JP5731023B2 - Liquid crystal display - Google Patents

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, the application is expanding in various fields such as a large display device such as a TV, 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 better not to form a pretilt angle with respect to the liquid crystal molecules in the vicinity of the alignment film. Therefore, it is advantageous to form the alignment axis for the alignment film by the photo-alignment method, not 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. As a result, anisotropy for aligning liquid crystal molecules in the alignment film is 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. Such a problem is particularly problematic when the material irradiated with ultraviolet rays is an organic material.

  FIG. 8 is a cross-sectional view of a seal portion showing problems in the case where optical alignment is performed on the alignment film 113 in a liquid crystal display panel having a conventional structure. Hereinafter, the configuration of FIG. 8 is also referred to as Comparative Example 1. In FIG. 8, a liquid crystal layer 300 is sandwiched between a TFT substrate 100 on which a TFT or the like is formed and a counter substrate 200 on which a color filter 201 or the like is formed, and the liquid crystal layer 300 is sealed with a sealant 150. Although a detailed cross-sectional structure will be described later, a gate insulating film 102, an inorganic passivation film 106, and an interlayer insulating film 109 are formed on the TFT substrate 100 in the seal portion. On the counter substrate 200, a black matrix 202 and an overcoat film 203 are formed. The sealing material 150 is formed between the interlayer insulating film 109 and the overcoat film 203 of the TFT substrate 100. The alignment film 113 for aligning the liquid crystal is not formed on the seal material 150.

  FIG. 9 is a schematic diagram in the case where optical alignment is performed on the alignment film 113 of the counter substrate 200. In FIG. 9, the alignment film 113 is optically aligned by irradiating the counter substrate 200 on which the alignment film 113 is formed with polarized ultraviolet rays. Since the alignment film 113 is not formed on the seal portion 150, the overcoat film 203 is directly irradiated with ultraviolet rays. Then, the overcoat film 203 deteriorates due to ultraviolet rays, and an overcoat film deterioration portion 2031 is generated on the surface of the overcoat film 203. The overcoat film deterioration portion 2031 is likely to transmit moisture.

  On the other hand, on the TFT substrate 100 side, the interlayer insulating film 109 is exposed in a portion where the alignment film 113 is not formed. The interlayer insulating film 109 is made of SiN and is not deteriorated by ultraviolet rays. Therefore, even if the photo-alignment is performed by ultraviolet rays, the problem as shown in FIG. 9 does not occur on the TFT substrate 100 side.

  When a liquid crystal display panel is formed using the counter substrate 200 and the TFT substrate 100 formed as described above, an overcoat film degradation portion 2031 exists in the seal portion of the counter substrate 200 as shown in FIG. For this reason, moisture permeates from this portion, which deteriorates the life characteristics of the liquid crystal display panel. As a specific problem, the moisture that has entered the liquid crystal display panel expands, and the seal portion peels off.

  In FIG. 10, the alignment film 113 is formed up to the seal portion with respect to the TFT substrate 100 and the counter substrate 200 so as not to cause the overcoat film degradation portion 2031 in the counter substrate 200 as shown in FIG. 8. It is an example. Hereinafter, the configuration of FIG. 10 is also referred to as Comparative Example 2. When photo-alignment is performed on the counter substrate 200 as shown in FIG. 10, since the alignment film 113 is formed up to the seal portion, the overcoat film 203 is not deteriorated by ultraviolet rays.

  However, the configuration of FIG. 10 causes a problem of the adhesive force between the alignment film 113 and the interlayer insulating film 109 as shown in FIG. Liquid crystal display panels are subject to various vibrations and shocks during use. Therefore, if the adhesive force between the films is weak, peeling between the films occurs when vibration or the like is applied.

  10 or 11, the alignment film 113 is an organic film such as polyimide, and the interlayer insulating film 109 is an inorganic film such as SiN. In general, the adhesion between the organic film and the inorganic film is weak. On the other hand, since the sealing material 150 is an adhesive, the adhesive force between the sealing material 150 and the alignment film 113 is strong. In the counter substrate 200, both the overcoat film 203 and the alignment film 113 are organic films. Strong adhesion between organic film and organic film.

