JPS6296925A - Manufacture of liquid crystal sealing cell - Google Patents

Abstract

PURPOSE:To adjust intervals of spacers freely and finely by forming an adhesive layer consisting of a photosensitive resin at least on the surface of one of the first and second panels in approximately uniform minute patterns. CONSTITUTION:Transparent picture element electrodes 4 or segment electrodes are formed on a transparent substrate 3 and an oriented film 5 is formed on picture element electrodes 4 to produce the first panel A', and transparent counter electrodes 8 or a common electrode is formed on a transparent substrate 9 and an insulating film 13 is formed on counter electrodes 8 as occassion sequires to produce the second panel B'. An adhesive layer 14 consisting of a photosensitive resin is formed approximately uniformly in minute patterns on all of the surface of the first panel A' or the second panel B'. The first panel A' and the second panel B' are allowed to face each other and are heated simultaneously with pressuring to join the first panel A' and the second panel B', thus producing a liquid crystal sealing cell.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device.

The present invention relates to a method for manufacturing a cell for encapsulating a liquid crystal, which is suitable for encapsulating a ferroelectric liquid crystal.

(Prior Art) FIG. 6 shows an example of a transmission type liquid crystal display device using a twisted nematic stick (hereinafter abbreviated as TN) type liquid crystal. The light source (1) is a three-wavelength fluorescent light, natural light, etc.
), the light exits the polarizer (2) and the transparent substrate (3).

1jli elementary electrode (4) or segment electrode, alignment film (5), liquid crystal (6), alignment film (force, counter electrode (8) or common electrode.

It passes through a transparent substrate (9) and an analyzer l1O). LCD (6
) are kept at constant intervals by spacers Uυ, and the sealing material α2
protected from the outside air. Pixel electrode (4) and counter electrode 11f
When a voltage is applied between i and (8), it operates as a display device. The thickness of the liquid crystal (6) is 5 μm to 10 μm for conventional TN type liquid crystal and guest host (hereinafter abbreviated as GH) type liquid crystal.
The thickness of the liquid crystal (6), that is, the electrode gap was regulated by a spacer. Conventionally, the spacer (11) has only been used by appropriately scattering glass fibers, glass beads, resin beads, etc., and has not joined the first panel holder and the second panel CB).

The sealing material (12) is responsible for the bonding of the first panel and the second panel CB+, and the sealing material (1z is a silk screen etc. After printing with adhesive, the two panels were pressed together and heated to harden.

(Problems to be solved by the invention) In recent years, the characteristics of ferroelectric liquid crystals (ferro-liquid crystals) have become clear, and their outstanding characteristics such as responsiveness, contrast memory effect, wide viewing angle, etc. have attracted attention.1 Development into display devices is being considered from many angles. In order to exhibit the characteristics of ferro-liquid crystal, it is preferable to maintain the II gap in the liquid crystal filling cell to be sufficiently narrow over the entire cell area, that is, to 2 μm or less, preferably 1 μm or less.

However, it is not only difficult to process the above-mentioned glass fibers, glass beads, and resin beads with high accuracy of 2 μm or less, but also there is contamination by dust during the spraying process, etc., and the electrode gap is reduced to 2 μm. It was difficult to keep it below. Furthermore, it was extremely difficult to uniformly print the sealing materials 1'' and 21 to a thickness of 2 μm or less.

(Structure of the Invention) A method for manufacturing a liquid crystal filling cell according to the present invention will be described with reference to the drawings.

As shown in FIG. 1, a first panel structure includes a transparent pixel electrode (4) or segment electrode formed on a transparent substrate (3), and an alignment film (5) formed on the pixel electrode (4). ', and a second panel (B) in which a transparent counter electrode (8) or a common electrode is formed on a transparent substrate (9), and an insulating film (■3) is formed on the counter electrode (8) as necessary. )'.

The first panel w' or as shown in FIG.

and the second panel [3) v) An adhesive layer made of photosensitive resin; 141 is formed in a fine pattern on the entire surface with a substantially average pattern. The first panel 8' and the second panel (B)' are facing each other.

