JPH09138417A - Production of liquid crystal cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to produce liquid crystal cells with which the infiltration of moisture and foreign matter into the cells at the time of cutting substrates by a dicing saw or CO2 laser is prevented and which has high reliability even if the substrates are glass substrate as thick as >=2mm. SOLUTION: One of a pair of the glass substrates 29 is provided with first sealant 31 into which spacers for forming a prescribed gap are incorporated between the glass substrates to each other along the outer peripheral edges of the glass substrate 29. The surface of the glass substrate 29 on the inner side of the first sealants 31 is provided with second sealants 33 provided with liquid crystal sealing regions 33a. The substrates are superposed on each other in the state of disposing the surfaces provided with the sealants 31, 33 opposite to the other glass substrate and the substrates are press bonded to each other. The outside surfaces of the respective glass substrates of the periphery of the second sealants 33 are provided with notches to the extent that the substrates are not parted; thereafter, the respective glass substrates are washed and are cut in the notched parts, by which the liquid crystal cells for each of the second sealants 33 are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a liquid crystal cell, which is formed by sealing a liquid crystal between a pair of translucent substrates arranged so as to face each other.

[0002]

2. Description of the Related Art Fabry-Perot, one of liquid crystal cells
The etalon has a structure in which a pair of translucent substrates having a reflective film on the inner surface are arranged and stacked at a constant interval, and when light is incident on this, it is incident on the reflective films on both substrates. Light is repeatedly reflected, and only specific wavelengths in phase are selectively transmitted through this etalon.

The transmission wavelength λ is represented by λ = 2nd / m.

Here, n is the refractive index of the substance arranged between the light-transmitting substrates, d is the distance between the light-transmitting substrates, m is the order of reflection, and a transparent electrode is provided on the pair of light-transmitting substrates in the etalon. When the liquid crystal is sealed between the optical substrates, the refractive index can be changed by controlling the voltage due to the birefringence of the liquid crystal, and the wavelength of light transmitted through the etalon can be selected by the voltage.

FIG. 7 is a sectional view showing the structure of a liquid crystal etalon. In this liquid crystal etalon, non-reflective films 5 and 7 are formed on the outside of two glass substrates 1 and 3 which are transparent and transparent substrates which are arranged to face each other, while a transparent electrode 9 is formed on the inside. 11, the reflective films 13 and 15, and the alignment films 17 and 19 in which the long axes of liquid crystal molecules are aligned in parallel to the glass substrates 1 and 3, are sequentially formed, and a liquid crystal 21 is formed between the formed glass substrates 1 and 3. It is enclosed. Liquid crystal 21 and alignment films 17 and 19
The outer peripheral portion of is sealed with a sealant 23, and a spacer 25 for maintaining a constant distance between the glass substrates 1 and 3 is provided in the sealant 23.

In the production of such a liquid crystal etalon, a plurality of cells are simultaneously obtained from a pair of glass substrates in order to reduce the production cost. As a production method, a liquid crystal cell is used as a liquid crystal etalon. The procedure is similar to that of liquid crystal display panel (LCD) that does not require a reflective film. Here, the manufacturing process after the process of forming the sealing agent after the film formation will be described. First, the reflection films 13 and 1
For each of a plurality of cells to be obtained, a sealant 23 such as a one-component epoxy system in which a glass fiber spacer 25 for gap formation is mixed with any one of the glass substrates 1 and 3 with 5 Printing is performed (usually arranged in a matrix), and pressure is uniformly applied to the whole in a state where the two sheets are stacked. Then, after the sealing agent 23 is cured, a plurality of liquid crystal cells are secured by cutting the substrate surface with a diamond cutter or the like and then dividing, so that a plurality of liquid crystal cells are secured, and liquid crystal is injected into each liquid crystal cell.・ Complete by sealing.

Further, Japanese Patent Laid-Open No. 4-199130 discloses a technique in which the above-mentioned liquid crystal cell is manufactured using a vacuum container. The work procedure according to this manufacturing method is shown in FIG. FIG. 9 is a plan view of one of the glass substrates in a state in which a sealant mixed with a spacer for forming a gap is printed. The sealant 26 for liquid crystal encapsulation includes a liquid crystal encapsulation region 26a and a liquid crystal injection port 26b.
A sealing agent 28 for sealing is formed on the outer periphery of the glass substrate 27 along the periphery of the glass substrate 27.

