JP2009237032A - Liquid crystal display panel and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display panel capable of preventing display quality from getting worse, and to provide a method for manufacturing the same. <P>SOLUTION: The liquid crystal display panel with a liquid crystal LC sandwiched between the first substrate 10 and the second substrate 11 includes a frame-like partitioning wall 13 formed to surround a display area 12, and a seal pattern 14 for bonding the first substrate 10 and the second substrate 11 and formed to surround the display area 12 from an outside of the partitioning wall 13, wherein the liquid crystal is filled between the seal pattern 14 and the partitioning wall 13. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal display panel in which liquid crystal is sandwiched between a first substrate and a second substrate, and a method for manufacturing the same.

  In a method for manufacturing a liquid crystal display panel, a liquid crystal material is injected between a pair of substrates to form a liquid crystal display panel. After bonding the pair of substrates, a vacuum is applied between the pair of substrates, and a predetermined liquid crystal injection port A vacuum injection method in which liquid crystal material is injected between a pair of substrates by generating suction force and capillary action from between the substrates by immersing the liquid crystal in the liquid crystal, and dropping the liquid crystal material on one substrate in a vacuum Further, there is a dropping injection method in which the other substrate is overlaid and bonded so as to cover the other substrate.

  In the dropping injection method, a pattern is formed with a sealant made of a photocurable resin so as to surround a region where a liquid crystal layer is formed on one of a pair of substrates, and then surrounded by the pattern of the sealant. A liquid crystal material is dropped in a vacuum in the region, bonded to the other substrate, and the sealant is cured by irradiating the sealant with light.

  However, in the dripping injection method, the liquid crystal comes into contact with the uncured sealant or the irradiation light is blocked by a light shielding film or the like, and the sealant is likely to be insufficiently cured. There is a possibility that the contained component may be dissolved in the liquid crystal and display defects such as display unevenness may occur.

Therefore, in order to prevent contact between the sealing agent and the liquid crystal, a technique has been proposed in which a partition that separates the sealing agent and the liquid crystal layer is provided between the sealing agent and the display region filled with the liquid crystal (Patent Document 1). ).
JP 2008-26566 A

  However, in the dropping injection method, a liquid crystal material is dropped onto one substrate in a vacuum, and the other substrate is overlaid and bonded so as to cover the other substrate. Therefore, in the case where a space is generated between the sealing agent and the partition wall, the region surrounded by the sealing agent and the partition wall is maintained in a vacuum state. When the sealing property of the partition wall is broken, the liquid crystal sealed in the display area by the partition wall leaks into the area surrounded by the sealant and the partition wall, and the total amount of liquid crystal in the display area is reduced. There has been a problem in that the cell quality in the region is reduced and the display quality is lowered.

  In view of the above-described conventional drawbacks, the present invention is to provide a liquid crystal display panel and a method for manufacturing the same that can prevent deterioration in display quality.

  In order to achieve the above object, a liquid crystal display panel according to claim 1 is a liquid crystal display panel in which liquid crystal is sandwiched between a first substrate and a second substrate so as to surround a display region. And a seal pattern formed to surround the display area from the outside of the partition wall, the frame-shaped partition wall formed, and the first substrate and the second substrate are bonded. A liquid crystal is filled between the pattern and the partition wall.

  The liquid crystal display panel according to claim 2 is the liquid crystal display panel according to claim 1, wherein an interval between the first substrate and the second substrate is set in the display region of the first substrate. A spacer that is held constant is formed, and the partition is made of the same material as the spacer.

  The liquid crystal display panel according to claim 3 is the liquid crystal display panel according to claim 1 or 2, wherein the seal pattern is cured after liquid crystal is filled between the seal pattern and the partition wall. It is characterized by being.

  A liquid crystal display panel according to claim 4 is the liquid crystal display panel according to any one of claims 1 to 3, wherein the partition wall and the seal pattern are formed of different materials. .

