JP6549906B2 - Method of manufacturing glass substrate, and apparatus for manufacturing glass substrate - Google Patents

Description

  The present invention relates to a method of manufacturing a glass substrate and an apparatus for manufacturing a glass substrate.

  A flat glass plate is used as a component of a display unit of a display such as a liquid crystal display device or a plasma display device. In the following description, such a glass plate is referred to as a glass substrate for flat panel display, or simply as a glass substrate. For example, in a liquid crystal display device, a moving image can be displayed by changing the electric field applied to the liquid crystal sealed between the glass substrates and changing the alignment of the liquid crystal. Since it is necessary to change the electric field at the time of displaying an image of the liquid crystal display device, a transparent electrode for applying a voltage is formed on the glass substrate.

  In addition, in a liquid crystal display device used for a television receiver or the like that requires high quality display to control on / off of a voltage applied to an electrode on a glass substrate, an active matrix using thin film transistors (TFTs) Control of the scheme is adopted. This TFT is also formed on the glass substrate. Specifically, in a liquid crystal display, a TFT (Thin Film Transistor) for controlling the transmission amount of light, a liquid crystal, and a color filter are components. In a method of manufacturing a color filter panel in a liquid crystal display, usually, a black matrix is formed on the surface of a glass substrate, and then different hues of red, green and blue are sequentially formed in a stripe or mosaic color pattern Methods are used.

  As the definition of displays increases, the line width and pitch of the black matrix disposed on the surface of the glass substrate decrease. For example, in order to achieve high contrast of the display, improvement of the aperture ratio by high fine line and high definition of the black matrix (specifically, line width less than 20 μm) and high dimensional accuracy of the black matrix It is necessary to improve the light shielding property. Also, as the display pixel density increases, the pattern size varies depending on the application of the color filter and each color, but as an example, red, green and blue pixels are 200 to 300 μm to 100 μm, and the black matrix is 20 μm Thin line technology has been developed from 10 μm to 5 μm.

  As described above, since an electrode or an active element is formed by a very thin metal film or semiconductor on the glass surface of a glass substrate for flat panel display, the glass surface of the glass substrate has extremely high flatness and extremely high cleanliness. Sex is required.

  By the way, if the glass substrate for flat panel displays is a thing used for a liquid crystal display (henceforth a glass substrate for liquid crystals), for example, it will exhibit thin rectangular plate-like form. The thickness of a glass substrate for liquid crystal is generally thinner than about 0.05 mm to about 0.7 mm, and the demand for an increase in size is increasing year by year.

  The liquid crystal glass substrate is supplied to the manufacturing process of the liquid crystal display device in a form called mother glass having a size corresponding to a size of a plurality of glass substrates of a size necessary for one liquid crystal display device. The size of this mother glass is conventionally expressed by the term “generation”, and for example, the size of the sixth generation mother glass is 1500 mm × 1850 mm. The mother glass is obtained by cutting a glass plate formed into a plate shape into a predetermined size. And in order to remove dirt, chips, etc. which arose at the time of a cutting of a glass board, cleaning of a glass substrate for liquid crystals which is mother glass is needed.

  In the conveyance at the time of washing | cleaning of the glass surface of the glass substrate for liquid crystals performed in such a condition, the conveyance system using the roller for conveyance is used widely. As an example of the conveyance method using the conveyance roller, the method described in patent document 1 is proposed, for example. With regard to the cleaning of the glass substrate transported by such a transport method, the glass substrate is cleaned by physical cleaning, and the glass substrate is cleaned by a cleaning unit that applies a striking force to the glass.

JP, 2008-285243, A

  However, in the conventional glass transport method, as the thickness of the glass substrate becomes thinner, the influence of the deflection of the glass substrate becomes greater, and the glass substrate is intruded under the transport roller when the transport roller shifts. was there. In particular, as the thickness of the glass substrate becomes thinner, the bending phenomenon becomes remarkable, and when the thickness of the glass substrate is 0.4 mm (mm) or less, the distance between the commonly used conveying rollers is In order to increase the possibility of problems in conveyance, measures have been taken such as reducing the distance between the conveyance rollers. If the distance between the transfer rollers is narrow, even thin glass substrates can be stably transported, but the location where the cleaning unit for cleaning the glass substrates can be limited, so the height required for the glass substrates is high. There is a possibility that the cleaning ability can not be secured.

  Then, an object of this invention is to provide the manufacturing method of the glass substrate which can make stable conveyance of a glass substrate, and washability make compatible, and a manufacturing apparatus of a glass substrate.

