed on the second bottom surface portion 15. The order of printing on the first and second print layers 31 and 32 is not particularly limited.

Further, as shown in FIG. 16B, a flat portion where the second concave portion 14 is not formed in the second main surface 5, the second thin portion constituting portion 16 of the second bottom surface portion 15, and the second You may print separately with the connection part component part 17 of this. In this case, the 1st printing layer 31 is provided in the flat part in which the 2nd recessed part 14 is not formed in the 2nd main surface 5 by a screen printing method etc. Next, the second thin portion constituting portion 16 and the second connecting portion constituting portion 17 of the second recess 14 are respectively provided with second and third print layers 32 and 33 by a pad printing method. The order of printing for the first to third printing layers 31 to 33 is not particularly limited. Further, by changing the color or texture of printing between the first print layer 31, the second print layer 32, and the third print layer 33, the position of the sensor 40 can be easily visually recognized, and the design accents and Become. For example, when the first print layer 31 and the second print layer 32 are the same color and the third print layer 33 is printed in a different color, the design is such that the third print layer 33 is recognized as an annular pattern. it can.

In addition, the printing method for the flat portion such as the portion where the second concave portion 14 is not formed on the second main surface 5 is not limited to the screen printing method, and the film thickness of the printing layer can be accurately controlled. For example, a rotary screen printing method, a relief printing method, an offset printing method, a spray printing method, or the like may be used. Also, printing by electrostatic copying method, thermal transfer method, ink jet method or the like may be used.
Further, the printing method for the curved surface shape such as the second concave portion 14 is not limited to the pad printing method as long as the followability to the curved surface shape is good, and for example, a spray printing method may be adopted.

The above-described cover member 1 includes at least a plurality of first and

second recesses

107 and 114 from a glass substrate 101 provided with a plurality of first and

second recesses

107 and 114 as shown in FIG. It can also be obtained by separating them so as to include one.
In FIG. 17, the outer shape of the cover member 1 to be separated is indicated by a broken line, and a plurality of cover members 1 can be obtained by cutting the glass substrate 101 along the broken line. The cutting line is a straight line as shown by a broken line in the figure, but it need not be a straight line and may be a curved line.

The first main surface 103 and the second main surface 105 of the glass substrate 101 are provided with a plurality of first and second

concave portions

107 and 114 that face each other. As will be described later, the plurality of first and

second recesses

107 and 114 are provided by etching the first main surface 103 and the second main surface 105. As will be described later, the plurality of first and

second recesses

107 and 114 are also provided by grinding processing, heat deformation, or the like.

The glass substrate 101 is provided with a plurality of thin portions 121 formed in a flat plate shape by providing a plurality of first and second

concave portions

107 and 114, and a connection portion (not shown) (see FIG. 7C). A thick portion 122 connected to the plurality of thin portions 121. The first and

second recesses

107 and 114 are provided at predetermined intervals in the X direction and the Y direction. Therefore, the thin portion 121 is also provided at predetermined intervals in the X direction and the Y direction. The plurality of first and

second recesses

107 and 114 are not necessarily provided at predetermined intervals. They may be arranged at a plurality of types of intervals, or at least some of them may be arranged at random intervals. However, in order to improve the space efficiency when separating the plurality of cover members 1, a plurality of first and

second recesses

107 and 114 are provided at predetermined intervals as shown in FIG. It is preferable to spread 1 without gaps.

Here, the arithmetic average roughness Ra of the outermost surface of the thin wall portion 121 is preferably 50 nm or less, more preferably 45 nm or less, and further preferably 30 nm or less. The haze value of the thin portion 121 is preferably 16% or less, more preferably 15% or less, and still more preferably 10% or less.

As shown in FIG. 7C, the first and second

connection surface portions

111 and 118 of the first and second

concave portions

107 and 114 of the glass substrate 101 are connected to the first and second

bottom surface portions

108 and 115, respectively. A curved shape that connects smoothly is preferable. It is preferable that the curvature radii of the first and second

connection surface portions

111 and 118 increase from the central portion of the first and second

concave portions

107 and 114 toward the peripheral portion. The radii of curvature of the first and second

connection surface portions

111 and 118 are preferably set to be greater than or equal to the depth dimensions of the first and second

bottom surface portions

108 and 115. The curvature radii of the first and second

connection surface portions

111 and 118 are preferably 0.1 mm or more and 2 mm or less. The connecting portion between the first and second connecting

surface portions

111 and 118 and the first and second

main surfaces

103 and 105 is preferably a smoothly continuous curved surface.

As shown in FIGS. 18A and 18B, at least one of the first main surface 103 and the second main surface 105 of the glass substrate 101 is aligned when the plurality of cover members 1 are separated. A plurality of first marks 131 and second marks 132 for performing are provided. 18A and 18B, the extension line in the X direction of the outer shape (broken line in FIG. 17) of each cover member 1 is represented by A, and the extension line in the Y direction is represented by B. The first marks 131 are arranged in pairs near the cover member 1 so as to sandwich the X-direction extension line A, and paired so as to sandwich the Y-direction extension line B. Each first mark 131 includes a pair of first mark pieces 131A. The first mark piece 131A has a substantially L shape composed of two vertical sides. One side of the first mark pieces 131A adjacent to each other faces each other with a slight gap. The second marks 132 are arranged at the four corners of the glass substrate 101, respectively. The second mark 132 has a substantially cross shape composed of two vertical sides. Of the two sides constituting the second mark 132, a part of the side parallel to the X-direction extension line A intersects with the Y-direction extension line B, and a side parallel to the Y-direction extension line B is a part thereof. Intersects with the X-direction extension line A.

When the cover member 1 is cut and separated from the glass substrate 101, the position of the second mark 132 is read, the cutting location is selected, and the intermediate portion of the first mark 131 (X-direction extension line A or Y-direction extension line). It can be confirmed that the cutting line has come to B), and whether it is cut correctly.

