JPH09318955A - Apparatus for producing liquid crystal element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for producing a liquid crystal element with which the improvement in the uniformity of a cell gap is possible. SOLUTION: Two sheets of opposite substrates are adhered by a pressing means 7 in such a manner that a spacing is formed therebetween by a sealant of a thermosetting type forming the space for sealing liquid crystals together with the opposite substrates and a granular thermosetting type adhesive. At the time of pressing, the sealant and the adhesive are heated by a heating means, by which the sealant and the adhesive are cured. The pressing means 7 are composed of a first pressing means 7a for pressing the prescribed parts disposed with the sealant of the substrates and a second pressing means 7b for pressing the other parts. The independent setting of the pressing force of the respective first and second pressing means 7a, 7b is made possible, by which a desired pressure distribution is generated in the substrates and the uniformity of the cell gap is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device manufacturing apparatus, and more particularly to a thermosetting as a sealing agent for enclosing liquid crystal injected into two opposing substrates and a granular adhesive for adhering the substrates. It is about using the type one.

[0002]

2. Description of the Related Art Conventionally, in a liquid crystal device manufacturing apparatus for manufacturing a liquid crystal device by injecting a liquid crystal between the substrates after adhering two facing substrates with a gap therebetween, The bonding is performed by using a sealing agent that bonds the substrate and forms a space for enclosing the liquid crystal together with the substrate, and a granular adhesive that bonds the substrate.

By the way, there are cases where thermosetting type sealing agents and adhesives are used, and as a method for adhering substrates using such thermosetting type sealing agents or the like, two substrates are stacked. After the alignment, the alignment is performed, and thereafter, the entire surface of the substrate is set at 100 to 200 ° C. while being pressed with a pressure of 0.1 to 5.0 Kg / cm ^{2 in} order to suppress the stress of the substrate due to thermal expansion during heating. A common method is to cure in an oven.

At this time, as a pressing method for suppressing the irregularity of the substrate, there are, for example, a method of applying a load to the entire surface of the substrate using a weight, a method of a pressing jig using air pressure, a spring load and the like. Further, there is also proposed a device using a planar heating element that can increase the temperature rising speed and the cooling speed and can downsize the device.

[0005]

However, since all of these methods are methods of uniformly pressing the surface of the substrate, in the conventional liquid crystal device manufacturing apparatus adopting these methods, there is no sealant present portion. There is a problem that it is difficult to secure a uniform gap because the gap between the substrates (hereinafter referred to as a cell gap) is different from the display area without the sealant.

In particular, an element using a ferroelectric liquid crystal has a cell gap of about 1 μm, which is smaller than that of the elements of other systems, so that this influence becomes large. For this reason, conventionally, a certain amount of space has been provided between the display area and the seal portion, but this has a problem that a wasteful space is generated.

On the other hand, a method has been proposed in which the density of the granular adhesive is changed within the display surface in order to prevent defective injection due to volume contraction in the cooling process after the liquid crystal is injected into the ferroelectric liquid crystal device (special feature. Kaihei 2-43518). However, in such a case, since the adhesive particle density varies depending on the location, there is a problem that the cell gap varies in the method of processing the substrate surface with a uniform pressure.

Therefore, the present invention has been made in order to solve such problems, and an object thereof is to provide a liquid crystal device manufacturing apparatus capable of improving the uniformity of the cell gap. .

[0009]

According to the present invention, there is provided a liquid crystal element manufacturing apparatus for manufacturing a liquid crystal element by injecting liquid crystal between the two substrates after adhering two opposing substrates in a state where a gap is formed. A thermosetting sealant that forms a space for enclosing the liquid crystal together with the opposing substrate while adhering the substrate, a granular thermosetting adhesive that adheres the substrate, and the substrate The pressing means for pressing the substrate so that it adheres, and the heating means for heating the sealing agent and the adhesive so as to cure the sealing agent and the adhesive when pressed by the pressing means. The predetermined part of the substrate on which the sealant is arranged and the other part are independently pressed.