One aspect of the present invention is a method for producing a glass substrate,
A conveying step of conveying the glass substrate horizontally by a plurality of rollers supporting a lower surface of the glass substrate for liquid crystal display;
And cleaning the lower surface of the glass substrate by bringing a brush unit of a cleaning unit arranged at a plurality of positions along the conveyance direction of the glass substrate into contact with the lower surface of the glass substrate being transported ;
In the transfer step, a plurality of locations along the transfer direction between the rollers on the upstream side and the downstream side of the transfer direction of the glass substrate among the plurality of rollers such that the glass substrate is horizontal , and A predetermined pressure is applied to the lower surface of the glass substrate by ejecting a fluid from a plurality of blow holes arranged at a plurality of locations along a width direction orthogonal to the transport direction, and the predetermined pressure and the plurality of to support the glass substrate by a roller,
It is characterized by

Another aspect of the present invention is a method for producing a glass substrate, comprising:
A conveying step of supporting the lower surface of the glass substrate for liquid crystal display and conveying the glass substrate horizontally;
And cleaning the lower surface of the glass substrate by bringing a brush unit of a cleaning unit arranged at a plurality of positions along the conveyance direction of the glass substrate into contact with the lower surface of the glass substrate being transported;
In the transfer step, the plurality of blows are arranged at a plurality of locations along the transfer direction of the glass substrate and a plurality of locations along the width direction orthogonal to the transfer direction so that the glass substrate is horizontal. By causing gas to be ejected from a hole and further aspirating the ejected gas, a predetermined pressure is applied to the lower surface of the glass substrate by the cleaning unit, and the glass substrate is floated and supported.
Wherein in the cleaning step removes foreign matter removed by the cleaning from the glass substrate by the suction,
It is characterized by

  It is preferable that the predetermined pressure is stronger as the roller moves away from the position at which the lower surface of the glass substrate is supported.

  It is preferable that the plate thickness of the said glass substrate is 0.4 mm or less.

Plurality another aspect of the present invention includes a plurality of rollers for supporting the lower surface of the glass substrate for a liquid crystal display, a substrate floating units for floating to convey the glass substrate, along the conveying direction of the glass substrate A cleaning unit that cleans the lower surface of the glass substrate by bringing a brush unit disposed at the position of the lower surface of the glass substrate into contact with the lower surface of the glass substrate being transported ;
The substrate floating unit includes a plurality of locations along the transport direction between the rollers on the upstream side and the downstream side of the transport direction of the glass substrate among the plurality of rollers such that the glass substrate is horizontal, and A predetermined pressure is applied to the lower surface of the glass substrate by ejecting fluid from a plurality of blow holes arranged at a plurality of locations along a width direction orthogonal to the transport direction, and the predetermined pressure and the plurality Supporting the glass substrate by the roller of
It is characterized by
Further, according to still another aspect of the present invention, there is provided a substrate floating unit that floats to transport a glass substrate for a liquid crystal display, and a brush unit disposed at a plurality of positions along the transport direction of the glass substrate. And a cleaning unit for cleaning the lower surface of the glass substrate by bringing it into contact with the lower surface of the glass substrate being transported.
The substrate levitation unit is disposed at a plurality of locations along the transport direction of the glass substrate and a plurality of locations along the width direction orthogonal to the transport direction such that the glass substrate is horizontal. The glass substrate is floated and supported by applying a predetermined pressure to the lower surface of the glass substrate by causing the gas to be jetted from the blow hole and further suctioning the jetted gas, and the glass substrate is supported. During the cleaning, the foreign matter removed from the glass substrate by the cleaning is removed by the suction.
It is characterized by

  According to the present invention, stable transport and cleaning properties of a glass substrate can be compatible even with a thin glass substrate.

It is a flowchart for demonstrating the outline | summary of the manufacturing method of the glass substrate of this embodiment. It is the schematic of a sheet-fed washing | cleaning apparatus. It is a top view of a washing unit. It is a side view of a washing unit. It is the figure which showed the state which the glass sheet supported by the conveyance roller bent. It is a schematic diagram which shows the magnitude | size of the blowing pressure concerning a glass sheet which changes according to distance. It is the figure which classified the size of the blow pressure by a substrate floating unit. 5 is a side view of the cleaning unit according to Embodiment 2. FIG.

<Composition of glass sheet>
A glass sheet (glass substrate) is glass used for manufacture of flat panel displays (FPD), such as a liquid crystal display, for example. In this glass sheet, a color filter is formed by arranging a black matrix and RGB pixels, which are wavelength selection elements that transmit red (R), green (G), and blue (B) light, on the surface. Ru. The black matrix improves the display contrast by blocking light leakage of the backlight outside the RGB pixel area and preventing color mixing of adjacent RGB pixels. That is, the passing area of light in the color filter is determined by the shape and arrangement of the black matrix. The thickness of the glass sheet is, for example, 0.1 mm to 0.7 mm, and may be 0.4 mm or less. The size of the glass sheet is, for example, 680 mm × 880 mm (G4 size) or 2200 mm × 2500 mm (G8 size).

