JP2013014465A - Glass substrate for flat panel display and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass substrate for a flat panel display, which can prevent breakage from occurring in a flat panel display manufacturing process, and to provide a method for manufacturing the glass substrate.SOLUTION: The glass substrate for a flat panel display has first and second principal surfaces opposite to each other in the thickness direction and has a lubricant adhering only to the second principal surface. The lubricant is disposed to lie, between the second principal surface and a conveyance member which conveys the glass substrate for a flat panel display, when the glass substrate for a flat panel display is conveyed in a flat panel display manufacturing process.

Description

  The present invention relates to a glass substrate for a flat panel display and a manufacturing method thereof.

  For the production of flat panel displays such as liquid crystal displays and plasma displays, a thin glass substrate having a thickness of, for example, 0.1 to 1.5 mm is used. In recent years, the flat panel display has been increased in size, and accordingly, for example, a glass substrate having a size of 2200 mm × 2500 mm is used.

  In such a glass substrate, a laminated body formed by laminating a large number of glass substrates is accommodated in a packaging device and conveyed to a delivery destination at a time. At the delivery destination, a semiconductor element or the like is formed on the glass substrate by forming a Si thin film or the like on the glass substrate.

  In general, when transporting glass substrates, the surface of the glass substrate is prevented from being scratched by contact between adjacent glass substrates, thereby stabilizing the plurality of glass substrates in the flat panel display manufacturing process. And the production efficiency of the flat panel display can be improved. In order to prevent the surface of the glass substrate from being damaged, a protective sheet such as a protective paper or a protective film is sandwiched between the glass substrates.

  In addition, another method has been proposed for preventing the surface of the glass substrate from being damaged when the glass substrate is conveyed to a delivery destination (Patent Document 1). In this method, a paper or film containing a lubricant for protecting the surface of the glass substrate is pressed against the surface of the glass substrate, and the lubricant is transferred to the surface of the glass substrate. The lubricant transferred to the surface of the glass substrate suppresses the surface of the glass substrate from being damaged when the adjacent glass substrates come into contact with each other when the plurality of glass substrates are conveyed.

JP 2011-46586 A

  By the way, regarding the method for preventing the surface of the glass substrate from being damaged when being transported to the delivery destination, in addition to the technique described in the above-mentioned patent document, various ideas have been made. There is no known method for preventing the glass substrate from being damaged when the manufacturing process of the flat panel display is carried out. For example, in the technique described in Patent Document 1, the lubricant transferred to the glass substrate is easily removed in the cleaning process. Therefore, after the cleaning process, for example, a transport member such as a transport roller or a push-up pin is used. When the glass substrate is used and conveyed, the conveying member directly contacts the glass substrate, so that the glass substrate may be damaged and the glass substrate may be broken.

  Then, an object of this invention is to provide the glass substrate for flat panel displays which can prevent that a breakage arises in the manufacturing process of a flat panel display, and its manufacturing method.

One embodiment of the present invention is a glass substrate for a flat panel display having first and second main surfaces opposed to each other in the plate thickness direction and having a lubricant attached only to the second main surface. The flat panel display glass substrate is
The lubricant is interposed between the second main surface and a conveying member that conveys the flat panel display glass substrate when the flat panel display glass substrate is conveyed in the manufacturing process of the flat panel display. To be provided.

It is preferable that the lubricant is attached to a region in contact with the conveying member in the region of the second main surface.
Moreover, it is preferable that a member made of a water-insoluble material formed in a shape of a region in contact with the conveying member in the region of the second main surface is provided so as to cover the lubricant.

Another aspect of the present invention is a method for producing a glass substrate for a flat panel display, which has first and second main surfaces opposed to each other in the plate thickness direction, and having a lubricant attached only to the second main surface. . The manufacturing method is
When the flat panel display glass substrate is transported in the flat panel display manufacturing process, the lubricant is interposed between the second main surface and a transport member that transports the flat panel display glass substrate. An adhesion process for adhering.
Moreover, it is preferable to include the shaping | molding process which shape | molds a glass ribbon using the overflow downdraw method, and the plate-making process which obtains a glass substrate by plate-making the glass ribbon after a shaping | molding process.

  According to the glass substrate for flat panel displays of the said aspect and its manufacturing method, it can prevent that a breakage arises in the manufacturing process of a flat panel display.

