JP2008180796A - Method and apparatus for correcting defect - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique which can always stably perform levelling (film thickness equalization) of ink applied onto a defect part. <P>SOLUTION: A method of correcting defects has a step (S20) of applying a liquid material onto a minute region on a substrate and a step (S40) of pressurizing the applied liquid material by pressing a pressurizing head having a flat surface facing the substrate to the substrate so that the flat surface covers whole minute region. Levelling for uniformizing thickness of the liquid material can be performed by uniformly pressurizing the liquid material at the whole minute region and consequently defect correction of high quality can be attained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a defect correction method and a defect correction apparatus, and more particularly to a defect correction method and a defect correction apparatus for correcting a defect by applying a liquid material to a fine region on a substrate.

  In recent years, with the increase in size and resolution of LCDs (Liquid Crystal Displays, liquid crystal displays), the number of pixels has increased, making it difficult to manufacture LCDs without defects and increasing the probability of occurrence of defects. Under these circumstances, in order to improve the yield, a defect correction apparatus that converts non-defective products by correcting defects generated in the manufacturing process of the color filter of the LCD is indispensable for the production line.

  Recently, LCDs having a size of about 37 to 45 inches are commercially available, and the size of one pixel has increased from about 60 μm × 200 μm to about 200 μm × 600 μm of a small panel. As the pixel size increases, the defect size also increases and the correction size also increases. In such a situation, even a correction quality that was not a problem with a conventional small correction size may become a problem because it becomes an area that can be seen with a large correction size.

  FIGS. 5A to 5C are diagrams showing defects that occur in the manufacturing process of the color filter of the LCD. As shown in FIGS. 5A to 5C, the color filter includes a transparent substrate, a lattice pattern called a black matrix 300 formed on the surface thereof, and a plurality of sets of R (red) pixels 301, G. (Green) pixel 302 and B (blue) pixel 303. In the manufacturing process of the color filter, the white defect 304 in which the color of the pixel or the black matrix 300 is lost as shown in FIG. 5A, or the color of the adjacent pixel is mixed as shown in FIG. 5B. Or a black defect 305 in which the black matrix 300 protrudes from the pixel, or a foreign substance defect 306 in which a foreign substance adheres to the pixel as shown in FIG.

  As a method for correcting the white defect 304, the same color ink as the pixel in which the white defect 304 exists is attached to the tip of the application needle, and the ink attached to the tip of the needle is transferred to the white defect 304 to cover the white defect 304. There is a way. As a method for correcting the black defect 305 and the foreign substance defect 306, the defective portion is removed by laser light irradiation to form a laser cut portion, and the same color ink as the pixel in which the laser cut portion exists is applied to the laser cut portion. There is a method of forming an ink application part by coating. An apparatus for correcting defects by applying ink is proposed in Patent Document 1, for example.

  FIG. 6 is a schematic diagram illustrating a black defect correction method. As shown in FIG. 6A, for example, when the black defect 305 is generated in the G pixel 302 of the transparent substrate of the color filter, the black defect 305 and the surrounding G pixel 302 are irradiated by irradiating the black defect 305 with laser light. The rectangular laser cut part 310 shown in FIG.6 (b) is formed by removing. Thereafter, the black defect 305 is corrected by applying an ink of the same color as that of the G pixel 302 to the laser cut unit 310.

  Conventionally, correction is performed by applying an amount of ink larger than the volume of the laser cut portion 310 and applying the ink so that the ink protrudes from the laser cut portion 310. However, along with the higher precision of LCDs, the requirement for quality after defect correction becomes stricter, and there is a demand for correction that does not protrude ink from the laser cut unit 310. In order to correct the ink without protruding, the ink is applied in the vicinity of the center of the laser cut portion 310 as shown in FIG.

