JPH11231328A - Method and device for sticking liquid crystal substrates to each other - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal substrate sticking method which sticks two substrates, which are arranged in opposite positions to each other with a high precision. SOLUTION: One substrate 23 which has the front face coated with a seal agent 21 and has a liquid crystal material 22 arranged on the inside of this seal agent 21 has the outer periphery fixed and is put in a vacuum vessel 30, and all the outer front face of the other substrate 26 which is arranged so as to face one substrate 23 with a prescribed gap between them is fixed by vacuum attraction of a vacuum attraction mechanism 27. Both substrates 23 and 26 are aligned by relative movement in longitudinal and lateral directions of substrate surfaces, and at least one substrate is moved in the direction perpendicular to the substrate surface, and one substrate 23 and the other substrate 26 are stuck to each other with the seal agent 21 between them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bonding a liquid crystal substrate constituting a liquid crystal display element used as an image display panel of a personal computer, a TV set or the like.

[0002]

2. Description of the Related Art As a structure of a liquid crystal substrate constituting a liquid crystal display element, as shown in FIG. 6, an ultraviolet-curable adhesive (sealant) 3 is disposed on the surface of a lower substrate 1 made of a translucent material. The upper substrate 2 made of a light-transmissive material disposed to face the lower substrate 1 is attached to the lower substrate 1 via a sealant 3 and further shown in FIG. As described above, there is known a device in which the liquid crystal material 4 is arranged inside the sealant 3.

As a method of disposing the liquid crystal material 4 inside the sealant 3, as shown in FIG. 7B, the liquid crystal material 4 is dropped inside the sealant 3, and thereafter, FIG. As shown in FIG.
UV light is applied to cure the sealant 3 so that the lower substrate 1
A liquid crystal dropping method for completing a panel by bonding an upper substrate via a sealant 3 is known. Next, a method for bonding a liquid crystal substrate by a conventional liquid crystal dropping method will be described in further detail with reference to FIG. I do.

[0004] As shown in FIG.
The lower substrate 1 which is an array substrate in which a liquid crystal material 4 is disposed inside the ultraviolet-curing type sealant 3 coated with m and the sealant 3 is mounted on a horizontally movable table 5, and the periphery thereof is mounted. Is fixed with fixing pins 6.

[0005] Next, as shown in FIG.
The lower substrate 1 is fixed by arranging spacers 7 made of a Teflon material having a thickness of 5 mm around the lower substrate 1 so as not to contact the sealant 3.

[0008] Then, as shown in FIG. 8 (c), the upper substrate 2, which is a color filter substrate, is arranged on a plurality of spacers 7, and then the table 5 on which the lower substrate 1 is mounted is horizontally moved back and forth and right and left. Then, the lower substrate 1 and the upper substrate 2 are aligned. As a method of aligning the lower substrate 1 and the upper substrate 2, for example, the lower substrate 1 made of a translucent material is used.
And the position reference marks (not shown) respectively written on the upper substrate 2 are viewed from above the upper substrate 2 to determine whether the position reference marks on the surface of the lower substrate 1 match the position reference marks on the upper substrate 2. After confirming that these position reference marks match, alignment is performed.

[0008] Further, as shown in FIG. 8 (d), the upper substrate 2 is pressed vertically downward, each spacer 7 is removed in this state, and the upper substrate 2 is bonded to the lower substrate 1 via the sealant 3. .

[0008] Thereafter, as shown in FIG. 8 (e), ultraviolet rays are irradiated from an ultraviolet lamp 10 to cure the sealant 3, and the bonding of the lower substrate 1 and the upper substrate 2 is completed.

However, in the above-described conventional method of bonding substrates, when the upper substrate 2 is brought into contact with the sealant 3 on the surface of the lower substrate 1, that is, when the spacer 7 is removed, the upper substrate 2 is restricted or supported. Therefore, when the upper substrate 2 moves down, 3 μm in the substrate surface direction (front-back, left-right direction).
m or more, and there is a problem in that, for example, an image defect occurs due to a displacement in a liquid crystal display.

