JP2008200787A - Surface polishing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface polishing machine which polishes a surface, without irregularity or dirt due to transfer of polishing residue or polishing particles when polishing a color filter for a liquid crystal display device having projections, and achieves sufficiently favorable distribution in polishing quantity along the whole surface. <P>SOLUTION: (A) An upper polishing plate 65 that rotates and revolves is shaped like a wheel with spokes, composed of a boss, a rim, and an arm, having a groove 69 in a lower surface of the rim 67, communicating the inside and the outside of the wheel. (B) Above a lower polishing plate 62 that is fixed, a first polishing fluid dropping hose, and a first cleaning water dropping hose are provided, and above the rim inside the wheel, provided are: a second polishing fluid dropping hose 73 to drop polishing fluid onto a glass substrate positioned inside the wheel; and a second cleaning water dropping hose 74 to drop cleaning water. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flat surface polishing machine used for manufacturing a color filter for a liquid crystal display device. In particular, the present invention does not cause unevenness or dirt due to polishing wrinkles or abrasive particles, and polishes the variation in the polishing amount sufficiently satisfactorily. The present invention relates to a surface polishing machine that can be used.

In a display device, it is a useful means to use a color filter for purposes such as color display, reflectance reduction, contrast improvement, and spectral characteristic control.
In many cases, the color filter used in the display device is formed as a pixel. A photolithography method is widely used as a method of forming pixels of a color filter used in this display device.

FIG. 1 is a plan view schematically showing an example of a color filter used in a liquid crystal display device. 2 is a cross-sectional view of the color filter shown in FIG. 1 taken along line XX ′.
As shown in FIGS. 1 and 2, in the color filter used in the liquid crystal display device, a black matrix (51), a colored pixel (52), and a transparent conductive film (54) are sequentially formed on a glass substrate (50). It has been done.
FIG. 1 and FIG. 2 schematically show a color filter, and 12 colored pixels (52) are represented. In an actual color filter, for example, several hundreds are displayed on a 17-inch diagonal screen. A large number of colored pixels of about μm are arranged.

The black matrix (51) is a matrix having light shielding properties, and the colored pixels (52) have, for example, red, green, and blue filter functions.
The black matrix determines the position of the colored pixels of the color filter, makes the size uniform, and shields unwanted light when used in a display device, making the image of the display device uniform and uniform. In addition, it has a function of making an image with improved contrast.
This black matrix (51) is an example of being formed on a glass substrate (50) by a photolithography method using a black photoresist for forming a black matrix, and the black matrix formed using a resin is a resin black matrix. (51).

  The colored pixel (52) is a photolithography method using a negative colored photoresist in which a pigment such as a pigment is dispersed on the glass substrate (50) on which the resin black matrix (51) is formed. That is, it is formed as a colored pixel by exposure through a photomask to the coating film of the colored photoresist and development processing. Red, green, and blue colored pixels are sequentially formed.

  In order to suppress internal reflection in a liquid crystal display device that occurs when a metal such as chrome is used as a black matrix when using a high-brightness backlight such as a television, for example, In order to suppress electric field disturbance in a liquid crystal display device when a low-reflection resin black matrix is desired or used in, for example, an IPS (In Plane Switching) method, a highly insulating resin black matrix is used. It has been adopted when there is a need. However, the black matrix is gradually shifting from a black matrix using a metal such as chromium to a resin black matrix.

As the size of the glass substrate increases, the resin black matrix formed by photolithography using a black photoresist rather than the black matrix using a metal such as chromium as the black matrix material and forming a thin film with a vacuum device. The price is more advantageous, and the transition to resin black matrix is gradually progressing. Moreover, it tends to avoid using metals such as chromium in consideration of the environment.

The resin black matrix cannot obtain a high concentration in a thin film with a film thickness of about 100 nm to 200 nm, like a black matrix using a metal such as chromium, for example, a thickness of about 1.0 μm to 1.5 μm. To obtain the necessary high concentration.
When the film thickness of the resin black matrix becomes as thick as about 1.0 μm, for example, as shown in FIG. 2, the colored pixel (52) formed by overlapping the peripheral portion on the resin black matrix (51) The peripheral edge becomes a protrusion (53) on the end of the resin black matrix (51).

