JP2008093739A - Substrate polishing device and substrate polishing method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate polishing device capable of polishing the under surface of the substrate with efficient productivity while ensuring uniformity in a polishing pressure surface. <P>SOLUTION: When the under surface of an array substrate 12 is polished by sucking the array substrate 12 got wet with water to a diaphragm membrane provided on the lower surface of a rotary head 102 to mount on a turn table, and rotating the rotary head 102 and the turn table in the same direction, and in an eccentric state, the suction state of the diaphragm membrane got wet with water is immediately separated by using a Teflon plate 118 having water-repellent property on the lower surface of the rotary head 102. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a substrate polishing apparatus for polishing a substrate such as an array substrate of a liquid crystal display device and a substrate polishing method using the same.

  In the current liquid crystal display device, a liquid crystal layer is sandwiched between two glass substrates having electrodes, and the periphery of the two glass substrates is fixed with an adhesive except for the liquid crystal sealing port. The structure sealed with the sealing material is comprised. A spacer for keeping the distance between the two glass substrates constant is installed on the substrate.

Among them, in a liquid crystal display device for color display, a color filter having an RGB colored layer is formed on one of two glass substrates. For example, in a liquid crystal display device using a color type active matrix driving method, a semiconductor layer made of a thin film transistor (hereinafter simply referred to as TFT) made of a semiconductor such as polysilicon or amorphous silicon, and a pixel electrode connected to the semiconductor layer And an array substrate on which a source electrode and a gate electrode are formed, and a counter electrode disposed opposite to the array substrate, and an RGB colored layer is formed on the array substrate (for example, see Patent Document 1). .
JP 2000-171784 A

  In the liquid crystal display device having a colored layer on the array substrate as described above, the portion provided with the RGB colored layer is raised by the influence of shrinkage during curing as compared with the other portions. Due to the rise, when black is displayed, light is lost from this portion and the contrast is lowered. Therefore, in order to prevent this decrease in contrast, the raised portion is removed by polishing with an abrasive.

  However, recent glass substrates for liquid crystal display devices have been increased in size to improve production efficiency, and it is necessary to ensure uniformity in the polishing pressure surface when polishing such large substrates. On the other hand, it is necessary not only to ensure the uniformity in the polishing pressure surface but also to improve the working efficiency.

  Accordingly, in view of the above problems, the present invention provides a substrate polishing apparatus and a substrate polishing method using the same that can polish the lower surface of the substrate with efficient productivity while ensuring uniformity in the polishing pressure surface.

  The present invention sucks and conveys the substrate to the lower surface of the rotating head, places the substrate on a polishing pad on the upper surface of a turntable, presses the substrate against the polishing pad by the rotating head, and rotates the rotation. In a substrate polishing apparatus that polishes the lower surface of the substrate while rotating a head and the turntable and spraying slurry containing an abrasive, the lower surface of the rotating head is covered with an elastic diaphragm film, and An adsorption space is provided between the diaphragm film and the rotary head, the diaphragm film has a plurality of air holes, a water repellent portion is provided on the lower surface of the rotary head, and the lower surface of the rotary head has the In order to suck the substrate, suction means for sucking air in the suction space is provided, and the substrate is pressed against the turntable by the rotary head. To a substrate polishing apparatus, wherein a pressurizing means for supplying air is provided in the suction space.

  In the substrate polishing apparatus of the present invention, when a substrate wetted with water is sucked and transported to the lower surface of the rotating head, the diaphragm film wet with water is attracted to the lower surface of the rotating head due to the suction force to suck the substrate. It will be. However, when the substrate is pressed against the polishing pad of the turntable by the rotating head, the adsorbed diaphragm film is immediately separated from the lower surface of the rotating head because the water repellent portion is provided on the lower surface of the rotating head. The pressure increases, and the substrate can be pressed against the polishing pad. Therefore, production efficiency can be improved.

(First embodiment)
Hereinafter, a liquid crystal display device 10 according to a first embodiment of the present invention will be described with reference to FIGS.