Next, a method for manufacturing the glass substrate 101 will be described. First, the raw materials of each component are prepared so as to have the composition described later, and heated and melted in a glass melting furnace. The glass is homogenized by bubbling, stirring, adding a clarifying agent, etc., formed into a glass plate having a predetermined thickness by a known forming method, and slowly cooled. A glass member formed into a flat plate shape by an arbitrary forming method is gradually cooled and then cut into a desired size. In addition, when more exact dimensional accuracy is required, the glass member after cutting may be chamfered or polished. Thereby, the glass substrate 101 which has the flat 1st main surface 103 and the 2nd main surface 105, and is flat form as a whole is obtained.

Next, a chemical strengthening process is performed on the glass substrate 101 (first chemical strengthening step). In the first chemical strengthening step, the glass substrate 101 is preferably brought into contact with 30 to 100% KNO ₃ molten salt heated to 400 to 500 ° C. for 1 to 24 hours. Thereby, CS and DOL equivalent to a normal flat cover member are given to the whole glass substrate 101 (thin wall portion 121 and thick wall portion 122). The CS of the glass substrate 101 (thick portion 122) obtained by the first chemical strengthening step is preferably 400 MPa or more, more preferably 500 MPa or more, and further preferably 600 MPa or more. Similarly, the DOL is preferably 15 μm or more, more preferably 20 μm or more, and further preferably 25 μm or more.

Subsequently, the process proceeds to a recess forming step for providing the first and

second recesses

107 and 114 on the first main surface 103 and the second main surface 105 of the glass substrate 101. In the example described below, a plurality of first and

second recesses

107 and 114 are provided on the first and second

main surfaces

103 and 105 of the glass substrate 101 as shown in FIG. In the recess forming step, first and

second mask members

201A and 301A as shown in FIG. 19B are arranged on the first and second

main surfaces

103 and 105 of the glass substrate 101, and then the glass substrate 101 is placed. Etching is performed on the substrate.

The X and Y direction dimensions of the first and

second mask members

201A and 301A are set so as to cover the entire first and second

main surfaces

103 and 105 of the glass substrate 101. In the example of FIG. 19B, the X-direction dimension and the Y-direction dimension of the

first mask members

201A, 301A are substantially equal to the X-direction dimension and the Y-direction dimension of the glass substrate 101. Further, the

first mask members

201A and 301A have first and second recess formation holes 207A and 314A for forming a plurality of first and

second recesses

107 and 114 in the glass substrate 101, respectively. A plurality are provided at predetermined intervals in the direction and the Y direction. Accordingly, the etchant reaches the first and second

main surfaces

103 and 105 of the glass substrate 101 via the plurality of first and second recess forming holes 207A and 314A, and the plurality of first and second recesses are formed. 107 and 114 are formed.

As described above, the first mark 131 and the second mark 132 are attached to the glass substrate 101 formed with the plurality of first and

second recesses

107 and 114 by a method such as laser engraving or printing. A glass substrate 101 as shown in FIG. 17 is obtained. Then, the position of the second mark 132 is read, the cutting position is specified, and the glass substrate 101 is cut with a cutting tool such as a diamond cutter, whereby the plurality of cover members 1 are separated. After that, it is confirmed that the cover member 1 is separated into a desired shape when the cutting line passes through the intermediate portion (X-direction extension line A or Y-direction extension line B) of the pair of first marks 131. Is done.

As shown in FIG. 20A, the first and

second mask members

201B and 301B have first and second

groove forming holes

220B and 320B corresponding to the outer shapes of the plurality of cover members 1. May be. For example, when etching is performed using such a first mask member 201B, the outer shape of the plurality of cover members 1 is formed on the first main surface 103 of the glass substrate 101 as shown in FIG. Corresponding grooves 140 are provided. The plurality of cover members 1 can be separated by cutting the glass substrate 101 along the groove 140. Thus, by providing the groove part 140 corresponding to the external shape of the cover member 1 in the glass substrate 101 in advance, the cover member 1 can be more accurately separated. Further, it is not necessary to prepare a mask having the outer shape of the cover member as in the prior art.

Further, as shown in FIG. 21, a plurality of cover members 1 may be separated from the glass substrate 101 so as to include a plurality of first and

second recesses

107 and 114, respectively. For example, as shown in FIG. 11, when the number of various devices such as the sensor 40 and the camera module 42H to be arranged on the back of the cover member 1 is plural, the same number of first and first devices as the number of the sensors 40, the camera module 42H, and the like. The second recesses 107 and 114 may be provided.

As described above, by separating the plurality of cover members 1 from the glass substrate 101 so as to include at least one of the first and

second recesses

107 and 114, a flat plate shape as shown in FIG. The cover member 1 having the thin portion 121 is obtained. The cover member 1 may be glass having one or more bent portions. Further, the first and

second recesses

107 and 114 may be formed in the bent portion.

Here, after chemically strengthening the glass substrate 101 on which the first and

second recesses

107 and 114 are formed again, the plurality of cover members 1 may be separated, and after separating the plurality of cover members 1, respectively. The cover member 1 may be chemically strengthened. That is, the former is in the order of the first chemical strengthening step, the recess forming step, the second chemical strengthening step, and the (surface polishing step) cover member separating step, whereas the latter is the first chemical strengthening step and the recess forming step. It is different in the order of the process, the cover member separation process, the second chemical strengthening process, and the (surface polishing process). In both cases, the surface polishing step is optional, but when this step is performed, it is performed after the final chemical strengthening step (the last chemical strengthening step, that is, the second chemical strengthening step). Moreover, it is preferable to chamfer the end face after the cover member separation step.