  In this case, when the viscosity of the ink is high and the fluidity is poor, the surface tension of the applied ink acts, so that, for example, the application needle with the ink attached to the tip is brought into contact with the application object and the ink is applied. Sometimes, ink may not be applied over all of the areas where it should originally be applied. For example, in FIG. 6C, the ink application part 311 does not reach the entire laser cut part 310, and a gap 312 where no ink is applied is generated near the corner of the rectangular laser cut part 310. That is, as shown in FIG. 6D, which shows a cross-section taken along the line VID-VID in FIG. 6C, the ink application unit 311 is formed over the entire laser cut unit 310 near the center of the laser cut unit 310. Is formed. On the other hand, as shown in FIG. 6E, which is a cross-sectional view taken along the line VIE-VIE in FIG. 6C, a gap 312 that is not coated with ink is generated in the vicinity of the corner of the laser cut portion 310. The substrate 2 is exposed in the gap 312.

When the ink is applied again to the laser cut unit 310 in order to eliminate the gap 312, the color of the corrected ink application unit 311 that is excessively applied and the ink protrudes from the laser cut unit 310. There is a problem in quality after the defect correction, such as that is darker than the G pixel 302. Therefore, in order to eliminate the gap 312, a method has been proposed in which air is blown to the ink application part 311 to make the ink film thickness uniform (leveling) (see, for example, Patent Document 2). In this case, since the ink protrudes from the laser cut unit 310 by air blowing, a step of removing the protruding ink by washing after the ink application unit 311 is cured by exposure is provided.
JP 9-236933 A Japanese Patent Laid-Open No. 1-96601

  In the leveling method for blowing air proposed in Patent Document 2, there are cases where leveling cannot be performed because the blowing direction of air is limited. FIG. 7 is a schematic diagram illustrating an example of an ink application unit before and after air ejection. FIG. 7A is a schematic plan view showing the ink application part 311 before air ejection and the air ejection nozzle. FIG.7 (b) is a schematic diagram which shows the cross section by the VIIB-VIIB line | wire of Fig.7 (a). FIG. 7C is a schematic plan view showing the ink application part 311 after air ejection. FIG.7 (d) is a schematic diagram which shows the cross section by the VIID-VIID line | wire of FIG.7 (c).

  As shown in FIG. 7B, the air injected from the air injection nozzle 121 flows along the arrow 122. That is, as shown in FIG. 7B, when air is ejected in a state where the air ejection nozzle 121 is inclined with respect to the surface of the substrate 2, the air flow 122 on the surface of the ink application unit 311 is changed to the air ejection. The flow is directed from one side close to the nozzle 121 (right side in FIG. 7B) toward the other side away from the air injection nozzle 121 (left side in FIG. 7B). As a result, after air injection, as shown in FIG. 7C, the one-side gap 312 cannot be eliminated. Further, as shown in FIG. 7D, the ink application part 311 has a bias 313 on the other side. As described above, in the leveling method in which air is blown to the ink application part 311, there is a problem that the ink cannot often be leveled over the entire laser cut part 310.

  Therefore, a main object of the present invention is to provide a technique that can always achieve stable leveling in a method for promoting leveling (thickness uniformity) of ink applied to a defective portion.

  In the defect correction method according to the present invention, a liquid material is applied to a fine region on a substrate to correct the defect. The defect correction method includes a step of applying a liquid material to a fine region. Further, the method includes a step of pressing the applied liquid material by pressing a pressure head having a flat surface facing the substrate against the substrate such that the flat surface covers the entire fine region.

  In this case, leveling can be performed to make the thickness of the liquid material uniform by uniformly applying pressure to the applied liquid material in all of the fine regions where the liquid material such as ink is to be spread and spread. There is no problem that the liquid material sticks out like the conventional method of re-applying the liquid material, or the color becomes too dark when the liquid material is ink. High-quality defect correction is possible without the problem of occurrence of bias.

  Preferably, in the pressurizing step, the flat surface is covered with a resin film. In this case, since pressure is applied with a resin film interposed, it is possible to prevent the liquid material from adhering to the pressure head. Therefore, it is not necessary to clean the pressure head, and the process can be simplified.