In order to correct this deviation to within 3 μm, after the upper substrate 2 comes into contact with the sealing agent 3 on the surface of the lower substrate 1, the lower substrate 1 or the upper substrate 2 is moved in the direction of the substrate surface (front-back, left-right direction). In such a case, there is a problem that the sealant 3 is peeled off and the liquid crystal properties are impaired due to the diffusion and mixing of the sealant 3 and the liquid crystal material 4.

In order to solve this, for example,
A method for bonding a liquid crystal substrate shown in FIG. 9 has been proposed.

In the conventional method of bonding a liquid crystal substrate shown in FIG. 9, first, as shown in FIG. 9A, an ultraviolet-curable sealing material 3 is applied to the surface, and a liquid crystal is provided inside the sealing material 3. The lower substrate 1 on which the material 4 is disposed is mounted on a horizontally movable table 5, and the periphery of the lower substrate 1 is fixed with fixing pins 6.

Next, as shown in FIG. 9B, spacers 7 are arranged and fixed around the lower substrate 1 so as not to come into contact with the sealant 3 at the periphery.

Further, as shown in FIG.
Is placed on the spacers 7 arranged at several places,
The outer periphery of the upper substrate 2 is fixed by a guide member 8, and the table 5 on which the lower substrate 1 is mounted is moved in the front, rear, left and right horizontal directions,
The position reference mark (not shown) of the upper substrate 2 and the position reference mark (not shown) of the lower substrate 1 are matched to perform alignment between the lower substrate 1 and the upper substrate 2.

Next, as shown in FIG.
Is pressed in the vertical direction, the spacer 7 is removed in this pressed state, and the upper substrate 2 is moved in the direction perpendicular to the substrate surface along the end surface of the guide member 8, and the upper substrate 2 is To the lower substrate 1.

Finally, as shown in FIG. 9 (e), ultraviolet rays are irradiated from an ultraviolet lamp 10 to cure the sealant 3, and the bonding of the lower substrate 1 and the upper substrate 2 is completed.

As a method for improving the above method, a method of bonding liquid crystal substrates shown in FIG. 10 can be considered. In this method, first, as shown in FIG. 10A, an ultraviolet-curable sealing agent 3 is applied to the surface, and the lower substrate 1 on which the liquid crystal material 4 is disposed inside the sealing agent 3 is moved in the horizontal direction. Is mounted on a movable table 5, and the periphery of the lower substrate 1 is fixed with fixing pins 6.

Next, as shown in FIG. 10B, spacers 7 are arranged and fixed around the lower substrate 1 so as not to come into contact with the sealant 3 at the periphery.

Further, as shown in FIG.
Is placed on the spacers 7 arranged at several places,
The outer periphery of the upper substrate 2 is fixed by a guide member 8, and the table 5 on which the lower substrate 1 is mounted is moved in the front, rear, left and right horizontal directions, and the position reference mark (not shown) of the upper substrate 2 The lower substrate 1 and the upper substrate 2 are aligned with marks (not shown).
Align with.

Next, as shown in FIG. 10D, the spacer 7 is removed, and the upper substrate 2 is moved in the vertical direction together with the guide member 8 while the upper substrate 2 is fixed by the guide member 8 so that the upper substrate 2 is moved. It is bonded to the lower substrate 1 via the sealant 3 under a pressurized state.

Finally, as shown in FIG. 10 (e), the sealant 3 is cured by irradiating ultraviolet rays from an ultraviolet lamp 10, and the bonding of the lower substrate 1 and the upper substrate 2 is completed.

[0022]

However, in the above-described method of bonding the liquid crystal substrates shown in FIGS. 9 and 10, when the upper substrate 2 is disposed on the spacer 7, the warp is caused by the weight of the upper substrate 2. The upper substrate 2 is deformed due to, for example, the upper substrate 2 and the lower substrate 1 are aligned in this state, and even if the position reference mark of the upper substrate 2 and the position reference mark of the lower substrate match, the spacer 7, when the upper substrate 2 is brought into contact with the sealant 3, deformation such as warpage of the upper substrate 2 disappears, and the front and rear surfaces thereof become flat, and the position reference mark of the upper substrate 2 and the lower substrate 1 The state is shifted from the position reference mark.