This protrusion (53) makes the surface of the color filter uneven, and deteriorates flatness. When a color filter having such a protrusion (53) and having a deteriorated surface flatness is used in a liquid crystal display device, the alignment of liquid crystal molecules is disturbed by the influence of the protrusion, and display quality such as display unevenness is deteriorated. Therefore, in many cases, the protrusions are removed by polishing the surface of the color filter.
When the protrusions are removed by polishing the surface of the color filter, at the same time, for example, the residue of the photoresist remaining on the colored pixels and on the peripheral edge of the glass substrate can be removed. This is preferable for the adhesion of the transparent conductive film in the film formation, or for the adhesion of the sealing agent when the peripheral portion is used as the seal portion with the counter substrate.

3 and 4 are explanatory views showing an outline of an example of an Oscar type polishing machine which is a flat polishing machine generally used when polishing the surface of a color filter for a liquid crystal display device. FIG. 3 is a plan view of the Oscar type polishing machine, and FIG. 4 is a cross-sectional view.
As shown in FIGS. 3 and 4, the rotating part of the polishing machine includes a disk-shaped lower surface plate (12), a rotary shaft (11) fixed integrally with the lower surface plate and rotating the lower surface plate, a disk-shaped surface plate. The upper surface plate (15), a rotary shaft (14) fixed integrally with the upper surface plate and rotating the upper surface plate, and a drive for turning (revolving) the upper surface plate (15) as shown by a dotted line in FIG. It is composed of a mechanism (not shown).

The size of the upper surface plate (15) is smaller than that of the lower surface plate (12), and a set polishing pressure (D) can be applied from the upper portion of the upper surface plate (15).
A polishing cloth (13) is bonded to the upper surface of the lower surface plate (12), and an abrasive droplet lower hose (16) is provided above the lower surface plate (12).

In the polishing method, first, the color filter (10) is attached to the lower surface of the upper surface plate (15) so that the surface of the color filter faces downward. For this attachment, for example, the back surface of the color filter (10) and the lower surface of the upper surface plate (15) are wetted with water, and the surface tension of water is applied to the lower surface of the upper surface plate (15).
Next, the polishing liquid (slurry) is dropped from the polishing droplet lower hose (16) above the polishing cloth (13), the upper surface plate (15) is lowered, and the set polishing pressure (D) is applied.
A rotating shaft (11) is driven by a motor (not shown) to rotate the lower surface plate (12) in a fixed direction (A), and the rotating shaft (14) is driven to move the upper surface plate (15). Is rotated (rotated) in a fixed direction (B), and the upper surface plate (15) is turned (revolved) in a fixed direction (C) by a drive mechanism (not shown) connected to the rotating shaft (14). . In this way, the surface of the color filter (10) is polished.

As the polishing cloth (13), for example, a foamed resin material having a JIS hardness of about 85, a non-woven fiber material, or the like is used. Further, as the polishing liquid (slurry), a dispersion in which an abrasive such as alumina, zirconia, cerium, manganese dioxide, silicon carbide, silica or the like having a primary particle size of 0.1 to 1.0 μm is dispersed. The content of the abrasive is about 1 wt%.

  However, in the polishing method for removing the protrusions on the surface of the color filter by the polishing process as described above, the polishing liquid dropped on the polishing cloth (13) is given from the outer peripheral portion of the upper surface plate (15). It is not sufficiently supplied to the central portion of the upper surface plate (15), and the central portion of the color filter surface tends to have a smaller polishing amount than other portions. That is, the entire surface of the color filter is not necessarily uniform, and there are differences in the degree of protrusion removal and the thickness of the colored pixels, resulting in display unevenness and chromaticity variations.

For example, Japanese Utility Model Laid-Open No. 6-9859 discloses a technique for efficiently supplying a polishing liquid between a polishing cloth and a glass substrate when an Oscar type polishing machine is used to polish a glass substrate such as a color filter. ing.
As shown in FIG. 5, in this technique, a work holding member (26) is provided on the lower surface of the upper surface plate (25), and the work holding member (26) holds the four corners of the work (glass substrate) (10). A holding portion (26a) is provided, and a gap (26b) is provided between the portion other than the holding portion (26a) and the polishing cloth so that the polishing liquid is efficiently supplied from the outside.

