KR20150040491A - Method for Champering of a window substrate - Google Patents

Abstract

The present invention relates to a method for chamfering a window substrate and, more specifically, to a method for chamfering a window substrate comprising: a step of grinding a cutting plane by injecting a grinding agent to the cutting plane of a window substrate and indenting a cylindrical brush, to the outer circumference of which hair having a length between 14 and 25 mm is attached and which rotates at a rate between 700 and 5,000 rpm, to the cutting plane at a distance between 6 and 10 mm from the outer circumference; and a step of wet-etching the cutting plane of the grinded window substrate. Therefore, the method for chamfering a window substrate improves the elongation percentage of the window substrate, thereby preventing the fracture of the window substrate.

Description

[0001] The present invention relates to a method for chamfering a window substrate,

The present invention relates to a method of chamfering a window substrate.

Generally, the cutting and chamfering process of the flat panel display window substrate is performed in the following manner.

First, there is a mechanical cutting method. The system is mechanically engraved on the glass plate by dragging the diamond or carbide grinding wheel across the glass surface, and then cutting the glass plate along the scale to produce a cut edge. Typically, such a mechanical cutting method results in a lateral crack at a depth of about 100 to 150 탆, which cracks originate from the cutting line of the chewing wheel. Since the lateral crack reduces the strength of the window substrate, the cut portion of the window substrate must be polished and removed.

Next, there is a non-contact cutting method through a laser. The method is based on the fact that as the laser expands the glass surface by moving along a predetermined path on the glass surface past the check at the edge of the window substrate, the cooler moves along its trailing edge to stretch the surface, The crack is thermally propagated to cut the window substrate.

The cutting portion of the above-mentioned mechanical or laser-cut window substrate is sharp and its surface is uneven and is vulnerable to external impact, so it must undergo chamfering process.

The chamfering process generally includes a two-step process for etching the cut portion, that is, polishing the wafer by rotating the polishing wheel for chamfering, and then etching the wafer with an etchant to prevent cracking of the edge portion due to a minute crack at the chamfered portion It goes through.

Through the chamfering process, the smoothness of the cut portion is improved and the strength is increased. However, it is difficult to provide a window substrate having an excellent elongation by the conventional chamfering process.

Korean Patent No. 895830 discloses an edge processing method of a flat panel display glass substrate.

Korean Patent No. 895830

An object of the present invention is to provide a chamfering method of a window substrate which can obtain a window substrate having an excellent elongation.

1. A cylindrical brush having a length of 14 to 25 mm and attached to an outer circumferential surface and rotating at 700 to 5,000 rpm is pressed into the outer circumferential surface so as to be spaced 6 to 10 mm from the cutting surface, ; And wet etching the cut surface of the polished window substrate.

2. The method of claim 1, wherein the simulated diameter is 0.05 to 0.5 mm.

3. The method for chamfering a window substrate according to 1 above, wherein the corrugation is formed of synthetic fibers.

4. The method of claim 1, wherein the brush moves at a speed of 50 to 1000 mm / minute along the cut surface of the window substrate and performs polishing.

5. The method of claim 1 wherein said abrasive is selected from the group consisting of molten aluminum oxide particles, silicon carbide, boron carbide, titanium carbide, diamond, cubic boron nitride, garnet, tripoly, chromium oxide, cerium oxide, molten alumina- - at least one member selected from the group consisting of lead abrasive particles.

6. The method of claim 1, wherein the abrasive has a particle size of at least 2,000 mesh.

7. The method of claim 1, wherein the wet etching is performed by immersing the window substrate in an etching solution containing a fluorine compound, or spraying the etching solution onto a cutting surface.

8. The method of claim 7, wherein the etchant comprises 4 to 12% by weight of a fluorinated compound.

9. The method of claim 7, wherein the temperature of the etchant is 15 to 40 占 폚.

10. The method of claim 1, wherein the wet etching is performed for 20 seconds to 10 minutes.

When chamfering is carried out by the method of the present invention, the elongation rate of the substrate is remarkably improved, and therefore the substrate can be prevented from being broken.