It is a disassembled perspective view of the packing apparatus which accommodates the glass substrate of this embodiment. It is a figure which shows an example of the flow of the manufacturing method of a glass substrate. It is a principal part expansion perspective view of the 2nd main surface of a glass substrate. It is a figure explaining the glass substrate to which the lubricant was adhered. (A) is a figure which shows the mounting state of the glass substrate in the mounting surface of an adsorption | suction table, (b) is a figure which shows a state when a glass substrate leaves | separates from the adsorption | suction table. It is a figure explaining the adhesion aspect of a lubricant. It is a figure explaining an example of the adhesion method of a lubricant. It is a figure explaining an example of the adhesion method of a lubricant. It is a figure explaining arrangement | positioning of a glass substrate and protective paper. It is a figure explaining arrangement | positioning with a glass substrate and a protective sheet.

  Hereinafter, the glass substrate for flat panel displays of the present invention (hereinafter referred to as a glass substrate) and the manufacturing method thereof will be described.

FIG. 1 is a diagram showing a packaging device 100 that houses the glass substrate 20 of the present embodiment.
The packing apparatus 100 is an apparatus used for packing a laminated body 10 formed by laminating a plurality of glass substrates 20 in the plate thickness direction.
The packing apparatus 100 includes a support base 110 and a container housing 120. The support base 110 supports and fixes the laminated body 10. The container housing 120 covers the stacked body 10 fixed to the support base 110 together with the support base 110. The configuration of the packaging device is not limited to the above.
A plurality of glass substrates 20 constituting layered product 10 are used for manufacture of flat panel displays, such as a liquid crystal display, a plasma display, and an organic EL (Electro-Luminescence) display, for example.

(Schematic description of glass substrate)
Hereinafter, an outline of the glass substrate 20 will be described.
The thickness of the glass substrate 20 is 0.1 to 1.5 mm, and the upper limit value of the preferable thickness is 1.1 mm, 0.7 mm, and 0.5 mm, and the most preferable upper limit value is 0.4 mm. . Here, the thinner the glass substrate 20 is, the lower the strength of the glass substrate 20 itself is. Therefore, in the manufacturing process of the flat panel display, when the glass substrate 20 is transported in a state where the thickness direction of the glass substrate 20 is along the vertical direction, for example, when the thickness of the glass substrate 20 is 0.5 mm or less As will be described later, the problem of breakage of the glass substrate 20 becomes significant.
Therefore, a lubricant 30 (see FIG. 4) is attached to the glass substrate 20 of the present embodiment, as will be described later. By attaching the lubricant 30 to the glass substrate 20, even if the thickness of the glass substrate 20 is 0.5 mm or less, the remarkable effect of preventing the glass substrate 20 from being broken during the conveyance of the glass substrate 20. Have On the other hand, the lower limit of the preferred thickness is 0.2 mm.

Moreover, the size of the glass substrate 20 is 500-2500 mm x 2500-3500 mm (short direction length x long direction length). In addition, since the weight of the glass substrate 20 increases as the size of the glass substrate 20 increases, when the glass substrate 20 is transported in a state in which the thickness direction of the glass substrate 20 is along the vertical direction in the flat panel display manufacturing process. In addition, the problem that the glass substrate 20 is broken due to its own weight becomes significant. This problem 20 becomes significant when the length of the glass substrate in the short direction exceeds 2000 mm.
On the other hand, in the glass substrate 20 of the present embodiment, since the lubricant is adhered, the glass substrate 20 is transported when the glass substrate 20 is transported even when the length in the short direction of the glass substrate 20 is 2000 mm or more, particularly 2500 mm or more. It has a remarkable effect of preventing 20 breakage.

  Examples of the glass substrate 20 include borosilicate glass, aluminosilicate glass, aluminoborosilicate glass, soda lime glass, alkali silicate glass, alkali aluminosilicate glass, and alkali aluminogermanate glass. In addition, as a glass substrate for liquid crystal displays and a glass substrate for organic EL displays, it is preferable to apply a glass substrate that contains substantially no alkali or contains only a very small amount of alkali.

  The glass substrate 20 of the present embodiment is for a liquid crystal display, and has a first main surface 22 and a second main surface 24 that face each other in the plate thickness direction as shown in FIG. The first main surface 22 is a smooth surface on which a thin film such as a semiconductor element array or a color filter used in a liquid crystal display is formed, and the second main surface 24 is a smooth surface on which a polarizing filter is formed. is there. Further, a lubricant 30 (see FIG. 4) described later is attached to the second main surface 24 before the polarizing filter is formed.

