JP2008015371A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device which has satisfactory quality without bringing about deterioration of a production yield. <P>SOLUTION: The liquid crystal display device is provided with: a seal material 110 which secures an injection port 111 for injecting liquid crystal material, is arranged on a seal part 115 surrounding an active area 120 and bonds an array substrate and a counter substrate to each other, wherein, on a flattening film, a plurality of grooves 242 extended toward seal parts 115A, 115B which face each other via the injection port 111 are formed, and an obstruction pattern 140 which is arranged at least between the grooves along the inner edge 115IN of the seal part 115 of demarcating the injection port 111 and obstructs the spreading of the seal material 110 is disposed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having a structure that suppresses the spread of a sealing material for bonding a pair of substrates.

  A typical liquid crystal display device as a flat display device includes a liquid crystal display panel configured by holding a liquid crystal layer between an array substrate and a counter substrate bonded together with a sealant. This liquid crystal display panel includes an active area constituted by display pixels in a matrix form.

  The sealing material is arranged so as to secure an injection port for injecting the liquid crystal material. The liquid crystal layer is formed by injecting a liquid crystal material from the injection port into the gap between the array substrate and the counter substrate, and then sealing the injection port with a sealing material. In the liquid crystal display panel having such a configuration, there is a problem that an excessive amount of sealing material enters the active area from the injection port and causes pixel defects.

In order to solve such a problem, a technique has been proposed in which a groove for preventing the sealing material from flowing into a portion of the surface of the substrate outside the active area of the injection port is provided (see, for example, Patent Document 1). .
JP 2002-214628 A

  Although the technique described above can suppress the flow of the sealing material into the active area, it is difficult to suppress the excessive spread of the sealing material. That is, since the sealing material is applied to one substrate and then pressed in a state where the other substrate is disposed facing the substrate, the sealing material spreads in a direction orthogonal to the extending direction (that is, the width direction of the sealing material). In particular, in the injection port, by providing the groove as described above, the gap between the groove and the substrate facing the substrate is enlarged, while the substrate facing the portion where the groove is not formed (for example, between the grooves) The gap between is apparently reduced. Since the sealing material tends to spread toward a region having a small gap due to capillary action, it tends to flow along the grooves. Although the spread of the sealing material is considered to some extent, the excessive spread causes a reduction in the inlet.

  When the inlet is reduced, problems such as poor injection of liquid crystal material and variations in injection time occur. For this reason, there is a possibility that the quality and manufacturing yield of the liquid crystal display panel may be significantly adversely affected.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a liquid crystal display device of good quality without causing a decrease in manufacturing yield.

A liquid crystal display device according to an aspect of the present invention includes:
Comprising an active area composed of a plurality of display pixels,
A first substrate comprising: a planarizing film disposed on the substrate; and a pixel electrode disposed on each of the display pixels on the planarizing film;
A second substrate having a counter electrode facing each of the pixel electrodes;
A sealing material that secures an injection port for injecting a liquid crystal material and is disposed in a seal portion that surrounds the active area, and bonds the first substrate and the second substrate;
A liquid crystal layer made of a liquid crystal material held between the first substrate and the second substrate,
In the planarizing film, a plurality of rows of grooves extending toward the seal portion facing each other across the injection port are formed,
In addition, a blocking pattern is provided which is disposed at least between the grooves along the inner edge of the seal portion defining the injection port, and prevents the seal material from spreading.

  According to the present invention, it is possible to provide a liquid crystal display device of good quality without causing a decrease in manufacturing yield.

  Hereinafter, a display device, particularly a liquid crystal display device according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the liquid crystal display device includes a liquid crystal display panel 100. That is, the liquid crystal display panel 100 includes a pair of substrates, that is, an array substrate (first substrate) 200 and a counter substrate (second substrate) 300, a liquid crystal layer 400 held between the array substrate 200 and the counter substrate 300, It is constituted by. The array substrate 200 and the counter substrate 300 are bonded to each other by a sealing material 110, and a predetermined gap for holding the liquid crystal layer 400 is formed therebetween. The liquid crystal display panel 100 includes an active area 120 that displays an image on the inner side surrounded by the sealing material 110. The active area 120 is composed of a plurality of display pixels PX arranged in a matrix.