In the above publication, a hollow part (27) for supplying a polishing liquid from the outside is formed in the lower surface plate (22), and a large number of polishing liquids are supplied to the polishing cloth (23) in communication with the hollow part. The structure of the lower surface plate (22) provided with the supply port (28) is disclosed.
In this technique, the polishing liquid is efficiently supplied from the supply port (28) between the polishing cloth and the glass substrate.

Further, for example, Japanese Patent Application Laid-Open No. 2004-34216 discloses a polishing machine in which polishing liquid is reliably supplied and polishing unevenness does not occur when a glass substrate used in a display device is polished in an Oscar type polishing machine. Has been.
As shown in FIG. 6, in this polishing machine, slit grooves (37) are formed on the surface of the polishing cloth (33) on the lower surface plate (32). The slit grooves (37) are formed on the polishing cloth (33). ) With respect to the straight line (38) passing through the rotation center of (). Due to the rotation of the lower surface plate (32), a force to move to the center of rotation along the slit groove (37) acts on the polishing liquid, the polishing liquid is drawn in the direction of the rotation center, and the polishing liquid is at the center. This makes it easy to stay and makes it difficult to cause uneven polishing.

  Further, in the above polishing machine, the polishing cloth (33) is provided with a discharge hole (not shown) for allowing the polishing liquid to pass from the lower surface side to the upper surface side, and polishing provided on the lower surface plate (32). The polishing liquid is supplied from the discharge hole to the polishing cloth (33) through a liquid supply groove (not shown).

However, when any of the above techniques is applied to a color filter for a liquid crystal display device, for example, the color filter polishing tub or abrasive particles stay in the supply port, slit groove, discharge hole, etc., and these remain on the color filter surface. It may be transferred and cause unevenness and dirt on the surface of the color filter.
Further, the variation in the polishing amount on the surface of the color filter, that is, the removal of the protrusions and the variation in the thickness of the colored pixels are not sufficient.

On the other hand, the above-described Oscar type polishing machine is provided with a polishing cloth on the upper surface of the lower surface plate, a glass substrate is bonded to the lower surface of the upper surface plate smaller than the lower surface plate, and the glass substrate is pressed against the polishing cloth surface from above. On the other hand, a polishing machine called a reverse Oscar type polishing machine has been proposed in which the arrangement of the polishing cloth and the glass substrate is reversed upside down and the polishing liquid is spread over the entire surface of the glass substrate.

FIG. 7 is a plan view showing an outline of an example of an inverted Oscar-type polishing machine. As shown in FIG. 7, this polishing machine includes a fixed lower surface plate (42), a disk-shaped upper surface plate (45), and a rotating shaft (44) that is fixed integrally with the upper surface plate and rotates the upper surface plate. ), And a driving mechanism (not shown) for turning (revolving) the upper surface plate (45) as shown by a dotted line in FIG.
The size of the disk-shaped upper surface plate (45) is smaller than that of the lower surface plate (42), and a set polishing pressure can be applied from the upper portion of the upper surface plate (45).
A polishing cloth (43) is bonded to the lower surface of the upper surface plate (45), and a polishing liquid lower hose (46) is provided above the lower surface plate (42).

In the polishing method, first, the color filter (10) is attached to the upper surface of the lower surface plate (42) so that the surface of the color filter faces upward. Next, the polishing liquid (slurry) is dropped from the polishing liquid lower hose (46) above the color filter (10), the lower surface plate (45) is lowered, and the set polishing pressure is applied.
The upper surface plate (45) is driven to rotate the upper surface plate (45) in a fixed direction (B), and the upper surface plate is driven by a drive mechanism (not shown) connected to the rotation shaft (44). (45) is turned (revolved) in a certain direction (C). In this way, the surface of the color filter (10) is polished. The revolution radius (r1) of the upper surface plate (45) at this time is substantially the same as the radius (r2) of the upper surface plate (45).

