JP2006027911A - Method for polishing surface of glass plate, glass substrate for flat panel display, and flat panel display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for polishing the surface of a glass plate to obtain the high flatness surface after polishing, and to provide a high flatness glass substrate for a flat panel display and the flat panel display. <P>SOLUTION: This method comprises dissolving and polishing a glass plate surface while including an aqueous hydrofluoric solution or hydrofluoric gas between a pad and the glass substrate. The glass substrate after polishing can be used for the flat panel display, and the display can be produced by using the glass substrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a method for polishing a glass plate, and in particular, a method for polishing a glass plate surface that can be suitably used for flattening the surface of a glass plate, a glass substrate for a flat panel display polished using this method, and this The present invention relates to a flat panel display using a glass substrate.

A liquid crystal display (LCD), a type of flat panel display, has a structure in which a pair of glass substrates on which one or more transparent electrodes are laminated on one surface is bonded, and production has been expanded as a thin image display device. ing. Even this thin LCD is aimed at further thinning, and Patent Document 1 discloses a method for thinning a glass substrate which is a component of the LCD.
Japanese Patent Laid-Open No. 4-116619

  The method of thinning the glass substrate disclosed in Patent Document 1 is to immerse the glass substrate in a polishing liquid to polish the surface of the glass substrate, thereby thinning the glass substrate. According to this method, it is described in Patent Document 1 that the glass substrate is uniformly polished over the entire surface and the entire glass substrate can be uniformly thinned.

  In the process of manufacturing a glass substrate, which is a constituent member of an LCD, or in the process of bonding a pair of glass substrates, the surface of the glass substrate may be damaged by contact with the outside. FIG. 4 is a diagram for explaining the surface shape change when a glass substrate having a damaged surface is immersed in a polishing liquid. FIG. 4A is a cross-sectional view showing the glass substrate 12 whose surface is damaged, and FIG. 4B is a diagram in which the glass substrate 12 of FIG. 4A is immersed in a polishing liquid and subjected to surface polishing. . As shown in FIG. 4B, when polishing is performed by immersing the surface of the glass substrate 12 having scratches 13 on the surface in a mere polishing liquid as described in Patent Document 1, Regardless of the presence or absence, the entire surface of the glass substrate 12 is polished, and the scratch 13 that is a recessed portion on the surface of the glass substrate is not completely eliminated, so that the glass substrate with poor surface flatness is obtained. There's a problem. The problem of becoming a glass substrate with poor surface flatness also occurs when a glass substrate used in a plasma display or electroluminescence display, which is the same flat panel display as an LCD, is immersed in an etching solution and polished. It will be.

  A flat panel display using a glass substrate with poor flatness as a constituent member of an image display surface is a flat panel display in which the displayed image is likely to be distorted. Therefore, it is desired to provide a method for polishing a glass substrate surface that can improve the flatness of the glass substrate surface.

  In view of the above circumstances, the present invention provides a method for polishing a glass plate surface having high flatness on the surface of the glass plate after polishing, even when the glass plate having scratches on the surface is polished. An object of the present invention is to provide a polished glass substrate for a flat panel display and a flat panel display using the glass substrate.

  The present invention is a method for polishing a glass plate surface by contacting a pad with the surface of the glass plate, wherein hydrogen fluoride is interposed between the pad and the glass plate surface. Polishing method. The hydrogen fluoride is preferably supplied as a hydrogen fluoride aqueous solution or hydrogen fluoride gas, and hydrogen fluoride is interposed between the pad and the glass plate.

  The present invention is the glass substrate for flat panel display polished by the polishing method. Moreover, this invention is a flat panel display using the said glass substrate.

  According to the polishing method configured as described above, when the sludge generated in the polishing process is filled into the recessed portion of the scratch, the glass surface other than the scratch is polished while suppressing subsequent polishing of the scratch surface. Therefore, the flatness of the glass plate surface after polishing becomes high.

  Moreover, the glass substrate for flat panel displays configured as described above becomes a glass substrate with high flatness, and the flat panel display configured as described above is a flat manufactured using a glass substrate with high flatness. Since it is a panel display, it becomes a flat panel display in which distortion of the displayed video is suppressed.

