JP4617236B2 - How to correct the color filter - Google Patents

Description

  The present invention is a display used for a color display panel such as a color filter used in a liquid crystal panel, a plasma panel, a micromirror panel, a cathode ray tube display, a projection television, and a light emitting layer colored part such as a display using an EL material. The present invention relates to a method for correcting colored parts for elements.

Colorized parts for display elements consist of R (red), G (green), B (blue), and BM (black) regions. The printing method, electrodeposition method, pigment dispersion method by photolithography, R, G by inkjet method. , B and BM patterns can be formed.
The printing method is inferior to other methods in terms of pattern accuracy, and is rarely used in the current display element formation process.
The electrodeposition method is a method using a colored ink having conductivity. Since the color purity of the conductive ink is low, there is a problem that vivid color display is difficult and the commercial value is low.

The pigment dispersion method by photolithography is the most widely used method at present, but it requires at least three times of photolithography to form R, G, B, and BM. There's a problem.
The inkjet method has recently attracted attention as a method that can improve pattern accuracy, improve color purity, and reduce manufacturing costs. However, when ink is applied (applied) with high accuracy, it mixes with adjacent pixels and displays quality. There is a problem that decreases.
Further, even if any of the above methods is used, it is difficult to manufacture a colored part for a display element as a 100% non-defective product, and there are defects due to foreign matters, defects in R, G, B, and BM patterns. appear.

  In view of this, a method for correcting defects by ink jet has been proposed (see, for example, Japanese Patent Laid-Open No. 11-271752 (Patent Document 1)).

Japanese Patent Laid-Open No. 11-271752

  Conventionally, various methods have been proposed and put to practical use for correcting defects in color filters using the ink jet method. However, in those methods, when the defect such as foreign matter or color loss is corrected, the ink overflows to the adjacent pixel portion in a normal state, or a protrusion is formed in the corrected pixel portion because the ink viscosity is high, Defects such as electrical short-circuiting with the counter electrode at the correction location frequently occurred.

On the other hand, a method has been proposed in which a difference in liquid repellency or lyophilicity is provided on a substrate serving as a pixel area so that ink is applied only to a predetermined pixel area.
In the water repellent treatment, for example, liquid repellency is imparted to the substrate surface by plasma treatment of carbon tetrafluoride or dicarbon hexafluoride. However, since carbon tetrafluoride has a warming coefficient 6300 times that of carbon dioxide, it cannot be opened to the atmosphere, and an expensive carbon tetrafluoride decomposition facility is required, which occurs during processing. This method is not preferable from the viewpoint of production cost because it requires expensive detoxification equipment for harmful gases.

There are also water-repellent treatments such as spin coating and vacuum plasma treatment, but these impart liquid repellency to the entire surface of the substrate, requiring a large-scale facility, and this method is also not preferable in terms of manufacturing cost. .
Furthermore, these methods also have a problem in that the ink overflows from the corrected portion, and correction failures occur frequently, so that the yield is difficult to improve.

  The present invention solves such a problem, and corrects defects in colored parts for display elements by an ink-jet method using inexpensive and highly versatile materials that eliminate the failure of correction and achieve a high correction success rate. It is an object to provide a method.

Thus, according to the present invention, in correcting the defects present in the colored layer of the colored component for display elements used in the color display panel,
(A) detecting defects present in the colored layer ;
(B) The detected defect is removed by laser irradiation or not,
(C) A coating agent containing an acrylic resin, a fluorosurfactant, and a solvent is applied to the removed defect and its periphery, or the defect that has not been removed and its periphery by an inkjet method,
(D) removing the missing Ochiima other was leaving coating agent around the defect was not removed, was or coating agent to remove the coating agent and the defect by laser irradiation,
(E) The ink for the colored layer is applied to the removed portion by an inkjet method,
Provided is a method for correcting a defect in a colored part for a display element, wherein the defect is corrected.

  According to the present invention, since it is inexpensive and eliminates the failure of correction and a high correction success rate can be realized, the yield of colored parts for display elements can be improved.