After the sticker printing, the one glass substrate 2 described above is printed.
A block is arranged between the glass substrate 7 and the other glass substrate (not shown) on the outer peripheral side of the sealing agent 28 for sealing, so that a space is provided between the pair of glass substrates, and both glass substrates are superposed in this state. . Thereafter, with respect to the laminated glass substrates, the blocks are removed in a vacuum container to bond the two glass substrates to each other, and the inside of the vacuum container is brought to the atmospheric pressure state, whereby the inside of the sealing seal 28 is vacuumed. Since both glass substrates are maintained at the atmospheric pressure, the two glass substrates are pressed against each other by the atmospheric pressure, and are pressure-bonded via the sealant.

After that, the liquid crystal encapsulating sealant 26 and the hermetic sealant 28 are hardened in a heating oven or the like, and the outer peripheral side of the liquid crystal encapsulating sealant 26 is cut by a scribe-break method. After the liquid crystal cell of (1) is created, liquid crystal is injected into each liquid crystal cell from the liquid crystal injection port 26b of the liquid crystal encapsulating sealant 26 to seal the liquid crystal cell.

[0010]

By the way, in a glass substrate having a thickness of 1.1 mm or less, which is generally used in a liquid crystal cell, the glass substrate may be deformed at the time of pressure bonding or liquid crystal encapsulation, and a uniform gap cannot be secured. Many. The glass substrate does not deform, and a thickness of 2 mm or more is required to maintain high surface accuracy. For a glass substrate with such a thickness, the conventional manufacturing method described above is used. It was not possible to cut by the scribe-break method that was used, and it was not possible to manufacture a cell for liquid crystal injection.

As a method of cutting a glass substrate having a thickness of 2 mm or more, a dicing saw having a blade at the tip of a spindle rotating at a high speed or a method using a carbon dioxide gas laser can be used. However, in the dicing saw, since water for cooling the blade is used, water invades the cell, and in the carbon dioxide laser, glass powder generated at the time of cutting similarly invades the cell, The problem occurs.

Therefore, the object of the present invention is to enable the production of a highly reliable liquid crystal cell capable of preventing the infiltration of water and foreign matter into the cell even when the substrate is cut, even with a thick glass substrate. There is.

[0013]

In order to achieve the above-mentioned object, the present invention provides a pair of translucent substrates, which form a gap having a predetermined size therebetween, on the mating surfaces of the translucent substrates. A first sealant having an adhesive function along the outer peripheral edge portion and a second sealant having an adhesive function to form a liquid crystal enclosing region in which liquid crystal is enclosed inside the first sealant, respectively. Each of the first and second sealing agents is superposed on each other so that the first and second sealing agents are sandwiched between a pair of translucent substrates, and fixed by pressure. A cut is made on the outer surface of the transparent substrate so that the transparent substrate is not divided, and then each transparent substrate is cut off at the cut portion, and is cut into the liquid crystal enclosing region surrounded by the second sealant. This is a manufacturing method of enclosing a liquid crystal.

When the first sealant is provided on the translucent substrate, a part of the entire circumference forms an opening that allows the inside and the outside to communicate with each other, and in this state, the translucent substrate. This is a manufacturing method in which the openings are sealed with a sealant after they are pressure-bonded and fixed to each other.

According to such a method of manufacturing a liquid crystal cell,
The translucent substrate is cut by making a notch on the outer surface of each translucent substrate around the second sealant to such an extent that the substrate is not divided, and then washing and cutting each translucent substrate at the notch. Since it is separated, even if the substrate is thick, it is possible to avoid the infiltration of water or foreign matter into the cell at the time of cutting.

Further, since the opening is formed in the first sealant on the outer peripheral side, when the pair of translucent substrates are superposed on each other and pressure-bonded, the inside of the first sealant is surrounded by the first sealant. Air can be appropriately discharged to the outside, and a more uniform gap can be formed.

[0017]

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

One embodiment of the present invention relates to the production of a liquid crystal etalon as a liquid crystal cell, and a glass substrate as a translucent substrate used for the same has a surface precision that is optically polished to obtain a uniform gap. A quartz or borosilicate glass having a high thickness of 2 mm or more is used. The transparent electrode film (ITO: a compound of indium oxide and tin oxide) and a reflective film are provided on the surfaces of the glass substrate facing each other, as in the conventional one shown in FIG. The respective prevention films are laminated and formed by a vacuum vapor deposition method or the like, an alignment film such as polyimide is applied on the reflection film, and an alignment treatment is performed by a rubbing method or the like.

