JP2008076893A - Manufacturing method of display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent spacer particles from being left in a pixel region after a droplet vaporizes when the spacer particles are disposed on a substrate by injecting the droplet containing the spacer particles. <P>SOLUTION: A manufacturing method of a display device includes the stages of: injecting the droplet 15 of liquid prepared by mixing spacer particles 7 with at least one of ethylene glycol, propylene glycol, and diethylene glycol and a diluted solution having lower viscosity than it toward between a pixel electrode 9 and a pixel electrode 9 on an array substrate; putting the array substrate 4 where the injected droplet 15 sticks in a drying furnace for drying; and sticking an opposite substrate 5 on the array substrate 4 with the spacer particles 7 interposed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a display device, and more particularly, to a method for manufacturing a display device in which spacer particles are arranged between an array substrate and a counter substrate in order to keep the distance between the array substrate and the counter substrate constant.

  In a manufacturing method of a liquid crystal display device in which spacer particles and a liquid crystal are interposed between a pair of translucent substrates, as described in Patent Document 1, droplets containing the spacer particles are inkjet printed. A method is known in which spraying is performed on one translucent substrate using an apparatus, and spacer particles are arranged on the one translucent substrate. The spacer particles are members used to maintain the distance between the pair of translucent substrates uniformly over the entire area of the translucent substrate.

By ejecting droplets containing spacer particles using an inkjet printing apparatus, the spacer particles are targeted at a target area, for example, a boundary area between the pixel area and the pixel area on a translucent substrate. It becomes possible to arrange.
JP-A-57-57124

  However, in the method for manufacturing the display device described above, the following points are not considered.

  As the pixel density of the display device is increased, the distance between the pixel region is reduced. Therefore, when a droplet containing spacer particles is ejected toward the boundary region between the pixel region and the pixel region, the diameter of the ejected droplet is the boundary region between the pixel region and the pixel region. It becomes larger and some of the droplets enter the pixel area.

  For this reason, when the droplets evaporate and the spacer particles contained in the droplets remain, a situation occurs in which the spacer particles remain in the pixel region.

  When the spacer particles and the liquid crystal are interposed between the pair of translucent substrates, the liquid crystal is not present at the position where the spacer particles exist between the pair of translucent substrates. Is left in the pixel region, the portion where the spacer particles remain is always a bright spot, and the quality of the image displayed by the display device is lowered.

  The present invention has been made to solve such a problem. The purpose of the present invention is to eject droplets containing spacer particles and to disperse the droplets when the spacer particles are arranged on the substrate. It is an object of the present invention to provide a method for manufacturing a display device capable of preventing spacer particles from remaining in a pixel region later.

  A first feature according to an embodiment of the present invention is that, in the method for manufacturing a display device, spacer particles are mixed with at least one of ethylene glycol, propylene glycol, and diethylene glycol and a diluted liquid having a lower viscosity. Ejecting liquid droplets between the pixel electrodes on the array substrate and between the pixel electrodes, placing the array substrate with the ejected droplets in a drying furnace, and drying the array And attaching a counter substrate to the substrate with the spacer particles interposed therebetween.

  According to the present invention, when the droplets containing the spacer particles are ejected onto the array substrate, and the spacer particles remain on the array substrate after the droplets evaporate, the spacer particles remain in the pixel region. It can be prevented from remaining on the surface.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a liquid crystal display device 1 as a display device includes a transmissive liquid crystal display panel 2 and a drive circuit board (not shown) for supplying a drive signal to the liquid crystal display panel 2 as shown in FIG. And a backlight 3 that illuminates the liquid crystal display panel 2 from the back side. The liquid crystal display panel 2 and the drive circuit board are electrically connected via a flexible wiring board or the like.

  In the liquid crystal display panel 2, an array substrate 4, a counter substrate 5 disposed to face the array substrate 4, and a liquid crystal 6 and spacer particles 7 are disposed between the array substrate 4 and the counter substrate 5. The periphery of the array substrate 4 and the counter substrate 5 is sealed by a sealing member (not shown), and leakage of the liquid crystal 6 is prevented.

  The array substrate 4 includes an insulating substrate 8 having optical transparency such as a glass substrate, a plurality of scanning lines, a plurality of signal lines, a plurality of switching elements, and a plurality of pixel electrodes 9 formed on the insulating substrate 8. And. The pixel electrodes 9 are formed of a light transmissive conductive member, arranged in an m × n matrix, and the upper part of each pixel electrode 9 is an individual pixel region.

  The counter substrate 5 includes an insulating substrate 10 having a light transmission property such as a glass substrate, and a counter electrode 11 formed on the insulating substrate 10. The counter electrode 11 is formed of a light transmissive conductive member, and is disposed to face all the pixel electrodes 9.

  The spacer particles 7 are formed into a ball shape from transparent glass or resin. The spacer particles 7 are disposed between the array substrate 4 and the counter substrate 5, and maintain a constant interval between the array substrate 4 and the counter substrate 5. In addition, the spacer particles 7 are arranged in a boundary area between the pixel area on the array substrate 4.