A cylindrical brush having a length of 14 to 25 mm and attached to an outer circumferential surface and rotating at 700 to 5,000 rpm is press-fitted so that its outer circumferential surface is spaced 6 to 10 mm away from the cut surface, Polishing; And a step of wet-etching the cut surface of the polished window substrate, thereby remarkably improving the elongation of the window substrate and thereby suppressing breakage of the substrate.

Hereinafter, the present invention will be described in more detail.

The window substrate subjected to the cutting process is in a state where the strength is remarkably lowered, there are micro cracks on the cut surface, and the cut surface is sharp, so a chamfering process is required.

As such a chamfering method, a method of performing polishing by abrading the abrasive wheel to a cut surface or a method of further performing an etching process after polishing has been typically used. In the case of a window substrate, particularly a window substrate formed of tempered glass, It is difficult to achieve uniform elongation due to a uniform chamfering process by preventing fine cracks from uniformly transferring energy.

In order to solve the above problems, the present invention can remarkably improve elongation by performing brush polishing and wet etching under specific process conditions.

Brush polishing is a method in which a rotating brush is brought into contact with a cut surface of a window substrate to polish the cut surface more evenly. As a result, fine cracks existing on the surface are polished to reinforce the cut surface.

The brush according to the present invention is a cylindrical brush, and is attached to the outer circumferential surface.

The simulated length of the brush is 14 to 25 mm. When the simulation length is less than 14 mm, the abrasive to be described later is difficult to adhere to the hair, resulting in poor polishing efficiency. If the simulated length is more than 25 mm, the hair may be knocked down, tangled and twisted, so that chamfering of the cut surface is performed nonuniformly. In this respect, it may preferably be 14 to 22 mm, more preferably 14 to 20 mm.

The simulated diameter of the brush is not particularly limited, and may be, for example, 0.05 to 0.5 mm when the simulated length is 15 to 25 mm. When the simulated diameter is less than 0.05 mm, the abrasive to be described later is difficult to adhere to the hair, and the polishing efficiency may be lowered. If the simulated diameter is larger than 0.5 mm, it may be thicker than a normal window substrate, which may damage the window substrate. In this respect, it may preferably be 0.1 to 0.4 mm, more preferably 0.15 to 0.3 mm.

The simulated material is not particularly limited and may be made of synthetic fibers conventionally used in the art, and may be, for example, nylon.

The brush is press-fitted so that its outer circumferential surface is spaced apart from the cut surface by a predetermined distance, so that the bristles sufficiently come into contact with the cut surface to perform polishing.

In the present invention, the indentation distance is a distance between the cut surface of the window substrate and the outer peripheral surface of the brush after the brush is press-fitted.

The indentation distance of the brush may be 6 to 10 mm when the simulation length is 14 to 25 mm. If the indentation distance is less than 6 mm, the contact between the wax and the cut surface may be excessive, and an excessive load may be applied to the process equipment at the time of polishing, thereby reducing the service life of the equipment. When the indentation distance exceeds 10 mm, the contact between the wax and the cut surface is insufficient and the polishing efficiency decreases. In this respect, it may preferably be 6 to 9 mm, more preferably 6 to 8 mm.

The cutting of the cut surface is performed by the rotation of the brush.

The rotation speed of the brush may be 700 to 5,000 rpm. If the rotation speed is less than 700 rpm, the process efficiency may be lowered. If the rotation speed exceeds 5,000 rpm, an excessive load is applied to the window substrate, which may lead to substrate breakage. From such a viewpoint, it is preferably 1,000 to 4,000 rpm, more preferably 1,200 to 3,000 rpm.

The brush contacts the cut surface of the window substrate and moves along the cut surface.

The moving speed of the brush is not particularly limited, and may be, for example, 50 to 1,000 mm / min. When the moving speed of the brush is less than 50 mm / minute, the brush may not move to the next part even after the polishing is sufficiently performed to the required level. When the moving speed of the brush is more than 1,000 mm / min, polishing may be difficult to be performed sufficiently. From such a viewpoint, it is preferably 100 to 800 mm / min, more preferably 120 to 600 mm / min.

