JP2013167902A - Manufacturing method of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reduction of reliability of a seal portion resulting from degradation of an overcoat film in a portion having no alignment layer by ultraviolet radiation in optical alignment treatment in an IPS type liquid crystal display device.SOLUTION: In an IPS type liquid crystal display device, a light shielding film 202, a red color filter 201R, an overcoat film 203, and an alignment film 113 are formed in this order on a counter substrate 200. However, the alignment film 113 is not formed in a seal portion. When the alignment film 113 is subjected to photo-alignment with ultraviolet radiation, a portion of an overcoat film 2031 not covered with the alignment film 113 is degraded by the ultraviolet radiation. In order to prevent moisture penetrating from the degraded overcoat film 2031 from reaching the light shielding film 202 to alter the light shielding film 202 and from causing peeling of the light shielding film 202, the red color filter 201R is disposed below the overcoat film 203 to block the moisture.

Description

  The present invention relates to a display device, and more particularly to an IPS liquid crystal display device in which the reliability of a seal portion is improved.

  In a liquid crystal display device, there are a TFT substrate in which pixel electrodes and thin film transistors (TFTs) are formed in a matrix, and a counter substrate in which color filters are formed at locations corresponding to the pixel electrodes of the TFT substrate, facing the TFT substrate. The liquid crystal is sandwiched between the TFT substrate and the counter substrate. An image is formed by controlling the light transmittance of the liquid crystal molecules for each pixel.

  Since the liquid crystal display device is flat and lightweight, its application is expanding in various fields from a large display device such as a TV to a small display device such as a mobile phone and a DSC (Digital Still Camera). On the other hand, viewing angle characteristics are a problem in liquid crystal display devices. The viewing angle characteristic is a phenomenon in which luminance changes or chromaticity changes when the screen is viewed from the front and when viewed from an oblique direction. The viewing angle characteristic is excellent in an IPS (In Plane Switching) system in which liquid crystal molecules are operated by a horizontal electric field.

  In the IPS system, it is not necessary to form a pretilt angle for the liquid crystal molecules in the vicinity of the alignment film. For this reason, the alignment axis can be formed on the alignment film by the photo-alignment method, not by the rubbing method. The photo-alignment has advantages such as no generation of static electricity compared to the rubbing method.

  In the photo-alignment, the alignment film is irradiated with polarized ultraviolet rays so that the alignment film has anisotropy to align liquid crystal molecules in a predetermined direction. “Patent Document 1” is mentioned as a technique describing such a technique relating to photo-alignment.

JP-A-2005-351924

  Photo-alignment is performed by irradiating an alignment film formed of a polymer with ultraviolet rays polarized in a specific direction. For example, when a polymer formed in a network is irradiated with polarized ultraviolet rays, the polymer in a specific direction with respect to the polarization direction of the ultraviolet rays is destroyed. Thereby, anisotropy for aligning liquid crystal molecules in the alignment film can be formed. There is no problem if the polarized ultraviolet light to be photo-aligned is irradiated only to the alignment film, but if the portion other than the alignment film is irradiated, the irradiated portion deteriorates due to the ultraviolet light, causing a problem.

  IPS liquid crystal display devices are also used for small liquid crystal display devices. If small liquid crystal display devices are manufactured one by one, the efficiency is poor. Therefore, a large number of liquid crystal display devices are formed on a mother substrate, and a large number of liquid crystal display devices are manufactured simultaneously.

  FIG. 13 shows an example in which 35 small liquid crystal display cells 1 are formed on a mother substrate. A mother TFT substrate 1000 on which a large number of TFTs and TFT substrates 100 having pixel electrodes are formed is bonded to a mother counter substrate 2000 on which a large number of counter substrates 200 on which color filters and the like are formed. The mother TFT substrate 1000 and the mother counter substrate 2000 are bonded together with the sealing material 15 and the mother substrate sealing material 151. In FIG. 13, the hatched rectangle surrounded by the sealing material 15 indicates the range in which the alignment film 113 is formed.

  Small liquid crystal display devices are required to be thin. For example, the thicknesses of the TFT substrate and the counter substrate are as thin as about 0.2 mm. However, such a thin glass does not exist as a standard product. In addition, it is impossible to pass such a thin glass substrate through the process. Therefore, in the state of the mother counter substrate 2000 or the mother TFT substrate 1000, glass having a thickness of about 0.5 mm is used, and the mother counter substrate 2000 and the mother TFT substrate 1000 are bonded to form a mother substrate, and then the mother substrate is used. The outside of the counter substrate 2000 or the mother TFT substrate 1000 is polished.

Polishing is often performed using both mechanical polishing and chemical polishing. Whether the polishing is mechanical polishing or chemical polishing, if the abrasive enters the inside of the mother substrate, the liquid crystal cell 1 inside becomes defective. Therefore, the mother substrate sealing material 151 protects the inside of the mother substrate. The mother board sealing material 151 formed around the mother board is sealed with the mother board sealing material 161. The mother substrate shown in FIG. 13 is separated into liquid crystal cells after polishing.
FIG. 14 shows a state of the mother counter substrate 2000 constituting the mother substrate shown in FIG. 13, and 35 counter substrates 200 are formed corresponding to the liquid crystal cell 1 of FIG. FIG. 14 shows a stage before the seal material 15 or the mother substrate seal material 151 is formed on the mother counter substrate 2000. In FIG. 14, an alignment film 113 is formed for each counter substrate 200. When the alignment film is present in the seal portion, the adhesive force of the sealing material 15 is reduced. Therefore, the alignment film 113 is formed so as to avoid the seal portion and cover the display area.

