JP2007094039A - Method for manufacturing liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device with successful display quality by preventing poor degassing in manufacturing processes and making thickness of a liquid crystal panel even. <P>SOLUTION: This method for manufacturing the liquid crystal display device has processes of: forming a first mother board M1 having first and second display areas 61B, 61E; forming a second mother board M2 arranged opposite to the first mother board M1 via a space in which liquid crystal compound is filled in the respective display areas; drawing first and second sealants 15B, 15E so as to form a filling port 16 for filling the liquid crystal compound in the space in the surroundings of each the first and second display areas 61B, 61E; drawing a dummy sealant 17 opposite to the filling port formed by the second sealant 15E and extended to the edge of the first mother board M1 between the first sealant 15B and the second sealant 15E and sticking the first mother board M1 and the second mother board M2 via the first and second sealants 15B, 15E. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly to a method for manufacturing a liquid crystal display device manufactured by cleaving a mother substrate.

  The liquid crystal display device has a liquid crystal display panel. The liquid crystal display panel includes a pair of substrates arranged opposite to each other, that is, an array substrate and a counter substrate, and a liquid crystal layer held as a light modulation layer between the pair of substrates. The liquid crystal display panel includes a substantially rectangular display unit that displays an image. This display unit is composed of a plurality of display pixels arranged in a matrix.

  As a method of manufacturing the above liquid crystal display panel, a plurality of liquid crystal display panels are formed from a mother panel in which a first mother substrate that cuts out an array substrate and a second mother substrate that cuts out a counter substrate are formed and bonded together with a sealing material. There is a way to cut out.

Conventionally, as a method for manufacturing a liquid crystal display panel as described above, a dummy seal pattern is formed in a region other than the liquid crystal display panel, and the liquid crystal display device is made uniform by preventing the peeling of the seal during the manufacturing process and making the cell gap uniform. A method has been proposed (see Patent Document 1).
JP-A-10-123539

  However, when a sealing material is drawn on one mother substrate so as to form an injection port for injecting the liquid crystal composition, and the other mother substrate is bonded, the space in the space surrounded by the sealing material It is difficult for air to escape from the inlet, and in particular, it is difficult to secure an air vent path from the inlet located at a position away from the end of the mother substrate to the end of the mother substrate. This is due to the fact that the gap between the mother substrates is locally reduced along the way when the air escape path becomes longer. If the sealing material is cured in a state where the gap between the mother substrates is not uniform, the gap may be different between the cut out liquid crystal display panels.

  In particular, in a liquid crystal display device adopting an optically compensated birefringence method (hereinafter referred to as an OCB method) that requires precise control of the gap, such gap unevenness causes a reduction in display quality.

  The present invention has been made in view of the above-described problems, and prevents liquid from coming out of air in the manufacturing process of a liquid crystal display device and makes the liquid crystal display panel uniform in thickness, thereby providing a liquid crystal display with good display quality. An object is to provide an apparatus.

  A method of manufacturing a liquid crystal display device according to an aspect of the present invention includes a step of forming a first mother substrate having a first display region and a second display region, and a space in which a liquid crystal composition is injected in each display region. A step of forming a second mother substrate disposed opposite to the first mother substrate, and a note for injecting a liquid crystal composition into the space around each of the first display region and the second display region. Drawing the first sealing material and the second sealing material so as to form an inlet, and the inlet formed by the second sealing material between the first sealing material and the second sealing material A step of drawing a dummy sealant facing the first and extending to an end of the first mother substrate, and a step of bonding the first mother substrate and the second mother substrate through the first and second sealants Have

  According to the present invention, it is possible to provide a liquid crystal display device with good display quality by preventing air bleeding failure in the manufacturing process of the liquid crystal display device and making the thickness of the liquid crystal display panel uniform.

  Hereinafter, a liquid crystal display device and a manufacturing method thereof 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 according to an embodiment of the present invention includes a liquid crystal display panel 1 having a substantially rectangular flat plate shape. The liquid crystal display panel 1 is a liquid crystal display panel adopting, for example, an OCB method.

  As shown in FIG. 2, it is constituted by a pair of substrates arranged opposite to each other, that is, an array substrate 3 and a counter substrate 4, and a liquid crystal layer 5 held as a light modulation layer between the pair of substrates. . The liquid crystal display panel 1 includes a substantially rectangular display unit 6 that displays an image. The display unit 6 includes a plurality of display pixels PX arranged in a matrix.