  When vibration or the like is applied to the liquid crystal display panel having such a configuration, the stress is generated in the seal portion. Therefore, peeling occurs between the alignment film 113 and the interlayer insulating film 109 in the seal portion on the TFT substrate 100 side. . This is because the alignment film 113 is an organic film, and the interlayer insulating film 109 is an inorganic film formed of SiN or the like, and the adhesive force therebetween is weak.

  Thus, it is not easy to achieve both a configuration that prevents moisture penetration and a configuration that can withstand vibration and impact. An object of the present invention is to realize a liquid crystal display panel having sufficient mechanical tolerance against vibration and the like, and preventing moisture penetration.

The present invention solves the above-described problems, and a specific configuration is as follows. That is,
(1) A TFT substrate having a first alignment film formed on an inorganic insulating film and an overcoat film formed on a black matrix, and a second alignment film formed on the overcoat film The liquid crystal display panel is bonded to the substrate by a sealing material at a sealing portion, and the sealing material is bonded to the inorganic insulating film without the first alignment film at the sealing portion on the TFT substrate side. In the sealing portion on the counter substrate side, the sealing material and the second alignment film are bonded, and the sealing material and the overcoat film are not bonded.

  (2) A TFT substrate in which a first alignment film is formed on an inorganic insulating film and an overcoat film formed on a black matrix, and a second alignment film formed on the overcoat film The liquid crystal display panel is bonded to the substrate by a sealing material at a sealing portion, and the sealing material on the TFT substrate side does not have the first alignment film, and the sealing material is the inorganic insulating film. In the seal portion on the counter substrate side, the seal material adheres to the second alignment film on the end portion side of the counter substrate with respect to the center of the seal portion, and in other portions, the seal The material is characterized in that it is bonded to the overcoat film.

  In this case, as another means, in the seal portion on the counter substrate side, the seal material is applied to the second alignment film in the first portion that is closer to the end portion of the counter substrate than the center of the seal portion. The sealing material adheres to the second alignment film in the second portion that is bonded and is closer to the center of the counter substrate than the center of the seal portion, and the first portion and the second portion Other than the above, the sealing material may be bonded to the overcoat film.

  (3) A TFT substrate having a first alignment film formed on an inorganic insulating film and an overcoat film formed on a black matrix, and a second alignment film formed on the overcoat film The liquid crystal display panel is bonded to the substrate by a sealing material at a sealing portion. In the sealing portion on the TFT substrate side, the sealing material is closer to the end portion side of the TFT substrate than the center of the sealing portion. In the other portion, the sealing material is bonded to the inorganic insulating film, and the counter substrate is closer to the counter substrate than the center of the seal portion. The sealing material is bonded to the second alignment film on the end portion side, and the sealing material is bonded to the overcoat film in other portions. That is, in the third means, the pattern of the first alignment film and the pattern of the second alignment film on the TFT substrate are the same.

  According to the first means of the present invention, when the photo-alignment treatment is performed by the ultraviolet rays, the ultraviolet rays are not directly applied to the overcoat film, so there is no deterioration of the overcoat film, and moisture from the deteriorated portion of the overcoat film. Can be prevented.

  According to the second means of the present invention, in the seal portion of the counter substrate, the seal material is partly adhered to the alignment film and the other part is adhered to the overcoat film. In the part where the sealing material is in direct contact with the overcoat film, the overcoat film is deteriorated when photo-aligned, but moisture is blocked at the part where the sealing material is bonded to the alignment film. Intrusion can be prevented. On the other hand, since the sealing material also has a portion that adheres to the overcoat film, it is possible to sufficiently secure the adhesive strength of the sealing material.

  According to the third means of the present invention, on the TFT substrate side, part of the sealing material is brought into contact with the alignment film, and the other part is brought into contact with the inorganic insulating film. Can be ensured at the same time, and the printing plate for alignment film printing can be made the same for the counter substrate and the TFT substrate, so that the manufacturing cost of the liquid crystal display panel can be reduced.

