KR102454633B1 - Curved Tempered Glass And Method For Manufacturing The Same - Google Patents

Abstract

The present invention relates to a tempered glass having a stress layer formed on its surface, comprising: a flat portion; and at least one curved portion extending from an edge of the flat portion and bent, wherein a thickness of the curved portion is different from a thickness of the flat portion.

Description

Tempered glass having a curved surface and manufacturing method thereof

The present invention relates to a tempered glass having a curved surface and a method for manufacturing the same.

In order to increase the mechanical strength of brittle glass, tempered glass with its surface strengthened has recently been popularized, and the field of application thereof is also diversifying. For example, with the development of portable information processing devices, the demand for various display devices is rapidly increasing. The display device includes a protective cover for protecting internal elements of the display device, and glass may be used as a material of the protective cover. When glass is used as a protective cover, there is an advantage in that weather resistance, scratch resistance, and high transmittance can be secured, but there is a disadvantage that it is exposed to the outside and can be easily broken by an impact caused by an external factor. In order to solve these shortcomings, studies for securing the mechanical strength of glass are being actively conducted.

As a method for strengthening glass, a physical strengthening method is known. The physical strengthening method is a method of heating the glass to a high temperature for a certain period of time and then rapidly cooling the surface of the glass by air cooling, so that a compressive stress is generated on the surface of the glass and a tensile stress is generated inside the glass.

However, the physical strengthening method using the temperature difference between the inside and the outside has a limit in strengthening the thin film type glass. That is, in the case of thin glass, it is difficult to form a compressive stress on the surface of the glass plate since a temperature difference between the surface and the inside does not easily occur. The display device may include a touch screen panel capable of recognizing a user's touch and/or gesture to sense the user's hand or movement of a conductor. The glass protecting the display device is required to be formed as a thin film in order to increase touch sensing sensitivity. Accordingly, there is a limit to using a physical strengthening method to form a thin tempered glass.

On the other hand, as glass is applied in various fields, glass having a curved surface corresponding to various needs of users has been popularized. For example, as a curved display device is provided, as a protective cover corresponding to the curved display device, glass having a curved portion is required.

In the prior art of manufacturing glass including curved parts, a mechanical processing method using a traditional lathe and automatic lathe (CNC), a press (55) that heats the glass to a certain temperature or more and then presses it using a mold corresponding to the shape of the glass including the curved part (55) a molding method, and a slumping molding method using gravity and a mold at high temperature. However, the glass provided by this method has problems of poor quality, low productivity and low yield. In addition, there is also a problem of how the tempered glass can be processed.

Therefore, the development of a method for manufacturing a tempered glass capable of processing a curved portion while being able to increase mechanical strength by strengthening the thin glass is required.

An object of the present invention is to provide a tempered glass having a curved portion by chemically strengthening the thin glass and performing a removal process on a part thereof. In addition, an object of the present invention is to provide a tempered glass having a reduced step difference that may be formed at the boundary between the flat portion and the curved portion. Another object of the present invention is to provide a tempered glass in which a plurality of curved portions are defined.

In order to achieve the above or other objects, the present invention relates to a tempered glass having a stress layer formed on its surface, comprising: a flat portion; and at least one curved portion extending from an edge of the flat portion and bent, wherein a thickness of the curved portion is different from a thickness of the flat portion.

Tempered glass manufacturing method according to an embodiment of the present invention includes a first step of preparing a glass substrate in which a flat portion and a plurality of curved portions positioned outside the flat portion are defined, a chamfering process in an area where the adjacent curved portions overlap A second step of performing a third step of forming a stress layer on the surface of the glass substrate by strengthening the glass substrate, and a fourth step of performing an etching process or a polishing process on at least a portion of the surface of the curved portion includes The curved portion is bent during the etching process or the polishing process.

Tempered glass manufacturing method according to another embodiment of the present invention is a first step of preparing a glass substrate in which a flat portion and a plurality of curved portions located outside the flat portion are defined; A second step of forming a stress layer on the surface, a third step of performing a chamfering process on a region where the adjacent curved portions overlap, and a fourth step of performing an etching process or a polishing process on at least a portion of the surface of the curved portion includes The curved portion is bent during the etching process or the polishing process.

The tempered glass according to the present invention is strengthened by a chemical strengthening method, so that it is possible to strengthen the thin glass substrate, reduce manufacturing cost and manufacturing time, and improve productivity and yield. In addition, it has the advantage that it can be strengthened without additional deformation or physical processing of the glass substrate.

The present invention, unlike the processing methods performed to form the conventional curved portion, by forming the curved portion through the etching process, it is possible to improve productivity and yield, it is possible to prevent deterioration of the quality of the processed glass, manufacturing cost and manufacturing It has the effect of shortening the time. In addition, according to the method for manufacturing tempered glass according to an embodiment of the present invention, since the designer can process the shape of the final product differently by adjusting the process conditions, various design changes are possible compared to the processing method using a conventional mold, etc. and design changes are relatively easy.

According to the present invention, by reducing the step that may be formed along the boundary between the flat portion and the curved portion during the process, it is possible to prevent the step from being visually recognized from the outside. In addition, according to the present invention, it is possible to prevent a problem of a decrease in visibility that may occur due to the stacking of foreign substances on the step portion.

The present invention can provide a tempered glass in which a plurality of curved portions are defined. In the present invention, an overlapping region in which adjacent curved portions overlap may be removed by performing a chamfering process. Accordingly, it is possible to prevent the curved portions from being bent in a bending direction and curvature different from the designer's intention by the overlapping area.

1 is a view showing a tempered glass according to a first embodiment of the present invention.
2 to 6 are cross-sectional views illustrating a process for manufacturing a tempered glass according to an embodiment of the present invention.
7 is an enlarged view of an AR region in FIG. 6 .
8 to 12 are cross-sectional views illustrating a process for manufacturing a tempered glass according to another embodiment of the present invention.
13 is a view showing a tempered glass according to a second embodiment of the present invention.
14 is a cross-sectional view for explaining a tempered glass and a process for manufacturing the same according to an embodiment of the present invention.
15 is a cross-sectional view for explaining a tempered glass and a process for manufacturing the same according to another embodiment of the present invention.
16 to 19 are cross-sectional views illustrating a process for manufacturing a tempered glass according to another embodiment of the present invention.
20 is an enlarged view of the AR′ region in FIG. 19 .
21 and 22 are views schematically showing a tempered glass according to a third embodiment of the present invention.
23 is a flowchart for explaining a method of manufacturing a tempered glass according to an embodiment of the present invention.
24 is a flowchart for explaining a method of manufacturing a tempered glass according to another embodiment of the present invention.
25 is a flowchart for explaining a method of manufacturing a tempered glass according to another embodiment of the present invention.
26 and 27 are views for explaining the positions of the flat portion and the curved portion defined in the tempered glass according to the third embodiment of the present invention.
28 and 29 are views for explaining a chamfering process performed on the tempered glass according to the third embodiment of the present invention.
30 is a view for explaining an application field of the tempered glass according to the first, second, and third embodiments of the present invention.