  The method for producing a liquid crystal display panel according to claim 5 is a method for producing a liquid crystal display panel in which a liquid crystal is sandwiched between a first substrate and a second substrate, and on the first substrate, A partition forming step of forming a frame-shaped partition so as to surround the display region, and a seal pattern forming step of forming a seal pattern for bonding the first substrate and the second substrate so as to surround the partition; And a liquid crystal dropping step of dropping a liquid crystal between the region surrounded by the partition and the seal pattern and the partition in a reduced pressure atmosphere.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent that the display quality of a liquid crystal display panel falls.

  Hereinafter, embodiments of the liquid crystal display panel 1 of the present invention will be described. As shown in FIGS. 1 and 2, the liquid crystal display panel 1 includes a liquid crystal LC sandwiched between a first substrate 10 and a second substrate 11, and frame-shaped partition walls 13 that surround the display region 12. Is formed. In addition, the first substrate 10 and the second substrate 11 are bonded, and a seal pattern 14 is formed so as to surround the display region 12 from the outside of the partition wall 13. A region 15 surrounded by the partition wall 13 including the display region 12 and a region 16 surrounded by the partition wall 13 and the seal pattern 14 are filled with the liquid crystal LC.

  Specifically, the partition wall 13 is formed in a substantially rectangular frame shape surrounding the entire periphery of the display area 12. If the frame width of the partition wall 13 is, for example, 0.1 mm or more and 1.0 mm or less, the liquid crystal in the region surrounded by the partition wall 13 can be relatively reliably sealed in the region, and the liquid crystal display panel Although it is preferable that the frame as one non-display area can be made relatively narrow, the size of the frame width of the partition wall 13 is not limited to this.

  The seal pattern 14 is formed in a substantially rectangular frame shape that surrounds the entire periphery of the partition wall 13, and each side of the partition wall 13 that is also formed in a substantially rectangular frame shape corresponds to each of the seal patterns 14. The sides are arranged in parallel. And if the frame width of the seal pattern 14 is 0.5 mm or more and 2.0 mm or less, for example, the first substrate 10 and the second substrate 11 can be bonded with relatively high strength, Although the frame as the non-display area of the liquid crystal display panel 1 can be made relatively narrow, it is preferable. However, the size of the frame width of the seal pattern 14 is not limited to this.

  The seal pattern 14 and the liquid crystal LC in the display region 12 are separated without contacting each other through the partition wall 13 therebetween.

  Here, a plurality of display pixels P (i, j) are formed in the display region 12. A pixel transistor TFT as a switching element and a pixel electrode 17 connected to the pixel transistor TFT are formed on the side of the first substrate 10 facing the second substrate 11 so as to correspond to each display pixel. Has been. As shown in FIG. 3, each pixel transistor TFT is also connected to a data signal line S (i) to which a display signal voltage is supplied and a scanning signal line G (j) to which a scanning signal is supplied. Further, a common electrode 18 having the same potential Vc between the display pixels is formed on the surface of the second substrate 11 facing the first substrate 10. In each display pixel, an auxiliary capacitor Ccs for holding a display signal voltage written in each pixel electrode is added to a liquid crystal capacitor Clc composed of a liquid crystal LC sandwiched between the pixel electrode 17 and the common electrode 18. Connected in parallel.

  In addition, the display region 12 avoids the pixel electrode 17 and has a cylindrical shape or a method for keeping the distance between the first substrate 10 and the second substrate 11, that is, the thickness of the liquid crystal layer constant. A spacer 19 having a shape is formed. The spacer 19 does not necessarily have to be formed in each display pixel. For example, the spacer 19 may be formed at a rate of one for several pixels. The distance between the first substrate 10 and the second substrate 11 is approximately 2 μm or more and 10 μm or less.

  By the way, when the liquid crystal display panel 1 is used as a transmissive liquid crystal display device, the first substrate 10 and the second substrate 11 are preferably non-alkali glass or a quartz substrate, but have translucency. If it is a substrate, a flexible material such as a plastic material such as polyimide or polycarbonate can also be used.