Unlike the prior art in which ink is applied to a defect or a portion from which the defect has been removed, the defect correcting method for a colored component for display elements according to the present invention is applied to a defect that has been removed and its periphery, or a defect that has not been removed and its periphery The coating agent is applied by the inkjet method (step (C)), and the coating agent around the removed defect or the coating agent around the defect that has not been removed is left, and the coating agent or the coating agent is irradiated by laser irradiation. The defect is removed (step (D)), and ink is applied to the removed portion.
That is, the present invention realizes a high success rate in correcting defects present in the colorized parts for display elements by the steps (C) and (D).
The coating agent will be described in detail in Embodiment 1.

  Embodiments of the present invention will be described with reference to the drawing of a color filter of a display element substrate. However, these embodiments are merely examples, and various forms can be implemented within the scope of the present invention.

FIG. 1 is a schematic top view (a) and a schematic cross-sectional view (A) taken along line A-A, showing defects in the color filter of the display element substrate.
As shown in FIG. 1, the color filter is formed by regularly and precisely patterning a red portion 2, a green portion 3, a blue portion 4, and a black matrix portion 5 on a substrate 1 (for example, a glass substrate). ing. The size of each picture element of red, blue, and green is about 100 μm, and the width of the black matrix portion is often 50 μm or less, although it varies depending on conditions such as the use of the display element and the manufacturing apparatus. If such a regular pattern is disturbed even at one place, the display quality of the panel is lowered, and in many cases, the panel itself becomes a defective product and has no commercial value.
Disturbances (defects) in the pattern occur in the manufacturing process, and main defects include color part pinholes ("color loss" 7) caused by adhesion of foreign matter 6, exposure failure or physical contact, and black matrix part pins. Holes (“white spots” 8), color mixture other than the purpose (“other color filling” 9), and the like can be mentioned.
In the present specification, each of the red portion 2, the green portion 3, and the blue portion 4 is referred to as “picture element”, and a set of these is referred to as “pixel”.

FIG. 2 is a schematic cross-sectional view showing a defect correcting method for a colored part for display element according to the present invention, and shows a state of ink application in each embodiment described later.
As shown in FIG. 2, the laser device 11, the inkjet head 16, and the drying lamp 12 can freely operate so that the substrate 1 of the color filter having the defect of FIG. It is connected and fixed to the XYZ stage 13. In FIG. 2, the ink 10 is about to be applied to the portion of the other color filling 9. Numbers 2 to 8 are the same as those in FIG.

(Embodiment 1)
This embodiment is a defect correction method in the case where foreign matter is attached as a defect to the color filter.
If foreign matter adheres to the color filter, the picture element may appear black or shine in reverse, which is corrected in this embodiment.
FIG. 3 is a schematic top view (on the left side) showing the steps of this embodiment and a schematic cross-sectional view at AA (on the right side).
The figure numbers in the figure are the same as those in FIG. 1, 1 is a substrate, 2 is a red part (R), 4 is a blue part (B), 5 is a black matrix part, and 6 is a foreign substance.

Process (A)
First, as shown in FIG. 3A, the foreign material 6 present in the color filter is detected, and its position and size are confirmed.
Examples of the defect detection method include known inspection apparatuses such as a pattern inspection apparatus, a visual inspection apparatus, and a height inspection apparatus. In order to further improve the detection accuracy, the detected foreign matter may be confirmed by microscopic observation or visual observation.

Process (B)
Next, as shown in FIG. 3B, the detected defect is removed by laser irradiation. Specifically, using a known laser apparatus 11 as shown in FIG. 2, a defect and a part or all of the colored layer including the defect are removed by laser irradiation.
Laser irradiation conditions may be set as appropriate depending on the physical properties of the colored layer to be removed.
If the defect (foreign matter) removed in this process is left as it is, the color loss 7 as shown in FIG. 1 occurs and the picture element appears to shine, so the color filter becomes a defective product having no commercial value.

