JP5619143B2 - Liquid crystal panel manufacturing method, liquid crystal panel and repair device - Google Patents

Description

The present invention relates to a method for manufacturing a liquid crystal panel, a liquid crystal panel, and a repair device. In particular, the present invention relates to a technique for repairing an alignment film of a liquid crystal panel.
This application claims priority based on Japanese Patent Application No. 2010-88341 filed on Apr. 7, 2010, the entire contents of which are incorporated herein by reference. .

  A liquid crystal panel, which is a component of a liquid crystal display device, has a structure in which a pair of substrates are opposed to each other with a predetermined gap secured. A liquid crystal layer containing liquid crystal molecules is sealed in the gap between the substrates. In addition, an alignment film for regulating the alignment state of the liquid crystal molecules is formed on the surfaces of both substrates in contact with the liquid crystal layer (for example, Patent Document 1).

In this alignment film, local pinholes may occur due to the following circumstances.
(1) Foreign matter mixed in the alignment film forming process adheres, and the alignment film is locally cut off as the foreign matter is removed, thereby generating a pinhole.
(2) The adhesion of the alignment film to the underlying layer (pixel electrode or counter electrode) is locally poor, and the alignment film material is repelled at the time of film formation, resulting in pinholes.
(3) When a material that vertically aligns liquid crystal molecules is used as the alignment film material, the sticking property of the alignment film to the underlying layer tends to deteriorate, and pinholes are likely to occur in combination with (2) above.
(4) If the alignment state of the liquid crystal molecules is regulated by forming recesses or protrusions on the base of the alignment film and providing a step on the surface of the alignment film, the laying area of the alignment film on the base increases. In combination with (2), pinholes are likely to occur.

  When pinholes are generated in the alignment film due to the above-described circumstances, an image is not normally displayed at that portion. Therefore, depending on the size or formation position of the pinhole, there arises a problem that the alignment film must be completely peeled off and the film is formed again, resulting in an increase in manufacturing cost.

  According to the technique disclosed in Patent Document 1, after detecting a pinhole in the alignment film, a stamp method is proposed in which the alignment film repair agent is transferred to the pinhole. According to this stamp method, the pinhole is repaired by pressing the transfer head with the alignment film repairing agent against the pinhole, so that the repair can be easily performed and the thickness of the repaired part can be controlled. Can be easily performed.

International Publication WO2007-132586

  When the stamp method disclosed in Patent Document 1 is used, locally generated pinholes can be easily repaired. However, according to the study of the present inventors, it has been found that the repair cannot be performed satisfactorily depending on the combination (compatibility) of the alignment film and the alignment film repair agent. Specifically, even when repairing a certain alignment film satisfactorily, it was observed that the alignment film could not be repaired satisfactorily when the type of the alignment film (material, product number, etc.) was changed. The reason why it cannot be repaired well, even by experts, is often not immediately obvious, and therefore it is difficult to find an alignment film repair agent that can be easily repaired to a modified alignment film by trial and error. Will do.

  In addition, as a method for forming the alignment film, there is an ink jet method in addition to a spin coating method and a spray method. When the alignment film is formed by the inkjet method, the coating liquid may not be ejected from the nozzles of the inkjet head, and in that case, a relatively wide pinhole (defect due to defective nozzle ejection) may occur. . And such pinholes need repair, and further improvement of pinhole repair technology is required.

  This invention is made | formed in view of this point, The main objective is to provide the manufacturing method of the liquid crystal panel which can repair the defect of alignment film more easily.

The method for producing a liquid crystal panel according to the present invention includes a step of forming an alignment film on the surface of the substrate by discharging a coating liquid by an ink jet method, and a step of repairing a defective portion of the alignment film by applying a repair ink. The coating solution in the step of forming the alignment film includes a solid content made of a material constituting the alignment film, a strong solvent that dissolves the solid content, and a dissolution in the solid content rather than the strong solvent. And the repair ink has a solid content concentration (mass%) lower than the solid content concentration (mass%) contained in the coating liquid, and the repair ink. Comprises a solid solvent, a strong solvent that dissolves the solid content, a weak solvent that is less soluble in the solid content than the strong solvent, and a low surface tension agent that reduces the contact angle of the repair ink. .
In a preferred embodiment, the solid concentration of the repair ink is 1/10 or less of the solid concentration of the coating liquid.
In a preferred embodiment, the solvent ratio of the strong solvent in the repair ink is lower than the solvent ratio of the strong solvent in the coating liquid.
In a preferred embodiment, the solvent ratio of the strong solvent to the weak solvent (strong solvent: weak solvent) in the coating solution is 50:50.
In a preferred embodiment, the low surface tension agent is a liquid, and the ratio of strong solvent, weak solvent, and low surface tension agent (strong solvent: weak solvent: low surface tension agent) in the correction ink is 30: 50:20.
The liquid crystal panel according to the present invention is a liquid crystal panel including a pair of substrates facing each other and a liquid crystal layer disposed between the pair of substrates, and the surface of the substrate in contact with the liquid crystal layer is aligned. A film is formed, and a repair layer is formed at a defect portion of the alignment film. The alignment film is formed by discharging a coating liquid by an ink jet method, and the repair layer is repaired. The coating liquid is formed by applying ink, and the coating liquid has a solid content made of a material constituting the alignment film, a strong solvent that dissolves the solid content, and a solubility in the solid content rather than the strong solvent. The repair ink has a solid content concentration lower than the solid content concentration contained in the coating liquid, and the repair ink comprises the solid content and the solid content. Strong dissolution to dissolve If, comprising a weak solvent with poor solubility in the solid content than the strong solvent and a low surface tension agent to reduce the contact angle of the repair ink.
A repair device according to the present invention is a device for repairing a defective portion of an alignment film, and includes a repair stamp, a moving device that moves the repair stamp, and a control device that controls the moving device, and the control device includes: Moving the repair stamp to an ink supply unit that supplies repair ink, and disposing the repair stamp in a region including the defect portion of the alignment film. The alignment film is formed by discharging a coating liquid by an ink jet method, and the coating liquid includes a solid content made of a material constituting the alignment film, and a strength that dissolves the solid content. A solvent and a weak solvent that is less soluble in the solid content than the strong solvent, and the repair ink is lower than the concentration of the solid content contained in the coating solution The repair ink has a solid content, the solid content, a strong solvent that dissolves the solid content, a weak solvent that is less soluble in the solid content than the strong solvent, and the repair ink. And a low surface tension agent that lowers the contact angle.
In a preferred embodiment, an inspection apparatus for inspecting a defective portion of the alignment film is further provided.

