JP2008096574A - Liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal cell of which the yield is improved, by suppressing occurrence of defects caused by separation of a coloring layer and inclusion of impurities. <P>SOLUTION: A protruding region 33 protruding outward is arranged on a corner part of an outer edge region 32 of a first coloring layer 13 which surrounds outer edges of coloring layers 14, 15. The separation of the first coloring layer 13 from the array substrate is prevented by increasing an adhesion area with the protruding region 33. A liquid crystal material injected into the liquid crystal cell through a liquid crystal injection port flows into the protruding region 33 (a recess 35) and the impurities etc. move to the recess 35 together with the liquid crystal material and are accumulated therein. The defects caused by the impurities are suppressed and the yield of the liquid crystal cell is improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display element provided with a plurality of colored layers provided in a grid pattern corresponding to each pixel.

  In recent years, a liquid crystal cell, which is a liquid crystal display element widely used as a display device in various devices such as mobile phones and notebook computers, includes a thin film transistor (TFT) at each intersection of a plurality of scanning lines and a plurality of signal lines, The liquid crystal display device includes an array substrate on which liquid crystal pixel portions each including a liquid crystal capacitor and an auxiliary capacitor are arranged, and a drive circuit that drives scanning lines and signal lines.

  In addition, with the development of integrated circuit technology and the practical application of process technology, a part of the drive circuit can be formed on the array substrate, and the entire liquid crystal cell is reduced in size and thickness.

  Conventionally, three colored layers of a first colored layer to a third colored layer are provided in a display region on an array substrate constituting such a liquid crystal cell.

  Of these three colored layers, the first colored layer is formed so as to have a stripe shape of a vertical stripe pattern in the display region and an outer peripheral region surrounding the display region.

  However, the first outermost colored layer formed in this manner has a narrow adhesion area with the base, so that the adhesive strength is reduced, and the first colored layer may be peeled off during the development process when forming the colored layer, which may reduce the yield. There is a problem.

Therefore, in order to prevent such peeling, it is effective to increase the adhesion area between the first colored layer and the base by making the first colored layer a grid pattern that develops in the vertical and horizontal directions (for example, Patent Documents). 1).
JP 2001-337345 A

  However, when the lattice pattern as described above has a high density (high definition), the second colored layer is formed by the lattice pattern formed by the first colored layer when the second colored layer is applied by, for example, a spin coater. Since the resistance in a direction that prevents the spread of the resin in the centrifugal force direction increases, uneven coating occurs in a specific direction.

  The angle at which the coating unevenness occurs is greatly influenced by the arrangement of the grid pattern. That is, when applying with a spin coater, the resist flows in all directions, but if the lattice pattern is aligned in a certain angle direction, the resistance in that direction becomes high, and the resist becomes difficult to flow. For this reason, the coating film thickness is reduced only in this direction, and is identified as coating unevenness.

  Therefore, when the grid pattern is dispersed in the case direction, the occurrence of coating unevenness can be suppressed, but the adhesion area of the first colored layer is small, and it becomes easy to peel off.

  In addition, when a liquid crystal material is vacuum-injected from the liquid crystal injection port, the liquid crystal material is contaminated by impurities such as dust existing in the liquid crystal injection port and the liquid crystal display element, and near the corner of the liquid crystal display element far from the liquid crystal injection port. Impurities accumulate, point defects and display unevenness due to these impurities occur, and the yield may decrease.

  The present invention has been made in view of these points, and an object of the present invention is to provide a liquid crystal display element in which the yield is improved by suppressing peeling of a colored layer and defects caused by impurities.

  The present invention relates to an array substrate, a counter substrate disposed opposite to the array substrate, a liquid crystal layer made of a liquid crystal material and interposed between the array substrate and the counter substrate, the array substrate and the counter substrate A liquid crystal injection port through which the liquid crystal material can be injected, and the array substrate includes a plurality of pixels provided in a matrix and a plurality of colored layers provided corresponding to the pixels, respectively. The one colored layer includes a rectangular frame-shaped outer peripheral region surrounding an outer periphery of the other colored layer, and a projecting region projecting outward at at least one corner of the outer peripheral region. It is what it has.

  And the protrusion area | region protrudes outward in the at least 1 corner | angular part of the square frame-shaped outer periphery area | region of one colored layer surrounding the outer periphery of another colored layer.