  Next, with reference to FIGS. 4A to 4E, a method for manufacturing the liquid crystal display panel 1 will be described. 2A to 2E are schematic cross-sectional views for explaining a method for manufacturing the liquid crystal display panel 1. FIG.

  As shown in FIG. 4A, a second substrate 11 is prepared in which a common electrode 18 made of a transparent conductive film (for example, ITO) is provided at least in a region corresponding to the display region 12. And as shown in FIG.4 (b), in order to hold | maintain the space | interval of the frame-shaped partition 13 surrounding the display area 12 of the 2nd board | substrate 11 and the 1st board | substrate 10 and the 2nd board | substrate 11 uniformly. The spacers 19 are collectively formed.

  Specifically, a partition wall material made of an ultraviolet curable resin such as an acrylic resin is supplied onto the second substrate 11 provided with the common electrode 18 by, for example, a spin coating method. Next, the barrier ribs 13 and the spacers 19 are pattern-formed by, for example, a photolithography method using a predetermined mask pattern. The partition wall 13 is formed in a substantially rectangular frame shape surrounding the entire periphery of the display area 12. Here, the partition wall 13 and the spacer 19 are formed at a height corresponding to a target interval between the first substrate 10 and the second substrate 11, for example, approximately 2 μm or more and 10 μm or less.

  The alignment film (not shown) that defines the initial alignment of the liquid crystal is preferably formed either before or after the partition wall 13 and the spacer 19 are formed.

  Next, as shown in FIG. 4C, a seal pattern 14 including a photocurable resin is formed so as to surround the display region 12 of the second substrate 11 from the outside of the partition wall 13. The seal pattern 14 can be performed by a screen printing method or a drawing method using a dispenser. The seal pattern 14 is cured by irradiating light after the liquid crystal is dropped on the second substrate 11, but the liquid crystal is deteriorated by irradiating the liquid crystal with light. In order to prevent this, it is preferable to use a material that can be cured in the region closer to the visible light than the ultraviolet region.

  Next, an active element composed of the pixel electrode 17, the pixel transistor TFT, the data signal line S (i), the scanning signal line G (j) and the like is formed in the display region 12, and the initial alignment of the liquid crystal is formed on the outermost surface thereof. The first substrate 10 on which an alignment film (not shown) for defining the thickness is formed is prepared, and the pressure is reduced from the atmospheric pressure together with the partition wall 13, the spacer 19, and the second substrate 11 on which the seal pattern 14 is formed. In a reduced pressure atmosphere.

  Then, in a reduced pressure atmosphere, as shown in FIG. 4D, a predetermined amount of liquid crystal LC is dropped on the display region 12 of the second substrate 11 and the region 16 between the seal pattern 14 and the partition wall 13, and then As shown in FIG. 4E, the first substrate 10 and the second substrate 11 are bonded to each other through the seal pattern 14.

  Next, in a state where the first substrate 10 and the second substrate 11 are bonded together, for example, the seal pattern 14 is irradiated with light from the second substrate 11 side through the second substrate 11. Specifically, when a sealant containing an ultraviolet curable resin is used for the seal pattern 14, for example, 100 mW ultraviolet rays are irradiated for 20 seconds to 200 seconds. And it takes out under atmospheric pressure. When the seal pattern 14 further contains a thermosetting resin or a solvent using an ultraviolet curable resin as a solvent, after the light irradiation, for example, 90 ° C. to 150 ° C. in an oven. Therefore, it is preferable to post-bake for 30 minutes to 90 minutes. Post baking may be performed under atmospheric pressure or in a nitrogen atmosphere.

  In the first substrate 10, circuit elements for electrical connection are also formed in the non-display area, which is made of a light-shielding material such as metal, so that the seal pattern 14 can be securely attached. In order to irradiate light, it is preferable to irradiate light from the second substrate 11 side. In addition, when the liquid crystal LC dropped on the display area 12 is irradiated with ultraviolet rays, the liquid crystals may be deteriorated. Therefore, only the seal pattern 14 can be selectively irradiated with ultraviolet rays through a predetermined mask pattern. It is preferable to irradiate with light.