(1) Structure of Liquid Crystal Display Device 10 The liquid crystal display device of this embodiment includes an array substrate 12 having 640 vertical pixels and 480 × 3 (R, G, B) horizontal pixels.

  In the array substrate 12, 640 gate lines 16 are wired in the horizontal direction of the glass substrate 14, and 480 × 3 signal lines 18 are wired in a matrix so as to be orthogonal to the gate lines 16. In addition, 640 auxiliary capacitance lines 20 are also wired in parallel with the gate lines 16.

  A TFT 22 which is a switching element made of a polysilicon semiconductor is formed in the vicinity of the intersection of the gate line 16 and the signal line 18. A gate line 16 is connected to the gate electrode of the TFT 22, a signal line 18 is connected to the source electrode of the TFT 22, and a pixel electrode 24 is connected to the drain electrode of the TFT 22.

  Colored layers 26R, 26G, and 26B that form color filters (R, G, and B) of different colors are formed for each pixel.

  As shown in FIG. 10, a counter substrate 13 is disposed to face the array substrate 12. A liquid crystal layer 15 is sandwiched between the counter substrate 13 and the array substrate 12, and a spacer 28 is formed in a protruding shape on the colored layer 26 to maintain the cell gap (FIG. 6, FIG. (See FIG. 10).

  Hereinafter, a method for manufacturing the liquid crystal display device 10 will be described in order.

(2) Manufacturing Method of Liquid Crystal Display Device 10 In the following steps, the liquid crystal display device 10 is manufactured after processing the four array substrates 12 on a large glass substrate.

(2-1) First Step In the first step, 640 gate lines 16 and 640 auxiliary capacitance lines 20 are formed laterally on the glass substrate 14 constituting the large glass substrate. The auxiliary capacitance line 20 is formed with a width of 80 μm, and a hole 30 having a hexagonal planar shape is formed at the intersection with the signal line 18. A part is left so that the auxiliary capacitance line 20 is not disconnected by the hole 30. The size of the hole 30 is 20 μm. The process of forming the TFT 22 is performed simultaneously with this process and the following processes.

(2-2) Second Step In the second step, an interlayer insulating film 32 is formed on the layer on which the gate line 16 and the auxiliary capacitance line 20 are formed.

(2-3) Third Step In the third step, 480 × 3 signal lines 18 are formed. The width of the signal line 18 is 26 μm, and the overlapping portion with the auxiliary capacitance line 20 has a hexagonal planar shape in the upper layer of the hole 60 as shown in FIG. 2, and is thicker than other signal line 18 portions. ing.

(2-4) Fourth Step In the fourth step, the signal line 18 is formed, and an ultraviolet curable acrylic resin resist in which a blue (B) pigment is dispersed is applied to the entire surface by a spinner, and colored blue. Irradiate 100 mJ / cm ² at a wavelength of 365 nm through a photomask that irradiates light on a desired portion. Thereafter, development is carried out with a 1% aqueous solution of KOH for 10 seconds, and a blue colored layer 26G having a thickness of 3.0 μm is formed in that portion.

(2-5) Fifth Step In the fifth step, a green colored layer having a thickness of 3.0 μm is used in the same manner as in the fourth step, using an ultraviolet curable acrylic resin resist in which a green (G) pigment is dispersed. 26G is formed.

(2-6) Sixth Step In the sixth step, a red colored layer having a thickness of 3.0 μm is used in the same manner as in the fourth step, using an ultraviolet curable acrylic resin resist in which a red (R) pigment is dispersed. 26R is formed.

(2-7) Seventh Step In the seventh step, polishing is performed using the substrate polishing apparatus 100 described below, the raised portions of the colored layers 26G, B, and R are removed, and then washed with a sponge made of polyvinyl alcohol. After that, the array substrate 12 is dried by ultrasonic cleaning with pure water.

(2-8) Eighth Step In the eighth step, an ITO film having a thickness of 150 nm is formed as the transparent pixel electrode 24 by sputtering and patterned into a pixel electrode shape.

