JPH03163418A - liquid crystal element - Google Patents

Abstract

PURPOSE:To obtain the liquid crystal element having good display quality by simultaneously forming spacers of the same thickness as thickness of electrodes on at least one glass substrate in the regions, exclusive of a display region, within a cell by using the same material. CONSTITUTION:The transparent electrodes, 2, 2 having 3,000Angstrom film thickness are formed in a stripe shape on the upper and lower glass substrates 1, 1' so as to face each other like an orthogonal matrix to form the display region (a). The lead electrodes 3, 3' of the same material and thickness as the material and thickness of the electrodes 2, 2' are simultaneously formed and the spacers 4, 4' for maintaining a prescribed cell gap uniformly at 1.5+ or -0.1mum over the entire surface by again using the same material to the same thickness. The spacers 4, 4' are formed to the shape extending the striped electrodes 2 up to the parts interposed with a sealing material 6 on the upper substrate 1 side and are provided on the outer side of the electrodes 2' in parallel therewith on the lower substrate 1' side. After the respective substrate surfaces formed with the patterns are subjected to an orientation treatment, glass beads 7 of 1.5mumphi mixed in the sealing material 6 by 1% are transferred by flexographic printing to 1mm width and 3mum thickness only on the substrate on one side. The substrates 1, 1' are stuck to each other and a buffer material is inserted between the substrates 1 and 1'. The element is then heated to cure the sealing material 6.

Description

[Detailed description of the invention]

[Field of Industrial Application] The present invention relates to a structure of a liquid crystal display element in which a uniform cell gap is obtained by forming a spacer having the same thickness as an electrode in a region other than a display region within a cell.

[Prior art]

The structure of a conventional liquid crystal display element is shown in Figures 5 and 6. Conventionally, the manufacturing method of liquid crystal elements consists of two glass substrates 1.1
For each of ', electrodes 2.2
After forming a pattern of ′ and at the same time forming a pattern of lead electrodes connected to each electrode, the surface is subjected to orientation treatment. Next, the electrode surfaces of the two glass substrates 1 and 1' are made to face each other, the periphery is sealed with a sealing material 6, and the inside of the cell surrounded by the sealing material 6 is bonded together via the gap material 5. At this time, pressure was applied using a press or the like to form a predetermined cell gap. [Problem to be Solved by the Invention] However, in the above conventional example, as shown in FIGS. 5 and 6, the display area a where the electrodes 2 and 2' face each other in a bonded state and the other area In b, when the upper and lower glass substrates 1.1' are made completely parallel (when viewed from the side), the gap is different by the thickness of the formed electrode 2.2', so the pressure cannot be applied uniformly over the entire surface. When this happens, the gap in each region is maintained by the filler and gap material 7 in the cell gap material 5 and sealing material 6, so that the electrode 2.
Stress is concentrated at the outer periphery of display area a where 2′ are opposed to each other. As a result, the gap material 5 may be deformed or destroyed in that area, or the gap material 5 may become embedded in the electrode 2.2', resulting in a disadvantage that the thickness of the gap becomes thinner than in other display areas. In particular, for simple matrix display elements such as ferroelectric liquid crystal display elements, which have a very thin gap thickness of 1 to 2 μm, and in which the electrodes of each substrate are arranged in stripes and are orthogonal to each other,
When the display area is increased and the number of lines is increased, and the electrodes must be made thicker to prevent a decrease in wiring resistance, the above-mentioned gap non-uniformity poses a major problem. The present invention was made in view of the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a liquid crystal display element that can reduce stress concentration due to gap differences and form a uniform cell gap in the process of bonding glass substrates. [Means and effects for solving the problem] According to the present invention, a spacer having the same thickness as the electrode is formed on at least one glass substrate in an area other than the display area in the cell, and is made of the same material and simultaneously formed. By forming it in the process, in the process of bonding two glass substrates together and further applying pressure,
Stress concentration due to the gap difference between the display area where the electrodes face each other and other areas when the upper and lower glass substrates are made completely parallel can be avoided, and the gap can be thinned due to breakage or deformation of the gap material. [Example] Figures 1 and 2 show a first embodiment of the present invention (a liquid crystal display element using a ferroelectric liquid crystal according to the present invention). An example is shown below. In the same figure, 1.1
' is the upper and lower glass substrates with a thickness of 1.1 mm, 2.2' is a transparent electrode (I To) with a film thickness of 3000 mm formed in a stripe shape on each glass substrate,
In the bonded state, they face each other in an orthogonal matrix, and this area becomes the display area a. 3.3' is a lead electrode formed at the same time with the same material and film thickness as the transparent electrode 2.2'. 4 and 4' in region b have a predetermined cell gap of 1.5
This is a spacer formed to maintain uniformity of ±0.1 μm over the entire surface. These substrates 4, 4' are also transparent electrodes 2.
2' and lead electrode 3.3' are formed at the same time using the same material and thickness, and the formation method is the same as that of glass substrate 1.1.
ITO was formed into a film by sputtering on each substrate before bonding the spacers 4 and 4', and then photolithography etched (to form a pattern). On the substrate 1 side, a striped electrode 2 is provided extending to the part through the sealing material 6, and on the lower glass 1' side, a seal is provided outside and parallel to the outermost striped electrode 2'. Next, after applying an orientation treatment to the surface of each patterned substrate, one side of the substrate (only for flexographic printing) was placed in a stripe pattern at a position overlapping with the material. A mixture of 1% (wet) silica microbeads manufactured by Mitsui Toatsu Co., Ltd. in a sealing material 6 (for example, Structobond Gap material 5 made of glass beads with a diameter of 1.5 μm to maintain the gap (for example, products, catalytic
250-35 silica microbeads) evenly distributed over the entire surface.
Sprayed at a density of 0/mm'. After that, the upper and lower glass substrates 1.1' are covered with striped transparent electrodes 2.2'.
They were laminated together facing each other perpendicularly, and then pressurized for 2 minutes at 70°C and 2.5κg/co" using a heating press. However, in order to make the pressure distribution uniform over the entire surface, A U-shield material made of maltbrene of *1. Since the spacers 4 and 4' described above are formed in the area b, the glass substrate 1.1' is kept parallel by the gap material 5 with a diameter of 1.5 μm and the glass beads 7 in the sealing material 6. Therefore, the gap material 5 is not crushed due to stress and concentration, and the predetermined cell gap is 1.5±.
A uniform thickness of 0.1 μm could be formed over the entire surface. After that, the sealing material 6 was cured by heating at 170°C for 4 hours, and a ferroelectric liquid crystal material was further sealed in the cell, and when it was connected to an electric driver and driven, it was found that there were switching defects and visual defects due to differences in threshold characteristics. We were able to obtain a ferroelectric liquid crystal display element with very good display quality and no color unevenness. FIGS. 3 and 4 are diagrams showing another embodiment of the present invention. Here, the substrate 4 is made of ITO as in the above embodiment.
They were formed at the same time using the same material and thickness as electrode 2 and lead electrode 3, which were made by 1,500 people. However, that area is electrode 2.2
' display area a and lead electrode 3.3 formed by facing each other.
Striped electrodes 2 and 2' were simply formed on each of the glass substrates in region b, excluding region C where electrodes 2 and 2' faced each other, extending to the part through the sealing material. Next, after performing orientation treatment on the surface of each patterned substrate, glass beads 7 with a diameter of 1.65 μm are applied to one side of the substrate by flexographic printing with a sealing material 6 (for example, Structbond XN-21F manufactured by Mitsui Toatsu ■). A mixture of 1% (wet) and 1% (wet) is transferred to a width of 1 am and a thickness of 3 μm. Furthermore φ1.5μ
Gap material 5 (for example, a product,
Silica microbeads (manufactured by Catalyst Kasei) were uniformly coated with -250
Sprayed at a density of ~350 seeds/■2. Thereafter, as in the previous embodiment, the upper and lower glass substrates 1.1' are connected to transparent electrodes 2.
．． 2' were pasted together facing each other, and the entire surface was heated uniformly at 70°C with a 1.0 mm moltprene buffer sandwiched between the press plate surface and the glass surface using a heated press plate.
Pressure was applied at 2.5 kg/cm' for 2 minutes. At this time, the area b where the spacer 4 is formed other than the display area a where the electrode 2.2' faces and the lead electrode 3.3
In the area C where the electrodes 1.1' and 1.1' face each other, there is a difference in the total thickness of the electrode 2.2' formed on the upper and lower glass substrates 1.1', the lead electrode 3.3', and the spacer 4, that is, the difference in the total thickness of the upper and lower glass substrates 1.1'. 1. Since the gap thickness is different when 1' are viewed completely parallel, the gap in each area when pressurized is maintained by the gap material 5 and the glass beads 7 in the sealing material, so the difference between area b and area The display area near C is subject to some stress concentration. However, the destruction of the gap material 5 occurring in that part or the transparent electrode 2.2 of the gap material 5
The problem that the gap thickness becomes thinner than the other display area part a due to the cutting into ' is not a practical problem. That is, area b
There is a spacer 4 or lead electrode 3.3' with a thickness of 1500 in area C, and the difference in thickness from display area a is 15.
Since there were only 0.00 people (0.15 μm), we were able to keep the cell gap within the specified cell gap of 1.5 ± 0.1 μm. [Effects of the Invention] As explained above, a spacer having the same thickness as the electrode is formed on at least one glass substrate in an area other than the display area in the cell, and moreover, it is formed using the same material and in the same process. This makes it possible to provide a liquid crystal display element with good display quality without increasing manufacturing costs at all.