By applying pressure and heating at the same time, as shown in FIG. 3, the first panel holder' and the second panel (B)'tf are joined to produce a liquid crystal filling cell.

In addition, if necessary, as shown in FIG. 4, before forming a rigid auxiliary spacer (1141) with the same thickness as the adhesive layer 1141 near the adhesive layer 1141, as shown in FIG. Alternatively, after forming the first panel A' and the second panel (B)', the first panel A' and the second panel (B)' are heated under pressure to manufacture a liquid crystal filling cell.

The transparent substrate (3) and transparent substrate (9) have a thickness of 0°5rrr.
The ability of a glass substrate of M to 5 to obtain good results is not limited to this value.

As for the glass substrate, optically polished alkali-free metal glass is preferable, but silicon monoxide? Coated blue plate glass may also be used. The pixel electrode (4) and the counter electrode (8) are made of tin oxide, 4. A film of indium chloride or a mixture thereof (ITO) was formed to a thickness of approximately 0.05 μm by sputter deposition, and then exposed and developed.
The pattern can be processed into any shape using the image. For the alignment film (5), poval polyimide or the like is applied to a thickness of about 1 μm using offset printing or a spin coater, and after drying, it is patterned as necessary and rubbed. Further, the alignment film (5) is formed at an angle of 0.2 μm to 0.5 μm at 5102. The insulating film (13) improves the voltage resistance and the orientation of the ferro liquid crystal. The adhesive layer (2) is preferably a photosensitive resin, such as a rubber-based resist, more specifically an isoprene-based cyclized rubber or a butadiene-based cyclized rubber, which is evenly distributed over the entire display surface as shown in Figure 2 (c). do. The adhesive layer■
The film thickness is 2 μm or less, preferably 1 μm or less. The shape of the adhesive layer 1141 may be either dots or lines, and the size is preferably wide enough without deteriorating the display effect. hand.

It can also serve as a light shielding layer. To specifically describe the method for forming the adhesive layer (141), the alignment film (5) of the first panel
) or on the counter electrode (8) of the second panel or on the insulating fiQ31 formed as necessary, apply a rubber resist with a spinner, dry it, expose a pattern of arbitrary shape, and then develop it according to a conventional method. to represent. Next, the first panel holder' and the second panel (B)' are made to face each other, and while applying pressure uniformly to the entire surface of the panel, the softening temperature of the rubber resist is set to 140°C.
After heating to 160°C to 160°C, the mixture is further maintained at a temperature higher than the cyclization starting temperature, for example 180°C or higher, for a certain period of time, cooled, and then the pressurized state is released. With the above process, the $1 panel ' and the second panel CB)' (7) touch at the same position! I-[4
1 and then bonded after alignment, the contact strength is further strengthened.

As shown in FIG. 4, by forming an auxiliary spacer I' having the same thickness near the adhesive Ifji IJ41.

It can prevent the adhesive layer (141) from spreading during pressurization and separate heating of the first panel (A)' and the second panel'. In particular, the flatness of the transparent substrate (3) and the transparent substrate (9) is poor. In this state, even when pressure is applied uniformly, a local pressure difference occurs, and the adhesive layer tends to spread in areas where the pressure is concentrated. The pressurizing pressure can prevent the spread of o, s kg/i to 5 kg/c
A range of l is appropriate. As shown in FIG. 2(c), the area occupied by the adhesive layer α is preferably about 5% so as not to reduce the aperture ratio of the display device. In this case, the pressure applied to the adhesive layer α reaches 20 times the pressure applied above. Also, the size of the transparent substrate (3) and the transparent substrate (9).

The required pressure varies depending on the thickness and flatness. Particularly in the case of a transparent substrate with good flatness, excellent results can be obtained with an extremely small pressure of 1, for example, 0, s kg/cnl.

In such a case, it is effective to apply pressure to atmospheric pressure by reducing the pressure in the gap between the first panel (5)' and the second panel β)' in FIG. Also, the thickness force of one or both of the transparent substrates (3) or (9) z Q, 5 w
If the pressure is less than n, the pressure reduction method described above is better than the pressurization method such as a press.Usually, the press method can be adopted as the pressure adjustment method, but if the flatness of the first panel holder' and the second panel a3)' is poor, Alternatively, if the thickness of the transparent substrate is 1M or less and the size is approximately 40° or more, it is necessary to press it with rubber or the like.