  According to the present invention, the protruding area can increase the adhesion area to prevent the colored layer from peeling off from the array substrate, and when the liquid crystal material is injected from the liquid crystal injection port, impurities and the like protrude outward from the colored layer. In the vicinity of the protruding region, defects caused by impurities can be suppressed, and the yield can be improved.

  Hereinafter, the configuration of the liquid crystal display element according to the first embodiment of the present invention will be described with reference to FIGS.

  2 and 3, reference numeral 1 denotes a liquid crystal cell as a liquid crystal display element. The liquid crystal cell 1 includes an array substrate 2, a counter substrate 3 disposed opposite to the array substrate 2, and a space between the substrates 2 and 3. The distance between the substrates 2 and 3 is held by spacer columns 5 made of, for example, resin. The array substrate 2 and the counter substrate 3 are bonded to each other by a UV seal 7 disposed so as to surround the outer periphery excluding the liquid crystal injection port 6 for injecting the liquid crystal material C (FIG. 4) constituting the liquid crystal layer 4. .

  In the array substrate 2, a thin film transistor 12 (hereinafter referred to as TFT 12) as a switching element is formed on one main surface of a light-transmitting insulating substrate 11, and a first colored layer 13 as a colored layer is formed thereon. A second colored layer 14 as a layer and a third colored layer 15 as a colored layer are respectively disposed. Further, pixel electrodes 16, 17, and 18 having translucency are formed on the colored layers 13, 14, and 15, respectively. The pixel electrodes 16, 17, and 18 are formed on the colored layers 13, 14 and 14, respectively. , 15 are electrically connected to the TFT 12 through through-holes 21, 22, 23 formed therein.

  Further, an alignment film (not shown) is formed on the colored layers 13 to 15 including the pixel electrodes 16 to 18, and the display area 25 for screen display having the pixels 24 in a matrix is formed in a square shape by such a configuration. Has been.

  Further, in the vicinity of the inner edge of the UV seal 7 which is the outer periphery of the display area 25, a BM layer 27 which is a light shielding layer as a non-display area is formed in a rectangular frame shape. The BM layer 27 is formed to be thicker by 1.5 μm to 2.0 μm, for example, than the colored layers 13 to 15.

  The colored layers 13 to 15 are formed in a stripe pattern with a vertical stripe pattern. Further, as shown in FIG. 1, the first colored layer 13 includes a lattice portion 31 formed so as to intersect with the second colored layer 14 and the third colored layer 15, and a quadrangle surrounding each colored layer 14, 15. A frame-shaped outer peripheral region 32 and a protruding region 33 formed to protrude toward the BM layer 27 at one corner of the outer peripheral region 32 are provided.

  The lattice portion 31 is formed so as to cross the second colored layer 14 and the third colored layer 15 at intervals between a plurality of pixels in the vertical and vertical directions in the figure at a position between the vertical directions of the pixels 24 in the horizontal and horizontal directions in the figure. The pixel 24 has a similar pattern every two columns. Accordingly, the lattice portions 31 in the adjacent rows are displaced in the vertical direction and are configured not to be adjacent to each other.

  The outer peripheral region 32 is formed along the inner edge portion of the BM layer 27 and has a width dimension smaller than that of the first colored layer 13 provided in the pixel 24 (FIG. 2).

  The protruding region 33 is located in a recess 35 formed by cutting out at a corner of the BM layer 27. Therefore, the protruding area 33 is provided to protrude outward from the display area 25. Further, the protruding region 33 is a corner other than the corner closest to the liquid crystal inlet 6, that is, the corner of the outer peripheral region 32 nearest to the liquid crystal inlet 6 in the present embodiment in FIG. The upper left corner in FIG. 3, which is a corner located diagonally with respect to the lower right corner, in other words, the corner farthest from the liquid crystal inlet 6.

  Here, the size of the protruding region 33 is preferably set in accordance with the degree of peeling of the outer peripheral region 32 and the pixel size. In this embodiment, for example, 10 pixels in the vertical direction and 5 in the horizontal direction. Over the pixel, it is provided in an L shape in plan view.

  On the other hand, as shown in FIG. 2 and FIG. 3, the counter substrate 3 has a counter electrode 42 which is a common electrode having translucency formed on one main surface of an insulating substrate 41 having translucency. An alignment film (not shown) is formed so as to cover the electrode 42.

  The liquid crystal layer 4 is interposed between the alignment film on the array substrate 2 side and the alignment film on the counter substrate 3 side.