However, even in this reverse Oscar type polishing machine, when applied to a color filter for a liquid crystal display device, the improvement of the tendency that the polishing amount of the central portion of the color filter (10) is insufficient is not sufficient.
Japanese Utility Model Publication No. 6-9859 JP 2004-34216 A

  The present invention has been made to solve the above-mentioned problem, a fixed lower surface plate on which a glass substrate is placed on the upper surface thereof, disposed above the lower surface plate, and provided with a polishing cloth on the lower surface thereof. A reverse Oscar type polishing machine, which is composed of a disk-shaped upper surface plate smaller than the lower surface plate, and polishes the glass substrate on the lower surface plate by rotation (rotation) and revolution of the upper surface plate, and has a protrusion. When the surface of a color filter for a liquid crystal display device is polished, the polishing flaws and particles of the color filter generated by the polishing are transferred to the surface of the color filter. It is an object of the present invention to provide a planar polishing machine capable of sufficiently satisfactorily polishing the variation in the polishing amount on the entire surface of the filter, that is, the removal of protrusions and the variation in the thickness of the colored pixels. Than is.

The present invention comprises a fixed lower surface plate on which a glass substrate is placed on the upper surface, an upper surface plate that is disposed above the lower surface plate, affixes a polishing cloth on the lower surface, and is smaller than the lower surface plate, In a planar polishing machine that polishes the glass substrate by simultaneously rotating (revolving) and revolving the upper platen while pressing the polishing cloth against the glass substrate on the lower platen and simultaneously supplying a polishing liquid onto the glass substrate.
A) The upper surface plate is composed of 1) a boss connected to the rotating shaft, a rim (annular ring) for attaching an abrasive cloth to the lower surface, and an arm (spoke) connecting the boss and the rim, and its plane The shape is a spoke wheel,
2) On the lower surface of the rim, there are a plurality of grooves communicating the inner side and the outer side of the ring of the rim,
B) Above the lower surface plate, there are provided a first polishing liquid drop hose for dripping the polishing liquid onto the glass substrate and a first washing water dropping hose for dripping the washing water, and the rim ring of the upper surface plate Above the inner side, a second polishing liquid drop hose for dropping a polishing liquid onto a glass substrate located inside the ring and a second washing water dropping hose for dropping washing water are provided. It is a surface polishing machine.

  The present invention comprises a fixed lower surface plate and an upper surface plate smaller than the lower surface plate disposed above, and rotates (revolves) and revolves the upper surface plate to press the polishing cloth against the glass substrate on the lower surface plate. In a flat polishing machine that supplies a polishing liquid onto a glass substrate and polishes, A) an upper surface plate 1) a boss that is connected to a rotating shaft, a rim that affixes a polishing cloth to the lower surface, and a connection between the boss and the rim 2) having a plurality of grooves communicating with the inner side and the outer side of the rim on the lower surface of the rim, and B) above the lower surface plate, a first polishing droplet lower hose, and A first washing water dropping hose for dripping the washing water is provided, and a second polishing water dropping hose for dripping the washing water and a second polishing water dropping hose are provided above the inner side of the ring of the rim of the upper surface plate. Because of the color filter polishing wrinkles and polishing caused by polishing Child is transferred to the color filter surface, without causing unevenness, stain in the color filter surface and, variations in polishing amount at the entire surface of the color filter surface becomes flat polisher that can sufficiently good polishing.

Embodiments of the present invention will be described below.
As a result of examining the variation of the polishing amount on the entire surface of the color filter when the color filter is polished using the inverse Oscar type polishing machine illustrated in FIG. Therefore, the present inventors have found that the amount of polishing on the surface of the color filter corresponding to the vicinity of the trajectory of the revolution of the upper surface plate is smaller than the amount of polishing on the other portions.

  The inventor first applied a sufficient polishing liquid to the entire surface of the color filter (10) on the lower surface plate (42) in advance using the reverse Oscar type polishing machine shown in FIG. The upper surface plate (45) is rotated (spinned) in a fixed direction (B), and the upper surface plate (45) is revolved in a fixed direction (C) while simultaneously pressing the polishing cloth against the color filter on the lower surface plate. As a result of polishing, a sufficiently good variation in polishing amount over the entire surface of the color filter surface was obtained.

Next, using the same reverse Oscar type polishing machine, polishing was performed by a conventional polishing method in which polishing was performed while dropping the polishing liquid from above the color filter (10).
FIG. 8 is an explanatory view showing measurement points at which the film thickness of the colored pixels of the color filter after polishing is measured. Reference symbols a to m represent measurement points, and dotted lines represent color filter portions corresponding to the revolution trajectory of the upper surface plate.
FIG. 9 is a graph showing the amount of polishing at each measurement point. The vertical axis of FIG. 9 is expressed by the amount of change in chromaticity (ΔRx) that correlates with the amount of change in the thickness of the colored pixel. It is.