Process (C)
Next, as shown in FIG.3 (c), a coating agent is apply | coated to the removed defect and its periphery with an inkjet system, and a coating agent is dried as needed. Specifically, using a known inkjet head 16 as shown in FIG. 2, a coating agent 15 is applied so as to cover the area removed by laser irradiation, and as shown in FIG. 2, if necessary. The coating agent is dried using such a known drying lamp 12.
As described above, although it varies depending on the physical properties of the coating agent, it is preferable to perform heat treatment for drying or resin curing after application of the coating agent in the step (C), if necessary.

  When the shape of the coating agent after drying becomes a lens shape, light may be refracted and appear dark like a stain when the color display panel is a gray screen. Also, it may appear shining depending on the light level. For this reason, it is preferable to keep the area and film thickness on which the coating agent 15 is applied to the minimum at which liquid repellency can be obtained, and the film thickness is preferably 2 μm or less.

  Examples of the coating agent coating method include a coating method using an inkjet head, a method of transferring the coating agent at the tip of the needle onto the substrate, a method called a needle type that pushes out and applies the needle, and among these, the inkjet method is used. A coating method using a head is particularly preferable.

The coating agent is highly transparent and needs to transmit light efficiently.
Therefore, the coating agent is preferably a coating solution containing a resin having a light transmittance of a wavelength of 400 to 700 × 10 ⁻⁹ m, a surfactant and a solvent.
Examples of such resins include acrylic resins, nylon resins, polyimide resins, and epoxy resins, and these can be used preferably.

In addition, it is preferable that the coating agent has a surface that is difficult to adjust to the ink 10 to be applied later, because the ink can be prevented from overflowing to adjacent picture elements.
Further, when the coating agent is applied by an ink jet method, it needs to have a surface tension and a viscosity within a range that does not adversely affect the ink jet head.
Therefore, the coating agent has a surface tension of 10 to 100 mN / m, preferably 20 to 40 mN / m and a viscosity of 0.5 to 50 Pa · s, preferably 5 to 10 Pa · s, and is a dry coating agent. It is preferable that the contact angle when the ink is dropped by 10 μl on the surface is 20 ° or more, preferably 50 ° or more.

In order to obtain such a coating agent, the type and addition amount of the surfactant may be appropriately set. As the surfactant, in the case of an acrylic resin, for example, a fluorosurfactant may be used.
Also, the drying rate of the coating agent is important, and this can be adjusted by setting the type and amount of the solvent.
If the drying rate of the coating agent is fast, that is, if the evaporation rate of the solvent is fast, the solid content is fixed on the surface of the ink jet head, and it may not be possible to operate the ink jet for a long time. As a solvent, when it is acrylic resin, BCTAC, PEGMEA, etc. are mentioned, for example.

  Before applying the coating agent in the step (C), it is preferable to apply a small amount of colored layer ink to the removed defects. This is preferable because the removal efficiency of the coating agent by laser irradiation in the next step (D) is improved.

Process (D)
Next, as shown in FIG. 3D, the coating agent is removed by laser irradiation while leaving the coating agent around the removed defect. Specifically, using a known laser device 11 as shown in FIG. 2, when the coating agent and further the ink are applied, the ink layer is removed by laser irradiation.
What is necessary is just to set suitably the irradiation conditions of a laser with the physical property of the coating agent to remove.

Process (E)
Next, as shown in FIG. 3E, a colored layer ink (here, red ink) is applied to the portion from which the coating agent has been removed by an inkjet method. Specifically, using a known inkjet head 16 as shown in FIG. 2, the ink 10 is applied to the portion from which the coating agent has been removed, and if necessary, a known drying as shown in FIG. The ink is dried using the lamp 12.
As described above, although it varies depending on the physical properties of the ink, it is preferable to perform heat treatment for drying or resin curing after application of the colored layer (or light emitting layer) in the step (E) as necessary.
However, when discoloration of the colorant due to heat becomes a problem, it is preferable not to heat.

  The ink to be applied is the ink used in the manufacture of the color filter or an equivalent ink, and when applied by the ink jet method, the surface tension and the viscosity should be adjusted within a range that does not adversely affect the ink jet head. preferable.

