JP2010188479A - Belt conveying and polishing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt conveying and polishing apparatus preventing any excessive polishing of a substrate end, uniformizing the surface of a workpiece, and enhancing the yield of products in a polishing machine for polishing a color filter in which a large number of products are assembled to a large glass substrate. <P>SOLUTION: The belt conveying and polishing apparatus comprises at least the polishing head of a compound structure of a rectangular rigid plate and the polishing pad of an elastic body arranged on its lower surface, a belt conveying mechanism for horizontally conveying a color filter (workpiece) to be polished in a loaded state on a belt with its color filter side upwardly, and a polishing mechanism oscillated while pressing the polishing pad against the surface of the horizontally conveyed workpiece. The belt conveying and polishing apparatus has a clearance adjusting means for setting the height of the polishing head to the conveying belt to the specified value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a belt conveyance polishing machine for a color filter used in a color liquid crystal display device, and is used for polishing removal and the like of protrusions and photoresist residues and aggregates caused by overlapping of a resin black matrix and colored pixels. The present invention relates to a belt conveying polishing machine.

  In general, a color liquid crystal display device is configured by enclosing a liquid crystal between a color filter substrate having a polarizing plate on the outside and an element substrate. A voltage is applied to each pixel between the color filter substrate and the element substrate side to control the transmission / non-transmission of light, and the transmitted light is displayed on the screen as display light.

  The color filter substrate includes a transparent glass substrate as a structural support, and the opposite side (back side) of the screen observer is divided into a large number of pixel regions, and the inter-pixel region located at the boundary between the pixel region and the pixel region. Is provided with a pattern of a light shielding layer (black matrix: hereinafter abbreviated as BM), and colored pixels are arranged in each of the pixel regions. The colored pixels color the transmitted light for each pixel, and generally, three colored pixels of red (R), green (G), and blue (B) corresponding to the three primary colors of light are arranged. The BM prevents the mixed color of transmitted light colored in these colors. Conventionally, a metal chromium film has been used, but in recent years, a photosensitive resin in which a black pigment such as carbon black is dispersed is used. It has become mainstream.

  When providing colored pixels at the black matrix opening in the display area, the end of the colored pixel runs over the end of the black matrix to avoid a gap (so-called white spot) between the black matrix and the colored pixel. It is common to have a structure, which becomes a protrusion. In this case, a step and a protrusion are generated in the colored pixel in the riding portion, and in particular, in a twisted nematic (TN) liquid crystal display device or a vertical alignment liquid crystal display device, light leakage due to liquid crystal alignment failure is a problem.

  Therefore, there is a method of separately providing a flattening layer (overcoat layer) after forming the colored pixels in order to fill the steps and protrusions due to the colored pixels. However, since this leads to an increase in process and cost, it is required to improve the flatness of the surface of the color filter without providing a flattening layer.

  In order to remove the protrusions on the surface of the color filter or reduce the height of the protrusions to such an extent that the alignment of the liquid crystal molecules is not affected, the surface of the color filter is conventionally polished. For example, a color filter is placed and fixed on a circular table of a flat plate polishing machine, and the polishing pad surface bonded to the surface plate is brought into pressure contact with the surface of the color filter to be polished (hereinafter referred to as a workpiece), There is a method of removing the protrusions on the surface of the color filter by rotating the circular table and swinging the circular platen while dropping the polishing liquid.

  However, if the polishing process for the color filter surface is on a separate line from the colored pixel forming process, the stoppage loss of the equipment due to the movement of the glass substrate occurs and the productivity of the polishing work is not good. In addition, with the recent increase in size of glass substrates with the spread of large-screen LCD TVs, the thickness of glass substrates that are as thin as 1 mm or less and one side of 1 m or more has increased, and the belt conveyance system that allows safer handling A polishing apparatus has been proposed. For example, in Patent Document 1, a color filter is transported horizontally, a polishing liquid supply unit supplies a polishing liquid to a color filter surface, and a polishing unit rotates a rectangular polishing head in contact with the color filter surface. A polishing method for flattening the color filter surface is disclosed.

