KR20170033210A - Curved Tempered Glass And Method For Manufacturing The Same - Google Patents

Abstract

The present invention relates to a tempered glass, comprising: a plane part; and a curved part extended from the plane part to be bent. The average thickness of the curved part is thinner than the thickness of the plane part. The present invention controls curvature and variously designs the section shape of the curved part, thereby improving the convenience of design.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tempered glass having a curved surface portion,

The present invention relates to a tempered glass having a curved portion and a manufacturing method thereof.

In recent years, tempered glass whose surface has been reinforced to increase the mechanical strength of fragile glass has been spreading, and its application field has also been diversified. For example, due to the development of portable information processing devices, the demand for various display devices is increasing rapidly. The display device includes a protective cover for protecting internal elements of the display device, and glass can be used as the material of the protective cover. When glass is used as the protective cover, it has the advantage of securing weather resistance, scratch resistance and high transmittance, but it is exposed to the outside, which can be easily broken by an impact due to external factors. In order to solve such disadvantages, studies for securing the mechanical strength of glass have been actively conducted.

As a method for strengthening glass, a physical strengthening method is known. The physical strengthening method is a method in which the glass is heated at a high temperature for a certain time and then the surface of the glass is quenched by wind cooling or the like to cause a compressive stress on the surface of the glass and a tensile stress to be generated inside.

However, the physical strengthening method using the temperature difference between the inside and the outside has a limitation 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 because the temperature difference between the surface and the inside is hard to occur. The display device may include a touch screen panel capable of recognizing a user's touch and / or gesture, thereby sensing a motion of a user's hand or a conductive body. The glass for protecting the display device is required to be formed as a thin film in order to increase the sensitivity of the touch sensing. Thus, there is a limit to using physical strengthening methods to form thin tempered glass.

On the other hand, as glass is applied in various fields, a glass having a curved portion corresponding to various needs of the user is spreading. For example, as a curved surface display device is provided, it is required to manufacture a glass having a curved surface portion as a protective cover corresponding to a curved surface display device.

Conventional techniques for manufacturing a glass including a curved portion include a press 55 that heats the glass to a predetermined temperature or higher and presses the glass using a conventional machining method using a lathe and an automatic lathe (CNC), a mold corresponding to a glass shape including a curved portion, A molding method, and a slumping molding method using gravity and a mold at a high temperature. However, the glass provided by such a method has problems of poor quality, low productivity and yield. Also, there is a question of how the tempered glass can be processed.

Accordingly, there is a need to develop a tempered glass manufacturing method capable of raising the mechanical strength of a thin glass to be strengthened, and also capable of processing a curved portion.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a tempered glass having a curved portion by chemically strengthening a thin glass and performing a removal process on a part thereof. It is another object of the present invention to provide a tempered glass having reduced steps that can be formed at the boundary between a flat portion and a curved portion. It is also an object of the present invention to provide tempered glass having various cross-sectional shapes.

In order to achieve the above or other objects, the present invention relates to a tempered glass having a flat portion and a curved portion bent from the flat portion, wherein a thickness of at least one point of the curved portion is thinner than a thickness of the flat portion.

The tempered glass according to the present invention is strengthened by the chemical strengthening method, so that the tempering treatment can be performed on the thin glass base material, the manufacturing cost and the manufacturing time can be reduced, and the productivity and the yield can be improved. It also has the advantage that it can be strengthened without further deformation or physical processing of the glass substrate.

The present invention can improve the productivity and yield by forming the curved surface portion through the etching process, unlike the processing methods used to form the curved portion in the past, to prevent the deterioration of the quality of the processed glass, So that the time can be shortened. In addition, according to the method of manufacturing tempered glass according to an embodiment of the present invention, since the designer can process the shape of the final product by controlling the process conditions, it is possible to make various design changes compared to the conventional method using the mold And the design change is relatively easy.

The present invention can prevent a step from appearing from the outside by reducing a step that can be formed along the boundary between the plane portion and the curved portion during the process. Further, the present invention can prevent the visibility degradation problem that may occur due to the deposition of foreign matter or the like on the stepped portion.

According to the present invention, it is possible to provide a tempered glass having various curvilinear cross-sectional shapes, corresponding curvature, and improved aesthetics and design convenience.