  The array substrate 3 has a display area 61 that constitutes a part of the display unit 6. The display area 61 extends along wirings, for example, a plurality of scanning lines Y (1, 2, 3,..., M) extending along the row direction of the display pixels PX and the column direction of the display pixels PX. A plurality of signal lines X (1, 2, 3,..., N) are provided. The array substrate 3 is connected to the switching elements 7 and 7 arranged for each display pixel PX in the vicinity of the intersection of the scanning line Y and the signal line X in the display region 61 in addition to these various wirings. Pixel electrode 8 and the like.

  The switching element 7 is composed of, for example, a thin film transistor (TFT). The gate electrode of the switching element 7 is electrically connected to the corresponding scanning line Y (or formed integrally with the scanning line). The source electrode of the switching element 7 is electrically connected to the corresponding signal line X (or formed integrally with the signal line). The drain electrode of the switching element 7 is electrically connected to the pixel electrode 8 of the corresponding display pixel PX. The surface of the pixel electrode 8 is covered with an alignment film 16A.

  The array substrate 3 includes a first region 3A facing the counter substrate 4 and a second region 3B extending outward from the end 4E of the counter substrate 4. The first area 3 </ b> A is an area including the display area 61. The second region 3B is a region to which the drive circuit 11 that drives the scanning line Y and the signal line X can be connected.

  The counter substrate 4 is opposed to the first region 3 </ b> A of the array substrate 3. The counter substrate 4 includes a counter display region 62 that constitutes a part of the display unit 6 and faces the display region 61 of the array substrate 3. The counter display area 62 includes a counter electrode 9 and the like common to all the display pixels PX. The counter electrode 9 is formed of a light-transmitting conductive member such as indium tin oxide (ITO). The surface of the counter electrode 9 is covered with an alignment film 16B.

  The array substrate 3 and the counter substrate 4 are arranged in a state where the alignment film 16A on the pixel electrode 8 and the alignment film 16B on the counter electrode 9 face each other, and a liquid crystal composition that becomes the liquid crystal layer 5 is interposed therebetween. It is bonded together by a sealing material 15 through a space for injection. The sealing material 15 forms an injection port 16 for injecting the liquid crystal composition into the space between the array substrate 3 and the counter substrate 4, and is disposed around the display unit 6. That is, the sealing material 15 is disposed so as to surround a space into which the liquid crystal composition is injected. The liquid crystal composition injected from the inlet 16 is sealed with a sealing material 18.

  The liquid crystal display panel 1 of the color display type liquid crystal display device has a plurality of types of display pixels, for example, a red pixel that displays red, a green pixel that displays green, and a blue pixel that displays blue. That is, the red pixel includes a red color filter 12R that transmits light having a red main wavelength. The green pixel includes a green color filter 12G that transmits light having a green dominant wavelength. The blue pixel includes a blue color filter 12B that transmits light having a blue main wavelength. The color filter layer 12 composed of these color filters 12R, 12G, and 12B is disposed on the main surface of the counter substrate 4 on the liquid crystal layer 5 side.

  A light shielding layer 13 is formed between the color filters 12R, 12G, and 12B (that is, between display pixels) and around the counter display area 62. The light shielding layer 13 formed between the color filters 12R, 12G, and 12B is disposed so as to face the signal lines X and the scanning lines Y on the array substrate 3. For example, the light shielding layer 13 is formed of a colored resin colored black.

  Next, a method for manufacturing the liquid crystal display panel 1 will be described. In the present embodiment, a method for manufacturing a mother panel M that cuts out a plurality of, for example, twelve liquid crystal display panels 1 (A to L) will be described. The mother panel M includes a first mother substrate M1 that cuts out the array substrate 3 (A to L) and a second mother substrate M2 that cuts out the counter substrate 4 (A to L).

  First, a method for manufacturing the first mother substrate M1 and the second mother substrate M2 will be described. First, an insulating substrate having optical transparency is prepared. On this insulating substrate, a metal film or an insulating film is repeatedly formed and patterned, and various wirings such as signal lines X and scanning lines Y, switching elements 7, pixel electrodes 8, alignment films 16A, and the like are provided. A first mother substrate M1 including the display areas 61 (A to L) is formed.