(2-9) Ninth Step In the ninth step, a photosensitive carbonless black resin is applied to a thickness of 3.0 μm using a spinner, dried at 90 ° C. for 10 minutes, and then 365 nm using a photomask. After being exposed at an exposure amount of 500 mJ / cm ² at a wavelength of 1, a development is performed with an alkaline aqueous solution having a pH of 11.5, and the frame portion 27 is formed by baking at 220 ° C. for 60 minutes.

(2-10) Tenth Step In the tenth step, a photosensitive transparent acrylic resin is applied to a thickness of 5.5 μm with a spinner, dried at 90 ° C. for 10 minutes, and at a wavelength of 365 nm using a photomask, 500 mJ A spacer 28 is formed on the base 27 at / cm ² . The spacer 28 has a protruding shape as shown in FIG. The spacer 28 has a diameter of 8 μm and stands above the hole 30.

(2-11) Eleventh Step In the eleventh step, AL-1051 (manufactured by JSR Corporation) is applied to the entire surface by 50 nm as an alignment film material, a rubbing treatment is performed, and an alignment film 29 is formed.

(2-12) Twelfth Step In the twelfth step, an ITO film having a thickness of 150 nm is formed on the counter substrate 13 as a transparent electrode by a sputtering method, and then the same as the alignment film material is applied and a rubbing process is performed. An alignment film is formed. The rubbing direction on the counter substrate 13 is also matched with the signal line direction.

(2-13) Thirteenth Step In the thirteenth step, the sealing agent 31 is printed along the periphery of the alignment film of the array substrate 12 other than the liquid crystal injection port, and a voltage is applied to the counter electrode of the counter substrate 13. An electrode dislocation material is formed on the electrode dislocation electrode around the adhesive.

(2-14) Fourteenth Step In the fourteenth step, the counter substrate 13 is arranged so that the alignment films 29 face each other and the respective rubbing directions are 90 °, and the sealing agent 31 is cured by heating to form an array. The substrate 12 and the counter substrate 13 are bonded together. At this time, the cell gap between the array substrate 12 and the counter substrate 13 is determined by the spacer 28.

(2-15) Fifteenth Step In the fifteenth step, a liquid crystal composition is injected from a liquid crystal injection port, and then the liquid crystal injection port is sealed with an ultraviolet curable resin.

(2-16) Sixteenth Step In the sixteenth step, the large glass substrate is divided to form four liquid crystal cells.

(3) Structure of Substrate Polishing Apparatus 100 Hereinafter, the structure of the substrate polishing apparatus 100 that polishes the colored layer 24 in the seventh step will be described with reference to FIGS.

  The substrate polishing apparatus 100 has a movable rotary head 102 and a turntable 104.

  The turntable 104 has a circular planar shape and rotates with the rotation shaft 106 stopped. Note that the position of the turntable 104 is fixed. Inside the rotating shaft 106, there is provided a spraying port 108 for spraying a slurry mainly containing water containing a silica gel abrasive to the center of the turntable 104. A sheet-like polishing pad 110 is provided on the upper surface of the turntable 104.

  The planar shape of the rotary head 102 is circular, can be rotated about a rotary shaft 112, and can move so that the substrate 12 can be conveyed to the position of the turntable 104.

  An aluminum rubber plate 114 is provided on the lower surface of the rotary head 102. The rubber plate 114 is circular, and a rectangular partition 116 that is slightly larger than the size of the array substrate 12 protrudes downward on the inner peripheral side thereof.

  A water-repellent Teflon plate 118 is provided inside the partition wall 116 of the rubber plate 114. Teflon is a registered trademark. In this application, all are the same.

