JP2002214620A - Method of manufacturing plane display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time for regulation and to improve the productivity of a plane display element in which the spacing is held by spacer columns by smoothing the alignment regulation of two substrates facing each other in forming the display cells of the plane display element. SOLUTION: An aligner head 32 of an aligner 30 is moved by driving thrust force 150 kgf, thereby, the roughly aligned and bonded color filters substrate 11 and array substrate 12 are made smoothly slidable and movable with each other and the time for the alignment regulation is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a flat panel display device, and more particularly to a method for manufacturing a flat panel display device in which two opposing substrates are smoothly aligned.

[0002]

2. Description of the Related Art Liquid crystal or electro-optical devices are used in portable OA equipment, computer terminals, and image display devices such as televisions. In a flat display element having a light modulation layer such as luminescence, a spacer is provided to keep a gap between a pair of substrates forming a display cell constant.

[0003] In recent years, in place of the spherical spacers which are randomly scattered in the display area of any one of the above-mentioned substrates, the unevenness of the display due to the skew of the scatter is caused, and in recent years, the display has been improved. In order to obtain a high-quality display image, a flat display element is widely used in which a gap between a pair of substrates is kept constant by spacer columns formed by patterning a photoresist or the like on the substrates.

On the other hand, when assembling a display cell, a pair of substrates are conventionally roughly aligned by a plane mounter, opposed to each other, pressed by a required pressure, and bonded together, and an aligner is used to reduce a pattern shift between the two substrates. After the alignment adjustment, the sealant was cured.

[0005]

However, if the above-mentioned spacer pillars are integrally formed on a substrate, and they are bonded by a plane mounter at the time of assembling the display cell, the two substrates come into close contact with each other. It was not possible to slide smoothly, and it took a long time to adjust the alignment until the target alignment accuracy was reached. This is because when a conventional spherical spacer is used as a spacer, alignment is easily adjusted by an aligner because there is little friction when moving the substrates, but when a spacer column is used as a spacer between the two substrates. It has been found that the frictional force generated between the spacer pillar and the opposing substrate is large. For this reason, especially when the arrangement density of the spacer pillars is high, the frictional force between the spacer pillars and the opposing substrate is further increased, so that the time for alignment adjustment is significantly increased, and the problem that the productivity is remarkably reduced occurs. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been developed in order to improve the display quality by using spacer pillars integrally formed on at least one substrate. After the two substrates to be bonded are pressed and bonded via the spacer pillar, when adjusting the alignment of the pattern shift of the pixel pitch,
It is an object of the present invention to provide a method of manufacturing a flat display element, which can smoothly slide both substrates against each other against a frictional force generated between the two substrates to reduce alignment time and improve productivity.

[0007]

According to the present invention, in order to solve the above-mentioned problems, a spacer pillar is formed on at least one of the substrates at an arrangement density of one or less for every two pixels, and the opposing substrate is formed by the spacer pillar. In a method for manufacturing a flat display element, two substrates holding a gap between the spacer pillars are adhered with a sealant, and a light modulation layer is sealed in a region surrounded by the sealant. A bonding step in which the two substrates are pressed against each other, and after the bonding step, the two substrates are relatively slid with a driving propulsion force of 130 kgf or more to align the two substrates. And a bonding step of curing the sealant after the completion of the positioning step.

With this configuration, the present invention allows the two substrates to smoothly move each other by applying a sufficient driving propulsion force between the two substrates to oppose the frictional force caused by the contact between the spacer pillar and the opposing substrate. Since the slide can be moved, the alignment adjustment time is shortened to improve the productivity.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the following results were obtained by conducting a measurement test of the time required for alignment adjustment between a color filter substrate of a display cell in which a gap is maintained by using a spacer column and an array substrate. Was. For example, both substrates of a display cell in which spacer columns having a contact area of 7 × 12 μm are arranged at a ratio of one for every three pixels are adjusted to 100 kgf by an aligner.
When the positioning is attempted with the driving propulsion force, the two substrates cannot slide smoothly with each other because the frictional force between the two substrates is strong.
When the time is 0 sec or more, it takes a long time for alignment adjustment. Therefore, using the same display cell and gradually increasing the driving propulsion force of the aligner, if the driving propulsion force of the aligner is set to 130 kgf or more, regardless of the frictional force between the two substrates, The array substrate can be slid smoothly with each other, and approximately 30 to 50 seconds and a driving propulsion force of 100 k are required to obtain predetermined alignment accuracy.
It has been found that the alignment adjustment can be remarkably shortened as compared with gf. This also means that regardless of the size of the display cell,
It has been found that similar results can be obtained.