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 tempered glass according to an embodiment of the present invention.
FIG. 7 is an enlarged view of the AR area in FIG.
8 to 12 are cross-sectional views illustrating a process for manufacturing 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 illustrating a tempered glass according to an embodiment of the present invention and a process for manufacturing the same.
15 is a cross-sectional view illustrating a tempered glass according to another embodiment of the present invention and a process for manufacturing the same.
16 to 19 are sectional views illustrating a process for manufacturing tempered glass according to another embodiment of the present invention.
20 is an enlarged view of the region AR 'in FIG.
21 is a plan view schematically showing a tempered glass according to a third embodiment of the present invention.
FIGS. 22 to 25 are views for explaining the cross-sectional shape of the tempered glass according to the third embodiment of the present invention, which is obtained by cutting FIG. 21 into I-I '.
26 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, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are used to designate identical or similar elements, and redundant description thereof will be omitted. The suffix "part" for the constituent elements used in the following description is to be given or mixed with consideration only for ease of specification, and does not have a meaning or role that distinguishes itself. In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be blurred. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. , ≪ / RTI > equivalents, and alternatives.

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

The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

≪ Embodiment 1 >

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. FIG.

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 planar portion FA and a curved portion BA. The plane portion FA means a region having a planar shape in the tempered glass 1 according to the present invention. The curved surface portion BA means a region where the tempered glass 1 according to the present invention is bent to have a curved shape. The curved surface portion BA extends from at least one side of the flat surface portion FA. The flat surface portion FA has a first thickness t1 and the curved surface portion BA has a second thickness t2. A step 30 is formed at the boundary between the flat surface portion FA and the curved surface portion BA by the thickness difference between the flat surface portion FA and the curved surface portion BA.

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

Referring to Fig. 2, a glass substrate 10 for a tempering treatment is provided. The glass substrate 10 has a flat surface portion FA and a curved surface portion BA extending from at least one side of the flat surface portion FA. The plane portion FA means a region having a planar shape after the final process. The curved portion BA refers to a region having a curved shape bent after the final process.

Referring to FIG. 3, a tempering process for reinforcing the glass substrate 10 on which the plane portion FA and the curved surface portion BA are defined proceeds. The tempering process proceeds according to the chemical strengthening method. The chemical strengthening method is a method of forming a stress layer on the glass surface layer through substitution of ions. The stress layer may be a compressive stress layer (20). The driving force for ion substitution can be influenced by the diffusion coefficient of individual ions due to 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 period of time, alkali metal ions (sodium ions) having a small ionic radius existing in the surface layer of the glass substrate 10, Can be induced to be substituted with an alkali metal ion (potassium ion) having a relatively large ionic radius. Thus, a compressive stress layer 20 is formed on the surface of the glass substrate 10. The compressive stress layer 20 refers to the outer surface layer of the glass substrate 10 formed by ion exchange with relatively large ions entering the surface of the glass substrate 10. As the compressive stress layer 20 is formed, the strength of the glass substrate 10 which is susceptible to tensile stress can be increased. The strength of the glass substrate 10 can be further improved as the depth of the compressive stress layer 20 (hereinafter referred to as DOL) is deeper.

The tempered glass 1 according to the embodiment of the present invention is reinforced by a chemical strengthening method rather than a physical strengthening method, so that it is possible to strengthen the thin glass substrate 10, reduce the manufacturing cost and the manufacturing time, Productivity and yield can be improved. It also has the advantage that it can be strengthened without additional deformation or physical processing of the glass substrate 10.

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

Referring to FIG. 5, an etching process is performed to apply the etching solution 60 to the surface of the glass substrate 10 provided with the mask 50. The etching process may include all known processes capable of removing the surface of the glass substrate 10. It is preferable that the etching liquid 60 is applied in a direction perpendicular to the surface exposed by the opening OR. A part of the thickness of the curved portion BA exposed to the outside by the opening OR is removed through the etching process.

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 on which the etching process is performed and the upper surface on 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, the curved portion BA bends downward corresponding to the compressive stress difference. At this time, the thickness t2 of the curved surface portion BA is reduced as compared with the thickness t1 of the flat surface portion FA as the etching process is performed exclusively on the curved surface portion BA. Therefore, a step 30 is generated at the boundary between the curved surface portion BA and the flat surface portion FA.

Unlike the processing methods used to form the conventional curved surface portion BA, the present invention can improve the productivity and yield by forming the curved surface portion BA through the etching process, and prevent deterioration of the quality of the processed glass And has the effect of shortening the manufacturing cost and the manufacturing time. In addition, the method of manufacturing a tempered glass according to an embodiment of the present invention allows a designer to adjust process conditions such as a tempering process time and a depth of a DOL, a kind and amount of an etchant, and an etching process time, Can be processed. Accordingly, it is possible to perform various design changes in comparison with a processing method using a conventional mold or the like, and it is advantageous that the design change is relatively easy.