The glass sheet used for manufacturing FPD is preferably alkali-free glass or slightly alkali glass. When the glass sheet is alkali-free glass, the composition of the glass is, for example, SiO ₂ : 50% by mass to 70% by mass, Al ₂ O ₃ : 0% by mass to 25% by mass, B ₂ O ₃ : 1% by mass to 15 mass%, MgO: 0 mass% to 10 mass%, CaO: 0 mass% to 20 mass%, SrO: 0 mass% to 20 mass%, BaO: 0 mass% to 10 mass%. Here, the total content of MgO, CaO, SrO and BaO is 5% by mass to 30% by mass.

When the glass sheet is a slight alkali glass containing a trace amount of alkali metal, the composition of the glass further includes 0.1% by mass to 0.5% by mass of R ′ ₂ O, preferably 0.2% by mass. % to 0.5 wt% of R 'containing ₂ O. Here, R ′ is at least one selected from Li, Na and K. Incidentally, the sum of the R _'2 O content may be less than 0.1 wt%.

Further, the glass sheet, in addition to the above _components, SnO 2: 0.01 wt% to 1 wt% (preferably 0.01 mass% to 0.5 _{mass%), Fe 2 O 3:} 0 wt% It may further contain 0.2% by mass (preferably 0.01% by mass to 0.08% by mass), and it is possible to substantially contain As ₂ O ₃ , Sb ₂ O ₃ and PbO in consideration of environmental load. It does not have to be contained in

<Flow of glass sheet manufacturing method>
FIG. 1 is a flow chart showing a flow of a method of manufacturing a glass sheet. Hereinafter, steps S1 to S10 of the flowchart will be described.

  First, in step S1, molten glass is produced by heating a glass material prepared to produce a glass sheet having the above-mentioned composition, and the molten glass or preform glass is produced by a downdraw method, a redraw method, a float method or the like. A glass ribbon having a predetermined thickness is continuously formed. In step S2, the glass ribbon produced | generated by step S1 is cut | disconnected, and the uncoated glass which has a predetermined | prescribed size is obtained. In step S3, the blank glass obtained in step S2 is placed on a pallet for conveying and storing blank glass as a laminated body laminated via an interleaf to protect the surface of the blank glass. .

  Next, in step S4, the sheet glass is taken out from the laminate of the sheet glass, and the sheet glass is cut into the size of the glass sheet which is a product. In step S5, the glass sheet obtained in step S4 is subjected to end face processing such as grinding and polishing of the end face, and etching of the end face.

  Next, in step S6, the glass sheet is washed while being conveyed. In the cleaning step of the glass sheet, cullet, dust, dirt, sticky foreign matter and the like which are small pieces of glass attached to the surface of the glass sheet are removed. Further, in the cleaning process of the glass sheet, an inorganic alkaline cleaner containing a surfactant is used so that these foreign substances do not adhere again to the surface of the cleaned glass sheet.

  Next, in step S7, an optical inspection of the glass sheet cleaned in step S6 is performed. In step S8, the glass sheets that have passed the inspection in step S7 are placed on a pallet and packaged as a laminated body alternately stacked with interleaving paper for protecting the surface of the glass sheet. In step S9, the packed stack of glass sheets is shipped to the delivery destination of the FPD manufacturer. Pulp paper not containing recycled paper is used from the viewpoint of preventing foreign matter originating in the interleaving paper from adhering to the surface of the glass sheet as the interleaving paper sandwiched by the laminated body of the glass sheet to be shipped.

  Moreover, the laminated body of the uncoated sheet glass mounted on the pallet in step S3 may be stored for a long period of several weeks or several months in step S10. In this case, recycled paper is used as the interleaf inserted in the laminate of raw sheet glass to be stored, from the viewpoint of cost and environmental protection. As described above, the laminate of raw sheet glass stored for a long time is shipped in step S9 through the cutting process of step S4 to the packing process of step S8. In addition, the laminated body of the glass sheet mounted and packed in the pallet in step S8 may be stored over a long period of several weeks or several months in step S10.

<Flow of glass sheet cleaning process>
Next, the details of the glass sheet cleaning process performed in step S6 of FIG. 1 will be described. In the cleaning step of the glass sheet, for example, the surface of the glass sheet is cleaned using an inorganic alkaline cleaning agent to which a surfactant is added.