According to the present invention, the pressing means comprises first pressing means for pressing a predetermined portion of the substrate and second pressing means for pressing the other portion, and the first pressing means is also provided.
The pressing force of the second pressing means and the pressing force of the second pressing means can be set independently of each other.

The present invention is also characterized in that the pressing means presses the substrate by the pressure of gas.

Further, the present invention is characterized in that the heating means is arranged outside the two substrates so as to heat the sealant and the adhesive through the substrates.

Further, in the present invention, the liquid crystal is a ferroelectric liquid crystal.

The present invention is also characterized in that the sealing agent contains an adhesive, and the adhesive and the granular adhesive contained in the sealing agent are thermosetting epoxy resins.

Further, as in the present invention, a thermosetting sealant for forming a space for enclosing a liquid crystal together with the opposing substrates and a granular thermosetting adhesive separate the two opposing substrates from each other. The substrate is pressed by the pressing means so that the sealing agent and the adhesive are cured so that the sealing agent and the adhesive are hardened by heating the sealing agent and the adhesive at the time of pressing. Further, the pressing means is configured to independently press a predetermined portion of the substrate where the sealant is arranged and the other portion, so that a desired pressure distribution can be created on the substrate. .

The pressing means is composed of first pressing means for pressing a predetermined portion of the substrate and second pressing means for pressing the other portions, and the pressing forces of the first and second pressing means are independent of each other. The desired pressure distribution can be created on the substrate by enabling the setting.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a liquid crystal device manufacturing apparatus according to an embodiment of the present invention. In FIG.
Reference numerals a and 1b are planar heating elements serving as heating means, and 2a and 2b are a pair of substrates on which the planar heating elements 1a and 1b are arranged outside. A sealant for liquid crystal cells (hereinafter referred to as a sealant) is provided on at least one of the substrates 2a and 2b.
And a granular adhesive (hereinafter referred to as adhesive bead).

Reference numerals 3a and 3b are heater plates (t = t) for heat equalization, which are made of aluminum and which constitute the sheet heating elements 1a and 1b.
1 mm), 4a, 4b are aluminum plates for soaking (t = 3 m)
m), in which the temperature control sensor (not shown) of the planar heating element 1 is embedded. 5a and 5b are cushioning materials for equalizing the pressure received by the substrates 1a and 1b, 6 is an aluminum plate (t = 8 mm) for pressurization, and 7 is a gas for pressing the substrates 1a and 1b in order to suppress the misalignment of the substrates 1a and 1b. The air bag is a pressing unit that presses by the pressure of (air). The aluminum plate 6 for pressurization plays a role of suppressing the airbag 7.

Here, the airbag 7 is divided according to, for example, the shape of the sealant in each of the examples described later. Then, by controlling the pressures of the respective divided portions of the airbag 7 separately, the substrates 1a and 1b are controlled.
The desired pressure distribution can be easily created, and the uniformity of the gap can be improved. In addition, 8 is an air pipe for supplying air to the airbag 7.

Next, a first example of the present embodiment of the liquid crystal device manufacturing apparatus using the divided airbag will be described.

In this embodiment, as shown in FIG. 2, one glass substrate with a transparent electrode (450 mm × 5) which has been subjected to orientation treatment is used.
50 mm, t = 1.1 mm) 1a, a sealing agent (not shown) formed of a thermosetting epoxy resin by a screen printing method and containing an adhesive (manufactured by Mitsui Toatsu Chemical Co., Inc., trade name Struct Bond XN-21). -F) 10 is printed, and thereafter, adhesive beads 11 (trade name Trepal manufactured by Toray Co., Ltd.) formed of a thermosetting epoxy resin having an average particle diameter of 5.6 μm are sprayed at an average density of 100 beads per 1 mm ^2. did. In addition,
As shown in the figure, the sealant was formed in a single pattern.

Further, another glass substrate 1b with a transparent electrode, which has been subjected to an orientation treatment, has an average grain size of 1.2 μm (not shown).
m spacers (trade name: silica micro beads, manufactured by Catalysts & Chemicals Industries Co., Ltd.) were sprayed at a density of 300 per 1 mm ² .