For example, the method of manufacturing the tempered glass 1 according to an embodiment of the present invention may vary the degree of bending of the curved portion BA with different etching amounts. Table 1 shows the results of the experiment when the length L of the curved surface portion BA in the glass of 0.1T thickness t was 10mm as the reference REF (see Fig. 3) And the bending degree of the curved surface portion BA can be adjusted. The etching amount in the table means the thickness of the lower surface of the curved portion (BA) removed through the etching process.

0.1 T Glass DOL (D) (占 퐉) Etching amount (탆) Curved surface portion 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 surface portion BA may be varied by changing the DOL (D). Table 2 shows DOL (D) in the state where the other conditions are constant, with reference to the reference REF when the length L of the curved surface portion BA is 10 mm in the glass of 0.1T thickness (t) It is possible to adjust the degree of bending of the curved portion BA by controlling only the curvature of the curved portion BA.

0.1 T Glass DOL (D) (占 퐉) Etching amount (탆) Curved surface portion 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, the method of manufacturing the tempered glass 1 according to an embodiment of the present invention may vary the degree of bending of the curved portion BA by varying the etching amount and the DOL (D). Table 3 shows the relationship between the etching amount and / or the etching amount in a state where other conditions are constant, with reference to the reference REF when the length L of the curved surface portion BA is 10 mm in the glass of 0.1T thickness (t) Or DOL (D) to control the degree of bending of the curved portion BA.

0.1 T Glass DOL (D) (占 퐉) Etching amount (탆) Curved surface portion 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

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

As shown in FIG. 7 and the above-described 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 can be reduced (Fig. 7 (a)), the compressive stress layer 20 can be removed (Fig. 7 (b)) and over-stressed beyond the compressive stress layer 20 ). The etching amount can be adjusted to correspond to the degree of bending which is the target, according to the intention of the designer. However, it is preferable that the etching amount is appropriately adjusted so as to prevent the strength reduction 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. FIG. 8 to 12 are cross-sectional views illustrating a process for manufacturing tempered glass according to another embodiment of the present invention.

Referring to Fig. 8, a glass substrate 10 for a tempering treatment is provided. The glass substrate 10 has a flat surface portion FA and a curved surface portion BA extending from at least one side of the flat surface portion FA. The plane portion FA means a region having a planar shape after the final process. The curved portion BA refers to a region having a curved shape bent after the final process.

Referring to FIG. 9, a tempering process for strengthening the glass substrate 10 on which the plane portion FA and the curved portion BA are defined proceeds. The tempering process proceeds according to the chemical strengthening method. The chemical strengthening method is a method of forming a stress layer on the glass surface layer through substitution of ions. The stress layer may be a compressive stress layer (20). The driving force for ion substitution can be influenced by the diffusion coefficient of individual ions due to 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 period of time, alkali metal ions (sodium ions) having a small ionic radius existing in the surface layer of the glass substrate 10, Can be induced to be substituted with an alkali metal ion (potassium ion) having a relatively large ionic radius. Thus, a compressive stress layer 20 is formed on the surface of the glass substrate 10. The compressive stress layer 20 refers to the outer surface layer of the glass substrate 10 formed by ion exchange with relatively large ions entering the surface of the glass substrate 10. As the compressive stress layer 20 is formed, the strength of the glass substrate 10 which is susceptible to tensile stress can be increased. The strength of the glass substrate 10 can be further improved as the DOL (D) of the compressive stress layer 20 is deeper.

The tempered glass 1 according to another embodiment of the present invention is reinforced by a chemical strengthening method instead of a physical strengthening method to enable strengthening treatment in the thin glass base 10 and to reduce manufacturing cost and manufacturing time, Productivity and yield can be improved. It also has the advantage that it can be strengthened without additional deformation or physical processing of the glass substrate 10.

Referring to Fig. 10, a polishing pad 53 and a press 55 for providing a load to the polishing pad 53 are provided on the reinforced glass substrate 10. The polishing pad 53 is disposed on either the upper surface or the lower surface of the curved surface portion BA. The surface of the curved surface portion BA on which the polishing pad 53 is disposed can be determined according to the bending direction intended by the designer. In other words, depending on the position where the polishing pad 53 is disposed, the bending direction of the curved surface portion BA can be determined. For example, the designer may place the polishing pad 53 on the upper surface of the curved portion BA to bend the curved portion BA upward. Hereinafter, the case where the polishing pad 53 is disposed on the upper surface of the curved surface portion in order to bend the curved surface 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 reinforced glass substrate 10. The upper surface of the curved portion is in contact with the polishing pad 53. The upper surface of the curved portion is provided with a polishing load from the press 55 through the polishing pad 53. [ The polishing pad 53 can be operated repeatedly in a specific direction as shown. A part of the upper surface of the curved surface portion BA is removed by the repetitive operation of the polishing pad 53. [ In order to continuously carry out the polishing process, it is possible to selectively supply the polishing liquid and the cleaning liquid during operation of the polishing pad 53, thereby increasing the process efficiency and yield. The processing conditions such as the polishing load, the polishing rate, and the polishing time can be appropriately selected depending on the strength of the glass base material and the like. The shape and structure of the polishing pad 53, the polishing process method, and the like can be well known techniques.