  In the cleaning step, the surface of the glass sheet is cleaned using, for example, an inorganic alkaline cleaning agent to which a surfactant is added. An inorganic alkaline cleaning agent is produced by adding an alkaline component to a diluted solution obtained by diluting a commercially available cleaning solution for glass sheet with water. For example, a PK-LCG series or a semi-clean series is used as the cleaning liquid for glass sheet. More specifically, a washing solution to which p-alkylsulfonic acid is added as a surfactant is used. p-alkylsulfonic acid is a nonionic surfactant (nonionic surfactant) and is a glass sheet compared to other anionic surfactants (anionic surfactant), eg, 1,3-alkylsulfonic acid Peeling of the black matrix can be suppressed even if it remains on the surface of the black matrix. Although nonionic surfactants do not exhibit ionicity even when dissolved in water, they are surfactants exhibiting surface activity, and therefore, when forming a black matrix on the surface of a glass sheet, the repulsion by ions is suppressed Therefore, the adhesion of the black matrix is good and the cleaning performance is excellent. The glass sheet cleaning solution is diluted with water, for example, to a concentration of 1 wt% to 5 wt%. The concentration of the alkali component of the diluted solution is, for example, 0.02 wt% to 0.15 wt% in terms of the concentration of potassium hydroxide (KOH). Water for diluting the cleaning agent is pure water or deionized water treated with ion exchange treatment, EDI (Electrodeionization) treatment, reverse osmosis membrane (RO membrane), and decarbonation gas treatment through a carbon dioxide removal apparatus. Ultrapure water is preferred in order to keep the surface of the glass sheet clean. Further, in order to remove the soluble organic matter, it is preferable to carry out a process of passing water through activated carbon. Specifically, foreign substances such as fine particles are removed from water using a filter, then water is passed through activated carbon to remove organic substances, and then ion exchange treatment, EDI treatment, filter treatment with reverse osmosis membrane, And, it is preferable to carry out decarbonation treatment through a carbon dioxide removal apparatus. In the ion exchange treatment, ionic substances contained in water, for example, chlorine ions, sodium ions and the like are removed from water using an ion exchange resin membrane. In the EDI process, an ion exchange resin membrane is used, and a potential gradient formed by applying a potential to an electrode is used to remove an ionic substance from water with high accuracy. In the reverse osmosis membrane filtration, ionic substances, salts and organic substances are removed from water. In carbon dioxide treatment, carbon dioxide gas is removed from water using a carbon dioxide removal apparatus.

In the present embodiment, KOH, NaOH, ETDA-4 is used as the dilution liquid for the glass sheet cleaning liquid.
1 selected from the group consisting of Na, ETDA-4K, Na4P2O7 and K4P2O7
A species or more alkaline component is added to produce the cleaning agent used in the cleaning step. The concentration of the alkali component of the cleaning agent is 1 wt% or more in terms of the concentration of potassium hydroxide (KOH). The above-mentioned alkali component has high etching property to glass and is excellent in solubility as compared with other alkali components. In particular, it is preferable to use KOH alone as an alkali component from the viewpoint of etching property, solubility, and an adverse effect on a thin film transistor formed in a glass sheet. Also, KOH and NaOH are advantageous in wastewater treatment as compared to other alkaline components.

  In addition, the cleaning agent used at a washing | cleaning process is strong in the cleaning power which removes a foreign material from a glass sheet, so that the density | concentration of an alkali component is high. However, if the concentration of the alkali component is too high, the apparatus for cleaning the glass sheet may be corroded to cause problems such as the formation of crystals in the cleaning agent. Therefore, it is preferable that the concentration of the alkaline component of the cleaning agent does not exceed 10 wt%. Further, in order to facilitate the handling of the cleaning agent, it is more preferable that the concentration of the alkaline component of the cleaning agent does not exceed 5 wt%.

  In the present embodiment, the glass sheet cleaning method includes two types of cleaning methods: single wafer cleaning and batch cleaning. Here, a method of cleaning a glass sheet by single wafer cleaning will be described. FIG. 2 is a schematic view of a single-wafer washing apparatus 1 of a glass sheet G for single-wafer washing. The single wafer cleaning apparatus 1 includes a cleaning unit 10 that performs a cleaning process. The glass sheet G is cleaned in the cleaning unit 10 with an inorganic alkaline cleaner added with a surfactant.

  FIG. 3 is a top view of the cleaning unit 10. FIG. 4 is a side view of the cleaning unit 10. The cleaning unit 10 is provided with the conveyance roller 11, the board | substrate floating unit 12, and the brush unit 13 as FIG.3 and FIG.4 shows.

