KR20210076434A - Foldable cover glass and manufacturing method thereof - Google Patents

Abstract

A foldable cover glass according to the embodiment of the present specification can include: a folding side that intersects a folding axis and has a first thickness etched after polishing; a first chamfer unit that intersects the folding axis, is etched to have a predetermined taper, and corresponds to a polished folding side; a non-folding side that is parallel to the folding axis and is etched; and a second chamfer unit that is parallel to the folding axis, is etched to have a predetermined taper, and corresponds to the non-folding side.

Description

FOLDABLE COVER GLASS AND MANUFACTURING METHOD THEREOF

The present specification relates to a foldable cover glass that can be used in a foldable display and a manufacturing method thereof, and more particularly, to a foldable cover glass capable of optimizing folding characteristics and having excellent productivity, and a manufacturing method thereof.

A display device used for a computer monitor, TV, or mobile phone includes an electroluminescence display apparatus that emits light by itself, and a liquid crystal display (LCD) that requires a separate light source.

An electroluminescent display device is an electroluminescent element, and includes an organic light emitting diode, an inorganic light emitting diode, a quantum dot diode, a perovskite LED, and a micro It may include an LED (micro LED) and the like.

Also, in recent years, a flexible display device, in which a display unit and wiring are formed on a flexible substrate such as plastic, which is a flexible material, so that an image can be displayed even if it is bent like paper, is attracting attention as a next-generation display device.

Glass is used to protect the display surface of such a display device.

The inventors of the present specification have studied a cover glass applicable to a flexible display device. Specifically, a study was conducted on the reliability of the cover glass.

The inventors of the present specification have recognized that the thinner the cover glass, the better the folding properties, but the lower the reliability.

The inventors of the present specification have also recognized that the folding properties of the cover glass can be improved depending on the surface treatment and shape of the side surface of the cover glass.

The inventors of the present specification have also recognized that the productivity of the cover glass may vary depending on the side surface treatment process of the cover glass.

Accordingly, the inventors of the present specification tried to develop a foldable cover glass capable of minimizing a decrease in thickness and improving folding characteristics while improving productivity.

The tasks of the present specification are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the problems as described above, the method for manufacturing a foldable cover glass according to an embodiment of the present specification according to an embodiment of the present specification forms a glass substrate stack to which each of a plurality of glass substrates is fixed by an adhesive member. cutting to size, grinding the side of the cut glass substrate stack, selectively polishing only a portion of the side of the ground glass substrate stack, etching the side of the polished glass substrate stack to form a chamfer; and immersing the chamfered glass substrate stack in a solution to separate each of the plurality of glass substrates fixed to the adhesive member.

According to the characteristics of the present specification, the thickness of each of the plurality of glass substrates may be 0.1T or less

According to another feature of the present specification, each of the plurality of glass substrates may have a thickness of 0.06T to 0.08T.

According to another feature of the present specification, it may further include a dummy glass substrate disposed on the uppermost and lowermost sides of the glass substrate stack.

According to another feature of the present specification, the thickness of the dummy glass substrate may be at least three times thicker than the thickness of the glass substrate.

According to another feature of the present specification, the thickness of the dummy glass substrate may be 300 μm to 400 μm.

According to another feature of the present specification, the selectively polishing only a portion of the side surface of the ground glass substrate stack may be performed by supplying a slurry containing a plurality of silica beads to a brush rotating at a high speed.

According to another feature of the present specification, the selectively polishing only a portion of the side surface of the ground glass substrate stack may selectively polish the side surface crossing the folding axis.

According to another feature of the present specification, the etching of the side surface of the polished glass substrate stack to form the chamfer may include etching the polished glass substrate stack in hydrofluoric acid.

According to another feature of the present specification, the step of separating each of the plurality of glass substrates fixed to the adhesive member by immersing the chamfering glass substrate stack in a solution may be immersed in water at a specific temperature for a predetermined time or longer. .

The foldable cover glass according to an embodiment of the present specification has a folding side that intersects a folding axis and has a first thickness etched after polishing, a folding side that intersects with the folding axis and is etched to have a predetermined taper and correspond to the polished side It may include a first chamfer, a non-folding side etched parallel to the folding axis, and a second chamfered portion parallel to the folding axis and etched to have a predetermined taper and corresponding to the non-folding side.