  Preferably, after the pressurizing step, the resin film is positioned relative to the pressurizing head so that a portion different from the portion covering the flat surface when the pressurizing step is performed on the resin film covers the flat surface. Further comprising the step of automatically moving. In this case, even when the liquid material adheres to the resin film, by moving the resin film relative to the pressure head, the portion of the resin film that covers the pressure head is replaced, so that the resin is always clean. It is possible to press the film surface in contact with the substrate.

  Preferably, the method further includes a step of curing the liquid material between the step of applying and the step of applying pressure. In this case, by drying the liquid material before pressurization and curing the liquid material to such an extent that it can be plastically deformed, the liquid material becomes more difficult to adhere to the pressure head or the resin film. Therefore, the man-hours required for cleaning the pressure head and replacing the resin film can be reduced.

  A defect correction apparatus according to the present invention is a defect correction apparatus used in any of the above defect correction methods. The defect correction apparatus includes an application mechanism that applies a liquid material to a fine region on a substrate. Further, a pressure head having a flat surface facing the substrate is provided. In addition, a drive unit that moves the pressure head in a direction intersecting the surface of the substrate is provided. The orthogonal projection onto the flat substrate can cover and hide the entire fine region. In this case, since the liquid material is uniformly pressurized in the entire fine region, leveling to make the thickness of the liquid material uniform is possible, so that high-quality defect correction is possible.

  According to the defect correcting method and the defect correcting apparatus of the present invention, the leveling of the ink applied to the defective part (uniform film thickness) can always be performed stably.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  FIG. 1 is a diagram showing the overall configuration of the defect correction apparatus. As shown in FIG. 1, this defect correction apparatus 1 includes a defect correction head unit that includes an observation optical system 6, a CCD camera 7, a laser 8, an ink application mechanism 9, an ink curing illumination 10, and a pressure mechanism 11. Prepare.

  In addition, a positioning mechanism is provided that performs positioning by relatively moving the defect correction head unit and the substrate table. The positioning mechanism includes a Z-axis table 5 as a first sub-driving unit that moves the defect correction head unit in a direction perpendicular to the substrate 2 (Z-axis direction). The positioning mechanism includes an X-axis table 3 as a second sub-driving unit that mounts the Z-axis table 5 and moves the Z-axis table 5 in the X-axis direction substantially parallel to the substrate 2. The positioning mechanism includes a Y-axis table 4 as a substrate table on which the substrate 2 is placed and moves the substrate 2 in the Y-axis direction orthogonal to the X-axis direction and substantially parallel to the substrate.

  The defect correction apparatus 1 also includes a control computer 12 that controls the operation of the entire apparatus, and an operation panel 13 for inputting commands from the operator to the control computer 12.

  The observation optical system 6 is for observing the surface state of the substrate 2 (including a defective portion on the surface of the substrate 2). An image observed by the observation optical system 6 is converted into an electrical signal by the CCD camera 7 and displayed on the monitor screen of the control computer 12. The laser 8 is used for irradiating the substrate 2 with laser light. When the substrate 2 is formed with an LCD color filter, black defects and foreign matter defects generated on the substrate 2 are removed by laser light irradiation.

  The ink application mechanism 9 applies and corrects the ink attached to the tip of the application needle on a fine region on the substrate 2. That is, the ink application mechanism 9 is an application mechanism that applies ink as a liquid material to a fine region on the substrate. When the substrate 2 is formed with an LCD color filter, the fine region is a concave laser-cut portion formed on the substrate 2 by removing white defects, black defects, or foreign matter defects. is there. The ink curing illumination 10 irradiates light for curing the ink applied by the ink application mechanism 9. When the ink is of an ultraviolet curing type, the ultraviolet illumination is selected as the ink curing illumination 10 and mounted on the apparatus. When the ink is a thermosetting type, the halogen lamp illumination is selected as the ink curing illumination 10 and is mounted on the apparatus.