  The transport roller (transport unit) 11 has a plurality of rollers, and transports the glass sheet G by the plurality of rollers. Each transport roller 11 rotates at the same speed in the same direction around the central axis. Moreover, each conveyance roller 11 is arrange | positioned so that a central axis may be located in a line on the same horizontal plane, and has the same diameter. The conveyance roller 11 is provided in the vicinity of both end portions of the glass sheet G so that the glass sheet G is not scratched or soiled by the contact of the portion to be the product of the glass sheet G and the conveyance roller 11. An external force in the surface direction is applied to the glass sheet G by the rotation of the conveyance roller 11 on the glass sheet G that is in contact with the conveyance roller 11, and the glass sheet G is smoothly conveyed horizontally at the same speed. The force applied to the glass sheet G differs between the supported position where the glass sheet G contacts the transport roller 11 and the unsupported position where the glass sheet G does not contact, and a thin glass sheet G (for example, having a thickness of 0.4 mm) In the following cases, the glass sheet G may be bent. Therefore, the force applied to the glass sheet G can be dispersed and the deflection of the glass sheet G can be suppressed by narrowing the distance between the conveyance rollers 11 disposed from the upstream side to the downstream side, respectively. If the space between the two is narrowed, the space for installing the brush unit 13 can not be secured. Therefore, by causing the glass sheet G to float by the substrate floating unit 12, the force that the glass sheet G receives by coming into contact with the transport roller 11 is dispersed, and the glass sheet G is suppressed from being bent. As shown in FIG. 3 and FIG. 4, by setting the distance between the respective conveying rollers 11 to, for example, 70 to 120 mm or more, a brush unit is provided between the upstream conveying roller 11 and the downstream conveying roller 11. 13 can be provided.

  The substrate floating unit 12 is a unit that applies a predetermined pressure (blow pressure) to the lower surface of the horizontal glass sheet G so that the force applied to the glass sheet G becomes uniform. Here, the blow pressure refers to the pressure applied to the glass sheet G by supplying air, a gas such as nitrogen, compressed air, or a liquid such as water or a cleaning liquid to one surface of the glass sheet G. The substrate floating unit 12 mainly includes a plurality of panels for supplying gas and liquid. The substrate floating unit 12 jets a gas or liquid from the blow holes 12 a so as to control the blow pressure applied to the lower surface of the glass sheet G so that the bending of the glass sheet G is suppressed. The substrate levitation unit 12 sets a regulator (not shown) provided for each blow hole 12a to a predetermined pressure, and applies compressed gas etc. for a predetermined time so that a predetermined blow pressure is applied to the lower surface of the glass sheet G. The blow pressure is controlled by spouting only. The blow pressure can be arbitrarily adjusted by adjusting the opening of the regulator, setting the pressure, jetting time, and the like. FIG. 5 is a view showing a state in which the glass sheet G supported by the transport roller 11 is bent. When the thickness of the glass sheet G is thin and the distance between the conveyance rollers 11 is wide, the glass sheet G is bent downward at a position where the glass sheet G is not supported by the conveyance roller 11 as shown in the figure. There is a risk of For this reason, the substrate floating unit 12 applies a blow pressure to the lower surface of the glass sheet G so as to suppress the bending of the glass sheet G. The bending of the glass sheet G becomes larger as it goes away from the position Gt in contact with the conveying roller 11, and the bending becomes maximum at the position Gf most distant from the contact position Gt with the conveying roller 11. The substrate floating unit 12 controls so that the bending of the glass sheet G is suppressed by maximizing the blow pressure at the position Gf and minimizing the blow pressure at the position Gt. As the difference between the height (distance) Hgt from the substrate floating unit 12 to the lower surface of the glass sheet G at the position Gt and the height (distance) Hgf from the substrate floating unit 12 to the lower surface of the glass sheet G at the position Gf is larger When the deflection of the sheet G is large and the difference is 0, that is, the height Hgt and the height Hgf are equal, the deflection of the glass sheet G is suppressed. Therefore, the blow pressure P is controlled so that the height Hgt and the height Hgf become equal. The blow pressure P (blow pressure applied to the glass sheet G) of the substrate floating unit 12 is, for example, based on the equation P = aD + b (where D: distance from position Gt, a: pressure change coefficient, b: initial value) It is determined. The substrate floating unit 12 controls the blow pressure of the initial value b at D = 0, that is, at the position Gt, and the blow pressure becomes stronger as the distance D becomes larger, that is, the position moves away from the position Gt. At the position Gf farthest from the position Gt, the blow pressure is controlled to be maximum. Thus, by applying a blowing pressure to the lower surface of the glass sheet G, it is possible to suppress the bending of the glass sheet G.

  FIG. 6 is a schematic view showing the magnitude of the blow pressure P applied to the glass sheet G which changes in accordance with the distance D from the position Gt. In the figure, the larger the circle of the blow pressure P, the stronger the blow pressure. The amount of bending of the glass sheet G increases as it is separated from the position supported by the conveyance roller 11. Therefore, as shown in the figure, the blow pressure P is weaker the closer to the position Gt and the blow pressure the closer to the position Gf. P is strong. The substrate floating unit 12 can suppress the bending of the glass sheet G by controlling the blow pressure in accordance with the distance from the contact position of the glass sheet G and the conveyance roller 11.