In either case of the former or the latter, after the first chemical strengthening step, the thick portion 22 is given the same strength as a normal flat cover member having no recess, By forming the

recesses

7 and 14, the flat thin portion 21 that is not strengthened is exposed, and the thin portion 21 is formed into a curved plate shape as shown in FIG. 2A by the second chemical strengthening step. At the same time, the thin-walled portion 21 is given necessary reinforcement as much as possible. In the second chemical strengthening step, the cover member 1 or the glass substrate 101 is preferably brought into contact with 70 to 100% KNO ₃ molten salt heated to 350 to 450 ° C. for 1 minute to 3 hours. The CS of the thin portion 21 obtained by the second chemical strengthening step is preferably 300 MPa or more, more preferably 400 MPa or more, and further preferably 500 MPa or more. Similarly, DOL is preferably 5 μm or more, more preferably 7 μm or more, and even more preferably 10 μm or more.

In the former case, the two chemical strengthening steps, the recess forming step, and the surface polishing step can all be performed in the state of the large glass substrate 101, so that the steps can be made efficient.

In the latter case, since the first chemical strengthening step and the recess forming step can be performed in the state of the large glass substrate 101, the steps can be made more efficient to some extent. In addition, since the second chemical strengthening step is performed after the cover member is separated and the thin portion 21 is formed into a curved plate shape, it is possible to cope with a small equipment such as a polishing apparatus or an ion exchange bath, and the cover member end surface can be chemically strengthened. It is easy to improve the end face strength.

In addition, in the manufacturing method of the cover member 1 mentioned above, although the 1st chemical strengthening process was implemented before the recessed part formation process, you may implement after a recessed part formation process. In this case, the second chemical strengthening step need not be performed. Specifically, the recess forming step, the first chemical strengthening step, the (surface polishing step), or the cover glass separating step are performed in this order, or the recess forming step, the cover glass separating step, the first chemical strengthening step, (the surface polishing step). ) In this order. The surface polishing step is optional, but when this step is performed, it is performed after the final chemical strengthening step (the last chemical strengthening step, that is, the first chemical strengthening step).

Also, the second chemical strengthening step does not need to strengthen the entire cover member 1. For example, at least a part of the cover member 1 may be chemically strengthened, for example, chemical strengthening is performed only on the end face, chemical strengthening is performed only on the bent portion, and chemical strengthening is performed only on the concave portion. Thereby, since a desired site | part can be chemically strengthened selectively, it can control to desired intensity | strength. Furthermore, the cover member 1 can be controlled to a desired shape by partially chemically strengthening the cover member 1.

(Glass composition)
Examples of the cover member 1 and the glass substrate 101 include any one of the following glasses (i) to (vii). The glass compositions (i) to (v) below are compositions expressed in terms of mol% based on oxides, and the glass compositions (vi) to (vii) are expressed in terms of mass% based on oxides. Composition.
(I) 50-80% of SiO ₂ , 2-25% of Al ₂ O ₃ , 0-10% of Li ₂ O, 0-18% of Na ₂ O, 0-10% of K ₂ O, MgO Glass containing 0-15%, CaO 0-5% and ZrO ₂ 0-5%.
(Ii) SiO ₂ and 50 to 74%, the _{_{Al 2 O 3 1 ~ 10%}} , a Na ₂ O 6 - 14% of _{K 2} O 3 - 11% of MgO 2 - 15% CaO 0 to 6% and 0 to 5% of ZrO ₂ , the total content of SiO ₂ and Al ₂ O ₃ is 75% or less, the total content of Na ₂ O and K ₂ O is 12 to 25%, MgO and Glass with a total CaO content of 7 to 15%.
(Iii) SiO ₂ 68 to 80%, the _{_{Al 2 O 3 4 ~ 10%}} , a Na ₂ O 5 ~ 15%, the _{K 2} O 0 ~ 1%, the MgO 4 ~ 15% and ZrO ₂ 0 Glass containing ˜1% and the total content of SiO ₂ and Al ₂ O ₃ is 80% or less.
(Iv) SiO ₂ 67-75%, Al ₂ O ₃ 0-4%, Na ₂ O 7-15%, K ₂ O 1-9%, MgO 6-14%, CaO 0-0 1% and 0 to 1.5% of ZrO ₂ , the total content of SiO ₂ and Al ₂ O ₃ is 71 to 75%, the total content of Na ₂ O and K ₂ O is 12 to 20% Glass.
(V) SiO ₂ 60-75%, Al ₂ O ₃ 0.5-8%, Na ₂ O 10-18%, K ₂ O 0-5%, MgO 6-15%, CaO Glass containing 0-8%.
(Vi) SiO ₂ 63-75%, Al ₂ O ₃ 3-12%, MgO 3-10%, CaO 0.5-10%, SrO 0-3%, BaO 0-3% Na ₂ O 10 to 18%, K ₂ O 0 to 8%, ZrO ₂ 0 to 3%, Fe ₂ O ₃ 0.005 to 0.25%, R ₂ O / Al ₂ O ₃ (wherein R ₂ O is Na ₂ O + K ₂ O) is 2.0 or more and 4.6 or less.
(Vii) a SiO ₂ 66 ~ 75%, the _{_{Al 2 O 3 0 ~ 3%}} , the MgO 1 ~ 9%, the CaO 1 ~ 12%, 10 ~ 16% of Na ₂ O, the _{K 2} O 0 ~ Glass containing 5%.

Example 1
An embodiment of the glass substrate 101 shown in FIG. 17 and the manufacturing method thereof will be described. A glass substrate 101 having an X-direction length of 730 mm, a Y-direction length of 920 mm, and a Z-direction thickness of 0.5 mm was used.

First, in the first chemical strengthening step, the glass substrate 101 was immersed in 60% KNO ₃ molten salt heated to 450 ° C. for 10.5 hours.

Next, in the recess forming step, a total of 65 first and

second recesses

107 and 114 were formed on the glass substrate 101 in the X direction in 5 rows at a pitch of 130 mm and in the Y direction in 13 columns at a pitch of 65 mm (see FIG. 19 (A)). The first and

second recesses

107 and 114 were in the shape of an ellipse having an X-direction length of 10 mm and a Y-direction length of 13 mm. The depth of the first recess 107 in the Z direction was 0.15 mm, and the depth of the second recess 114 in the Z direction was 0.2 mm. That is, the thickness in the Z direction of the flat thin portion 121 formed by providing the first and

second recesses

107 and 114 was 0.15 mm.