  The pressure mechanism 11 includes a pressure head having a flat surface facing the substrate 2 and a drive unit that moves the pressure head in a direction intersecting the surface of the substrate 2. The pressure head is shaped such that the orthogonal projection of the flat surface onto the substrate 2 can cover and hide all of the fine regions. That is, for example, when the flat surface is a rectangle, the pressure head is molded so that the orthogonal projection that is a set of perpendicular legs drawn from the four sides of the rectangle to the substrate 2 covers the entire fine region on the surface of the substrate 2. Is done. Therefore, when the driving unit is driven to move the pressure head toward the substrate 2 and the pressure head is brought into contact with the substrate 2, the flat surface, which is the portion that contacts the substrate 2 in the pressure head, is smaller than the fine region. Therefore, the flat surface can cover the entire fine region. At this time, if the liquid material is applied to the fine region, the liquid material can be uniformly pressurized in the entire fine region.

  Note that the shape of the flat surface of the pressure head is not limited to a rectangle, and may be any shape such as a circular shape or other polygonal shapes. The flat surface may be any size as long as it can cover the entire fine region. For example, when the substrate is a color filter, the size of the flat surface may be determined according to the size of one pixel surrounded by the black matrix (for example, the same size as the size of one pixel). The dimension of the flat surface may be larger than the dimension of one pixel. For example, the outer peripheral shape of the flat surface may be similar to the shape of one pixel, and may be a size that can press the inside of the pixel at a time in that shape, or 95% of the size of the corresponding pixel. Good. Further, the pressure head may be a resin molded product, and the pressure head may be made of metal as long as the pressure head comes into contact with the substrate with a resin film interposed as will be described later.

  FIG. 2 is a block diagram showing components of the defect correction apparatus. As shown in FIG. 2, the operation of each component of the defect correcting apparatus 1, that is, the observation optical system 6, the laser 8, the ink application mechanism 9, the ink curing illumination 10, the pressurizing mechanism 11, and the positioning mechanism is controlled. It is controlled by the computer 12. The pressurizing mechanism 11 moves the resin film relative to the pressurizing head and the pressurizing head driving mechanism as a driving unit that moves the pressurizing head in a direction intersecting the substrate surface, for example, in the vertical direction. A resin film moving mechanism. With this apparatus configuration, it is possible to correct defects in fine areas on the substrate, for example, white defects, black defects, and foreign matter defects generated in the color filter.

  Next, a method for correcting a defect by applying a liquid material to a fine region on the substrate 2 using the defect correction apparatus 1 will be described. FIG. 3 is a flowchart showing the defect correction method. FIG. 4 is a schematic diagram showing an ink pressurizing step. FIG. 4A is a plan view showing a state in which ink is applied to the laser cut portion after the black defect generated in the G pixel 302 of the color filter is removed by laser light irradiation. FIG. 4B is a cross-sectional view of the substrate 2 in the cross section taken along line IVB-IVB shown in FIG. 4A, and also shows the pressure head 21 before contacting the ink application unit 311. . FIG. 4C is a cross-sectional view of the substrate 2 showing a state in which the pressure head 21 is in contact with the ink application unit 311 and pressurizing ink as a liquid material. FIG. 4D is a plan view showing a state after ink pressure is applied. FIG. 4E is a cross-sectional view of the substrate 2 taken along the line IVE-IVE shown in FIG.

  First, in the step (S10), as a pre-process, the positioning mechanism is driven to move the defect correction head unit relative to the substrate 2 placed on the Y-axis table 4. Then, a laser 8 is placed directly above the black defect observed using the observation optical system 6, and the black defect is irradiated with laser light to remove the resin material of the black defect and the surrounding color filter, and the laser. The cut part 310 (refer FIG.6 (b)) is formed.

  Next, in the step (S20), the ink application mechanism 9 is disposed immediately above the laser cut portion 310, and ink as a liquid material is applied to the laser cut portion 310 as a fine region on the substrate. FIG. 4A shows a state where the ink is filled in the laser cut part 310 and the ink application part 311 is formed. Ink of the same color as the pixel in which the laser cut portion 310 is formed (that is, the G pixel 302 in the case of FIG. 4A) is applied to the laser cut portion 310. In FIG. 4A, since the viscosity of the applied ink is high, the ink application part 311 does not reach the entire laser cut part 310, and the ink is applied in the vicinity of the corner of the rectangular laser cut part 310. No gap 312 is generated.