The glass substrate 20 has a composition shown below, for example. The numerical value described in the following parenthesis is a preferable composition ratio. In the following composition ratios,% means mass%.
_{SiO 2: 50~70% (57~64%} ),
_{Al 2 O 3: 5~25% (} 12~18%),
_{B 2 O 3: 0~15% (} 6~13%).
In addition, you may include arbitrarily the composition shown below.
MgO: 0 to 10% (0.5 to 4%),
CaO: 0 to 20% (3 to 7%),
SrO: 0 to 20% (0.5 to 8%, more preferably 3 to 7%),
BaO: 0 to 10% (0 to 3%, more preferably 0 to 1%),
ZrO ₂ : 0 to 10% (0 to 4%, more preferably 0 to 1%).
Further, among the above compositions, in _{particular, SiO 2: 50~70%, B} 2 O 3: 5~18%, Al 2 O 3: 10~25%, MgO: 0~10%, CaO: 0~20 %, SrO: 0 to 20%, BaO: 0 to 10%, RO: 5 to 20% (wherein R is at least one selected from Mg, Ca, Sr and Ba).
Furthermore, it is more preferable that R ′ ₂ O: more than 0.20% and 2.0% or less (provided that R ′ is at least one selected from Li, Na, and K).
Furthermore, it is preferable that 0.05 to 1.5% of the refining agent is contained in total, and As ₂ O ₃ , Sb ₂ O ₃ and PbO are not substantially contained. This is because As ₂ O ₃ , Sb ₂ O ₃ and PbO are substances having an effect of clarifying glass, but are substances having a large environmental load. Here, “substantially not contained” means that the mass% is less than 0.01% and is not intentionally contained except for impurities.
Moreover, it is preferable that content of the iron oxide in glass is 0.01 to 0.2%.

(Each component)
SiO ₂ is a component constituting the glass skeleton of the glass substrate, and has the effect of increasing the chemical durability and heat resistance of the glass. If the content of SiO ₂ is too low, the effects of chemical durability and heat resistance cannot be obtained sufficiently, and if the content of SiO ₂ is too high, the glass tends to be devitrified, making molding difficult. At the same time, the viscosity increases and it becomes difficult to homogenize the glass.

Al ₂ O ₃ is a component that forms a glass skeleton, and has an effect of increasing the chemical durability and heat resistance of the glass. Al ₂ O ₃ also has the effect of increasing the glass etching rate. When the content of Al ₂ O ₃ is too low, the effects of chemical durability and heat resistance of the glass cannot be obtained sufficiently. On the other hand, when the content ratio of Al ₂ O ₃ is too high, the viscosity of the glass increases to make it difficult to dissolve, and the acid resistance decreases.

B ₂ O ₃ is a component that lowers the viscosity of the glass and promotes melting and clarification of the glass. If the content of B ₂ O ₃ is too low, the acid resistance of the glass is lowered, so that it is difficult to homogenize the glass.

  MgO and CaO are components that lower the viscosity of the glass and promote glass melting and fining. Further, Mg and Ca are advantageous components for improving the meltability while reducing the weight of the obtained glass because the ratio of increasing the density of the glass is small in the alkaline earth metal. However, when the content rate of MgO and CaO becomes too high, the chemical durability of glass will fall.

  SrO and BaO are components that lower the viscosity of the glass and promote glass melting and fining. Moreover, it is also a component which improves the oxidizability of a glass raw material and improves clarity. However, if the content of SrO and BaO becomes too high, the density of the glass increases, the weight of the glass plate cannot be reduced, and the chemical durability of the glass decreases.

K ₂ O is a component that lowers the high-temperature viscosity of the glass and improves the meltability and moldability of the glass and at the same time improves the devitrification resistance. If the content of K ₂ O is too low, the melting property of the glass is lowered, so that the cost for the glass melting step is increased. Moreover, since the devitrification resistance of the glass is lowered and the glass is easily devitrified, it is difficult to use the downdraw method in the glass forming step described later. On the other hand, if the content of K ₂ O is too high, devitrification resistance is lowered due to deterioration of the glass balance, making it difficult to use the downdraw method.

K ₂ O is a component that elutes from the glass and degrades TFT (Thin Film Transistor) characteristics of the semiconductor device. Therefore, when it is applied as a glass substrate for a liquid crystal display device, it is not preferable to contain K ₂ O in a large amount. . Specifically, the content of K ₂ O is preferably set to 2.0% or less, for example. However, by deliberately containing a specific amount of the above components in the glass, the basicity of the glass is increased and the oxidation of the metal whose valence fluctuates is increased while suppressing deterioration of TFT characteristics and thermal expansion of the glass within a certain range. It is possible to make it clear and exhibit clarity.

ZrO ₂ is a component that increases the viscosity and strain point near the devitrification temperature of glass. ZrO ₂ is also a component that improves the heat resistance of the glass. However, if the content of ZrO ₂ is too high, the devitrification temperature of the glass increases and the devitrification resistance of the glass decreases.