  In FIG. 14, the alignment film 113 is formed by flexographic printing. After the alignment film 113 is formed, the alignment film 113 is optically aligned using polarized ultraviolet rays. At this time, irradiation of polarized ultraviolet rays is performed on the entire surface of the mother counter substrate 2000. This is because the manufacturing cost increases when polarized ultraviolet rays are irradiated to each alignment film. Therefore, the polarized ultraviolet rays are also irradiated to the portion where the alignment film is not formed.

  FIG. 15 is a cross-sectional structure at the end portion of each counter substrate 200 and shows a state in which polarized ultraviolet rays for photo-alignment are irradiated. As will be described later, a light shielding film 202, a color filter 201, an overcoat film 203, and the like are formed on the end portion of the counter substrate 200. The light shielding film 202 has a role of improving the contrast of the screen and improving the appearance of the periphery of the screen, and is also referred to as a black matrix, but in this specification, the term “light shielding film” is used. As shown in FIG. 15, in the portion where the alignment film 113 does not exist, the portion 2031 indicated by the oblique lines of the overcoat film 203 is directly irradiated with ultraviolet rays, so that the overcoat film 2031 in this portion is deteriorated and overcoated. The coating film 203 can easily pass moisture.

  FIG. 16 is an end cross-sectional view of the counter substrate 200 showing a state in which the sealing material 15 is formed after performing photo-alignment with polarized ultraviolet rays. Since a portion 2031 indicated by hatching in the overcoat film 203 is deteriorated by ultraviolet rays, moisture permeates the surface of the light shielding film 202 through the overcoat film 2031 of this portion.

  FIG. 17 is a cross-sectional view of the end portion of the liquid crystal display panel in a state where the TFT substrate 100 and the counter substrate 200 are bonded and the liquid crystal 300 is sealed inside. In FIG. 17, an inorganic passivation film 106, an organic passivation film 107, and an alignment film 113 are formed on the TFT substrate 100. In addition, a light shielding film 202, a color filter 201, an overcoat film 203, and an alignment film 113 are formed on the counter substrate 200. In FIG. 17, a portion 2031 indicated by hatching in the overcoat film 203 on the counter substrate 200 is deteriorated by ultraviolet rays at the time of photo-alignment, so that moisture easily enters from this portion into this portion.

  When moisture enters from the deteriorated overcoat film 2031, the moisture reaches the light shielding film 202 and alters the light shielding film 202. In particular, when moisture acts on the light shielding film 202, the adhesive force between the light shielding film 202 and the substrate 200 decreases, and the reliability of the seal portion decreases. Further, when moisture acts on the light shielding film 202, the electric resistance of the light shielding film 202 is reduced, the electric field in the liquid crystal layer 300 is disturbed by the influence of the light shielding film 202, and the contrast is lowered by light leakage.

  An object of the present invention is to prevent moisture entering from the outside due to an overcoat film deteriorated by ultraviolet irradiation during photo-alignment from affecting the light shielding film.

  The present invention solves the above-described problems, and a specific configuration is as follows.

  (1) A TFT substrate having a display area in which pixels having TFTs and pixel electrodes are formed in a matrix, a light shielding film and three color filters are formed, and an overcoat film is formed to cover the three color filters A liquid crystal display in which a counter substrate having a display region in which an alignment film is formed so as to cover the overcoat film is bonded by a sealing material at a peripheral seal portion, and liquid crystal is sealed between the TFT substrate and the counter substrate In the counter substrate, the alignment film is subjected to an alignment process by photo-alignment, and the alignment film is not formed on the seal portion. A light shielding film, one color filter of the three color filters, and an overcoat film are laminated in this order on the seal portion of the counter substrate, and the seal material is formed on the overcoat film. A liquid crystal display device, wherein:

  (2) A TFT substrate having a display area in which pixels having TFTs and pixel electrodes are formed in a matrix, a light shielding film and three color filters are formed, and an overcoat film is formed to cover the three color filters A liquid crystal display in which a counter substrate having a display region in which an alignment film is formed so as to cover the overcoat film is bonded by a sealing material at a peripheral seal portion, and liquid crystal is sealed between the TFT substrate and the counter substrate In the counter substrate, the alignment film is subjected to an alignment process by photo-alignment, and the alignment film is not formed on the seal portion. The seal portion of the counter substrate is formed by laminating a light shielding film and a plurality of color filters of the three color filters, and an overcoat film is formed covering the laminated color filters. A liquid crystal display device, wherein the sealing material is formed on the overcoat film.

  (3) One of the plurality of color filters formed on the seal portion is formed continuously with the color filter formed on the display area, and the other color filter of the plurality of color filters is the display. The liquid crystal display device according to (2), wherein the color filter formed in the region is not continuous.

  (4) A TFT substrate having a display area in which pixels having TFTs and pixel electrodes are formed in a matrix, a light shielding film and three color filters are formed, and an overcoat film is formed covering the three color filters. A liquid crystal display in which a counter substrate having a display region in which an alignment film is formed so as to cover the overcoat film is bonded by a sealing material at a peripheral seal portion, and liquid crystal is sealed between the TFT substrate and the counter substrate In the counter substrate, the alignment film is subjected to an alignment process by photo-alignment, and the alignment film is not formed on the seal portion. On the seal portion of the counter substrate, a light-shielding film, one color filter of the three color filters, and an overcoat film are laminated in this order, and the one color of the one color formed on the seal portion is formed. The color filter is not formed continuously with any of the three color filters formed in the display area, and corresponds to the end of the one color filter formed on the seal portion. The liquid crystal display device is characterized in that a step is formed on the film, and the sealing material is formed on the overcoat film.