The method for forming the first and

second recesses

107 and 114 on the first and second

main surfaces

103 and 105 of the glass substrate 101 is as follows. First, a resist material is applied to the first and second

main surfaces

103 and 105 of the glass substrate 101, and the resist material is exposed to holes having the same size as the bottom surfaces of the first and second recesses 107 and 114 (first and second surfaces). The second recess forming holes 207A and 314A) were opened, and the first and

second mask members

201A and 301A shown in FIG. 19B were formed.

Next, in a state where the first and

second mask members

201A and 301A are disposed on the first and second

main surfaces

103 and 105, the glass substrate 101 is immersed in an etching solution containing hydrofluoric acid (HF), and the XYZ directions The glass substrate 101 was etched by allowing the HF solution to permeate through the front side and the second recess formation holes 207A and 314A. At this time, the flow of the etching solution in the second recess was more active than that in the first recess 107. After etching the glass substrate 101 until the depth of the first recess 107 becomes 0.15 mm and the depth of the second recess 114 becomes 0.2 mm, the glass substrate 101 is pulled up from the HF solution, and a resist material (first ,

Second mask members

201A, 301A) were peeled off, washed and dried. By the above operation, the glass substrate 101 having the first and second

concave portions

107 and 114 shown in FIG. 17 and the flat thin portion 121 as shown in FIG.

Then, in the second chemical strengthening step, the glass substrate 101 is brought into contact with 100% KNO ₃ molten salt heated to 400 ° C. for 7 minutes so that the flat thin portion 121 is shown in FIG. The first main surface 103 was formed into a curved surface protruding to the side.

In addition, a plurality of first and

second marks

131 and 132 for positioning when separating the plurality of cover members 1 were formed on the periphery of the glass substrate 101. As shown in FIG. 2A, a first connection surface portion 111 of the first recess 107 (referred to as “side surface of the first recess 107” in the first and second embodiments) and a second recess 114 are formed. The second connecting portion component 117 (referred to as “the side surface of the second recess 114” in the first and second embodiments) of the second bottom surface portion 115 is respectively the first bottom surface portion 108 (in the first and second embodiments). It was a curved shape that smoothly connected to the second thin-walled component 116 (referred to as the “bottom surface of the second recess 114” in Examples 1 and 2). . The radius of curvature from the bottom surface to the side surface of the first concave portion 107 was about 0.4 mm at the maximum, and the radius of curvature from the bottom surface to the side surface of the second concave portion 114 was about 0.4 mm at the maximum. Further, the connection portions between the side surfaces of the first and

second recesses

107 and 114 and the flat portions of the first and second

main surfaces

103 and 105 were substantially vertical.

As the glass substrate 101, Dragontrail (registered trademark of Asahi Glass Co., Ltd.), which is an aluminosilicate glass of Asahi Glass Co., Ltd., was used.

(Example 2)
Examples of the glass substrate 101 and its manufacturing method will be described. For Example 1, Dragontrail-X, which is an aluminosilicate glass manufactured by Asahi Glass Co., Ltd., was used as the glass substrate 101. In the first chemical strengthening step, the glass substrate 101 was brought into contact with 60% KNO ₃ molten salt heated to 450 ° C. for 15 hours. Further, the first and second

concave portions

107 and 114 were formed into a circular shape having a diameter of 10 mm, and the flat thin portion 121 was formed. Further, after the etching, the glass substrate 101 is taken out from the etching solution containing hydrofluoric acid (HF), and then held for 30 seconds, and then the resist material (first and

second mask members

201A and 301A) is peeled off and washed. . In the second chemical strengthening step, the glass substrate 101 is brought into contact with 100% KNO ₃ molten salt heated to 400 ° C. for 10 minutes, and the flat thin portion 121 is formed as shown in FIG. 1 was formed into a curved surface protruding toward the main surface 103 side. A glass substrate 101 was produced in the same manner as in Example 1 except for the above.

The side surfaces of the first and

second recesses

107 and 114 are curved surfaces that smoothly connect to the bottom surfaces of the first and

second recesses

107 and 114, and the radius of curvature from the bottom surface to the side surface of the first recess 107 is the second The radius of curvature from the bottom surface to the side surface of the recess 114 was about 0.4 mm at the maximum and about 0.4 mm at the maximum, respectively. The connecting portion between the side surfaces of the first and second

concave portions

107 and 114 and the flat portion of the first and second

main surfaces

103 and 105 is a smoothly continuous curved surface, and the radius of curvature of the connecting portion is About 0.4 mm. The radius of curvature from the bottom surface to the side surface of the first and second

concave portions

107 and 114 was a radius of curvature that is concave toward the glass substrate 101 side. The shape from the side surface of the first and second

concave portions

107 and 114 to the flat portion of the first and second

main surfaces

103 and 105 is an inflection point in the middle of the side surface of the first and second

concave portions

107 and 114. There was a shape.

(Example 3)
An embodiment of the cover member 1 and the manufacturing method thereof will be described. The glass substrate 101 of Example 1 or 2 was cut into a rectangular size of 130 mm × 65 mm having one each of the first and

second recesses

107 and 114 using a wheel cutting device for cutting glass. As a result, a plurality of rectangular cover members 1 each having one first and second

concave portions

107 and 114 were obtained. When cutting, the second mark 132 was read to determine the cutting position. In addition, whether or not it was cut correctly was confirmed by checking whether or not a cutting line runs in the center of the first mark 131 and confirmed that it was correctly cut into a predetermined shape. Since the positional relationship between the second mark 132 and the first and second

concave portions

107 and 114 is correlated, the first and second

concave portions

107 and 114 can be arranged at desired positions of 130 mm × 65 mm.