  The array substrate 200 extends in the active area 120 along the column direction of the display pixels PX and the plurality of scanning lines Y (1, 2, 3,..., M) extending along the row direction of the display pixels PX. A plurality of existing signal lines X (1, 2, 3,..., N), a switch element 220 arranged at an intersection of the signal line X and the scanning line Y in each display pixel PX, and each display pixel PX And a pixel electrode 230 connected to the switch element 220.

  The gate electrode 222 of the switch element 220 is connected to the scanning line Y (or the gate electrode 222 is formed integrally with the scanning line Y). The source electrode 225 of the switch element 220 is connected to the signal line X (or the source 225 is formed integrally with the signal line X). The drain electrode 227 of the switch element 220 is connected to the pixel electrode 230.

  The counter substrate 300 includes a counter electrode 330 common to the plurality of display pixels PX in the active area 120.

  In addition, the liquid crystal display panel 100 includes a connection part 131 disposed on the outer peripheral part 130 located outside the active area 120. The connection portion 131 can be connected to a driving IC chip or a flexible wiring board that functions as a signal supply source. In the example shown in FIG. 1, the connection portion 131 is disposed on the extending portion 200 </ b> A of the array substrate 200 that extends outward from the end portion 300 </ b> A of the counter substrate 300.

  Each of the scanning lines Y (1, 2, 3,..., M) arranged in the active area 120 is connected to the connection part 131 via the outer peripheral part 130. Similarly, each of the signal lines X (1, 2, 3,..., N) is connected to the connection portion 131 via the outer peripheral portion 130.

  Next, the structures of the array substrate 200 and the counter substrate 300 will be described in more detail.

  As shown in FIG. 2, the array substrate 200 is formed using an insulating substrate 210 having light transmissivity such as glass. The switch element 220 is configured by a thin film transistor (TFT) including a semiconductor layer 221 such as an amorphous silicon film or a polycrystalline silicon film. The switch element 220 is covered with an insulating film such as an organic insulating film (hard resin coating) that is the planarizing film 240.

  The pixel electrode 230 is disposed on the planarizing film 240 and is electrically connected to the drain electrode 227 of the switch element 220 through a contact hole formed in an insulating film such as the planarizing film 240. In a transmissive liquid crystal display panel that selectively transmits backlight and displays an image, the pixel electrode 230 transmits light such as indium tin oxide (ITO) or indium zinc oxide (IZO). It is formed of a conductive member having a property. In a reflective liquid crystal display panel that selectively reflects external light and displays an image, the pixel electrode 230 is made of a light-reflective conductive member such as aluminum (Al) or molybdenum (Mo). Is formed.

  The counter substrate 300 is formed using an insulating substrate 310 having optical transparency such as glass.

  In the color display type liquid crystal display device, the liquid crystal display panel 100 displays a plurality of types of pixels, for example, a red pixel PXR that displays red (R), a green pixel PXG that displays green (G), and blue (B). It has a blue pixel PXB.

  In the embodiment shown in FIG. 2, the counter substrate 300 has a color filter layer 320 (R, R, R) arranged on the main surface (front surface) of the insulating substrate 310 for each display pixel PX in the active area 120. G, B). These color filter layers 320 (R, G, and B) are formed of a plurality of colored resins that are colored red (R), green (G), and blue (B), respectively. That is, the counter substrate 300 includes a red color filter layer 320R made of a resin colored so as to transmit light having a red main wavelength corresponding to the red pixel PXR on the insulating substrate 310, and corresponds to the green pixel PXG. And a green color filter layer 320G made of a resin colored so as to transmit light having a green dominant wavelength, and further colored so as to transmit light having a blue dominant wavelength corresponding to the blue pixel PXB. A blue color filter layer 320B made of resin is provided.

  The counter substrate 300 includes a frame-shaped light shielding film 325 arranged so as to surround the active area 120. The light shielding film 325 is made of, for example, a black resin material. The counter electrode 330 is disposed on the color filter layer 320 in the active area 120. The counter electrode 330 is formed of a light-transmissive conductive member such as ITO or IZO.