According to another feature of the present specification, the thickness of the foldable cover glass may be 60 μm to 80 μm, and the first thickness may be 5 μm to 42 μm.

According to another feature of the present specification, the first thickness of the first folding side may be determined in consideration of a critical radius of curvature characteristic.

According to another feature of the present specification, the critical radius of curvature of the foldable cover glass may be 3R or less.

According to another feature of the present specification, the foldable cover glass may be tempered.

The details of other embodiments are included in the detailed description and drawings.

The foldable cover glass according to the present specification has an effect of minimizing a decrease in thickness and improving folding characteristics.

The foldable cover glass according to the present specification has an effect of improving productivity without degrading folding characteristics.

Effects according to the present specification are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a flowchart schematically illustrating a method of manufacturing a foldable cover glass according to an embodiment of the present specification.
2A to 2E are conceptual views schematically illustrating a part of a method of manufacturing the foldable cover glass of FIG. 1 .
3 is a graph comparing characteristics of the foldable cover glass according to an embodiment of the present specification and the foldable cover glass according to a comparative example.
4 is a graph illustrating folding characteristics of a foldable cover glass according to an embodiment of the present specification.

Advantages and features of the present specification and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present specification is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only these embodiments allow the disclosure of the present specification to be complete, and common knowledge in the technical field to which this specification belongs It is provided to fully inform those who have the scope of the invention, and the present specification is only defined by the scope of the claims.

The shape, size, content, angle, number, etc. disclosed in the drawings for explaining the embodiment of the present specification are illustrative and not limited to the matters shown in the present specification. Like reference numerals refer to like elements throughout. In addition, in the description of the present specification, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present specification, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless otherwise explicitly stated.

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between the two parts unless 'directly' is used.

Reference to a device or layer “on” another device or layer includes any intervening layer or other device directly on or in the middle of another device.

Also, although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present specification.

Like reference numerals refer to like elements throughout.

The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present specification is not necessarily limited to the size and thickness of the illustrated component.

Each feature of the various embodiments of the present specification may be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments may be independently implemented with respect to each other or may be implemented together in a related relationship. may be

Hereinafter, the present specification will be described in detail with reference to the drawings.

1 is a flowchart schematically illustrating a method of manufacturing a foldable cover glass according to an embodiment of the present specification. 2A to 2E are conceptual views schematically illustrating some steps of the method of manufacturing the foldable cover glass of FIG. 1 .

The foldable cover glass according to an embodiment of the present specification includes a glass substrate stack providing step (S11), a glass substrate stack cutting step (S12), a glass substrate stack grinding step (S13), a glass substrate stack polishing step (S14), a glass It may be manufactured by etching the substrate stack ( S15 ), separating the glass substrate stack ( S16 ), and strengthening the glass substrate ( S17 ). The completed foldable cover glass refers to a glass substrate capable of protecting the display surface of the foldable display panel while having folding characteristics.

The glass substrate stack providing step ( S11 ) will be described with reference to FIGS. 1 and 2A .

The glass substrate stack providing step S11 should be performed in consideration of optimizing the productivity of the foldable cover glass. Accordingly, the inventors of the present specification disclose a glass substrate stack capable of improving productivity by laminating a plurality of glass substrates 140 . Here, the glass substrate 140 may mean mother glass.

As shown in FIG. 2A , an adhesive member 150 is disposed between each glass substrate 140 to fix the plurality of glass substrates 140 . Accordingly, a glass substrate stack in which the glass substrate 140 and the adhesive member 150 are alternately stacked may be provided. If there is no adhesive member 150 , it is difficult to fix the glass substrate 140 , and there may be a problem in that the glass substrate 140 may collide with each other and be damaged in a subsequent process step.

The size of the glass substrate 140 may be determined according to the processing capacity of the production facility. For example, the glass substrate 140 may have a width of 1 m and a height of 1 m as mother glass. However, the present invention is not limited thereto.

The number of glass substrates 140 stacked may be determined according to the processing capacity of the production facility. For example, the number of laminated glass substrates 140 may be 5 to 20 sheets. However, the present invention is not limited thereto.