  According to the present invention, after forming the alignment film on the surface of the substrate by ejecting the coating liquid by an ink jet method, the defect portion of the alignment film can be repaired by applying the repair ink. The coating liquid contains a solid content made of the material constituting the alignment film, a strong solvent that dissolves the solid content, and a weak solvent, while the repair ink is lower than the solid content concentration of the coating liquid. The restoration ink has a solid concentration and contains a low surface tension agent that reduces the contact angle. Therefore, the contact angle of the repair ink can be reduced. Therefore, it is possible to suppress the occurrence of a protrusion (periphery) at a position located at the periphery of the repair ink. As a result, it becomes possible to repair defects in the alignment film more easily.

It is sectional drawing of the liquid crystal display device 100 provided with the liquid crystal panel 10 which concerns on embodiment of this invention. 3 is an enlarged plan view of a part of the upper surface of the array substrate 12. FIG. 2 is an enlarged cross-sectional view of a part of the liquid crystal panel 10. FIG. 4 is a plan view of a part of the upper surface of the array substrate 12. FIG. (A) to (c) are process cross-sectional views for explaining the process of forming the repair layer 35. (A) is a figure which shows the mode of the board | substrate after a repair with a repair ink, (b) is an enlarged view of the repair area | region 57. FIG. (A) to (c) are process cross-sectional views for explaining how the peripheral edge (projection) 35b of the repair layer 35 is formed. (A) to (c) are process cross-sectional views for explaining the process of forming the repair layer 35. 1 is a plan view showing a configuration of an inkjet type coating apparatus 200. FIG. 1 is a plan view showing a configuration of an inkjet type coating apparatus 200. FIG. It is a figure which shows the structure of the coating device 200 of an inkjet system. It is a figure which shows typically the structure of the repair apparatus 300 which concerns on embodiment of this invention. It is a block diagram which shows the structure of the repair apparatus 300 which concerns on embodiment of this invention. It is a top view of a part of upper surface of the array substrate 12 including a plurality of repair regions.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, components having substantially the same function are denoted by the same reference numerals for the sake of brevity. In addition, this invention is not limited to the following embodiment.

  First, a liquid crystal display device 100 including a liquid crystal panel 10 obtained by a manufacturing method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

  FIG. 1 schematically shows a cross-sectional configuration of a liquid crystal display device 100 including a liquid crystal panel 10 of the present embodiment. A liquid crystal display device 100 shown in FIG. 1 includes a liquid crystal panel 10 and a backlight 20 that is an external light source disposed on the back side (lower side in FIG. 1) of the liquid crystal panel. The liquid crystal panel 10 and the backlight 20 are assembled and held by a bezel 29 covered from the front side of the liquid crystal panel 10.

  The backlight 20 includes a plurality of linear light sources (for example, cold cathode tubes) 22 and a case 24 that houses the light sources 22. The case 24 has a box shape opened toward the front side (the liquid crystal panel 10 side), and the linear light sources 22 are arranged in parallel in the case 24. Note that the backlight 20 is not limited to a linear light source, but may have another configuration (for example, an LED light source).

  A plurality of optical sheets 26 are stacked and arranged in the opening of the case 24. The optical sheet 26 includes, for example, a diffusion plate, a diffusion sheet, a lens sheet, and a brightness enhancement sheet in order from the back side. Further, in order to hold the optical sheet 26 between the case 24 and the case 24, a substantially frame-like frame 28 is provided on the case 24.

  The liquid crystal panel 10 generally has a rectangular shape as a whole, and is composed of a pair of translucent substrates (glass substrates) 11 and 12. Both substrates 11 and 12 are cut from a large base material called mother glass in the manufacturing process.

  Both the substrates 11 and 12 are arranged to face each other, and a liquid crystal layer 13 is provided therebetween. The liquid crystal layer 13 is made of a liquid crystal material whose optical characteristics change with application of an electric field between the substrates 11 and 12. A sealing material 15 is provided on the outer edge portions of the substrates 11 and 12 to seal the liquid crystal layer 13. A gap between the substrate 11 and the substrate 12 is secured by a spacer (not shown) and the sealing material 15. The spacers are made of, for example, an elastically deformable resin and have a granular shape (spherical shape). A large number of spacers are dispersed at predetermined positions in the liquid crystal layer 13. Further, polarizing plates 17 and 18 are attached to the outer surfaces of both substrates, respectively. The spacer is not limited to a granular structure, and may be a columnar spacer.

  In the present embodiment, among the substrates 11 and 12, the front side is the color filter substrate (CF substrate) 11, while the back side is the array substrate 12. FIG. 2 shows an enlarged part of the upper surface of the array substrate 12. FIG. 3 shows an enlarged part of the cross section of both the substrates 11 and 12.