  A manufacturing process of the liquid crystal display device 1 will be described with reference to FIG. First, the array substrate 4 in which the pixel electrodes 9 and the like are formed on the insulating substrate 8 is prepared. Further, a liquid in which at least one of ethylene glycol, propylene glycol, and diethylene glycol is mixed with a diluted liquid (for example, water) having a lower viscosity is generated, and the spacer particles 7 are mixed in the liquid.

  The liquid in which the spacer particles 7 are mixed is filled in an ink jet printing apparatus (not shown), and this liquid is ejected between the pixel electrodes 9 on the array substrate 4 between the pixel electrodes 9 and FIG. As shown in a), the ejected droplets 12 are deposited on the array substrate 4. The diameter of the droplet 12 is, for example, several tens of μm, which is larger than the interval between the pixel electrode 9 and the pixel electrode 9 (for example, 18 μm), and a part of the droplet 12 is placed on the pixel electrode 9. Become. In addition, the ejected droplet 12 includes the spacer particles 7, and it is uncertain where the spacer particles 7 are located in the droplet 12. For example, the spacer particles 7 may be placed on the pixel electrode 9.

  Next, the array substrate 4 to which the ejected droplets 12 are attached is placed in a drying furnace (not shown) and dried. In this drying step, the droplets 12 are gradually evaporated and the diameter of the droplets 12 is gradually reduced. In this case, the diluted liquid having a lower viscosity than ethylene glycol, propylene glycol, or diethylene glycol evaporates faster, and the higher viscosity ethylene glycol, propylene glycol, diethylene glycol, or the like evaporates later. The droplets 12 whose diameter is reduced by evaporation of the low-viscosity dilution medium has a high ratio of ethylene glycol, propylene glycol, diethylene glycol, or the like having high viscosity. For this reason, as the diameter of the droplet 12 decreases, the spacer particles 7 contained in the droplet 12 are attracted toward the center of the droplet 12 as shown in FIG.

  When the droplet 12 evaporates and disappears, as shown in FIG. 2C, the spacer particles 7 are attracted to the central position of the droplet 12, and the spacer particles 7 are attracted to the pixel electrode 9. It is located in a position that does not rest on.

  After the drying process is completed, the counter substrate 5 is attached to the array substrate 4 after the drying process with the spacer particles 7 interposed therebetween.

  After the array substrate 4 and the counter substrate 5 are pasted, the liquid crystal 6 is filled between the array substrate 4 and the counter substrate 5, and after the liquid crystal 6 is filled, the periphery of the array substrate 4 and the counter substrate 5 is sealed. The liquid crystal display panel 2 is manufactured by sealing with.

  After the liquid crystal display panel 2 is manufactured, the liquid crystal display device 1 is completed by assembling the liquid crystal display panel 2 and the backlight 3 in a housing (not shown).

  In such a configuration, when the spacer particles 7 are arranged on the array substrate 4, the liquid in which the spacer particles 7 are mixed is applied to the pixel electrode 9 and the pixel electrode 9 on the array substrate 4 by an inkjet printing apparatus. The droplets 12 are ejected in the middle to adhere to the array substrate 4, and the droplets 12 are evaporated to leave only the spacer particles 7 on the array substrate 4. And the liquid which mixes this spacer particle | grains 7 is produced | generated by mixing at least one of ethylene glycol, propylene glycol, and diethylene glycol, and a dilution liquid (for example, water) with a viscosity lower than it. For this reason, in the process in which the droplet 12 evaporates and the diameter is reduced, the dilute liquid with low viscosity evaporates quickly, and ethylene glycol, propylene glycol, diethylene glycol, etc. with high viscosity evaporate later. For this reason, the droplet 12 whose diameter has been reduced by evaporation of the low viscosity dilution medium has a higher ratio of ethylene glycol, propylene glycol, diethylene glycol or the like having a higher viscosity. The spacer particles 7 included in the liquid 12 are attracted toward the center of the droplet 12.

  Therefore, when the droplet 12 evaporates and disappears, as shown in FIG. 2C, the spacer particles 7 are attracted to the center position of the droplet 12, and the spacer particles 7 are attracted to the pixel electrode 9. And the pixel electrode 9.

  As a result, the spacer particles 7 can be positioned outside the pixel region, and the spacer particles 7 exist in the pixel region, and the location where the spacer particles 7 are present is always displayed as a bright spot. It is possible to prevent the quality of the image to be reduced from being deteriorated.

It is a vertical side view which shows the liquid crystal display device of one embodiment of this invention. It is a top view which shows a part of manufacturing process of a liquid crystal display device.

Explanation of symbols

  4 ... Array substrate, 5 ... Counter substrate, 7 ... Spacer particle, 9 ... Pixel electrode, 15 ... Droplet

Claims (1)

A droplet of liquid in which spacer particles are mixed with at least one of ethylene glycol, propylene glycol, and diethylene glycol and a diluted liquid having a lower viscosity is ejected between the pixel electrodes on the array substrate. A process of
Putting the array substrate to which the ejected droplets are attached into a drying furnace and drying;
Attaching the counter substrate to the array substrate with the spacer particles interposed therebetween;
A method for manufacturing a display device, comprising:

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