  (5) A TFT substrate having a display region in which pixels having TFTs and pixel electrodes are formed in a matrix, a light shielding film and three color filters are formed, and an overcoat film is formed to cover the three color filters A liquid crystal display in which a counter substrate having a display region in which an alignment film is formed so as to cover the overcoat film is bonded by a sealing material at a peripheral seal portion, and liquid crystal is sealed between the TFT substrate and the counter substrate In the counter substrate, the alignment film is subjected to an alignment process by photo-alignment, and the alignment film is not formed on the seal portion. The seal portion of the counter substrate is formed by laminating a light shielding film and a plurality of color filters of the three color filters, and an overcoat film is formed covering the laminated color filters. The plurality of color filters formed in the seal portion are not continuously formed with any of the three color filters formed in the display area, and the plurality of color filters formed in the seal portion. A step is formed in the overcoat film corresponding to the end of the liquid crystal display device, and the sealing material is formed on the overcoat film.

  (6) A TFT substrate having a display area in which pixels having TFTs and pixel electrodes are formed in a matrix, a light shielding film and three color filters are formed, and an overcoat film is formed to cover the three color filters A liquid crystal display in which a counter substrate having a display region in which an alignment film is formed so as to cover the overcoat film is bonded by a sealing material at a peripheral seal portion, and liquid crystal is sealed between the TFT substrate and the counter substrate In the counter substrate, the alignment film is subjected to an alignment process by photo-alignment, and the alignment film is not formed on the seal portion. A light shielding film and an overcoat film are laminated in this order on the seal portion of the counter substrate, and the thickness of the overcoat film in the seal portion is larger than the film thickness of the overcoat film in the display region. A liquid crystal display device characterized in that the sealing material is formed on the overcoat film.

  (7) The liquid crystal display device according to (6), wherein a film thickness of the overcoat film in the seal portion is 1.5 times or more of a film thickness of the overcoat film in the display region.

  According to the present invention, in the photo-alignment, even if the overcoat film of the seal portion deteriorates due to the ultraviolet rays, even if the color filter is disposed under the overcoat film, the moisture can permeate the overcoat film. Since moisture is blocked by the color filter and hardly reaches the light shielding film, peeling of the light shielding film can be prevented. In addition, since it is possible to prevent the electric resistance of the light shielding film from being lowered, it is possible to prevent a reduction in contrast due to light leakage of the liquid crystal layer.

  According to another aspect of the present invention, since the overcoat film of the seal portion is formed thicker than the overcoat film of the display area, the entire overcoat film is prevented from being deteriorated by ultraviolet rays during photo-alignment. Therefore, it is possible to prevent moisture from reaching the light shielding film. In addition, since the thickness of the overcoat film in the display area is not increased, a reduction in the luminance of the display screen can be prevented.

It is a top view of a liquid crystal display device. It is sectional drawing of the display area of a liquid crystal display device. 3 is a cross-sectional view of a seal portion of the liquid crystal display device of Example 1. FIG. It is sectional drawing which shows the counter substrate at the time of photo-alignment. 2 is a cross-sectional view of a counter substrate of Example 1. FIG. 6 is a cross-sectional view of a counter substrate of Example 2. FIG. 6 is a cross-sectional view of a counter substrate according to another embodiment of Example 2. FIG. 6 is a cross-sectional view of a counter substrate of Example 3. FIG. 7 is a cross-sectional view of a counter substrate of Example 4. FIG. 6 is a cross-sectional view of a counter substrate according to another embodiment of Example 2. FIG. 10 is a cross-sectional view of a counter substrate of Example 5. FIG. 10 is a cross-sectional view of a counter substrate according to another embodiment of Example 5. FIG. It is a top view of a mother board. It is a top view of a mother counter substrate. It is sectional drawing which shows the counter substrate at the time of the photo-alignment in a prior art example. It is sectional drawing which shows the counter substrate in the state in which the sealing material in the prior art example was formed. It is sectional drawing of the edge part of the liquid crystal display device in a prior art example.

  Hereinafter, the contents of the present invention will be described in detail by way of examples.

  FIG. 1 is a plan view of a small liquid crystal display device used in a mobile phone or the like, which is an example of a product to which the present invention is applied. In FIG. 1, a counter substrate 200 is installed on the TFT substrate 100. A liquid crystal layer is sandwiched between the TFT substrate 100 and the counter substrate 200. The TFT substrate 100 and the counter substrate 200 are bonded together by a sealing material 15 formed on the frame portion. In FIG. 1, a sealing hole is formed in the sealing material 15, and liquid crystal is sealed from the sealing hole. Thereafter, the sealing hole is sealed with a sealing material 16.

  The TFT substrate 100 is formed larger than the counter substrate 200, and a terminal for supplying power, a video signal, a scanning signal, etc. to the liquid crystal display panel in a portion where the TFT substrate 100 is larger than the counter substrate 200. A portion 150 is formed. The terminal unit 150 is provided with an IC driver 50 for driving scanning lines, video signal lines, and the like. The IC driver 50 is divided into three regions, a video signal driving circuit 52 is installed at the center, and a scanning signal driving circuit 51 is installed on both sides.

  In the display area 10 of FIG. 1, scanning lines 30 extend in the horizontal direction and are arranged in the vertical direction. The video signal lines 40 extend in the vertical direction and are arranged in the horizontal direction. The scanning line 30 is connected to the scanning signal driving circuit 51 of the IC driver 50 by a scanning line lead line 31. In FIG. 1, in order to arrange the display area 10 in the center of the liquid crystal display device, the scanning line lead lines 31 are arranged on both sides of the display area 10. For this reason, the IC driver 50 includes a scanning signal driving circuit 51. It is installed on both sides. On the other hand, the video signal line lead line 41 connecting the video signal line 40 and the IC driver 50 is gathered on the lower side of the screen. The video signal line lead line 41 is connected to a video signal drive circuit 52 disposed at the center of the IC driver 50.

  An alignment film 113 is formed in a region slightly wider than the display region 10 in FIG. This alignment film 113 is photo-aligned. The alignment film 113 is not formed on the portion where the sealing material 15 is formed. This is because when the alignment film 113 is present, the adhesive force between the sealing material 113 and the substrate decreases.