As described above, when the defect is a foreign substance, it is preferable to remove the defect in the step (B).
However, in the case where the state of the foreign matter is as follows, the defect is not removed in the step (B), the coating agent is applied with the foreign matter attached (step (C)), and the defect that has not been removed is removed. You may remove a coating agent with a foreign material, leaving the surrounding coating agent.
(1) When the foreign matter 6 is too large for the laser irradiation area irradiated from the laser device 11 and the defect correction is not finished in the series of processes as described above. (2) For the spread range of the coated coating agent 15 When the foreign matter 6 is small and does not affect the wet spread of the coating agent 15

(Embodiment 2)
This embodiment is a defect correction method when another color filling 9 occurs as a defect in the color filter.
Other than the target color in the color filter, for example, when other color filling occurs so that the red portion 2 is mixed with the blue portion 4, the picture element may appear black or may change to an unintended color tone. This embodiment corrects this. .
FIG. 4 is a schematic top view (left side) showing a process of this embodiment and a schematic cross-sectional view (right side) taken along line AA.
The figure numbers in the figure are the same as those in FIG. 1, 1 is a substrate, 3 is a green part (G), 4 is a blue part (B), 5 is a black matrix part, and 9 is filled with other colors.

Step (A)
First, as shown in FIG. 4A, the other color block 9 existing in the color filter is detected, and its position and size are confirmed. The details are the same as in step (A) of the first embodiment.

Process (C)
Next, as shown in FIG. 4B, a coating agent is applied by an ink jet method so as to cover the defect and its periphery, that is, the range of the other color filling 9, and the coating agent 15 is dried as necessary. . The details are the same as in step (C) of the first embodiment.

Process (D)
Next, as shown in FIG. 4C, the coating agent and the defect are removed by laser irradiation while leaving the coating agent around the defect. The details are the same as in step (D) of the first embodiment.

Process (E)
Next, as shown in FIG. 4D, blue ink is applied to the portion from which the coating agent has been removed by an inkjet method. The details are the same as in step (E) of the first embodiment.

  When the other color filling is too large with respect to the laser irradiation area irradiated from the laser device 11, and the defect correction is not finished in the series of processes as described above, the coating agent is removed by laser irradiation (process (D)). ) And application of the colored layer or light emitting layer ink (step (E)) may be carried out a plurality of times. Thereby, a large defect area can be corrected.

When the steps (D) and (E) are repeated a plurality of times in this way, when the ink is applied in the step (E), if there is no coating agent on at least three sides of the application region, the applied ink overflows. Sometimes.
Therefore, when the steps (D) and (E) are repeated twice, it is preferable that the first and second application regions are overlapped, for example, as shown in FIG. 4 (e).
In particular, when colored parts for display elements are high value-added products and the quality of defect correction is questioned, when applying ink by repeating all the steps instead of repeating steps (D) and (E) In addition, it is preferable to apply the ink in a state where the entire side (the entire circumference) is surrounded by the coating agent.

Although depending on the physical properties of the coating agent and ink, if an amount of ink necessary for correction is applied to the portion where the coating agent has been removed at once, the ink overflows and defect correction may fail.
Therefore, when the defect exists in the red part, the green part, or the blue part of the colored component for display element, the ink application in step (E) is performed by applying any one of the inks selected from red, green, and blue. It is preferable to carry out by overlapping.

(Embodiment 3)
This embodiment is a defect correction method when the color loss 7 exists as a defect in the color filter.
If there is a color loss without a color portion in the color filter, the picture element may appear shining, which is corrected in this embodiment.
FIG. 5 is a schematic top view (on the left side) showing the steps of this embodiment and a schematic cross-sectional view at AA (on the right side).
The figure numbers in the figure are the same as those in FIG. 1, 1 is a substrate, 3 is a green part (G), 4 is a blue part (B), 5 is a black matrix part, and 7 is a missing color.

Process (A)
First, as shown in FIG. 5A, the color loss 7 existing in the color filter is detected, and its position and size are confirmed. The details are the same as in step (A) of the first embodiment.