  The present invention will be described based on an embodiment. FIG. 1 is a diagram for explaining an apparatus for carrying out a method according to a first embodiment relating to the present invention. This apparatus holds a surface plate 3 to which a pad 2 is attached and is rotatable, a nozzle 4 for supplying an aqueous hydrogen fluoride solution to the surface of the pad 2 attached to the surface plate 3, and a glass substrate to be polished. And a glass substrate polishing head 1 which is brought into contact with the pad 2 and rotated in a pressed state. The glass substrate polishing head 1 includes a glass substrate holding holder 1a and a shaft 1b extending perpendicularly to the upper direction of the central axis of the holder 1a.

  The hydrogen fluoride aqueous solution is obtained by dissolving hydrogen fluoride having glass-soluble properties in water, but a compound other than hydrogen fluoride may be dissolved together with hydrogen fluoride. Fluorides such as ammonium fluoride, potassium fluoride and sodium fluoride, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid, organic acids such as acetic acid and succinic acid, anionic surfactants, amphoteric surfactants, etc. One or more surfactants may be selected and dissolved in an aqueous hydrogen fluoride solution.

  The method according to the present invention performed using the apparatus shown in FIG. 1 is performed as follows. After rotating the pad 2 together with the surface plate 3 with its central axis as the rotation axis, an aqueous hydrogen fluoride solution is supplied from the nozzle 4 to the surface of the pad 2 and fluorinated between the pad 2 and the glass substrate in contact with the surface. An aqueous hydrogen solution is interposed. Since the pad 2 is rotating, the hydrogen fluoride aqueous solution is supplied to the entire surface of the pad 2. The glass substrate held by the holder 1a of the polishing head 1 is brought into contact with the pad 2 and further pressed by rotating the glass substrate by rotating the shaft 1b. In this way, the method according to the first embodiment is used.

  FIG. 2 is a cross-sectional view for explaining a polishing method according to the present invention. In FIG. 2, the glass substrate 5 and the pad 2 are spaced apart from each other, but this is shown separated for convenience of explanation.

  In FIG. 2A, the surface of the glass substrate 1 on which the scratches 6 are present is directed to the pad 2 side and polished with a hydrogen fluoride aqueous solution (not shown) interposed between the glass substrate 5 and the pad 2. It is a figure. In the polishing process, hydrogen fluoride dissolves and polishes the surface of the glass substrate 5. Then, a slightly soluble sludge 7 is generated in the hydrogen fluoride aqueous solution, and this sludge 7 is interposed between the glass substrate 5 and the pad 2 together with the polishing liquid.

  FIG. 2B is a diagram in which polishing of the surface of the glass substrate 5 in FIG. Both the glass substrate 5 and the polishing pad 2 rotate in the same direction, and the sludge 7 is filled in the scratch 6 of the glass substrate 5 with this rotation. Further, the sludge 7 is prevented from adhering to a portion other than the scratch on the surface of the glass substrate 5 by friction between the pad 2 and the glass substrate 5.

  FIG. 2C is a diagram in which polishing of the surface of the glass substrate 5 in FIG. The sludge 7 filled in the scratches on the glass substrate 5 has a hardly soluble property with respect to the aqueous hydrogen fluoride solution, so that the polishing of the scratched portion of the glass substrate 5 is prevented from proceeding simultaneously with the polishing of other portions. The The sludge 7 is removed by the pad 2 at the same speed as the polishing speed of the portion other than the scratch on the glass substrate 5.

  FIG. 2D is a diagram in which polishing of the surface of the glass substrate 5 in FIG. By proceeding with the polishing, the scratch on the surface of the glass substrate 5 disappears. When polishing is stopped after the scratch has disappeared, a glass substrate with high flatness can be obtained. The aqueous hydrofluoric acid solution is removed by washing.