The thickness of the glass substrate 140 may be determined in consideration of folding characteristics of the foldable display device. For example, the thickness of the glass substrate 140 may be 60 μm to 80 μm. However, the present invention is not limited thereto. For example, in order to achieve the critical radius of curvature 3R of the foldable cover glass, the thickness of the glass substrate 140 may be 70 μm. In particular, the glass substrate 140 according to an embodiment of the present specification is characterized in that the thickness is considerably thinner than that of a general glass substrate for folding characteristics. Therefore, the glass substrate 140 may be easily damaged even by a small impact. The unit of the critical radius of curvature is mm. That is, 3R means a circle having a radius of curvature of 3 mm.

Accordingly, the dummy glass substrate 160 may be further disposed on the uppermost and lowermost sides of the glass substrate stack. The dummy glass substrate 160 may function to protect the glass substrate 140 . The dummy glass substrate 160 may be provided to protect the laminated glass substrate 140 . The dummy glass substrate 160 may be at least three times thicker than the glass substrate 140 . For example, the thickness of the dummy glass substrate 160 may be 300 μm to 400 μm. Accordingly, when the dummy glass substrate 160 is provided, the glass substrate 140 can be protected and the reliability of the glass substrate stack can be improved. Here, arrow X denotes an X-axis direction, Y denotes a Y-axis direction, and Z denotes a Z-axis direction.

When the above-described glass substrate stack is provided, there is an effect of improving productivity while minimizing damage to the foldable cover glass of a thin film that can be applied to a foldable display panel.

A glass substrate stack cutting step ( S12 ) will be described with reference to FIGS. 1 and 2B .

2B shows a dummy glass substrate 160 of a glass substrate stack in a top view perspective. The step of cutting the glass substrate stack ( S12 ) refers to a step of cutting the glass substrate stack in consideration of the dimensions of the foldable cover glass to be produced. The cut glass substrate stack can be processed to produce a foldable cover glass. As described above, in the glass substrate stack, the glass substrate stack is cut to a predetermined size with the cutting tool 170 in a state in which each of the plurality of glass substrates 140 is fixed by the adhesive member 150 . The cutting size may be determined in consideration of the size of the foldable display panel to which the foldable cover glass is to be applied and a process margin of a post-processing step. Referring back to FIG. 2B , the glass substrate stack may be cut along a preset dotted line with the cutting tool 170 . The cutting tool 170 may be a commonly known computer numerical control tool (CNC tool). However, the present invention is not limited thereto. The size to be cut may be the same size in case of a single model, and may be cut in multiple dimensions in case of a plurality of models. For example, the cut glass substrate stack may have a width of 16.6 cm and a height of 8.3 cm. However, the present invention is not limited thereto.

Referring to FIGS. 1 and 2C , the glass substrate stack grinding step ( S13 ) refers to a step of grinding the side of the cut glass substrate stack with the grinder 180 . That is, the side surface of the cut glass substrate stack may be polished by the grinder 180 . Accordingly, the surface roughness of the side surface of the glass substrate 140 roughly cut by the cutting tool 170 may be reduced, and fine cracks and chips on the side surface may be substantially removed.

In other words, cracks or chips are causes of damage to the foldable cover glass when the foldable cover glass is folded.

Specifically for the glass substrate stack grinding step (S13), the grinder 180 follows the arrow shown in FIG. 2C to polish the edge of the glass substrate stack, that is, all sides of the cut glass substrate 140. have. That is, all sides of the glass substrate stack can be polished. In other words, the side surface in the Y-axis direction and the side surface in the X-axis direction of FIG. 2C may be polished. However, the planar shape of the glass substrate stack according to an embodiment of the present specification is not limited to a quadrangle, and may have a shape other than a quadrangle, such as a circle or a polygon.

The grinder 180 polishes all the side surfaces of the glass substrate 140 , the adhesive member 150 , and the dummy glass substrate 160 . At this time, the adhesive member 150 fixes the glass substrate 140 and fills the space of the glass substrate 140 . Accordingly, there is an effect that can block the particles and powders polished by the grinder 180 from penetrating into the glass substrate stack by the adhesive member 150 .

Referring to FIGS. 1 and 2D , the glass substrate stack polishing step S14 refers to a step of selectively polishing only a portion of the side surface of the ground glass substrate stack.