  Since the liquid crystal display panel manufactured in this way is filled with the liquid crystal LC between the seal pattern 14 and the partition wall 13, the sealing performance by the partition wall 13 is broken for some reason after the liquid crystal display panel is manufactured. Even if it is done, the total amount of liquid crystal in the display area 12 will not decrease, and the cell thickness in the display area 12 will not decrease. Therefore, in the liquid crystal display panel in which the liquid crystal LC is also filled between the seal pattern 14 and the partition wall 13, it is possible to prevent the display quality of the liquid crystal display panel from being deteriorated. In addition, since the partition wall 13 and the spacer 19 are formed at the same time in the same process, the partition wall 13 can be formed without increasing the number of processes.

  In the above-described embodiment, the case where the common electrode that is set to the same potential in each display pixel is formed on the second substrate side is described. However, the common electrode that is set to the same potential in each display pixel. Is also applicable when formed on the first substrate side. That is, the present invention can be applied not only to a liquid crystal display panel for a vertical electric field mode liquid crystal display mode but also to a liquid crystal display panel for a horizontal electric field mode liquid crystal display mode.

  In the above-described embodiment, the case where the partition wall 13 and the spacer 19 are formed on the second substrate 11 has been described. However, the partition wall 13 and the spacer 19 may be formed on the first substrate 10. Good.

  In the above-described embodiment, the case where the seal pattern 14 is formed on the second substrate 11 has been described. However, the seal pattern 14 may be formed on the first substrate 10.

  In the above embodiment, the case where the seal pattern 14 is formed on the substrate on which the partition wall 13 and the spacer 19 are formed has been described. However, the seal pattern 14 is formed on the partition wall 13 and the spacer 19. It is good also as a structure formed in the other board | substrate. In this case, the liquid crystal is preferably dropped onto the substrate on the side where the seal pattern 14 is formed.

  Further, in the above-described embodiment, the case where the seal pattern 14 and the partition wall 13 are arranged so as not to contact each other has been described, but the seal pattern 14 and the partition wall 13 are partially in contact with each other. The arrangement may be sufficient. In any case, it is only necessary that the space generated between the seal pattern 14 and the partition wall 13 is filled with liquid crystal.

Schematic plan view of a liquid crystal display panel according to the present invention Schematic sectional configuration diagram of a liquid crystal display panel according to the present invention The figure for demonstrating a display pixel Typical sectional drawing for demonstrating the manufacturing method of the liquid crystal display panel 1

Explanation of symbols

1: liquid crystal display panel 10: first substrate 11: second substrate 12: display region 13: partition 14: seal pattern 17: pixel electrode 18: common electrode 19: spacer LC: liquid crystal

Claims (5)

A liquid crystal display panel in which liquid crystal is sandwiched between a first substrate and a second substrate,
A frame-shaped partition formed so as to surround the display area;
The first substrate and the second substrate are bonded, and the display area is formed so as to surround the display area from the outside of the partition wall, and
A liquid crystal display panel, wherein a liquid crystal is filled between the seal pattern and the partition wall. A spacer is formed in the display area of the first substrate to maintain a constant distance between the first substrate and the second substrate,
The liquid crystal display panel according to claim 1, wherein the partition wall is made of the same material as the spacer.   The liquid crystal display panel according to claim 1, wherein the seal pattern is cured after liquid crystal is filled between the seal pattern and the partition wall.   4. The liquid crystal display panel according to claim 1, wherein the partition wall and the seal pattern are made of different materials. A method of manufacturing a liquid crystal display panel in which liquid crystal is sandwiched between a first substrate and a second substrate,
On the first substrate, a partition forming step for forming a frame-shaped partition so as to surround the display region;
A seal pattern forming step for forming a seal pattern for bonding the first substrate and the second substrate so as to surround the partition;
A method of manufacturing a liquid crystal display panel, comprising: a liquid crystal dropping step of dropping a liquid crystal between the region surrounded by the partition walls and the seal pattern and the partition walls in a reduced pressure atmosphere.

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