JPH05323250A - Method and device for manufacturing liquid crystal display element - Google Patents

Abstract

PURPOSE:To maintain the uniformity of the density distribution of scattered particles even if a spray nozzle for scattering spacers and adhesive beads and a substrate are put at a shorter distance and to increase the size of the substrate by moving the spray nozzle above the substrate. CONSTITUTION:The two-liquid spray nozzle 61 receives volatile dispersed liquid in a container 62 under negative pressure produced by the supply of gaseous N2 and sprays it on the substrate 65. Consequently, the liquid level in the container 62 gradually falls, but a photoelectric sensor 63 detects the liquid level at all times and the liquid level is corrected and controlled by an elevating machine. Consequently, the difference DELTAH=H2-H1 between the height H2 of the tip of the spray nozzle 61 and the height H1 of the liquid level of the dispersed liquid is held constant with precision + or -1/2d. Here, (d) is the interval between a couple of photoelectric sensors 63. Therefore, even when the liquid level in the container 62 falls, the amount of volatile dispersed liquid 60 sucked up by the two-liquid spray nozzle 61 does not decrease and the arrangement density of particulates 66 on the substrate 65 never decreases.

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 element, particularly a ferroelectric liquid crystal display element.

[0002]

2. Description of the Related Art Generally, in order to maintain a substrate interval (hereinafter referred to as cell thickness) of a liquid crystal display device, a spin coat method, a spray dispersion method or the like is used, and a spacer such as glass fiber, alumina beads, plastic beads, silica beads or the like. Is present on the substrate.

On the other hand, in recent years, there is a strong demand for a large area of a liquid crystal display element, and in order to realize a uniform cell thickness, a method similar to that of a spacer is used to realize a uniform cell thickness. Adhesive beads, such as epoxy resin spherical particle adhesives, are present on the substrate.

Among the above-mentioned methods, the spray-dispersion method has been widely used in terms of mass productivity and difficulty of a large-sized substrate. This spraying method is a method of spraying a volatile dispersion liquid in which fine particles of spacers or adhesive beads are mixed with a volatile dispersion medium such as alcohol or freon at a certain ratio, and then sprayed on a substrate, In this method, only the spacers and the adhesive beads are made to exist on the substrate by evaporating the volatile dispersion medium.

Further, in the fine particle spraying process, N ₂ gas is quantitatively supplied to a two-fluid spray nozzle, which is a suction system for liquid uptake, through a mass flow controller, and the fine particles are dispersed from a container installed at a fixed position by volatile dispersion. There are many methods of sucking up the liquid, spraying and distributing it.

In the spray spraying method, stirring is required to keep the particle concentration in the dispersion liquid uniform. For this stirring, stirrer stirring or ultrasonic stirring using an ultrasonic cleaning tank is equipped in the spraying apparatus. It was

In the pressure bonding process of the two substrates, the two substrates, in which the spacer material and the adhesive beads are dispersed and arranged, are bonded with a sealing material (thermosetting epoxy adhesive or the like), and then a constant load is applied. It was thermocompression bonded.

[0008]

However, in the above-mentioned conventional spray spraying method, since the spray nozzle is fixed, the spraying area is formed by the spacers or the adhesive beads sprayed from the tip of the spray nozzle. Since it is limited within the cone, when spraying on a large substrate, it was necessary to move the position of the spray nozzle away from the substrate. As a drawback of such a method, since the distance between the nozzle and the substrate is large, the adhesion efficiency of particles is extremely poor, and a large amount of spacers or adhesive beads are consumed,
There were times when the time required for spraying had to be long. Further, since the spacer used in the ferroelectric liquid crystal display element is fine particles of about 1 to 2 μm, when the spray nozzle is separated from the substrate, the time required for the drop cannot be ignored, which is a major factor in reducing productivity. ..
Further, in the above-mentioned spraying device, since the area to be sprayed is circular as described above, it is necessary to spray a wider area with respect to the size of the substrate to be sprayed, and it is difficult to downsize in space. There was a drawback.

In order to improve the rigidity of the liquid crystal display element,
In the case of a ferroelectric liquid crystal display device that uses adhesive beads,
In order to prevent the deterioration of the display quality of the liquid crystal display element due to the inclusion of fine particles such as the adhesive beads other than the liquid crystal substance, it is necessary to set a standard value for the disposition density of the fine particles and manage it with a certain tolerance.

However, in the spraying process using the above-mentioned two-fluid spray nozzle in which suction of the liquid is a suction method, the height of the liquid surface in the container is lowered and the spray nozzle sprays as the dispersion liquid is sprayed and consumed. There is a drawback in that the amount of the dispersion liquid in which the fine particles are dispersed is reduced, and the density of the fine particles dispersedly arranged on the substrate is reduced, and the density of the fine particles is below the standard value.

