JP2001255540A - Method for manufacturing liquid crystal display panel, and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a small cell gap, in a short time. SOLUTION: In the method and device for the manufacturing a liquid crystal panel, by sealing the periphery of a first substrate and a second substrate with an adhesive, while a prescribed gap is left and injecting a liquid crystal, one substrate is pressed gradually from its center to its edge by an air bag against the other substrate to discharge the air between the two substrates to form the cell gap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a liquid crystal display panel.

[0002]

2. Description of the Related Art In a liquid crystal display panel, an alignment film made of polyimide is applied to the surface of two substrates with transparent electrodes, and a rubbing operation is performed. Apply sealing material (adhesive) to the periphery and apply 2
It is made by bonding two substrates and injecting liquid crystal into the gap.
In the method of mechanically applying pressure when two substrates are bonded to each other, the substrates cannot be pressed uniformly over the entire surface because the substrates have uneven thickness. The gap is called a cell gap, but it was difficult to make the cell gap uniform. With an increase in the speed of liquid crystal display, the cell gap has become smaller. At present, it is necessary to manufacture a liquid crystal display panel having a cell gap of 1 μm or less.

When the cell gap becomes small, the display quality deteriorates due to unevenness of the display screen, coloring, or the like, unless two substrates are bonded together in parallel with high accuracy. As a manufacturing method for bonding two substrates in parallel with high precision, two substrates are pressed with an air bag using air pressure as disclosed in Japanese Patent No. 2880686 (Japanese Patent Laid-Open No. 3-73930). And a method of bonding them together has been developed. 1 and 2 are disclosed in Japanese Patent No. 2880686 as a cross-sectional view illustrating a method for manufacturing a liquid crystal display panel and a cross-sectional view illustrating a configuration of the liquid crystal display panel.

The liquid crystal display panel shown in FIG. 2 is manufactured as follows. Alignment films 205 and 206 are formed on a first substrate 201 having a transparent electrode 203 and a second substrate 202 having a transparent electrode 204, respectively.
First substrate 201 and second substrate 202 on which 206 is formed
Is subjected to a rubbing treatment. An epoxy resin is applied on the rubbed first substrate 201 with a sealant (adhesive) 20.
8 and pre-cured at a temperature of 100 ° C. for 10 minutes. On the other hand, plastic beads are dispersed as spacers 207 on the rubbed second substrate 202. The first substrate and the second substrate are aligned and bonded, placed on a jig shown in FIG. 1, baked at a temperature of 160 ° C. for 90 minutes while applying pressure, and curing the sealant 208 to form a sealing step. Complete. Next, liquid crystal is injected.

[0005] The base material 101 of the liquid crystal display panel manufacturing apparatus for curing the sealant is larger than the outer diameter of the first substrate 107 or the second substrate 108 constituting the liquid crystal display panel. At least two columns 120 are provided at positions outside the substrate on the base material 101. An air bag 103 made of a rubber bag is arranged on the base material 101, and the air bag 1
A flat plate 105 serving as a reference is placed on the flat plate
5 are placed on the first substrate 107 and the second substrate 108 described above with reference to FIG. 2, and a thin plate is placed on the first substrate 107 and the second substrate 108. 106 and the airbag 1 same as the airbag 103
04, and a stopper 111 is attached to a portion of the support 120 that penetrates the upper base 102 having a through hole for passing the support 120, and the upper base 102 and the base 101 are formed by the stopper 111 and the support 120. To fix the base material 101, the airbag 103, the flat plate 105, the liquid crystal display panel, the thin plate 106, the airbag 102, and the upper base material 102.

After that, compressed air is injected into the airbags 103 and 104, and pressure is applied to the two substrates 107 and 108 bonded together. Air pressure is usually 0.5 kg / cm ²
To 1.0 kg / cm ² . Also, if firing is performed at a temperature of 160 ° C. during curing of the epoxy resin, the air in the air bag expands, and the air bag 103, 10
Since the pressure inside 4 rises, a regulator is installed outside to adjust it to a constant pressure. In this method, the first substrate 107 and the second substrate
Since the sealing material 109 is hardened following the reference flat plate 105, the two bonded substrates after firing are flat surfaces, and do not cause any problem in the subsequent steps.