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 where the polishing process is performed and the lower surface where 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, the curved portion BA bends upward in correspondence to the compressive stress difference. At this time, the thickness t2 of the curved surface portion BA is reduced as compared with the thickness t1 of the flat surface portion FA, as the polishing process is performed only on the curved surface portion BA. Therefore, a step 30 is generated at the boundary between the curved surface portion BA and the flat surface portion FA.

The curved surface portion BA of the tempered glass according to the present invention can be formed by carrying out the polishing process with high accuracy. The tempered glass manufacturing method according to another embodiment of the present invention can provide a tempered glass having a curved surface portion BA having improved flatness and smoothness by using a polishing process.

≪ Embodiment 2 >

The second embodiment of the present invention is characterized by providing tempered glass 201 in which the step 30 formed at the boundary between the plane portion FA and the curved portion BA is reduced, unlike the first embodiment. The step 30 formed at the boundary between the plane part FA and the curved part BA can be visually recognized from the outside and can be a factor for lowering the esthetics of the tempered glass 201. [ Foreign bodies and the like can be stacked on the step 30 formed at the boundary between the flat surface part FA and the curved surface part BA during the manufacturing process and / It is possible to reduce the visibility of the light incident on the light guide plate. In order to solve such a problem, a method of manufacturing tempered glass 201 and tempered glass 201 in which steps 30 that can be formed at the boundary between the plane portion FA and the curved portion BA are 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 planar portion FA and a curved portion BA. The plane portion FA means a region having a planar shape in the tempered glass 201 according to the present invention. The curved surface portion BA means a region where the tempered glass 201 according to the present invention is bent to have a curved shape. The curved surface portion BA is located at least in one direction extending from the plane portion FA. The inclination between one surface of the flat surface portion FA and one surface of the curved surface portion BA adjacent thereto is gentle. To this end, the curved surface portion BA has a thickness different from that of the flat surface portion FA. For example, the flat surface portion FA has a first thickness t1, the curved surface portion BA has a thickness different from that of the flat surface portion FA, but has different thicknesses t2 and t3 depending on the position have.

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

14, an embodiment of the present invention is a glass substrate 1 having a step 30 at the boundary between the tempered glass 1 according to the first embodiment, that is, the plane portion FA and the curved portion BA, The stepped portion 30 is reduced on the assumption that the stepped portion 210 is formed. The tempered glass 201 formed through the steps of FIG. 2 to FIG. 6 or FIG. 8 to FIG. 12 may be formed by performing an etching process or a polishing process on any one side of the curved surface portion BA to change the thickness of the curved surface portion BA, The thicknesses of the fins FA differ. That is, a part of the thickness of one side of the curved surface portion BA is removed so that the thickness t2 of the curved surface portion BA is reduced compared to the thickness t1 of the flat surface portion FA. As a result, a step 30 whose slope is urged is formed at the boundary between the curved surface portion BA and the flat surface portion FA.

An additional polishing process is performed on the stepped portion formed at the boundary between the plane portion FA and the curved portion BA. Additional polishing processes may be performed using known devices and methods. By the additional polishing process, one surface of the stepped glass substrate 210 is removed. The removed one surface may be a compressive stress layer 220. As a portion of the compressive stress layer 220 is removed, the degree of bending of the curved portion BA may vary. For convenience of explanation, an area where the additional polishing process proceeds in the curved surface portion BA will be defined as a first curved surface portion BA1. In other words, the curved surface portion BA is defined as a first curved surface portion BA1 adjacent to the plane portion FA and a second curved surface portion BA2 spaced apart from the plane portion FA, and the first curved surface portion BA1, Quot; refers to the area where the additional polishing process proceeds. In this case, the thickness of the curved surface portion BA is formed to be thinner than the thickness of the flat surface portion FA. The thickness of the first curved surface portion BA1 gradually decreases as the distance from the plane portion FA increases, The thickness of the portion BA2 is constant.

Since the additional polishing process performed on the first curved portion BA1 is for the purpose of removing the step 30, it may be sufficient to remove only the compressive stress layer 220 in the narrow region. It should therefore 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 that reduces the level difference 30 through the additional polishing process can prevent the level difference 30 from being visually recognized from the outside. In addition, it is possible to prevent a problem of visibility deterioration which may occur due to the deposition of foreign matter or the like on the stepped portion 30.