The sealing material 0z is provided around the panel with a width of 1 to 5 rIaR, but a portion is left missing in order to form a liquid crystal sealing opening]16). The sealing material 121 is adhesive lit (141
It can be provided at the same time when forming the transparent substrate (3
) or on the insulating film f121 provided as necessary. The adhesive layer (14) is used as a means for forming the sealing material (12).
1) For example, after joining the first panel (5)' and the second panel (B)', inject adhesive from the outer periphery of the panel, and then apply heat or UV rays as necessary.
The sealing material I can also be formed by solidifying by isobaric irradiation.

(Function) The remarkable difference in the function of this research from the conventional technology is that the adhesive layer +1
41. In the prior art, the spacer (11) did not have the role of bonding the first panel and the second panel (B), whereas the adhesive layer t141 of the present invention plays the role of the spacer Uυ and the first panel 8'. and the second panel (B
)′ are strongly bonded. Furthermore, since the adhesive layer d41 can be intentionally provided at any location and with any size, the display effect will not be impaired. By using a rubber-based photoresist for the adhesive layer (141).

By heating, melting, adhering, and further cyclizing, a strong adhesive layer α can be obtained. Furthermore, in conventional liquid crystal filled cells, when filling the liquid crystal (6), pressure is applied between the panel holder and the panel, and the liquid crystal is sealed with the spacer aυ in contact with the panel holder and the panel (Bl). In contrast, in the liquid crystal-filled cell according to the present invention, the panel 8'
Since the and panel (Bl') are bonded with an adhesive layer, there is no need to apply pressure when filling the liquid crystal, and workability is extremely good. In particular, the Niro liquid crystal a has extremely high viscosity at room temperature, so it is difficult to apply pressure when filling it. It is extremely advantageous when it is necessary to heat the panel holder', the panel (B)' and the ferro liquid crystal ([9], and when it is necessary to slowly cool it for the purpose of improving the orientation after placing it on the person.

In the prior art, it was difficult to maintain the electrode gap at 2 μm or less, particularly 1 μm or less, due to the machining accuracy of the spacer (1) and dirt during the spraying operation. Contact N 4 aa according to the present invention
By changing the solid ratio of the rubber resist, coating conditions, etc., the film thickness of the adhesive layer (2) can be freely changed continuously from 0.3 μm to 2 μm, and the pattern shape can be adjusted to any position. , it can be formed in any shape, and since the panel (B) is bonded with force and contact with I4α, the cell gap can be maintained, providing an extremely excellent method for manufacturing a cell for liquid crystal filling. It is something to do.

(Example) <Example 1> A transparent substrate (3) was obtained by optically polishing a 3-inch square glass substrate with a thickness of 1.6 mm to a flatness of within 2 μm. Sputtering a 40OA ITO film on the transparent substrate (3)! ! A pixel electrode (4) having a parallel line pattern with a line width of 2813 μm, a pitch of 300 μm, and a length of 60 wn was formed using a conventional photoetching method. Next, polyimide resin PIX-1400 (manufactured by Hitachi Chemical Co., Ltd.) was coated on the pixel electrode (4) with a spinner at 300 rpm for 2 minutes, and then heated at 80°C for 15 minutes.

Heated at 200° for 30 minutes and 300° for 30 minutes. Next, an alignment treatment was performed using a rubbing device to form an alignment film (5), and a first panel (5)' was manufactured. On the other hand, ITO was patterned by sputtering on the surface of an optically polished 0.5 m thick, 3 inch square glass substrate, and the line width was 280 μm in the same manner as above.
A counter electrode (8) consisting of lines with a pitch of 300 μm and a length of 6 or Im was formed, and an insulating film (131) was further provided to obtain a second panel (B).
15 viscosity 30 cp hemorrhoid fluid of OMR-83 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 300 Orpm.
Spin coating for seconds and follow the conventional photo-etching method.
A pattern with a size of 50 μm square and a pitch of 150 μm was exposed to create an adhesive layer side. At this time, the film thickness after the first event was 0.6 μm. Next, the first panel (to)' and the second panel (B)' were brought into close contact with each other, and the temperature was increased from room temperature to 180°C at a rate of 5°C/1 minute for 1 hour by applying a pressure of 1 kg/d. A cell for liquid crystal filling was produced by holding, subsequently cooling, and removing the pressure. As a result, both panels were bonded together using the adhesive layer I. At this time, the cell spacing is 0 over the entire display surface.
．． The I 2 To film pattern processing method at this time is as follows.