  As shown in FIG. 2, switching elements (for example, TFTs) 44 and pixel electrodes 46 are provided on the upper surface of the array substrate 12 (the liquid crystal layer 13 side and the opposite surface side of the CF substrate 11). Around the switching element 44 and the pixel electrode 46, a grid-like source wiring 41 and gate wiring 42 are provided so as to surround them. The source wiring 41 and the gate wiring 42 are connected to the source electrode and the gate electrode of the switching element 44, respectively. The pixel electrode 46 is made of, for example, ITO (indium tin oxide). For example, the pixel electrode 46 is formed in a rectangular shape, and in the example illustrated in FIG. 2, the pixel electrode 46 is formed in an elongated rectangular shape along the direction in which the source wiring 41 extends.

  In the present embodiment, as shown in FIG. 3, the gate wiring 42 is formed on the array substrate (specifically, the glass substrate) 12. An insulating layer 31 is formed on the array substrate 12 so as to cover the gate wiring 42. An insulating layer 32 is formed on the insulating layer 31, and a pixel electrode 46 is formed on the insulating layer 32. The substrate 12 to the insulating layer 32 and the pixel electrode 46 may be referred to as the array substrate 12.

  On the pixel electrode 46 and the insulating layer 32, an alignment film 30 (30A) for aligning liquid crystal molecules in the liquid crystal layer 13 is formed. In other words, the alignment film 30 (30A) is formed on the surface in contact with the liquid crystal layer 13 in the pixel electrode 46 and the insulating layer 32 located outside thereof. The alignment film 30 of the present embodiment is made of a material (so-called vertical alignment type material) that aligns liquid crystal molecules perpendicularly to the surface of the alignment film 30 in a state where no voltage is applied to the liquid crystal layer 13. The The alignment film 30 of this embodiment is made of polyimide. The thickness of the alignment film 30 is, for example, about 100 nm to 200 nm. In the present embodiment, the pixel electrode 46 and the insulating layer 32 are the base of the alignment film 30. However, in a liquid crystal panel employing another laminated structure, a layer different from the above may be the base.

  The pixel electrode 46 (surface of the array substrate 12) of the present embodiment is provided with slits 33 (grooves, openings, steps). Therefore, a step is generated on the surface of the alignment film 30 formed along the pixel electrode 46. In this example, as shown in FIG. 2, the slit 33 is formed in a groove shape having a predetermined width. Specifically, the pixel electrode 46 is formed at the center position in the longitudinal direction, in the vicinity of both end positions in the longitudinal direction, and at an intermediate position thereof. The slit 33 at the intermediate position is V-shaped in plan view. The slit 33 at the center position is disposed on the side edge of the pixel electrode 46 and has a triangular shape in plan view. Further, the slits 33 on both ends have a linear shape substantially parallel to the slit 33 on the center side. The slits 33 are arranged at substantially equal intervals.

  The alignment state can be regulated so that the liquid crystal molecules are tilted with respect to the vertical direction shown in FIG. 3 (the direction orthogonal to the surface direction of both the substrates 11 and 12) by the step of the alignment film 30 in each slit 33. Due to the step formed by the slits 33, the rubbing process for the alignment film 30 can be made unnecessary. The depth of the slit 33 can be set to reach the insulating layer 32 as shown in FIG. 3, for example.

  Further, on the inner surface side of the CF substrate 11 (the liquid crystal layer 13 side and the surface facing the array substrate 12), color filters 36 are provided side by side at positions corresponding to the respective pixel electrodes 46, as shown in FIG. ing. The color filter 36 has a function of allowing transmission of light of a predetermined wavelength and absorbing light of other wavelengths. In the color filter 36 of the present embodiment, three color filters of R (red), G (green), and B (blue) are set. Each color filter 36 is arranged in the order of R, G, and B, for example.

  A light shielding layer 37 (black matrix) that shields light from the adjacent color filter 36 side is provided between the adjacent color filters 36 to prevent color mixing. The light shielding layer 37 is formed in a lattice shape so as to surround each color filter 36.

  Further, on the inner surface of the color filter 36, similarly to the pixel electrode 46, a counter electrode 48 made of, for example, ITO is formed. On the inner surface side of the counter electrode 48 of the present embodiment, ribs 34 (projections, protrusions, stepped portions) are provided. In the configuration of the present embodiment, the rib 34 protrudes from the inner surface of the counter electrode 48 toward the facing array substrate 12 and is formed in an elongated shape having a predetermined width. As shown in FIG. 2, the ribs 34 are formed in a V shape in plan view, and are arranged side by side at substantially the middle positions of the slits 33 adjacent to each other on the array substrate 12 side. Each rib 34 is formed such that its axial direction is substantially parallel to the extending direction of each slit 33.

  On the inner surface side of the counter electrode 48 and the rib 34, an alignment film 30 (30B) for aligning liquid crystal molecules in the liquid crystal layer 13 is formed. In other words, the alignment film 30 (30B) is formed on the surface of the counter electrode 48 and the rib 34 that is in contact with the liquid crystal layer 13. Therefore, a step is formed on the surface of the alignment film 30 (30B) by the ribs 34 protruding from the counter electrode 48. The alignment state can be regulated by this step so that the liquid crystal molecules are inclined with respect to the vertical direction shown in FIG. 3 (the direction perpendicular to the surface direction of both the substrates 11 and 12). By this step, the rubbing process for the alignment film 30 can be made unnecessary.

  In the liquid crystal panel 10, a defect site 50 may be generated in the alignment film 30 (30A, 30B) during the manufacturing process. A repair layer 35 made of a repair ink is formed on the defect portion 50 of this embodiment, and the repair portion 35 repairs the defect portion 50 of the alignment film 30.

  FIG. 4 is a plan view showing the array substrate 12 when a relatively large defect portion 50 is generated in the manufacturing process. In the configuration of the present embodiment, the repair layer 35 is formed in the defect portion 50, thereby completing the repair of the alignment film 30.

  The repair layer 35 is formed as shown in FIGS. FIGS. 5A to 5C are process cross-sectional views for explaining the process of forming the repair layer 35.