As shown in FIG. 22 (A), the corners 2 at the four corners of the rectangular cover member 1 in plan view were cut by CNC (grinding stone) to give a shape with a curvature R. At the same time, chamfering was performed by CNC. Chamfering can be done in various ways, such as R chamfering (processing to make the glass edge in a semicircular state) and C chamfering (processing to scrape obliquely), but in this example, it was C chamfering. In the CNC process, speaker holes 4 are provided at predetermined positions. The first and

second recesses

7 and 14 may be formed after the speaker hole 4 is provided in advance. Further, the speaker hole 4 may be provided by etching in another process. The speaker hole 4 may be provided by cutting out the end surface of the cover member 1.

In the cover member 1 (Dragonrail) obtained from the glass substrate 101 of Example 1, CS at the outermost surface of the thick part is 625 MPa, DOL is 45 μm, CS at the inflection point is 200 MPa, DOL is 6 μm, and the thin part is The outermost surface CS was 625 MPa, and the DOL was 6 μm. In the cover member 1 (Dragonrail-X) obtained from the glass substrate 101 of Example 2, CS of the outermost surface of the thick part is 800 MPa, DOL is 45 μm, CS at the inflection point is 250 MPa, DOL is 6 μm, thin wall The outermost surface CS of the part was 800 MPa, and the DOL was 6 μm. CS and DOL were measured using a glass surface stress meter FSM-6000 manufactured by Orihara Seisakusho. As described above, the values of the intersection point Q are CS and DOL of the inflection points (see FIGS. 8 to 10).

Next, printing was performed on the second main surface 5 of the cover member 1. This printing forms black three layers 31 to 33 and is substantially the same as the method of forming the first to third printing layers 31 to 33 shown in FIG.

First, as shown in FIG. 22B, on the second main surface 5 of the cover member 1, the speaker hole 4, the second recess 14, and a portion corresponding to the display portion of the portable information terminal (display area 6). ), Black printing was performed on the area except for the first printed layer 31. Next, as shown in FIG. 22C, black printing was performed on the second thin portion constituting portion 16 of the second recess 14 to form the second printed layer 32. Subsequently, as shown in FIG. 22D, black printing was performed on the second connection portion constituting portion 17 of the second recess 14 to form a third printed layer 33.

The first printing layer 31 was formed by screen printing, and printed in a Z-direction thickness of about 4 μm by one screen printing. This was carried out twice, and the thickness of the first printed layer 31 in the Z direction was about 8 μm. The second printed layer 32 was formed by pad printing. A Z-direction thickness of about 3 μm was printed by one pad printing. This was performed three times, and the thickness of the second printed layer 32 in the Z direction was about 9 μm. The third printed layer 33 was formed by pad printing. This pad printing was performed three times, and the thickness of the third printed layer 33 in the Z direction was about 9 μm. The third print layer 33 was configured to overlap the first and second print layers 31 and 32 in the XY direction (to face each other in the Z direction). As a result, black printing could be performed without light passing through the second recess 14. When viewed from the first main surface 3 of the cover member 1 (the surface opposite to the second main surface 5 on which the second recess 14 is formed), where the boundary of the second recess 14 is located depending on the color. I did n’t understand.

As a black printing method, the black printing of the first printing layer 31 is performed once, and the black printing of the first printing layer 31 is performed once after the printing of the third printing layer 33 is finished. There is also a method. Further, if the process conditions are optimized, the second thin portion constituting portion 16 and the second connecting portion constituting portion 17 of the second recess 14 are simultaneously black printed, and the second and third printed

layers

32, 33 are printed. Can be formed simultaneously.

Finally, a fingerprint-proof coating layer (Anti-Fingerprint) was formed on the first main surface 3 of the cover member 1. The method for forming the anti-fingerprint coating layer is generally a solution coating method, a spray method, and a vapor deposition method. Thus, a desired cover member 1 was produced.

Example 4
An embodiment of the portable information terminal will be described. The sensor surface of the fingerprint authentication sensor 40H (see FIG. 11) was brought into contact with and secured to the second bottom surface portion 15 of the second recess 14 of the cover member 1 of Example 3. The thickness of the adhesive layer 41 in the Z direction was about 10 μm. A liquid crystal layer 44H (display panel) was laminated on the non-printing portion of the second main surface 5 of the cover member 1 via an adhesive layer 45H. The thickness in the Z direction of the adhesive layer 45H was about 100 μm. A smartphone was produced by incorporating the cover member 1 into the housing 43H together with other components with the first main surface 3 facing outside.

Since the first concave portion 7H exists on the outer surface of the cover member at the position of the fingerprint authentication sensor 40H arranged on the display side of the smartphone, the position of the fingerprint authentication sensor 40H can be easily recognized by visual or tactile sense. Since the contact position of the finger is fixed to some extent by the one recess 7H, fingerprint reading is facilitated.

(Example 5)
When a portable information terminal is manufactured using the cover member 1 according to the third embodiment, the sensor surface of the fingerprint authentication sensor 40H is brought into contact with and fixed to the second bottom surface portion 15 of the thin portion 21 of the cover member 1. did. When the second concave portion 14 is provided on the second main surface 5 of the cover member 1 and the fingerprint authentication sensor 40H is disposed on the second bottom surface portion 15, there is no problem in the function of the fingerprint authentication sensor 40H. In this case, the size of the fingerprint authentication sensor 40H may be larger than that of the first recess 7. Since the size of the fingerprint authentication sensor 40 </ b> H is larger than that of the first recess 7, the strength of the cover member 1 in which the thin portion 21 is thin can be increased. More preferably, as shown in FIG. 5B, the dimension of the first recess 7 may be larger than the dimension of the sensor body 46D and smaller than the dimension of the entire fingerprint authentication sensor 40D.