  On the other hand, the second mother substrate M2 having the light shielding layer 13, the color filter layer 12, the counter electrode 9, the alignment film 16B, and the like is formed by repeating the formation and patterning of a metal film or a colored resin film on another insulating substrate. Form.

  Subsequently, the sealing material 15 (A to L) for bonding the first mother substrate M1 and the first mother substrate M2 is drawn. In this embodiment, the sealing material 15 (A to L) is drawn on the first mother substrate M1. The sealing material 15 (A to L) is arranged around each display region 61 (A to L) and forms an injection port 16 (A to L) for injecting a liquid crystal composition to be the liquid crystal layer 5. To do.

  Furthermore, a dummy seal material 17 is drawn which extends to the end of the first mother substrate M1 so as to face the injection port formed at a position away from the end of the first mother substrate M1. In the case shown in FIG. 3, it faces the injection ports 16 (E, H, K) and the injection ports 16 (D, G, J) far from the end of the first mother substrate M1, and the first mother substrate M1 Three dummy seal members 17 extending to the end are drawn.

  For example, in this embodiment, the first display area 61B and the second display area 61E are formed on the first mother substrate M1. A first sealing material 15B is formed around the first display area 61B. A second sealing material 15E is formed around the second display area 61E. The second sealing material 15E forms an injection port 16E for injecting the liquid crystal composition at a position facing the first sealing material 15B.

  At this time, the dummy sealing material 17 facing the injection port 16E is between the first sealing material 15B arranged around the first display area 61B and the sealing material 15E arranged around the second display area 61E. And extending to the end of the first mother substrate M1.

  Subsequently, the first mother substrate M1 and the second mother substrate M2 are arranged so that the display areas 61 (A to L) and the counter display areas 62 (A to L) face each other, and the liquid crystal composition is enclosed. These are pasted together by the sealing material 15 (A to L) and the dummy sealing material 17 in a state where a space to be formed is formed. At this time, a vacuum press is performed in order to bond the first mother substrate M1 and the second mother substrate M2.

  Since the dummy sealing material 17 is disposed as described above during the decompression pressing step, the first mother substrate M1 and the first mother substrate M1 are formed between the inlet formed near the center of the mother substrate and the end of the mother substrate. A gap with the second mother substrate M2 is secured. In other words, the air in the space surrounded by the sealing material 15 (D, E, G, H, J, K) between the first mother substrate M1 and the second mother substrate M2 by the dummy sealing material 17 becomes the end of the substrate. It is possible to secure a route R that is pushed out.

  Subsequently, the sealing material 15 and the dummy sealing material 17 are cured. Thereby, a mother panel is formed. Thereafter, the mother panel M bonded with the first mother substrate M1 and the second mother substrate M2 is cleaved along the cleaving line CL, and a liquid crystal composition is injected and sealed from each injection port 16 (A to L). Through the process of stopping, etc., twelve liquid crystal display panels 1 (A to L) are manufactured.

  According to the liquid crystal display panel 1 (A to L) manufactured as described above, the liquid crystal display panel 1 in which the injection port 16 is formed at a position away from the end of the mother substrate, particularly the liquid crystal display panel shown in FIG. By securing the air vent path R of 1 (E, H, K), air vent failure in the manufacturing process of the liquid crystal display panel 1 (A to L) is prevented. Thus, the thicknesses of all the liquid crystal display panels 1 (A to L) cut out from the same mother panel can be made substantially uniform.

  Next, a specific structural example of the dummy sealing material 17 will be described. As shown in FIG. 3, the first structure example is an example in which at least one dummy seal material 17 is arranged between adjacent seal materials (for example, seal materials 15A and 15D), and is shown in FIG. Thus, the diameter D1 of the dummy seal material 17 arranged between the seal material 15A and the seal material 15D is formed larger than the diameter D2 of the seal material 15A and the seal material 15D.

  Here, the diameter of the sealing material corresponds to the height of the sealing material corresponding to the thickness direction of the mother panel. The dummy sealing material having such a structure can be formed, for example, by drawing slower than the drawing speed of the sealing material 15 (A to L) in the step of drawing the dummy sealing material.