  Since the size of the substrate floating unit 12 and the distance between the upstream conveyance roller 11 and the downstream conveyance roller 11 are predetermined by design, the distance between each position Gt and the distance from each position Gt to the position Gf are It has been decided in advance. The substrate floating unit 12 controls the blow pressure so that the glass sheet G becomes flat based on the distance between each position Gt, the distance from each position Gt to the position Gf, and the thickness of the glass sheet G. FIG. 7 is a diagram in which the magnitude of the blow pressure by the substrate floating unit 12 is classified. The substrate floating unit 12 controls the amount of gas ejected from the blow holes 12a in the range F1, the range F2, and the range F3, respectively, so that the magnitude of the blow pressure in each range satisfies the range F1 <the range F2. The blow pressure is controlled to be in the range F3. As a result, the blow pressure increases in the range F3 where the amount of deflection of the glass sheet G is largest, and the blow pressure decreases in the range F1 where the amount of deflection of the glass sheet G is the smallest. .

  The brush unit 13 has a cleaning brush roll for cleaning the glass sheet G, and one or more are arranged along the transport direction of the glass sheet G. The brush unit 13 is an optional contact type unit that removes foreign substances, cleaning liquid and the like attached to the glass sheet G by contacting the glass sheet G. The brush units 13 are disposed in a pair (upper and / or lower) above and below the glass sheet G so that both surfaces of the glass sheet G to be conveyed can be cleaned. In addition, the brush units 13 are disposed to cross the conveyance direction of the glass sheet G, respectively. A plurality of cleaning brushes are attached to the outer peripheral surface of the cleaning brush roll. By the axial rotation of the cleaning brush roll, the cleaning brush contacts the surface of the conveyed glass sheet G to clean the surface of the glass sheet G. When only the both ends of the glass sheet G are supported by the conveyance roller 11, the glass sheet G is bent. In particular, when the glass sheet G becomes thin, the deflection becomes remarkable. When the arrangement interval of the conveyance rollers 11 is narrowed, the amount of bending of the glass sheet G decreases, but in order to suppress the bending of the glass sheet G having a thickness of 0.4 mm or less, It is necessary to narrow and adjoin, and in the state where conveyance roller 11 adjoins, brush unit 13 can not be provided between conveyance rollers 11, and cleaning of glass sheet G may be affected. When the glass sheet G is brought into contact with the brush unit 13 in a bent state, the contact pressure may be too strong, and the glass sheet G may be damaged by the brush unit 13. For this reason, it is necessary to support the glass sheet G by the transport roller 11 to suppress the bending of the glass sheet G while securing the cleaning property of the glass sheet G. In the present embodiment, the entire lower surface of the glass sheet G is supported by the blow pressure, so by providing the brush unit 13 between the transport rollers 11, even if there is a distance between the transport rollers 11, the glass Deflection of the sheet G is suppressed. Moreover, since the bending of the glass sheet G is suppressed, the both surfaces of the glass sheet G become horizontal, and the glass sheet G and the brush unit 13 contact uniformly, the glass sheet G is damaged by the contact with the brush unit 13 Since the glass sheet G is cleaned with an appropriate contact pressure, the cleaning power of the glass sheet G is improved.

  Further, the substrate floating unit 12 improves the cleaning power of the cleaning unit 10 by injecting the cleaning liquid while injecting the gas from the blow holes 12 a. A cleaning solution is supplied to the surface of the glass sheet G, and the glass sheet G is cleaned by the brush unit 13 while the glass sheet G is floated and conveyed by the blowing pressure. In addition to the support by the conveyance roller 11, the entire lower surface is supported by the blowing pressure, so that the glass sheet G is suppressed from being bent and is further cleaned by the cleaning liquid. The cleaning performance can be excellent because the cleaning liquid and the brush unit 13 can perform cleaning while stably transporting without bending.

  The cleaned glass sheet G is conveyed downstream by the cleaning unit 10, and a removal process is performed to remove the cleaning liquid attached to the glass sheet G. In this removal step, the cleaning liquid is removed using a cleaning unit having the same configuration as the cleaning unit 10 described above. The cleaning unit 10 used in the removing step supplies pure water or ultrapure water instead of the cleaning solution to float the glass sheet G. The cleaning unit 10 floats the glass sheet G with pure water or the like to remove the cleaning liquid attached to the surface of the glass sheet G with pure water while stably transporting the glass sheet G. The conveying method of the glass sheet G and the cleaning method are the same as in the cleaning step.