Polishing uses a high-speed rotating brush 190 to process the side of the ground glass substrate stack. In the polishing, the side polished by the grinder 180 may be more finely processed. The polishing process may also be referred to as a polishing process or a mirror finishing process. According to the method for manufacturing a foldable cover glass according to an embodiment of the present specification, when the brush 190 rotates at a high speed, the side surface of the glass substrate stack is selectively polished by supplying a slurry containing fine silica beads. characterized. The slurry may also be referred to as a polishing gel or polishing solution.

Hereinafter, selective polishing will be specifically described. As described above, the polishing process is a process that takes a relatively large amount of time and can greatly affect the productivity of the foldable cover glass.

Referring to FIG. 2D , a folding axis of the foldable cover glass corresponding to the foldable display panel is illustrated. The folding axis may mean an axis serving as a folding standard when the foldable cover glass is folded. According to the method for manufacturing a foldable cover glass according to an embodiment of the present specification, only the side that crosses the folding axis of the grinded glass substrate stack may be selectively polished. As shown in FIG. 2D , both sides of the brush 190 may be polished while moving in the direction of the arrow along both sides crossing the folding axis. That is, only the side surface of the glass substrate stack in the Y-axis direction is polished.

To elaborate on the selective polishing, the completed foldable cover glass may be attached to the foldable display panel, and the foldable display panel may be configured to have a folding axis. The completed foldable cover glass may be folded based on the folding axis. At this time, the foldable cover glass is bent or deformed by an external force when folded based on the folding axis. In addition, the side surface of the foldable cover glass may receive the greatest tensile stress around the folding axis.

If there are fine cracks or chips around the folding axis, there may be a problem that the foldable cover glass can be easily broken. However, through selective polishing, it is possible to remove minute cracks or chips existing in a specific area where tensile stress is generated. Therefore, there is an effect that can improve the folding characteristics of the foldable cover glass. To elaborate, it is also possible to polish the side that does not intersect the folding axis. However, in this case, there may be a problem in that only a polishing time is increased without substantially improving the folding characteristics, and a problem of lowering productivity occurs. In addition, since silica beads are included in the slurry supplied during polishing, the adhesive member 150 is scraped off relatively more than the glass substrate 140 by the high-speed rotating brush 190 and the slurry, and the glass substrate ( 140), a gap is created between them. Accordingly, there is an effect that the chamfering can be easily formed through the etching of the protruding portion in the glass substrate stack etching step ( S15 ), which will be described later.

If the polishing process is performed on all sides of the glass substrate stack, for example, the side surfaces in the X-axis direction and the Y-axis direction, the slurry is formed at the corner of the glass substrate stack (the point where the X-axis and the Y-axis intersect). The adhesive member 150 is relatively further removed. Accordingly, the adhesive member 150 may not be able to sufficiently support the edge, and the edge of the glass substrate may be damaged. In addition, if all sides are uniformly polished for the same time, the side that intersects the folding axis may not be sufficiently polished. Accordingly, cracks and chip removal on the side intersecting the folding axis can be made less than in the case of selective polishing. Accordingly, when polishing is performed for the same time, the folding characteristics may be deteriorated.

However, if only the side that crosses the folding axis is selectively polished according to the manufacturing method of the foldable cover glass according to the exemplary embodiment of the present specification, the folding characteristic can be improved while shortening the process time.

A glass substrate stack etching step ( S15 ) will be described with reference to FIGS. 1 and 2E . 2E is an enlarged view of a portion of a side surface of a glass substrate stack on which an etching process is performed after polishing.

The glass substrate stack is immersed in an etching solution for a predetermined time. Thus, the sides of the glass substrate stack are etched in proportion to the immersion time.

As described above, during the polishing process, since the adhesive member 150 was cut out more inward than the glass substrate 140 by the brush and the slurry, while etching from the edge of the protruding glass substrate 150, the glass substrate edge has a taper. is formed The solution used for the etching may be, for example, hydrofluoric acid. However, the present invention is not limited thereto.

That is, a taper is formed between the upper surface, the lower surface, and the side surface of the glass substrate 140 . Here, the thickness W1 and the thickness W2 of the glass substrate 140 of the side excluding the area cut out by the taper are shown. The thickness of the side will be described in detail later with reference to FIG. 4 .