Next, the two glass substrates 2a and 2b are bonded to each other, and as shown in FIG. 1, a cushioning material (manufactured by Bridgestone Co., trade name Barlite Scott Felt, t = 1 mm) 5a, 5b and a planar heating element (Sakaguchi Dentsu Co., Ltd., trade name Samicon 230, watt density 1 W / cm ² ) 1a, 1b are arranged, and a glass substrate 2a,
The sealant 10 and the adhesive bead 11 are heated by directly heating 2b with the soaking heater plates 3a, 3b, 4a, 4b.

Next, the pressing aluminum plate 6 and the air bag 7 were set on the glass substrates 2a and 2b sandwiched between the sheet heating elements 1a and 1b. In this embodiment, the airbag 7 has only the edges of the substrates 2a and 2b, which are the predetermined portions (see FIG. 2) where the sealant 10 of the substrates 2a and 2b is arranged as shown in FIG. The outer airbag 7a, which is the first pushing means for pushing, and the inner airbag 7b, which is the second pushing means for pushing the central portion corresponding to the display portion of the substrates 2a, 2b, which is the other portion, are formed separately.

Further, different air pressures are applied to the outer air bag 7a and the inner air bag 7b, that is, 1 kg / cm ² is applied to the inner air bag 7b and 2 kg / cm ² is applied to the outer air bag 7a. In FIG. 3, 8a is a first air tube for supplying air to the outer airbag 7a, and 8b is a second air tube for supplying air to the inner airbag 7b.
It is an air tube. Then, these first and second air pipes 8
By supplying air to the outer airbag 7a and the inner airbag 7b independently from a and 8b, the pressing force of the outer airbag 7a and the inner airbag 7b can be set independently. ing.

The air bag 7 is divided in this way, and the outer air bag 7a corresponding to the sealant 10 is formed.
It is possible to easily create a desired pressure distribution on the substrates 1a and 1b by applying a large pressure to the cell 1 and prevent a cell gap difference between the cell gap where the sealant 10 is present and the display section from occurring. it can.

On the other hand, after pressing the substrates 2a and 2b by the air bag 7 in this manner, the sheet heating element 1 was energized. At this time, the temperature controller connected to the temperature sensor in the heater plate 4 was set at 160 ° C. It should be noted that it takes 10 to 15 before the substrates 2a and 2b reach 150 ° C.
It took a minute. Further, after that, the substrate was kept at 150 ° C. for 1 hour and then naturally cooled, and then the substrates 2a and 2b were taken out. Finally, after scribing and breaking the substrates 2a and 2b, a pyrimidine-based ferroelectric liquid crystal was injected to manufacture a liquid crystal element.

By the way, after that, when the cell gap of the substrates 2a and 2b was measured by the retardation method, the result was as shown in the graph of FIG. The cell gap was measured at 5 mm intervals along the line indicated by the dotted line in FIG.

On the other hand, as a comparative example of the liquid crystal device manufactured as described above, a pair of substrates 2a and 2b are manufactured by the same method as that of this embodiment.
After bonding, the substrates 2a and 2b were set as shown in FIG. 1, and the substrates 1a and 1b were pressed by the undivided airbag 7A as shown in FIG.
The air pressure at this time was 1 kg / cm ² , and the other conditions were the same as in this example. Then, when the cell gap was measured in the same manner as in this example, the result was as shown in the graph of FIG.

Here, as is clear from the graphs of FIGS. 4 and 6, when the airbag 7A which is not divided is used, the cell gap in the portion where the sealant 10 is present is larger than that in the display portion. On the contrary, the divided airbag 7 is used, and the outside airbag 7 corresponding to the sealant portion around
When the pressure of a is made larger than the pressure of the inner airbag 7b corresponding to the display portion (double in the case of this embodiment), the cell gap difference between the portion where the sealant 10 is present and the display portion. Does not occur.

Next, a second embodiment will be described in which the sealant pattern is a two-piece pattern as shown in FIG.