  FIG. 2 is a cross-sectional view showing a structure in a display region of an IPS liquid crystal display device. Various electrode structures of IPS liquid crystal display devices have been proposed and put into practical use. The structure shown in FIG. 1 is a structure that is widely used at present. To put it simply, a comb-like pixel electrode 110 is formed on a counter electrode 108 formed of a flat solid with an interlayer insulating film 109 interposed therebetween. Has been. Then, an image is formed by controlling the light transmittance of the liquid crystal layer 300 for each pixel by rotating the liquid crystal molecules 301 by the voltage between the pixel electrode 110 and the counter electrode 108. The structure of FIG. 1 will be described in detail below. Although the present invention will be described by taking the configuration of FIG. 1 as an example, the present invention can also be applied to IPS type liquid crystal display devices other than FIG.

  In FIG. 2, a gate electrode 101 is formed on a TFT substrate 100 made of glass. The gate electrode 101 is formed in the same layer as the scanning line. The gate electrode 101 has a MoCr alloy laminated on an AlNd alloy.

  A gate insulating film 102 is formed of SiN so as to cover the gate electrode 101. A semiconductor layer 103 is formed of an a-Si film on the gate insulating film 102 at a position facing the gate electrode 101. The a-Si film is formed by plasma CVD. The a-Si film forms the channel portion of the TFT, and the source electrode 104 and the drain electrode 105 are formed on the a-Si film with the channel portion interposed therebetween. Note that an n + Si layer (not shown) is formed between the a-Si film and the source electrode 104 or the drain electrode 105. This is for making ohmic contact between the semiconductor layer and the source electrode 104 or the drain electrode 105.

  The source electrode 104 is also used as a video signal line, and the drain electrode 105 is connected to the pixel electrode 110. The source electrode 104 and the drain electrode 105 are simultaneously formed in the same layer. In this embodiment, the source electrode 104 or the drain electrode 105 is made of a MoCr alloy. When it is desired to lower the electrical resistance of the source electrode 104 or the drain electrode 105, for example, an electrode structure in which an AlNd alloy is sandwiched between MoCr alloys is used.

  An inorganic passivation film 106 is formed of SiN so as to cover the TFT. The inorganic passivation film 106 protects the TFT, particularly the channel portion, from the impurities 401. An organic passivation film 107 is formed on the inorganic passivation film 106. The organic passivation film 107 has a role of flattening the surface at the same time as protecting the TFT, and thus is formed thick. The thickness is 1 μm to 4 μm.

  A counter electrode 108 is formed on the organic passivation film 107. The counter electrode 108 is formed by sputtering ITO (Indium Tin Oxide), which is a transparent conductive film, over the entire display region. That is, the counter electrode 108 is formed in a planar shape. After the counter electrode 108 is formed on the entire surface by sputtering, the counter electrode 108 is removed by etching only in the through hole 111 portion for conducting the pixel electrode 110 and the drain electrode 105.

  An interlayer insulating film 109 is formed of SiN so as to cover the counter electrode 108. After the interlayer insulating film 109 is formed, a through hole 111 is formed. Thereafter, ITO that will be the pixel electrode 110 is deposited so as to cover the interlayer insulating film 109 and the through hole 111. The pixel electrode 110 is formed by patterning the deposited ITO. ITO serving as the pixel electrode 110 is also deposited on the through hole 111. In the through hole 111, the drain electrode 105 extending from the TFT and the pixel electrode 110 become conductive, and a video signal is supplied to the pixel electrode 110.

  The pixel electrode is a so-called comb-like electrode. A slit 112 shown in FIG. 2 is formed between the comb-shaped electrode and the comb-shaped electrode. A constant voltage is applied to the counter electrode 108, and a voltage based on a video signal is applied to the pixel electrode 110. When a voltage is applied to the pixel electrode 110, as shown in FIG. 1, the lines of electric force are generated, and the liquid crystal molecules 301 are rotated in the direction of the lines of electric force to control the transmission of light from the backlight. Since transmission from the backlight is controlled for each pixel, an image is formed. A TFT substrate-side alignment film 113 for aligning the liquid crystal molecules 301 is formed on the pixel electrode 110. For the alignment treatment on the alignment film, photo-alignment using polarized ultraviolet rays is used.

  In the example of FIG. 2, a counter electrode 108 formed in a planar shape is disposed on the organic passivation film 107, and a comb electrode 110 is disposed on the interlayer insulating film 109. However, on the contrary, the pixel electrode 110 formed in a planar shape may be disposed on the organic passivation film 107, and the comb-like counter electrode 108 may be disposed on the interlayer insulating film 109.

  In FIG. 2, the counter substrate 200 is installed with the liquid crystal layer 300 interposed therebetween. A color filter is formed inside the counter substrate 200. In FIG. 2, a red color filter 201R is formed. A light shielding film 202 is formed in a region below the color filter where an image is not formed. The light shielding film 202 improves the contrast of the image and has a role as a light shielding film of the TFT to prevent a photocurrent from flowing through the TFT.

  An overcoat film 203 is formed to cover the color filter 201 and the light shielding film 202. Since the surfaces of the color filter 201 and the light shielding film 202 are uneven, the surface is flattened by the overcoat film 203. On the overcoat film 203, an alignment film 113 for determining the initial alignment of the liquid crystal is formed. The alignment film 113 is subjected to photo-alignment processing.

  Since FIG. 2 shows IPS, the counter electrode 108 is formed on the TFT substrate 100 side, and is not formed on the counter substrate 200 side. Thus, in IPS, the conductive film is not formed inside the counter substrate 200. Then, the potential of the counter substrate 200 becomes unstable. Further, external electromagnetic noise enters the liquid crystal layer 300 and affects the image. In order to eliminate such a problem, a surface conductive film 210 is formed outside the counter substrate 200. The surface conductive film 210 is formed by sputtering ITO, which is a transparent conductive film.