For this reason, the upper substrate 2 is displaced from the lower substrate 1 by about 3 μm in the front-rear and left-right directions of the substrate surface, and the electrode pattern (not shown) formed on the lower substrate 1 in the completed liquid crystal display. There has been a problem that a color shift occurs due to a positional shift from a pixel (not shown) formed on the upper substrate 2 and an image defect occurs.

In order to correct this shift, after the upper substrate 2 comes into contact with the sealant 3, the lower substrate 1 or the upper substrate 2
When the substrate is moved in the front-rear and left-right directions of the substrate surface, the sealant 3 is peeled off, and the liquid crystal characteristics are deteriorated.

An object of the present invention is to solve the above-mentioned problems and to provide a method for bonding a liquid crystal substrate which can bond two substrates disposed at opposing positions with high accuracy.

[0026]

In order to achieve the above object, according to the present invention, a sealant is applied to the surface, and the outer periphery of one substrate on which a liquid crystal material is disposed is fixed inside the sealant. In this state, the outer surface of the substrate on the other side, which is arranged at a predetermined interval so as to face the substrate on one side, is fixed by vacuum suction by a vacuum suction mechanism, and both substrates are relatively moved back, forth, left, right, After moving in at least one direction, at least one substrate is moved in a direction perpendicular to the substrate surface, and the one side substrate and the other side substrate are bonded via the sealant. It is characterized by doing so.

In the present invention, it is preferable that at least the bonding is performed in a vacuum atmosphere.

Preferably, the degree of vacuum of the vacuum suction mechanism is higher than that of the vacuum atmosphere by 0.3 Torr or more.

Further, it is preferable to provide a vacuum sealing elastic body in the vacuum suction mechanism.

According to the present invention, since the positioning can be performed while the other substrate is suction-held on the flat surface by the vacuum suction mechanism, the other substrate is not deformed such as warpage. It is possible to accurately bond both substrates arranged at the positions where they are to be bonded. Further, when the bonding is performed at least in a vacuum atmosphere, good liquid crystal characteristics can be maintained.

At this time, if the degree of vacuum of the vacuum suction mechanism is set to a high vacuum of 0.3 Torr or more higher than the vacuum degree of the vacuum atmosphere, the suction of the substrate by the vacuum suction mechanism can be ensured.

Further, in the present invention, after the two substrates are relatively horizontally moved and aligned, the other substrate is moved in a direction perpendicular to the substrate surface along the guide member, or the other substrate is moved. When the substrate is fixed to the guide member and moved in the direction perpendicular to the substrate surface together with the guide member, and the substrate on one side and the substrate on the other side are bonded via the adhesive, Bonding accuracy of the two substrates arranged at the position where the two substrates are positioned can be suppressed to within the clearance of the guide member that regulates the substrate on the other side. Can be matched.

[0033]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a liquid crystal substrate bonding method and apparatus according to an embodiment of the present invention.

The method for bonding the liquid crystal substrates according to the first embodiment of the present invention will be described with reference to FIGS.

First, as shown in FIG. 1A, a UV-curable sealing agent 21 is applied to the surface,
A lower substrate (one substrate) 23 made of a translucent material (glass) in which a liquid crystal material 22 is disposed inside 1 is mounted on a horizontally movable table 24, and the outer periphery is fixed by fixing pins 25. Fix it.

Next, as shown in FIG.
3 is placed in a vacuum container 30 and
Upper substrate (substrate on the other side) made of translucent material (glass)
The entire outer surface of 26 is fixed by vacuum suction by a vacuum suction mechanism 27. Here, an infinite number of pores (not shown) are formed on the lower surface of the vacuum suction mechanism 27, and if the upper substrate 26 is suction-fixed by vacuum suction in these innumerable pores. Good.

Then, a position reference mark (not shown) written on the lower substrate 23 and a position reference mark (not shown) written on the upper substrate 26 are combined with a transparent portion (not shown) provided on the vacuum suction mechanism 27. And positioning is performed so that these position reference marks match.

Next, as shown in FIG. 1C, the vacuum suction mechanism 27 is lowered vertically, and the upper substrate 26 is bonded to the lower substrate 23 via the sealant 21 while applying pressure.

Thereafter, as shown in FIG. 1D, the lower substrate 23 and the upper substrate 26 are taken out of the vacuum vessel 30 together with the table 24 and irradiated with ultraviolet rays from an ultraviolet lamp 31 to cure the sealant 21. And the lower substrate 23 and the upper substrate 26
To complete the bonding.