  First, after the step of forming the alignment film 30 is finished, as shown in FIG. 5A, a defect site 50 is found in the alignment film 30 by inspection.

  Next, as shown in FIG. 5B, a region (repair region) 55 including the defect site 50 discovered by the inspection is defined, and then the repair stamp in which the repair ink 61 is applied to the repair region 55. (Repair stamp) 60 is brought closer. Specifically, the repair stamp 60 with the repair ink 61 attached to the lower surface is held by the jig 62, and the repair stamp 60 is moved to the repair area 55. Next, the repair ink 61 of the repair stamp 60 is brought into contact with the defect site 50 (arrow 65), and then the repair stamp 60 is moved (arrow 52) to apply the repair ink 61 to the defect site 50. When the application of the repair ink 61 is completed, the repair stamp 60 is moved from the repair area 55 (arrow 66).

  Thereafter, as shown in FIG. 5C, the repair ink 61 applied to the repair region 55 is dried (see arrow 64) to form the repair layer 35. For example, when the repair ink 61 is an ultraviolet curable resin, the repair layer 35 is cured by irradiating with ultraviolet rays. In this way, the repair of the defect site 50 in the alignment film 30 is completed. Here, the defect site 50 of the alignment film 30 (30A) on the insulating layer 32 in the array substrate 12 is illustrated, but the same is performed for the alignment film 30 (30B) in the CF substrate 11.

  FIG. 6A is a diagram showing a state of the substrate (CF substrate) after the repair with the repair ink examined by the inventors of the present application. FIG. 6B is an enlarged view of the repair region 57.

  As shown in FIGS. 6A and 6B, the repair layer 35 is formed on the defect site 50 using the repair ink 61, whereby the defect site 50 is repaired. However, it was found that a peripheral edge (projection) 35b that was raised from the central portion 35a was formed around the central portion 35a of the repair layer 35.

  This peripheral portion (projection portion) 35b is a solid component (for example, polyimide component) of the material constituting the alignment film 30, and the peripheral portion 35b causes a ring-shaped spot (white spot) in the repair region 57. This stain causes a decrease in the contrast ratio of the liquid crystal panel. The stain due to the peripheral edge 35b may appear as a black stain depending on the state of light transmission. On the other hand, even if the same repair ink 61 is used, such a peripheral edge 35b (annular stain) may not occur, and it is very difficult to specify the cause of the occurrence of the stain.

  The inventor of the present application paid attention to the contact angle of the repair ink 61 during the examination of various angles. It is known that when a solution having a large contact angle is dried, a ring spot is generated. The ring stain is a phenomenon in which the solid content in the solution remains in a contour shape, for example, like a coffee stain on a table. Then, the inventor of the present application inferred that the protrusions 35 b are formed on the periphery of the repair layer 35 due to the contact angle height of the repair ink 61. Hereinafter, the mechanism by which the protruding portion (peripheral portion 35b) is generated will be described with reference to FIGS.

  First, as shown in FIG. 7A, the repair ink 61 is applied to the repair region 55 including the defect site 50 with the repair stamp 60. Next, due to the surface tension of the repairing ink 61, the repairing ink 61 becomes a convex substantially hemispherical shape having a predetermined contact angle θ1, as shown in FIG. 7B. Thereafter, as the solvent of the repair ink 61 evaporates, a repair layer 35 is formed which includes a protrusion (peripheral part) 35b located at the periphery and a flat support part (center part) 35a located at the center. That is, a ring spot is generated in the portion that is the outline of the repair ink 61, and this becomes a protrusion (peripheral portion) 35b. And this projection part (peripheral part) 35b may become causes, such as a fall of contrast ratio.

  Furthermore, the present inventor has noticed that certain polyimide materials (for example, photo-alignment polyimide materials) have a low imidization rate and are easily soluble in a solvent. When the repair ink 61 having a high content of a strong solvent (for example, a highly soluble solvent such as N-merylpyrrolidone (NMP)) is applied on the alignment film 30 made of the specific polyimide material, A portion of the alignment film is dissolved. In addition, since a strong solvent is required in order to dissolve a polyimide material, it is difficult to remove the strong solvent from the repair ink 61. And if the polyimide material which comprises the alignment film 30 melt | dissolves in the repairing ink 61, the projection part (peripheral part) 35b produced when the solvent of the repairing ink 61 evaporates may also become large.

  During such studies, the inventor of the present application diligently studied a method for suppressing the generation of the protruding portion (peripheral portion) 35b in the repair layer 35, and as a result, the following method was reached. Hereinafter, the method will be described in detail.

  In the configuration of this embodiment, when the alignment film 30 is formed, the alignment film 30 is formed on the surface of the substrate by discharging a coating liquid by an ink jet method. Here, the coating liquid has a solid content (for example, a solid content composed of polyimide) made of the material constituting the alignment film 30, a strong solvent (for example, NMP) that dissolves the solid content, and a solid content that is stronger than the strong solvent. And a weak solvent with poor solubility. The weak solvent is a solvent (adjustment solvent) that adjusts ink characteristics (for example, viscosity), and examples thereof include carbitol acetate and propylene carbonate. Moreover, a coating liquid (for inkjet) is solid content concentration 3-4% (mass%), for example, and a solvent component ratio is strong solvent: weak solvent = 50: 50 (volume ratio).

  In the configuration of the present embodiment, the repair ink 61 has a solid content concentration lower than the solid content concentration contained in the coating liquid. Further, the repair ink 61 of the present embodiment includes a solid content made of a material constituting the alignment film 30 (that is, the repair layer 35 in this case), a strong solvent (for example, NMP) that dissolves the solid content, and a strong solvent. Also includes a weak solvent (eg, carbitol acetate, propylene carbonate, etc.) that is poorly soluble in the solid content, and a low surface tension agent (eg, carbitol acetate, propylene carbonate, etc.) that lowers the contact angle of the repair ink 61. It is out. In addition, although the low surface tension agent of this embodiment is a liquid, it is also possible to use a solid thing. In the repair ink 61 of the present embodiment, the contact angle of the repair ink 61 can be reduced by including a low surface tension agent, and as a result, a protrusion (when the solvent of the repair ink 61 evaporates ( Generation | occurrence | production of (peripheral part) 35b can be suppressed or relieve | moderated.