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted. The suffix "part" for components used in the following description is given or mixed in consideration of only the ease of writing the specification, and does not have a meaning or role distinct from each other by itself. In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed herein is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention , should be understood to include equivalents or substitutes.

Terms including ordinal numbers such as first, second, etc. may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as “comprises” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that this does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

<First embodiment>

Hereinafter, a tempered glass and a manufacturing method thereof according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 6 .

1 is a view showing a tempered glass according to a first embodiment of the present invention.

Referring to FIG. 1 , the tempered glass 1 according to the first embodiment of the present invention includes a flat portion FA and a curved portion BA. The flat portion FA means an area having a planar shape in the tempered glass 1 according to the present invention. The curved portion BA refers to a region in which the tempered glass 1 according to the present invention is bent to have a curved shape. The curved portion BA is provided to extend from at least one side of the flat portion FA. The flat portion FA has a first thickness t1 , and the curved portion BA has a second thickness t2 . At the boundary between the flat portion FA and the curved portion BA, a step 30 due to a difference in thickness between the flat portion FA and the curved portion BA is formed.

2 to 6, a method of manufacturing the tempered glass 1 according to an embodiment of the present invention will be described. 2 to 6 are cross-sectional views illustrating a process for manufacturing a tempered glass according to an embodiment of the present invention.

Referring to FIG. 2 , a glass substrate 10 for strengthening treatment is provided. A flat portion FA and a curved portion BA extending from at least one side of the flat portion FA are defined in the glass substrate 10 . The planar part FA refers to an area having a planar shape after the final process. The curved portion BA refers to an area having a curved shape that is bent after a final process.

Referring to FIG. 3 , a strengthening process of strengthening the glass substrate 10 in which the flat portion FA and the curved portion BA is defined is performed. The strengthening process is performed according to a chemical strengthening method. The chemical strengthening method is a method of forming a stress layer on the glass surface layer through the substitution of ions. The stress layer may be a compressive stress layer 20 . The driving force for ion displacement can be governed by the diffusion coefficient of individual ions with diffusion by concentration gradient. For example, by immersing the glass substrate 10 in a salt bath (molten potassium nitrate) at 400 to 500° C. for a certain time, alkali metal ions (sodium ions) with a small ionic radius present in the surface layer of the glass substrate 10 can be induced to be replaced with an alkali metal ion (potassium ion) having a relatively large ionic radius. Accordingly, the compressive stress layer 20 is formed on the surface of the glass substrate 10 . The compressive stress layer 20 refers to an outer surface layer of the glass substrate 10 formed by intrusion of relatively large ions into the surface of the glass substrate 10 by ion exchange. As the compressive stress layer 20 is formed, the strength of the glass substrate 10 vulnerable to tensile stress can be increased. The strength of the glass substrate 10 may be further improved as the depth of the compressive stress layer 20 (Depth Of Layer, hereinafter referred to as 'DOL') (D) is deeper.

Tempered glass 1 according to an embodiment of the present invention is strengthened by a chemical strengthening method rather than a physical strengthening method, so that the strengthening treatment in the thin glass substrate 10 is possible, and the manufacturing cost and manufacturing time can be reduced, Productivity and yield can be improved. In addition, it has the advantage of being able to strengthen the glass substrate 10 without additional deformation or physical processing.

Referring to FIG. 4 , a mask 50 is provided on the tempered glass substrate 10 . The mask 50 includes an opening OR and a non-opening NOR. The mask 50 may be made of a material that is not deformed by the etchant 60 . The mask 50 surrounds the entire surface along the periphery of the tempered glass substrate 10 , and exposes one of the upper and lower surfaces of the curved portion BA through the opening OR. The surface of the curved portion BA exposed through the opening OR may be determined according to a bending direction intended by a designer. In other words, the bending direction of the curved portion BA may be determined according to the position of the opening OR. The position of the opening may determine the bending direction. For example, the designer may arrange the opening OR of the mask 50 to expose the lower surface of the curved portion BA in order to bend the curved portion BA in the downward direction. Hereinafter, a case in which the opening OR is disposed to expose the lower surface in order to bend the curved portion BA in the lower direction will be described as an example.

Referring to FIG. 5 , an etching process of applying an etchant 60 to the surface of the glass substrate 10 provided with the mask 50 is performed. The etching process may include all known processes capable of removing the surface of the glass substrate 10 . The etching solution 60 is preferably applied in a direction perpendicular to the surface exposed by the opening OR. Through the etching process, a portion of the thickness of the curved portion BA exposed to the outside by the opening OR is removed.

Referring to FIG. 6 , when the lower surface of the curved portion BA is removed by the etching process, a difference in DOL(D) occurs between the lower surface to which the etching process is performed and the upper surface to which the etching process is not performed. As the compressive stress formed on the lower surface of the curved portion BA is reduced compared to the compressive stress formed on the upper surface of the curved portion BA, the curved portion BA is bent downward in response to the difference in compressive stress. At this time, as the etching process is locally performed on the curved portion BA, the thickness t2 of the curved portion BA is reduced compared to the thickness t1 of the flat portion FA. Accordingly, the step 30 is generated at the boundary between the curved portion BA and the flat portion FA.

Unlike the conventional processing methods performed to form the curved portion BA, the present invention can improve productivity and yield by forming the curved portion BA through an etching process, and prevent deterioration of the quality of the processed glass. and has the effect of reducing manufacturing cost and manufacturing time. In addition, in the method for manufacturing tempered glass according to an embodiment of the present invention, the designer adjusts the process conditions such as the strengthening process time and the depth of the DOL, the type and application amount of the etchant, and the etching process time to change the shape of the final result. can be processed Accordingly, various design changes are possible compared to a processing method using a conventional mold or the like, and the design change is relatively easy.