  Moreover, you may add a clarifier to glass as a component which defoams the bubble in glass. The fining agent component is not particularly limited as long as it has a low environmental burden and is excellent in glass fining. Examples of the fining agent include at least one of metal oxides such as tin oxide, iron oxide, cerium oxide, terbium oxide, molybdenum oxide, and tungsten oxide.

(Glass substrate manufacturing method)
FIG. 2 is a diagram for explaining an example of the flow of the method for manufacturing the glass substrate 20. The manufacturing method of the glass substrate 20 of this embodiment is a melting process (step S10), a clarification process (step S20), a stirring process (step S30), a shaping | molding process (step S40), and a slow cooling process (step S50). ), Plate-making process (step S60), shape processing process (step S70), polishing process (step S80), cleaning process (step S90), inspection process (step S100), and adhesion process (step S110). ) And a packing process (step S120).

  In the melting step (step S10), in a melting furnace (not shown), the glass raw material is heated by indirect heating by combustion of fossil fuel and direct heating by electric conduction to produce molten glass. The melting of the glass may be performed by other methods.

  Next, a clarification process is performed (step S20). In the clarification step, bubbles in the molten glass are removed using the above-described clarifier while the molten glass is stored in a liquid tank (not shown). Specifically, it is performed by a redox reaction of a metal oxide whose valence fluctuates in molten glass. In the molten glass at a high temperature, the metal oxide releases oxygen by a reduction reaction, and this oxygen becomes a gas, and bubbles in the molten glass grow and float on the liquid surface. Thereby, bubbles in the molten glass are defoamed. Or the bubble of oxygen gas takes in the gas in the other bubble in a molten glass, grows, and floats on the liquid level of a molten glass. Thereby, bubbles in the molten glass are defoamed.

  Next, a stirring process is performed (step S30). In the stirring step, the molten glass is passed through a vertically-shown stirring tank (not shown) in order to maintain the chemical and thermal uniformity of the glass. The molten glass moves to the bottom in the vertical downward direction while being stirred by a stirrer provided in the stirring tank, and is led to a subsequent process. Thereby, nonuniformity of the glass such as striae can be suppressed.

  Next, a molding process is performed (step S40). In the forming step, a slot down draw method, an overflow down draw method, a float method, a redraw method, or the like is used as a method for forming the glass substrate 20. The down draw method including overflow down draw, slot down draw, and the like is a known method described in, for example, Japanese Patent Application Laid-Open No. 2010-189220, Japanese Patent No. 3586142, and the like. Thereby, a sheet-like glass ribbon having a predetermined thickness and width is formed. As a molding method, it is preferable to use a downdraw method, particularly an overflow downdraw method. This is because, in the overflow downdraw method, the surface of the glass ribbon is formed without contact with the molded body, so that contamination of the surface of the glass ribbon due to contact with the molded body can be prevented, and the surface quality is good. This is because a simple glass ribbon can be formed. Therefore, it is useful to use the overflow downdraw method because a glass ribbon having a good surface quality can be formed, thereby omitting the polishing step described later, and as a result, the manufacturing cost of the glass substrate can be reduced. .

Next, a slow cooling process is performed (step S50). Specifically, the glass ribbon is cooled below the annealing point in an annealing furnace (not shown) by controlling the cooling rate so as not to cause distortion.
Next, a plate-making process is performed (step S60). Specifically, a glass substrate is obtained by continuously collecting glass ribbons that are produced at regular intervals.

  Next, a shape processing process is performed (step S70). In the shape processing step, the glass substrate 20 having a predetermined size and shape is cut out. For the shape processing, physical means using sandblasting, a cutter or a laser may be used, or chemical means such as etching may be used.

Next, a polishing process is performed (step S80). In the polishing step, the surface and end surface of the glass substrate 20 are ground and polished. In the polishing process, for example, a diamond wheel or a resin wheel is used.
In the polishing step, as shown in FIG. 3, chamfered portions 24 a formed by chamfering are provided at at least one of the four corners of the second main surface 24 of each of the plurality of glass substrates 20. FIG. 3 is an enlarged perspective view of a main part of the second main surface 24 of the glass substrate 20. The chamfered portion 24a is an example of a mark. By forming the chamfered portion 24 a only on the second main surface 24 of each of the plurality of glass substrates 20, the first main surface 22 and the second main surface 24 can be easily distinguished.
Note that the chamfered portion may be formed only on the second main surface 24 of the glass substrate 20 or only on the first main surface 22. Further, notches, chamfered portions, and the like serving as marks may be formed at the ends of the four sides of the first main surface 22 or the second main surface 24. Further, a sticker, a stamp, or the like may be added as a mark.