Process (C)
Next, as shown in FIG. 5C, a coating agent is applied by an inkjet method so as to cover the defective portion and its periphery, that is, the range of the color loss 7, and the coating agent 15 is dried as necessary. . The details are the same as in step (C) of the first embodiment.

As shown in FIG. 5B, it is preferable to apply a small amount of colored layer ink to the defect before applying the coating agent in the step (C). This is preferable because the removal efficiency of the coating agent by laser irradiation in the next step (D) is improved. If a small amount of ink is not applied, the substrate and the coating agent may be in direct contact, and the coating agent may not be removed by laser irradiation.
Even when a small amount of ink is not applied, the coating agent may be removed by increasing the intensity of laser irradiation. Therefore, when the laser intensity is sufficient, it is preferable to increase the laser intensity without applying ink because the processing time is shortened.

Process (D)
Next, as shown in FIG. 4D, the coating agent is removed by laser irradiation while leaving the coating agent around the defect. This is the same as step (D) in the first embodiment.

Process (E)
Next, as shown in FIG.5 (e), green ink is apply | coated to the part from which the coating agent was removed by the inkjet system. The details are the same as in step (E) of the first embodiment.

  When the color loss is too large for the laser irradiation area irradiated from the laser device 11 and the defect correction is not completed in the series of processes as described above, the coating agent is removed by laser irradiation (process (D)). Application of the colored layer or light emitting layer ink (step (E)) may be performed a plurality of times. Thereby, a large defect area can be corrected.

When the steps (D) and (E) are repeated a plurality of times in this way, when the ink is applied in the step (E), if there is no coating agent on at least three sides of the application region, the applied ink overflows. Sometimes.
In particular, when colored parts for display elements are high value-added products and the quality of defect correction is questioned, when applying ink by repeating all the steps instead of repeating steps (D) and (E) In addition, it is preferable to apply the ink in a state where the entire side (the entire circumference) is surrounded by the coating agent.

(Embodiment 4)
This embodiment is a defect correction method in the case where white spots 8 exist as defects in the color filter.
If there are white spots 8 that do not have a black matrix portion in the color filter, the picture elements may appear shining, which is corrected in this embodiment.
FIG. 6 is a schematic top view (on the left side) showing the steps of this embodiment and a schematic cross-sectional view (on the right side) along AA.
The figure numbers in the figure are the same as those in FIG. 1, 1 is a substrate, 2 is a red part (R), 4 is a blue part (B), 5 is a black matrix part, and 8 is white.

Process (A)
First, as shown in FIG. 6A, the white spot 8 existing in the color filter is detected, and its position and size are confirmed. The details are the same as in step (A) of the first embodiment.

Process (C)
Next, as shown in FIG. 6C, a coating agent is applied by an ink jet method so as to cover the defective portion and its periphery, that is, the range of the white spots 8, and the coating agent 15 is dried as necessary. . The details are the same as in step (C) of the first embodiment.

As shown in FIG. 6B, it is preferable to apply a small amount of colored layer ink to the defects before applying the coating agent in the step (C). This is preferable because the removal efficiency of the coating agent by laser irradiation in the next step (D) is improved. If a small amount of ink is not applied, the substrate and the coating agent may be in direct contact, and the coating agent may not be removed by laser irradiation.
Even when a small amount of ink is not applied, the coating agent may be removed by increasing the intensity of laser irradiation. Therefore, when the laser intensity is sufficient, it is preferable to increase the laser intensity without applying a small amount of ink because the processing time is shortened.

Process (D)
Next, as shown in FIG. 6D, the coating agent is removed by laser irradiation while leaving the coating agent around the defect. The details are the same as in step (D) of the first embodiment.

Process (E)
Next, as shown in FIG. 6E, blue ink and red ink are sequentially applied to the portion from which the coating agent has been removed by an inkjet method. The details are the same as in step (E) of the first embodiment. The order of ink application is not particularly limited, and blue and red may be reversed.

  When the blank area is too large for the laser irradiation area irradiated from the laser device 11 and defect correction is not completed in the series of processes as described above, the coating agent is removed by laser irradiation (process (D)). Application of the colored layer or light emitting layer ink (step (E)) may be performed a plurality of times. Thereby, a large defect area can be corrected.