Further, in the spray spraying method, when stirrer stirring or ultrasonic stirring was used to stir the dispersion liquid, there were the following drawbacks. (1) When stirrer stirring is used Due to friction between the Teflon-coated stirrer and the adhesive beads, and the friction between the adhesive beads and the inner wall surface of the container, the adhesive beads are aggregated and become a large solid. For this reason, when the adhesive beads are arranged on the substrate and the two substrates are bonded together, the gap between the substrates is caused by the cohesive adhesive beads. (2) In the case of ultrasonic agitation High-frequency vibration (20 to 50 KHz) generated by ultrasonic waves causes the adhesive beads to collide with each other, and the adhesive and the inner wall surface of the container collide with each other, causing friction to agglomerate the adhesive beads. In this case, the agglomerated particles are not as large as in the above (1), but since the stirring method originally does not increase the flow of the liquid itself, the adhesive beads are attracted to the inner wall surface of the container by static electricity, and as a result, they actually exist in the dispersion liquid. The concentration of the particles to be used decreases, and there is a large difference in the density of the adhesive beads arranged in the plane of the substrate and between the substrates, resulting in instability.

By continuing to apply ultrasonic waves for a longer period of time, the temperature of the volatile dispersion liquid rises and the amount of evaporation thereof increases, so that the concentration of the adhesive beads in the dispersion liquid gradually increases, and the volatile dispersion liquid is disposed on the substrate. The density of the adhesive beads to be used also increases.

Further, in the pressure bonding step of the two substrates, when the pressure bonding is carried out under a constant load as described above, the pressure sensitive adhesive beads are pressed without being sufficiently heated and softened. After being scattered, it is melted and cured on one of the substrates through a curing step, and the adhesive beads cannot connect the two substrates, resulting in a problem that a sufficient adhesive effect cannot be obtained.

An object of the present invention is to provide a manufacturing method and a manufacturing apparatus of a liquid crystal display element having excellent display quality and impact resistance in view of the problems of the above conventional example.

[0015]

The above-mentioned objects can be achieved by the constitution of the present invention described below.

According to the first aspect of the present invention, since the spray nozzle for spraying the spacer and / or the adhesive beads in the spray spraying process moves above the substrate during the spray spraying, the distance between the substrate and the spray nozzle is reduced. Also,
The density distribution of the dispersed particles is kept uniform, and the size of the substrate can be increased.

That is, the first aspect of the present invention is, in a method of manufacturing a liquid crystal display device in which a liquid crystal is sandwiched between two substrates facing each other, a spacer for holding a space between the substrates and / or an adhesive for spot-bonding the substrates. Manufacturing of a liquid crystal display device, characterized in that, when the agent beads are arranged on the substrate by a spray dispersion method, the spray dispersion nozzle moves above the substrate, preferably in a plane parallel to the surface of the substrate. Is the way.

In the first aspect of the present invention, the method of moving the spray spraying nozzle is not particularly limited, but it is preferable to use the NC driving device from the viewpoint of smooth movement and controllability.

The first aspect of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a plan view schematically showing a structural example of an apparatus for moving a spray spraying nozzle according to the first method of manufacturing a liquid crystal display element of the present invention. In FIG.
Only the moving device and the substrate are shown. In the figure, 1 is a spray nozzle mounting shaft for spraying, 2a and 2b are NC driving devices for moving the spray nozzles in the X direction and the Y direction, respectively, and 3 is for fixing the NC driving device and the spray nozzle mounting shaft. Fixed axis, 4 is a stage for supporting the substrate,
Reference numeral 5 is a substrate, and 6 is a booth surrounding the entire spraying device.

FIG. 2 is a side view schematically showing a state where a spray nozzle is attached to the moving device of FIG. 1 and spacers and adhesive beads are sprayed on the substrate. In the figure, 7 is a spray nozzle for spraying, 8 is a tube for supplying a volatile dispersion liquid 10 in which spacers and adhesive beads are dispersed to the spray nozzle, and 9 is a volatile dispersion liquid 10.
Is a container for storing the ultrasonic wave, 11 is an ultrasonic wave generator for maintaining the dispersibility of spacers and adhesive beads during spraying, 12 is a pedestal for supporting the ultrasonic wave generator 11, and 13 is a schematic view of the spraying state. It is a cross-sectional shape of a conical spray liquid.

In the above apparatus, the spray nozzle 7 fixed to the spray nozzle mounting shaft 1 is moved in the plane parallel to the surface of the substrate 5 above the substrate 5 by the NC driving devices 2a and 2b in the XY directions, and the spacer and the adhesive are adhered. The volatile dispersion liquid 10 in which the fine particles of the agent beads are dispersed can be sprayed on the surface of the substrate 5.

The movement pattern of the spray nozzle 7 at this time can be arbitrarily determined, and any pattern can be applied as long as the fine particles can be arranged on the surface of the substrate 5 at a uniform density.

FIG. 3 is a sectional view showing an example of a ferroelectric liquid crystal display element manufactured by the first manufacturing method of the present invention. Reference numerals 31 and 31 ′ are a pair of substrates made of a glass plate, a plastic plate or the like, and 32 is a transparent electrode group formed in a predetermined pattern such as a strip pattern (for example, a scanning voltage applying electrode group in a matrix electrode structure). , 32 'are transparent electrode groups in a direction intersecting with 32 (for example, a signal voltage applying electrode group in the matrix electrode structure), 33, 33' are insulating films formed by a sputtering method or the like, 34, 34 'Is an alignment film formed by, for example, a printing method, 35 is a sealing material for sealing the pair of substrates 31, 31', 36 is a spacer for maintaining the cell thickness, 37 is a pair of substrates 31, 31 ' And 38 are a pair of substrates 31, 3
It is a ferroelectric liquid crystal sandwiched between 1 '. Reference numeral 30 indicates these cell structures.