  In addition to large LCD TVs, the application of color liquid crystal display devices to personal computers, various monitors and mobile devices is expanding rapidly, and it is used to polish color filters with many products on large glass substrates. As a result, the above-described belt-conveying type polishing apparatus is effective, but since the color filter (work) to be polished is increased in size to 1 to 2 m or more on one side, the surface of the work can be made uniform. It's getting harder. Conventional belt-conveying polishing machines perform polishing after pressing the polishing pad against the workpiece. In this case, pad surface sagging occurs between the polishing pad and the end of the workpiece, and the outer periphery of the workpiece is overpolished. Therefore, there are problems that the work surface is non-uniform and the product located at the edge of the substrate becomes defective. The demand for cost reduction of color filters, which account for a large percentage of the price structure of liquid crystal panels, has become strict, and improvement of the product yield in the polishing process is urgently needed.

JP 2005-288649 A

  The present invention has been made in view of the above-described problems, and in a polishing machine for polishing a color filter with a large number of products imposed on a large glass substrate, the substrate surface is prevented from being excessively polished. It is an object of the present invention to provide a belt conveying polishing apparatus capable of improving the uniformity of the product and improving the product yield.

  The invention according to claim 1 of the present invention has a polishing head having a composite structure of at least a rectangular rigid plate and an elastic polishing pad disposed on the lower surface thereof, and a color filter (work) surface to be polished facing upward. A belt transporting and polishing apparatus comprising: a belt transporting mechanism that transports horizontally while being placed on a belt; and a polishing mechanism that swings while pressing the polishing pad against the surface of the work being transported horizontally. A belt conveying polishing apparatus comprising a clearance adjusting means for setting a height of the polishing head with respect to a conveying belt to a specified value.

  According to a second aspect of the present invention, the clearance adjustment means moves vertically to the position outside the belt of the rigid plate of the polishing head simultaneously with the raising and lowering of the polishing head via a free bearing. The belt conveying polishing apparatus according to claim 1, wherein a support base having a specified height is installed.

  The invention according to claim 3 of the present invention is characterized in that, as the clearance adjusting means, a work receiving recess having the same depth as the height of the work is installed on the conveyor belt. This is a belt conveying polishing apparatus.

  The invention according to claim 4 of the present invention is characterized in that, as the clearance adjusting mechanism, a work receiving recess having the same depth as the height of the work is installed in the polishing pad. This is a belt conveying polishing apparatus.

According to the belt conveying and polishing apparatus of the present invention, since the clearance adjusting means for setting the height of the polishing head with respect to the conveying belt to a specified value is provided, it is possible to prevent the pad attached to the polishing head from sagging and It becomes possible to suppress overpolishing. As a result, the workpiece end and the workpiece center can be polished with equal uniformity. Due to the above effects, it is possible to use up to the end of the workpiece, and it is possible to increase the yield even when multiple products are taken from one workpiece.

The plane schematic diagram (a) which looked at an example of the belt conveyance polishing apparatus of this invention from the upper side, and the cross-sectional schematic diagram seen in the direction parallel to the advancing direction (b). Explanatory drawing which showed typically an example of the color filter (work | work) of grinding | polishing object in a cross section. A cross-sectional schematic view (a) of a polishing section of a conventional belt conveying polishing apparatus viewed in a direction perpendicular to the workpiece traveling direction, and the measurement result of in-plane variation of a laminated PS (photo spacer) of color filters polished by the apparatus. Explanatory drawing (b) shown. Sectional drawing (a) which looked at the grinding | polishing part of an example of the belt conveyance grinding | polishing apparatus which concerns on Claim 2 of this invention in the direction orthogonal to the workpiece advancing direction, and explanatory drawing which shows a part of side surface of a grinding | polishing part in a cross section (B). The cross-sectional schematic diagram which looked at the grinding | polishing part of the belt conveyance grinding | polishing apparatus of an example which concerns on Claim 3 of this invention in the direction orthogonal to the workpiece advancing direction. The cross-sectional schematic diagram which looked at the grinding | polishing part of the belt conveyance grinding | polishing apparatus of an example which concerns on Claim 4 of this invention in the direction orthogonal to the workpiece advancing direction.