  A diaphragm film 120 made of rubber having a circular planar shape is attached to the lower surface of the rotary head 102 so as to cover the rubber plate 114. A plurality of air holes 122 pass through the diaphragm film 120. The positions where the air holes 122 are provided are inside the partition wall 116 of the rubber plate 114. In addition, an O-ring 124 is provided on the inner peripheral side of the diaphragm film 120 and the partition wall 116 to prevent air escape. The closed space formed by the Teflon plate 118, the partition wall 116, and the diaphragm film 120 is hereinafter referred to as an adsorption space 126. Further, a pump 128 is provided through which the pipe 130 also penetrates the rotary head 102 and the Teflon plate 118 to adsorb the air in the adsorption space 126 and send the air to the adsorption space 126.

(4) Substrate Polishing Method Next, a method for polishing the array substrate 12 using the substrate polishing apparatus 100 having the above configuration will be described in order.

  First, the array substrate 12 on which the colored layer 24 is formed is inverted, and is stored in a water storage section in which water is stored so that the colored layer 24 is on the lower surface side. In this state, the rotary head 102 is positioned at the position of the array substrate 12. Move to. Then, the diaphragm film 120 is pressed against the upper surface of the array substrate 12 wetted with water, and the air inside the adsorption space 126 is adsorbed by the pump 128 to be in a substantially vacuum state, whereby the lower surface of the rotary head 102 is wetted with water. The substrate 12 is vacuum-adsorbed.

  Next, the array substrate 12 wetted with water vacuum-adsorbed on the lower surface of the rotary head 102 is moved above the turntable 104, and the array substrate 12 is placed on the polishing pad 110. In this case, the rotating shaft 106 of the turntable 104 and the rotating shaft 112 of the rotating head 102 are placed at eccentric positions as shown in FIG.

  Next, vacuum suction by the pump 128 is stopped, and 10 kPa of air is supplied from the pipe 130. As a result, the pressure applied to the entire array substrate 12 wetted with water reaches approximately 10 kPa in 10 seconds. The reason for this is that since the array substrate 12 is wet with water, the diaphragm film 120 is also wet with water, so that the diaphragm film 120 wet with water is adsorbed to the Teflon plate 118 by vacuum suction. It has become. However, since the Teflon plate 118 is water repellent, the diaphragm film 120 can be immediately separated from the Teflon plate 118 to form the adsorption space 126. If the Teflon plate 118 is not provided and the rubber plate 114 is exposed, since the rubber plate 114 is made of aluminum, the diaphragm film 120 wet with water is attracted to the lower surface of the rubber plate 114 and is not easily separated. It takes 60 seconds for the pressure in the adsorption space 126 to reach 10 kPa. Therefore, the production time of 50 seconds can be shortened by providing the Teflon plate 118.

  Next, the pressure is maintained at 10 kPa, and a slurry containing water containing silica gel abrasive as a main component is sprayed from the slurry spraying tube 132 on the side of the rotary head 102 and sprayed from the spraying port 108 of the turntable 104. .

  Next, the rotary head 102 and the turntable 104 are rotated in the same rotational direction so that the rotational speed of the rotary head 102 is larger. For example, the turntable 104 is rotated at 30 times / minute, and the rotary head 102 is rotated at 31 times / minute. Polishing is performed by performing this state for 40 seconds.

  Next, after the polishing process is completed, the slurry supply is stopped, the pressurization of the array substrate 12 is reduced to 5 kPa, and the rotary head 102 and the turntable 104 are rotated in the same direction at 10 times / minute for 10 seconds. The array substrate 12 is cleaned by supplying pure water as water. Thereafter, the rotary head 102 and the turntable 104 are stopped.

  Next, the array substrate 12 is again adsorbed by the rotary head 102, is released into the atmosphere, and the array substrate 12 is taken out and sent to the next step.

  In the next step, the array substrate is rubbed with a sponge made of polyvinyl alcohol, ultrasonically washed with pure water, and the array substrate 12 is spin-dried.

  As described above, the colored layer 12 of the array substrate 12 can be polished with uniformity in the polishing pressure surface, and the production time can be shortened.

(5) Modified Example In the above embodiment, the Teflon plate 118 is provided as the water repellent material provided on the lower surface of the rubber plate 114, but other plate materials having water repellency may be used instead.