The polishing step according to the present invention is carried out by spraying an abrasive.

The abrasive is sprayed between the cut surface of the window substrate, the brush of the brush or between the brush and the cut surface.

The sprayed abrasive is distributed on the cut surfaces, the wafers and the like of the window substrate, and in this state, the polishing of the cut surface is performed by charging the brush which is in contact with the cut surface.

As the abrasives, abrasives conventionally used in the art can be used. Examples of the abrasives include fused aluminum oxide (including white fused alumina, heat-treated aluminum oxide and brown aluminum oxide), silicon carbide : Boron carbide, titanium carbide, diamond, cubic boron nitride, garnet, tripoli (microcrystalline SiO ₂ ), chromium oxide, cerium oxide, molten alumina-zirconia , Sol-gel-induced abrasive particles, and the like. These may be used alone or in combination of two or more.

It is preferable that the abrasive is fine so that fine cracks or the like can be more evenly polished without damaging the cut surface, and may be fine particles of 2,000 mesh or more, for example. When the particle size is within the above range, it is possible to uniformly polish the cut surface without damaging it. From such a viewpoint, it may preferably be 2,000 to 10,000 meshes.

The chamfering method of the window substrate of the present invention can significantly improve the elongation of the window substrate by performing the brush polishing within the range satisfying all the above specific conditions and performing the wet etching described later. In particular, it can be advantageously applied to the case where the window substrate is reinforced glass having a plurality of fine cracks on the cut surface.

In the method of chamfering a window substrate of the present invention, the cut surface of the polished window substrate is wet-etched after the brush polishing process.

The etching process improves the smoothness of the chamfered portion and further improves the elongation of the brush polished window substrate under the above conditions.

The etching method is not particularly limited. For example, the window substrate may be immersed in an etchant commonly used in the art, or the etchant may be sprayed onto the cut surface. Preferably, the etch is performed by immersing the window substrate in an etchant can do.

The etching solution according to the present invention includes fluorine compounds. The fluorine compound is not particularly limited as long as it is a compound capable of emitting fluorine ions in an aqueous solution as a main component for etching a window substrate, and a compound commonly used in the art can be used.

The content of the fluorine compound is not particularly limited and may be, for example, 4 to 12% by weight, preferably 4 to 10% by weight, and more preferably 5 to 9% by weight based on the total weight of the etching solution. When the content of the fluorine compound is 4 to 12% by weight, the effect of improving the elongation can be maximized.

If necessary, the etchant according to the present invention may further include an additive having etchability, which is commonly used in the art, in addition to fluorine compounds for improving etching performance.

The etching solution may further include additives such as surfactants conventionally used in the art as needed, and it includes residual water.

The temperature of the etching solution is not particularly limited and can be suitably selected. For example, it may be 15 to 40 캜, preferably 18 to 38 캜, more preferably 20 to 35 캜. When the temperature of the etching solution is within the range of 15 to 40 占 폚, the influence due to the temperature difference with the window substrate can be minimized, and the effect of improving the elongation can be maximized.

The execution time of the etching process is not particularly limited within the range capable of performing the above function, and can be, for example, 20 seconds to 10 minutes, preferably 1 minute to 8 minutes, more preferably 1 minute to 5 minutes Minute. When the execution time of the etching process is 20 seconds to 10 minutes, the smoothness of the polished surface can be sufficiently improved and the effect of improving the elongation can be maximized.

In the present invention, the window substrate is not particularly limited as long as it is durable enough to be protected from external force by being applied to a liquid crystal display device, a touch screen panel, and the like, Can be used without any particular limitation. For example, glass, polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET) polyethyelene terepthalate, polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate acetate propionate, CAP), and the like can be used. Preferably, glass can be used, and more preferably, tempered glass can be used.