Next, the second aspect of the present invention will be described.

A second aspect of the present invention is a method of manufacturing a liquid crystal display device, which comprises a liquid crystal sandwiched between two substrates facing each other.
During the fine particle spraying process of spraying spacers for holding the space between the substrates and / or adhesive beads for spot-bonding the substrates with a two-fluid spray nozzle in which suction of a liquid is a suction system, and disposing on the substrate, For example, as shown in FIG. 6, the relative value of the height of the liquid surface of the volatile dispersion liquid 60 in which the spacers and / or the adhesive beads are dispersed and the height of the tip of the spraying nozzle 61 (ΔH in the drawing). ) Is controlled to be constant or substantially constant. Further, in the apparatus for performing the fine particle spraying process, for example, the liquid level of the volatile dispersion liquid 60 is detected. A means for controlling the height of the liquid surface of the volatile dispersion liquid 60, which includes a photoelectric sensor and a drive unit 64 of an elevator for vertically moving the container 62 storing the volatile dispersion liquid 60, and a control unit 69. An apparatus for manufacturing a liquid crystal display element characterized by having.

According to the second aspect of the present invention described above, a decrease in the arrangement density of the fine particles due to consumption of the volatile dispersion is prevented, and particularly when the fine particles are adhesive beads, the decrease in the arrangement density of the adhesive beads is reduced. Accordingly, it is possible to manufacture a liquid crystal display element without lowering the impact resistance.

The second aspect of the present invention will be specifically described below with reference to the drawings.

FIG. 6 is a diagram schematically showing an example of the second liquid crystal display device manufacturing apparatus of the present invention.

In the figure, 61 is a two-fluid spray nozzle in which the liquid is taken in by suction, 66 is fine particles (for example, spacer material or adhesive beads), 62 is a volatile dispersion liquid 60 in which fine particles 66 are dispersed (for example, IPA). Is a container for storing liquid, 63 is a photoelectric sensor having a fixed height, which is a means for detecting the liquid level in the container 62, and 64 is a container 62.
The drive part of the elevator, which is a means for keeping the liquid level inside, a substrate 65 on which fine particles 66 are dispersed, 67 is a pipe for sending N ₂ gas to the two-fluid spray nozzle 61, and 68 is a two-fluid spray nozzle Reference numeral 61 is a pipe for sending the volatile dispersion liquid 60, 69 is a control unit for the elevator, and 70 is a mass flow controller for quantitatively supplying N ₂ gas to the two-fluid spray nozzle 61.

In the above apparatus, the two-fluid spray nozzle 61 takes in the volatile dispersion liquid 60 in the container 62 by the negative pressure generated by the supply of N ₂ gas and sprays it toward the substrate 65. Although the liquid level in the container 62 gradually drops as the liquid is sprayed, the photoelectric sensor 63 always detects the liquid level in the container 62, and the elevator controls the correction of the height of the liquid level in the container 62. As a result, the difference ΔH = H ₂ −H ₁ between the height (H ₂ ) of the tip of the two-fluid spray nozzle 61 and the height (H ₁ ) of the liquid surface of the dispersion liquid is constant with an accuracy of ± 1 / 2d. (Usually H ₂ > H ₁ and d is the distance between a pair of photoelectric sensors). Therefore, even if the liquid level in the container 62 decreases, the amount of the volatile dispersion liquid 60 sucked up by the two-fluid spray nozzle 61 does not decrease, and the disposition density of the fine particles 66 on the substrate 65 does not decrease.

The second aspect of the present invention is not limited to the above configuration. For example, as the means for detecting the liquid level of the volatile dispersion liquid 60, a float sensor, an ultrasonic sensor or the like may be used in addition to the photoelectric sensor described above. A ball screw, a nut, or the like is applicable as a means for moving the container 62 up and down.

Further, in the apparatus shown in FIG. 6, the container 62 in which the volatile dispersion liquid 60 is stored is moved up and down so that the liquid level of the volatile dispersion liquid 60 and the height of the tip of the spray nozzle 61 are relative to each other. However, the same operation may be performed by supplying an amount corresponding to the consumed volatile dispersion liquid 60 into the container 62 from another supply system.

Next, the third aspect of the present invention will be described.

A third aspect of the present invention is a method of manufacturing a liquid crystal display device, which comprises a liquid crystal sandwiched between two substrates facing each other.
When the adhesive beads for spot-bonding the substrate are arranged on the substrate by a spraying method, at least a volatile dispersion liquid in which the adhesive beads are dispersed is stirred by low frequency vibration. A method for manufacturing a liquid crystal display element, which further comprises means for agitating the volatile dispersion liquid by low frequency vibration, which is used in the above manufacturing method. According to the third aspect of the present invention, the spray dispersion device is equipped with a low frequency vibration stirring system of, for example, 10 to 50 Hz, and the adhesive bead dispersion liquid is agitated to disperse the adhesive beads without agglomerating them. It is possible to keep the particle concentration in the liquid uniform.

