JP2002303871A - Manufacturing method and manufacturing apparatus for liquid crystal display device - Google Patents

Abstract

(57) [Problem] To provide a manufacturing method of a liquid crystal display device for manufacturing a high-precision and high-quality liquid crystal display device by a manufacturing process with a short tact time, and a manufacturing device thereof. SOLUTION: Protruding means 19 for bending a central portion of an upper substrate 6 forming a liquid crystal cell toward a lower substrate 1 by a predetermined amount is provided.

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 liquid crystal display device in which two glass substrates which have been subjected to a predetermined treatment are bonded with a sealing agent with high precision in a vacuum atmosphere to form a liquid crystal cell. It relates to the manufacturing apparatus.

[0002]

2. Description of the Related Art In general, a liquid crystal display device comprises a liquid crystal cell formed by applying a sealant around two opposing substrates, such as glass, around an opposing inner surface and providing a gap to adhere to the substrate. The liquid crystal is injected into the gap between the substrates and sealed.
Injection of liquid crystal is often performed by suction injection or drop injection.

[0003] The suction type injection is a method in which liquid crystal is injected from an injection port provided in a cell in advance by utilizing a capillary phenomenon or the like, and therefore requires a long tact time. On the other hand, drop injection using a drop head such as a dispenser has the merit of greatly shortening the tact time. Therefore, in recent years, the demand for large liquid crystal cells such as liquid crystal TVs has been increasing. It is particularly suited and attracts attention.

The production of a liquid crystal cell into which liquid crystal is injected by drop injection is performed, for example, by a liquid crystal cell manufacturing apparatus whose schematic configuration is shown in FIG. FIG. 6 is a top view of the glass substrate at that time.

The liquid crystal cell manufacturing apparatus is provided with a lower stage 53 on which a lower substrate 52 made of glass is mounted on a base 51. Above the lower stage 53, the lower stage 53 is opposed to the lower substrate 52 and has a predetermined shape. The XYZθ moving mechanism 56 is provided with an upper stage 55 for holding the upper substrate 54 made of glass with the positional accuracy described above. The XYZθ moving mechanism 56 is fixed to a portal gantry 57 provided on the base 51. In addition, the portal frame 5
A cover 58 is provided outside the base 7 and covers the entire upper part of the base 51 to form a vacuum chamber connected to a vacuum pump (not shown). A through hole 59 is formed in the center of the lower stage 53, and a recognition camera 61 and a UV irradiating unit 62 are arranged at positions communicating with the through hole 59 of the base 51.

A UV-curable sealant 63 is applied on the lower substrate 52 in a closed loop, and a liquid crystal 64 is dropped inside the UV-curable sealant 63 by a dispenser (not shown). In addition, both substrates 52 and 54 are provided with identification marks 65a and 65b for alignment, respectively.

As shown in FIGS. 7 (a) and 7 (b), the bonding operation of the liquid crystal cell manufacturing apparatus having the above-described structure is performed by firstly attaching the lower substrate 52 to the lower stage 53 and the upper stage 55. The upper substrates 54 are respectively fixed. The vacuum pump is operated to bring the inside of the vacuum chamber into a vacuum atmosphere (a). In this state, the XYZθ moving mechanism 56 is operated. At that time, both the substrates 52,
The upper substrate 54 and the lower substrate 52 are brought closer to each other while observing the recognition marks 65 a and 65 b provided on the lower substrate 54 and relatively positioned, and the UV-curable sealant 63 applied to the lower substrate 52 is applied. Through the contact. Then UV
The UV curable sealant 63 is irradiated with UV light by the irradiation means 62 to fix the two substrates 52 and 54 (b). As a result, the liquid crystal 64 dropped inside the UV curable sealant 63 is spread to a uniform thickness and sealed. Thereby, a liquid crystal cell is completed. In this case, both substrates 5
Since the bonding of 2 and 54 is performed in a vacuum atmosphere, no bubbles enter the liquid crystal 64.

[0008]

However, in the above-mentioned bonding step, accurate substrate holding means in a vacuum is indispensable in order to bond and position two glass substrates in a vacuum atmosphere.

As shown in FIG. 8, the conventional substrate holding method employs a suction stage 82 having a large number of holes or grooves 81a, 81b. The mainstream method is to evacuate the substrate 52 by vacuuming means (not shown) and hold the substrates 52 and 54 by suction. However, this method has a drawback that when the degree of vacuum increases, a sufficient pressure difference cannot be obtained between the degree of vacuum in the chamber and the degree of vacuum in the suction system, so that the upper substrate 54 cannot be particularly gripped.