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

15, another embodiment of the present invention is a glass base material 1 in which a tempered glass 1 according to the first embodiment, that is, a step 30 is formed at the boundary between the plane portion FA and the curved portion BA, The stepped portion 30 is reduced on the assumption that the stepped portion 210 is formed. The tempered glass 201 formed through the steps of FIG. 2 to FIG. 6 or FIG. 8 to FIG. 12 may be formed by performing an etching process or a polishing process on any one side of the curved surface portion BA to change the thickness of the curved surface portion BA, The thicknesses of the fins FA differ. That is, a part of the thickness of one side of the curved surface portion BA is removed so that the thickness t2 of the curved surface portion BA is reduced compared to the thickness t1 of the flat surface portion FA. As a result, a step 30 whose slope is urged is formed at the boundary between the curved surface portion BA and the flat surface portion FA.

The process of forming the filling layer 240 on the curved surface portion BA of the glass substrate 210 proceeds in order to reduce the level difference 30. [ The filler layer 240 functions to fill the step 30 formed at the boundary between the curved surface portion BA of the glass substrate 210 and the planar portion FA. That is, the filler layer 240 is positioned to fill the step 30 formed along the boundary between the curved surface portion BA and the planar surface portion FA, so that the one surface of the planar surface portion FA and the curved surface portion BA adjacent thereto Have a gentle slope on one side.

The filling layer 240 may be formed on one side of the curved portion BA on which the step 30 is formed. In this case, the glass base material 210 and the filler layer 240 are laminated on the curved surface portion BA of the tempered glass 201 and the thicknesses t2 and t3 of the curved surface portion BA are And gradually decreases as the distance increases (Fig. 15 (a)). The filling layer 240 may be formed only on one side of the curved portion BA on which the step 30 is formed. That is, the curved surface portion BA may be defined as a first curved surface portion BA1 adjacent to the plane portion FA and a second curved portion BA2 spaced from the plane portion FA. In this case, the first curved surface portion BA1 refers to a region where the filler layer 240 is laminated on the glass substrate 210. In this case, the thickness of the curved surface portion BA of the tempered glass 201 is formed to be thinner than the thickness of the flat surface portion FA, and the thickness t2 of the first curved surface portion BA1 is away from the flat surface portion FA And the thickness t3 of the second curved surface 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 resin, an epoxy resin, and a urethane resin. 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 characteristics in order to prevent the visibility of the light passing through the glass substrate 210 and the filling layer 240 from being visually impaired by the user. In addition, it is preferable that the filling layer 240 is a material having the same level of transmittance and refractive index as 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 filler layer 240 can prevent the step 30 from being visible from the outside. In addition, it is possible to prevent a problem of visibility deterioration which may occur due to the deposition of foreign matter or the like on the stepped portion 30.

The filler layer 240 may function as a buffer layer formed on the curved surface portion BA to absorb 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 portion of the compressive stress layer 220 removed and have a lower strength than the peripheral region. In this situation, another embodiment of the present invention is characterized in that the curved surface portion BA is further provided with the filler layer 240, so that the tempered glass 201, which reduces deformation or cracking of the curved surface portion BA by external force externally provided, Can be provided.

Hereinafter, the tempered glass 201 and its manufacturing method according to still another embodiment of the present invention will be described with reference to Figs. 16 to 19. Fig. 16 to 19 are sectional views illustrating a process for manufacturing tempered glass according to another embodiment of the present invention.

Referring to Fig. 16, a glass substrate 210 for a tempering treatment is provided. The glass substrate 210 has a flat surface portion FA and a curved surface portion BA extending from at least one side of the flat surface portion FA. The plane portion FA means a region having a planar shape after the final process. The curved portion BA refers to a region having a curved shape bent after the final process.

Referring to FIG. 17, a tempering process for reinforcing the glass substrate 210 on which the plane portion FA and the curved surface portion BA are defined proceeds. The tempering process proceeds according to the chemical strengthening method. The chemical strengthening method is a method of forming a stress layer on the glass surface layer through substitution of ions. The stress layer may be a compressive stress layer (220). The driving force for ion substitution can be influenced by the diffusion coefficient of individual ions due to diffusion by concentration gradient. For example, by immersing the glass substrate 210 in a salt bath (molten potassium nitrate) at 400 to 500 占 폚 for a certain period of 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 substituted with an alkali metal ion (potassium ion) having a relatively large ionic radius. Accordingly, a compressive stress layer 220 is formed on the surface of the glass substrate 210. The compressive stress layer 220 refers to the outer surface layer of the glass substrate 210 formed by ion-exchange with relatively large ions entering the surface of the glass substrate 210. As the compressive stress layer 220 is formed, the strength of the glass substrate 210 that is susceptible to tensile stress can be increased. The strength of the glass substrate 210 can be further improved as the depth of the compressive stress layer 220 (hereinafter referred to as " DOL ") is deeper.