  According to the first structure example, when the first mother substrate M1 and the second mother substrate M2 are bonded together, the diameter D1 of the dummy seal material 17 is larger than the diameter D2 of the seal material 15, The gap between the first mother board M1 and the second mother board M2 is not easily crushed, and the first mother board M1 and the second mother board M2 are surrounded by the sealing material 15 (D, E, G, H, J, K). It is possible to secure a path R for pushing out air in the space to the end of the substrate.

  Next, a second structure example of the dummy seal material 17 will be described. As shown in FIG. 5, the second structure example is an example in which a plurality of, for example, two dummy seal members 17 are arranged between adjacent seal members (for example, the seal members 15A and 15D).

  A manufacturing method of the liquid crystal display device to which the dummy sealing material 17 of the second structure example is applied is as follows. That is, in the step of drawing the dummy seal material 17 on the first mother substrate M1, the first dummy seal material 17A and the second dummy seal material 17B extending substantially parallel to each other are drawn.

  In the case shown in FIG. 5, it faces the injection port 16 (E, H, K) and the injection port 16 (D, G, J) far from the end of the first mother substrate M1, and the first mother substrate M1 Three dummy seal members 17 extending to the end portions are drawn.

  For example, in the step of drawing the dummy seal material 17 facing the injection port 16E, the seal material 15B disposed around the first display region 61B and the seal material 15E disposed around the second display region 61E. The first dummy sealing material 17A and the second dummy sealing material 17B which are arranged between the two and extend to the end portion of the first mother substrate M1 are drawn.

  When the first mother substrate M1 and the second mother substrate M2 are bonded together through the dummy sealing material and the sealing material formed in this way, from the inlet formed near the center of the mother substrate to the end of the mother substrate As shown in FIG. 6, a gap between the first mother substrate M1 and the second mother substrate M2 is secured by the first dummy sealing material 17A and the second dummy sealing material 17B.

  That is, the first dummy sealing material 17A and the second dummy sealing material 17B are surrounded by the sealing material 15 (D, E, G, H, J, K) between the first mother substrate M1 and the second mother substrate M2. It is possible to secure a path R through which air in the space is pushed out to the end of the substrate.

  The manufacturing method of the liquid crystal display panel to which the dummy sealing material 17 of the second structural example is applied is the same as the manufacturing method of the liquid crystal display panel 1 (A to L) except for the process of drawing the dummy sealing material 17 described above. is there. According to the second structure example, as in the first structure example, the liquid crystal display panel 1 (E, H, K) in which the injection port is formed at a position apart from the end portion of the first mother substrate M1 is manufactured. Air venting failure in the process is prevented, and the thickness of the liquid crystal display panel 1 (A to L) can be made uniform.

  A manufacturing method of the liquid crystal display device to which the dummy sealing material 17 of the third structure example is applied is as follows. That is, in the step of drawing the dummy sealing material 17 on the first mother substrate M1, the dummy sealing material 17 including the fiber 19B having a larger diameter than the fiber 19A included in the sealing material 15 (A to L) is drawn.

  For example, in the case illustrated in FIG. 3, the first mother substrate is opposed to the injection ports 16 (E, H, K) and the injection ports 16 (D, G, J) that are separated from the end portion of the first mother substrate M1. Three dummy seal members 17 extending to the end of M1 are drawn.

  When the first mother substrate M1 and the second mother substrate M2 are bonded together through the dummy seal material 17 and the seal material 15 formed in this way, the end of the mother substrate is formed from the injection port formed near the center of the mother substrate. As shown in FIG. 7, the gap between the first mother substrate M1 and the second mother substrate M2 is secured by the dummy sealing material 17 between the first mother substrate M2 and the second mother substrate M2.

  That is, the dummy sealing material 17 includes a fiber 19B having a larger diameter than the fiber 19A included in the sealing material 15. Therefore, the air in the space surrounded by the sealing material 15 (D, E, G, H, J, K) between the first mother substrate M1 and the second mother substrate M2 is removed from the end of the substrate by the dummy sealing material 17. It is possible to secure a route R that is pushed out.