For example, in the method of manufacturing the tempered glass 1 according to an embodiment of the present invention, the degree of bending of the curved portion BA may be varied by varying the etching amount. Table 1 shows that when the length (L) of the curved portion (BA) is 10 mm in the glass of the 0.1T thickness (t) as the reference (REF) (see FIG. 3 ), only the etching amount is adjusted in a state where other conditions are constant This is experimental data showing that the degree of bending of the curved portion BA can be adjusted. In the table, the etching amount means the thickness of the lower surface of the curved portion BA removed through the etching process.

0.1T Glass DOL(D)(㎛) Etched amount (㎛) Curved surface (BA)(mm) t (thickness) L (length) REF. - - 0.10 10.00 One
30
20 4.32 8.31 2 30 4.95 7.91 3 40 6.03 7.11

As another example, in the method of manufacturing the tempered glass 1 according to an embodiment of the present invention, the degree of bending of the curved portion BA may be varied by changing the DOL(D). Table 2 shows the reference (REF) when the length (L) of the curved portion (BA) is 10 mm in the glass of the 0.1T thickness (t) (see FIG. 3 ), and the DOL (D) under other conditions constant It is experimental data showing that the degree of bending of the curved portion BA can be adjusted by adjusting the

0.1T Glass DOL(D)(㎛) Etched amount (㎛) Curved surface (BA)(mm) t (thickness) L (length) REF. - - 0.10 10.00 One 10
20

2.23 9.24 2 20 3.16 8.65 3 30 4.32 8.31 4 40 4.15 7.91

As another example, in the method of manufacturing the tempered glass 1 according to an embodiment of the present invention, the degree of bending of the curved portion BA may be varied by changing the etching amount and the DOL(D). Table 3 is a reference (REF) when the length (L) of the curved portion (BA) is 10mm in the glass of the 0.1T thickness (t) (see FIG. 3 ), the etching amount and / in other conditions constant Alternatively, it is experimental data showing that the degree of bending of the curved portion BA can be adjusted by adjusting the DOL (D).

0.1T Glass DOL(D)(㎛) Etched amount (㎛) Curved surface (BA)(mm) t (thickness) L (length) REF. - - 0.10 10.00 One
10
20 2.23 9.24 2 30 2.81 8.38 3 40 3.58 7.73 4
20
20 3.16 8.65 5 30 3.68 8.37 6 40 4.84 7.97 7
30
20 4.32 8.31 8 30 4.95 7.91 9 40 6.03 7.11 10
40
20 4.15 7.91 11 30 4.81 7.43 12 40 6.35 6.47

The relationship between the surface thickness (etched amount) of the curved portion BA removed through the etching process and the compressive stress layer 20 formed during chemical strengthening will be described with reference to FIG. 7 . 7 is an enlarged view of an AR region in FIG. 6 .

As shown in FIG. 7 and the aforementioned experimental example, as the etching process is performed on the lower surface of the curved portion BA, the thickness of the compressive stress layer 20 formed on the lower surface of the curved portion BA may be reduced. ((a) of FIG. 7), the compressive stress layer 20 may be removed ((b) of FIG. 7), and may be overetched beyond the compressive stress layer 20 ((c) of FIG. 7) ). The amount of etching may be adjusted to correspond to the degree of bending being the target according to the intention of the designer. However, the etching amount is preferably adjusted appropriately so as to prevent a decrease in strength caused by the complete removal of the compressive stress layer 20 formed on the lower surface of the curved portion BA.

Hereinafter, a tempered glass and a manufacturing method thereof according to another embodiment of the present invention will be described with reference to FIGS. 8 to 12 . 8 to 12 are cross-sectional views illustrating a process for manufacturing a tempered glass according to another embodiment of the present invention.

Referring to FIG. 8 , a glass substrate 10 for strengthening treatment is provided. A flat portion FA and a curved portion BA extending from at least one side of the flat portion FA are defined in the glass substrate 10 . The planar part FA refers to an area having a planar shape after the final process. The curved portion BA refers to an area having a curved shape that is bent after a final process.

Referring to FIG. 9 , a strengthening process of strengthening the glass substrate 10 in which the flat portion FA and the curved portion BA is defined is performed. The strengthening process is performed according to a chemical strengthening method. The chemical strengthening method is a method of forming a stress layer on the glass surface layer through the substitution of ions. The stress layer may be a compressive stress layer 20 . The driving force for ion displacement can be governed by the diffusion coefficient of individual ions with diffusion by concentration gradient. For example, by immersing the glass substrate 10 in a salt bath (molten potassium nitrate) at 400 to 500° C. for a certain time, alkali metal ions (sodium ions) with a small ionic radius present in the surface layer of the glass substrate 10 can be induced to be replaced with an alkali metal ion (potassium ion) having a relatively large ionic radius. Accordingly, the compressive stress layer 20 is formed on the surface of the glass substrate 10 . The compressive stress layer 20 refers to an outer surface layer of the glass substrate 10 formed by intrusion of relatively large ions into the surface of the glass substrate 10 by ion exchange. As the compressive stress layer 20 is formed, the strength of the glass substrate 10 vulnerable to tensile stress can be increased. The strength of the glass substrate 10 may be further improved as the DOL(D) of the compressive stress layer 20 is deeper.

Tempered glass 1 according to another embodiment of the present invention is strengthened by a chemical strengthening method rather than a physical strengthening method, so that the strengthening treatment in the thin glass substrate 10 is possible, and the manufacturing cost and manufacturing time can be reduced, Productivity and yield can be improved. In addition, it has the advantage of being able to strengthen the glass substrate 10 without additional deformation or physical processing.

Referring to FIG. 10 , a polishing pad 53 and a press 55 for applying a load to the polishing pad 53 are provided on the tempered glass substrate 10 . The polishing pad 53 is disposed on any one of the upper and lower surfaces of the curved portion BA. The surface of the curved portion BA on which the polishing pad 53 is disposed may be determined according to a bending direction intended by a designer. In other words, the bending direction of the curved portion BA may be determined according to a position where the polishing pad 53 is disposed. For example, the designer may arrange the polishing pad 53 on the upper surface of the curved portion BA to bend the curved portion BA in an upward direction. Hereinafter, a case in which the polishing pad 53 is disposed on the upper surface of the curved portion BA in order to bend the curved portion BA in the upward direction will be described as an example.