  Next, in the step (S30), the ink curing illumination 10 is disposed immediately above the ink application part 311. Then, the ink application part 311 is irradiated with light (ultraviolet light or halogen light) for curing the ink, the ink as the liquid material is dried, and the ink application part 311 is cured to such an extent that the ink can be plastically deformed.

  Next, in the step (S40), the pressurizing mechanism 11 is disposed immediately above the ink application unit 311. Here, as shown in FIG. 4B, the pressure head 21 is a thin film made of a resin material having a flat surface facing the substrate 2 and having excellent mechanical properties such as flex resistance, such as a polyimide film. It is coat | covered with the resin film 22. Then, the pressure head 21 is moved in the Z-axis direction perpendicular to the substrate 2 by driving a pressure head drive mechanism as a drive unit (not shown) to bring the pressure head 21 close to the substrate 2, and the Z-axis table 5. Thus, the pressure head 21 is further moved closer to the substrate 2 along the Z-axis direction. Then, as shown in FIG. 4C, the resin film 22 covering the flat surface is brought into contact with the ink application part 311 on the surface of the substrate 2.

  At this time, the flat surface of the pressure head 21 is shaped so as to be able to cover the entire laser cut portion 310 as a fine region, and covers the flat surface as shown in FIG. The pressure head 21 is moved so that the resin film 22 thus covered covers the entire laser cut portion 310. Then, the flat surface is pressed against the substrate 2 so that the flat surface of the pressure head 21 covers the entire laser cut portion 310. As a result, the ink applied to the laser cut portion 310 is pressed by the pressure head 21 while being confined in the space formed by the concave laser cut portion 310 and the flat surface. Pressed. The pressurized ink spreads over the entire laser cut unit 310, and the entire laser cut unit 310 is filled with ink. That is, as shown in FIGS. 4D and 4E, the gap 312 disappears after ink pressurization. Since the ink is uniformly pressurized in the entire laser cut portion 310, the thickness of the ink is made uniform. In other words, the ink can be leveled in the laser cut unit 310 by pressurizing the ink.

  The pressure head 21 is pressed against the substrate 2 with reference to a normal color filter surface. That is, as shown in FIG. 4C, when the ink is pressurized, the Z-axis direction of the pressure head 21 is such that the surface of the resin film 22 facing the substrate 2 is aligned with the normal color filter surface. Is controlled. In this way, the pressurized ink application part 311 is leveled with reference to the normal color filter surface as shown in FIG. That is, the thickness of the ink application part 311 can be made equal to the thickness of a normal color filter surface (G pixel 302 or the like).

  Here, since the flat surface of the pressure head 21 is covered with the resin film 22 and pressurizes the ink application part 311 through the resin film 22, it is possible to prevent ink from adhering to the pressure head 21. it can. Although the pressure head 21 may be brought into direct contact with the ink without providing the resin film 22 to pressurize the ink, the ink may adhere to the pressure head 21. When the ink adheres, the pressure head 21 needs to be cleaned, and it is difficult to clean it so that there is no residue each time. Therefore, it is more preferable to pressurize the ink application part 311 with the resin film 22 interposed therebetween. In this way, it is not necessary to clean the pressurizing head 21, and the process can be simplified. In addition, since the ink is hardened to such an extent that it can be plastically deformed in the previous step (S30), the ink is more difficult to adhere to the resin film 22. In the case where the ink adhesion to the resin film 22 during pressurization can be suppressed without causing a problem without precuring the ink, the step of curing the ink (S30) may be omitted.