  Thereafter, a cleaning process is performed (step S90). In the cleaning process, the abrasive and impurities adhering to the surface and the end face of the glass substrate 20 in the polishing process are removed by cleaning using, for example, ultrasonic waves or chemicals.

  Next, an inspection process is performed (step S100). In the inspection process, the frequency of occurrence of defects due to bubbles in the glass substrate 20 is examined, and the glass substrate 20 after the cleaning process is examined to determine whether or not the frequency of occurrence is a predetermined frequency or less.

Next, an adhesion process is performed (step S110). In the attaching step, as shown in FIG. 4, the lubricant 30 having a low water solubility is attached only to the second main surface 24 of the glass substrate 20. FIG. 4 is a view for explaining the glass substrate to which the lubricant 30 is attached.
Here, the reason why the lubricant 30 with low water solubility is used is to prevent the lubricant 30 from being easily removed even when the glass substrate 20 is washed with water in the manufacturing process of the liquid crystal display.

The reason why the lubricant 30 is attached only to the second main surface 24 is to prevent a problem that occurs in the manufacturing process of the liquid crystal display when the lubricant 30 adheres to the first main surface 22. Specifically, for example, when a semiconductor element array is formed on the first main surface 22 to which the lubricant 30 is adhered, the adhesion of the metal thin film deposited on the first main surface 22 deteriorates. Thus, the metal thin film may be peeled off from the first main surface 22. Further, when a color filter is formed on the first main surface 22 to which the lubricant 30 is adhered, the adhesion of the black matrix for the color filter to the first main surface 22 becomes too high, and the black matrix pattern It becomes difficult to form.
In order to prevent these problems from occurring, a complicated process of removing the lubricant 30 from the first main surface 22 is necessary before the process of forming the semiconductor array or the color filter. Therefore, in the present embodiment, by attaching the lubricant 30 only to the second main surface 24 of the glass substrate 20, the above problem can be prevented and the lubricant 30 is removed from the first main surface 22. The process can be omitted.

  Furthermore, when the glass substrate 20 is conveyed in the manufacturing process of the liquid crystal display, the lubricant 30 conveys the glass substrate 20 with the second main surface 24 and the thickness direction of the glass substrate 20 along the vertical direction. It is preferable to be provided so as to be interposed between the conveying member (for example, a conveying roller and a push-up pin). Specifically, it is preferable that the lubricant 30 adheres at least to a region in contact with the conveying member in the region of the second main surface 24. This is to prevent the glass substrate 20 from being scratched and the glass substrate 20 from being broken by the conveyance member being in direct contact with the second main surface 24 of the glass substrate 20.

  For example, when the semiconductor element array or the color filter is formed on the first main surface 22, the second main surface 24 is attracted to the mounting surface of the suction table 200 as shown in FIG. As a result, the glass substrate 20 is placed on the suction table 200. After the semiconductor element array or the color filter is formed on the first main surface 22, the glass substrate 20 moves upward while being supported by the push-up pins 202 protruding upward from the mounting surface of the suction table 200. Accordingly, the suction table 200 is separated. Here, when the lubricant 30 is not attached to the second main surface 24, the second main surface 24 may be damaged by receiving an impact directly when the push-up pin 202 contacts the glass substrate 20. There is. Moreover, when the glass substrate 20 with a thin plate thickness is used, since the strength of the glass substrate 20 is reduced, the glass substrate 20 may be broken by the impact.

In the present embodiment, as shown in FIG. 5B, the lubricant 30 is attached to a region of the second main surface 24 that contacts the push-up pin 202, so that the second main surface 24 is pushed up. The impact received from the pin 202 can be reduced by the lubricant 30. Thereby, it is possible to prevent the second main surface 24 from being damaged by the impact received from the push-up pin 202.
Further, since the lubricant 30 is attached to the second main surface 24, the second main surface 24 does not directly contact the suction table 200. For this reason, it is possible to prevent the second main surface 24 from being damaged by contacting the suction table 200.
Furthermore, even when glass fragments are attached to the conveyance roller that conveys the glass substrate 20, the glass fragments come into contact with the glass substrate 20 when the glass substrate 20 is conveyed by the conveyance roller. 20 can be prevented from being damaged.

  In the manufacturing process of the liquid crystal display, when the polarizing film is formed on the second main surface 24, it is preferable that the lubricant 30 is removed from the second main surface 24. This is because, when the polarizing film is formed on the second main surface 24, if the lubricant 30 adheres to the second main surface 24, there arises a problem that the retardation film hardly adheres to the polarizing film.