  The glass sheet G from which the cleaning solution has been removed is conveyed downstream, and a drying step is performed to remove (dry) the pure water adhering to the glass sheet G. The glass sheet G can be dried by using a known method such as a roller provided with a sponge that absorbs water, an air jet apparatus that blows air (gas) to blow water, and the like. The washing step of step 6 is a washing step of washing the glass sheet G with small pieces of cullet, dust, dirt, sticky foreign matter, etc., which are attached to the surface of the glass sheet G, using a washing liquid, and the glass sheet G. The cleaning solution is removed using pure water, and the drying process is performed to dry and remove the pure water adhering to the glass sheet G. After these steps, the inspection process of step 7 is performed. .

  In the above, the washing | cleaning method of the glass sheet by single wafer washing was demonstrated. By such conveyance and cleaning, since the glass sheet can be stably conveyed and cleaned, stable conveyance and cleaning property of the glass sheet can be compatible. In addition, since the glass sheet is floated by gas and conveyed, even a thin glass sheet, for example, a glass sheet having a thickness of 0.4 mm or less can be conveyed without bending the glass sheet. In addition, since the brush unit for cleaning the glass sheet can be provided between the upstream conveyance roller and the downstream conveyance roller without bending the glass sheet, the cleaning property of the glass sheet can be secured.

Second Embodiment
Next, a method of floating and conveying the glass sheet G by the substrate floating unit 12 without using the conveyance roller 11 will be described. In addition, description is abbreviate | omitted about the structure which is common in the above-mentioned embodiment.

  FIG. 8 is a top view of the cleaning unit according to the present embodiment. As shown in the figure, the cleaning unit 10 according to the present embodiment includes a substrate floating unit 12, a brush unit 13, and a transport unit 14.

The substrate floating unit 12 is provided with a suction hole 12 b for suctioning the gas and liquid ejected from the blow hole 12 a in addition to the blow hole 12 a for ejecting gas and liquid. The suction hole 12b is provided adjacent to the blow hole 12a. The substrate floating unit 12 individually controls the blow pressure applied to the glass sheet G by the gas or the like ejected from the blow holes 12 a and the suction pressure for suctioning the gas or the like from the suction holes 12 b.
The transport unit 14 grips one end of the glass sheet G and transports the glass sheet G while pulling the glass sheet G so as to advance the glass sheet G from the upstream side toward the downstream side. The glass sheet G is conveyed by the conveyance unit 14 pulling the glass sheet G in a state where the glass sheet G is floated by the substrate levitation unit 12.

  Next, a method of conveying the glass sheet G will be described. First, the substrate floating unit 12 jets gas from the blow holes 12 a to balance the buoyancy given to the glass sheet G by the gas injection and the gravity of the glass sheet G, and floats the glass sheet G to be horizontal. Let The substrate floating unit 12 applies a substantially uniform blow pressure to the entire lower surface of the glass sheet G by uniformly injecting the gas from the respective blow holes 12 a, thereby causing the glass sheet G to float. Next, the substrate floating unit 12 sucks the gas injected from the blow hole 12 a from the suction hole 12 b. The glass sheet G floats by the gas injection, but the balance between the buoyancy and the gravity may be lost due to the gas flow, and the horizontality of the glass sheet G may not be maintained due to the turbulence of the air flow. Therefore, the substrate floating unit 12 sucks the injected gas from the suction holes 12b, so that the air flow can be adjusted, and the glass sheet G can be raised while being kept horizontal. Further, by making the suction pressure suctioned by the suction holes 12b substantially uniform over the entire lower surface of the glass sheet G, the balance between the blow pressure and the suction pressure is maintained, and the glass sheet G is floated while being kept horizontal. Can. Next, the transport unit 14 grips one end of the glass sheet G that has floated horizontally and transports the glass sheet G by pulling in the downstream direction. The balance between the blow pressure and the suction pressure is maintained, and in a state where the glass sheet G floats, the glass sheet G can be conveyed while being horizontal by pulling the glass sheet G. Next, the brush unit 13 cleans the conveyed glass sheet G. Although the foreign matter adhering to the glass sheet G is removed by washing, there is a possibility that the removed foreign matter may adhere again to the glass sheet G depending on the gas flow. In the present embodiment, since the gas is sucked from the suction holes 12b of the substrate floating unit 12, the foreign matter removed by the washing is sucked together with the gas from the suction holes 12b, so the cleaning property of the glass sheet G is maintained. Thereafter, the glass sheet G is conveyed downstream, and a drying step of removing (drying) the pure water adhering to the glass sheet G is performed.

  In the above, the conveyance method of the glass sheet by single wafer washing | cleaning and the washing | cleaning method were demonstrated. By such conveyance and cleaning, since the glass sheet can be stably conveyed and cleaned, stable conveyance and cleaning property of the glass sheet can be compatible. In order to float and convey a glass sheet, even a thin glass sheet, for example, a glass sheet having a thickness of 0.4 mm or less, can be conveyed without bending the glass sheet. In addition, by cleaning and removing foreign substances adhering to the glass sheet from the suction holes, the cleaning property of the glass sheet can be maintained.