Further, a liquid crystal layer 44H (display panel) is laminated on the non-printing portion of the second main surface 5 of the cover member 1 via the adhesive layer 45H. By incorporating the first main surface 3 of the cover member 1 outside and the housing 43H together with other components, a portable information terminal such as a smartphone is obtained. In this case, since the 1st recessed part 7 exists in the outer surface of a portable information terminal, even if there is no marking by printing, a sensor position is easily recognized.

(Example 6)
Another embodiment of the portable information terminal will be described. As shown in FIG. 23, the sensor surface of the fingerprint authentication sensor 40H is brought into contact with and secured to the second recess 14H of the cover member 1. A liquid crystal layer 44H (display panel) is laminated on the non-printing portion of the second main surface 5 of the cover member 1 via an adhesive layer 45H. The thickness in the Z direction of the adhesive layer 45H was about 100 μm. Further, the light source 48J was brought into contact with the other second concave portion 14H and fixed through the adhesive layer 49J. The thickness of the adhesive layer 49J in the Z direction was about 10 μm. A smartphone was manufactured by incorporating the cover member 1 into the housing 43J together with other components with the surface (first main surface 3) where the second recess 14H is not formed outside.

When the first concave portion 7H and the second concave portion 14H are irradiated by the light source 48J arranged on the display side of the cover member 1, light is scattered on the side surfaces thereof, so that the position of the fingerprint authentication sensor 40 is visually or tactilely sensed. The fingerprint can be read easily.

(Example 7)
The chemical strengthening simulation result which is Example 7 of the present invention will be described. Examples 1 to 4 are examples, and example 5 is a comparative example. In addition, this invention is not limited to a following example.

(Examples 1 to 4)
[Cover member]
A rectangular parallelepiped having a thickness T1 of 0.71 mm and a main surface of 70 mm × 150 mm was used as the glass substrate. 24A to 24D, the glass substrate is provided with a width W1 of the first recess 7 on the first main surface 3, a depth D1 of the first recess 7, and a second main surface. The first and

second recesses

7 and 14 are formed so that the width W2 of the second recess 14 and the depth D2 of the second recess 14 in the surface 5 are the values shown in the drawings, respectively, and the thin portion 21 is formed. The cover member 1 of Examples 1 to 4 having a thickness T2 of 0.15 mm was manufactured. The first and

second recesses

7 and 14 have a Y-direction width of 6.5 mm when the X-direction width is 23.5 mm and 8.5 mm when the X-direction width is 27.5 mm. .

For the cover members 1 of Examples 1 to 4, a protrusion was formed in the first recess 7 by the chemical strengthening simulation model shown below. That is, the thin portion 21 sandwiched between the first bottom surface portion 8 of the first concave portion 7 and the second bottom surface portion 15 of the second concave portion 14 is formed into a curved surface. The chemical strengthening simulation was performed as follows.

[Chemical strengthening simulation]
General-purpose structural analysis “Abacus” (Ver 6.13-2) was used for the simulation of chemical strengthening. Using “Abacus heat conduction analysis”, “potassium ion concentration distribution” was regarded as “temperature distribution”, and the calculation was unsteady. In addition, it calculated using the material coefficient in 100 mol% potassium nitrate molten salt in 425 degreeC shown in Table 1 using Formula (1) and Formula (2) for this simulation.

Here, C _x in the formula (1) is a potassium ion concentration [mol%], C ₀ is an initial potassium ion concentration [mol%], C _eq is an equilibrium potassium ion concentration [mol%], and D is a diffusion coefficient of potassium ion. [M ² / s] and H are mass transfer coefficients [m / s] of potassium ions, t: time [s], and x: depth [m] from the glass surface.

Here, σ _x in equation (2) is stress [Pa], B is an expansion coefficient, E is Young's modulus [Pa], ν is Poisson's ratio, and C _avg is an average potassium concentration [mol%]. ).

Here, L in the formula (3) is a half thickness [m], and x is a depth [m] from the glass surface.

(Example 5)
A rectangular parallelepiped having a thickness of 0.71 mm and a main surface of 70 mm × 150 mm was used as the glass substrate. The first and

second recesses

7 and 14 having the same size as that of Example 4 in FIG. In Example 5, no chemical strengthening simulation was required because no chemical strengthening was performed.

As shown in FIG. 25, the straight line connecting the both ends of the first bottom surface portion 8 in the thickness direction sectional view of the cover member 1 (two points where the first bottom surface portion 8 and the first connection surface portion 11 are connected). Is defined as a first reference line L1. The second connection surface portion 18 connects the opening edge of the second recess 14 and the outer edge of the second bottom surface portion 15. Of the points where the line parallel to the first reference line L1 is in contact with the curve constituting the first bottom surface portion 8, the point that is farthest from the first reference line L1 is defined as the first point A1, and the first point The length of the perpendicular (distance H1) from A1 to the first reference line L1 was determined. The results are shown in Table 2.

Since Example 5 was an unstrengthened sample, there was no protrusion in the first concave portion 7 (the thin portion 21 remained flat), and the length of the perpendicular was 0 μm. On the other hand, in Examples 1 to 4, the thin-walled portion 21 had a curved plate shape, and a protruding portion having a desired perpendicular length was obtained. From the above, it was found that Examples 1 to 4 corresponded to Examples of the present invention, and Example 5 corresponded to Comparative Examples of the present invention.
And actually, when the cover glass provided with the protruding portion as in Example 4 corresponding to the embodiment was produced, with respect to the cover member provided with the protruding portion, the protruding portion can be recognized with a finger, and a device such as a sensor is provided. The position could be recognized even when combined. On the other hand, in Example 5 corresponding to the comparative example, since it was not strengthened, the scratch resistance was low, and the touch feeling of the flat portion was poor and did not fit the finger.

[Modification]
The present invention is not limited to the above embodiment, and various improvements and design changes can be made without departing from the gist of the present invention. In addition, specific procedures for carrying out the present invention, The structure and the like may be changed as long as the object of the present invention can be achieved.