  Next, the alignment film repairing process of this embodiment will be described with reference to FIGS.

  First, as shown in FIG. 7A, as shown in FIG. 8A, a repair ink 61 containing a low surface tension agent with a repair stamp 60 in a repair region 55 including a defect site 50). Is granted. Next, since the surface tension is reduced in the repair ink 61 of the present embodiment, as shown in FIG. 8B, the repair ink 61 has a contact angle θ1 (for example, 10%) shown in FIG. It becomes a flat shape having a contact angle θ2 (several degrees) smaller than several degrees to about 20 degrees.

  Thereafter, as shown in FIG. 8C, even if the solvent of the repair ink 61 is evaporated, the contact angle θ <b> 2 of the repair ink 61 is small. Can be suppressed or reduced. As a result, generation | occurrence | production of the projection part (peripheral part) 35b can be suppressed or eased.

  The solid content concentration of the repair ink 61 of this embodiment is 1/10 or less of the solid content concentration of the coating liquid. Specifically, the repair ink 61 has, for example, a solid content concentration of 0.1 to 0.2% (mass%) when the solid content concentration of the coating liquid is 3 to 4%. In the configuration of the present embodiment, the solvent ratio (volume%) of the strong solvent in the repair ink 61 is lower than the solvent ratio (volume%) of the strong solvent in the coating liquid. Specifically, when the low surface tension agent is a liquid, the ratio of the strong solvent, the weak solvent, and the low surface tension agent in the correction ink 61 (strong solvent: weak solvent: low surface tension agent) is 30:50: 20 (volume ratio). For more specific concentrations and ratios, those that are suitable in a timely manner according to the manufacturing process conditions (materials, equipment conditions, etc.) to be used may be adopted. Depending on the conditions, it is possible to use the same low surface tension agent and weak solvent.

  In addition, it is preferable from the viewpoint of management of the manufacturing process that the repair ink 61 is typically the same component as the coating liquid (for inkjet) or a diluted one thereof. In particular, if the defect site 50 of the alignment film 30 is to be repaired, the solid content concentration of the repair ink 61 is not required to be the same as the solid concentration (for example, 3 to 4%) of the coating liquid, and is lower than that. Things are enough. In the configuration of the present embodiment, the solvent ratio (volume%) of the strong solvent in the repair ink 61 is made lower than the solvent ratio (volume%) of the strong solvent in the coating liquid, that is, the ratio of the strong solvent is set. By reducing the amount, the amount of the alignment film 30 dissolved by the repair ink 61 can be reduced. In the example described above, the solvent ratio of the strong solvent in the coating liquid is 50% by volume (= 50 / (50 + 50)), and the solvent ratio of the strong solvent in the repair ink 61 is 30% by volume (= 30 / (30 + 50 + 20). ). Also by the effect of reducing the ratio of the strong solvent, it is possible to suppress the generation of the protrusion (peripheral part) 35b located at the peripheral edge. In particular, when the alignment film 30 made of a specific material (for example, a photo-alignment material) is used, the suppression effect can be greatly obtained.

  According to the configuration of the present embodiment, after forming the alignment film 30 on the surface of the substrate by discharging the coating liquid by an ink jet method, the repairing ink 61 is applied to repair the defective portion 50 of the alignment film 30. The coating liquid (for inkjet) includes a solid content made of a material constituting the alignment film 30, a strong solvent that dissolves the solid content, and a weak solvent. The repair ink 61 has a solid content concentration lower than the solid content concentration of the coating liquid. In addition, the repair ink 61 contains a low surface tension agent that reduces the contact angle. Therefore, the contact angle of the repair ink 61 can be reduced compared with the case where no low surface tension agent is contained. Therefore, a protrusion (periphery portion) is formed at a position located at the periphery of the repair ink 61. ) Can be suppressed. As a result, it becomes possible to repair defects in the alignment film more easily.

  Next, a manufacturing method of the liquid crystal panel according to the present embodiment, in particular, a method for repairing the alignment film will be described with reference to FIGS. 9 to 11 are diagrams showing the configuration of an ink jet type coating apparatus 200 used in the manufacturing method of the present embodiment. FIG. 12 is a diagram illustrating a configuration of the alignment film repairing apparatus 300 according to the present embodiment.

  The coating apparatus 200 shown in FIG. 9 is an apparatus (inkjet film forming apparatus) that applies a coating liquid to the substrate 70 by an inkjet method. The coating apparatus 200 of this embodiment includes a head unit 72 including a nozzle (not shown) that discharges a coating solution (solution) to the substrate 70 and a stage 74 that holds the substrate 70. In the configuration of the present embodiment, a plurality of inkjet heads are housed and arranged in the head cover 72 in the head cover. In addition, a plurality of nozzles are formed in one inkjet head. In addition, a surface (discharge surface) from which the solution is discharged from the nozzle is disposed to face the surface of the substrate 70. In the present embodiment, the alignment film (30) is formed on the surface of the substrate 70 by discharging the coating liquid from the head portion 72.