(1) Apply a positive photoresist on the ETO film, dry for 9°050 minutes, expose with a mask, and develop with a special developer.
After baking, it was post-baked at 130°C for 50 minutes.

(2) Next, the ITO pattern was immersed in a mixed solution of ferric chloride solution and hydrochloric acid heated to 60'C for etching.

(3) 0FPRII was removed using a special remover and washed with pure water.

In addition, before filling the liquid crystal, the liquid crystal filling cell was heated and opened under reduced pressure, and C8-1011 (C8-1011) was used as the ferro liquid crystal 19.
Chisso Corporation, #) was heated to 120°C, and the sealing port (I
Enclose the ferro liquid crystal G51 from f31.

A good liquid crystal display panel was manufactured.

<Example 2> In the same manner as in Example 1, the first panel (5) r pixel polarization (4) and alignment film (5) were formed, and JSR-CBR
- Viscosity of M2O3 (manufactured by Japan Synthetic Rubber Co., Ltd.) 25 cp
was spin-coated at 200 rpm, and the adhesive layer side was formed on the margin of the pixel electrode (4) in a pattern with a line width of 20 μm and a pitch of 600 μm according to a conventional photoetching method.

Next, a 6 inch square glass substrate with a thickness of 2.6 mlR was polished to obtain a transparent substrate (9). After forming a counter electrode (8) on the transparent substrate (9) in the same manner as in Example (1), silicon oxide was sputtered to a thickness of 5 oi to form an insulating layer.
, i was formed. Next, add ethyl cellosolve o, s to 1 g of Semicofine 5P-910 (manufactured by Toshi Co., Ltd.)
The mixture was diluted and stirred at a ratio of 1.5 g, then spin-coated at 3000 rpm for 2 minutes, and then dried at 165° C. for 3D minutes.

After that, 0FPR■ (Tokyo Ohka Kogyo Co., Ltd.!) was spin-coated on the entire surface, and a 10 μm wide pattern was exposed using a mask in close proximity to the adhesive layer (14) of the first panel, and then a non-metal special developer was applied. At the same time as 0FPRI is visualized, the Semicofine 5P-910 is etched.

Subsequently, 0FPRn was dissolved in a mixed solvent of n-butyl acetate and inopropyl alcohol at a volume ratio of 1:1. After that, the second panel a3)' was heated at 200°C for 50 minutes.
An auxiliary baser circle was formed by heating and baking at 0°C for 30 minutes. Thereafter, in the same manner as in Example 1, the first panel and the second panel were brought into close contact and heated at 150° C. for 30 minutes and then at 200° C. for 30 minutes while applying pressure to produce a liquid crystal filling cell having an auxiliary space ut+'ff. In addition.

The 1TOL pattern processing method and liquid crystal filling method at this time are also the same as in Example 1.

<Example 3> Semico Fine 5 was placed on the same transparent substrate (3) as in Example 1.
P910. A blue varnish consisting of a blue organic pigment and a dispersion aid was applied with a spinner, and after drying at 125°C for 30 minutes,
0FPRII was applied using a spinner and dried at 80° C. for 60 minutes. The above 0FPRII was exposed with a line pattern having a line width of 150 μm and a pitch of 450 μm.

The blue face was etched with an alkaline phenomenon solution, leaving an unexposed area of 150 μml. Thereafter, 0FPRII was dissolved in the same manner as in Example 2, and the temperature was raised sequentially to 2000°C for 30 minutes, 250°C for 60 minutes, and 500°C for 30 minutes to form a blue filter (jη).