Further, it is not necessary to put a stirring blade, a stirring bar or the like inside the liquid, and the dispersion is excellent in dust-free property.

The third aspect of the present invention will be specifically described below with reference to the drawings.

FIG. 14 is a drawing of a low-frequency vibration stirring system that best represents the third feature of the present invention. In FIG. 14, 101 is a volatile dispersion liquid in which adhesive beads are dispersed in a volatile dispersion medium, and 102. Is a Teflon tube connected to a spray nozzle for spraying the dispersion liquid 101, and 104 is a container 10.
Vibration generator (made by IMV Co., Ltd.) that gives vibration to 3
Reference numeral 05 is the oscillation amplifier. Further, on the upper part of the container 103, an acceleration pickup 106 for detecting the acceleration of vibration is provided.
Is installed, and the automatic vibration controller 107 that controls vibration
It is connected to the.

The automatic vibration controller 107 can control the vibration frequency, the displacement amount, and the acceleration.
Up to 50 Hz) and the acceleration is the adhesive bead dispersion liquid 101
Value (0.2-1.5G) sufficient to maintain uniform particle concentration
And When the acceleration value is set to a value higher than that, the dispersion liquid 101 is splashed, and the droplets adhere to the upper portion of the inner wall surface of the container, the lid of the container, and the like, which causes aggregation of the adhesive beads when dried, which is not preferable.

When the spraying is continued, the amount of the dispersion liquid decreases and the weight becomes lighter, and the acceleration of vibration increases. However, here, the acceleration is detected by the acceleration pickup 106 installed on the upper part of the container 103, Automatic vibration controller 1
Since it is fed back to 07, the acceleration is always kept constant regardless of the liquid weight.

In this way, the adhesive bead dispersion liquid is vibrated and agitated with a constant low frequency and acceleration vibration.

The third aspect of the present invention is not limited to the above-mentioned constitution. For example, by supplying the container 103 with an amount corresponding to the consumed volatile dispersion liquid 101 from another supply system, The amount of the volatile dispersion liquid 101 may be kept constant and the acceleration of vibration may be kept constant.

Next, the fourth aspect of the present invention will be described.

A fourth aspect of the present invention is a method for manufacturing a liquid crystal display device, which comprises a liquid crystal sandwiched between two substrates facing each other,
After the spacer for holding the space between the substrates and the adhesive beads for spot-bonding the substrate are disposed on the substrate, at least 2 at which the pressure load and the pressure bonding time are arbitrarily set when performing the heat pressure bonding process. A method for manufacturing a liquid crystal display device, characterized in that the pressure bonding is carried out in a step, preferably the first step is a low load and the second and subsequent steps are a high load, and the above method is also used. The apparatus for performing the above-mentioned thermocompression bonding step, further comprising means for arbitrarily setting the pressure bonding load and the pressure bonding time of the at least two stages of pressure bonding, the manufacturing apparatus for a liquid crystal display element.

According to the fourth aspect of the present invention, the thermocompression bonding step is multi-staged, and in the first pressure bonding, the two substrates are held with a low load so that the adhesive beads are not destroyed mainly for heating. In the subsequent pressure bonding, a high load is applied for the purpose of deforming the adhesive beads and approaching the distance between the two substrates, and continuous heating is performed.After that, the adhesive beads are softened without being destroyed by the curing process.・ It is deformed and melts and cures with the adhesive beads and the two substrates in contact with each other. That is,
Melt while the adhesive beads and the two substrates are in sufficient contact.
A sufficient adhesive effect can be obtained by curing.

A fifth aspect of the present invention is the method for producing a liquid crystal display element according to the first to fourth aspects of the present invention, wherein the liquid crystal sandwiched between the substrates is a ferroelectric liquid crystal. Is the way.

As the ferroelectric liquid crystal used in the fifth aspect of the present invention, those having a chiral smectic phase state can be used. Specifically, the chiral smectic C phase (SmC ^* ), H phase (SmH ^* ), I Phase (SmI ^* ),
Liquid crystals of K phase (SmK ^* ) or G phase (SmG ^* ) can be used. As a particularly preferable ferroelectric liquid crystal, a liquid crystal exhibiting a cholesteric phase on the high temperature side can be used, and for example, a pyrimidine-based mixed liquid crystal can be used.

[0048]

EXAMPLES The present invention will be described below with reference to examples.

Example 1 This example relates to the first aspect of the present invention, and FIGS. 1 and 2 show the arrangement of fine particles on a substrate in the process of manufacturing the liquid crystal display element as shown in FIG. It was performed using such a device.