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. 6 is a cross-sectional view of a seal portion in a first form of Example 2. FIG. It is sectional drawing of the seal | sticker part in the 2nd form of Example 2. FIG. 6 is a cross-sectional view of a seal portion in a first form of Example 3. FIG. It is sectional drawing of the seal | sticker part in the 2nd form of Example 3. FIG. It is a table | surface which shows the effect of this invention. 6 is a cross-sectional view of a seal portion of Comparative Example 1. FIG. It is sectional drawing which shows the optical orientation process of a counter substrate. 10 is a cross-sectional view of a seal portion of Comparative Example 2. FIG. 10 is a cross-sectional view showing a problem of Comparative Example 2. FIG.

  Before describing an embodiment of the present invention, a configuration of an IPS liquid crystal display panel to which the present invention is applied will be described. FIG. 1 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 insulating film interposed therebetween. Yes. 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, it can also be applied to IPS type liquid crystal display devices other than FIG.

  In FIG. 1, 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. 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 impurities. 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. Through holes are formed in the organic passivation film.

  On the organic passivation film 107, the counter electrode 108 is formed of ITO (Indium Tin Oxide) which is a transparent conductive film. An interlayer insulating film 109 is formed of SiN so as to cover the counter electrode 108. The through hole 111 is formed by etching the interlayer insulating film 109 and the inorganic passivation film 106. Thereafter, ITO is deposited to cover the interlayer insulating film 109 and the through-hole 111 and serve as the pixel electrode 110, and patterning is performed.

  The pixel electrode 110 is a so-called comb-like electrode. A slit 112 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. The alignment treatment for the alignment film 113 is optical alignment with polarized ultraviolet rays.

  In the example of FIG. 1, 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. 1, a counter substrate 200 is provided with a liquid crystal layer 300 interposed therebetween. A color filter is formed inside the counter substrate 200. The black matrix 202 improves the contrast of the image and has a role as a light shielding film of the TFT, and prevents a photocurrent from flowing through the TFT.

  An overcoat film 203 is formed to cover the color filter 201 and the black matrix 202. Since the surface of the color filter 201 and the black matrix 202 is uneven, the surface is flattened by the overcoat film 203. An alignment film 113 for determining the initial alignment of the liquid crystal molecules 301 is formed on the overcoat film 203. The alignment film 113 is subjected to photo-alignment processing.

  On the outside of the counter substrate 200, an external conductive film 210 is formed by sputtering ITO. The external conductive film 210 is formed in order to stabilize the electric field inside the liquid crystal display panel.

  FIG. 2 is a cross-sectional view of the seal portion of the liquid crystal display panel in this embodiment, and is a cross-sectional view of the seal portion of the IPS liquid crystal display panel described in FIG. In FIG. 2, the external conductive film formed on the counter substrate 200 is omitted.

  In FIG. 2, a gate insulating film 102, an inorganic passivation film 106, an organic passivation film 107, an interlayer insulating film 109, and an alignment film 113 are stacked on the TFT substrate 100. The organic passivation film 107 planarizes the display area and does not extend to the seal portion. An interlayer insulating film 109 formed on the organic passivation film 107 extends to the end of the TFT substrate 100. An alignment film 113 is formed so as to cover the interlayer insulating film 109.

  A color filter 201 and a black matrix 202 are formed on the counter substrate 200 side in FIG. 2, and an overcoat film 203 is formed so as to cover them. On the overcoat film 203, columnar spacers 160 for defining the distance between the TFT substrate 100 and the counter substrate 200 are formed. An alignment film 113 is formed to cover the overcoat film 203 and the columnar spacer 160. The TFT substrate 100 and the counter substrate 200 are sealed with a sealing material 150 and filled with liquid crystal. For example, an epoxy resin is used for the sealing material 150.