If the polishing process is not performed, since the adhesive member 150 is not substantially removed, the glass substrate 140 may not protrude. In this case, even if the etching process is performed, the taper may not be substantially formed on the glass substrate 140 . However, the glass substrate 140 protrudes more than the adhesive member 150 by the polishing process, and when etching is performed in this state, there is an effect that a taper can be naturally formed.

If etching is performed without a polishing process, even if the etching time is increased, it is difficult to form a desired level of taper. Also, even if a desired level of taper is formed with a grinder, grinding is impossible because the thickness of the glass substrate 140 is too thin. Therefore, if the etching process is performed after the polishing process, the taper of the thin-film glass substrate 140 can be easily adjusted to a desired ratio.

In the glass substrate stack separation step ( S16 ), the plurality of stacked foldable cover glasses is separated from the adhesive member 150 by immersing the glass substrate stack in a solution for a predetermined time. In this case, the adhesive member 150 may be a water-soluble adhesive member.

For example, when the adhesive member 150 is glue, the solution may be water at 90 degrees Celsius, and the immersion time may be 30 minutes. In this case, the adhesive force of the adhesive member 150 may be reduced, so that the foldable cover glass may be easily separated from the glass substrate stack. However, the present invention is not limited thereto and may be separated by a conventionally known method according to the characteristics of the adhesive member 150 .

The substrate strengthening processing step S17 may utilize a conventional strengthening processing process. Each of the separated foldable cover glass may be strengthened by a conventionally known method to improve surface strength. For example, the strengthening treatment of the foldable cover glass may be performed through thermal strengthening, chemical strengthening, or the like.

A foldable cover glass may be manufactured from the glass substrate stack according to the manufacturing steps described above. However, since some processes are known in the prior art, the scope of the present specification is not substantially limited.

Referring to FIG. 3 , it is a graph comparing the critical radius of curvature characteristic of the foldable cover glass according to the embodiment of the present specification and the critical radius of curvature characteristic of the foldable cover glass according to the comparative example.

The X-axis of FIG. 3 means a critical radius of curvature Rth. Y-axis means yield (%). A point at which the foldable cover glass is broken when the radius of curvature of the folding part of the folding axis of the foldable cover glass according to the embodiment of the present specification is folded is defined as the critical radius of curvature (Rth). Then, by testing a plurality of samples, a statistically 95% success probability point is defined as a yield (%).

In the Example and Comparative Example shown in FIG. 3, the thickness of the glass substrate is the same as 70 μm. In addition, the horizontal and vertical width|variety of a glass substrate are the same. In addition, the side surface of the glass substrate was ground equally. In addition, the side surfaces of the glass substrate are etched in the same manner to have the same chamfering shape. However, in the example, the side intersecting the folding axis was polished, and in the comparative example, the side intersecting the folding axis was not polished. That is, the embodiment and the comparative example differ only in whether the glass substrate stack polishing step S14 is performed.

When the glass substrate of the example was folded with a radius of curvature of 3.0R, 95% of the foldable glass substrate was not broken. In contrast, in the glass substrate of the comparative example, 55% of the glass substrate was not damaged at a radius of curvature of 3.0R.

That is, it can be seen that the yield at the radius of curvature of the foldable cover glass can be significantly improved depending on the presence or absence of the side polishing process corresponding to the folding axis.

In addition, it can be seen that the critical radius of curvature (Rth) that achieves a yield of 95% through the polishing process is improved from 3.7R to 3.0R.

In more detail, if the thickness of the foldable cover glass is reduced in order to reduce the critical radius of curvature, there is a problem in that it becomes weak against impact. However, according to the method for manufacturing the foldable cover glass according to the embodiment of the present specification, there is an effect that the durability of the foldable cover glass can be maintained while the critical radius of curvature is reduced without reducing the thickness.

4 is a graph of an experiment of the critical curvature radius characteristics of the foldable cover glass according to the taper and side thickness according to the etching process time of the foldable cover glass according to an embodiment of the present specification.