First, ITO striped electrodes 32 and 3 are formed on two glass substrates 31 and 31 'having a thickness of 1.1 mm.
2 ′ is formed, and Ta ₂ O is formed thereon by a sputtering method.
₅ After forming the film 33, 33 'with a thickness of 1000 Å, L
Q1802 (Hitachi Chemical Co., Ltd., polyimide-based alignment film 34,
34 ′) was applied by a flexographic printing method, baked at a temperature of 270 ° C. for 1 hour to form a thickness of 300 Å, and then rubbed. First obtained as described above
Sealing material 35 (manufactured by Mitsui Toatsu Kagaku Co., Ltd., trade name Struct Bond XN-21-
F) was printed and put in the spray booth 6 shown in FIG. Next, as a volatile dispersion liquid 10 in which the spacers and the adhesive beads shown in FIG. 2 are dispersed, 0.1 g of spacers 36 (trade name: silica micro beads, manufactured by Catalyst Kasei) having an average particle diameter of 1.16 μm and average particles 0.8 g of adhesive beads 37 (trade name: Trepal, manufactured by Toray Industries, Inc.) having a diameter of 5.6 μm dispersed in 1 liter of isopropyl alcohol was supplied to the spray nozzle 7 through the tube 8 to form a dispersion liquid. It was sprayed. Simultaneously with the start of spraying, the spray nozzle is moved from the spraying start point 52 to the end point 53 in 70 seconds by the NC drive devices 2a and 2b shown in FIG. 1 in a pattern 51 as shown in FIG. The spacer 36 and the adhesive bead 37 were disposed on the. The first substrate 31 thus obtained is pasted with the second substrate 31 ′, and then the pair of substrates are pressure-bonded while being heated to 100 ° C., and further heat-cured at 150 ° C. for 1 hour. After that, a pyrimidine-based ferroelectric liquid crystal 38 having a phase transition temperature as shown below was injected.

[0051]

[Equation 1] A of the cell structure 30 manufactured as described above shown in FIG.
The number of spacers and adhesive beads was counted and the cell thickness was measured at 18 places of R. The number of spacers and adhesive beads per square millimeter is shown in Table 1, and the measurement result of the cell thickness is shown in Table 2.

Comparative Example 1 As Comparative Example 1, a cell structure 30 was produced in exactly the same manner as in Example 1 except that the spray nozzle 7 in the spray spraying process described in Example 1 was fixed above the center of the substrate. 1 of spacers and adhesive beads of this cell structure
The numbers per square millimeter and the cell thickness were measured in exactly the same manner as in Example 1, and the results are shown in Tables 1 and 2.

Comparative Example 2 As Comparative Example 2, the spray nozzle 7 in the spray spraying process described in Example 1 was fixed above the center of the substrate, and the distance between the spray nozzle 7 and the substrate 5 was doubled. A cell structure 30 was manufactured in exactly the same manner as in Example 1. The numbers of spacers and adhesive beads per square millimeter and the cell thickness of this cell structure were measured in exactly the same manner as in Example 1, and the results are shown in Tables 1 and 2.

[0054]

[Table 1]

[0055]

[Table 2] As shown in Table 1 and Table 2, when sprayed by the method of Example 1 according to the first aspect of the present invention, both the spacers and the adhesive beads are arranged at a substantially uniform density over the entire surface of the substrate,
A cell structure having a very uniform cell thickness over the entire surface can be obtained.

On the other hand, in the method of Comparative Example 1, the area where the spacers and the adhesive beads have a uniform density is reduced,
The cell thickness also becomes non-uniform according to the density distribution.

The method of Comparative Example 2 has a better density distribution of spacers and adhesive beads than Comparative Example 1, but is inferior to Example 1. Along with this, the cell thickness uniformity was also inferior to that of Example 1. Further, in Comparative Example 2, the adhesion efficiency of the spacers and the adhesive beads to the substrate was lowered, and the absolute value of each counted fine particle was smaller than that in Example 1. As described above, according to Comparative Example 2, as a result of improving the density distribution of the particles to be dispersed as compared with Comparative Example 1, the number of dispersed particles is reduced, and in order to obtain the same particle density as in Example 1. However, it is necessary to increase the spraying time. Further, as a result, the amount of spacers and adhesive beads used increases, leading to an increase in running cost.

Example 2 This example relates to the second aspect of the present invention, and is a step in which fine particles are dispersed in the manufacturing process of a liquid crystal display device by using an apparatus as shown in FIG.

Specifically, the allowable value of the disposition density of the adhesive beads is set to 8 from the viewpoint of imparting impact resistance and preventing deterioration of display quality.
It was defined as 0 ± 5 pieces / mm ² . Then, conventionally, since the variation width of the relative value ΔH between the height of the tip of the spray nozzle 61 and the height of the liquid surface of the volatile dispersion liquid 60 is not controlled, the spraying is performed.
When ΔH = 5 mm is initially set and the adhesive beads are sprayed 20 times, ΔH increases as the number of spraying increases as shown in FIGS. 7, 8 and 9, and the consumption amount of the dispersion liquid per one time decreases,
There was a reduction in the placement density of the adhesive beads. Here, the adhesive bead arrangement density and the impact resistance value of the panel have a relationship as shown in FIG. 10. However, when the impact resistance value of the 20 panels to which the above-mentioned adhesive beads are dispersed is examined, The panels sprayed on the 19th and 20th times were below the impact resistance standard value and were defective. On the other hand, in the system shown in FIG. 6, ΔH is 5 ± 4
When the adhesive beads were sprayed 20 times while controlling to mm,
As shown in FIGS. 11, 12, and 13, the above-mentioned phenomenon due to the increase in the number of times of spraying did not occur, and no defective product below the impact resistance standard value occurred in all 20 panels.

Example 3 This example relates to the third aspect of the present invention, in which the volatile dispersion liquid was sprayed on the substrate while stirring with a low frequency vibration using the apparatus shown in FIG. 14 in the fine particle spraying step. A liquid crystal display device was produced.