On the other hand, when the arrangement density of the spacer columns of the liquid crystal cell was increased to increase the frictional force between the two substrates, it was found that even if the arrangement density of the spacer columns was one for every two pixels, the aligner was driven. Propulsion force is 130 kgf or more, preferably 150 kgf
If f or more, the color filter substrate and the array substrate can be smoothly slid relative to each other in the same manner as described above. Note that even if the driving propulsion force of the aligner exceeds 500 kgf, the effect is not improved. Therefore, the driving propulsion force of the aligner of 500 kgf or less is sufficient.

Therefore, the present invention has been made based on the above test results.

Hereinafter, the present invention will be described with reference to the embodiment shown in FIGS. FIG. 1 shows a liquid crystal display device 1 which is a light transmission type flat display device of XGA specification with a diagonal of 15 inches.
FIG. 2 is a structural view showing a liquid crystal layer 14 serving as a light modulation layer in a gap formed by bonding the periphery with a sealant 15 of a color filter substrate 11 and an array substrate 12 which are arranged to face each other via a spacer pillar 13. are doing.

The color filter substrate 11 is, for example,
Glass substrate 1 for forming a 5 inch effective display area
6, a black matrix (hereinafter abbreviated as BM) 17a made of an acrylic resin, R (red), G (green), and B
The color filter layer 17 in which the (blue) colored layers 17b are arranged in a stripe pattern and indium tin oxide (hereinafter referred to as I)
Called TO. )).
Further, the color filter substrate 11 has a spacer pillar 1 made of acrylic resin at a position on the counter electrode 18 and overlapping with the BM.
3 are arranged in three pixels at one arrangement density, and a liquid crystal alignment film 23 is formed thereon. The gap between the color filter substrate 11 and the array substrate 12 is maintained at about 5 μm by the spacer pillar 13.

On the other hand, the array substrate 12 has a thin film transistor element (not shown) near an intersection of a gate line 21 and a signal line (not shown) on a glass substrate 20 for forming a 15-inch diagonal effective display area. And the gate line 21
Further, in a region surrounded by signal lines (not shown), a pixel electrode 22 which is patterned in a matrix and is connected to a thin film transistor element is provided, and a liquid crystal alignment film 24 is formed thereon. Further, the liquid crystal display element 10 includes a polarizing plate 26 outside the color filter substrate 11 and the array substrate 12.
27.

On the other hand, the aligner 30 for aligning the pixel pitches of the color filter substrate 11 and the array substrate 12 has:
A stage 31 for placing and adsorbing and fixing the color filter substrate 11 and the array substrate 12 which are roughly aligned and adhered by pressure, and X, Y,
And an aligner head 32 movable in the three-dimensional Z direction. The aligner head 32 includes a suction pad 33 that suction-holds the surfaces of both substrates 11 and 12 placed on the stage 31.

Next, a method for manufacturing the liquid crystal display element 10 will be described. First, patterning by a normal photolithography process is repeated on the glass substrate 14 to obtain R (red),
The color layers 17b of G (green) and B (blue) are sequentially patterned in stripes, and the BM 17a is further patterned to obtain the color filter layer 17. Next, after forming an ITO film by a sputtering method, a pattern is formed by a photolithography process, and the counter electrode 1 is formed on the color filter layer 17.
8 are formed, and further, a spacer 13 is patterned, and then a liquid crystal alignment film 23 is applied thereon.
Get 1.

Next, patterning by a normal photolithography process is repeated on the glass substrate 20 to form a wiring layer such as the gate line 21 and a thin film transistor element.
Next, I is formed by sputtering through an oxide insulating film (not shown).
After the TO film is formed, a pattern is formed by a photolithography process, and pixel electrodes 22 arranged in a matrix in a region surrounded by gate lines 21 and signal lines (not shown) are formed, and then a liquid crystal alignment film 24 is applied. Thus, an array substrate 12 is obtained. Further, the liquid crystal alignment films 23 and 24 are each subjected to alignment treatment by rubbing.

Subsequently, the color filter substrate 11 is washed,
A sealant 15 mixed with, for example, a thermosetting epoxy resin is applied to the periphery of the display area so as to surround the display area by providing an injection port (not shown). Thereafter, the color filter substrate 11 and the array substrate 1 are moved by a plane mounter (not shown).
The color filter substrate 11 and the array substrate 12 are bonded to each other through the spacer pillars 13 by roughly positioning the substrates 2 facing each other and applying pressure by an air press (not shown).