Referring to FIG. 11 , a polishing process is performed on the surface of the glass substrate 10 that has been strengthened. The upper surface of the curved portion is in contact with the polishing pad 53 . A polishing load is applied to the upper surface of the curved portion from the press 55 through the polishing pad 53 . The polishing pad 53 may be repeatedly operated in a specific direction as shown. A portion of the upper surface of the curved portion BA is removed by repeated operation of the polishing pad 53 . In order to continuously perform the polishing process, the polishing liquid and the cleaning liquid may be selectively supplied during the operation of the polishing pad 53 , thereby increasing process efficiency and yield. Process conditions such as polishing load, polishing rate, and polishing time may be appropriately selected according to the strength of the glass substrate and the like. As for the shape and structure of the polishing pad 53, a polishing process method, and the like, a known technique may be used.

Referring to FIG. 12 , when the upper surface of the curved portion BA is removed by the polishing process, a difference in DOL (D) occurs between the upper surface on which the polishing process is performed and the lower surface on which the polishing process is not performed. As the compressive stress formed on the upper surface of the curved portion BA is reduced compared to the compressive stress formed on the lower surface of the curved portion BA, the curved portion BA is bent upward in response to the difference in compressive stress. In this case, as the polishing process is locally performed on the curved portion BA, the thickness t2 of the curved portion BA is reduced compared to the thickness t1 of the flat portion FA. Accordingly, the step 30 is generated at the boundary between the curved portion BA and the flat portion FA.

The curved portion BA of the tempered glass according to the present invention may be formed by performing a polishing process with high precision. The method for manufacturing tempered glass according to another embodiment of the present invention may provide a tempered glass having a curved portion BA having improved flatness and smoothness by using a polishing process.

<Second embodiment>

Unlike the first embodiment, the second embodiment of the present invention is characterized in that it provides a tempered glass 201 in which the step 30 formed at the boundary between the flat portion FA and the curved portion BA is reduced. The step 30 formed at the boundary between the flat portion FA and the curved portion BA may be recognized by the naked eye from the outside, and may be a factor deteriorating the aesthetics of the tempered glass 201 . In addition, a foreign material may be laminated on the portion of the step 30 formed at the boundary between the flat portion FA and the curved portion BA during a manufacturing process and/or a distribution process, and the foreign material may be visually inspected through the tempered glass 201 . Visibility of the incident light may be reduced. In order to solve this problem, hereinafter, the tempered glass 201 and a method of manufacturing the tempered glass 201 in which the step 30 that may be formed at the boundary between the flat portion FA and the curved portion BA is reduced will be described.

13 is a view showing a tempered glass according to a second embodiment of the present invention.

Referring to FIG. 13 , the tempered glass 201 according to the second embodiment of the present invention includes a flat portion FA and a curved portion BA. The flat portion FA refers to an area having a planar shape in the tempered glass 201 according to the present invention. The curved portion BA refers to a region in which the tempered glass 201 according to the present invention is bent to have a curved shape. The curved portion BA extends from the flat portion FA in at least one direction. An inclination between one surface of the flat portion FA and one surface of the adjacent curved portion BA is gentle. To this end, the curved portion BA has a thickness different from that of the flat portion FA. For example, the flat portion FA may have a first thickness t1 and the curved portion BA may have a thickness different from that of the flat portion FA, but may have different thicknesses t2 and t3 depending on the location. have.

With reference to FIG. 14 , the tempered glass 201 and a method of manufacturing the same according to an embodiment of the present invention will be described. 14 is a cross-sectional view for explaining a tempered glass and a process for manufacturing the same according to an embodiment of the present invention.

14, an embodiment of the present invention, the tempered glass 1 according to the first embodiment, that is, a glass substrate having a step 30 at the boundary between the flat portion FA and the curved portion BA ( On the premise of 210), a tempered glass 201 having a reduced step 30 is provided. 2 to 6, or 8 to 12, the tempered glass 201 formed through the process, an etching process or a polishing process is performed on any one surface of the curved portion BA, the thickness and the flat portion of the curved portion BA The thickness of (FA) becomes different. That is, a portion of the thickness of one side of the curved portion BA is removed, so that the thickness t2 of the curved portion BA is reduced compared to the thickness t1 of the flat portion FA. Accordingly, a step 30 having a steep inclination is formed at the boundary between the curved portion BA and the flat portion FA.

An additional polishing process is performed on the stepped portion formed at the boundary between the flat portion FA and the curved portion BA. The further polishing process may be performed using known apparatus and methods. By the additional polishing process, one surface of the glass substrate 210 having a step is removed. The removed one side surface may be a compressive stress layer 220 . As a partial region of the compressive stress layer 220 is removed, the degree of bending of the curved portion BA may vary. For convenience of description, a region in which an additional polishing process is performed among the curved portion BA will be defined as a first curved portion BA1 . In other words, the curved portion BA is defined as a first curved portion BA1 adjacent to the flat portion FA and a second curved portion BA2 spaced apart from the flat portion FA, and the first curved portion BA1 . denotes an area in which an additional polishing process is performed. In this case, the thickness of the curved portion BA is formed to be thinner than the thickness of the flat portion FA, and the thickness of the first curved portion BA1 is gradually reduced as the distance from the flat portion FA increases, and the second curved surface The thickness of the portion BA2 is constant.

Since the additional polishing process performed on the first curved portion BA1 aims to remove the step 30 , it may be sufficient to remove only the compressive stress layer 220 in a narrow area. Therefore, it should be noted that the additional polishing process may not affect the degree of bending.

The tempered glass 201 according to an embodiment of the present invention in which the step 30 is reduced through an additional polishing process may prevent the step 30 from being visually recognized from the outside. In addition, it is possible to prevent a problem of deterioration of visibility that may occur due to the stacking of foreign substances on the step 30 portion.

Referring to FIG. 15 , a tempered glass 201 and a manufacturing method thereof according to another embodiment of the present invention will be described. 15 is a cross-sectional view for explaining a tempered glass and a process for manufacturing the same according to another embodiment of the present invention.

15, another embodiment of the present invention, the tempered glass 1 according to the first embodiment, that is, a glass substrate having a step 30 at the boundary between the flat portion FA and the curved portion BA ( On the premise of 210), a tempered glass 201 having a reduced step 30 is provided. 2 to 6, or 8 to 12, the tempered glass 201 formed through the process, an etching process or a polishing process is performed on any one surface of the curved portion BA, the thickness and the flat portion of the curved portion BA The thickness of (FA) becomes different. That is, a portion of the thickness of one side of the curved portion BA is removed, so that the thickness t2 of the curved portion BA is reduced compared to the thickness t1 of the flat portion FA. Accordingly, a step 30 having a steep inclination is formed at the boundary between the curved portion BA and the flat portion FA.