The tempered glass 201 according to another embodiment of the present invention is reinforced by the chemical strengthening method instead of the physical strengthening method so that the tempering treatment can be performed in the thin glass base material 210 and the manufacturing cost and the manufacturing time can be reduced, Productivity and yield can be improved. It also has the advantage that it can be strengthened without further deformation or physical processing of the glass substrate 210.

Referring to FIG. 18, a polishing process is performed on one surface of the curved surface portion BA of the reinforced glass substrate 210. The polishing process can be performed using known apparatuses and methods. Hereinafter, the polishing process proceeds on the upper surface of the curved portion BA as an example. A part of the upper surface of the curved surface portion BA is removed by the polishing process. At this time, the thickness of the curved surface portion BA gradually becomes thinner away from the plane portion FA by the polishing process. Viewed in cross-section, the upper surface of the curved portion BA may have an oblique shape. Accordingly, the angle formed between one surface of the flat surface portion FA and one surface of the curved surface portion BA adjacent thereto 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 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, the curved portion BA bends upward in correspondence to the compressive stress difference. At this time, the thickness t2, t3 of the curved surface portion BA is reduced as compared with the thickness t1 of the flat surface portion FA as the polishing process is performed exclusively for the curved surface portion BA. In addition, the thicknesses t2 and t3 of the curved surface portion BA may differ depending on the position.

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

The tempered glass 201 according to another embodiment of the present invention reduces the level difference 30 that may occur at the boundary between the plane portion FA and the curved surface portion BA so that the level difference 30 is visible from the outside Problems can be prevented. In addition, it is possible to prevent a problem of visibility deterioration which may occur due to the deposition of foreign matter or the like on the stepped portion 30.

20, an example of the structure of the curved surface portion BA on which the polishing process has been performed will be described. 20 is an enlarged view of the region AR 'in FIG.

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 can be reduced. At this time, the thickness of the curved surface portion BA can be gradually reduced as the distance from the plane portion FA (Fig. 20 (a)). As the polishing process is performed on the upper surface of the curved portion BA, the compressive stress layer 220 formed on a portion of the upper surface can be removed. That is, the compressive stress layer 220 may remain only in a portion of the curved surface portion BA adjacent to the plane portion FA. 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 plane portion FA is increased and the region of the compressive stress layer 220 remaining in the region BA2 (FIG. 20 (b)). As the polishing process is performed on the upper surface of the curved portion BA, a part of the curved portion BA may be removed to the region outside the compressive stress layer 220 beyond the compressive stress layer 220 (c). The thickness removal amount of the curved surface portion BA can be adjusted so as to correspond to the degree of bending that becomes the target according to the designer's intention. However, it is preferable that the thickness removal amount of the curved surface portion BA is appropriately adjusted so as to prevent the strength reduction caused by the complete removal of the compressive stress layer 220 formed on the upper surface of the curved surface portion BA.

≪ Third Embodiment >

Hereinafter, the tempered glass 301 according to the third embodiment of the present invention will be described with reference to Figs. 21 to 25. Fig.

21 is a plan view schematically showing a tempered glass according to a third embodiment of the present invention. Figs. 22 to 25 are views for explaining the cross-sectional shape of the tempered glass according to the third embodiment of the present invention, which is obtained by cutting Fig. 21 into I-I '.

Referring to FIG. 21, the tempered glass 301 according to the third embodiment of the present invention includes a flat surface portion FA and a curved surface portion BA. The plane portion FA means a region having a planar shape in the tempered glass 301 according to the present invention. The curved surface portion BA refers to a region where the tempered glass 301 according to the present invention is bent to have a curved shape. The curved surface portion BA extends from at least one side of the flat surface portion FA. The curved surface portion BA may be plural. The plurality of curved portions BA can be bent and extended in different directions from the plane portion FA, respectively.

The tempered glass 301 according to the present invention is shown as having four sides in plan view, but it is not limited thereto. For example, the tempered glass 301 according to the present invention may have a planar shape with n sides (where n is a positive integer of 3 or more) when viewed in plan view. In the drawing, two curved portions BA extending from one plane portion FA to one side and the other side are shown, but the present invention is not limited thereto. For example, when the tempered glass 301 has a planar shape having n sides, it may have 1 to n curved portions BA.