According to the liquid crystal substrate bonding method of the first embodiment, the upper substrate 26 is vacuum-sucked by the vacuum suction mechanism 27, and positioning can be performed in a state where the flatness of the upper substrate is ensured. Therefore, the lower substrate 23 and the upper substrate 26 can be bonded with high accuracy.

When the degree of vacuum of the vacuum suction mechanism 27 is higher than that of the vacuum chamber 30 by 0.3 Ton or more, the suction of the upper substrate 26 can be surely performed.

Further, as shown in FIG.
7 is provided with a vacuum-sealing elastic body 28, and the upper substrate 26 is vacuum-sucked through the vacuum-sealing elastic body 28, so that the degree of vacuum of the vacuum suction mechanism 27 can be increased.
6 can be reliably performed.

Further, as shown in FIG. 3, when the outer periphery of the upper substrate 26 is fixed by fixing pins 29 provided on the vacuum suction mechanism 27, the upper substrate 26 can be securely fixed at a correct position.

When the upper substrate 26 is bonded to the lower substrate 23 via the sealant 21 by pressing the upper substrate 26 for a predetermined time or more, the bonding of the lower substrate 23 and the upper substrate 26 is ensured. This is particularly effective for bonding a liquid crystal substrate that requires flatness.

In the present embodiment, the positioning and the bonding are performed in a vacuum atmosphere in the vacuum vessel 30. However, the liquid crystal material 22 may be dropped and filled or the ultraviolet rays may be irradiated in the vacuum vessel 30. Alternatively, only the bonding may be performed in a vacuum atmosphere.

A method for bonding liquid crystal substrates according to the second embodiment of the present invention will be described with reference to FIG. Note that the same members and the same portions in the method for bonding the liquid crystal substrates according to the first embodiment described above are denoted by the same reference numerals and described. Also in the second embodiment, the positioning and the bonding can be performed in a vacuum container. In addition, the liquid crystal material can be dropped and filled and the ultraviolet irradiation can be performed in the vacuum container. Can be performed in an atmosphere.

First, as shown in FIG. 4A, a UV-curable sealing agent 21 is applied to the surface,
A lower substrate (one substrate) 23 having a liquid crystal material 22 disposed inside 1 is mounted on a horizontally movable table 24, and the outer periphery is fixed by fixing pins 25.

Next, as shown in FIG.
After the spacer 32 is set on the upper surface 3, the upper substrate 26 is vacuum-sucked by the vacuum suction mechanism 33, and the outer periphery of the upper substrate 26 is fixed by the guide member 34 in a state where the flatness is secured. In this state, the table 24 on which the lower substrate 23 is mounted is moved in the horizontal direction, and the lower substrate 23 and the upper substrate 26 are aligned. This alignment may be performed so that a position reference mark (not shown) written on the lower substrate 23 and a position reference mark (not shown) formed on the upper substrate 26 match when viewed from above.

Then, as shown in FIG. 4C, the vacuum suction state by the vacuum suction mechanism 33 is released, the upper substrate 26 is lowered vertically along the guide member 34, and the upper substrate 26 is sealed with a sealing material. The substrate 21 is bonded to the lower substrate 23 while being pressed through the substrate 21.

Thereafter, as shown in FIG. 4D, the sealing material 21 is cured by irradiating ultraviolet rays from an ultraviolet lamp 31 to complete the bonding of the lower substrate 23 and the upper substrate 26.

According to the liquid crystal substrate bonding method of the second embodiment, the upper substrate 26 and the lower substrate 26 are maintained in a state where the flatness of the upper substrate 26 is secured by the vacuum suction of the upper substrate 26 by the vacuum suction mechanism 33. 23 can be aligned,
The bonding accuracy of the upper substrate 26 and the lower substrate 23 disposed at the opposing positions can be suppressed within the processing accuracy of the guide member 34 that regulates the upper substrate 26, and the lower substrate 23 and the upper substrate 26 can be bonded with high accuracy. Can be.