  Further, a water repellent having water repellency may be applied to the lower surface of the rubber plate 114.

FIG. 3 is a plan view of a state in which auxiliary capacitance lines, gate lines, and signal lines are wired in the array substrate showing one embodiment of the present invention. It is an enlarged view of A part in FIG. It is the BB sectional view taken on the line in FIG. It is a top view of an array substrate. FIG. 5 is an enlarged view of a portion B in FIG. 4. It is the DD sectional view taken on the line in FIG. 1 is a side view of a substrate polishing apparatus showing an embodiment of the present invention. It is a longitudinal cross-sectional view of a rotary head. It is a bottom view of a rotary head. It is the perspective view which notched some liquid crystal display devices of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Liquid crystal display device 12 Array substrate 13 Opposite substrate 14 Glass substrate 16 Gate line 18 Signal line 20 Auxiliary capacity line 22 TFT
24 pixel electrode 26 colored layer 28 spacer 30 hole portion 32 interlayer insulating film 34 wall portion 100 substrate polishing apparatus 102 rotating head 104 turntable 106 rotating shaft 108 spraying port 110 polishing pad 112 rotating shaft 114 rubber plate 116 partition wall 118 Teflon plate 120 diaphragm Membrane 122 Air hole 124 O-ring 126 Adsorption space 128 Pump 130 Pipe 132 Slurry spray pipe

Claims (12)

The substrate is sucked and transported to the lower surface of the rotating head, the substrate is placed on a polishing pad on the upper surface of a turntable, the substrate is pressed against the polishing pad by the rotating head, and the rotating head and the turn In the substrate polishing apparatus for rotating the table and polishing the lower surface of the substrate while spraying the slurry containing the abrasive,
The lower surface of the rotating head is covered with an elastic diaphragm film, and an adsorption space is provided between the diaphragm film and the rotating head;
The diaphragm membrane has a plurality of air holes,
A water repellent part is provided on the lower surface of the rotary head,
In order to adsorb the substrate to the lower surface of the rotary head, a suction means for sucking air in the adsorption space is provided,
In order to press the substrate against the turntable by the rotating head, pressurizing means for supplying air to the adsorption space is provided. The substrate polishing apparatus according to claim 1, wherein the water-repellent part is a water-repellent plate provided on a lower surface of the rotary head. The substrate polishing apparatus according to claim 2, wherein the plate material is a Teflon plate. The substrate polishing apparatus according to claim 1, wherein the water repellent portion is a water repellent layer applied to a lower surface of the rotary head. The substrate polishing apparatus according to claim 1, wherein a size of the adsorption space is 0.5 to 3.0 mm. The substrate polishing apparatus according to claim 1, wherein a template that surrounds and positions the substrate is provided on a lower surface of the diaphragm film. The substrate polishing apparatus according to claim 1, wherein the rotary head and the turntable are rotated in the same direction and at different rotational speeds. The substrate polishing apparatus according to claim 7, wherein the rotational speed of the rotary head is faster than the rotational speed of the turntable. The substrate polishing apparatus according to claim 1, wherein a rotation axis of the rotary head and a rotation axis of the turntable are eccentric. The substrate polishing apparatus according to claim 1, wherein the substrate is an array substrate of a liquid crystal display device. The substrate polishing apparatus according to claim 1, wherein an object to be polished on the lower surface of the substrate is a colored layer in an array substrate of a liquid crystal display device. A substrate polishing method for polishing a substrate using the substrate polishing apparatus according to claim 1,
A first step of adsorbing and transporting a substrate wet with water to the lower surface of the rotary head;
A second step of placing the substrate on a polishing pad on an upper surface of a turntable by the rotary head;
A third step of pressing the substrate against the polishing pad by the rotating head;
A fourth step of polishing the lower surface of the substrate while rotating the rotating head and the turntable and spraying a slurry containing an abrasive;
A substrate polishing method characterized by comprising:

Images