Thereafter, a green filter and a red filter were sequentially formed as shown in FIG. The composition of each color varnish was as follows.

Red face, green face, blue face. Next, ITO is sputtered on the entire surface of the color filter and patterned according to the usual method while aligning with the color filter to form a pixel electrode (4) with a line width of 160 μm and a pitch of 150 μm.
And an alignment film (5) (see FIG. 2) was formed. Thereafter, the outer adhesive layer U41 was formed in the same manner as in Example 1, and a second panel C was formed.
B)' was formed, and the first panel '' and the second panel '' were joined to manufacture a liquid crystal filling cell.

Furthermore, the ITO film pattern processing method and liquid crystal filling method in this case are the same as those shown in Examples 1 and 2.

As mentioned above, about three embodiments of h'-1 are shown.Regardless of the embodiments described above, the substrate material is not limited to a glass substrate, but may also be a resin substrate or the like. Furthermore, it goes without saying that there is no question as to the structure of other layers other than the adhesive layer, the materials of each layer, the method of forming each layer, the alignment treatment method, the liquid crystal filling method, etc.

(Effects of the Invention) It has become possible to construct a liquid crystal display device using ferroelectric liquid crystal, which has been difficult in the past.

In addition, the spacer only serves as a sealant.It is now possible to use it to join panels together. Also.

This sealing method can also be easily performed without requiring much equipment.

Furthermore, it has become possible to freely and finely adjust the spacing between the spacers, and it has also become easy to freely form the shape of the spacers.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a liquid crystal filling cell according to the present invention, and FIG. 2 A, FIG. 2 B, and FIG. FIG. 7 is a panel sectional view showing a state in which the first panel (5)' and the second panel a3)' are joined. Fig. 6 is an explanatory drawing showing the arrangement of the auxiliary spacer 0', Fig. 6 is an explanatory drawing showing the first panel (5)' with a color filter, etc., and Fig. 4 is an explanatory drawing showing the arrangement of the auxiliary spacer 〇'. It is an explanatory diagram showing an example. (1)...Light source (2)...Polarizer (3)
(9)...Transparent substrate (4)...Pixel electrode or segment electrode (5) (7)...Alignment film (6)...Liquid crystal (8)...Counter electrode (or common electrode) (10)・
...Analyzer (II)...Spacer 02...
・Encapsulation material q3... Insulating film α... Adhesive layer
■'...Auxiliary spacer (1ω°°°fluoro liquid crystal 06)...Filling port (17)...Color filter

Claims (6)

[Claims] (1) Manufacture of a liquid crystal filling cell consisting of a first panel in which at least a transparent pixel electrode and an alignment film are formed on the pixel electrode on a transparent substrate, and a second panel in which at least a transparent counter electrode is formed on the transparent substrate. In the method, an adhesive layer made of photosensitive resin is formed in a substantially uniform fine shape on at least one surface of the first panel and the second panel, and the first panel and the second panel are faced to each other, 1. A method of manufacturing a cell for encapsulating a liquid crystal, characterized in that the first panel and the second panel are joined by heating under pressure. (2) The method for manufacturing a cell for encapsulating a liquid crystal according to claim 1, wherein the adhesive layer has a thickness of 2 μm or less. (3) Pressure applied from 0.5kg/cm^2 to 5kg/c
m^2 and the heating temperature is 140℃ to 160℃
Claim 1, characterized in that the first step is maintained at 180°C to 250°C.
2. Method for manufacturing a cell for encapsulating a liquid crystal as described in Section 1. (4) The method for manufacturing a liquid crystal filling cell according to claim 1, characterized in that a rigid auxiliary spacer having the same thickness as the adhesive layer is formed near the adhesive layer. (5) The method for manufacturing a cell for encapsulating a liquid crystal according to claim 1, wherein the photosensitive resin is a rubber-based photoresist. (6) The method for manufacturing a liquid crystal filling cell according to claim 1, wherein a pixel electrode or a counter electrode is formed on the transparent substrate of the first panel or the second panel via a color filter.