  The spacer column 5 is formed in a columnar shape using, for example, a transparent resin.

  The edge of the liquid crystal injection port 6 is partitioned by a UV seal 7 and is sealed with a sealing material 45 formed of, for example, an ultraviolet curable resin.

  Next, the manufacturing method of the first embodiment will be described.

First, when manufacturing the array substrate 2, a TFT 12 is formed on the insulating substrate 11, and a blue resist solution is applied on the TFT 12 as a spinner, prebaked at about 90 ° C. for about 5 minutes, and using a predetermined mask pattern, 150 mJ Exposure with ultraviolet light having an intensity of / cm ² .

  Next, the first colored layer 13 is developed by developing with an aqueous solution of about 0.1 wt% TMAH (tetramethylammonium hydride) for about 40 seconds, further washing with water and post-baking at about 200 ° C. for about 1 hour. Form.

  At this time, by using a predetermined mask pattern, the lattice portion 31, the outer peripheral region 32, and the protruding region 33 are formed in the first colored layer 13, respectively.

  Thereafter, the second colored layer 14 and the third colored layer 15 are formed in the same process using a green resist solution and a red resist solution.

  Further, ITO is deposited on each of the colored layers 13 to 15 by a sputtering method and patterned to form pixel electrodes 16 to 18.

  In addition, the BM layer 27 is formed using a black resin and the columnar spacer columns 5 are formed using a transparent resin by the same process as the formation of the colored layers 13 to 15. Thereafter, an alignment film material made of polyimide is applied to the entire surface of the substrate, an alignment process is performed to form an alignment film, and the array substrate 2 is obtained.

  On the other hand, in manufacturing the counter substrate 3, ITO is deposited on the insulating substrate 41 by a sputtering method to form the counter electrode 42, and then an alignment film material made of polyimide is applied to the entire surface of the insulating substrate 41 and subjected to an alignment process. Then, an alignment film is formed to obtain the counter substrate 3.

  Next, a UV seal 7 is applied to the outer periphery of the counter substrate 3 except for the liquid crystal injection port 6 (FIG. 3) for liquid crystal injection, and then the array substrate 2 and the counter substrate 3 are bonded together by the UV seal 7. The liquid crystal cell 1 in an empty state is completed by putting it in a single wafer type sealing jig and exhausting it, followed by baking at a curing temperature of about 170 ° C. for 30 minutes.

  Further, after the liquid crystal material C to which the chiral material is added is vacuum-injected into the liquid crystal cell 1 from the liquid crystal injection port 6, the liquid crystal injection port 6 is sealed with the ultraviolet curable resin as the sealing material 45. The liquid crystal cell 1 is completed by attaching polarizing plates (not shown) to the main surface.

  Next, the effects of the first embodiment will be listed.

  Protruding regions 33 projecting outward are provided at the corners of the outer peripheral region 32 of the first colored layer 13 surrounding the outer periphery of the colored layers 14, 15, thereby increasing the adhesion area by the projecting regions 33 and performing the first coloring. The layer 13 can be prevented from peeling off from the array substrate 2, and the liquid crystal material C injected from the liquid crystal injection port 6 flows into the protruding region 33 (recess 35), and is present in the vicinity of the liquid crystal injection port 6 and in the liquid crystal cell 1. D or the like moves to and accumulates in the recess 35 together with the liquid crystal material C, so that the contamination of the liquid crystal layer 4 due to the impurities D or the like can be prevented, and the protruding region 33 (recess 35) is located outside the display region 25. Since it is located in a certain non-display area, that is, in the BM layer 27, defects caused by the accumulated impurities D, such as point defects and display unevenness, are not observed.

  As a result, the yield of the liquid crystal cell 1 can be improved.

  In particular, since the first colored layer 13 is most easily peeled off from the corner of the outer peripheral region 32, the first colored layer 13 can be reliably prevented from peeling off by providing the protruding region 33 at the corner.

  In addition, since the protruding region 33 is formed by the first colored layer 13 having a thickness smaller than that of the BM layer 27, the liquid crystal material C easily flows into the protruding region 33 (recess 35).

  Further, by providing the protruding region 33 at the farthest corner of the outer peripheral region 32 with respect to the liquid crystal injection port 6, as shown in FIG. 4, the liquid crystal material C injected from the liquid crystal injection port 6 has the protruding region 33 (recessed portion 33). 35), the impurities D together with the liquid crystal material C are more likely to accumulate in the protruding region (recess 35).