[0007] Since the pressure of air is used, if the size of the two bonded substrates is, for example, 30 cm square, a total of 450 kg to 900 kg of force can be easily applied. When such pressure is applied, the base plate 101 is naturally warped. However, since the reference flat plate 105 is provided, the bonded first substrate 107 and second substrate 108 serving as products do not warp. . Further, since pressure is applied to the first substrate 107 and the second substrate 108 via the thin plate 106, pressure can be uniformly applied to the first substrate 107 and the second substrate 108, It is possible to correct warpage and undulation between the substrate 107 and the second substrate 108 and follow uneven thickness.

[0008]

The above-described apparatus for manufacturing a liquid crystal display panel can correct the warpage and undulation of the substrate and follow the uneven thickness. However, in order to press the entire surface of the substrate, the apparatus has a thickness of 1 μm or less. Forming a small gap has the following problems.

A spacer member for determining a gap is mixed in an adhesive material (sealant, sealing material) applied to the periphery of the substrate, and has a thickness of 2 to 3 μm when applied. When the two substrates are overlapped with an adhesive and the entire substrate is pressed flat, an air layer is formed between the two substrates for the thickness of the adhesive, which is provided for injecting liquid crystal later. The cell gap cannot be reduced unless air escapes from the inlet. Pressing must be continued for 60 seconds or more in order to push out the air in the air layer and reduce the cell gap to 1 μm or less.

Since the liquid crystal injection port is small and the adhesive is not cured, the shape of the injection port collapses if air is discharged from the injection port at a high speed without a pre-curing step.
This may cause variation in the subsequent process.

[0011]

In a method for manufacturing a liquid crystal display panel in which the periphery of a first substrate and a periphery of a second substrate are provided with a predetermined gap and sealed with an adhesive, a liquid crystal is injected. A method of manufacturing a liquid crystal display panel in which a cell gap is formed by gradually pressing the other substrate from the center of the substrate to the peripheral edge of the substrate to release air between the two substrates.

In a liquid crystal display panel manufacturing apparatus in which the periphery of the first substrate and the periphery of the second substrate are provided with a predetermined gap and sealed with an adhesive, the other substrate is gradually moved from the center of one substrate to the periphery by an air bag. To evacuate the air between the two substrates to form a cell gap.

[0013] A liquid crystal display panel manufacturing apparatus is provided in which a deflection is provided at a central portion of a surface of the airbag that contacts the substrate.

[0014]

FIG. 3 is a sectional view of an apparatus for manufacturing a liquid crystal display panel according to the present invention. A UV curable adhesive is used as a sealant for the liquid crystal display panel. The base member 301 of the apparatus for manufacturing a liquid crystal display panel is configured to be larger than the outer diameter of the first substrate 307 or the second substrate 308 that constitutes the liquid crystal display panel. At least two columns 305 are provided on the base material 301 outside the substrate. The first substrate 307 and the second substrate 308 bonded together as described with reference to FIG. 2 are placed on the base material 301, and the base material 3 is placed on the first substrate 307.
02, an airbag sheet 303 (a sheet, which is an airbag in cooperation with the base member 302) made of an elastic material such as rubber, which is hermetically fixed by a stopper plate 304, is arranged at a predetermined interval. The base member 302 includes a plurality of columns 3
05. A pipe 306 for supplying compressed air is fixed above the base member 302.

Thereafter, compressed air is injected into the airbag, and pressure is applied to the two substrates 307 and 308 bonded together.
In this method, the airbag sheet 303 expands, and the first substrate 307 is pressed against the second substrate 308 via a sealant and a spacer or a sealant. The airbag sheet 303 expands with compressed air, but expands in a hemispherical shape so that the surface area is minimized.
The first substrate 307 from the center of the airbag sheet 303;
Start pressurizing. If the center of the airbag sheet 303 and the center of the first substrate 307 are aligned, a portion of the first substrate 307 that is initially pressurized and then pressurized so that ripples gradually spread. Spreads to the periphery. In addition, if the center of the airbag sheet 303 is processed so as to be easily swelled, or if a bend is provided, the center of the airbag sheet can reliably start pressing the center of the substrate first.