In this embodiment, the air bag 7 corresponds to the sealant 10 having a two-piece pattern, and the outer air bag 7 corresponds to the seal 10 as shown in FIG.
a and a central portion 7b, 7c corresponding to the two display portions, while being divided into an outer airbag 7a and an inner airbag 7b.
Have different air pressures, that is, the inner airbag 7b,
1kg / cm ^{2 for} 7c and 2kg for outside airbag 7a
/ Cm ^2, and a liquid crystal element was manufactured by the same method as in the first embodiment.

Then, by the same method as in the first embodiment,
When the cell gap was measured, the result was as shown in the graph in FIG. In FIG. 8, 8a denotes a first air pipe for supplying air to the outer airbag 7a, 8b,
8c is a second for supplying air to the inner airbags 7b, 7c
And the third air tube.

On the other hand, as a comparative example of this liquid crystal element, after a pair of substrates 2a and 2b were bonded by the same method as this embodiment, the substrates 2a and 2b were set as shown in FIG. The substrates 1a and 1b are pressed by the airbag 7A which is not divided as shown in FIG. The air pressure at this time was 1 kg / cm ² , and the other conditions were the same as in this example. Then, when the cell gap was measured in the same manner as in this example, the result was as shown in the graph in FIG.

As is apparent from FIGS. 9 and 10, when the air bag 7A which is not divided is used, the cell gap in the portion where the sealant 10 is present becomes larger than that in the display portion, and particularly, in the substrates 2a and 2b. Since the sealant 10 is close to the central portion, the tendency is large. On the other hand, when the pressure of the outside airbag 7a corresponding to the sealant portion is made larger than the pressure of the inside airbags 7b and 7c corresponding to the display portion by using the divided airbag 7 (in the case of the present embodiment, it is doubled). ), There is no difference in cell gap between the cell gap where the sealant 10 is present and the display portion.

Next, a third example of the present embodiment will be described.

In this example, liquid crystal elements having different adhesive bead existing densities within the display surface were prepared. The pattern of the sealant 10 was set to 1-up pattern (see FIG. 2), the density of the adhesive bead 11 and 200 / cm ² by the shaded portion of FIG. 2, the other portions 100 / cm ²
And

On the other hand, the aluminum plate 6 for pressurization and the air bag 7
Used the one shown in FIG. Here, as shown in the figure, the airbag 7 includes a plurality of outer small airbags 7a ', 7a' formed by further dividing the outer airbag 7a.
d and a plurality of inner small airbags 7b 'formed by further dividing the inner airbag 7b so as to be surrounded by a thick line. In the figure, 8a ', 8
Reference numeral d denotes a first small air pipe for supplying air to the outer small air bags 7a 'and 7d, and 8b' denotes a second small air pipe for supplying air to the inner small air bags 7b '.

Then, the air pressure is adjusted to the inner small air bag 7b '.
1 kg / cm ^{2 on} the outside, while a small outside air bag 7
2 kg / cm ^{2 is} applied to each outer small airbag 7a 'of the portion corresponding to the sealant 10 among a'and 7d, and the portion having a high density of the adhesive beads 11 (hatched portion in FIG. 2) The outside small airbag 7d has 1.5 kg /
A liquid crystal element was manufactured in the same manner as in Example 1 by applying cm ² .

Then, in the same manner as in the first embodiment,
The cell gap was measured at 5 mm intervals along the line indicated by the dotted line in FIG. 2, and the result was as shown in the graph in FIG.

On the other hand, as a comparative example of this liquid crystal element, a pair of substrates 2a and 2b were bonded together by the same method as in this example. Then, the substrates 2a and 2b were set as shown in FIG. 1, and the substrates 1a and 1b were pressed by an undivided airbag 7A as shown in FIG. The air pressure at this time was 1 kg / cm ² , and the other conditions were the same as in this example. Then, when the cell gap was measured in the same manner as in this example, the result was as shown in the graph of FIG.