The present invention has been made based on these circumstances, and provides a method and apparatus for manufacturing a liquid crystal display device for manufacturing a liquid crystal display device with high accuracy and high quality by a manufacturing process with a short tact time. It is intended to be.

[0011]

According to the first aspect of the present invention, a step of mounting a first substrate on a lower stage, a step of holding a second substrate on an upper stage, Applying a sealant for sealing to at least one of the first and second substrates, applying a liquid crystal to a predetermined position of the first substrate, disposing the first and second substrates to face each other, Performing relative positioning based on the alignment marks provided on the first and second substrates, and projecting at least one of the first and second substrates toward the other opposing substrate, and bringing the first and second substrates close to a predetermined gap. A method for manufacturing a liquid crystal display device, comprising: a step of bonding both substrates in a vacuum atmosphere via the sealant.

According to the second aspect of the present invention,
A lower stage for holding a first substrate, an upper stage for holding a second substrate, a moving unit for relatively moving the first and second substrates, and at least one of the first and second substrates; A sealant applying means for applying a sealant for sealing on one side, a position recognizing means for recognizing respective substrate positions from alignment marks provided on the first and second substrates, and the position recognizing means. Control means for driving the moving means based on the respective substrate positions recognized by the means to align the first and second substrates, and at least one of the aligned first and second substrates. An apparatus for manufacturing a liquid crystal display device, comprising a projecting means for projecting a part of one substrate toward the other substrate.

According to the third aspect of the present invention,
The apparatus for manufacturing a liquid crystal display device, wherein the holding means for the second substrate provided on the upper stage is a claw mechanism for supporting a part of the outer periphery of the second substrate.

According to the fourth aspect of the present invention,
An apparatus for manufacturing a liquid crystal display device, further comprising a liquid crystal applying means for applying a liquid crystal to a predetermined position of the first substrate.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

First, the outline of the manufacturing process of the liquid crystal cell will be described with reference to the manufacturing process diagram of the liquid crystal cell shown in FIG. The array substrate on which the pixel electrodes and the like to be the lower substrate (first substrate) 1 are formed in the bonding step is annealed (S1). Thereafter, a UV-curable sealant 3 is applied to the surface of the lower substrate 1 by a dispenser (seal applying means) 2 in a rectangular closed loop according to the size of the screen (S2). Next, the liquid crystal 4 which has been previously defoamed is dropped into the square shape by a dropping head (liquid crystal coating means) 5 (S
3). The surface of the lower substrate 1 is coated with a UV-curable sealing agent (not shown) for temporary fixing on a line connecting recognition marks (alignment marks) of the substrate described later.

On the other hand, the substrate on which the color filter, the counter electrode, and the like are formed, which becomes the upper substrate (second substrate) 6 in the bonding step, has been subjected to degassing (S4).

Positioning recognition marks for opposing positions other than the portion surrounded by the sealant 3 on both substrates 1 and 6 are provided.
(For example, a cross). (In the present embodiment, the upper substrate 6 and the lower substrate 1 can be arranged in a reversed manner.) In that case, the names of the upper side and the lower side may be used in reverse.

Under these conditions, the substrates 1 and 6 are mounted on a liquid crystal cell manufacturing apparatus and bonded together, and the liquid crystal 4 is uniformly filled with no gap over the entire surface between the substrates 1 and 6. Thus, a liquid crystal cell is formed (S5).

FIG. 2 is a schematic structural view of a liquid crystal cell manufacturing apparatus according to the present invention. FIG. 3 is a top view of the glass substrate at that time.

The liquid crystal cell manufacturing apparatus is provided with a lower stage 12 on which a lower substrate 1 made of glass is mounted on a base 11, and a plurality of fixing pins 13 a, which are in contact with the outer periphery of the lower stage 12. 13n are implanted in the base 11.

Above the lower stage 12, an XYZθ moving mechanism 15 is provided with an upper stage 14 facing the lower substrate and holding the upper substrate 6 made of glass with predetermined positional accuracy.

A gripping mechanism 16 having a claw mechanism is provided on the outer periphery of the upper stage 14. This gripping mechanism 16 is provided with, for example, six movable holders 17a, 17b... 17f in a hook shape having a thickness of 0.3 mm to 0.5 mm, and these holders 17a, 17b. The lower surface of the substrate 6 is supported and gripped. The holding units 17a, 17b... 17f move and retreat at the time of an operation requiring retreat.

A projection mechanism 19 is provided on the upper stage 14 at a position corresponding to a line connecting the recognition marks 18a and 18b provided on the substrates 1 and 6. The tip of the protruding mechanism 19 is usually housed inside the upper stage 14, but the thickness of the gripping mechanism 16 is set to 0.3 mm to 1.0 mm from the lower surface of the upper stage 14 during operation.
The central part of the upper substrate 6 is pressed downward by projecting by an amount slightly larger than that.