The object to which the window substrate according to the present invention is applied is not particularly limited. For example, it may be used as a transparent protection window of a monitor, a television, or the like, or may be applied to a touch screen panel or the like.

When the window substrate is applied to the touch screen panel, a laminated structure including electrode patterns may be formed on one surface thereof before chamfering.

Such a laminated structure can be adopted without limitation for the lamination structure known in the art depending on the specific use of the touch screen panel and the like. For example, at least one or more layers of an electrode pattern, an insulating layer, a BM, an index matching layer (transparent dielectric layer), a protective layer, and a scattering prevention layer may be used to form a stacked structure in various order. no.

The electrode pattern detects the static electricity generated by the human body and connects it to the electric signal when the finger is brought into contact with the display part which is the touch area of the image sensor.

The conductive material used for forming the electrode pattern is not particularly limited and examples thereof include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), cadmium tin oxide ), PEDOT (poly (3,4-ethylenedioxythiophene)), carbon nanotubes (CNT), and metal wires. These may be used alone or in combination of two or more.

The metal used for the metal wire is not particularly limited, and examples thereof include silver (Ag), gold, aluminum, copper, iron, nickel, titanium, tellurium, chromium and the like. These may be used alone or in combination of two or more.

An electrode pattern circuit may be formed on the non-display portion corresponding region of the electrode pattern. The electrode pattern circuit serves to transmit an electrical signal generated in the electrode pattern to the FPCB, an IC chip or the like by touching the window substrate display portion. The electrode pattern circuit can be formed by the same method using the same material as the electrode pattern.

The insulating layer prevents electrical shorting of the electrode. The material is not particularly limited, and may be formed of, for example, a metal oxide such as silicon oxide, a polymer, and an acrylic resin.

The BM (nonconductive pattern) forms an opaque decorative layer in the non-display portion at the edge of the window substrate so that the display portion, which is the touch region, is partitioned at the central portion of the window substrate in order to prevent the substrate,

The nonconductive pattern may be formed of a conventionally used composition for forming a nonconductive pattern including a binder resin, a polymerizable compound, a polymerization initiator, a pigment, a solvent and the like.

The composition for forming a nonconductive pattern may further comprise a nonconductive metal, a nonconductive oxide or a mixture thereof.

The kind of the nonconductive metal is not particularly limited, and examples thereof include tin or a silicon aluminum alloy.

The kind of the nonconductive oxide is not particularly limited, and examples thereof include titanium dioxide (TiO ₂ ), silicon dioxide (SiO ₂ ), and mixtures thereof.

The index matching layer may be formed comprising niobium oxide, silicon oxide, or mixtures thereof.

The protective layer serves to prevent contamination and breakage of the laminated structure including the electrode pattern from the outside.

The anti-scattering layer protects each of the patterns and prevents scattering of the window substrate when the window substrate ruptures.

The material of the anti-scattering film provides durability and is not particularly limited as long as it is a transparent material, and may be, for example, PET (polyethylen terephthalate).

The method of forming the anti-scattering film is not particularly limited, and examples thereof include a spin coating method, a roll coating method, a spray coating method, a dip coating method, a flow coating method, a doctor blade method, inkjet printing, screen printing, pad printing, gravure printing, offset printing, flexography printing, stencil printing, imprinting, and the like.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention and are not intended to limit the scope of the claims. It will be apparent to those skilled in the art that such variations and modifications are within the scope of the appended claims.

