KR20230037134A - Manufacturing method for ultra thin flexible glass and ultra thin glasses manufactured by the same - Google Patents

Abstract

The present invention relates to the manufacture of glass capable of minimizing a defect rate in a manufacturing process while having flexibility to be attached to the surface of a bendable display and the like. Disclosed is a method for manufacturing ultra-thin glass having bendability, wherein a glass original plate is prepared and cut using a laser cutting device, and glass units are laminated to process side surfaces, and are slimmed and strengthened.

Description

Manufacturing method of ultra-thin glass having bendability and ultra-thin glass manufactured thereby

The present invention relates to the manufacture of a protective film and glass, and more particularly, to a method for manufacturing ultra-thin glass capable of ensuring uniform quality in the manufacture of flexible ultra-thin glass.

In recent years, consumer demand for slimming and large-sized portable terminals such as mobile phones, smart phones, tablet PCs, personal digital assistants (PDAs), portable multimedia players (PMPs), and notebooks has increased. demand is increasing.

In order to respond to such slimming requirements, tempered glass having a thin thickness and high strength may be used as a cover glass disposed at the outermost portion of the display. However, such tempered glass is also frequently broken or scratched due to impact generated during use, and it is a general trend to use a protective film to prevent this.

Conventionally, such a protective film was made of a polymer material and used by attaching it to the surface of the cover glass. It works well as a function to prevent daily scratches, but the cover glass is broken or cracked due to impact caused by external causes such as falling. could not prevent the phenomenon.

In order to solve the problems of these conventional protective films, in recent years, a high-strength material is manufactured as a protective film and there are increasing examples of attaching it.

On the other hand, flexible displays have recently appeared to meet consumers' requests for portability and a large screen, and foldable devices of various foldable types are appearing.

However, it is particularly difficult to apply the protective film to devices having a flexible display. That is, in order to apply it to a foldable display, it must be produced in an ultra-thin form so as to have flexibility. However, the manufacturing process is very difficult and the defect rate is high, so when the conventional glass manufacturing method is applied, the reliability of production is very low.

Japanese Patent Application Publication No. 4932059 discloses a method for manufacturing tempered glass in the prior art, and FIG. 1 is a front cross-sectional view showing this.

Looking at this in general, first, a thinned large glass plate 1 is prepared (a), and a reinforcement layer 2 is formed on the glass plate by ion exchange or the like (b). After forming the upper and lower layers in this way, transparent photoresist (photosensitive resin) is uniformly applied to the surface of the reinforcement layer 2, dried, and the exposure hole 5 is formed in the area except for the cutout 4 Photomask (6) is covered and exposed by irradiation with UV light to form a pattern, and the protective film (3) is treated (c). In addition, the cut portion 4 of the glass plate 1 without a protective film is etched (D), the remaining portion is cut (e) through machining, and then the step is polished (f) to complete the process. In the above document, it is known that polishing is performed through a rotary grindstone.

In the case of the mechanical cutting, it is common to use a diamond bite or a foil cutter, but there is a risk of multiple glass breakage due to vibration of equipment and tools, and chips are generated, which causes problems in quality.

Also, in the polishing process or the polishing process, there is a risk of cracks due to chips, and sludge remains on the glass, causing similar defects.

This problem is not seriously apparent in the case of a cover glass having a relatively thick thickness, but in the case of manufacturing a thin glass of about tens of μm, for example, the problem is aggravated and causes a rapid increase in the defect rate.

Such defects lead to problems such as occurrence of abnormal image quality due to refraction of light when used as a protective glass, non-uniformity due to a difference in change rate or thickness during bending, and easy cracking.

The present invention has been made to solve the above problems, and a method for manufacturing ultra-thin glass having bendability that can improve the reliability and economic feasibility of manufacturing ultra-thin glass having bendability by improving the conventional thin glass manufacturing technology, and It is an object to provide an ultra-thin glass manufactured thereby.

In order to solve the above problems, the present invention includes the steps of a) preparing a glass original plate having a set thickness and width, b) attaching a protective film to the glass original plate, and c) separating a glass unit from the glass original plate. d) side polishing step of stacking the cut glass units in a vertical direction and processing them through a side processing device from the side side; It provides a method for manufacturing ultra-thin glass having bendability, which includes a slimming step of removing foreign matter through the flow of an etchant, and f) a strengthening step of chemically reinforcing the surface of the slimmed glass unit.