In order to reduce the step 30 , a process of forming the filling layer 240 on the curved portion BA of the glass substrate 210 is performed. The filling layer 240 serves to fill the step 30 formed at the boundary between the curved portion BA and the flat portion FA of the glass substrate 210 . That is, the filling layer 240 is positioned to fill the step 30 formed along the boundary between the curved portion BA and the flat portion FA, so that one surface of the flat portion FA and the adjacent curved portion BA are formed. Make sure one side has a gentle slope.

The filling layer 240 may be formed on the entire surface of one side of the curved portion BA in which the step 30 is formed. In this case, the glass substrate 210 and the filling layer 240 are laminated on the curved portion BA of the tempered glass 201 , and the thicknesses t2 and t3 of the curved portion BA are determined from the flat portion FA. As the distance increases, it gradually decreases (FIG. 15(a)). The filling layer 240 may be formed only on a partial surface of one side of the curved portion BA on which the step 30 is formed. That is, the curved portion BA may be defined as a first curved portion BA1 adjacent to the flat portion FA and a second curved portion BA2 spaced apart from the flat portion FA. In this case, the first curved portion BA1 refers to an area in which the filling layer 240 is stacked on the glass substrate 210 . In this case, the thickness of the curved portion BA of the tempered glass 201 is formed to be thinner than the thickness of the flat portion FA, and the thickness t2 of the first curved portion BA1 may be farther from the flat portion FA. It gradually decreases, and the thickness t3 of the second curved portion BA2 is constant (FIG. 15(b)).

The filling layer 240 is preferably a transparent resin that transmits light. For example, the filling layer 240 may include a transparent acryl-based resin, an epoxy-based resin, and a urethane-based resin. In addition, the filling layer 240 is preferably formed of a material having good adhesion to the glass substrate 210 . The filling layer 240 is preferably formed of a material having excellent optical properties in order to prevent a problem of deterioration in visibility of light incident to the user's naked eye through the glass substrate 210 and the filling layer 240 . In addition, the filling layer 240 is preferably a material having a transmittance and a refractive index equal to that of the glass substrate 210 .

The tempered glass 201 according to another embodiment of the present invention in which the step 30 is reduced through the formation of the filling layer 240 may prevent the step 30 from being visually recognized from the outside. In addition, it is possible to prevent a problem of deterioration of visibility that may occur due to the stacking of foreign substances on the step 30 portion.

The filling layer 240 may be formed on the curved portion BA to function as a buffer layer absorbing an external force that may act on the tempered glass 201 . In detail, the curved portion BA of the tempered glass 201 according to the present invention may have a lower strength than the surrounding area by removing a portion of the compressive stress layer 220 . In this situation, another embodiment of the present invention further forms the filling layer 240 on the curved portion BA, thereby reducing the deformation or cracking of the curved portion BA due to an external force provided from the outside. Tempered glass 201 can provide

Hereinafter, the tempered glass 201 and a method of manufacturing the same according to another embodiment of the present invention will be described with reference to FIGS. 16 to 19 . 16 to 19 are cross-sectional views illustrating a process for manufacturing a tempered glass according to another embodiment of the present invention.

Referring to FIG. 16 , a glass substrate 210 for strengthening treatment is provided. A flat portion FA and a curved portion BA extending from at least one side of the flat portion FA are defined in the glass substrate 210 . The planar part FA refers to an area having a planar shape after the final process. The curved portion BA refers to an area having a curved shape that is bent after a final process.

Referring to FIG. 17 , a strengthening process of strengthening the glass substrate 210 in which the flat portion FA and the curved portion BA are defined is performed. The strengthening process is performed according to a chemical strengthening method. The chemical strengthening method is a method of forming a stress layer on the glass surface layer through the substitution of ions. The stress layer may be a compressive stress layer 220 . The driving force for ion displacement can be governed by the diffusion coefficient of individual ions with diffusion by concentration gradient. For example, by immersing the glass substrate 210 in a salt bath (molten potassium nitrate) at 400 to 500° C. for a predetermined time, alkali metal ions (sodium ions) having a small ionic radius present in the surface layer of the glass substrate 210 can be induced to be replaced with an alkali metal ion (potassium ion) having a relatively large ionic radius. Accordingly, the compressive stress layer 220 is formed on the surface of the glass substrate 210 . The compressive stress layer 220 refers to an outer surface layer of the glass substrate 210 formed by intrusion of relatively large ions into the surface of the glass substrate 210 by ion exchange. As the compressive stress layer 220 is formed, the strength of the glass substrate 210 vulnerable to tensile stress may be increased. The strength of the glass substrate 210 may be further improved as the depth of the compressive stress layer 220 (Depth Of Layer, hereinafter referred to as 'DOL') (D) is deeper.

Tempered glass 201 according to another embodiment of the present invention is strengthened by a chemical strengthening method rather than a physical strengthening method, so that it is possible to strengthen the thin glass substrate 210, and it is possible to reduce the manufacturing cost and manufacturing time, Productivity and yield can be improved. In addition, it has the advantage of being able to strengthen the glass substrate 210 without additional deformation or physical processing.

Referring to FIG. 18 , a polishing process is performed on one surface of the curved portion BA of the tempered glass substrate 210 . The polishing process may be performed using a known apparatus and method. Hereinafter, a case in which the polishing process is performed on the upper surface of the curved portion BA will be described as an example. A portion of the upper surface of the curved portion BA is removed by the polishing process. In this case, the thickness of the curved portion BA is gradually reduced as it moves away from the flat portion FA by the polishing process. When viewed in cross-section, the upper surface of the curved portion BA may have an oblique shape. Accordingly, an angle between one surface of the flat portion FA and one surface of the adjacent curved portion BA is gentle.

Referring to FIG. 19 , when the upper surface of the curved portion BA is removed by the polishing process, a difference in DOL(D) occurs between the upper surface to which the polishing process is performed and the lower surface to which the polishing process is not performed. As the compressive stress formed on the upper surface of the curved portion BA is reduced compared to the compressive stress formed on the lower surface of the curved portion BA, the curved portion BA is bent upward in response to the difference in compressive stress. In this case, as the polishing process is locally performed on the curved portion BA, the thicknesses t2 and t3 of the curved portion BA are reduced compared to the thickness t1 of the flat portion FA. In addition, the thicknesses t2 and t3 of the curved portion BA may vary according to positions.