Using the spraying device shown in FIG. 14, 0.3 g of epoxy adhesive beads (trade name "Trepearl", manufactured by Toray Industries, Inc., diameter: 5.5 μm) of Freon 113 of 500 cc.
The dispersion liquid 101 dispersed in was dispersed on the first substrate on which the sealing material was formed by the screen printing method. Further, the second substrate on which SiO ₂ particles having a diameter of 2 μm are already arranged and the first substrate were bonded and pressure-bonded. FIG. 15 shows the results of measuring 46 changes in the average arrangement density of the adhesive beads for each of the 46 cells prepared above. In this 46 sets of cells, no defective substrate spacing caused by aggregation of adhesive beads was observed.

As a comparative example, the dispersion 101 was stirred by ultrasonic agitation, and the change in the density of the adhesive beads of 40 sets of cells prepared under the same conditions as in the above example was measured every 5 sets. 16 shows. In the figure, x marks are cells in which a substrate gap defect occurs due to aggregation of adhesive beads, and the x marks represent the number of defective parts.

The adhesive bead dispersion liquid is vibrated at a constant low frequency and acceleration regardless of the amount of liquid by the device shown in FIG. 14 of the third embodiment of the present invention, and uniform particles are generated without causing agglomeration of particles. Since the density can be maintained, a liquid crystal display element with a small change in arrangement density could be manufactured.

Example 4 This example relates to the fourth aspect of the present invention, in which a two-step thermocompression bonding process is performed in the manufacturing process of the liquid crystal display element.

FIG. 17 is a diagram for explaining the thermocompression bonding process of this embodiment. In the figure, 37 is an adhesive bead,
36 is a spacer material, and 31 and 31 'are substrates. First, the substrates 31 and 31 ′ on which the adhesive beads 37 and the spacer material 36 are dispersedly arranged (for example, adhesive beads: 80 pieces / mm ² , spacer material: 300 pieces / mm ² ) are bonded (FIG. 17A). Refer to) 1st step crimping at 70 ℃,
Adhesive beads 3 at 0.7 kgf / cm ² for 5 minutes
7 softens. Next, press the second step to 70 ° C, 3kgf /
Perform for 2 minutes at cm ² . Then, the two substrates 31, 31 '
Comes close to the diameter (φd) of the spacer material 36, and the adhesive bead 37 is crushed and deformed without scattering or breaking to become 37a (see FIG. 17B). After that, cure the adhesive beads and sealing material at 170 ℃ and 1.2kg.
When performed at f / cm ² for 30 minutes, the adhesive beads 37a are melted and hardened while maintaining the substrate distance d, and the adhesive beads 37
b, and the two substrates 31, 31 'are spot-bonded (see FIG. 17).
(See (c)). After the curing process is completed, a panel in which two substrates are spot-bonded and a gap of d is not filled with liquid crystal is obtained.

As a comparative example, a conventional thermocompression bonding process is shown in FIG.
This will be described using 8.

First, as in the case of FIG. 17, the substrates 31 and 31 'are attached (see FIG. 18 (a)), and pressure bonding is performed at 70 ° C. and 3 kg.
Perform at f / cm ² for 5 minutes. At this time, the adhesive beads 3
Since 7 is pressure-bonded under a high load without being sufficiently heated and softened, the adhesive beads 37 are broken and scattered to become 37c (see FIG. 18 (b)). Then, the adhesive beads 37d are melted and cured (see FIG. 18C), and the two substrates 3
1,31 'cannot be adhered sufficiently.

The panel manufactured in the present example according to the fourth aspect of the present invention and the panel manufactured by the conventional method as a comparative example were cut into 35 mm square, and the adhesive strength (represented by shear strength) and the adhesive beads were used. When the arrangement density of was measured, the results shown in Table 3 were obtained.

[0069]

[Table 3] Further, when the state of the adhesive beads between the substrates after the measurement of the adhesive strength is observed with an electron microscope, it is as shown in FIG. 19 (a) (the fourth embodiment of the present invention) and FIG. 19 (b) (conventional example). there were. From the above results, it can be seen that the bonding effect between the two substrates is obviously increased by carrying out the fourth embodiment of the present invention.

FIG. 20 shows a thermocompression bonding apparatus used in this embodiment according to the fourth aspect of the present invention. In the figure, 201 is an upper mold, 202 is a lower mold, 203 is a servo motor, 204 is a load cell, 205 is a ball screw, 206 is a heater,
Reference numeral 207 is a control unit of the servomotor 203, 208 is a setting unit for the pressure bonding time (T ₁ , T ₂ ), pressure bonding load (W ₁ , W ₂ ), and 209 is a control unit for the heater 206 and a temperature (t) setting unit. is there.

The axis of the servo motor 203 is the ball screw 2
05, the servomotor 203 is driven to rotate the ball screw 205, and the vertical movement of the lower mold 202 and the pressure-bonding load are obtained. Load cell 204
The output of is set to zero when the pressure is not applied and is sent to the control unit 207 of the servomotor 203. Servo motor 2
03 is feedback-controlled based on this signal so as to generate a crimping load W ₁ or W ₂ .