  The glass sheet (glass substrate) manufactured by this embodiment is suitable as a glass substrate for flat panel displays, for example, a glass substrate for liquid crystal displays, or a glass substrate for organic EL displays. Furthermore, the glass substrate manufactured in the present embodiment is particularly suitable as a glass substrate for LTPS (Low-temperature poly silicon) TFT display used for high definition display, or as a glass substrate for oxide semiconductor TFT display .

  As mentioned above, although the manufacturing method of a glass substrate of the present invention and the manufacturing device of a glass substrate were explained in detail, the present invention is not limited to the above-mentioned embodiment, example, etc., in the range which does not deviate from the main point of the present invention Of course, it may be improved or changed.

DESCRIPTION OF SYMBOLS 1 cleaning apparatus 10 cleaning unit 11 conveyance roller 12 board | substrate floating unit 13 brush unit 14 conveyance unit G glass sheet L liquid

Claims (6)

A conveying step of conveying the glass substrate horizontally by a plurality of rollers supporting a lower surface of the glass substrate for liquid crystal display;
And cleaning the lower surface of the glass substrate by bringing a brush unit of a cleaning unit arranged at a plurality of positions along the conveyance direction of the glass substrate into contact with the lower surface of the glass substrate being transported;
In the transfer step, a plurality of locations along the transfer direction between the rollers on the upstream side and the downstream side of the transfer direction of the glass substrate among the plurality of rollers such that the glass substrate is horizontal, and A predetermined pressure is applied to the lower surface of the glass substrate by ejecting a fluid from a plurality of blow holes arranged at a plurality of locations along a width direction orthogonal to the transport direction, and the predetermined pressure and the plurality of Supporting the glass substrate by a roller and
The manufacturing method of the glass substrate characterized by the above. A conveying step of supporting the lower surface of the glass substrate for liquid crystal display and conveying the glass substrate horizontally;
And cleaning the lower surface of the glass substrate by bringing a brush unit of a cleaning unit arranged at a plurality of positions along the conveyance direction of the glass substrate into contact with the lower surface of the glass substrate being transported;
In the transfer step, the plurality of blows are arranged at a plurality of locations along the transfer direction of the glass substrate and a plurality of locations along the width direction orthogonal to the transfer direction so that the glass substrate is horizontal. By causing gas to be ejected from a hole and further aspirating the ejected gas, a predetermined pressure is applied to the lower surface of the glass substrate by the cleaning unit, and the glass substrate is floated and supported.
In the cleaning step, foreign matter removed from the glass substrate by the cleaning is removed by the suction.
The manufacturing method of the glass substrate characterized by the above. The predetermined pressure is stronger as the roller moves away from the position where the roller supports the lower surface of the glass substrate.
The method of manufacturing a glass substrate according to claim 1 , The thickness of the glass substrate is 0.4 mm or less.
Process for producing a glass substrate according to any one of claims 1 3, characterized in that. A plurality of rollers supporting a lower surface of a glass substrate for a liquid crystal display; a substrate floating unit which floats to transport the glass substrate; and a brush unit disposed at a plurality of positions along the transport direction of the glass substrate. And a cleaning unit for cleaning the lower surface of the glass substrate by bringing the lower surface of the glass substrate into contact with the lower surface of the glass substrate during transport.
The substrate floating unit includes a plurality of locations along the transport direction between the rollers on the upstream side and the downstream side of the transport direction of the glass substrate among the plurality of rollers such that the glass substrate is horizontal, and A predetermined pressure is applied to the lower surface of the glass substrate by ejecting fluid from a plurality of blow holes arranged at a plurality of locations along a width direction orthogonal to the transport direction, and the predetermined pressure and the plurality Supporting the glass substrate by the roller of
An apparatus for manufacturing a glass substrate characterized by A substrate floating unit for floating to transport a glass substrate for liquid crystal display, a brush unit arranged at a plurality of positions along the transport direction of the glass substrate, and a lower surface of the glass substrate being transported; And a cleaning unit for cleaning the lower surface of the glass substrate by bringing the glass substrate into contact with the substrate.
The substrate levitation unit is disposed at a plurality of locations along the transport direction of the glass substrate and a plurality of locations along the width direction orthogonal to the transport direction such that the glass substrate is horizontal. The glass substrate is floated and supported by applying a predetermined pressure to the lower surface of the glass substrate by causing the gas to be jetted from the blow hole and further suctioning the jetted gas, and the glass substrate is supported. During the cleaning, the foreign matter removed from the glass substrate by the cleaning is removed by the suction.
An apparatus for manufacturing a glass substrate characterized by

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