Example  1 to 11 and Comparative Example  1 to 6

The brush polishing process was performed on the cut surfaces of the window substrate (IOX-FS, Corning) cut by a non-contact cutting method using a laser according to the conditions shown in Table 1 below. Niobium powder was used and cerium oxide was used as an abrasive. Then, the substrate was immersed in a 7% HF aqueous solution to perform an etching process.

division mother brush Abrasive Etchant Length
(mm) diameter
(mm) Indentation distance
(mm) Rotation speed
(rpm) speed
(mm / min) size
(Mesh) Temperature
(° C) Immersion
time
(second) Example 1 17 0.2 8 2500 360 2500 25 180 Example 2 15 0.2 6 2500 360 2500 30 180 Example 3 25 0.2 9 2500 360 2500 25 240 Example 4 17 0.6 8 2500 360 2500 25 180 Example 5 15 0.03 8 2500 360 2500 25 180 Example 6 17 0.2 10 2500 360 2500 22 300 Example 7 17 0.2 8 2500 1100 2500 22 180 Example 8 17 0.2 6 2500 360 2500 25 180 Example 9 17 0.2 8 2500 360 2500 10 180 Example 10 17 0.2 8 2500 360 2500 43 180 Example 11 17 0.2 8 2500 360 2500 25 660 Comparative Example 1 12 0.2 8 2500 360 2500 25 180 Comparative Example 2 27 0.2 8 2500 360 2500 25 180 Comparative Example 3 17 0.2 5 2500 360 2500 25 180 Comparative Example 4 17 0.2 12 2500 360 2500 25 180 Comparative Example 5 17 0.2 8 600 360 2500 25 180 Comparative Example 6 17 0.2 8 6000 360 2500 25 180

Experimental Example . Elongation  Measure

The elongation ratios of the window substrates subjected to chamfering in the above Examples and Comparative Examples were obtained by providing two support spans 4 mm apart from the center of the substrate on both sides of the window substrate, Were added.

The distance from the point where the upper span contacts the window substrate to the point where the window substrate is broken is measured to evaluate the elongation represented by the following Equation 1. The results are shown in Table 2 below.

[Equation 1]

Elongation (%) = (6T?) / S ²

(Where T is the thickness (mm) of the window substrate,? Is the crosshead displacement (mm), and s is the distance between the support spans (mm)).

division Elongation (%) division Elongation (%) Example 1 1.82 Example 10 1.18 Example 2 1.94 Example 11 1.51 Example 3 1.85 Comparative Example 1 0.53 Example 4 1.08 Comparative Example 2 0.56 Example 5 1.07 Comparative Example 3 0.48 Example 6 1.84 Comparative Example 4 0.46 Example 7 0.93 Comparative Example 5 0.51 Example 8 1.91 Comparative Example 6 0.42 Example 9 1.05 - -

Referring to Table 2, it can be confirmed that the window substrates subjected to the chamfering by the methods of Examples 1 to 11 have a very good elongation.

However, the window substrates subjected to chamfering by the methods of Comparative Examples 1 to 6 had very low elongation.

Claims (10)

Pressing the abrasive on the cut surface of the window substrate and pressurizing the cylindrical brush having a length of 14 to 25 mm and attaching the blade to the outer circumferential surface and rotating the blade at 700 to 5,000 rpm so as to be 6 to 10 mm away from the cut surface, ; And
And wet etching the cut surface of the polished window substrate.
The method according to claim 1, wherein the simulated diameter is 0.05 to 0.5 mm.
The method according to claim 1, wherein the preform is made of synthetic fibers.
The method according to claim 1, wherein the brush moves at a speed of 50 to 1000 mm / minute along the cut surface of the window substrate and performs polishing.
The method of claim 1, wherein the abrasive is selected from the group consisting of molten aluminum oxide particles, silicon carbide, boron carbide, titanium carbide, diamond, cubic boron nitride, garnet, tripoly, chromium oxide, cerium oxide, molten alumina-zirconia and sol- Wherein the abrasive particles are at least one selected from the group consisting of abrasive particles.
The method according to claim 1, wherein the abrasive has a particle size of 2,000 mesh or more.
The method of claim 1, wherein the wet etching is performed by immersing the window substrate in an etching solution containing a fluorine compound, or spraying the etching solution onto a cutting surface.
8. The method of claim 7, wherein the etchant comprises 4 to 12% by weight of a fluorinated compound.
The method according to claim 7, wherein the temperature of the etchant is 15 to 40 占 폚.
The method of claim 1, wherein the wet etching is performed for 20 seconds to 10 minutes.