  The surfaces of the array substrate 200 and the counter substrate 300 are covered with alignment films 250 and 350 for controlling the alignment of the liquid crystal molecules contained in the liquid crystal layer 400, respectively. In addition, on the outer surfaces of the array substrate 200 and the counter substrate 300, a pair of polarizing plates 260 and 360 whose polarization directions are set in accordance with the characteristics of the liquid crystal layer 400 are provided.

  By the way, as shown in FIG. 1, the sealing material 110 is disposed between the array substrate 200 and the counter substrate 300 in a state where an injection port 111 for injecting a liquid crystal material is secured. That is, the sealing material 110 is formed of, for example, a resin material such as a thermosetting resin, and surrounds the active area 120 of one substrate constituting the liquid crystal display panel 100, for example, the array substrate 200 and forms the injection port 111. Applied. Thereafter, in a state where the other substrate, for example, the counter substrate 300 is disposed opposite to the array substrate 200, heating is performed while applying pressure in the direction in which the pair of substrates are bonded to each other. Thereby, the sealing material 110 is cured, and the array substrate 200 and the counter substrate 300 are bonded together. Thereafter, a liquid crystal material is further injected from the injection port 111. Thereafter, as the sealing material 112, for example, a photosensitive resin such as an ultraviolet curable resin is applied to the injection port 111, and the liquid crystal material is sealed by irradiating with ultraviolet rays. Thereby, the liquid crystal layer 400 held between the array substrate 200 and the counter substrate 300 is formed.

  Next, the structure of the inlet 111 and its vicinity will be described in more detail.

  As shown in FIGS. 3 and 4, the liquid crystal display panel 100 includes an active area 120 and a seal portion 115 surrounding the active area 120. The sealing material 110 is disposed on the seal portion 115. The seal part 115 is formed so as to secure the injection port 111.

  The planarization film 240 provided on the array substrate 200 is disposed so as to cover at least the active area 120. A plurality of rows of grooves 242 are formed in the planarization film 240 near the inlet 111. These grooves 242 extend toward the seal portions 115 </ b> A and 115 </ b> B that face each other across the injection port 111. That is, the seal part 115 is formed in a series of loops. Both end portions 115A and 115B of the seal portion 115 are drawn out to the end portion 100E of the liquid crystal display panel 100, and are arranged to face each other with a predetermined interval in order to secure the injection port 111.

  The groove 242 is formed substantially linearly toward both end portions 115A and 115B of the seal portion 115, and is substantially orthogonal to the flow direction of the liquid crystal material injected from the injection port 111. Each of the grooves 242 is disposed substantially in parallel with a predetermined interval.

  With such a configuration, even when a foreign substance is mixed into the liquid crystal material during the injection process of the liquid crystal material, the foreign substance is caught in the groove 242 and the inside of the liquid crystal display panel 100 (that is, on the active area and its surrounding wiring). ) Can be suppressed. Moreover, such a configuration can prevent the sealing material 112 from entering the liquid crystal display panel 100 more than necessary when the sealing material 112 is applied to the injection port 111.

  On the other hand, the sealing material 110 disposed in the seal portion 115 spreads when the array substrate 200 and the counter substrate 300 are pressurized. At this time, the sealing material 110 tends to flow into a narrow gap region between the array substrate 200 and the counter substrate 300 due to a capillary phenomenon. In the example shown in FIG. 4, the sealing material 110 tends to spread along the gap formed by the planarization film 240 and the light shielding film 325.

  Therefore, in this embodiment, a blocking pattern 140 that prevents the seal material 110 from spreading along the inner edge 115IN of the seal portion 115 that defines the inlet 111 is provided. The blocking pattern 140 is disposed at least between the grooves 242.

  By providing such a blocking pattern 140, it is possible to suppress the spread of the sealing material 110 that reduces the injection port 111 in the liquid crystal material injection process. In addition, poor injection of the liquid crystal material and variation in injection time due to the reduction of the injection port 111 are suppressed, and the quality and manufacturing yield of the liquid crystal display panel 100 can be improved.

  Next, a specific configuration example of the blocking pattern 140 described above will be described.