  As shown in FIGS. 8 and 9, in the conventional polishing method using an inverse Oscar type polishing machine, the color filter portions (d, e, f, It is shown that the polishing amount of h, i, j) is smaller than the polishing amount of other portions. In the conventional polishing method, since the polishing amount variation was sufficiently good when a sufficient polishing liquid was applied to the entire surface of the color filter in advance, the polishing liquid was a polishing cloth. It is presumed that the variation in the amount of polishing becomes large because it does not reach the center of the substrate sufficiently.

FIG. 10 is a plan view showing an example of the upper surface plate in the present invention. 11 is a cross-sectional view taken along the line P-P in FIG. 10, FIG. 12 is a cross-sectional view taken along the line Q-Q in FIG. 10, and FIG. 13 is a side view taken from the direction R in FIG.
As shown in FIGS. 10 to 13, the upper surface plate (65) according to the present invention includes a boss (66) connected to the rotating shaft, a rim (annular ring) (67) for attaching an abrasive cloth to the lower surface, and the boss. And an arm (spoke) (68) for connecting the rim. The planar shape is a so-called upper surface plate that exhibits the shape of a so-called spoke wheel.

  A rotating shaft (64) is connected to the boss (66), and a polishing cloth is bonded to the lower surface of the rim (annular ring) (67). Further, a distance (E) is provided between the lower surface of the rim (67) and the lower surfaces of the boss (66) and the arm (68) so that the boss (66) and the arm (68) do not contact the lower color filter. Is provided.

  The rim (67) has a plurality of locations (67a) where grooves (69) are provided on the lower surface thereof. The groove (69) communicates the inner and outer rings of the rim. This groove (69) allows the color filter polishing soot and abrasive particles inside the ring of the rim generated by polishing to flow out of the ring from the ring inner side to the ring outer side, and the washing water dropped on the ring inner side from the ring inner side to the ring outer side. It is provided for discharging to

  FIG. 14 is a plan view showing an example of a surface polishing machine according to the present invention. As shown in FIG. 14, the surface polishing machine according to the present invention is fixed integrally with a fixed lower surface plate (62), a spoke wheel-shaped upper surface plate (65), and an upper surface plate, and rotates the upper surface plate. The rotary shaft (64) and the upper surface plate (65) are configured by a drive mechanism (not shown) that turns (revolves) as shown by a dotted line in FIG. The size of the upper surface plate (65) is smaller than that of the lower surface plate (62), and a set polishing pressure can be applied from the upper portion of the upper surface plate (65).

  Above the lower surface plate (62), a first polishing liquid lower hose (71) for dropping a polishing liquid onto the glass substrate (10) and a first washing water dropping hose (72) for dropping washing water are provided. ing. Further, above the inner side of the rim (67) of the rim (67) of the upper surface plate (65), a second polishing liquid lower hose (73) for dropping the polishing liquid onto the glass substrate located inside the ring and cleaning water are provided. A second washing water dropping hose (74) for dropping is provided. In the upper surface plate (65) illustrated in FIG. 10, the second polishing droplet lower hose (73) and the second washing water dropping hose (74) are attached to the arm (68). 65) Rotation and revolution following the rotation and revolution. However, the movement of the second polishing liquid lower hose (73) and the second cleaning water dropping hose (74) is not limited as long as the polishing liquid and the cleaning water are dropped inside the ring of the rim (67). For example, the movement may be only revolving without rotating.

  When polishing the color filter, the polishing cloth (63) is pressed against the color filter (10) on the lower surface plate (62) while rotating (revolving) and revolving the upper surface plate (65). The polishing liquid is dropped from the first polishing droplet lower hose (71) onto the color filter (10) located inside the ring of the rim (67) from the second polishing droplet lower hose (73). Drip and polish.