As a preferred embodiment, the cutting step is half-cutting by applying a laser beam in a vertical direction to form a groove in the glass original plate and breaking it, or full cutting by applying a laser beam in a vertical direction to cut it, or by crossing laser beams in an up-and-down direction. Any one of the cross cutting to cut can be selected.

In addition, in the slimming step, the slimming container containing the etchant is vibrated from side to side to generate an internal flow and remove foreign substances on the surface of the glass unit, and by inertia while vertically moving the jig supporting the glass unit in and out of the etchant At least one of dipping methods for removing foreign matter from the glass unit may be applied.

In addition, the side surface may be polished using a blasting device in a state in which the glass units are stacked.

On the other hand, the present invention provides an ultra-thin glass manufactured by the above manufacturing method, in which foreign substances are removed by shaking and dipping in a slimming step after cutting and side polishing.

According to the present invention, it is possible to significantly improve the quality by removing the cause of damage in the processing process or careless handling that occurs during the manufacturing of conventional thin glass, and by applying the laser cutting method and layered polishing, in particular, glass defects and breakage. It is possible to minimize the generation of chips and sludge, which are the main causes of the problem, and have the effect of improving the reliability of the work process.

In addition, by arranging slimming and strengthening at a later stage after the final cutting and polishing process is completed, the fixed number of the final product is ensured, thereby improving manufacturing reliability for the final glass product, and mass production of ultra-thin glass is possible, enabling use in various wearable devices. And, because there are effects applicable to foldable displays and devices, the marketability is improved.

1 is a front cross-sectional view showing a prior art tempered glass manufacturing method.
2 is a flowchart illustrating a method of manufacturing an ultra-thin glass having bendability according to the concept of the present invention.
3 is a view showing an example of a pattern for cutting an original plate according to the concept of the present invention.
4 is a cross-sectional side view showing a cutting process in the manufacturing method of the ultra-thin glass of the present invention.
5 is a side cross-sectional view showing an embodiment in which the side surface is processed in a laminated form in the method of manufacturing ultra-thin glass according to the present invention.
6 is a conceptual diagram for explaining a slimming process.

Hereinafter, a method for manufacturing ultra-thin glass having bendability according to a preferred embodiment of the present invention and an ultra-thin glass manufactured thereby will be described in detail with reference to the accompanying drawings.

The following examples or experimental examples may be modified in various forms, and the content of the present invention is not limited to the following examples.

Basically, the present invention provides a method for manufacturing ultra-thin glass having bendability in which a glass original plate is prepared and cut using a laser cutting device, glass units are laminated to process the side surface, and then slimming and strengthening are performed. present.

The ultra-thin glass provided in the description of the present invention is described as being secondarily attached and used to protect the surface of a flexible display as an example, but the use of the glass manufactured by the manufacturing method of the ultra-thin glass is not limited.

2 is a flowchart illustrating a method of manufacturing ultra-thin glass according to the concept of the present invention.

a) disk preparation step (S100)

The procedure begins by receiving and inspecting glass originals for processes such as cutting and strengthening. Such a glass original plate is prepared in a thinned state, and, for example, a final glass of about 30 to 40 μm may be produced by inputting an original plate of about 100 μm. However, these numerical values do not limit the present invention. The overall size of the glass original plate before processing may be appropriately determined according to the thickness in consideration of ease of handling and specifications of equipment.

b) protective film attachment step (S200)

In the present invention, since laser cutting is applied and a polishing process is arranged as will be described later for an effective cutting process of ultra-thin glass, it is preferable to attach a protective film first and then proceed with subsequent processes. A process of entirely attaching the dry film to the upper and/or lower side of the original glass plate may be performed.

c) cutting step (S300)

The process of cutting along the cutting line to correspond to the pattern of each glass unit has a significant effect on the final product of the ultra-thin glass. In the cutting or polishing process using the mechanical method of the prior art, in particular, the problem of chip generation is as described above.

In the present invention, for this purpose, a laser cutting method is applied to cut the pattern. The laser cutting device may be applied with a known laser beam generator capable of performing cutting by irradiating a laser beam on a glass original plate. It is a configuration for cutting by irradiating a laser beam, and the laser beam generator for this may include an optical device that adjusts the direction and focus of the laser beam generated from the laser beam generator, such as a beam splitter and a reflecting member. composition may be included.

In this cutting step, the irradiation direction of the laser beam may be substantially perpendicular to the glass original plate, but may also be considered as an inclined direction depending on the selection of the process. Examples for this will be described later.