[Brief explanation of the drawing]

Figure 's1 is a plan view of a liquid crystal display element according to the first embodiment of the present invention, Figure 2 is a sectional view taken along line AA' in Figure 1, and Figure 3 is a second embodiment of the present invention. 4 is a sectional view taken along line AA' in FIG. 3, FIG. 5 is a plan view showing a conventional liquid crystal display element, and FIG. 6 is a sectional view taken along line A-A in FIG. -A' is a cross-sectional view. 1.1': glass substrate, 2.2': electrode, 3.3': lead electrode, 4.4' varnish baser 5 = gap material, 6: sealing material, 7: glass beads. patent

Claims (5)

[Claims] (1) Two substrates on which electrodes are formed are placed facing each other with the electrode surfaces facing each other with a predetermined gap between them, a gap material is interposed in the electrode facing area between both substrates, and the area around the electrode facing area is sealed. 1. A liquid crystal element, characterized in that a spacer having the same thickness as the electrode is provided on at least one substrate of the sealing material-sealed portion. (2) The liquid crystal element according to claim 1, wherein the spacer is made of the same material and formed in the same process as the electrode. (3) The electrodes are composed of a plurality of striped electrodes arranged in parallel, each electrode of two substrates is arranged orthogonally to form a matrix, and each striped electrode is continuously connected to a lead electrode of the same thickness and the same material. 3. The liquid crystal element according to claim 2, wherein: are formed in parallel on one side edge of each substrate. (4) The spacer is formed continuously with each stripe-shaped electrode so as to extend to a sealing material disposed portion on the side opposite to the lead electrode of each stripe-shaped electrode. The liquid crystal element described in . (5) The liquid crystal element according to claim 3, wherein the spacer is formed on the outside of the outermost striped electrode and parallel to the outermost striped electrode until it overlaps with the sealing material.