When the steps (D) and (E) are repeated a plurality of times in this way, when the ink is applied in the step (E), if there is no coating agent on at least three sides of the application region, the applied ink overflows. Sometimes.
In particular, when colored parts for display elements are high value-added products and the quality of defect correction is questioned, when applying ink by repeating all the steps instead of repeating steps (D) and (E) In addition, it is preferable to apply the ink in a state where the entire side (the entire circumference) is surrounded by the coating agent.

  When a defect exists in the black matrix portion of the colorization part for display element, it is preferable to apply the ink in the step (E) by applying a plurality of colors of ink selected from red, green, and blue. Thus, by replacing the ink coating with the application of the black ink, the inkjet head for the black ink becomes unnecessary, and the cost of defect correction can be reduced.

The defect correction method for colored parts for display elements of the present invention can be applied when there is at least one defect selected from foreign matter, other color filling, color loss and white loss, and multiple defects are detected on the same substrate. In such a case, the series of steps as described above may be carried out simultaneously or repeatedly.
In addition, if the color of the ink to be applied is wrong in step (E), the wrong ink can be removed by laser irradiation in the same manner as in step (B) to bring it closer to the state before step (E). Can do.

It is the model top view (a) which shows the defect of the color filter of a display element substrate, and the schematic cross section (b) in AA. It is a schematic cross section which shows the defect correction method of the colored component for display elements of this invention. It is the model top view (left side) which shows the defect correction method (embodiment 1) of the coloration components for display elements of this invention, and the schematic cross section in the AA (right side). It is the model top view (left side) which shows the defect correction method (Embodiment 2) of the colorization components for display elements of this invention, and the schematic cross section in the AA (right side). It is the model top view (left side) which shows the defect correction method (embodiment 3) of the colorization components for display elements of this invention, and the schematic cross section in the AA (right side). It is the model top view (left side) which shows the defect correction method (Embodiment 4) of the colorization components for display elements of this invention, and the schematic cross section in the AA (right side).

Explanation of symbols

1 Substrate (glass substrate)
2 Red part (R)
3 Green part (G)
4 Blue part (B)
5 Black matrix portion 6 Foreign matter 7 Color loss 8 White color loss 9 Other color filling 10 Ink 11 Laser device 12 Drying lamp 13 XYZ stage 14 Stage 15 Coating agent 16 Inkjet head

Claims (7)

In correcting defects present in the colored layer of the colored parts for display elements used in color display panels,
(A) detecting defects present in the colored layer ;
(B) The detected defect is removed by laser irradiation or not,
(C) A coating agent containing an acrylic resin, a fluorosurfactant, and a solvent is applied to the removed defect and its periphery, or the defect that has not been removed and its periphery by an inkjet method,
(D) removing the missing Ochiima other was leaving coating agent around the defect was not removed, was or coating agent to remove the coating agent and the defect by laser irradiation,
(E) The ink for the colored layer is applied to the removed portion by an inkjet method,
A defect correction method for a colored part for a display element, wherein the defect is corrected.   The defect correction method according to claim 1, wherein the defect is at least one selected from foreign matter, other color filling, color loss, and white loss.   The defect correction method according to claim 1 or 2, wherein the defect is removed in the step (B) when the defect is a foreign matter. The defect correction method according to any one of claims 1 to 3, wherein the colored layer ink is applied to the removed defect or the defect that has not been removed before the coating agent is applied in the step (C).   The defect correction method according to any one of claims 1 to 4, wherein a heat treatment for drying or resin curing is performed after the coating agent is applied in step (C) and / or after the ink is applied in step (E).   When the defect exists in the red part, the green part, or the blue part of the colored component for display element, the ink application in the step (E) is performed by applying one of the inks selected from red, green, and blue. The defect correction method according to claim 1, wherein the defect correction method is performed.   The ink application in the step (E) is performed by applying a plurality of colors of ink selected from red, green, and blue when a defect exists in the black matrix portion of the colored component for display element. The defect correction method as described in any one of these.

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