  The alignment film 113 on both the TFT substrate 100 side and the counter substrate 200 side is subjected to an alignment process by optical alignment. The feature of this embodiment is that the alignment film 113 on the counter substrate 200 side is formed up to the end of the counter substrate 200, but the alignment film 113 on the TFT substrate 100 side is not formed up to the lower part of the sealing material 150. That is. In FIG. 2, when the alignment film 113 on the counter substrate 200 side is photo-aligned with ultraviolet rays, the overcoat film 203 is not deteriorated because the overcoat film 203 is entirely covered with the alignment film 113. Therefore, there is no problem that moisture enters from a deteriorated portion of the overcoat film 203 and impairs the reliability of the liquid crystal display panel.

  On the other hand, on the TFT substrate 100 side, the alignment film 113 is formed in the display region, but is not formed up to the seal portion. In this case, the interlayer insulating film 109 in the seal portion that is not covered with the alignment film 113 is irradiated with ultraviolet rays during photo-alignment. However, since the interlayer insulating film 109 is formed of an inorganic film such as SiN, it does not deteriorate due to ultraviolet rays.

  According to the structure of FIG. 2, since there is no portion that deteriorates due to photo-alignment ultraviolet rays on the TFT substrate 100 side or the counter substrate 200 side, it is possible to prevent moisture from entering from the seal portion. In the structure of FIG. 2, there is no problem of film peeling at the seal portion due to mechanical vibration or the like. That is, on the TFT substrate 100 side, all of the insulating layers in the seal portion are inorganic films, and their mutual adhesive strength is strong. On the counter substrate 200 side, the layer structure in the seal portion is an organic film, and the adhesive strength between them is strong. Further, the sealing material 150 is an adhesive, and has high adhesive strength with both the alignment film 113 on the counter substrate 200 side and the SiN film on the TFT substrate 100 side.

  Thus, according to Example 1, moisture intrusion due to deterioration of the overcoat film 203 can be prevented, and film peeling due to mechanical vibration or the like does not occur.

  FIG. 3 is a sectional view showing a second embodiment according to the present invention. In FIG. 3, the description of the same configuration as in FIG. 2 is omitted. In the counter substrate 200 of FIG. 3, the alignment film 113 is formed on the display region and the end of the counter substrate 200, but the portion where the sealing material 150 is formed is the alignment film except for the end of the counter substrate 200. 113 is not formed.

  When a photo-alignment process is performed on such a counter substrate 200, a portion of the overcoat film 203 that is not covered with the alignment film 113 is deteriorated by ultraviolet rays. However, since there is a portion A where the alignment film 113 is formed so as to overlap the portion where the sealing material 150 is formed, the overcoat film 203 is not deteriorated in this portion. Accordingly, moisture from the outside is blocked at the portion A, so that the inside of the liquid crystal display panel is protected from moisture intrusion.

  The adhesive force between the sealing material 150 and the alignment film 113 is weaker than the adhesive force between the sealing material 150 and the overcoat film 203. In this embodiment, since the sealing material 150 and the overcoat film 203 are in contact with each other over a wide range, the mechanical strength against vibration or the like is stronger than that in the first embodiment.

  FIG. 4 is a cross-sectional view showing another embodiment of the second embodiment. FIG. 4 differs from FIG. 3 in the configuration of the seal portion of the counter substrate 200. In FIG. 4, the alignment film 113 overlaps inside and outside the sealing material 150. When the counter substrate 200 shown in FIG. 4 is photo-aligned, the portion of the overcoat film 203 that is not covered with the alignment film 113 is deteriorated by ultraviolet rays.

  However, there are portions A and B where the sealing material 150 and the alignment film 113 overlap on the inner side and the outer side of the sealing material 150. In this portion, the alignment film 113 is not deteriorated. In B and B, it is possible to prevent moisture from entering from the outside. Further, in the portion where the alignment film 113 does not overlap the sealing material 150, the sealing material 150 and the overcoat film 203 are in direct contact with each other, so that the adhesive force with the sealing material 150 is strong.