22 to 25, the tempered glass 301 according to the third embodiment of the present invention includes a planar portion FA and a curved portion BA. The curved surface portion BA may have various cross-sectional shapes. 22 to 25 are merely examples for illustrating the cross-sectional shape of the tempered glass 301 according to the present invention, and it should be noted that the present invention is not limited to the drawings. 22 to 25 illustrate a sectional shape of the curved surface portion BA deformed by the etching or polishing process and are arbitrarily shown before the curved surface portion BA is bent for convenience of explanation .

The curved surface portion BA may be bent and extended from the plane portion FA, and may be plural. And the average thickness of the curved surface portion BA is thinner than the thickness of the flat surface portion FA. Since at least one region of the curved surface portion BA is subjected to the etching process or the polishing process, the average thickness of the curved surface portion BA is thinner than the plane portion FA. Therefore, the thickness of at least one point of the curved surface portion BA is thinner than the thickness of the flat surface portion FA.

Referring to FIG. 22 (a), the tempered glass 301 may include a step formed along the boundary between the plane portion FA and the curved portion BA. The thickness of the curved surface portion BA may be constant.

Referring to FIG. 22 (b), the curved surface portion BA may have a different thickness depending on the position. The thickness of the curved portion BA may become thinner toward the end. The thickness of the curved portion BA may become thicker toward the end. In other words, the curved surface portion BA can be gradually changed in thickness as it moves away from the plane portion FA.

Referring to FIG. 22 (c), the curved surface portion BA may have a different thickness depending on the position. The curved surface portion BA may include a plurality of bending regions. The thickness of one bending region of the plurality of bending regions may be different from the thickness of the other bending region. The thickness of at least one of the plurality of bending regions may be constant. The thickness of at least one of the plurality of bending areas may be gradually changed along the length direction. For example, the curved portion BA may include a first bending region BN1 and a second bending region BN2. The thickness of the first bending region BN1 may become thinner as it is away from the plane portion FA. The thickness of the second bending region BN2 may become thicker as it is away from the first bending region BN1.

As described above, the tempered glass 301 according to the third embodiment of the present invention may include a curved portion BA having a different thickness depending on the position. When the curved surface portions BA have different thicknesses depending on positions, the thickness of the remaining compressive stress layer varies depending on the position. When the thickness of the compressive stress layer varies with the position of the curved surface portion BA, the bending curvature can be different depending on the position. Therefore, the third embodiment of the present invention can provide tempered glass 301 having different bending curvatures depending on positions.

Referring to Fig. 23, at least one point of the curved portion BA may be different in thickness from at least another point of the curved portion BA. At this time, at least another point of the curved surface portion BA may be a plurality of points. For example, the curved surface portion BA may include at least one groove. The depth of at least one of the plurality of grooves may be different from the depth of the other. The width of at least one of the plurality of grooves may be different from the width of the other. In addition, any one of the plurality of grooves and the other one may be formed to have predetermined intervals. The bending curvature of the curved surface portion BA can be set by adjusting the interval between the grooves. When a plurality of grooves are formed in the curved surface portion BA, the intervals between the grooves may be equal to each other or different from each other.

For example, the curved surface portion BA may include a first groove H1, a second groove H2, and a third groove H3. The width w1 of the first groove, the width w2 of the second groove, and the width w3 of the third groove may be equal to each other. The depth d1 of the first groove, the depth d2 of the second groove, and the depth d3 of the third groove may be different from each other. The interval p1 between the first groove H1 and the second groove H2 and the interval p2 between the second groove H2 and the third groove H3 may be different from each other.

As described above, the tempered glass 301 according to the third embodiment of the present invention may include at least one grooved curved portion BA. When the shape and forming position of the grooves formed in the curved surface portion BA are different, the thickness of the remaining compressive stress layer varies depending on the position of the curved surface portion BA. When the thickness of the remaining compressive stress layer varies depending on the position of the curved surface portion BA, the bending curvature may be different depending on the position. Therefore, the third embodiment of the present invention can provide the tempered glass 301 having different bending curvatures depending on the formed positions of the grooves.

Also, the curved surface portion BA is liable to be damaged by an external force. In the third embodiment of the present invention, the surface area can be increased by forming the grooves in the curved surface portion BA, and the damage due to the external force can be effectively prevented as the stress is dispersed by increasing the surface area.

Referring to FIG. 24, the filler 340 may be filled in the groove formed in the curved portion BA. The filling material 340 is preferably a transparent resin that transmits light. The filler material 340 may be appropriately selected from known resins. For example, the filler material 340 may include a transparent acrylic resin, an epoxy resin, a urethane resin, or the like. Further, it is preferable that the filling material 340 is formed of a material having good adhesion to the glass substrate. The filler material 340 is preferably formed of a material having excellent optical characteristics in order to prevent the visibility of the light incident on the user through the glass substrate and the filler material 340 from being lowered. In addition, it is preferable that the filling material 340 is a material having a transmittance and / or a refractive index equal to that of the glass substrate.