  FIG. 3 is a cross-sectional view at the end of the liquid crystal display device shown in FIG. In FIG. 3, an inorganic passivation film 106, an organic passivation film 107, and an alignment film 113 are formed on the TFT substrate 100. The other configuration of the TFT substrate 100 is omitted in FIG. On the counter substrate 200, a light shielding film 202, a red color filter 201R, an overcoat film 203, and an alignment film 113 are formed. The ends are sealed with a sealing material 15, and the distance between the TFT substrate 100 and the counter substrate 200 is defined by a spacer 350 made of glass fiber.

  In FIG. 3, the alignment film 113 is subjected to an alignment process by photo-alignment. A feature of the present invention shown in FIG. 3 is that a red color filter 201R is disposed under the overcoat film 203 at the end. Although the red color filter 210R is formed in FIG. 3, it may be a green color filter or a blue color filter. In the counter substrate 200 of FIG. 3, the portion of the overcoat film 203 where the alignment film 113 is not present is deteriorated by ultraviolet rays during photo-alignment, and moisture is likely to enter.

  Even if the overcoat film 203 is deteriorated by ultraviolet rays, the red color filter 201R exists under the overcoat film 203. Therefore, the moisture that has entered the overcoat film 203 is blocked by the red color filter 201R and does not reach the lower light shielding film 202 or takes a long time to reach. Accordingly, it is possible to prevent a decrease in adhesive force due to the reaction of the light shielding film 202 with moisture or a decrease in electric resistance of the light shielding film 202.

  4 and 5 illustrate the above description. FIG. 4 shows a state in which the light shielding film 202, the red color filter 201R, the overcoat film 203, and the alignment film 113 are formed in this order on the counter substrate 200. The light shielding film 202 has a thickness of about 1 μm, the red color filter 201R has a thickness of 1 to 2 μm, the overcoat film 203 has a thickness of 1 to 2 μm, and the alignment film 113 has a thickness of about 0.1 μm. The film thickness of a green color filter, a blue color filter, etc. is also 1-2 micrometers.

  The alignment film 113 is not formed at the end. This is to prevent the adhesion force of the sealing material 15 from being lowered by the alignment film 113. In FIG. 4, ultraviolet rays UV are irradiated to the alignment film 113 for alignment treatment. The alignment film 113 is subjected to alignment treatment with ultraviolet rays, but the overcoat film 2031 that is shaded at the end portion where the alignment film 113 does not exist is deteriorated by ultraviolet rays.

  Thereafter, as shown in FIG. 5, the sealing material 15 is formed on the overcoat film 203 at the end portion where the alignment film 113 does not exist. In FIG. 5, moisture easily penetrates into a portion 2031 indicated by oblique lines of the overcoat film deteriorated by ultraviolet rays. However, since the red color filter 201R exists under the overcoat film 2031 indicated by the oblique lines, the intruded moisture is blocked by the red color filter 201R and does not easily reach the light shielding film 202. Therefore, the reliability of the seal portion can be ensured.

  Conventionally, the color filter is formed only in the display region, but in the present invention, this is extended to the end of the counter substrate 200. The color filter is formed by photolithography. That is, the formation range of the color filter can be defined by the exposure mask. Therefore, even if the color filter is formed up to the end portion of the counter substrate, the number of steps does not increase.

  As described above, according to the present embodiment, even if the overcoat film 203 is deteriorated by ultraviolet rays in the photo-alignment process, the color filter blocks the influence of moisture that has permeated the overcoat film 203. There will be no decrease in reliability. In addition, since a decrease in electrical resistance of the light shielding film 202 due to moisture reacting with the light shielding film 202 can be prevented, a decrease in contrast due to light leakage of liquid crystal can be prevented.

  In the above embodiment, the color filter formed in the seal portion is the red color filter 201R. However, this is an example, and other color filters, that is, the green color filter even if it is a blue color filter. It may be a filter.

  FIG. 6 is a cross-sectional view in the vicinity of the end of the counter substrate 200 according to the second embodiment of the present invention. In FIG. 6, a light shielding film 202, a red color filter 201R, an overcoat film 203, and an alignment film 113 are formed in this order on the counter substrate 200. However, the red color filter 201R and the green color filter 201G are laminated on the seal portion where the alignment film 113 does not exist. The alignment film 113 is subjected to photo-alignment processing. Therefore, the portion of the overcoat film 203 where the alignment film 113 is not present is deteriorated by ultraviolet rays.

  In FIG. 6, two layers of color filters, a green color filter 201G and a red color filter 201R, are formed under the overcoat film 203 deteriorated by ultraviolet rays. Therefore, even if moisture penetrates into the deteriorated overcoat film 203, the penetrated moisture is blocked by the green color filter 201G and the red color filter 201R and does not reach the light shielding film 202.

  6 has two layers of color filters in the seal portion, and therefore has a greater protective effect against moisture than the configuration of the first embodiment. The film thickness of each layer is the same as in Example 1. That is, both the green color filter and the red color filter are formed to a thickness of 1 to 2 μm as in the first embodiment.

  Another effect of the configuration of FIG. 6 is that the alignment film 113 can be prevented from entering the seal portion when the alignment film 113 is applied. As shown in FIG. 6, since the green color filter 201G is formed in the vicinity of the end portion, a step is generated in the overcoat film 203, and this step serves as a stopper for the alignment film 203 flowing from the display region. Have.

  Since the alignment film 203 is a liquid when applied, it has fluidity and it is difficult to accurately define the application area. In particular, when the alignment film 113 exists under the sealing material 15, the adhesive force of the sealing material 15 is reduced. In this embodiment, as shown in FIG. 6, since the range of the alignment film 113 can be defined by forming a step with the green phosphor 201G, the reliability in the seal portion can be kept high. In addition, since the green color filter 201G formed in the periphery is formed by photolithography, accurate dimensions can be maintained. The height of the step is about 1-2 μm, which is the thickness of the green color filter.