Next, the type of lubricant 30 will be described.
The lubricant 30 is preferably an acid amide, particularly an acid amide of an organic compound. This is because acid amides do not have water solubility that is high enough to be easily removed by water. Thereby, for example, when the glass substrate 20 is washed with water before being conveyed by the conveying member, the lubricant 30 can be prevented from being easily removed from the second main surface 24 of the glass substrate 20. .

The lubricant 30 is preferably a fatty acid, particularly an unsaturated fatty acid. This is because the fatty acid has a lubricity effect, and thus it is possible to prevent the surface of the glass substrate 20 from being damaged by contact or friction between the adjacent glass substrates 20 in the laminate 10.
Furthermore, unsaturated fatty acids are more preferred because they have a lower melting temperature than saturated fatty acids. This is because when the lubricant 30 is melted and applied to the second main surface 24, if the melting temperature of the lubricant 30 is too high, the fatty acid crystallizes before the lubricant 30 is applied to the second main surface 24. This is because it becomes difficult to uniformly apply the lubricant 30 to the second main surface 24.

  Further, the lubricant 30 has 8 to 100 carbon atoms, preferably 10 to 50 carbon atoms, and most preferably 10 to 30 carbon atoms. This is because when the number of carbon atoms is too small, a sufficient lubricity effect cannot be obtained. Further, when the number of carbon atoms is too small, the water solubility of the lubricant 30 becomes high. Therefore, when the glass substrate 20 is washed with water before being transported by the transport member, the lubricant 30 becomes the second main surface 24. May be easily removed from On the other hand, when the carbon number is too high, the melting temperature of the lubricant 30 becomes high, so that the fatty acid crystallizes before the lubricant 30 is applied to the second main surface 24, and the lubricant 30 This is because it becomes difficult to uniformly coat the surface 24.

From these viewpoints, it is preferable to use a fatty acid amide, particularly an unsaturated fatty acid amide, as the lubricant 30. Here, as the unsaturated fatty acid amide, oleic acid amide, erucic acid amide, stearic acid amide, behenic acid amide, palmitoleic acid amide, vaccenic acid amide, linoleic acid amide, linolenic acid amide, arachidonic acid amide, nervonic acid amide, etc. Is mentioned. In this embodiment, erucic acid amide is used as the lubricant 30.
Further, in the manufacturing process of the liquid crystal display, even if the glass substrate 20 is washed with water before the start of the manufacturing process, in order to prevent all of the lubricant 30 from being removed, the mass% in the lubricant 30 is 10%. It is preferable to use the lubricant 30 containing -100 mass% erucic acid amide.
In addition, the amount of erucic acid amide per unit area of the second main surface 24 is 1 ng to 1 mg / cm ² , preferably 10 ng to 500 ng / cm ² , more preferably 20 ng to 200 ng / cm ² . If the amount of erucic acid amide per unit area is too small, it is difficult to achieve the effect of preventing the glass substrate 20 from being broken or scratched. On the other hand, if the amount of erucic amide per unit area is too large, the erucic amide may aggregate and peel from the glass substrate 20. The peeled erucic acid amide may cause a problem that occurs in the manufacturing process of the liquid crystal display.

In the attaching step, the lubricant 30 may be attached to the entire surface of the second main surface 24, or as shown in FIG. 6, the lubricant 30 may be attached to a region in contact with the conveying member. For example, when the lubricant 30 is attached to the region of the second main surface 24 that contacts the push-up pin 202, the lubricant 30 is formed on the second main surface 24 as shown in FIG. Within a range that is less than or equal to the dimension of the second major surface 24 in the lateral direction from each of the four corners (for example, 10% or less, 20% or less, 40% or less of the dimension of the second major surface 24 in the lateral direction) It may be attached to the region, or as shown in FIG. 6 (b), it is attached to the region within the range from the center of the four sides of the second main surface 24 to the dimension in the short direction of the second main surface 24. May be. Further, as shown in FIGS. 6C to 6E, for example, the lubricant 30 formed in a circular shape having a diameter equal to or smaller than the dimension of the second main surface 24 in the short direction is used as the second main surface. You may adhere to the vicinity of the four corners of 24, the vicinity of the center of the four sides of the second main surface 24, or the center of the second main surface 24. Note that the lubricant 30 may be formed in a polygonal shape.
Further, in the case where the lubricant 30 is attached to a region in contact with the conveyance roller in the region of the second main surface 24, the second main surface 24 extends in the short direction of the second main surface 24 as shown in FIG. The lubricant 30 may be attached in a plurality of straight lines. Alternatively, the lubricant 30 may be attached in a plurality of straight lines extending in the longitudinal direction of the second main surface 24. Further, the lubricant 30 may be attached on the second main surface 24 in a lattice shape.
Further, in the manufacturing process of the liquid crystal display, even if the glass substrate 20 is washed with water before the start of the manufacturing process, in order to prevent all of the lubricant 30 from being removed, the lubricant 30 is used as the second main component. It is preferable to adhere to the surface 24 thickly (for example, 1 nm to 2 mm in thickness).