Referring to FIG. 25, the tempered glass 301 according to the third embodiment of the present invention may include a plurality of curved portions BA extending from a plane portion FA. For example, the tempered glass 301 may include a first curved portion BAL extending from one side of the plane portion FA and a second curved portion BAR extending from the other side of the plane portion FA . At this time, the sectional shape of the first curved portion BAL and the sectional shape of the second curved portion BAR may be different from each other. In this case, the curvatures of the first curved portion BAL and the second curved portion BAR may be different from each other.

According to the third embodiment of the present invention, it is possible to provide the tempered glass 301 which can be designed variously in the cross-sectional shape of the curved surface portion BA and can adjust the curvature corresponding thereto and which is improved in aesthetics and design convenience .

<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. 26 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. 26 (a), the tempered glass 1, 201, 301 according to the present invention may be a cover glass (CW) of a display device having a curved portion. 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 a driving element for implementing an image, and a touch screen panel (TSP) for sensing movement of a user's hand and / or a conductor. In such a case, the cover glass (CW) disposed on the touch screen panel TSP needs to be thinned to prevent thinning of the touch sensing sensitivity and to be reinforced so that it is not easily broken by an external impact. In addition, corresponding to the variably varying display devices, a cover glass (CW) including a curved portion needs to be used. Therefore, the tempered glass (1, 201, 301) according to the present invention can perform all the functions described above, and can be suitable as a cover glass (CW) of a display device.

As another example, referring to Fig. 26 (b), the tempered glass 1, 201, 301 according to the present invention may be a protective film PF for protecting the cover glass of the display device. (Hereinafter referred to as "tempered glass film") is used as the protective film PF for protecting the cover glass CW of the display device DD. It is necessary to secure the mechanical strength required to protect the cover glass (CW) provided on the outermost side of the display device DD. Further, in order to improve the esthetics, it is necessary to cope with various mold release products, and it is necessary to be thin to prevent an increase in thickness. Therefore, the tempered glass 1, 201, 301 according to the present invention can satisfy such a demand, and can be used as a tempered glass film (for example, a tempered glass) for protecting the cover glass CW provided at the outermost corner of the display device DD PF).

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, 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: glass substrate
FA: flat portion BA: curved portion
20, 220: Compressive stress layer 30:
240: filling layer 340: filling material
PF: Tempered glass film

Claims (18)

A tempered glass having a flat surface portion and a curved surface portion bent from the flat surface portion,
Wherein a thickness of at least one point of the curved portion is thinner than a thickness of the flat portion. The method according to claim 1,
The curved-
Tempered glass with different thicknesses depending on position. 3. The method of claim 2,
Further comprising a step formed along a boundary between the planar portion and the curved portion. 3. The method of claim 2,
The curved-
And the thickness of the tempered glass is reduced toward the end of the curved surface portion. 3. The method of claim 2,
The curved-
Wherein the thickness of the tempered glass is increased toward the end of the curved surface portion. 3. The method of claim 2,
Wherein the curved surface portion includes a plurality of bending regions,
Wherein the thickness of at least one bending region is different from the thickness of the other bending region. 3. The method of claim 2,
Wherein the curved surface portion includes a plurality of bending regions,
Wherein the thickness of at least one of the bending regions is constantly or gradually changed. 3. The method of claim 2,
The curved-
Wherein the bending curvature differs depending on the position. The method according to claim 1,
The curved-
A tempered glass comprising one or more grooves. 10. The method of claim 9,
Wherein at least one of the plurality of grooves has a different depth from the other. 10. The method of claim 9,
Wherein at least one of the plurality of grooves is different in width from one another. 10. The method of claim 9,
Wherein one of the plurality of grooves and the other of the plurality of grooves has a predetermined gap. 13. The method of claim 12,
Wherein the gaps between the plurality of grooves are the same or different from one another. 10. The method of claim 9,
Further comprising a filler filled in at least one of said at least one groove. 10. The method of claim 9,
Wherein the glass has different curvatures depending on the positions of the grooves. The method according to claim 1,
The curved-
A first curved surface portion extending from one side of the planar portion; And
And a second curved surface portion extending from the other side of the flat surface portion,
Wherein the curvatures of the first curved surface portion and the second curved surface portion are different from each other. The method according to claim 1,
Wherein at least one point of the curved surface portion,
The tempered glass having a thickness different from at least another point of the curved portion. 18. The method of claim 17,
At least another point of the curved surface portion,
Tempered glass, multiple points.

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