  As described above, also in this embodiment, it is possible to realize a liquid crystal display panel that prevents moisture from entering from the outside and has high mechanical strength against vibration and the like. Compared with the first embodiment of the present embodiment, the present embodiment has a higher blocking ability against moisture intrusion, but the strength against mechanical vibration and the like is inferior to the first embodiment. However, any of the embodiments is within the practical range.

  FIG. 5 is a sectional view showing a third embodiment according to the present invention. 5 differs from FIG. 3 in the configuration of the TFT substrate 100 in the seal portion. In the TFT substrate 100 of FIG. 5, the alignment film 113 is formed on the display region and the end of the counter substrate 200, but the alignment film 113 is not formed on the portion where the sealing material 150 is formed except outside. . That is, in FIG. 5, the formation range of the alignment film 113 is the same range for the TFT substrate 100 and the counter substrate 200.

  The alignment film 113 is generally formed by flexographic printing. If the counter substrate 200 and the TFT substrate 100 have the same formation range of the alignment film 113, only one printing plate is required. On the other hand, in Example 1 and Example 2, two flexographic printing plates for the TFT substrate 100 and the counter substrate 200 are required. In this respect, this example is superior to Examples 1 and 2 in mass productivity.

  In FIG. 5, the function on the counter substrate 200 side is the same as that described in the second embodiment. On the TFT substrate 100 side, there is a portion where the sealing material 150 and the alignment film 113 overlap on the outside, while in the other portion, the sealing material 150 and the interlayer insulating film 109 formed of SiN are directly connected. In contact. Therefore, the adhesive force between the sealing material 150 and the TFT substrate 100 is sufficiently strong.

  FIG. 6 is a cross-sectional view showing a second embodiment of the present embodiment. In FIG. 6, the counter substrate 200 side is the same as FIG. 4, which is the second embodiment of Example 2. Therefore, the function on the counter substrate 200 side is the same as that described in the second embodiment of the second embodiment. On the other hand, the formation range of the alignment film 113 on the TFT substrate 100 side in FIG. 6 is the same as the formation range of the alignment film 113 on the counter substrate 200 side.

  On the counter substrate 200 side in FIG. 6, the intrusion of moisture from the outside is blocked in the seal portion at the portion where the alignment film 113 and the overcoat film 203 overlap, that is, the A portion and the B portion. Further, the adhesive force between the counter substrate 200 and the sealing material 150 is ensured in the portion where the sealing material 150 and the overcoat film 203 are in direct contact. In the TFT substrate 100 of FIG. 6, the adhesive force is ensured in the portion where the sealing material 150 and the interlayer insulating film 109 made of SiN are in direct contact.

  As described above, in any of the embodiments of the present embodiment, it is possible to ensure the strength against moisture intrusion into the liquid crystal display panel and mechanical vibration.

  FIG. 7 is a table showing a comparison between each embodiment of the present invention described above and the structure of the comparative example described in the section “Problems to be solved by the invention”. 8 described in “Problems to be Solved by the Invention” is Comparative Example 1, and FIG. 10 is Comparative Example 2. Example 2 in FIG. 7 has the configuration shown in FIG. 3, and Example 3 has the configuration shown in FIG.

  In FIG. 7, PCT (Pressure Cooker Test) is performed as a test for evaluating resistance to moisture, and a vibration test is performed as a test for evaluating mechanical strength. The PCT test evaluates how many hours have passed in an environment of a temperature of 120 ° C., 2 atm, and a humidity of 100%. The vibration test is an evaluation of how many times the impact of gravity is applied by applying vibration in a vibration testing machine to cause film peeling. In FIG. 7, the pass / fail judgment is made based on 20 hours for the PCT test and 1.5 G for the mechanical strength. In the determination, “◯” indicates pass and “×” indicates failure.