  Since the polishing liquid is dripped onto the central portion of the upper surface plate (65) inside the ring of the rim (67), the polishing liquid is sufficiently distributed to the central portion, and the upper surface plate (45 shown in FIG. 8 and FIG. 9). The polishing amount of the color filter portion (d, e, f, h, i, j) corresponding to the vicinity of the trajectory of revolution) is not smaller than the polishing amount of the other portions. The variation in polishing amount over the entire surface is sufficiently good.

Further, since a groove (69) is provided on the lower surface of the rim (67) so as to communicate the inner side and the outer side of the ring of the rim, the polishing pad and polishing particles of the color filter inside the ring of the rim generated by polishing Can easily flow out to the outside of the ring, and the washing water dropped inside the ring of the rim is easily discharged to the outside of the ring.
Therefore, the remaining polishing wrinkles and abrasive particles are not transferred to the color filter surface, and unevenness and dirt are not generated on the color filter surface.

It is the top view which showed typically an example of the color filter used for a liquid crystal display device. It is sectional drawing in the X-X 'line | wire of the color filter shown in FIG. It is the top view which showed the outline of an example of the Oscar type polisher. It is sectional drawing which showed the outline of an example of the Oscar type polisher. FIG. 6 is an illustration of the disclosed technique for supplying a polishing liquid. It is explanatory drawing of the disclosed grinding | polishing machine in which grinding | polishing nonuniformity does not arise. It is a top view which shows the outline of an example of a reverse Oscar type | mold grinder. It is explanatory drawing which shows the measuring point which measured the film thickness of the color pixel of the color filter after grinding | polishing. It is a graph showing the grinding | polishing amount in each measurement point. It is a top view which shows an example in the upper surface plate in this invention. It is sectional drawing in the PP line of FIG. It is sectional drawing in the QQ line of FIG. In FIG. 10, it is a side view from the code | symbol R direction. It is a top view which shows an example of the plane grinder by this invention.

Explanation of symbols

10 Color filter (glass substrate)
12, 22, 32 ... disk-shaped lower surface plates 11, 14, 44, 64 ... rotating shafts 15, 25, 35, 45 ... disk-shaped upper surface plates 13, 23, 33, 43 ... Polishing cloth 16, 46 ... Polishing droplet lower hose 26 ... Work holding member 27 ... Hollow portion 28 ... Supply port 37 ... Slit groove 38 ... Straight line 42 passing through the center of rotation ... Fixed lower surface plate 50 ... Glass substrate 51 ... Black matrix 52 ... Colored pixel 53 ... Protrusion 54 ... Transparent conductive film 62 ... Fixed lower surface plate 65 ... Book Upper surface plate 66 ... Upper surface plate boss 67 ... Upper surface plate rim (annular ring)
68 ... Upper surface plate arm (spoke)
69 ... groove 71 on the lower surface of the rim 71 ... first polishing droplet dropping hose 72 ... first washing droplet dropping hose 73 ... second polishing droplet dropping hose 74 ... second washing droplet dropping hose A ... Rotational direction B of lower surface plate ... Rotation (autorotation) direction of upper surface plate C ... Revolution directions am of upper surface plate ... Measurement points for measuring film thickness

Claims (1)

The upper surface plate is provided with a fixed lower surface plate for placing a glass substrate on the upper surface thereof, an upper surface plate that is disposed above the lower surface plate, a polishing cloth is pasted on the lower surface, and is smaller than the lower surface plate. In a plane polishing machine that presses the polishing cloth against the glass substrate on the lower surface plate while rotating (rotating) and revolving, and simultaneously supplying the polishing liquid onto the glass substrate to polish the glass substrate,
A) The upper surface plate is composed of 1) a boss connected to the rotating shaft, a rim (annular ring) for attaching an abrasive cloth to the lower surface, and an arm (spoke) connecting the boss and the rim, and its plane The shape is a spoke wheel,
2) On the lower surface of the rim, there are a plurality of grooves communicating the inner side and the outer side of the ring of the rim,
B) Above the lower surface plate, there are provided a first polishing liquid drop hose for dripping the polishing liquid onto the glass substrate and a first washing water dropping hose for dripping the washing water, and the rim ring of the upper surface plate Above the inner side, a second polishing liquid drop hose for dropping a polishing liquid onto a glass substrate located inside the ring and a second washing water dropping hose for dropping washing water are provided. Surface polishing machine.

Images