FIGS. 1 and 2 show a sealant formed on the surface of one glass substrate 29 facing the other glass substrate, which is the mutual mating surface of the pair of glass substrates described above. The sealant is a first sealant 31 formed along the outer peripheral edge of the glass substrate 29, and a liquid crystal encapsulation in which liquid crystal is encapsulated on the one glass substrate 29 inside the first sealant 31. A plurality of (two in FIG. 2) second sealants 3 arranged in a matrix to form the region 33a.
3 is provided. Each of the sealants 31 and 33 is made of a one-component epoxy system or the like in which glass fiber spacers for securing a gap between a pair of glass substrates are mixed.

The first sealant 31 is disposed opposite to each other 2
The inside and outside surrounded by the first sealant 31 communicate with the corner portions (upper left and lower right in FIG. 1) or the four corner portions (FIG. 2) to form a pair of glasses. An opening 35 is formed for discharging the internal air to the outside when the substrates are pressure-bonded to each other. On the other hand, the second sealant 33
Has a liquid crystal injection port 33b for injecting liquid crystal into the liquid crystal enclosing region 33a.

FIG. 3 shows a manufacturing process of the liquid crystal etalon including the printing of the respective sealing agents 31 and 33. After printing the sealants 31 and 33, as shown in FIG. 4 corresponding to the example of FIG. 2, a pair of glass substrates 29 and 37 are superposed on each other, and a press machine or the like generally used for manufacturing a liquid crystal panel is used. Then, the two substrates 29 and 37 are bonded to each other by pressure-bonding with each other and heat-cured to form a gap G between the two substrates 29 and 37. During the crimping operation, the air inside the first sealant 31 is appropriately discharged to the outside through the two openings 35 in the example of FIG. 1, thereby forming a uniform gap G as a whole. To be done. When the openings 35 are provided in the four corner portions as in the example of FIG. 2, air is discharged more appropriately,
This is effective in forming a uniform gap G.

After the sealing agents 31 and 33 are cured, a cyanoarylate-based instant adhesive, a UV curing type adhesive, or each sealing agent 31, 33 is applied to the opening 35.
The same adhesive and the like are permeated from the end surface of the glass substrate to cure and seal.

Next, in order to obtain a liquid crystal cell formed for each second sealant 33, the glass substrate is cut with a dicing saw or a carbon dioxide gas laser. In this cutting operation, as shown in FIG. 5, a cut is made from the outer surface of each glass substrate 29, 37 around the second sealant 33 to the extent that the glass substrates 29, 37 are not cut in the thickness direction. Insert 29a and 37a respectively. FIG. 6 is a plan view of FIG. 5 with the notches 29a and 37a. The preferable depth of cut of each of the cuts 29a and 37a is about ½ of the substrate thickness (half cut).

Since the glass substrates 29 and 37 are not divided but only the cuts 29a and 37a are made, the cooling water of the blade when using the dicing saw and the glass powder when using the carbon dioxide laser are used. It is possible to avoid the invasion of the liquid crystal into the liquid crystal enclosing region 33a surrounded by the second sealant 33.

The glass substrates 29 and 37 having the cuts 29a and 37a are washed and dried in order to remove water and foreign substances adhering to the surface during the half-cutting work. Then, the glass substrates 29 and 37 are pressed against the glass substrates 29 and 37 with a roller or a squeegee to cut along the cuts 29a and 37a.
A liquid crystal cell having a shape in which the second sealant 33 has a substantially outer shape can be obtained. That is, nine liquid crystal cells are obtained in FIG. 1 and two liquid crystal cells are obtained in FIG. A liquid crystal etalon having a uniform gap is completed by injecting liquid crystal into the liquid crystal cell through the liquid crystal injection port 33b and sealing the liquid crystal cell.

The above-mentioned division by the roller is performed by using a device equipped with a stage having a rubber sheet on its upper surface and a rubber roll capable of rotating at a constant interval with respect to the upper surface of the stage. By moving the stage together with the glass substrates 29 and 37 in a state where the glass substrates 29 and 37 are placed, the glass substrates 29 and 37 are pressed between the rubber sheet and the rubber roll and pressure is applied, whereby the rubber The cut on the sheet side (for example, the cut 29a when the glass substrate 29 is on the lower side) is continuously divided at several places. Notch 3 on the glass substrate 37 side
In order to divide 7a, the glass substrate 37 is placed on a rubber sheet with the glass substrate 37 turned upside down, and the same work as above is performed.