  The coating apparatus 200 according to the present embodiment is provided with a moving device 76 that relatively moves the head portion 72 and the stage 74 (see arrows 71a and 71b). In the configuration of the present embodiment, the head unit 72 is fixed and the stage 74 is movable. However, the stage 74 can be fixed and the head unit 72 can be movable. . However, since a pipe (not shown) for supplying an inkjet coating solution is connected to the head portion 72, there is a technical advantage in that the head portion 72 has a fixed configuration. In addition, the substrate 70 before coating is placed on the stage 74 from a transport device (not shown) that transports the substrate 70 from the previous process, and the substrate 70 after coating is moved to the subsequent process. Thus, there is also a technical advantage in keeping the stage 74 in a movable configuration.

  A control device 78 that controls the movement of the moving device 76 is connected to the moving device 76 of the present embodiment. The control device 78 is, for example, a personal computer (PC), for example, a storage device (for example, a hard disk, a semiconductor memory, an optical disk, etc.) in which a program (stage control program) that can control the movement of the moving device 76 is stored, a center An arithmetic circuit (CPU) and input / output devices (display, keyboard, mouse, etc.) are included. In the configuration of this embodiment, the stage 74 holding the substrate 70 can be moved in the XY direction under the control of the control device 78. Further, the control device 78 of this embodiment can also control the discharge of the solution from the head unit 72. In addition, the height of the head unit 72 (control in the Z direction) can also be performed.

  The board | substrate 70 of this embodiment is a glass substrate, for example, and the board | substrate 70 in this embodiment is a glass substrate for liquid crystal panels. In the illustrated example, the substrate 70 is a mother glass before being cut out to the dimensions of the liquid crystal panel. The size of the mother glass as the substrate 70 is 1 meter or more on one side. Specifically, when the substrate 70 is a 10th generation mother glass, the size is 2880 mm (W) × 3130 mm (L). The substrate 70 is not limited to the mother glass before being cut out to the dimensions of the liquid crystal panel, but may be glass having the size of the liquid crystal panel after being cut out. Further, the substrate 70 may be an array substrate on which a thin film transistor (TFT) is manufactured (or a product in the middle of manufacturing), or a CF substrate on which a color filter (CF) is formed (or a device in the middle of manufacturing thereof). It may be. The substrate 70 may be a resin substrate in addition to a glass substrate.

  The head unit 72 of this embodiment has a length that crosses the substrate 70 placed on the stage 74. In this example, the longitudinal direction of the head portion 72 extends in the Y direction. When the substrate 70 of the present embodiment is a 10th generation mother glass, the longitudinal length of the head portion 72 (length extending in the Y direction) is about 3 meters or more.

  The coating apparatus 200 of the present embodiment forms the alignment film (30) by moving over the substrate 70 while discharging a coating liquid from a nozzle (not shown) of the head unit 72. The coating solution here is, for example, a polyimide solution or a solution containing polyamic acid or a derivative thereof. As described above, the coating liquid contains a solid content made of a material constituting the alignment film, a strong solvent (for example, NMP) that dissolves the solid content, and an adjustment solvent.

  In the configuration shown in FIG. 9, the substrate 70 is moved along the direction in which the long side (L) or the short side (W) of the rectangular substrate 70 extends. However, as shown in FIG. It is also possible to move the substrate 70 with the substrate 70 inclined (arrows 71a and 71b). By moving the substrate 70 obliquely, depending on the pattern of the substrate 70 (for example, the array substrate), the solution (coating liquid) from the head portion 72 exhibits a predetermined wet spread, so that a specific part of the substrate 70 is obtained. This is because there is a case where it is possible to alleviate the phenomenon that it is difficult to wet.

  FIG. 11 shows an example of the configuration of the coating apparatus 200 of the present embodiment. In FIG. 11, an ink jet head 73 and a nozzle 73a located on the bottom surface of the head portion 72 are shown. In the example shown in FIG. 11, the inkjet heads 73 are not arranged in a line but are arranged so as to be diagonally arranged, but not limited thereto, other arrangements may be adopted. .

  For example, several tens of inkjet heads 73 are accommodated in the head portion 72. Each ink jet head 73 is formed with a plurality of nozzles 73a from which the coating liquid is discharged. For example, several hundreds of nozzles 73 a are formed in one inkjet head 73. In addition, although the arrangement | sequence of the nozzle 73a shown in FIG. 11 is staggered, you may arrange the nozzle 73a in a line. Alternatively, the arrangement of the nozzles 73a is not limited to a two-stage zigzag shape, but may be another arrangement (for example, a three-stage diagonal arrangement).

  The ink jet head 73 of the head unit 72 is connected to a coating liquid supply unit (for example, polyimide supply tank) 80 and a waste liquid unit (for example, waste liquid tank) 82. Specifically, each inkjet head 73 is connected to a supply pipe 85 via a branch pipe 87 and to a waste liquid pipe 86 via a branch pipe 89. The supply pipe 85 is connected to the coating liquid supply part 80, while the waste liquid pipe 86 is connected to the waste liquid part 82.

  Then, the coating liquid in the coating liquid supply unit 80 advances through the supply pipe 85 as indicated by an arrow 81, and is supplied to the inkjet head 73 through the branch pipe 87. Then, the waste liquid in the ink jet head 73 passes through the branch pipe 89, travels through the waste liquid pipe 86 as indicated by an arrow 83, and moves to the waste liquid section 82. Here, by adjusting the valve 88 (88a, 88b), it is possible to perform a process of making the pressure of the solution in the pipe 85 and the inkjet head 73 constant. Such processing may be executed based on the control of the control device 78 shown in FIG.

  Although the alignment film 30 can be formed on the surface of the substrate 70 by the coating apparatus 200 described above, a defect site (50) may be generated in the alignment film 30 in some cases. For example, if one of the large number of nozzles 73a does not discharge the coating liquid, that part may become a defective part (50). An example of an apparatus for repairing the defect site (50) is shown in FIG.

  FIG. 12 schematically shows the configuration of the repair device 300 of the present embodiment. The repair device 300 of the present embodiment is a device that repairs the defect site 50 of the alignment film 30. The repair device 300 can execute a repair process using the repair ink 61 described above. FIG. 13 is a block diagram illustrating a configuration of the repair device 300.