The XYZθ moving mechanism 15 is fixed to a portal frame 21 provided on the base 11, and is driven in each direction of XYZθ by a driving source (not shown). Further, a cover 22 is provided outside the gate-shaped pedestal 21, thereby covering the entire portion formed also on the base 11. The inside of the cover 22 is connected to a vacuum pump (not shown) so that the inside can be depressurized. Also, the recognition mark 18 of the lower stage 12
Through holes 23 are formed at positions corresponding to a and 18b so that the recognition camera 24 and the UV irradiation means 25 built in the base 11 can act on the lower substrate 1 and the upper substrate 6, respectively. Are located.

Next, the operation of the liquid crystal cell device having such a configuration will be described. FIGS. 4A to 4D are process diagrams showing the operation of the liquid crystal cell manufacturing apparatus. 4 (a) to 4 (d), the same reference numerals are given to the same functional portions as those in FIG. 3, and the individual description is omitted.

The bonding operation is performed as shown in FIG.
First, the inside of the vacuum chamber is evacuated. Further, the lower substrate 1 placed on the lower stage 12 is fixed to the fixing pins 13a, 1a.
13n, and the upper substrate 6 is fixed on the lower surface of the upper stage 14 by the recognition marks 18a, 18b of the upper substrate 6.
In the vicinity of the opposite side (longitudinal direction) without
It is gripped by a gripping mechanism 16 of about 0.3 mm.

Next, as shown in FIG.
Are projected from the lower surface of the upper stage 14 to project on a line connecting the recognition marks (18a, 18b shown in FIG. 3) of the upper substrate 6, and the upper substrate 6 is bent downward in a bow shape.

At this time, the projecting amount z of the projecting mechanism 19 exceeds the sum of the thickness of the upper substrate 6, the thickness of the gripping mechanism 16, and the amount of bending of the upper substrate 6 due to its own weight, and does not damage the upper substrate 6. It is necessary to be on the order.

The maximum value Vmax (m) of the amount of deflection of the upper substrate 6 due to its own weight includes the thickness t (m) of the upper substrate 6, the density ρ (1) of the upper substrate 6, and the Young's modulus E ( P
a) and a function of the dimensions A (m) and B (m) shown in FIG. 3 and are expressed by the following equation.

[0031] Vmax = the A ³ F / (384EI) but ^{I = Bt 3/12 F =} 9800ρABt Specifically, for example, 550 × 60mm, t = 0.7m
When the short side is gripped by a glass substrate of m, ρ = 2.7 g / cm ³ and E = 75 GPa, and A = 550 mm and B = 400 mm, Vmax is about 0.8 mm.

At this time, if the thickness of the substrate holding mechanism 16 is, for example, 0.5 mm, the projecting amount z of the projecting mechanism 19 is 1
mm.

In this state, as shown in FIG.
The Zθ moving mechanism 15 is driven, and a recognition camera (position recognition mechanism) 24 housed in the base 11 is used to drive both substrates 1, 6.
The upper substrate 6 is moved closer to the lower substrate 1 while detecting and positioning the recognition marks 18a and 18b. By this operation, the liquid crystal 4 dropped on the surface of the lower substrate 1 flows and spreads to a uniform thickness, and the substrates 1 and 6 are temporarily fixed by the UV-curable sealing agent 26 for temporary fixing. It is fixed.

This temporary fixing operation is performed by the XYZθ moving mechanism 1
The recognition marks 18a and 18b are recognized by the movement and rotation control in the horizontal plane and the movement in the up and down direction by 5, and thereafter, the adjustment (alignment) → the mark recognition → the adjustment → the mark recognition is repeated a plurality of times. Thereby, at least the UV curable sealant 2 for temporary fixing
When the substrates 1 and 6 come into contact with 6 and positioning is completed, UV is locally applied to the contact portion by UV irradiation means 25 so that the two substrates 1 and 6 do not relatively shift. Temporarily fix.

Thereafter, as shown in FIG. 4D, the substrate holding mechanism 16 and the projecting mechanism 19 are retracted, and are made flush with the line connecting the projecting recognition marks 18a and 18b of the upper substrate 6. Next, a portion other than on the line connecting the recognition marks 18a and 18b of the upper substrate 6 is extruded to form a gap. Finally, the entire surface of the UV-curable sealant 3 is irradiated with UV by the UV irradiation means 24 to fix the two substrates 1 and 6, thereby completing the bonding and manufacturing a liquid crystal cell.