Next, a method for attaching the lubricant 30 will be described.
When adhering the lubricant 30 to the second main surface 24 of the glass substrate 20, first, the lubricant 30 is melted, and the melted lubricant 30 is deposited or applied to the second main surface 24 of the glass substrate 20. Alternatively, the lubricant 30 may be adhered to the second main surface 24 by spraying the lubricant 30 dissolved in the solvent using a spray or the like. Here, as the solvent, for example, alcohols such as ethanol and isopropyl alcohol are preferably used.

Further, in the manufacturing process of the liquid crystal display, even if the glass substrate 20 is washed with water before the start of the manufacturing process, the method shown in FIG. May be used. FIG. 7 is a diagram for explaining an example of a method for attaching the lubricant 30.
First, as shown in FIG. 7A, the lubricant 30 is attached to the entire surface of the second main surface 24. Here, in the case where the region in contact with the conveying member is a region within a predetermined range (for example, 40% of the dimension in the short direction of the glass substrate 20) from each of the four corners of the second main surface 24, the region. A sheet S made of a water-insoluble resin formed in the shape of is attached so as to cover the region. Here, the sheet S is an example of a member made of a water-insoluble material. Thereafter, when the glass substrate 20 is washed with water in the manufacturing process of the liquid crystal display, depending on the cleaning time of the glass substrate 20, as shown in FIG. Removed. In this case, since the lubricant 30 adhering to the area is covered with the sheet S, it is possible to prevent the lubricant 30 adhering to the area from being completely removed by washing. Then, after the glass substrate 20 is cleaned, the sheet S is removed as shown in FIG. In this way, even when the glass substrate 20 is washed with water in the manufacturing process of the liquid crystal display, the lubricant 30 can remain in the region of the second main surface 24 in contact with the conveying member. it can.

FIG. 8 is a diagram illustrating another example of a method for attaching the lubricant 30.
As shown in FIG. 8A, the lubricant 30 is not attached to the second main surface 24. Here, in the case where the region in contact with the conveying member is a region within a predetermined range (for example, 40% of the dimension in the short direction of the glass substrate 20) from each of the four corners of the second main surface 24, the region. As shown in FIG. 8B, the protective film 50 formed in the shape is pasted so as to cover the region. Here, the protective film 50 is an example of a member made of a water-insoluble resin and made of a water-insoluble material. The lubricant 30 is attached to the surface of the protective film 50 that contacts the second main surface 24, and the protective film 50 is affixed to the second main surface 24, so that the lubricant 30 is the second main surface 24. It adheres to the main surface 24. Here, even if the glass substrate 20 is washed with water in the manufacturing process of the liquid crystal display, the protective film 50 can prevent the lubricant 30 from being completely removed. Then, after the glass substrate 20 is washed, the protective film 50 is removed as shown in FIG. In this way, the lubricant 30 can remain in the region of the second main surface 24 that contacts the conveying member.
Thus, the glass substrate 20 for liquid crystal displays of this embodiment is manufactured.

Next, a packing process is performed (step S120).
As shown in FIG. 9, the glass substrates 20 are conveyed one by one and placed on the support base 110, and are stacked in the plate thickness direction of the already placed glass substrate 20. When the glass substrate 20 is laminated, the protective paper 40 for protecting the surface of the glass substrate 20 is used as the second main surface 24 of the glass substrate 20 and the first of the other glass substrates 20 adjacent to the glass substrate 20. Between the main surface 22 and the main surface 22. By interposing the protective paper 20 in this way, the surface of the glass substrate 20 in the laminated body 10 is prevented from being damaged, and furthermore, the glass substrates 20 in the laminated body 10 are electrostatically intimately adhered to each other. Can be prevented. In addition, since the protective paper 40 is interposed between the glass substrates 20, the lubricant 30 attached to the second main surface 24 of the glass substrate 20 is in contact with the first main substrate of another glass substrate 20 adjacent to the glass substrate 20. Since it can prevent adhering to the surface 22, in the manufacturing process of a liquid crystal display, the complicated process of removing the lubricant 30 from the 1st main surface 22 can be skipped.
In addition, by interposing only the protective paper 40 between the glass substrates 20, the thickness dimension of the laminated body 10 including the protective paper 40 is reduced as compared with the thickness dimension of the laminated body 10 further including the protective film 50, for example. be able to. Therefore, since the number of the glass substrates 20 which can be accommodated in the packing apparatus 100 can be increased, many glass substrates 20 can be supplied to the manufacturing process of a liquid crystal display at once. Therefore, the manufacturing efficiency of a flat panel display such as a liquid crystal display can be improved.