Note that since the laser beam irradiation method is applied according to the present invention, generation of chips is minimized.

d) side polishing step (S400)

When the cutting process through the application of the laser beam is completed, residual parts and chips may be generated at the edge of each glass unit.

Side surfaces of the glass units need to be polished, and according to the concept of the present invention, the side surfaces are processed in a state in which a plurality of glass units are stacked vertically. In this case, the process can be performed on a plurality of glass units at the same time, which is fast, and since the bending strength is much higher in a stacked state, the stress and strain applied to each glass unit itself are drastically reduced. This means that the flatness of the final product can be guaranteed. In addition, since jigs and tools are not used, the occurrence of dimensional errors due to repetitive work is minimized.

As a preferred embodiment, the side polishing may be performed by applying sandblasting. When sandblasting is applied in this way, the nozzle of the sandblasting device is oriented toward the side and may be simultaneously performed on both sides.

However, a known grinder method as well as various chemical and mechanical polishing methods may be applied to the side polishing process.

e) Slimming step (S500)

In the state in which the cutting and polishing are completed as described above, foreign matter may be removed through an etchant so as to completely remove foreign matter on the surface of the glass, which is the final product.

It should be noted that since slimming is applied after the cutting and polishing process as in the concept of the present invention, the weakness of the strength part is compensated compared to the prior art in the manufacture of ultra-thin glass. That is, when the slimming process is performed first, since the glass original plate is weak in terms of strength, there is a high possibility of defects in the process. Considering this, the slimming step is arranged after the cutting and polishing process.

In the slimming step, immersing and applying the glass unit in a state in which the etchant is immersed is similar to the prior art, but in the present invention, the shaking and dipping processes are performed in parallel to remove sludge in different ways and slimming is performed.

Specific examples related to this will be described later.

The slimming process corrects the final size and completely removes foreign substances on the surface of the glass to ensure quality.

f) Reinforcement step (S600)

In the present invention, the strengthening step is applied after the laser cutting, laminated side polishing and slimming are completed as described above. Since chemical treatment is performed in the strengthening process, which may cause deformation of the glass, it is preferable to place the strengthening process in the final process.

According to one embodiment, an ion exchange method is applied, and for example, a compressive stress layer may be formed by immersing glass units in an aqueous solution containing ions (K+). In some cases, a substrate or glass strengthening method of a process such as air cooling strengthening may be applied, and a detailed description in this regard will be omitted.

3 is a plan view illustrating displaying a cutting pattern on a glass original plate according to an embodiment of the present invention.

When the glass original plate 100 is prepared in a large and ultra-thin shape, a protective film is applied to the upper and lower surfaces, and the glass unit pattern is cut through a laser cutting device as described above.

The shape of the cutting pattern and the application of the cutting line may be varied according to selection.

4 are side cross-sectional views for explaining a cutting process according to an embodiment of the present invention.

In the case of FIG. 4 (a), a half cutting method is shown. The laser cutting device 210 is directed from the upper side of the glass original plate 100 to irradiate the laser beam, and the cutting depth may be formed up to only a part of the thickness of the glass original plate 100 . A process of separating by applying a predetermined mechanical force in which a groove is formed at a predetermined set depth proceeds, and this is defined as breaking.

4 (b) shows a form in which the laser beam completely cuts the glass original plate 100 by applying full cutting.

In the case of the half-cutting and full-cutting, grooves are formed or cut in a direction perpendicular to the glass original plate 100, preferably in an upward direction.

(c) of FIG. 4 shows a cross cutting process, and the laser beams intersect in an oblique direction from the upper and lower sides of the glass original plate 100. The intersection point may be formed in the thickness of the glass original plate 100, preferably at the center of the thickness. In the present invention, since the side lamination polishing process is added as described above, the efficiency of the process can be further increased when such crosscutting is applied.

5 is a side cross-sectional view showing that side processing is applied according to an embodiment of the present invention.

Units of the glass original plate 100 that have been cut can be subjected to a process of removing and flattening irregular shapes on the sides, and being stacked in the vertical direction so that the side surfaces are exposed contributes to ensuring the uniformity of quality. Same as

Thus, the edges are arranged up and down on the laminated side surfaces, and processing is performed in the direction of the laminated side surfaces of the side processing device 220 .

This side processing device 220 may be a grinder, preferably a blasting device may be applied. In the illustrated embodiment, it shows that the blasting device is applied, and the nozzle sprays the abrasive material toward the stacked side surface and flattens it. As described above, due to the application of the laminating and blasting method, the resistance to stress generation is high and the efficiency of polishing is improved, so that the quality is good.