As is apparent from FIGS. 12 and 13, when the airbag 7A which is not divided is used, the cell gap of the portion where the sealant 10 is present and the adhesive bead 1 are used.
The cell gap in the portion where the existing density of 1 is large becomes larger than that in the display portion. On the contrary, by using the divided airbag 7, the pressure of the outer airbag 7a 'corresponding to the sealant portion is made larger than the pressure of the inner airbag 7b' corresponding to the display portion (double in the case of this embodiment), Further adhesive beads 11
When the pressures of the outer airbags 7a ′ and 7d are changed according to the existing density of the (the amount of change of 1.5 times in the case of the present embodiment)
Does not cause a cell gap difference between the cell gap where the sealant 11 is present and the display portion, and the cell gap in the display portion is also uniform.

[0044]

As described above, according to the present invention, the pressing means for pressing the substrate so that the substrate is adhered is provided independently of the predetermined portion where the sealant of the substrate is arranged and the other portion. By configuring to press, it is possible to easily create a desired pressure distribution and improve the uniformity of the gap.

[Brief description of drawings]

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

FIG. 2 is a schematic diagram showing a seal shape and a gap measurement point according to the first example of the above embodiment.

FIG. 3 is a schematic diagram showing the shapes of a pressing aluminum plate and an airbag according to the first embodiment.

FIG. 4 is a chart showing cell gap measurement results in the first embodiment.

FIG. 5 is a schematic diagram showing the shapes of an aluminum plate for pressurization and an airbag according to a comparative example of the first embodiment.

FIG. 6 is a chart showing cell gap measurement results in the comparative example.

FIG. 7 is a schematic diagram showing a seal shape and a gap measurement point according to a second example of the above embodiment.

FIG. 8 is a schematic diagram showing the shapes of a pressure aluminum plate and an airbag according to the second embodiment.

FIG. 9 is a chart showing cell gap measurement results according to the second embodiment.

FIG. 10 is a chart showing cell gap measurement results according to a comparative example of the second embodiment.

FIG. 11 is a schematic diagram showing the shapes of a pressing aluminum plate and an airbag according to a third example of the above-described embodiment.

FIG. 12 is a chart showing cell gap measurement results according to the third embodiment.

FIG. 13 is a chart showing cell gap measurement results according to a comparative example of the third embodiment.

[Explanation of symbols]

 1a, 1b Sheet heating element 2a, 2b Substrate 7,7A Air bag 7a, 7a ', 7d Outer air bag 7b, 7b' Inner air bag 8 Piping 10 Sealant 11 Adhesive beads

Claims (6)

[Claims] 1. A liquid crystal device manufacturing apparatus for manufacturing a liquid crystal device by injecting a liquid crystal between the substrates after bonding two opposing substrates in a state where a gap is formed, while bonding the substrates. A thermosetting sealant that forms a space for enclosing the liquid crystal together with the opposing substrate, a granular thermosetting adhesive that adheres the substrate, and presses the substrate so that the substrate adheres. And a heating unit that heats the sealing agent and the adhesive so as to cure the sealing agent and the adhesive when the pressing unit presses the sealing agent of the substrate. An apparatus for manufacturing a liquid crystal element, characterized in that it is configured to press a predetermined portion and the other portions that are arranged independently of each other. 2. The pressing means comprises first pressing means for pressing a predetermined portion of the substrate and second pressing means for pressing the other portion, and the pressing means for pressing the first and second pressing means. The liquid crystal element manufacturing apparatus according to claim 1, wherein the pressures can be set independently of each other. 3. The liquid crystal element manufacturing apparatus according to claim 1, wherein the pressing means presses the substrate by the pressure of gas. 4. The liquid crystal element according to claim 1, wherein the heating means is arranged outside each of the two substrates so as to heat the sealant and the adhesive through the substrates. Manufacturing equipment. 5. The liquid crystal device manufacturing apparatus according to claim 1, wherein the liquid crystal is a ferroelectric liquid crystal. 6. The liquid crystal device according to claim 1, wherein the sealant contains an adhesive, and the adhesive and the granular adhesive contained in the sealant are thermosetting epoxy resins. apparatus.