Further, the upper substrate 26 is vacuum-adsorbed in advance by a vacuum suction mechanism (not shown), and the upper substrate 26 is fixed together with the guide member 34 with the upper substrate 26 fixed to the guide member 34 as shown in FIG. The upper substrate 26 and the lower substrate 23 may be bonded together via the sealing material 21 by being lowered vertically.

According to this, the upper substrate 2 is kept in a state where the flatness of the upper substrate 26 is secured by the vacuum suction of the vacuum suction mechanism.
6 and the lower substrate 23 can be aligned.
The lower substrate 23 and the upper substrate 26 can be accurately bonded.

[0054]

According to the present invention, two substrates disposed at opposing positions can be bonded with high positional accuracy, and a liquid crystal display having good liquid crystal characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view for explaining a method of attaching a liquid crystal substrate according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a state in which a vacuum sealing elastic body is provided in a vacuum suction mechanism.

FIG. 3 is a schematic cross-sectional view showing a state where the outer periphery of an upper substrate vacuum-sucked by a vacuum suction mechanism is fixed with fixing pins.

FIG. 4 is a schematic cross-sectional view for explaining a method of attaching a liquid crystal substrate according to a second embodiment.

FIG. 5 is a schematic cross-sectional view showing a state in which the upper substrate is lowered in a vertical direction together with a guide member.

FIG. 6 is an exploded perspective view for explaining a structure of a liquid crystal substrate.

FIG. 7 is a schematic cross-sectional view for explaining a liquid crystal dropping method.

FIG. 8 is a schematic cross-sectional view for explaining a conventional method of attaching a liquid crystal substrate.

FIG. 9 is a schematic cross-sectional view for describing another conventional example of a method of attaching a liquid crystal substrate.

FIG. 10 is a schematic cross-sectional view for explaining another method of attaching a liquid crystal substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Sealant 22 Liquid crystal material 23 Lower substrate (one side substrate) 24 Table 25 Fixed pin 26 Upper substrate (other side substrate) 27 Vacuum suction mechanism 28 Elastic body for vacuum sealing 29 Fixing pin 30 Vacuum container 33 Vacuum suction mechanism 34 Guide member

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Jiro Sumida 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A sealant is applied to a surface of a substrate, and a liquid crystal material is disposed inside the sealant. A predetermined interval is provided so as to face the substrate on one side in a state where the outer periphery of the substrate is fixed. After fixing the outer surface of the substrate on the other side arranged by vacuum suction by a vacuum suction mechanism and moving both substrates relatively in the front, rear, left and right directions of the substrate surface, at least one of the substrates is aligned. Is moved in a direction perpendicular to the substrate surface, and the one side substrate and the other side substrate are bonded via the sealant. 2. The method according to claim 1, wherein the bonding is performed at least in a vacuum atmosphere. 3. The method according to claim 2, wherein the degree of vacuum of the vacuum suction mechanism is higher than that of the vacuum atmosphere by 0.3 Torr or more. 4. The method according to claim 1, wherein an elastic body for vacuum sealing is provided in the vacuum suction mechanism. 5. After positioning both substrates relative to each other by horizontal movement, the other substrate is moved in a direction perpendicular to the substrate surface along a guide member, and the one substrate is 5. The method for bonding liquid crystal substrates according to claim 1, wherein the other substrate is bonded via the adhesive. 6. After positioning both substrates relative to each other by horizontal movement, the other substrate is moved in a direction perpendicular to the substrate surface together with the guide member while the other substrate is fixed to the guide member. The method according to any one of claims 1 to 4, wherein the substrate on one side and the substrate on the other side are bonded via the adhesive. 7. A substrate on one side having a surface coated with a sealant and a liquid crystal material disposed inside the sealant, and a substrate on the other side disposed opposite to the one side substrate. A fixing device for fixing an outer periphery of one substrate, a vacuum suction mechanism for fixing an outer surface of the other substrate by vacuum suction, and a fixing device. Positioning means for relatively positioning the two substrates by moving the vacuum suction mechanism relative to the front, rear, left and right directions of the substrate surface, and bonding both substrates by moving at least one substrate in a direction perpendicular to the substrate surface An apparatus for bonding a liquid crystal substrate, comprising: a bonding means; and a vacuum container having therein the fixing means, a vacuum suction mechanism, a positioning means, and a bonding means.