In the above-described embodiment, the XYZθ moving mechanism 15 is installed on the upper stage 14 side.
An arbitrary axis such as an XY axis may be installed on the lower stage 12 side. Further, the entire XYZθ moving mechanism 15 is connected to the lower stage 12.
It may be installed on the side. In short, both substrates 1 and 6 are relatively X
What is necessary is just to be able to move in the YZθ directions.

In the above-described embodiment, the movable projection mechanism 19 is provided on the upper stage 14 side.
9 may be provided on the lower stage 12 side.

In the above-described embodiment, after the UV temporary fixing is completed, the recognition marks 18a,
Although other portions other than on the line connecting 8b are extruded, the same gap may be formed by a press effect by atmospheric pressure when the inside of the chamber is opened to atmospheric pressure. Further, the operation of pushing out other parts other than the vicinity of the recognition marks 18a and 18b may be omitted, and the entire surface may be irradiated with UV after opening to the atmosphere.

Further, in the above-described embodiment, the UV-curable sealing agent and the UV-temporary sealing agent are formed on the lower substrate, but they may be formed on the upper substrate. May be separately formed on the upper substrate and the lower substrate.

According to the above-described method of manufacturing a liquid crystal cell, unlike the conventional manufacturing method, in which the upper substrate is held by vacuum suction, regardless of the degree of vacuum in the atmosphere in the chamber, Since the upper substrate can be securely held, it can be sufficiently used even when a high degree of vacuum is required in the process, so that it can be used.

In the conventional manufacturing method, the positioning is performed in a state where the gap forming spacer is in contact with the opposing substrate. However, in the present embodiment, unlike the conventional manufacturing method, the bonding is performed while positioning both substrates. Because of the matching, it is possible to prevent a product defect caused by the gap forming spacer dragging on the substrate surface as in the conventional manufacturing method.

Further, since the central portion of the upper substrate can be bent by a predetermined amount according to the size of the substrate, the liquid crystal can be quickly filled between the two substrates to a uniform thickness.

[0043]

According to the present invention, a high-precision and high-quality liquid crystal display device can be manufactured by a manufacturing process with a short tact time.

[Brief description of the drawings]

FIG. 1 is a manufacturing process diagram of a liquid crystal cell.

FIG. 2 is a schematic configuration diagram of a liquid crystal cell manufacturing apparatus of the present invention.

FIG. 3 is a top view of a glass substrate.

4 (a) to 4 (d) are process diagrams showing the operation of the liquid crystal cell manufacturing apparatus of the present invention.

FIG. 5 is a schematic configuration diagram of a conventional liquid crystal cell manufacturing apparatus.

FIG. 6 is a top view of a glass substrate.

FIGS. 7A and 7B are explanatory diagrams of an operation of a conventional liquid crystal cell manufacturing apparatus.

FIG. 8 is an explanatory view of a conventional method of holding a substrate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lower substrate, 3 ... Sealant, 4 ... Liquid crystal, 6 ... Upper substrate, 12 ... Lower stage, 14 ... Upper stage, 15 ... XY
Zθ moving mechanism, 16: gripping mechanism, 18a, 18b: recognition mark, 19: projecting mechanism

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H089 MA03Y NA22 NA32 NA35 NA42 NA44 NA45 NA48 NA49 NA56 NA60 QA12 QA13 QA14 5G435 AA17 BB12 EE33 KK03 KK05 KK10

Claims (4)

[Claims] 1. A step of mounting a first substrate on a lower stage, a step of holding a second substrate on an upper stage, and a sealing agent for sealing at least one of the first and second substrates. Applying a liquid crystal to a predetermined position of the first substrate; disposing the first and second substrates to face each other; and performing relative positioning based on alignment marks provided on each substrate. Performing a step of projecting at least a part of at least one of the first and second substrates toward the other substrate facing the other substrate, and bringing the two substrates closer to a predetermined gap; A method of manufacturing a liquid crystal display device. 2. A lower stage for holding a first substrate; an upper stage for holding a second substrate; moving means for relatively moving the first and second substrates; Sealant applying means for applying a sealant for sealing to at least one of the two substrates; and position recognizing means for recognizing respective substrate positions from alignment marks provided on the first and second substrates, respectively. And control means for driving the moving means based on the respective substrate positions recognized by the position recognizing means to position the first and second substrates, wherein the first and second substrates are aligned. An apparatus for manufacturing a liquid crystal display device, comprising: a projecting means for projecting a part of at least one of the two substrates toward the other substrate. 3. The liquid crystal according to claim 2, wherein said holding means for said second substrate provided on said upper stage is a claw mechanism for supporting a part of the outer periphery of said second substrate. Display device manufacturing equipment. 4. The apparatus for manufacturing a liquid crystal display device according to claim 2, further comprising a liquid crystal applying means for applying a liquid crystal to a predetermined position of said first substrate.