When the temperature (t), the crimping time (T ₁ , T ₂ ) and the crimping load (W ₁ , W ₂ ) are set and the crimping operation is started, the lower mold 202 is raised. As shown in FIG. 21, when the crimping load W reaches W ₁ , a timer for T ₁ time is activated, and during that time, the servo motor 203 is feedback-controlled so as to maintain W ₁ .

Next, when the timer for T ₁ hours expires, the pressure shifts to W = W ₂ and T = T ₂ , and when the timer for T ₂ hours expires, the lower mold 202 descends and the pressure bonding operation ends. ..

In this apparatus, the substrate temperature (t) and the pressure bonding time (T ₁ , T
₂ ) By appropriately setting the crimping load (W ₁ , W ₂ ), a desired adhesive strength can be obtained.

The fourth aspect of the present invention is not limited to this embodiment, and the pressure bonding time / pressure bonding load chart as shown in FIG. 21 may be arbitrarily set to set the pressure bonding process in multiple stages. Further, the device configuration is not limited to the configuration shown in FIG. 20, and any device capable of controlling the above-mentioned pressure bonding conditions may be used.

[0076]

As described above, the present invention has the following effects. (1) According to the first liquid crystal display element manufacturing method of the present invention,
By moving the spacer and / or the spray nozzle for spraying the adhesive beads in the spray spraying process above the substrate during the spray spraying, even if the distance between the substrate and the spray nozzle is reduced, the density distribution of the spray particles is kept uniform. Moreover, the spraying time can be shortened, and as a result, spacers and adhesive beads can be saved. Furthermore, by moving the spray nozzle, without increasing the size of the device,
It can be used for larger substrates. (2) According to the second method and apparatus for manufacturing a liquid crystal display element of the present invention, the difference ΔH between the height of the tip of the two-fluid spray nozzle and the height of the liquid surface of the volatile dispersion liquid is always constant or substantially constant. By controlling, the amount of the volatile dispersion liquid sucked up by the two-fluid spray nozzle and sprayed per spray is always constant or substantially constant, and the disposition density of fine particles decreases with the increase in the number of sprays. In particular, in the case of the ferroelectric liquid crystal display element, it is possible to prevent the impact resistance of the liquid crystal display element from being lowered due to the reduction in the density of the adhesive beads. (3) According to the third method and apparatus for manufacturing a liquid crystal display element of the present invention, when the adhesive beads are arranged on the substrate by the spraying method, the volatile dispersion liquid is vibrated by low frequency vibration. By stirring, (a) prevention of aggregation of adhesive beads (b) prevention of change in particle concentration in liquid due to adhesion of adhesive beads to container inner wall surface (c) uniform concentration of adhesive bead particles in dispersion liquid It is possible to manufacture an element which can be held at a low temperature and whose density change of the adhesive beads is small. (4) According to the fourth method and apparatus for manufacturing a liquid crystal display device of the present invention, the thermocompression bonding step of the substrate on which the adhesive beads and the spacer material are dispersed is multistaged to perform the thermocompression bonding of the first step. For the main purpose of heating, the adhesive beads and the two substrates are separated by holding the two substrates bonded together under a low load so that the adhesive beads do not break and performing high-pressure thermocompression bonding after the second stage. Since it melts and cures in a state of being in wide contact, it is possible to obtain a large adhesive effect between the two substrates.

[Brief description of drawings]

FIG. 1 is a plan view schematically showing a configuration example of a moving device for a spray spraying nozzle according to the first aspect of the present invention.

FIG. 2 is a schematic diagram showing a spray nozzle attached to the moving device shown in FIG.
FIG. 3 is a side view schematically showing how fine particles are dispersed on a substrate.

FIG. 3 is a cross-sectional view showing an example of a ferroelectric liquid crystal display device manufactured according to the first aspect of the present invention.

FIG. 4 is a diagram showing measurement points of the number of fine particles and the cell thickness of the ferroelectric liquid crystal display device manufactured according to the first aspect of the present invention.

FIG. 5 shows an example of a movement pattern of the spray-spraying nozzle according to the first aspect of the present invention.

FIG. 6 is a diagram schematically showing an example of a second liquid crystal display device manufacturing apparatus according to the present invention.

FIG. 7 is a graph showing the relationship between the number of times of application and ΔH in the conventional example.

FIG. 8 is a graph showing the relationship between the number of times of spraying and the amount of dispersion liquid consumed for spraying per time in the conventional example.

FIG. 9 is a graph showing the relationship between the number of times of spraying and the adhesive bead arrangement density in a conventional example.

FIG. 10 is a graph showing the relationship between the distribution density of adhesive beads and the impact resistance value of the panel.

FIG. 11 is a graph showing the relationship between the number of times of application and ΔH in the second aspect of the present invention.

FIG. 12 is a graph showing the relationship between the number of times of spraying and the amount of the dispersion liquid consumed for spraying once in the second aspect of the present invention.

FIG. 13 is a graph showing the relationship between the number of times of spraying and the adhesive bead arrangement density in the second aspect of the present invention.

FIG. 14 is a diagram schematically showing an example of an apparatus for manufacturing a liquid crystal display element according to the third aspect of the present invention.