First, the central portion of the first substrate 307 hits a spacer (not shown), gradually spreads to the periphery, and finally, the sealing agent portion is pressurized to form a cell gap. , Air escape between the cell gaps is improved, and a predetermined cell gap can be formed in a short time. FIG. 4 shows an airbag 303 and the first substrate 30.
7A is a cross-sectional view showing a change in a state of pressing the airbag sheet 7, and FIG. 7A is a state diagram in which the airbag sheet 303 starts to press the center of the first substrate 307, and FIG.
03 is a state diagram in which the entire surface of the first substrate 307 is pressed.

The above is a description of the case where one large liquid crystal display panel is manufactured. Hereinafter, an example in which the present invention is applied to a case where a plurality of small liquid crystal display panels are manufactured at the same time will be described. FIG. 5 is a top view of a substrate in which a plurality of liquid crystal display panel patterns are formed on one substrate. A large number of liquid crystal display panel portions are formed on one substrate 501 (first substrate), and a sealant 502 is applied. The first substrate 501 and a second substrate (not shown) are bonded together via a sealant 502, and then divided into individual liquid crystal display panels.

In order to form a large number of liquid crystal display panel portions on a large first substrate 501, the liquid crystal display panel portions are arranged in a grid pattern, a second substrate is bonded, and then scribed with a diamond wheel or the like for division. This is a well-known mass production technique when the liquid crystal display panel is small. Although the amount of the sealant 502 applied on the substrate is large, it is required that all the sealants be uniformly pressurized. Even in such a structure, it is possible to easily and quickly apply a uniform pressure by applying the present invention.

By starting pressing from the center of the substrate and sequentially expanding the pressing surface toward the outer edge, air passes through the space between the sealing agents 502 formed in a grid pattern from the center of the substrate. Since it is extruded toward the outer edge, no air pockets remain between the substrates, and the sealant can be quickly and uniformly pressed.

[0020]

According to the present invention, the air between the two substrates is evacuated quickly (2 to 3 seconds) by gradually pressing the substrate from the center of one substrate to the peripheral edge of the substrate with the other substrate to release the air between the two substrates.
The two substrates (sealant and spacer) can be pressed uniformly, and as a result, a uniform air gap can be quickly formed.

By bending the central portion of the surface of the airbag that contacts the substrate, the contact of the airbag with the substrate can be reliably started from the central portion of the airbag.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a method of manufacturing a liquid crystal display panel according to the related art.

FIG. 2 is a cross-sectional view showing a configuration of a liquid crystal display panel according to the related art.

FIG. 3 is a cross-sectional view of the liquid crystal display panel manufacturing apparatus of the present invention.

4A is a cross-sectional view showing a change in a state in which an airbag 303 presses a substrate 307. FIG. 4A is a state diagram in which an airbag sheet 303 starts pressing a substrate 307.
(B) is a state diagram in which the airbag sheet 303 presses the entire surface of the substrate 307.

FIG. 5 is a top view of a substrate in which a plurality of patterns for a liquid crystal display panel are formed on one substrate.

[Explanation of symbols]

 101 base material 102 base material 103 air bag 104 air bag 105 flat plate 106 thin plate 107 first substrate 108 second substrate 109 sealant 111 stopper 120 support 201 first substrate 202 second substrate 203 transparent electrode 204 transparent electrode 205 Alignment film 206 Alignment film 207 Spacer 208 Sealant 301 Base material 302 Base material 303 Airbag sheet 304 Stop plate 305 Support 306 Piping 307 First substrate 308 Second substrate 501 First substrate 502 Sealant

Claims (3)

[Claims] 1. A method of manufacturing a liquid crystal display panel in which a predetermined gap is provided around a periphery of a first substrate and a second substrate with an adhesive, and liquid crystal is injected. A method of manufacturing the liquid crystal display panel, wherein the cell gap is formed by gradually pressing the other substrate to the other substrate to release air between the two substrates. 2. A liquid crystal display panel manufacturing apparatus in which the peripheral edges of a first substrate and a second substrate are provided with a predetermined gap and sealed with an adhesive. A manufacturing method for a liquid crystal display panel, wherein air is removed between two substrates by pressing against the substrate to form a cell gap. 3. The liquid crystal display panel manufacturing apparatus according to claim 2, wherein a center portion of a surface of the airbag that contacts the substrate is bent.