(Configuration example 1)
As shown in FIGS. 5 and 6, the blocking pattern 140 according to Configuration Example 1 is a groove pattern formed in the planarization film 240. That is, the blocking pattern 140 having such a shape is disposed along the inner edge 115IN of the seal portion 115 so as to connect the adjacent grooves 242 at the inlet 111.

  For this reason, in the vicinity of the injection port 111, the gap between the blocking pattern 140 and the counter substrate 300 is widened compared to the gap between the planarization film 240 on the array substrate 200 side and the counter substrate 300, thereby causing a capillary phenomenon. It is possible to suppress the spread of the sealing material 110 to the inlet 111 side.

  According to such configuration example 1, it is possible to prevent the injection port 111 from being reduced due to the spread of the sealing material 110, and it is possible to solve problems such as poor injection of liquid crystal material and variations in injection time. . Therefore, it is possible to provide a liquid crystal display device with good quality without causing a decrease in manufacturing yield.

(Configuration example 2)
As shown in FIG. 7, the blocking pattern 140 according to Configuration Example 2 is a protrusion pattern. That is, the blocking pattern 140 having such a shape is disposed along the inner edge 115IN of the seal portion 115 so as to connect the adjacent grooves 242 at the inlet 111.

  The blocking pattern 140 may be sandwiched between the array substrate 200 and the counter substrate 300 facing the array substrate 200. That is, in the example shown in FIG. 8A, the blocking pattern 140 is in contact with the planarization film 240 on the array substrate 200 side and the light shielding film 325 on the counter substrate 300 side. For this reason, it becomes possible to reliably prevent the seal material 110 from spreading toward the injection port 111 in the vicinity of the injection port 111.

  Further, the blocking pattern 140 may be disposed so as to form a gap between the array substrate 200 and the counter substrate 300. That is, in the example shown in FIG. 8B, the blocking pattern 140 is disposed on the light shielding film 325 on the counter substrate 300 side, and a gap G is formed between the blocking pattern 140 and the planarizing film 240 on the counter substrate 300 side. . For this reason, a narrow gap region between the blocking pattern 140 and the substrate opposed thereto is formed in the vicinity of the injection port 111, and the sealing material 110 spreading toward the injection port 111 can be retained in this narrow gap region by capillary action. It becomes possible.

  According to such configuration example 2, it is possible to prevent the injection port 111 from being reduced due to the spread of the sealing material 110, and it is possible to solve problems such as poor injection of liquid crystal material and variations in injection time. . Therefore, it is possible to provide a liquid crystal display device with good quality without causing a decrease in manufacturing yield.

  In the configuration in which the color filter layer 320 is provided on the same substrate together with the blocking pattern 140, the blocking pattern 140 may be formed of the same material as the color filter layer 320. In the example shown in FIGS. 8A and 8B, the counter substrate 300 includes a blocking pattern 140 and a color filter layer 320 (R, G, B). In the second configuration example, the blocking pattern 140 may be formed using at least one of the color filter layers 320 (R, G, B).

  Further, when the array substrate 200 adopts a color filter on array (COA) structure including a color filter layer 320 (R, G, B) arranged for each pixel PX in the active area 120, a blocking pattern is used. 140 may be provided on the array substrate 200 side.

  Such a blocking pattern 140 is not limited to the color filter layer 320 (R, G, B), and may be formed using other insulating layers. When the blocking pattern 140 is formed using an insulating layer other than the color filter layer, the blocking pattern 140 and the color filter layer 320 (R, G, B) are not necessarily provided on the same substrate.

  In this manner, by forming the blocking pattern using the insulating layer including the color filter layer, a separate process for forming the blocking pattern 140 is not necessary, and an increase in manufacturing cost can be suppressed.

  The blocking pattern 140 may be formed by laminating a plurality of colored resins. According to such a configuration, the gap between the blocking pattern 140 and the opposing substrate can be adjusted by the height of the blocking pattern 140.

(Configuration example 3)
As shown in FIG. 9, the blocking pattern 140 according to the configuration example 3 is a protrusion pattern that is continuous along the inner edge 115IN of the seal portion 115 at the injection port 111. As shown in FIG. 8A, the blocking pattern 140 may be sandwiched between the array substrate 200 and the counter substrate 300 facing the array substrate 200. Alternatively, the blocking pattern 140 faces the array substrate 200 as shown in FIG. 8B. You may arrange | position so that a gap may be formed between the board | substrates 300. FIG.