  When the glass substrate is polished by the method according to the first embodiment described above, the sludge generated by the reaction between the glass and the hydrogen fluoride aqueous solution is forcibly filled into the concave portion of the glass surface scratch, and the polishing of the concave portion is the other polishing. Progressing simultaneously with the polishing of the portion is prevented. That is, by delaying the polishing of the concave portion, the glass substrate surface other than the concave portion is polished in advance, and the sludge that is configured to form the same plane as the portion other than the concave portion by this preliminary polishing, It is removed by the pad at the same speed as the polishing speed of the portion other than the concave portion. As a result, the flatness of the polished glass substrate surface is improved. Further, since the pressure at the interface between the glass substrate and the hydrogen fluoride aqueous solution is increased by the polishing head 2, the polishing rate for dissolving and polishing the glass substrate surface is increased.

  Next, a method according to a second embodiment relating to the present invention will be described. FIG. 3 is a diagram for explaining an apparatus for carrying out the method according to the second embodiment of the present invention. 3A is a simplified perspective view of the apparatus, and FIG. 3B is a schematic cross-sectional view taken along the line AA in FIG. 3A. The apparatus of FIG. 3 includes a surface plate 9 to which a pad 8 is attached and which is rotatable, and a glass substrate polishing head 1 which holds a glass substrate 10 to be polished, abuts against the pad 8 and rotates in a pressed state. Prepare. The glass substrate polishing head 1 includes a glass substrate holding holder 1a and a shaft 1b extending perpendicularly to the upper direction of the central axis of the holder 1a.

  The pad 8 is made of a breathable porous resin, and the surface plate 9 is connected to a hydrogen fluoride gas supply pipe 11 for supplying hydrogen fluoride gas to the surface on which the pad 8 is bonded. The hydrogen fluoride gas supplied from the supply pipe 11 is jetted toward the glass substrate 1 through the pad 8, and hydrogen fluoride is interposed between the glass substrate 10 and the pad 8.

  When hydrogen fluoride gas is injected onto the glass substrate 10, the surface of the glass substrate 10 is dissolved and polished. During this polishing, sludge is generated as in the first embodiment. However, since the polishing is performed while rotating the surface plate 9 and the holder 1a of the polishing head 1 as in the first embodiment, sludge is generated. Will be filled in the scratches on the surface of the glass substrate 10 and this will prevent the scratched surface from being polished. That is, even when polishing is performed using hydrogen fluoride gas, the flatness of the surface of the glass substrate after polishing is high as in the first embodiment.

  In the first embodiment and the second embodiment, the polishing of the glass substrate has been described. However, this glass substrate can be used for polishing a glass substrate used for a flat panel display such as an LCD. Alternatively, the glass substrate may be a pair of glass substrates used for an LCD.

  The polishing method according to the present invention is capable of producing a glass substrate having high flatness required for a glass substrate used for a flat panel display. Therefore, the glass substrate polished by using the polishing method of the present invention. Is suitably used as a glass substrate for a flat panel display, and a flat panel display can be produced using this glass substrate.

It is a figure for demonstrating the apparatus for implementing the method which concerns on 1st embodiment regarding this invention. It is sectional drawing for demonstrating the grinding | polishing method which concerns on this invention. It is a figure for demonstrating the apparatus for enforcing the method which concerns on 2nd embodiment regarding this invention. It is a figure explaining the surface shape change when the glass substrate where the surface was damaged is immersed in polishing liquid.

Explanation of symbols

2 Pad 5 Glass substrate 6 Scratch 7 Sludge

Claims (5)

A method for polishing a surface of a glass plate by contacting a pad with the surface of the glass plate, wherein hydrogen fluoride is interposed between the pad and the surface of the glass plate. The polishing method according to claim 1, wherein the hydrogen fluoride is supplied as a hydrogen fluoride aqueous solution, and hydrogen fluoride is interposed between the pad and the glass plate. The polishing method according to claim 1, wherein the hydrogen fluoride is supplied as hydrogen fluoride gas, and hydrogen fluoride is interposed between the pad and the glass plate. The glass substrate for flat panel displays grind | polished by the method in any one of Claims 1-3. A flat panel display using the glass substrate according to claim 4.

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