  Then, by setting the vertical and horizontal dimensions of the protruding region 33 corresponding to the pixel 24, it is possible to obtain a good display while preventing the first colored layer 13 from being peeled off from the outer peripheral region 32. it can.

  In addition, when the second colored layer 14 and the third colored layer 15 are applied by shifting the positions of the lattice portions 31 in the adjacent rows so as not to be adjacent to each other in the vertical direction, the first colored layer The grid portion 31 formed of 13 does not increase the resistance in the direction that prevents the second colored layer 14 from spreading in the centrifugal force direction, and the pattern of the colored layers 13, 14, and 15 has a high density (high definition). Even in such a case, it is possible to disperse the occurrence of uneven coating of the colored layers 14 and 15, and to suppress deterioration in display quality.

  Furthermore, by forming the protruding region 33 in blue with low luminance, a reduction in contrast can be suppressed.

  And since the protrusion area | region 33 can be formed simultaneously with the 1st colored layer 13 only by changing the shape of a predetermined mask pattern, a manufacturing man-hour does not increase.

  In the first embodiment, for example, as in the second embodiment shown in FIG. 5, the shape of the protruding region 33 is set so that the impurity D easily flows together with the liquid crystal material C. A shape that protrudes outward from the outer peripheral region 32 along the diagonal direction, or a shape that extends in the vertical direction at the side of the outer peripheral region 32 as in the third embodiment shown in FIG. Even if it does, it can have the same effect as said 1st Embodiment.

  Further, the protruding regions 33 may be provided at a plurality of corners of the outer peripheral region 32. For example, when the liquid crystal injection port 6 is located at the middle portion of the long side of the liquid crystal cell 1 in the left-right direction, the protruding regions 33 are respectively formed at the corners located at both ends of the opposite long side of the liquid crystal cell 1. By further providing the adhesive area, the peeling of the first colored layer 13 can be more reliably prevented, and the impurities D and the like can be reliably accumulated together with the liquid crystal material C in the protruding region 33 (recess 35). Can do.

  In each of the above embodiments, the first colored layer 13 is a blue layer, the second colored layer 14 is a green layer, and the third colored layer 15 is a red layer. The colors of these colored layers 13 to 15 are arbitrary. Can be selected.

  Further, if the colored layer has a plurality of colors, two colors or four or more colors can be used.

  Furthermore, the position and shape of the protruding region 33 are not limited as long as the protruding region 33 is provided in at least one corner of the outer peripheral region 32.

It is a top view which expands and shows the principal part of the liquid crystal display element of the 1st Embodiment of this invention. It is explanatory sectional drawing which shows the principal part of a liquid crystal display element same as the above. It is a top view which shows a liquid crystal display element same as the above. It is explanatory drawing which shows the state which injected the liquid-crystal material of the liquid crystal display element same as the above from the liquid-crystal injection hole. It is a top view which expands and shows the principal part of the liquid crystal display element of the 2nd Embodiment of this invention. It is a top view which expands and shows the principal part of the liquid crystal display element of the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal cell as a liquid crystal display element 2 Array substrate 3 Counter substrate 4 Liquid crystal layer 6 Liquid crystal inlet
13 First colored layer as colored layer
14 Second colored layer as colored layer
15 Third colored layer as colored layer
24 pixels
32 Peripheral area
33 Projection area C Liquid crystal material

Claims (4)

An array substrate;
A counter substrate disposed opposite to the array substrate;
A liquid crystal layer composed of a liquid crystal material and interposed between the array substrate and the counter substrate;
A liquid crystal injection port capable of injecting the liquid crystal material between the array substrate and the counter substrate;
The array substrate is
A plurality of pixels provided in a matrix;
A plurality of colored layers provided corresponding to each of these pixels,
One of the colored layers is
A rectangular frame-shaped outer peripheral region surrounding the outer periphery of the other colored layer;
A liquid crystal display element comprising: a projecting region projecting outward at at least one corner of the outer peripheral region. The liquid crystal display element according to claim 1, wherein the protruding region is provided at least in any corner other than the corner closest to the liquid crystal injection port in the outer peripheral region. The liquid crystal injection port is located near one corner of the outer peripheral region,
The liquid crystal display element according to claim 2, wherein the protruding region is provided at a corner located diagonally to the one corner. The liquid crystal display element according to claim 1, wherein the protruding region is provided at a plurality of corners of the outer peripheral region.

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