  The manufacturing method of the liquid crystal display panel to which the dummy sealing material 17 of the third structural example is applied is the same as the manufacturing method of the liquid crystal display panel 1 (A to L) described above except for the process of drawing the dummy sealing material 17 described above. is there. According to the third structure example, similarly to the first and second structure examples, the liquid crystal display panel 1 (E, H, K) in which the injection port is formed at a position apart from the end portion of the first mother substrate M1. ) In the manufacturing process is prevented, and the thickness of the liquid crystal display panel 1 (A to L) can be made uniform.

  As described above, according to the present invention, the air in the space surrounded by the sealing material 15 is pushed out to the end portion of the substrate between the first mother substrate M1 and the second mother substrate M2 by the dummy sealing material 17. Therefore, the air venting failure of the liquid crystal display panel that occurs in the manufacturing process of the liquid crystal display device can be prevented. In particular, for the liquid crystal display panel 1 in which the injection port is formed at a position away from the end of the mother substrate, it is possible to prevent air bleeding defects in the manufacturing process, so that the thickness of the liquid crystal display panel is made uniform and the display quality is improved. A liquid crystal display device with good quality can be provided.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage.

  In the above embodiment, the substantially linear dummy sealing material 17 is drawn on the first mother board M1, but the dummy sealing material 17 may be curved, and is formed of a plurality of islands arranged continuously. There may be. Also in this case, the same effect as the above embodiment can be obtained.

  In the above embodiment, the sealing material 15 and the dummy sealing material 17 are drawn on the first mother substrate M1, but may be drawn on the second mother substrate M2. Also in this case, similarly to the above-described embodiment, the first mother substrate M1 and the second mother substrate M2 are bonded together and cleaved to each liquid crystal display panel, thereby preventing the air bleeding failure of the liquid crystal display panel. The same effect as that of the embodiment can be obtained.

  In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

1 is a diagram schematically showing a liquid crystal display panel of a liquid crystal display device according to one embodiment of the present invention. The figure which shows an example of the cross section which cut | disconnected the liquid crystal display panel shown in FIG. 1 by line AA. The figure explaining the example of the manufacturing method of the 1st mother board | substrate used as the array board | substrate of the liquid crystal display device which concerns on 1st and 3rd embodiment of this invention. The figure which shows an example of the cross section which cut | disconnected the panel which bonded the 1st mother board | substrate and the 2nd mother board | substrate by the line BB shown in FIG. The figure explaining the example of a manufacturing method of the 1st mother board | substrate used as the array board | substrate of the liquid crystal display device which concerns on 2nd Embodiment of this invention. The figure which shows an example of the cross section which cut | disconnected the panel which bonded the 1st mother board | substrate and the 2nd mother board | substrate by the line CC shown in FIG. The figure which shows an example of the cross section which cut | disconnected the panel which bonded the 1st mother board | substrate and the 2nd mother board | substrate by the line BB shown in FIG.

Explanation of symbols

  PX ... display pixel, Y ... scanning line, X ... signal line, M1 ... first mother substrate, M2 ... second mother substrate, R ... air venting path, 1 (AL) ... liquid crystal display panel, 3 (A- L) ... array substrate, 4 (A to L) ... counter substrate, 5 ... liquid crystal layer, 6 ... display unit, 15 (A to L) ... sealing material, 16 (A to L) ... inlet, 17 ... dummy seal Material, 17A ... 1st dummy sealing material, 17B ... 2nd dummy sealing material, 61 (AL) ... Display area, 62 (AL) ... Opposite display area

Claims (3)

Forming a first mother substrate having a first display area and a second display area;
Forming a second mother substrate disposed opposite to the first mother substrate through a space into which the liquid crystal composition is injected in each display region;
Drawing a first sealing material and a second sealing material so as to form an inlet for injecting a liquid crystal composition into the space around each of the first display region and the second display region; ,
Drawing a dummy seal material between the first seal material and the second seal material, facing the injection port formed by the second seal material and extending to an end of the first mother substrate;
And a step of bonding the first mother substrate and the second mother substrate through the first and second sealing materials.   The method of manufacturing a liquid crystal display device according to claim 1, wherein a speed at which the dummy sealing material is drawn is slower than a speed at which the sealing material is drawn.   The method of manufacturing a liquid crystal display device according to claim 1, wherein the step of drawing the dummy seal material includes a step of drawing a first dummy seal material and a second dummy seal material that extend substantially parallel to each other.

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