The curved portion BA of the tempered glass 201 according to another embodiment of the present invention may be formed by performing a polishing process with high precision. The method for manufacturing the tempered glass 201 according to another embodiment of the present invention may provide the tempered glass 201 having the curved portion BA having improved flatness and smoothness by using a polishing process.

Tempered glass 201 according to another embodiment of the present invention, by reducing the step 30 that may occur at the boundary between the flat portion FA and the curved portion BA, the step 30 is visible from the outside problems can be avoided. In addition, it is possible to prevent a problem of deterioration of visibility that may occur due to the stacking of foreign substances on the step 30 portion.

An example of the structure of the curved portion BA on which the polishing process is performed will be described with reference to FIG. 20 . 20 is an enlarged view of the AR′ region in FIG. 19 .

As the polishing process is performed on the upper surface of the curved portion BA, the thickness of the compressive stress layer 220 formed on the upper surface of the curved portion BA may be reduced. In this case, the thickness of the curved portion BA may be gradually reduced as the distance from the flat portion FA is increased (FIG. 20(a)). As the polishing process is performed on the upper surface of the curved portion BA, the compressive stress layer 220 formed in a portion of the upper surface may be removed. That is, the compressive stress layer 220 may remain in only a portion of the curved portion BA adjacent to the flat portion FA. As an example, the thickness of the curved portion BA of the region BA1 in which the compressive stress layer 220 remains is gradually reduced as the distance from the flat portion FA increases, and the region BA2 in which the compressive stress layer 220 does not remain. ), the thickness of the curved portion BA may be constant (FIG. 20(b)). As the polishing process is performed on the upper surface of the curved portion BA, a portion of the curved portion BA may be removed to the glass substrate 210 beyond the compressive stress layer 220 (FIG. 20(c)). ). The thickness removal amount of the curved portion BA may be adjusted to correspond to a target bending degree according to a designer's intention. However, the thickness removal amount of the curved portion BA is preferably adjusted appropriately so as to prevent a decrease in strength caused by the complete removal of the compressive stress layer 220 formed on the upper surface of the curved portion BA.

<Third embodiment>

Hereinafter, a tempered glass and a manufacturing method thereof according to a third embodiment of the present invention will be described with reference to FIGS. 21 to 29 .

21 and 22 are views schematically showing a tempered glass according to a third embodiment of the present invention. 21 and 22 , the tempered glass 301 according to the third embodiment of the present invention includes a flat portion FA and at least one curved portion BA. The curved portion BA refers to a bent area extending from the edge of the flat portion FA. When there are a plurality of curved portions BA, the curved portions BA may extend in different directions from the flat portion FA and be bent. In this case, an edge groove EDH may be further formed between the adjacent curved portions BA. The edge groove EDH includes a first side S1 and a second side S2 that meet at a point, the first side S1 and the second side S2 may be in contact with each other, and a preset angle ( θ) may have.

The curved portion BA has a thinner thickness than the flat portion FA. At the boundary between the flat portion FA and the curved portion BA, a step 30 may be formed by the thickness difference t1 and t2 between the flat portion FA and the curved portion BA (FIG. 22(a)). )). Alternatively, the flat portion FA may have a first thickness t1 , and the curved portion BA may have a thickness different from that of the flat portion FA, but may have different thicknesses t2 and t3 according to positions. For example, the thicknesses t2 and t3 of the curved portion BA may gradually change as the distance from the flat portion FA increases ( FIG. 22 ( b ) ).

Hereinafter, a method for manufacturing a tempered glass according to a third embodiment of the present invention will be described with reference to FIGS. 23 to 29 .

23 is a flowchart for explaining a method of manufacturing a tempered glass according to an embodiment of the present invention.

Referring to FIG. 23 , in the method of manufacturing a tempered glass 301 according to an embodiment of the present invention, a step (S310) of preparing a glass substrate in which a flat portion FA and a curved portion BA are defined (S310), adjacent curved surfaces A step of performing a chamfering process in the area where the portions BA overlap (S320), a step of forming a stress layer on the surface of the glass substrate by strengthening the glass substrate (S330), and a portion of the surface of the curved portion BA Including a step (S340) of performing an etching process or a polishing process in the region.

In order to manufacture the tempered glass 301 according to an embodiment of the present invention, a glass substrate in which a flat portion FA and a curved portion BA are defined is provided ( S310 ). A plurality of curved portions BA are defined in the glass substrate. The plurality of curved portions BA are positioned outside the flat portion FA. Each of the plurality of curved portions BA may be bent in different directions from the flat portion FA (refer to FIGS. 2, 8, and 16 ).

Subsequently, a chamfering process is performed in the area where the adjacent curved portions BA overlap ( S320 ). The chamfering process will be described later.

Next, a process of forming a stress layer on the surface of the glass substrate by strengthening the glass substrate is performed (S330). The strengthening process is performed according to a chemical strengthening method. The chemical strengthening method is a method of forming a stress layer on the glass surface layer through the substitution of ions (see FIGS. 3, 9 and 17 ).

Subsequently, an etching process or a polishing process is performed on at least a portion of the surface of the curved portion BA ( S340 ). When a portion of the surface of the curved portion BA is removed by the etching process or the polishing process, a difference in DOL occurs between the surface on which the etching process or the polishing process is performed and the surface on which the etching process or the polishing process is not performed. Due to the difference in compressive stress generated on the surface of the curved portion BA, the curved portion BA is bent in a specific direction (see FIGS. 4 to 6 , 10 to 12 , 18 and 19 ).

24 is a flowchart for explaining a method of manufacturing a tempered glass according to another embodiment of the present invention.

Referring to Figure 24, the manufacturing method of the tempered glass 301 according to an embodiment of the present invention, the step of preparing a glass substrate in which the flat portion FA and the curved portion BA are defined (S410), the glass substrate A step of forming a stress layer on the surface of the glass substrate by strengthening treatment (S420), a step of performing a chamfering process in the area where the adjacent curved portions BA overlap (S430), and a portion of the surface of the curved portion BA Including an etching process or a polishing process in the region (S440).