The X-axis of FIG. 4 means the time required for the etching process. The Y-axis means the critical radius of curvature (Rth). The numerical value of the graph means the side thickness W1 of the glass substrate 140 of FIG. 2E . For example, when the thickness W2 of the glass substrate 140 of FIG. 2E is 70 μm, when the etching process is performed for 4 minutes, a taper is formed and the remaining side thickness W1 is 42 μm. When the etching process is performed for 8 minutes, the taper is formed and the remaining side thickness W1 is 33 μm. When the etching process is performed for 12 minutes, the taper is formed and the remaining side thickness W1 is 22 μm. When the etching process is performed for 16 minutes, a taper is formed and the remaining side thickness W1 is 16 μm. When the etching process is performed for 20 minutes, the taper is formed and the remaining side thickness W1 is 5 μm.

It is assumed that the second thickness W2 of the glass substrate 140 is 70 μm and will be described below.

When the first thickness W1 is 42 μm, the ratio of the taper to the second thickness W2 is 40% and the ratio of the first thickness W1 is 60%.

When the first thickness W1 is 33 μm, the ratio of the taper to the second thickness W2 is 52% and the ratio of the first thickness W1 is 48%.

When the first thickness W1 is 22 μm, the ratio of the taper to the second thickness W2 is 68% and the ratio of the first thickness W1 is 32%.

When the first thickness W1 is 5 μm, the ratio of the taper to the second thickness W2 is 93% and the ratio of the first thickness W1 is 7%

Referring back to FIG. 4 , it was confirmed that the critical radius of curvature (Rth) characteristic was most excellent when the ratio of the taper was 68%. In addition, it was confirmed that the critical radius of curvature (Rth) can be 3R or less when the taper ratio is 40% to 93%.

According to the above configuration, there is an effect that the critical radius of curvature Rth of the foldable cover glass can be reduced by adjusting the ratio of the taper.

In some embodiments, a foldable cover glass may be attached on the foldable display panel. The foldable cover glass can protect the foldable display panel from external impact, moisture, heat, and the like. The adhesive member for attaching the foldable cover glass and the foldable display panel may be formed of a transparent adhesive member such as Optical Clear Resin (OCR) or Optical Clear Adhesive (OCA). A foldable display panel is a panel on which an image is implemented, and a plurality of pixels for realizing an image and a circuit, wiring, and components for driving the plurality of pixels may be disposed. The foldable display panel may be configured to include a display area and a bezel area. The display area is an area for displaying an image, in which a plurality of pixels are disposed. A circuit unit for driving a plurality of pixels for displaying an image may be disposed in the display area. The bezel area is an area in which an image is not displayed, and is an area in which circuits, wirings, and components for driving a plurality of pixels of the display area are disposed. Various ICs, such as a gate driver IC and a data driver IC, and a driving circuit may be disposed in the bezel area.

In some embodiments, a black matrix may be formed in the bezel area of the foldable cover glass. The black matrix may be configured to include materials such as carbon black, black resin, black ink, and visible light absorbing pigments.

A flexible display device according to various embodiments of the present specification may be described as follows.

A method for manufacturing a foldable cover glass according to an embodiment of the present specification includes cutting a glass substrate stack to which each of a plurality of glass substrates is fixed to a predetermined size by an adhesive member, grinding the side of the cut glass substrate stack , selectively polishing only a part of the side surface of the grinded glass substrate stack, etching the side surface of the polished glass substrate stack to form chamfering, and immersing the chamfered glass substrate stack in a solution to fix it to an adhesive member It may include the step of separating each of the glass substrates.

According to the characteristics of the present specification, the thickness of each of the plurality of glass substrates may be 0.1T or less

According to another feature of the present specification, the thickness of the plurality of glass substrates may be 0.06T to 0.08T.

According to another feature of the present specification, it may further include a dummy glass substrate disposed on the uppermost and lowermost sides of the glass substrate stack.

According to another feature of the present specification, the thickness of the dummy glass substrate may be at least three times thicker than the thickness of the glass substrate.

According to another feature of the present specification, the thickness of the dummy glass substrate may be 300 μm to 400 μm.

According to another feature of the present specification, the selectively polishing only a portion of the side surface of the ground glass substrate stack may be performed by supplying a slurry containing a plurality of silica beads to a brush rotating at a high speed.

According to another feature of the present specification, the selectively polishing only a portion of the side surface of the ground glass substrate stack may selectively polish the side surface corresponding to the folding axis.