6 is a conceptual diagram showing that a slimming process is performed according to an embodiment of the present invention.

In the present invention, the slimming process for correcting the size is arranged at the final stage of the actual processing process, which is to implement a fixed number in manufacturing.

Such a slimming process may be arranged after the polishing process is completed and before the strengthening process by ion exchange as described above. By arranging slimming after cutting and polishing, the reliability of the process is high.

According to the concept of the present invention, the slimming process can be divided into two processes. (a) of FIG. 6 shows the shaking process. In a state where the etching solution 311 is accommodated in the slimming container 310, the glass unit ( 110), it is possible to completely remove chips and sludge on the surface.

The movement method of the slimming container 310 may be selected from various methods such as linear, non-linear, or rotational, and the etching solution and the time required for etching may be selectively performed in consideration of the removal of foreign matter and the effect on the original plate. will be. Foreign matter generated on the glass surface immersed in this way is removed while the etchant flows.

6(b) shows a dipping process. Such dipping uses the inertia caused by the movement of the glass unit 110 itself, not the slimming container 310 itself. To this end, a jig 320 capable of holding the glass unit 110 may be disposed.

In the shaking process, the slimming vessel 310 moves horizontally from side to side, whereas in the dipping process, the jig 320 and the glass unit 110 move vertically. Accordingly, in the dipping process, the glass unit 110 is repeatedly immersed in the etchant and separated.

According to the manufacturing method of ultra-thin glass having bendability according to the concept of the present invention described above, the cause of damage during processing or careless handling that occurs during the manufacturing of conventional thin glass is eliminated, and by applying the laser cutting method and layered polishing, The quality could be significantly improved.

In particular, it is possible to minimize the generation of chips and sludge, which are the main causes of defects and breakage of glass, and has an advantage of improving reliability in the working process.

In addition, by arranging slimming and strengthening at a later stage after the final cutting and polishing process is completed, the static number of the final product is guaranteed, and the penetration deviation caused by the residual sludge on the glass surface and the curling phenomenon that occurs after etching can be compensated. .

In addition, by subdividing the slimming process and applying shaking and dipping processes, it is possible to guarantee a precise number of fixtures, thereby improving manufacturing reliability for the final glass product, and mass production of ultra-thin glass is possible, enabling various wearable devices and foldable displays. and devices. After all, since it contributes to the improvement of production efficiency and quality of products, it leads to an effect of improving marketability.

In the above, the present invention has been described in detail based on examples and accompanying drawings. However, the scope of the present invention is not limited by the above embodiments and drawings, and the scope of the present invention will be limited only by the content described in the claims below.

100 ... glass disc 110 ... glass unit
210 ... laser cutting device 220 ... side processing device
310 ... slimming container 320 ... jig

Claims (5)

a) preparing a glass original plate having a set thickness and width;
b) attaching a protective film to the original glass plate;
c) cutting with a laser beam emitted from a laser cutting device to separate the glass unit from the original glass plate;
d) a side polishing step of stacking the cut glass units in a vertical direction and processing them from the side using a side processing device;
e) a slimming step of removing foreign matter from the glass unit on which side processing has been completed through the flow of an etchant;
f) a strengthening step of chemically reinforcing the surface of the slimmed glass unit;
According to claim 1,
In step c),
Select either half-cutting in which a laser beam is applied in a vertical direction to form grooves on a glass original plate for breaking, or full-cutting in which a laser beam is applied in a vertical direction for cutting, or cross-cutting in which laser beams cross each other in an up-and-down direction. A method for producing ultra-thin glass having a bendability that is
According to claim 1,
In step e),
A shaking method in which the slimming container containing the etchant is vibrated from side to side to generate internal flow and remove foreign substances on the surface of the glass unit, and a jig that supports the glass unit is vertically moved in and out of the etchant to remove foreign substances from the glass unit by inertia. A method for manufacturing ultra-thin glass having bendability in which at least one of dipping methods is applied.
According to claim 1,
In step d),
A method of manufacturing ultra-thin glass having bendability in which side surfaces are polished using a blasting device in a stacked state of glass units.
An ultra-thin glass manufactured through the method of manufacturing an ultra-thin glass having bendability according to any one of claims 1 to 4,
Ultra-thin glass in which foreign substances are removed by shaking and dipping in the slimming step after cutting and side polishing.

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