On the other hand, the cutting with the squeegee uses a rubber squeegee whose tip has an angle of approximately 90 degrees instead of the rubber roll by the above-mentioned roller cutting, and the glass substrate placed on the rubber sheet on the stage as described above. With respect to 29 and 37, the tip of the rubber squeegee is pushed into the notch 37a of the glass substrate 37 while the glass substrate 29 is on the lower side to apply pressure, and the notch 29a on the rubber sheet side corresponding to the portion to which this pressure is applied is 1 It is divided into places. In order to cut the cut 37a of the glass substrate 37, the glass substrate 37 is placed on a rubber sheet with the glass substrate 37 turned upside down, and the same work as above is performed.

According to the method for manufacturing a liquid crystal cell as described above, even when a glass substrate having a thickness of 2 mm or more and high surface accuracy can be secured, when the glass substrates 29 and 37 are cut using a dicing saw or a carbon dioxide gas laser. In addition, it is possible to prevent water and foreign matter from entering the cell, and it is possible to manufacture a highly reliable liquid crystal cell.

Although a liquid crystal etalon has been described as a liquid crystal cell in the above embodiment, the present invention can be applied to the manufacture of a liquid crystal display panel.

[0030]

As described above, according to the present invention, the translucent substrate is cut by cutting the outer surface of each translucent substrate around the second sealant to the extent that the substrate is not divided. Since each translucent substrate is cut off at the cut portion after cleaning after inserting, even if it is a thick translucent substrate, infiltration of moisture and foreign matter into the cell at the time of cutting is avoided, and reliability is improved. It is possible to manufacture high-quality liquid crystal cells.

Further, since the opening is formed in the first sealant on the outer peripheral side, when the pair of translucent substrates are superposed and pressure-bonded, the inside of the first sealant is surrounded by the first sealant. Air can be appropriately discharged to the outside, and a more uniform gap can be formed.

[Brief description of the drawings]

FIG. 1 is a plan view showing a sealing agent printing surface of a glass substrate showing an embodiment of the present invention.

FIG. 2 is a plan view showing another example of the glass substrate.

FIG. 3 is a manufacturing process diagram of a method of manufacturing a liquid crystal cell according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a state in which a pair of glass substrates are pressure-bonded to each other in the manufacturing process of FIG.

5 is a cross-sectional view showing a state in which a cut is made in the glass substrate after the pressure bonding of FIG.

FIG. 6 is a plan view of FIG. 5;

FIG. 7 is a cross-sectional view showing a structure of a general liquid crystal etalon.

FIG. 8 is a manufacturing process diagram of a conventional method for manufacturing a liquid crystal cell.

9 is a plan view showing a sealant printing surface of the glass substrate according to the manufacturing method of FIG.

[Explanation of symbols]

 29,37 Glass substrate (translucent substrate) 29a, 37a Notch 31 First sealant 33 Second sealant 33a Liquid crystal enclosing region 35 Opening G Gap

Claims (2)

[Claims] 1. A first sealant having a bonding function along the outer peripheral edge of the transparent substrate, on a mating surface of a pair of transparent substrates forming a gap having a predetermined size therebetween. A second sealant having an adhesive function for forming a liquid crystal encapsulation region in which liquid crystal is encapsulated is provided inside the first sealant, and the first and second sealants are paired with a pair of transparent members. The translucent substrates are superposed on each other so as to be sandwiched by the translucent substrates and fixed by pressure, and a cut is made on the outer surface of each translucent substrate around the second sealant to such an extent that the translucent substrates are not divided. A method for manufacturing a liquid crystal cell, characterized in that the liquid crystal substrate is then washed and separated from each of the translucent substrates at the cut portion, and liquid crystal is sealed in the liquid crystal sealed region surrounded by the second sealant. 2. When the first sealant is provided on a transparent substrate, a part of the entire circumference forms an opening that allows the inside and the outside to communicate with each other. The method for producing a liquid crystal cell according to claim 1, wherein the opening is sealed with a sealant after the pressure-sensitive adhesive is fixed by pressure.