  The illustrated repair device 300 includes a repair stamp 60 to which the repair ink 61 of this embodiment is applied, a moving device 120 that moves the repair stamp 60, and a control device 110 that controls the moving device 120. In FIG. 12, the moving device 120 and the control device 110 are omitted.

  In the configuration example shown in FIG. 12, a stage 90 for holding a substrate (for example, an array substrate or a CF substrate) 70 having a repair region 55 is provided together with a supply box 98 for supplying the repair ink 61 of the present embodiment. ing. A glass substrate on which the alignment film 30 is formed is disposed on the stage 90 as the substrate 70. As described above, the alignment film 30 of this embodiment is formed by the ink jet method. The substrate 70 may be mother glass before being cut out to the dimensions of the liquid crystal panel, or may be glass having the size of the liquid crystal panel after being cut out.

  The supply box 98 includes a cleaning unit 98 a that cleans the repair stamp 60 and an ink supply unit 98 b that supplies the repair ink 61. A waste liquid receiving part 98c is provided below the cleaning part 98a and the ink supply part 98b. The waste liquid receiver 98c is connected to the waste liquid recovery tank 99. As described above, the repair ink 61 has a solid content concentration lower than the solid content concentration of the coating liquid, and the repair ink 61 contains a low surface tension agent. The repair ink 61 of the present embodiment is a solution in which the solvent ratio of the strong solvent in the repair ink 61 (strong solvent / whole solvent) is lower than the solvent ratio of the strong solvent in the coating liquid (strong solvent / whole solvent). is there.

  The repair stamp 60 is connected to a stamp jig 62. The stamp jig 62 is connected to the moving device 120, and the stamp 60 moves through the moving device 120 under the control of the control device 110 to execute a predetermined coating operation. Furthermore, the stage 90 that holds the substrate 12 can also be controlled by the control device 110, and in addition, both the stage 90 and the stamp 60 can be moved together by the control device 110. Specifically, when the stamp 60 is moved, it is possible to fix the stamp 60 and perform an interlocking operation to move the stage 90 instead.

  As shown in FIG. 13, a storage device 112, an input device 114, and an output device 116 are connected to the control device 110 of the present embodiment. The control device 110 is composed of, for example, a CPU (Central Processing Unit). The storage device 112 is a hard disk, a semiconductor memory, an optical disk (CD, DVD, etc.), a magneto-optical disk (MO), or the like. The input device 114 is, for example, a keyboard, a mouse, a touch panel, etc., and the output device 116 is a display device (liquid crystal display, CRT, organic EL display, etc.) or a printing device (laser printer, etc.). The control device 110, the storage device 112, the input device 114, and the output device 116 can be constructed by a personal computer (PC).

  An alignment film repair program 113 is stored in the storage device 112 connected to the control device 110. The alignment film repair program 113 is a program that controls the operation of the repair device 300, and includes a program that controls the movement of the repair stamp 60. The alignment film repair program 113 according to this embodiment includes a process including a step of moving the repair stamp 60 to the ink supply unit 98 b that supplies the repair ink 61 and a step of placing the repair stamp 60 in the repair region 55. This is a program to be executed. More specifically, the alignment film repair program 113 of the present embodiment is a program for executing operations indicated by arrows 91 to 97 (described later) and an arrow 52 in FIG.

  The repair device 300 according to the present embodiment includes an inspection device 130 that inspects the defect site 50 of the alignment film 30. The inspection device 130 is connected to the control device 110, and data on the defect site 50 detected by the inspection device 130 is output to the control device 110 and the storage device 112. The inspection device 130 includes an image sensor (for example, a CCD or a CMOS image sensor). The inspection device 130 also includes software for detecting the defect site 50 from the image data obtained by the image sensor, but this software can also be stored in the storage device 112. Further, the process of defining the repair region 55 from the data of the defect site 50 can be performed by the control device 110 or can be performed by the inspection device 130. Note that the specific configuration of the inspection device 130 is not particularly limited as long as it has a function of detecting the defect site 50 of the alignment film 30, and a suitable one may be adopted as appropriate. it can.

  In addition, the connection of each element (control apparatus 110 etc.) which comprises the repair apparatus 300 of this embodiment is not restricted to an electrical connection, For example, a wireless connection, an optical connection, etc. are employable. In addition, the control device 110 and the storage device 112 can be integrated, and the input device 114 and the output device 116 can be integrated (for example, a touch panel display). Further, a part of the connection can be made via the Internet. For example, the connection between the control device 110 and the storage device 112 is made via the Internet. It is also possible to use a hard disk or the like in a server at a location remote from 110.

  When a repair operation is executed using the repair device 300 of the present embodiment, the following operation may be performed. As described above, the movement of the repair stamp 60 is executed by the moving device 120 controlled by the control device 110. In addition, the moving device 120 of the present embodiment can move the repair stamp 60 in any of the X direction, the Y direction, and the Z direction.

  As shown in FIG. 12, the repair stamp 60 is first cleaned by bringing the bottom surface of the repair stamp 60 into contact with the cleaning portion 98a (see arrow 91). The cleaning part 98a contains a cleaning solvent (for example, N-methylpyrrolidone). Thereafter, the cleaned repair stamp 60 is moved (see arrow 92), and then the bottom surface of the repair stamp 60 is brought into contact with the ink supply unit 98b (see arrow 93). Then, the repair ink 61 adheres to the repair stamp 60.

  Next, the repair stamp 60 with the repair ink 61 attached is moved and placed above the stage 90 (see arrow 94). The repair stamp 60 then moves to the repair region 55 of the substrate 12 (arrow 95) where a repair process is performed (arrow 52) to form the repair layer 35. An example of a more detailed restoration process is as described in FIGS. 8A to 8C.