  According to the configuration example 3 as described above, the injection port 111 can be prevented from being reduced due to the spread of the sealing material 110, and problems such as poor injection of liquid crystal material and variations in injection time can be solved. . Therefore, it is possible to provide a liquid crystal display device with good quality without causing a decrease in manufacturing yield.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the gist of the invention in the stage of implementation. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine the component covering different embodiment suitably.

FIG. 1 schematically shows a configuration of a liquid crystal display panel of a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the configuration of the liquid crystal display panel shown in FIG. FIG. 3 is a plan view schematically showing the structure of the inlet and the vicinity thereof in the liquid crystal display panel shown in FIG. FIG. 4 is a cross-sectional view schematically showing a structure in which the liquid crystal display panel shown in FIG. 3 is cut along line AA. FIG. 5 is a plan view schematically showing the structure of the blocking pattern according to Configuration Example 1. FIG. FIG. 6 is a cross-sectional view schematically showing a structure in which the liquid crystal display panel shown in FIG. 5 is cut along line BB. FIG. 7 is a plan view schematically showing the structure of the blocking pattern according to Configuration Example 2. FIG. 8A is a cross-sectional view schematically showing a structure in which the liquid crystal display panel shown in FIG. 7 is cut along line CC. FIG. 8B is a cross-sectional view schematically showing another structure in which the liquid crystal display panel shown in FIG. 7 is cut along line CC. FIG. 9 is a plan view schematically showing the structure of the blocking pattern according to Configuration Example 3.

Explanation of symbols

PX ... Display pixel Y ... Scan line X ... Signal line 100 ... Liquid crystal display panel 100E ... End part 110 ... Sealing material 111 ... Injection port 112 ... Sealing material 115 ... Sealing part 115IN ... Inner edge 120 ... Active area 130 ... Outer peripheral part 140 ... Blocking pattern 200 ... Array substrate 210 ... Insulating substrate 220 ... Switch element 230 ... Pixel electrode 240 ... Planeization film 242 ... Groove 260 ... Polarizing plate 300 ... Counter substrate 310 ... Insulating substrate 320 (R, G, B) ... Color filter Layer 325 ... Light shielding film 330 ... Counter electrode 400 ... Liquid crystal layer

Claims (8)

Comprising an active area composed of a plurality of display pixels,
A first substrate comprising: a planarizing film disposed on the substrate; and a pixel electrode disposed on each of the display pixels on the planarizing film;
A second substrate having a counter electrode facing each of the pixel electrodes;
A sealing material that secures an injection port for injecting a liquid crystal material and is disposed in a seal portion that surrounds the active area, and bonds the first substrate and the second substrate;
A liquid crystal layer made of a liquid crystal material held between the first substrate and the second substrate,
In the planarizing film, a plurality of rows of grooves extending toward the seal portion facing each other across the injection port are formed,
The liquid crystal display device further comprises a blocking pattern that is disposed at least between the grooves along the inner edge of the seal portion that defines the injection port and prevents the seal material from spreading.   The liquid crystal display device according to claim 1, wherein the blocking pattern is a groove pattern formed in the planarizing film.   The liquid crystal display device according to claim 1, wherein the blocking pattern is a protrusion pattern.   The liquid crystal display device according to claim 3, wherein the protrusion pattern is sandwiched between the first substrate and the second substrate.   The liquid crystal display device according to claim 3, wherein the protrusion pattern is disposed so as to form a gap between the first substrate and the second substrate. The first substrate or the second substrate includes the protrusion pattern, and further includes a color filter layer disposed for each pixel in the active area,
The liquid crystal display device according to claim 3, wherein the protrusion pattern is formed of the same material as the color filter layer. The color filter layer is composed of a plurality of colored resins,
The liquid crystal display device according to claim 6, wherein the protrusion pattern is formed by laminating a plurality of colored resins.   The liquid crystal display device according to claim 1, wherein the blocking pattern is a protrusion pattern that is continuous along an inner edge of the seal portion.

Images