After that, the color filter substrate 1 bonded thereto
1 and the array substrate 12 as shown in FIG.
Is placed on the stage 31. Further, after lowering the alignment head 32 and sucking the surface of the color filter substrate 11 with the suction pad 33, the alignment head 32 is horizontally moved with a driving propulsion force of 150 kgf to
1 and the array substrate 12 are slid with respect to each other, and alignment is adjusted until the pattern shift of the pixel pitch reaches a predetermined alignment accuracy. At this time, the number of alignment adjustments by the aligner was 5 to 10 times, and the required time was about 30 to 50 seconds.

Thereafter, the sealant 15 is heated and cured, and the color filter substrate 11 and the array substrate 12 are adhered with the sealant 15 to obtain the liquid crystal cell 10b. Next, a liquid crystal composition is injected into a gap between the liquid crystal cells 10b held by the spacer columns 13 from an injection port (not shown) formed in the sealant 15, and the injection port is further sealed with an ultraviolet curing resin (not shown). After stopping and enclosing the liquid crystal layer 14, the color filter substrate 1
The liquid crystal display device 10 is completed by attaching the polarizing plates 23 and 24 to the array substrate 1 and the array substrate 12, respectively.

With such a configuration, the color filter substrate 11 and the array substrate 12 mounted on the aligner after the bonding by contact are moved at a driving propulsion force of 150 kgf, thereby reducing the frictional force between the substrates 11 and 12. In contrast, the two substrates 11 and 12 can be smoothly slid relative to each other with a larger driving propulsion force, so that the time required for alignment adjustment can be significantly reduced, and the productivity of the liquid crystal display element 10 which maintains the gap by using the spacer pillar can be improved. Improvements can be obtained, and mass production and cost reduction can be achieved.

It should be noted that the present invention is not limited to the above-described embodiment, but can be changed without departing from the spirit of the present invention. For example, the arrangement density of the spacer columns for holding the gap between the flat display elements is two pixels. If the number is one or less, the drive propulsion force of the aligner may be 130 kgf or more.
Further, the size of the flat display element is not limited. Further, the flat display element is not limited to the liquid crystal display element, and may be an element for displaying an image using another light modulation layer, or a spacer column may be provided on the array substrate side. Also, when manufacturing display cells, a plurality of display cells may be manufactured simultaneously by a multi manufacturing method for forming a plurality of flat display element patterns on a glass substrate.

[0023]

As described above, according to the present invention, at the time of manufacturing a flat display element in which a gap is maintained by a spacer column, two substrates disposed opposite to each other are made larger against the frictional force caused by contact. Since the two members can be moved smoothly by the driving propulsion force, the alignment adjustment is easy, and the adjustment time can be remarkably reduced. As a result, mass production and cost reduction can be achieved by improving the productivity of the flat display element.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a liquid crystal display element according to an embodiment of the present invention.

FIG. 2 is a schematic explanatory view showing an aligner according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display element 11 ... Color filter substrate 12 ... Array substrate 13 ... Spacer pillar 14 ... Liquid crystal layer 15 ... Sealant 16 ... Glass substrate 17 ... Color filter layer 18 ... Counter electrode 20 ... Glass substrate 21 ... Gate line 22 ... Pixel Electrode 30 ... Aligner 31 ... Stage 32 ... Aligner head 33 ... Suction pad

Claims (5)

[Claims] 1. A spacer column is formed on at least one of the substrates at an arrangement density of one pixel or less for every two pixels, and two substrates that maintain a gap with an opposing substrate by the spacer columns are sealed with a sealant. In a method for manufacturing a flat display element, wherein a light modulation layer is sealed in a region surrounded by the sealant, the spacer column is bonded to an opposing substrate by applying pressure. After the process is completed, the two substrates are
a positioning step of positioning the two substrates by sliding relative to each other with a driving propulsion force of gf or more, and an attaching step of curing the sealant after the completion of the positioning step. A method for manufacturing a flat panel display device, comprising: 2. The method according to claim 1, wherein the two substrates are a color filter substrate having a color filter layer and a counter electrode, and an array substrate having a plurality of pixel electrodes and a driving element for driving the pixel electrodes. The method according to claim 1, wherein, in the step, the position of the color filter layer is aligned with the plurality of pixel electrodes. 3. The method according to claim 1, wherein a driving propulsion force for sliding the two substrates relative to each other is 150 kgf or more. 4. The method according to claim 1, wherein the spacer columns are formed at an arrangement density of one for every three pixels. 5. The method according to claim 1, wherein the light modulating layer is a liquid crystal layer made of a liquid crystal composition.