(Cover member having a bent portion)
The cover member having a bent portion includes at least one bent portion. A shape in which a bent portion and a flat portion are combined, a shape in which the entire portion is a bent portion, and the like can be mentioned, but the shape is not particularly limited as long as the bent portion is provided. Recently, when a cover member having a bent portion is used for a display device, various devices (such as a television, a personal computer, a smartphone, a car navigation system, etc.) in which the display surface of the display panel is curved have appeared. The bent portion can be manufactured according to the shape of the display panel, the shape of the casing of the display panel, and the like. “Flat part” means a part having an average curvature radius of more than 1000 mm, and “bent part” means a part having an average curvature radius of 1000 mm or less.

(Surface roughness etc.)
The roughness of the first bottom surface portion, the second bottom surface portion, and the first main surface and the second main surface of the printed layer in the thin portion of the cover member is not limited to the arithmetic average roughness Ra as described above. For example, in the case of the root mean square roughness Rq, 0.3 nm or more and 100 nm or less is preferable. When Rq is 100 nm or less, it becomes difficult to feel roughness, and when Rq is 0.3 nm or more, the friction coefficient of the glass surface becomes appropriate, and the slipperiness of a finger or the like is improved. In the case of the maximum height roughness Rz, 0.5 nm or more and 300 nm or less is preferable. When Rz is 300 nm or less, it becomes difficult to feel roughness, and when Rz is 0.5 nm or more, the friction coefficient of the glass surface becomes appropriate, and the slipperiness of a finger or the like is improved.

In the case of the maximum section height roughness Rt, 1 nm or more and 500 nm or less are preferable. When Rt is 500 nm or less, it becomes difficult to feel roughness, and when Rt is 1 nm or more, the friction coefficient of the glass surface becomes appropriate, and the slipperiness of a finger or the like is improved. In the case of the maximum peak height Rp, 0.3 nm or more and 500 nm or less are preferable. When Rp is 500 nm or less, it becomes difficult to feel roughness. When Rp is 0.3 nm or more, the friction coefficient of the glass surface becomes appropriate, and the slipperiness of a finger or the like is improved. In the case of the maximum valley depth roughness Rv, 0.3 nm or more and 500 nm or less are preferable. When Rv is 500 nm or less, it becomes difficult to feel roughness, and when Rv is 0.3 nm or more, the friction coefficient of the glass surface becomes appropriate, and the slipperiness of a finger or the like is improved.

In the case of the average length roughness Rsm, 0.3 nm to 1000 nm is preferable. When Rsm is 1000 nm or less, it becomes difficult to feel roughness, and when Rsm is 0.3 nm or more, the friction coefficient of the glass surface becomes appropriate, and the slipperiness of a finger or the like is improved. When the kurtosis roughness is Rku, it is preferably 1 or more and 3 or less. When Rku is 3 or less, it becomes difficult to feel roughness. When Rku is 1 or more, the coefficient of friction of the glass surface becomes appropriate, and the slipperiness of a finger or the like is improved. In addition, there is no particular limitation on parameters that can be expressed by waviness such as Wa and express roughness. The skewness roughness Rsk is preferably −1 or more and 1 or less from the viewpoint of uniformity such as visibility and touch.

<Application>
The use of the cover member of the present invention is not particularly limited. Specific examples include transparent parts for vehicles (headlight covers, side mirrors, front transparent boards, side transparent boards, rear transparent boards, instrument panel surfaces, etc.), meters, architectural windows, show windows, and architectural interior members. , Exterior materials for buildings, displays (notebook computers, monitors, LCDs, PDPs, ELDs, CRTs, PDAs, etc.), LCD color filters, touch panel substrates, pickup lenses, optical lenses, eyeglass lenses, camera parts, video parts, CCDs Cover substrates, optical fiber end faces, projector parts, copier parts, transparent substrates for solar cells (cover members, etc.), mobile phone windows, backlight unit parts (light guide plates, cold cathode tubes, etc.), backlight unit parts LCD brightness enhancement film (prism, transflective film, etc.), LCD brightness enhancement film Lum, organic EL light-emitting element parts, inorganic EL light-emitting element parts, phosphor light-emitting element parts, optical filters, end faces of optical parts, illumination lamps, lighting fixture covers, amplified laser light sources, antireflection films, polarizing films, agricultural films Etc.

<Article>
The article of the present invention includes the cover member.
The article of the present invention may be composed of the cover member, or may further include a member other than the cover member.
Examples of the article of the present invention include those mentioned above as applications of the cover member, and devices including any one or more of them.
Examples of the device include a portable information terminal, a display device, a lighting device, and a solar cell module.
The article of the present invention is suitable for a portable information terminal and a display device because a concave portion is obtained and sensing sensitivity and visibility are good. In addition, a plurality of large concave portions are required for a cover member used for in-vehicle use, and high sensing sensitivity is required when a sensor is arranged. Further, a concave portion may be required for the cover member having a bent shape. The present invention can provide a cover member that can satisfy these requirements. From the above, the cover member of the present invention is suitable as a vehicle-mounted cover member.

When the article of the present invention is a display device, the article of the present invention includes a display panel for displaying an image and a cover member of the present invention provided on the viewing side of the display device body.
Examples of the display panel include a liquid crystal panel, an organic EL (electroluminescence) panel, and a plasma display panel. The cover member may be provided integrally with the display panel as a protective plate of the display device, and a sensor such as a touch panel sensor is disposed on the second main surface of the display panel, that is, display is performed between the cover member and the sensor. It is good also as a structure with a panel. Moreover, you may arrange | position a cover member in the visual recognition side of a display panel via a sensor.

According to the present invention, when a fingerprint authentication sensor is incorporated, a cover member capable of exhibiting a desired sensing capability, a portable information terminal or display device having the cover member, a glass substrate for extracting a plurality of cover members, and simple Cover member and glass substrate manufacturing method can be provided.