According to another feature of the present specification, the etching of the side surface of the polished glass substrate stack to form the chamfer may include etching the polished glass substrate stack in hydrofluoric acid.

According to another feature of the present specification, the step of separating each glass substrate fixed to the adhesive member by immersing the chamfering glass substrate stack in a solution may be immersed in water at a specific temperature for a predetermined time or longer.

The foldable cover glass according to an embodiment of the present specification has a folding side that intersects a folding axis and has a first thickness etched after polishing, a folding side that intersects with the folding axis and is etched to have a predetermined taper and correspond to the polished side It may include a first chamfer, a non-folding side etched parallel to the folding axis, and a second chamfered portion parallel to the folding axis and etched to have a predetermined taper and corresponding to the non-folding side.

According to another feature of the present specification, the thickness of the foldable cover glass may be 60 μm to 80 μm, and the first thickness may be 5 μm to 42 μm.

According to another feature of the present specification, the thickness of the first folding side may be determined in consideration of a critical radius of curvature characteristic.

According to another feature of the present specification, the critical radius of curvature of the foldable cover glass may be 3R or less.

According to another feature of the present specification, the foldable cover glass may be tempered.

Although the embodiments of the present specification have been described in more detail with reference to the accompanying drawings, the present specification is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit of the present specification. . Accordingly, the embodiments disclosed in the present specification are for explanation rather than limiting the technical spirit of the present specification, and the scope of the technical spirit of the present specification is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present specification should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present specification.

140: glass substrate
150: adhesive member
160: dummy glass substrate
170: cutting tool
180: grinder
190: brush

Claims (15)

Cutting the glass substrate stack to which each of the plurality of glass substrates is fixed by an adhesive member to a predetermined size;
grinding a side surface of the cut glass substrate stack;
selectively polishing only a portion of a side surface of the ground glass substrate stack;
forming a chamfer by etching a side surface of the polished glass substrate stack; and
and separating each of the plurality of glass substrates fixed to the adhesive member by immersing the chamfered glass substrate stack in a solution. According to claim 1,
The thickness of each of the plurality of glass substrates is 0.1T or less, foldable cover glass manufacturing method. 3. The method of claim 2,
Each of the plurality of glass substrates has a thickness of 0.06T to 0.08T. According to claim 1,
and dummy glass substrates disposed on the uppermost and lowermost sides of the glass substrate stack. 5. The method of claim 4,
The thickness of the dummy glass substrate is at least 3 times thicker than the thickness of the glass substrate, the foldable cover glass manufacturing method. 6. The method of claim 5,
The thickness of the dummy glass substrate is 300 μm to 400 μm. According to claim 1,
The method for manufacturing a foldable cover glass, characterized in that the selectively polishing only a portion of the side surface of the ground glass substrate stack comprises polishing by supplying a slurry containing a plurality of silica beads to a brush rotating at a high speed. According to claim 1,
The method for manufacturing a foldable cover glass, characterized in that the selectively polishing only a part of the side surface of the ground glass substrate stack comprises selectively polishing a side surface crossing the folding axis. According to claim 1,
The forming of the chamfering by etching the side surface of the polished glass substrate stack comprises etching the polished glass substrate stack in hydrofluoric acid. According to claim 1,
Separating each of the plurality of glass substrates fixed to the adhesive member by immersing the chamfering glass substrate stack in a solution comprises immersing in water at a specific temperature for a predetermined time or longer, foldable cover How to make glass. a folding side that intersects the folding axis and has a first thickness etched after polishing;
a first chamfer that intersects the folding axis and is etched to have a predetermined taper and correspond to the polished folding side surface;
a non-folding side etched parallel to the folding axis; and
and a second chamfered portion parallel to the folding axis and etched to have a predetermined taper and correspond to the non-folding side surface. 12. The method of claim 11,
The foldable cover glass has a thickness of 60 μm to 80 μm, and the first thickness is 5 μm to 42 μm. 13. The method of claim 12,
A first thickness of the first folding side is determined in consideration of a critical radius of curvature characteristic. 13. The method of claim 12,
The foldable cover glass, characterized in that the critical radius of curvature of the foldable cover glass is 3R or less. 12. The method of claim 11,
The foldable cover glass is characterized in that it has been strengthened.

Images