In order to manufacture the tempered glass 301 according to an embodiment of the present invention, a glass substrate having a flat portion FA and a curved portion BA defined is provided ( S410 ). A plurality of curved portions BA are defined in the glass substrate. The plurality of curved portions BA are positioned outside the flat portion FA. Each of the plurality of curved portions BA may be bent in different directions from the flat portion FA (refer to FIGS. 2, 8, and 16 ).

Next, a process of forming a stress layer on the surface of the glass substrate by strengthening the glass substrate is performed (S420). The strengthening process is performed according to a chemical strengthening method. The chemical strengthening method is a method of forming a stress layer on the glass surface layer through the substitution of ions (see FIGS. 3, 9 and 17 ).

Subsequently, a chamfering process is performed in the area where the adjacent curved portions BA overlap ( S430 ). The chamfering process will be described later.

Subsequently, an etching process or a polishing process is performed on at least a portion of the surface of the curved portion BA ( S440 ). When a portion of the surface of the curved portion BA is removed by the etching process or the polishing process, a difference in DOL occurs between the surface on which the etching process or the polishing process is performed and the surface on which the etching process or the polishing process is not performed. Due to the difference in compressive stress generated on the surface of the curved portion BA, the curved portion BA is bent in a specific direction (see FIGS. 4 to 6 , 10 to 12 , 18 and 19 ).

25 is a flowchart for explaining a method of manufacturing a tempered glass according to another embodiment of the present invention.

Referring to Figure 25, the manufacturing method of the tempered glass 301 according to another embodiment of the present invention, the step of preparing a glass substrate in which the flat portion FA and the curved portion BA are defined (S410), glass Forming a stress layer on the surface of the glass substrate by strengthening the substrate (S420), performing a chamfering process in the area where the adjacent curved portions BA overlap (S430), a portion of the surface of the curved portion BA Including a step (S440) of performing an etching process or a polishing process in the region, and further comprising a step (S450) of secondary strengthening treatment of the glass substrate.

When the chamfering process is performed after the process of strengthening the glass substrate, an additional process of secondary strengthening the glass substrate may be performed (S450).

A compressive stress layer is formed on the surface of the glass substrate by primary strengthening treatment. At this time, when a partial region of the curved portion BA is chamfered, the compressive stress layer in the chamfered region is removed. In other words, the end of the glass substrate exposed to the outside by the chamfering process remains in a state in which the compressive stress layer is not formed. The end of the glass substrate exposed to the outside has a lower strength than other regions of the glass substrate that have been strengthened, and is easily damaged from external impact. In order to solve this problem, a secondary strengthening treatment process may be performed on the glass substrate on which the chamfering process has been performed. At this time, the thickness of the compressive stress layer formed at the end of the glass substrate and the compressive stress layer formed in other regions may be different. If necessary, it may be preferable to perform the secondary strengthening treatment process only on the end of the glass substrate exposed to the outside. Accordingly, another embodiment of the present invention may provide the tempered glass 301 in which the strength is not lowered even after the chamfering process.

The chamfering process ( S320 and S430 ) will be described with reference to FIGS. 26 to 29 . 26 and 27 are views for explaining the positions of the flat portion and the curved portion defined in the tempered glass according to the third embodiment of the present invention. 28 and 29 are views for explaining a chamfering process performed on the tempered glass according to the third embodiment of the present invention.

The tempered glass 301 according to the third embodiment of the present invention may have n (n is a positive integer equal to or greater than 3) number of sides when viewed in a plan view. For example, referring to FIG. 26 , the tempered glass 301 may have three sides. The tempered glass 301 includes a flat portion FA, a first curved surface portion BA_1 positioned on one side of the outer side of the flat portion FA, and a second curved surface located on the other outer side of the flat portion FA. It may include part BA_2. The first curved portion BA_1 and the second curved portion BA_2 may be disposed adjacent to each other (FIG. 26(a)). The tempered glass 301 includes a flat portion FA, a first curved portion BA_1 positioned on one side of the outer side of the flat portion FA, and a second curved portion located on the other side of the flat portion FA. (BA_2) and a third curved portion BA_3 positioned in another side direction outside the flat portion FA may be included. At least one of the first curved portion BA_1 , the second curved portion BA_2 , and the third curved portion BA_3 may be disposed adjacent to the other ( FIG. 26B ).

As another example, referring to FIG. 27 , the tempered glass 301 may have four sides. The tempered glass 301 includes a flat portion FA, a first curved surface portion BA_1 positioned on one side of the outer side of the flat portion FA, and a second curved surface located on the other outer side of the flat portion FA. It may include part BA_2. The first curved portion BA_1 and the second curved portion BA_2 may be disposed adjacent to each other ( FIG. 27A ). The tempered glass 301 includes a flat portion FA, a first curved portion BA_1 positioned on one side of the outer side of the flat portion FA, and a second curved portion located on the other side of the flat portion FA. (BA_2) and a third curved portion BA_3 positioned in another side direction outside the flat portion FA may be included. At least one of the first curved portion BA_1 , the second curved portion BA_2 , and the third curved portion BA_3 may be disposed adjacent to the other ( FIG. 27B ). The tempered glass 301 includes a flat portion FA, a first curved portion BA_1 positioned on one side of the outer side of the flat portion FA, and a second curved portion located on the other side of the flat portion FA. (BA_2), a third curved portion BA_3 positioned on the other side of the planar portion FA, and a fourth curved portion BA_4 positioned on the other side of the flat portion FA. You may. At least one of the first curved part BA_1 , the second curved part BA_2 , the third curved part BA_3 , and the fourth curved part BA_4 may be disposed adjacent to the other (see FIG. 27 ). (c)).

As described above, when a plurality of curved portions BA are defined on the glass substrate, the curved portions BA may be disposed adjacent to each other. In this case, an area OA in which the adjacent curved portions BA meet each other (or an edge area between the adjacent curved portions BA) OA is defined as an overlapping area OA of the curved portions BA. The chamfering process is performed on the overlapping area OA of the adjacent curved portions BA.

When the adjacent curved portions BA are bent while the overlapping area OA remains, the curved portions BA are affected by the overlapping area OA and are not bent along the intended bending direction and the intended bending curvature. it may not be In addition, process defects such as cracks or wrinkles may occur in the overlapping area OA when the curved portions BA are bent. Therefore, an additional process for removing the overlapping area is required.

Referring to FIG. 28 , the glass substrate 310 before the chamfering process includes a flat portion FA, a first curved portion BA_1 , a second curved portion BA_2 , and adjacent first curved portions BA_1 and second The overlapping area OA of the curved portion BA_2 may be included. The overlapping area OA is removed by a chamfering process. The chamfering process may be performed using a variety of known methods, for example, known machining, etching, and the like. By the chamfering process, edge grooves EDH are formed in the glass substrate 310 .