  Returning to FIG. 3, in the next step (S <b> 50), the resin film 22 is moved relative to the pressure head 21. For example, a winding mechanism constituted by a supply reel and a winding reel can be provided. Then, the resin film 22 is formed in a tape shape, one end of the tape-shaped resin film 22 is fixed to the supply reel, the other end is fixed to the take-up reel, and the supply reel and the take-up reel are arbitrarily adjusted. Can be wound up and moved relative to the pressure head 21.

  By moving the resin film 22 relative to the pressure head 21, a portion different from the portion that covered the flat surface at the time of the step of pressurizing the resin film 22 (S40) covers the flat surface. . Therefore, even when ink as a liquid material adheres to the resin film 22 in the pressurizing step (S40), the resin film 22 that covers the pressurizing head 21 is replaced. It becomes possible to pressurize it in contact with. In addition, when ink is not adhering to the resin film 22, it is needless to say that this step (S50) may be omitted.

  Next, in a step (S60), as post-processing, the ink curing illumination 10 is disposed directly above the ink application unit 311 by driving the positioning mechanism, and the ink filled in the ink application unit 311 is cured by irradiation with light. Let As a result, the G pixel 302 having the same quality as the surrounding area is formed at the location where the black defect 305 has occurred, and the correction of the black defect 305 is completed.

  As described above, in this defect correction method, it is possible to level the thickness of the liquid material by uniformly pressurizing the liquid material such as ink in the entire laser cut portion 310 as a fine region. . There is no problem that the liquid material sticks out like the conventional method of re-applying the liquid material, or the color becomes too dark when the liquid material is ink. High-quality defect correction is possible without the problem of occurrence of bias. In the above description, the defect correction ink generated in the LCD color filter manufacturing process has been described as an example of the liquid material. However, the material to be applied is not limited to this, and the viscosity is high. If the material has poor fluidity, the defect correcting method of the present invention is applicable. For example, a gel-like soft semi-solid or solid material can be applied.

  The embodiment disclosed this time is to be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the whole structure of a defect correction apparatus. It is a block diagram which shows the component of a defect correction apparatus. It is a flowchart which shows the defect correction method. It is a schematic diagram which shows an ink pressurization process. It is a figure which shows the defect which generate | occur | produces in the manufacturing process of a color filter. It is a schematic diagram which shows the correction method of a black defect. It is a schematic diagram which shows the example of the ink application part before and behind air injection.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Defect correction apparatus, 2 board | substrate, 3 X-axis table, 4 Y-axis table, 5 Z-axis table, 6 Observation optical system, 7 CCD camera, 8 Laser, 9 Ink application mechanism, 10 Ink hardening illumination, 11 Pressurization mechanism , 12 control computer, 13 operation panel, 21 pressure head, 22 resin film, 121 air injection nozzle, 122 air flow, 300 black matrix, 301 R pixel, 302 G pixel, 303 B pixel, 304 white defect, 305 Black defect, 306 foreign object defect, 310 laser cut part, 311 ink application part, 312 gap, 313 ink bias.

Claims (5)

In a defect correction method for correcting a defect by applying a liquid material to a fine region on a substrate,
Applying the liquid material to the fine region;
Pressing the applied liquid material by pressing a pressure head having a flat surface facing the substrate against the substrate such that the flat surface covers all of the fine regions. Defect correction method.   The defect correction method according to claim 1, wherein in the pressing, the flat surface is covered with a resin film.   After the pressurizing step, the resin film is applied to the pressurizing head such that a portion of the resin film that is different from the portion that covered the flat surface at the time of the pressurizing step covers the flat surface. The defect correction method according to claim 2, further comprising a step of relatively moving with respect to the defect.   The defect correction method according to claim 1, further comprising a step of curing the liquid material between the applying step and the pressing step. A defect correction apparatus for use in the defect correction method according to any one of claims 1 to 4,
An application mechanism for applying a liquid material to a fine region on the substrate;
A pressure head having a flat surface facing the substrate;
A drive unit that moves the pressure head in a direction that intersects the surface of the substrate;
The defect correction apparatus, wherein the orthogonal projection of the flat surface onto the substrate can cover and hide the entire fine region.

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