  FIG. 7 shows another aspect of this embodiment. The display area on the left side of FIG. 7 is the same as that described with reference to FIG. 6, but the end portion is different from FIG. 6, and the red color filter 201 </ b> R is sequentially placed between the light shielding film 202 and the overcoat film 203. Three layers of color filters, green color filter 201G and blue color filter 201B, are formed. The alignment film 113 is subjected to a photo-alignment process as in the first embodiment or FIG.

  In FIG. 7, the portion of the overcoat film 203 that is not covered with the alignment film 113 is deteriorated by ultraviolet rays during photo-alignment, as in the first embodiment. In this embodiment, since the three layers of color filters exist before the moisture that has permeated the deteriorated overcoat film 203 reaches the light shielding film 202, the reliability of the seal portion is further increased than in the case of FIG. Can be improved.

  Further, as shown in FIG. 7, a step is formed in the vicinity of the seal portion by the two color filters of the green color filter 201G and the blue color filter 201B, and the formation range of the alignment film 113 is defined by this step. I can do it. In this embodiment, the step is formed by two layers of color filters, and the size of the step can be formed to about 2 μm to 4 μm. Therefore, the coating range of the alignment film can be more reliably defined.

  In this embodiment, in FIG. 6, the red color filter 201R and the green color filter 201G are sequentially stacked. However, the two-layer color filter is not limited to this, and other color filters may be used, and the order of stacking may also be determined. It may be different. In FIG. 7, the order of the color filters to be stacked is the order of the red color filter 201R, the green color filter 201G, and the blue color filter 201B. However, the order of stacking the color filters is not limited to this, It can be arbitrarily determined according to the manufacturing conditions.

  FIG. 8 is a cross-sectional view of the vicinity of the end portion of the counter substrate 200 according to the third embodiment. In FIG. 8, a light shielding film 202, a red color filter 201R, an overcoat film 203, and an alignment film 113 are formed in this order on the counter substrate 200. The alignment film 113 is subjected to photo-alignment processing. Therefore, the portion of the overcoat film 203 that is not covered with the alignment film 113 is deteriorated by the ultraviolet rays during the photo-alignment.

  By disposing the red color filter 201R between the overcoat film 203 deteriorated by the ultraviolet rays and the light shielding film 202, it is possible to block the water that has penetrated into the deteriorated overcoat film 203 with the red phosphor 201R. Similar to Example 1. In this embodiment, unlike the first embodiment, the red color filter 201R is not continuously formed up to the end portion, but the red phosphor is removed between the display region and the seal portion, that is, FIG. A part in is provided.

  Even when only one red color filter layer is formed in the seal portion due to the presence of the A portion, a step with respect to the alignment film 113 can be formed, and this step can be used as a stopper against the spread of the alignment film. In addition, the A part acts as a liquid pool with respect to the alignment film 113, and can more reliably prevent the alignment film 113 from spreading outward along with the step.

  In the present embodiment, the color filter formed in the seal portion is the red color filter 210R. However, this is an example, and other color filters, that is, the green color filter 201G may be blue. The filter 201B may be used.

  FIG. 9 is a cross-sectional view of the vicinity of the end portion of the counter substrate 200 according to the fourth embodiment. In FIG. 9, a light shielding film 202, a red color filter 201R, an overcoat film 203, and an alignment film 113 are formed in this order on the counter substrate 200. However, the red color filter 201R and the green color filter 201G exist between the overcoat film 203 and the light shielding film 202 in the seal portion. The alignment film 113 is subjected to photo-alignment processing. Therefore, the portion of the overcoat film 203 that is not covered with the alignment film 113 is deteriorated by the ultraviolet rays during the photo-alignment.

  The arrangement of the red color filter 201R and the green color filter 201G between the overcoat film 203 deteriorated by ultraviolet rays and the light-shielding film blocks the water that has permeated the deteriorated overcoat film 203. This is the same as FIG. In this embodiment, unlike FIG. 6, the red color filter 201R is not continuously formed up to the end portion, but the red color filter 201R is removed between the display region and the seal portion, A in FIG. Provide a part.

  Due to the presence of the A portion, the step formed in the vicinity of the seal portion becomes two layers of the red color filter 201R and the green color filter 201G, and the size of the step can be set to 2 μm to 4 μm. Therefore, the alignment film 113 that attempts to spread outward can be more effectively regulated. In addition, the A part acts as a liquid pool with respect to the alignment film 113, and can more reliably prevent the alignment film 113 from spreading outward along with the step.

  FIG. 10 is a cross-sectional view of the vicinity of the end portion of the counter substrate 200 showing another aspect of the fourth embodiment. FIG. 10 is the same as FIG. 9 except that there are three color filters of red color filter 201R, green color filter 201G, and blue color filter 201B between the overcoat film 203 and the light shielding film 202 in the seal portion. It is the same.

  In the configuration of FIG. 10, the red overcoat film 203R, the green color filter 201G, and the blue color filter 201B are disposed between the overcoat film 203 and the light-shielding film 202 that are deteriorated due to ultraviolet rays at the time of photo-alignment. Blocking the moisture that has permeated 203 is the same as in FIG. However, in this embodiment, unlike FIG. 7, the red color filter 201R is not formed continuously to the end, but the red phosphor 201R is removed between the display region and the seal portion, FIG. A part in is provided.

  Due to the presence of the A portion, the step formed in the vicinity of the seal portion is equivalent to three layers of the red color filter 201R, the green color filter 201G, and the blue color filter 201B, and the alignment film 113 that attempts to spread outward is more effectively regulated. I can do it. Since it is a step for three layers, the step can be about 3 μm to 6 μm, and even when the viscosity of the alignment film 113 is small, it can sufficiently serve as a stopper. In addition, the A part acts as a liquid pool with respect to the alignment film 113, and can more reliably prevent the alignment film 113 from spreading outward along with the step.