  In FIG. 7, in Comparative Example 1, the mechanical strength is 2.5 G, but the PCT resistance is 10 hours, which is not sufficient. That is, it is considered that moisture has entered from the portion of the overcoat film 203 that has deteriorated due to ultraviolet irradiation. In Comparative Example 2, although the PCT resistance was 50 hours, the mechanical strength was 1.5 G, which was a pass / fail boundary, and was judged not sufficient. This is probably because the adhesive force between the alignment film 113 and the interlayer insulating film 109 on the TFT substrate side is not sufficient in the seal portion.

  In Example 1, the PCT resistance is 50 hours, which is an acceptable range. In the configuration of Example 1, it is considered that there is no deterioration of the overcoat film 203. The mechanical strength is 2G, which is an acceptable range. However, the mechanical strength is inferior to the other examples. This is considered because the sealing material 150 is in contact with only the alignment film 113 on the counter substrate 200 side.

  In Example 2, the PCT resistance is 50 hours, the mechanical strength is 2.5 G, and both are acceptable. In FIG. 3 in Example 2, it is shown that moisture from the outside is sufficiently blocked in the portion A where the overcoat film 203, the alignment film 113, and the sealing material 150 overlap. Further, since the sealing material 150 and the overcoat film 203 are in direct contact with each other, it is shown that the adhesive strength of the sealing material 150 is sufficiently ensured.

  In Example 3, the PCT resistance is 50 hours, the mechanical strength is 2.5 G, and all are acceptable. FIG. 5 in Example 3 shows that moisture from the outside is sufficiently blocked in the portion A where the overcoat film 203, the alignment film 113, and the sealing material 150 overlap. In Example 3, the sealing material 150 and the alignment film 113 partially overlap each other on the TFT substrate 100 side, but this influence shows little influence on the mechanical strength.

  As described above, in any of the configurations of Examples 1 to 3, the PCT resistance, mechanical strength, and the like are within acceptable ranges, and the reliability of the liquid crystal display panel can be ensured.

  DESCRIPTION OF SYMBOLS 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 ... sealing material, 160 ... columnar spacer, 200 ... counter substrate, 201 ... color filter, 202 ... black matrix, 203 ... Overcoat film, 210 ... external conductive film, 300 ... liquid crystal layer, 301 ... liquid crystal molecule, 2031 ... deteriorated part of overcoat film

Claims (7)

A TFT substrate on which an inorganic insulating film and a first alignment film are formed;
A counter substrate on which an overcoat film and a second alignment film are formed;
A liquid crystal display device in which the TFT substrate and the counter substrate are bonded by a sealing material,
The first alignment film and the second alignment film are organic films and have undergone a photo-alignment process,
The overcoat film is disposed closer to the counter substrate than the second alignment film;
In the predetermined cross section of the liquid crystal display device, the second alignment film has a first portion provided on an end side of the counter substrate with respect to the center of the seal material and the counter portion with respect to the center of the seal material. A second portion provided on the center side of the substrate and spaced apart from the first portion;
The first portion has a portion overlapping with the sealing material and a portion not overlapping with the sealing material,
The liquid crystal display panel, wherein the sealing material overlaps the overcoat film at a location where the first portion and the second portion are separated from each other.   The liquid crystal display device according to claim 1, wherein the second portion has a portion overlapping with the sealing material and a portion not overlapping with the sealing material. The between the overcoat film and said counter substrate, the liquid crystal display device according to claim 1 or 2, characterized in that the black matrix is formed.   4. The liquid crystal display device according to claim 1, wherein the first alignment film and the sealing material do not overlap with each other in the predetermined cross section. In the predetermined cross section, the first alignment film includes a third portion provided on an end side of the TFT substrate with respect to the center of the sealing material, and a center side of the TFT substrate with respect to the center of the sealing material. A fourth portion spaced from the third portion, and
5. The liquid crystal according to claim 1, wherein the third portion has a portion overlapping with the sealing material and a portion not overlapping with the sealing material. Display device.   The liquid crystal display device according to claim 5, wherein the fourth portion has a portion overlapping with the sealing material and a portion not overlapping with the sealing material.   7. The liquid crystal display device according to claim 5, wherein the first alignment film and the second alignment film are formed in the same pattern.

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