Referring to FIG. 29 , the edge groove EDH includes a first side S1 and a second side S2 that meet at a point. The first side S1 and the second side S2 have a predetermined first angle θ1 . The first angle θ1 may be set in consideration of the positions of the first side S1 and the second side S2 after the glass substrate 310 is bent by an etching process or a polishing process. After the curved portions BA are bent, the first side S1 and the second side S2 may contact each other and may have a preset second angle θ2 . The designer appropriately sets the first angle θ1 in consideration of the degree of bending in order to set the positions of the first side S1 and the second side S2 after the curved portions BA are bent to desired positions. can be set. The drawing illustrates a state in which the second angle θ2 varies according to the first angle θ1 when the degree of bending is the same.

A third embodiment of the present invention is characterized in that the overlapping area is eliminated. Accordingly, according to the third embodiment of the present invention, a process defect in which the curved portions BA are bent to have a bending direction and curvature different from the designer's intention by the overlapping area OA may be prevented. That is, in the third embodiment of the present invention, although the curved portions BA have to be bent along different bending directions, they are affected by the overlapping area OA connected to all of the neighboring curved portions BA. Defects that are bent in a normal shape can be prevented.

<Fourth embodiment>

The tempered glass 1, 201, and 301 according to the first, second, and third embodiments of the present invention can be used in various fields. 30 is a view for explaining an application field of the tempered glass according to the first, second, and third embodiments of the present invention.

For example, referring to FIG. 30A , the tempered glass 1 , 201 , and 301 according to the present invention may be a cover glass CW of a display device having a curved surface. The cover glass CW functions as a substrate for protecting elements inside the display device. The display device may include a display panel (DP) having display elements and driving elements for image realization, and a touch screen panel (TSP) sensing a movement of a user's hand and/or a conductor. In this case, the cover glass CW disposed on the touch screen panel TSP needs to be thin in order to prevent a decrease in touch sensing sensitivity, and a thin film type tempered glass strengthened not to be easily broken by an external impact needs to be used. In addition, it is necessary to use a cover glass (CW) including a curved portion in response to variously changing different types of display devices. Accordingly, the tempered glass 1 , 201 , and 301 according to the present invention may perform all of the above-described functions, and thus may be suitable as a cover glass CW of a display device.

As another example, referring to FIG. 30B , the tempered glass 1 , 201 , and 301 according to the present invention may be a protective film PF that protects a cover glass of a display device. Tempered glass (hereinafter, referred to as a “tempered glass film”) is used as a protective film PF for protecting the cover glass CW of the display device DD. The tempered glass film PF needs to secure the mechanical strength required to protect the cover glass CW provided on the outermost side of the display device DD. In addition, in order to improve aesthetics, it is necessary to respond to various release products, and it is necessary to be thin in order to prevent an increase in thickness. Accordingly, the tempered glass 1 , 201 , and 301 according to the present invention can satisfy these requirements, and a tempered glass film ( PF) may be suitable.

Those skilled in the art through the above description will be able to make various changes and modifications without departing from the technical spirit of the present invention. Accordingly, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

1, 201, 301: tempered glass 10, 210, 310: glass substrate
FA: flat part BA: curved part
20, 220: compressive stress layer 30: step
240: filling layer OA: overlapping area
EDH: Corner groove PF: Tempered glass film

Claims (11)

In the tempered glass formed by wrapping the entire compressive stress layer on the surface of the glass substrate,
flat part; and
At least one curved portion extending from the edge of the flat portion; including,
In the glass substrate on which the compressive stress layer is formed, the compressive stress layer on the upper surface or lower surface of the curved part is removed through an etching process in a state in which the mask has an opening to expose the upper surface or the lower surface of the curved part, A step is formed at a boundary between the flat portion and the curved portion, and the curved portion is bent due to a compressive stress difference while the thickness of the curved portion is formed thinner than the thickness of the flat portion,
Tempered glass in which a corner groove is formed through a chamfering process in the overlapping region between the adjacent curved portions. delete delete The method of claim 1,
The thickness of at least one of the curved portions,
Tempered glass that gradually changes as it goes away from the flat portion. delete The method of claim 1,
The corner groove includes a first side and a second side that meet at a point,
The first side and the second side are,
In contact with each other, or tempered glass having a preset angle. A first step of providing a flat portion and a glass substrate in which a plurality of curved portions located outside the flat portion are defined;
a second step of performing a chamfering process on a region where the adjacent curved portions overlap;
a third step of allowing a compressive stress layer to be entirely wrapped around the surface of the glass substrate; and
The compressive stress layer on the upper surface or lower surface of the curved part is removed through an etching process in a state in which the glass substrate on which the compressive stress layer is formed is wrapped in a mask having an opening so that the upper surface or lower surface of the curved part is exposed, and the A step is formed at a boundary between the flat portion and the curved portion, and the thickness of the curved portion comprises a fourth step of being thinner than the thickness of the flat portion,
The method of manufacturing a tempered glass in which the curved portion is bent due to a compressive stress difference in an etching process or a polishing process. A first step of providing a flat portion and a glass substrate in which a plurality of curved portions located outside the flat portion are defined;
a second step of allowing the compressive stress layer to be entirely wrapped around the surface of the glass substrate;
a third step of performing a chamfering process on a region where the adjacent curved portions overlap; and
The compressive stress layer on the upper surface or lower surface of the curved part is removed through an etching process in a state in which the glass substrate on which the compressive stress layer is formed is wrapped in a mask having an opening so that the upper surface or lower surface of the curved part is exposed, and the A step is formed at a boundary between the flat portion and the curved portion, and the thickness of the curved portion comprises a fourth step of being thinner than the thickness of the flat portion,
The method of manufacturing a tempered glass in which the curved portion is bent due to a compressive stress difference in an etching process or a polishing process. 9. The method according to any one of claims 7 to 8,
Tempered glass manufacturing method further comprising a corner groove formed in a region where the curved portions overlap by the chamfering process. 10. The method of claim 9,
The corner groove includes a first side and a second side that meet at a point,
The first side and the second side are the tempered glass manufacturing method having a preset angle. 9. The method of claim 8,
Tempered glass manufacturing method further comprising a fifth step of secondary strengthening the glass substrate.

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