  Hereinafter, a belt conveyance polishing apparatus of the present invention will be described based on an embodiment.

  FIG. 1 is a schematic plan view (a) of an example of the belt conveyance polishing apparatus of the present invention as viewed from above, and a schematic cross-sectional view (b) of the belt conveyance polishing apparatus as viewed in a direction parallel to the traveling direction. This belt conveyance polishing apparatus includes a polishing liquid supply unit (30) provided with a polishing liquid supply nozzle (14), and a conveyance belt (12) that holds and conveys the back surface of the glass substrate of the work (1) on the belt surface. ), A rectangular rigid plate (2) and an elastic polishing pad (3), and a polishing portion (20) provided with a polishing head (10) having a composite structure. The polishing head (10) is integrally connected to a rotating shaft (5) for rotating the polishing head at an upper portion thereof. The roller conveyor (13) and the conveyor belt (12) for horizontally conveying the color filter (work) (1) to be polished are shown in the drawing from the left front step (colored pixel forming step) to the right rear step ( To the water washing step), the polishing liquid supply unit (30) and the polishing unit (20) are provided. The lower surface plate (19) supports the polishing head (10) while holding a workpiece during polishing.

  The color filter (work) (1) to be polished is created in the colored pixel forming process of the previous process, and as shown in FIG. 2, red (R), green (G), blue ( As shown by dotted circles, each colored pixel layer in B) is in a surface state with protrusions and steps called horns. In FIG. 1, the workpiece (1) is conveyed by the roller conveyor (13) from the previous process on the left side while being fed by the polishing solution supply section (30), as shown by the white arrow. The polishing liquid is supplied from. Subsequently, the work (1) is transported by the transport belt (12) in the polishing section (20), while being held by the lower surface plate (19) and the transport belt (12), the polishing pad (3) is moved to the work (1 ) Is brought into contact with the surface and the polishing head (10) is rotated to flatten the color filter surface and conveyed to the right rear process (water washing process).

  The belt conveyance polishing apparatus of the present invention is intended for a work to be polished on a resin film, such as colored pixels formed on a glass substrate. Therefore, a polishing head having a composite structure of a rectangular rigid plate (2) and an elastic polishing pad (3) is used to polish the resin film, that is, a viscoelastic film. However, in the conventional belt conveyance polishing apparatus, the polishing is performed after pressing the polishing pad of the elastic body against the workpiece. In this case, it is difficult to adjust the clearance to set the height of the polishing head with respect to the conveyance belt to a specified value, As shown in FIG. 3 (a), the sagging of the polishing pad (11) occurs at the ends of the polishing pad (11) and the workpiece (1), and as shown in FIG. 3 (b), the outer peripheral portion of the workpiece. However, there is a problem that the surface of the workpiece becomes excessively polished, and the surface of the workpiece is not uniform and the product located at the edge of the substrate becomes defective.

  FIG. 4A is a schematic cross-sectional view of a polishing portion of an example of the belt conveyance polishing apparatus of the present invention as viewed in a direction perpendicular to the workpiece traveling direction. Here, as a clearance adjustment means for setting the height of the polishing head (10) with respect to the conveying belt (12) to a specified value, the rigid plate (2) of the polishing head (10) is positioned outside the conveying belt (12). As shown in FIG. 4 (b), a support base (16) having a specified height that is vertically moved simultaneously with the raising and lowering of the polishing head (10) through a free bearing (17) is installed. The free bearing (17) is installed on the support base (16) side in order to reduce the frictional force between the rigid plate (2) and the support base (16). Since this support base (16) needs to be vertically moved simultaneously with the raising and lowering of the polishing head (10), the support base and the polishing head are moved up and down using a ball screw (18). Since the position of the support base (16) is determined by the ball screw (18), it comes into contact but is not directly installed on the base (not shown) or the lower surface plate. Depending on the position, the height of the polishing head with respect to the conveying belt is set to a specified value, and the amount of pressing of the polishing pad with respect to the work is adjusted, so that uniform polishing within the surface becomes possible.