  Thus, in the present embodiment, the influence of moisture that has permeated into the deteriorated overcoat film 203 can be prevented more reliably than in the case of the third embodiment. Also, the outer shape of the alignment film 113 can be defined more reliably according to the configuration of this embodiment.

  In the present embodiment, the red color filter 201R and the green color filter 201G are sequentially stacked in FIG. 9, but the two-layer color filter is not limited to this, and other color filters may be used, and the stacking order may also be different. It may be different. In FIG. 10, the order of the color filters to be stacked is the order of the red color filter, the green color filter, and the blue color filter, but the order of the color filter stacking is not limited to this, and depends on the manufacturing conditions of the color filter. It can be decided arbitrarily.

  FIG. 11 is a cross-sectional view of the vicinity of the end of the counter substrate 200 showing the fifth embodiment of the present invention. In FIG. 11, on the counter substrate 200, a light shielding film 202, a red color filter 201R, an overcoat film 203, and an alignment film 113 are formed in this order. However, in the seal portion, the light shielding film 202 and the overcoat film 203 are formed on the counter substrate 200, and the seal material 15 is formed thereon. In FIG. 11, the color filter is not formed on the seal portion.

  Also in this embodiment, the alignment film 113 is subjected to a photo-alignment process. Therefore, the portion of the overcoat film 203 where the alignment film 113 does not exist is deteriorated by ultraviolet rays during photo-alignment. The penetration of moisture from the deteriorated overcoat film is the same as in Examples 1 to 4.

  The feature of this embodiment is that the film thickness of the overcoat film 203 is larger than the film thickness in the display area in the seal portion. In FIG. 11, the film thickness of the overcoat film 203 in the seal portion is d2, and the film thickness of the display area is d1. As a ratio of the film thickness d1 in the display area of the overcoat film 203 to the film thickness d2 in the seal portion, d2 is preferably at least twice as large as d1, but the effect can be obtained even at 1.5 times or more. When d2 is twice d1, if the thickness d1 in the display region is 1 to 2 μm, d2 is 2 to 4 μm. In the display area, if the thickness of the overcoat film 203 is increased, the light transmittance is reduced and the brightness of the screen is lowered. Therefore, the thickness d1 of the overcoat film 203 in the display area is suppressed to 1 to 2 μm. It is necessary to keep.

  During the photo-alignment, the overcoat film 203 not covered with the alignment film 113 is deteriorated by ultraviolet rays. However, the region deteriorated by ultraviolet rays is mainly near the surface and is not greatly affected by ultraviolet rays in the deep part of the film. In this embodiment, the thick portion of the overcoat film 203 that is directly irradiated with ultraviolet rays is thickened so that the deep portion of the overcoat film 203 is not destroyed by the ultraviolet rays.

  Therefore, even if the surface of the overcoat film 203 is destroyed by ultraviolet rays and moisture penetrates, the deep part of the overcoat film 203 is not destroyed, so that the water is blocked in the deep part of the overcoat film 203, It does not reach the light shielding film 202. Accordingly, it is possible to prevent a phenomenon in which moisture reacts with the light shielding film 202 to cause peeling of the light shielding film 202 or an electrical resistance of the light shielding film 202 is reduced.

  A half exposure technique can be used as a method of forming the light shielding film 202 thick only at the periphery. For example, when a positive photosensitive material is used for the overcoat film 203, the exposed portion is dissolved in the developer, and therefore an exposure mask that reduces the exposure amount of the overcoat film at the seal portion is used. Thus, the thickness of the overcoat film can be increased only by the seal portion.

  Also in this embodiment, a step is formed between the thin portion and the thick portion of the overcoat film 203, and this step can be used as a stopper for the alignment film 113. In this case, the step to be formed is 1 μm to 2 μm. In addition, since the concave portion formed between the end portion of the red color filter 201R and the step portion of the overcoat film 203 can serve as a liquid reservoir for the alignment film 113, a step difference in the overcoat film 203 is obtained. In combination with this, it is possible to contribute to defining the outer shape of the alignment film 113.

  FIG. 12 is a modification of the present embodiment, and is an example in which the present embodiment is combined with the configuration of the first embodiment. That is, in the seal portion, the film thickness of the overcoat film 203 is made larger than that of the display area, and the red color filter 201R is disposed below the overcoat film 203. As a result, the action of protecting the light shielding film 202 from the influence of moisture penetrating the surface of the overcoat film 203 deteriorated by ultraviolet rays can be further ensured.

  FIG. 12 is an example in which the fifth embodiment is combined with the first embodiment, but the fifth embodiment can be combined with the second to fourth embodiments. When Example 5 is combined with Examples 2 to 4, the height of the step that acts as a stopper for the alignment film 113 can be increased, and an alignment film having a low viscosity can be used.

  Note that as a method of forming the alignment film 113, there is a method of forming by an inkjet method in addition to flexographic printing. When forming an alignment film by the inkjet method, it is necessary to reduce the viscosity of the alignment film. When the viscosity of the alignment film is small, the alignment film tends to spread around the periphery, and it becomes difficult to accurately define the formation range of the alignment film. In such a case, if the present invention described in Embodiment 2 and later is used, a step is formed in the overcoat film 203, so that the alignment film can be prevented from spreading outward. That is, by using the present invention, it is possible to apply an alignment film having a low viscosity, and the options for the formation process of the alignment film can be expanded.