FIG. 15 is a graph showing the average arrangement density of adhesive beads of 46 sets of cells produced in Example 3 according to the present invention.

FIG. 16 is a graph showing an average arrangement density of adhesive beads of 40 sets of cells produced by a conventional method.

FIG. 17 is a diagram for explaining a thermocompression bonding process according to the fourth aspect of the present invention.

FIG. 18 is a diagram for explaining a thermocompression bonding process in a conventional example.

FIG. 19 is a diagram showing an image of an adhesive bead between substrates according to the fourth and conventional methods of the present invention, observed with an electron microscope.

FIG. 20 is a diagram schematically showing an example of an apparatus for manufacturing a liquid crystal display element according to the fourth aspect of the present invention.

FIG. 21 is an example of a pressure bonding time / pressure bonding load chart according to the fourth aspect of the present invention.

[Explanation of symbols]

 1 Spray Nozzle Attachment Axis 2a, 2b X, Y Direction NC Drive Device 3 Fixed Axis 4 Stage 5 Substrate 6 Booth 7 Spray Nozzle 8 Tube 9 Container 10 Solution 11 Ultrasonic Generator 12 Mount 13 Conical Spray Liquid Cross Section 30 Cell Structure 31, 31 'Substrate 32, 32' Transparent electrode group 33, 33 'Insulating film 34, 34' Alignment film 35 Sealing material 36 Spacer 37, 37a-d Adhesive beads 38 Ferroelectric liquid crystal 51 Spray nozzle movement pattern 52 Spraying start point 53 Spraying end point 60 Volatile dispersion liquid 61 Spray nozzle 62 Container 63 Photoelectric sensor 64 Elevator drive unit 65 Substrate 66 Fine particles 67, 68 Piping 69 Elevator control unit 70 Mass flow controller 101 Volatile dispersion liquid 102 Teflon tube 103 container 104 vibration Machine 105 oscillation amplifier 106 accelerometer 107 automatic vibration controller 201 upper die 202 lower mold 203 servomotor 204 load cell 205 ball screw 206 heater 207 servo motor control unit 208 crimped condition setting unit 209 control unit and setting unit heater

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kimio Takahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (11)

[Claims] 1. A method for manufacturing a liquid crystal display device, comprising a liquid crystal sandwiched between two substrates facing each other, wherein a spacer for holding a space between the substrates and / or an adhesive bead for spot-bonding the substrates is sprayed. According to the method for producing a liquid crystal display element, the spray spraying nozzle moves above the substrate when it is arranged on the substrate. 2. The method of manufacturing a liquid crystal display device according to claim 1, wherein the spray-dispersing nozzle moves in a plane parallel to the substrate surface. 3. The movement of the spraying nozzle is controlled by NC.
The method for manufacturing a liquid crystal display element according to claim 1, wherein the method is performed by driving. 4. A method of manufacturing a liquid crystal display device, which comprises a liquid crystal sandwiched between two substrates facing each other, and a spacer for holding a space between the substrates and / or an adhesive bead for spot-adhering the substrates is incorporated. In the fine particle spraying step of spraying with a two-fluid spray nozzle that is a suction system and disposing on the substrate, the spacer and or the height of the liquid surface of the volatile dispersion liquid in which the adhesive beads are dispersed, A method for manufacturing a liquid crystal display device, characterized in that the height of the tip of the spraying nozzle is controlled to be relatively constant or substantially constant. 5. The liquid crystal display device according to claim 4, wherein the device for performing the fine particle spraying step has means for controlling the height of the liquid surface of the volatile dispersion liquid. Display device manufacturing equipment. 6. A method of manufacturing a liquid crystal display device comprising a liquid crystal sandwiched between two substrates facing each other, wherein adhesive beads for point-bonding the substrates are arranged on the substrates by a spray dispersion method. A method for manufacturing a liquid crystal display device, characterized in that a volatile dispersion liquid in which at least the adhesive beads are dispersed is stirred by low-frequency vibration. 7. A liquid crystal display device manufacturing apparatus used in the method of manufacturing a liquid crystal display device according to claim 6, further comprising means for stirring the volatile dispersion liquid by low frequency vibration. Liquid crystal display device manufacturing equipment. 8. A method of manufacturing a liquid crystal display device comprising a liquid crystal sandwiched between two substrates facing each other, wherein spacers for holding a space between the substrates and adhesive beads for point-bonding the substrates are provided on the substrate. A method for manufacturing a liquid crystal display element, comprising performing at least two stages of crimping with a crimping load and a crimping time arbitrarily set when the thermocompression bonding step is performed after the disposition. 9. The method of manufacturing a liquid crystal display device according to claim 8, wherein in the thermocompression bonding step, the first-stage pressure bonding load is set to a low load and the second-stage and subsequent pressure bonding loads are set to a high load. . 10. The apparatus for performing the thermocompression bonding process of the method for manufacturing a liquid crystal display element according to claim 8 or 9, further comprising means for arbitrarily setting a pressure bonding load and a pressure bonding time of the at least two stages of pressure bonding. An apparatus for manufacturing a liquid crystal display element, which is characterized by: 11. The method of manufacturing a liquid crystal display device according to claim 1, wherein the liquid crystal is a ferroelectric liquid crystal.