  Thereafter, the repair stamp 60 that has run out of the repair ink 61 moves (see arrow 96) and returns to the ink supply unit 98b (see arrow 97) for the next repair process. When starting the next repairing process, the repairing ink 61 is replenished by the ink supply unit 98b (see arrow 93), and thereafter the same processing may be performed again.

  For example, in the example shown in FIG. 14, there are two repair regions 55 (55a, 55b) on the substrate 12. Therefore, the repair process is performed once in the repair area 55a, and then the repair process is performed once more in the repair area 55b.

  In the above-described embodiment, for example, in FIGS. 2 and 3, the structure in which the slit 33 and the rib 34 are formed is shown. However, in the technique according to the embodiment of the present invention, such a slit 33 and the rib 34 are formed. It is also applicable to structures that are not. In particular, in the case of a liquid crystal panel having an alignment film (photo-alignment film) using a photo-alignment method, excellent visual field characteristics can be achieved without providing slots or ribs. More specifically, as the alignment film 30 of the present embodiment, it is possible to use a photo-alignment film whose alignment direction is defined by light irradiation. That is, a method of defining the pretilt direction of the liquid crystal molecules using a photo-alignment method can be used. The photo-alignment method sets the pretilt angle by irradiating the photo-alignment film with polarized light. Unlike the rubbing method, the photo-alignment method is a non-contact process because a light irradiation step that defines the alignment direction by light irradiation is performed. Therefore, there is an advantage that static electricity is not generated.

  After the alignment film 30 is repaired, the non-defective array substrate 12 and the non-defective CF substrate 11 are opposed to each other, and the liquid crystal layer 13 is formed between the CF substrate 11 and the array substrate 12. The liquid crystal layer 13 can be formed using, for example, a dropping injection method. After the structure including the CF substrate 11 and the array substrate 12 sandwiching the liquid crystal layer 13 is formed, polarizing plates 17 and 18 are attached to the outside of the CF substrate 11 and the array substrate 12. In the case of a normally white type, the polarizing plates 17 and 18 are arranged so that their polarization axes are orthogonal to each other. Thus, the liquid crystal panel 10 of this embodiment is obtained.

  The technology according to the embodiment of the present invention is not limited to the liquid crystal panel in which the liquid crystal molecules constituting the liquid crystal layer 13 are vertically aligned, but can also be applied to the repair of the alignment film 30 of liquid crystal panels other than the vertical alignment type. . In addition, the configuration of the backlight 20 of the liquid crystal display device 100 is not limited to the direct type shown in FIG. 1, but may be another configuration (for example, an edge light method).

  As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the liquid crystal panel which can repair the defect | deletion site | part of alignment film more easily can be provided.

DESCRIPTION OF SYMBOLS 10 Liquid crystal panel 11 CF board | substrate 12 Array board | substrate 15 Sealing material 17,18 Polarizing plate 20 Backlight 22 Light source 24 Case 26 Optical sheet 28 Frame 29 Bezel 30 Alignment film 31 Insulating layer 32 Insulating layer 33 Slit 34 Rib 35 Repair layer 35a Center part (Platform)
35b Perimeter (projection)
36 color filter 37 light shielding layer 41 source wiring 42 gate wiring 44 switching element 46 pixel electrode 48 counter electrode 50 defective portion 55 repair region 57 repair region 57 repair stamp 61 repair ink 62 stamp jig 70 substrate 72 head unit 73 inkjet head 73a Nozzle 74 Stage 76 Moving device 78 Control device 80 Coating liquid supply part 82 Waste liquid part 85 Supply pipe 86 Waste liquid pipe 87 Branch pipe 88 Valve 89 Branch pipe 90 Stage 98 Supply box 98a Cleaning part 98b Ink supply part 98c Waste liquid receiving part 99 Waste liquid recovery Tank 100 Liquid crystal display device 110 Control device 112 Storage device 113 Alignment film repair program 114 Input device 116 Output device 120 Moving device 130 Inspection device 200 Coating device 300 Repair device

Claims (7)

A method of manufacturing a liquid crystal panel,
Forming an alignment film on the surface of the substrate by discharging a coating solution by an inkjet method; and
Repairing the defective portion of the alignment film by applying a repair ink, and
The coating solution in the step of forming the alignment film is:
A solid content made of a material constituting the alignment film;
A strong solvent that dissolves the solids;
A weak solvent that is less soluble in the solid content than the strong solvent, and
The repair ink has a solid content concentration (mass%) lower than the solid content concentration (mass%) contained in the coating liquid, and
The repair ink is
The solid content;
A strong solvent that dissolves the solids;
A weak solvent that is less soluble in the solids than the strong solvent;
A method for producing a liquid crystal panel, comprising: a low surface tension agent that reduces a contact angle of the repair ink.   The method for producing a liquid crystal panel according to claim 1, wherein a solid content concentration of the repair ink is 1/10 or less of a solid content concentration of the coating liquid.   The method for producing a liquid crystal panel according to claim 1, wherein the solvent ratio of the strong solvent in the repair ink is lower than the solvent ratio of the strong solvent in the coating liquid.   The manufacturing method of the liquid crystal panel of Claim 3 whose solvent ratio (strong solvent: weak solvent) of the strong solvent and the weak solvent in the said coating liquid is 50:50. The low surface tension agent is a liquid;
The method for producing a liquid crystal panel according to claim 3, wherein a ratio of the strong solvent, the weak solvent, and the low surface tension agent (strong solvent: weak solvent: low surface tension agent) in the correction ink is 30:50:20. .   The method for manufacturing a liquid crystal panel according to claim 1, wherein the material constituting the alignment film is a photo-alignment material. The liquid crystal panel manufacturing method according to claim 6, wherein the photo-alignment material is a photo-alignment polyimide material.

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