  In the above-described embodiment, the color filter formed in the seal region is formed up to the end of the counter substrate. However, the color filter may be terminated stepwise before the end of the counter substrate. As a result, it is possible to prevent peeling of the color filter or the like at the edge of the substrate. Further, instead of forming the color filter over the entire seal area, it is possible to remove a part of the color filter in the seal area. The shape of the removed portion may be an island shape or a thin stripe shape parallel to the side of the substrate. Thereby, a region where the overcoat film and the light shielding film are in contact with each other is formed in a part of the seal region. Further, since the step portion of the color filter is present in the seal portion, the adhesion area of the seal material is increased, so that the adhesive strength between the seal material and the counter substrate can be increased, and the reliability of the seal portion is improved. .

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal cell, 10 ... Display area, 15 ... Sealing material, 16 ... Sealing material, 30 ... Scan line, 31 ... Scan line lead line, 40 ... Video signal line, 41 ... Video signal line lead line, 50 ... IC Driver 51: Scanning signal driving circuit 52 ... Video signal driving circuit 100 ... TFT substrate 101 ... Gate electrode 102 ... Gate insulating film 103 ... Semiconductor layer 104 ... Source electrode 105 ... Drain electrode 106 ... Inorganic Passivation film, 107 ... Organic passivation film, 108 ... Counter electrode, 109 ... Interlayer insulating film, 110 ... Pixel electrode, 111 ... Through hole, 112 ... Slit, 113 ... Alignment film, 150 ... Terminal part, 151 ... Mother substrate sealing material 161 ... Mother substrate sealing material, 200 ... Counter substrate, 201 ... Color filter, 201R ... Red Lar filter, 201G ... green color filter, 201B ... blue color filter, 202 ... light shielding film, 203 ... overcoat film, 210 ... external conductive film, 300 ... liquid crystal layer, 301 ... liquid crystal molecule, 350 ... spacer, 1000 ... mother TFT Substrate, 2000 ... Mother counter substrate, 2031 ... Degraded part of overcoat film

Claims (7)

Forming a TFT and a pixel electrode on a first substrate;
A light shielding film and three color filters are formed on the display area of the second substrate having a display area and a seal portion, an overcoat film is formed on the three color filters, and the light shield is formed on the seal portion. A step of laminating a film, a color filter of one color of the color filters, and an overcoat film;
Forming an alignment film material on the overcoat film in the display region, and not forming the alignment film material on the seal portion;
Irradiating the alignment film material in the display area of the second substrate and ultraviolet rays for performing photo-alignment treatment on the seal portion;
A method for manufacturing a liquid crystal display device, comprising: a step of bonding the first substrate and the second substrate with a sealing material in the seal portion. Forming a TFT and a pixel electrode on a first substrate;
A light shielding film and three color filters are formed on the display area of the second substrate having a display area and a seal portion, an overcoat film is formed on the three color filters, and the light shield is formed on the seal portion. A step of laminating a film, a color filter of a plurality of colors among the color filters, and an overcoat film;
Forming an alignment film material on the overcoat film in the display region, and not forming the alignment film material on the seal portion;
Irradiating the alignment film material in the display area of the second substrate and ultraviolet rays for performing photo-alignment treatment on the seal portion;
A method for manufacturing a liquid crystal display device, comprising: a step of bonding the first substrate and the second substrate with a sealing material in the seal portion.   One of the plurality of color filters formed on the seal portion is formed continuously with the color filter formed on the display area, and the other color filter of the plurality of color filters is formed on the display area. 3. The method of manufacturing a liquid crystal display device according to claim 2, wherein the liquid crystal display device is formed so as not to be continuous with the filter. Forming a TFT and a pixel electrode on a first substrate;
A light shielding film and three color filters are formed on the display area of the second substrate having a display area and a seal portion, an overcoat film is formed on the three color filters, and the light shield is formed on the seal portion. By laminating a film, a color filter of one color among the color filters, and an overcoat film, the one color filter is formed so as not to be continuous with any of the three color filters in the display region. Forming a step portion corresponding to an end portion of the one color filter in the overcoat film;
Forming an alignment film material on the overcoat film in the display region, and not forming the alignment film material on the seal portion;
Irradiating the alignment film material in the display area of the second substrate and ultraviolet rays for performing photo-alignment treatment on the seal portion;
A method for manufacturing a liquid crystal display device, comprising: a step of bonding the first substrate and the second substrate with a sealing material in the seal portion. Forming a TFT and a pixel electrode on a first substrate;
A light shielding film and three color filters are formed on the display area of the second substrate having a display area and a seal portion, an overcoat film is formed on the three color filters, and the light shield is formed on the seal portion. A film, a color filter of a plurality of colors among the color filters, and an overcoat film are stacked, and the color filters of the plurality of colors are formed so as not to be continuous with any of the three color filters of the display area Forming a step portion corresponding to an end portion of the color filters of the plurality of colors in the overcoat film,
Forming an alignment film material on the overcoat film in the display region, and not forming the alignment film material on the seal portion;
Irradiating the alignment film material in the display area of the second substrate and ultraviolet rays for performing photo-alignment treatment on the seal portion;
A method for manufacturing a liquid crystal display device, comprising: a step of bonding the first substrate and the second substrate with a sealing material in the seal portion. Forming a TFT and a pixel electrode on a first substrate;
A light shielding film and three color filters are formed on the display area of the second substrate having a display area and a seal portion, an overcoat film is formed on the three color filters, and the light shield is formed on the seal portion. A film, a color filter of one color among the color filters, and a step of laminating an overcoat film thicker than the display region;
Forming an alignment film material on the overcoat film in the display region, and not forming the alignment film material on the seal portion;
Irradiating the alignment film material in the display area of the second substrate and ultraviolet rays for performing photo-alignment treatment on the seal portion;
A method for manufacturing a liquid crystal display device, comprising: a step of bonding the first substrate and the second substrate with a sealing material in the seal portion.   The liquid crystal display device according to claim 6, wherein a film thickness of the overcoat film in the seal portion is formed to be 1.5 times or more of a film thickness of the overcoat film in the display region. Manufacturing method.

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