This application is based on Japanese Patent Application No. 2016-245540 filed on Dec. 19, 2016, the contents of which are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 1 ... Cover member 3,103 ... 1st main surface, 5,105 ... 2nd main surface, 7, 7A, 7B, 7C, 7D, 7G, 7H, 107 ... 1st recessed part, 8, 8A, 8B, 8C, 8D, 8G, 8H, 108 ... first bottom surface portion, 11, 11A, 11C, 11H, 111 ... first connection surface portion, 14, 14A, 14B, 14C, 14D, 14E, 14F, 14G, 14H, 114 ... second recess, 15, 15A, 15B, 15C, 15D, 15E, 15F, 15G, 15H, 115 ... second bottom surface portion, 18A, 18B, 18D, 18E, 18F, 18H, 118 ... first 2 connection surface portions, 21, 21A, 21B, 21C, 21D, 21E, 21F, 21H, 121... Thin portions, 22, 22A, 22B, 22C, 22D, 22E, 22F, 122. .

Claims

A cover member for protecting a protection object,
The first main surface of the cover member is provided with a first recess,
A second recess is provided at a position corresponding to the first recess on the second main surface,
The first concave portion includes a first bottom surface portion formed in a curved surface shape.
The first bottom surface portion is a curved surface protruding toward the first main surface side,
The cover member according to claim 1, wherein the first recess includes a first connection surface portion that connects an opening edge of the first recess and an outer edge of the first bottom surface portion.
The cover member according to claim 1, wherein the first bottom surface portion has a curved surface shape protruding toward the second main surface side.
A straight line connecting both ends of the first bottom surface in a cross-sectional view in the thickness direction of the cover member is a first reference line L1, a point on the first bottom surface that is farthest from the first reference line L1. Is the first point A1,
The cover member according to claim 2 or 3, wherein a distance H1 from the first reference line L1 to the first point A1 is 5 µm or more.
A straight line connecting both ends of the first bottom surface in a cross-sectional view in the thickness direction of the cover member is a first reference line L1, a point on the first bottom surface that is farthest from the first reference line L1. Is a first point A1, and a point corresponding to the first point A1 in the second recess is a corresponding point B2,
An absolute value of a difference between a depth J1 from the first main surface to the first point A1 and a depth J2 from the second main surface to the corresponding point B2 is 0.1 µm or more. The cover member according to any one of 2 to 4.
The cover member according to any one of claims 1 to 4, wherein a curved second bottom surface portion is provided at a position corresponding to the first bottom surface portion in the second recess.
The second bottom surface portion has a curved surface shape protruding toward the second main surface side,
The cover member according to claim 6, wherein the second recess includes a second connection surface portion that connects an opening edge of the second recess and an outer edge of the second bottom surface portion.
The cover member according to claim 6, wherein the second bottom surface portion has a curved surface shape protruding toward the first main surface side.
A straight line connecting both ends of the second bottom surface portion in a sectional view in the thickness direction of the cover member is a second reference line L2, a point on the second bottom surface portion that is farthest from the second reference line L2. Is the second point A2,
The cover member according to claim 7 or 8, wherein a distance H2 from the second reference line L2 to the second point A2 is 5 µm or more.
A second bottom surface portion protruding in a curved shape in the same direction as the first bottom surface portion is formed at a position corresponding to the first bottom surface portion in the second recess, and the second bottom surface portion The cover member according to any one of claims 1 to 5, wherein a thin portion is configured by a region sandwiched between the first bottom surface portion.
The cover member according to any one of claims 1 to 10, wherein the first recess overlaps the second recess in a plan view of the cover member.
The cover member according to any one of claims 1 to 11, wherein a distance between a gravity center position of the first recess and a gravity center position of the second recess in a plan view of the cover member is 100 µm or less.
The cover member according to any one of claims 1 to 12, wherein a potassium ion concentration on the first main surface and the second main surface is higher than a potassium ion concentration at a thickness direction center of the cover member.
The cover member according to any one of claims 1 to 13, wherein the protection target is a portable information terminal.
A portable information terminal having the cover member according to any one of claims 1 to 14.
A cover member manufacturing method for manufacturing a cover member for protecting a protection object from a glass substrate,
Forming a first recess in the first main surface of the glass substrate, and forming a second recess in a position corresponding to the first recess in the second main surface;
Chemically strengthening the glass substrate on which the first recess and the second recess are formed;
When forming the concave portion, the first concave portion includes a planar first bottom surface portion, and the second concave portion is provided at a position corresponding to the first bottom surface portion. A planar second bottom surface portion that constitutes a thin portion by a region sandwiched between the bottom surface portion and the first recess is overlapped with the second recess in a plan view. The manufacturing method of the cover member to do.
A cover member manufacturing method for manufacturing a cover member for protecting a protection object from a glass substrate,
Forming a first recess in the first main surface of the glass substrate, and forming a second recess in a position corresponding to the first recess in the second main surface;
Chemically strengthening the glass substrate on which the first recess and the second recess are formed;
When forming the recess, the first recess connects the planar first bottom surface portion, the opening edge of the first recess, and the outer edge of the first bottom surface portion. A planar second bottom surface that is formed by a region sandwiched between the first bottom surface portion and the second recess is provided at a position corresponding to the first bottom surface portion. And a second connection surface portion that connects the opening edge of the second recess and the outer edge of the second bottom surface portion, the depth of the first bottom surface portion and the depth of the second bottom surface portion. A process for producing a cover member, wherein the treatment is performed so as to be different.
A cover member manufacturing method for manufacturing a cover member for protecting a protection object from a glass substrate,
Forming a first recess in the first main surface of the glass substrate, and forming a second recess in a position corresponding to the first recess in the second main surface;
When forming the recess, the first recess includes a curved first bottom surface protruding toward the first main surface, and the second recess is formed on the first bottom surface. Forming a curved surface projecting toward the first main surface at a corresponding position, and performing processing so as to include a second bottom surface portion that forms a thin portion by a region sandwiched between the first bottom surface portion. The manufacturing method of the cover member characterized by these.