  FIG. 5 is a schematic cross-sectional view of a polishing portion of a belt conveyance polishing apparatus according to another example of the present invention, as viewed in a direction perpendicular to the workpiece traveling direction. Here, as a clearance adjusting means for setting the height of the polishing head (10) with respect to the conveyor belt (12) to a specified value, a workpiece accommodating recess having the same depth as the workpiece (1) is installed in the conveyor belt (12). Has been. The workpiece receiving recess is recessed by, for example, cutting a part of the belt (the part where the workpiece is placed), or by raising a part of both sides of the belt, the workpiece is put into the recess between the raised parts. The depth of the recess may be the same as the height of the workpiece, and when polishing, the polishing pad (3) of the elastic body is pushed into the workpiece for polishing. Even if it is the same, it will be in a shape where it indents by elastic deformation of polishing pad (3) itself when it pushes in. In this case, the surface of the polishing pad does not sag and uniform polishing within the surface is possible.

  Further, FIG. 6 is a schematic cross-sectional view of a polishing portion of a belt conveyance polishing apparatus of another example different from the above of the present invention as viewed in a direction perpendicular to the workpiece traveling direction. Here, as a clearance adjustment means for setting the height of the polishing head (10) with respect to the conveyor belt (12) to a specified value, the polishing pad (3) accommodates a workpiece having the same depth as the workpiece (1). A recess is installed. In this case, a groove is cut in the polishing pad (3) by the thickness of the work, and the work is polished at the cut portion. As a result, the polishing pad becomes thick at the end of the polishing pad, so that surface sagging can be prevented, and uniform polishing within the surface becomes possible.

  As described above, according to the belt conveyance polishing apparatus of the present invention, it is possible to suppress overpolishing of the workpiece end. As a result, the workpiece end and workpiece center can be polished with equal uniformity, and the yield can be increased even when multiple products are taken from one workpiece.

DESCRIPTION OF SYMBOLS 1 ... Color filter, workpiece | work 2 ... Rigid board 3 ... Polishing pad
5 ... Rotating shaft 10 ... Polishing head 11 ... Polishing pad
DESCRIPTION OF SYMBOLS 12 ... Conveyor belt 13 ... Roller conveyor 14 ... Polishing liquid supply nozzle 16 ... Support stand 17 ... Free bearing 18 ... Ball screw
19 ... Lower surface plate 20 ... Polishing part 30 ... Polishing liquid supply part
BM ... Black matrix
R ... Red pixel G ... Green pixel B ... Blue pixel

Claims (4)

A polishing head having a composite structure of at least a rectangular rigid plate and an elastic polishing pad disposed on the lower surface thereof;
Polishing that swings while pressing the polishing pad against the surface of the workpiece being horizontally conveyed, and a belt conveyance mechanism that conveys horizontally with the color filter (work) surface to be polished facing upward. In a belt conveyance type polishing apparatus comprising a mechanism,
A belt-conveying type polishing apparatus, comprising a clearance adjusting means for setting a height of the polishing head with respect to the conveying belt to a specified value.   As the clearance adjusting means, a support table having a specified height that is vertically moved simultaneously with the raising and lowering of the polishing head via a free bearing is installed at a position outside the belt of the rigid plate of the polishing head. The belt conveyance type polishing apparatus according to claim 1, wherein   2. The belt conveyance type polishing apparatus according to claim 1, wherein a work accommodating recess having a depth equal to the height of the work is provided on the conveyance belt as the clearance adjusting means.   The belt conveying polishing apparatus according to claim 1, wherein a work accommodating recess having a depth equal to the height of the work is installed in the polishing pad as the clearance adjusting mechanism.

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