Moreover, the glass substrate 20 is laminated | stacked on a plate | board thickness direction so that the 1st main surface 22 may face the same direction (A direction of FIG. 9). Thereby, for example, the first main surface 22 and the second main surface 24 of each of the plurality of glass substrates 20 of the laminate 10 can be easily discriminated at the delivery destination of the glass substrate 20. Therefore, since the main surfaces 22 and 24 of the glass substrate 20 are not erroneously discriminated in the manufacturing process of the liquid crystal display, the processing on the main surfaces 22 and 24 can be performed accurately. Therefore, the manufacturing efficiency of a flat panel display such as a liquid crystal display can be improved.
Further, since the chamfered portion 24a is formed at the end of the second main surface 24 of the glass substrate 20, the glass substrate 20 is arranged so that the chamfered portion 24a faces the same direction and is aligned in the plate thickness direction. By laminating, the glass substrate 20 can be easily laminated so that the first main surface 22 faces in the same direction.

In addition, as shown in FIG. 10, the protective film 50 may be stacked between the glass substrates 20. In this case, the protective film 50 is detachably sandwiched between the glass substrate 20 and the protective paper 40. Here, the lubricant 30 is attached to the surface of the protective film 50 that contacts the second main surface 24 of the glass substrate 20, and the protective film 50 and the glass substrate 20 are laminated to protect the surface. The lubricant 30 attached to the film 50 is transferred to the second main surface 24 of the glass substrate 20.
Thus, the protective film 50 for attaching the lubricant 30 to the second main surface 24 is interposed between the glass substrates 20, so that the lubricant 30 is easily attached to the second main surface 24 of the glass substrate 20. be able to.

  As described above, according to the glass substrate 20 of this embodiment, when the glass substrate 20 is transported in the manufacturing process of the liquid crystal display, the lubricant 30 is interposed between the second main surface 24 and the transport member. Since it is provided so as to be interposed, it is possible to prevent the conveying member from directly contacting the second main surface 24 of the glass substrate 20. Therefore, the conveyance member can prevent the glass substrate 20 from being scratched, and further, the glass substrate 20 from being broken, so that the glass substrate 20 can be prevented from being damaged in the manufacturing process of the liquid crystal display. . Thereby, the manufacturing efficiency of flat panel displays, such as a liquid crystal display, can be improved.

  As mentioned above, although the glass substrate for flat panel displays of the present invention and the manufacturing method thereof have been described in detail, the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the gist of the present invention. Of course.

DESCRIPTION OF SYMBOLS 10 Laminated body 20 Glass substrate 22 1st main surface 24 2nd main surface 24a Chamfering part 30 Lubricant 40 Protective paper 50 Protective film

Claims (5)

A glass substrate for a flat panel display having first and second main surfaces opposed to each other in the plate thickness direction, and having a lubricant attached only to the second main surface,
The lubricant is interposed between the second main surface and a transport member that transports the flat panel display glass substrate when the flat panel display glass substrate is transported in the manufacturing process of the flat panel display. To be provided,
A glass substrate for a flat panel display.   The glass substrate for a flat panel display according to claim 1, wherein the lubricant is attached to a region in contact with the conveying member in the region of the second main surface.   The flat panel according to claim 2, wherein a member made of a water-insoluble material formed in a shape of a region in contact with the conveying member in the region of the second main surface is provided so as to cover the lubricant. Glass substrate for display. A method for producing a glass substrate for a flat panel display having first and second main surfaces opposed to each other in the plate thickness direction and having a lubricant attached only to the second main surface,
When the flat panel display glass substrate is transported in the flat panel display manufacturing process, the lubricant is interposed between the second main surface and a transport member that transports the flat panel display glass substrate. Including an attachment process to attach,
The manufacturing method of the glass substrate for flat panel displays characterized by the above-mentioned. A molding process for molding a glass ribbon using the overflow downdraw method,
The manufacturing method of the glass substrate for flat panel displays of Claim 4 including the plate-making process of obtaining a glass substrate by plate-making the glass ribbon after a formation process.

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