JPS62247330A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To lessen a difference of retardation between a non-electrode part and an electrode part, and to obtain the good appearance by making the surface of the electrode part which drives the liquid crystal layer and the surface of the non-electrode part to a same level on the surface of the liquid crystal layer side of a pair of the substrates inserted the liquid crystal layer there-between. CONSTITUTION:The ITO film having 1,500Angstrom thickness is formed on the glass substrate 1. At the time of working ITO to the electrode 2 having the prescribed pattern by means of a lithography, the electrode and the non-electrode are made to the same level by washing the substrate remaining a pattern of the photoresist as it is, and then by forming the SiO2 film 6 having 1,500Angstrom thickness on the substrate by means of the sputtering method, followed by removing the photoresist. In the liquid crystal display element used the obtd. substrate, the electrode 2, SiO2 6 and the orientation film 3 are formed on the inner surface of the liquid crystal side of the substrate 1, and the electrode 2 and the SiO2 6 mounted on the non-electrode part are made to the same level. The liquid crystal 4 is enclosed with the seal 5 and the two sheets of the substrates 1. Thus, the difference of the retardation of between the electrode part and the non-electrode part is lessened at all, thereby obtaining the good appearance.

Description

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

[Conventional technology]

As shown in FIG. 4, the conventional liquid crystal display element includes a substrate 1 on which electrodes 2 and an alignment film 5 are formed, and a liquid crystal layer 4 enclosed by a seal 5 that adheres the two substrates 1. The electrode 2 had a thickness of about several hundred to several thousand λ, and the alignment film 3 had a thickness of about several tens to several hundred λ. The distance between the two substrates (so-called cell gap) is approximately 5 to 10 μm.The difference between distance a and distance (a-b) shown in Figure 4 is α1 to Q.
, which is about 3 μm, which is about 5% of the cell gap.

[Problem that the invention seeks to solve]

In the conventional liquid crystal display element, as mentioned above, in FIG.
The difference between the gap a in the part without the electrode 2 and the gap b in the part with the electrode 2 was twice the thickness of the electrode 2.

The difference in cell gap (a-b) of such a liquid crystal display element is
In particular, in liquid crystal display devices that utilize birefringence mode, this appears as a difference in beam turbulence, which significantly deteriorates display quality.The inventors have conducted experiments and found that in order to satisfy the non-lighting appearance, the above-mentioned The cell gap difference (a-
b) is preferably 2000λ or less, and the smaller the difference (a-b), the better the quality of the screen was obtained. Therefore, it has been found that the thinner the electrode 2 is, 1000λ or less, the better in order to obtain a good appearance. However, as is well known, recently, liquid crystal display elements are required to have large capacity and high resolution, and as they become larger, the wiring resistance must be lowered. It became necessary to wire the . When making electrode 2 thicker, in order to obtain good wiring resistance, the lowest resistance transparent electrode I
Even TO requires a thickness of about 1000 to 1500λ, and when wiring a good metal conductor, the appearance is poor because it is itself opaque.

As described above, as long as the conventional structure of the liquid crystal display element shown in FIG. 4 is used, deterioration in appearance due to retardation cannot be avoided.

[Means for solving problems]

In order to solve the above conventional problems, the inventors invented a liquid crystal display device using a liquid crystal display element characterized in that the electrode surface and non-electrode surface of the substrate used in the liquid crystal display element are flat. did.

[Effect]

The present invention will be described in detail below using Examples.

〔Example〕

<Example 1> A 1sooX ITO film was formed on a glass substrate 1, and J) ITO was processed into an electrode 2 in a predetermined pattern by photolithography. At that time, the photoresist pattern was left as it was, and after cleaning the substrate, a 1500λ S to z film 6 was formed by sputtering, and then the photoresist 7 described above was removed. It became flat.

A liquid crystal display element was created using such a base material.

A cross-sectional view of the liquid crystal display element of this example is shown in FIG.

In FIG. 1, an electrode 2.5 loz6 and an alignment film 3 are formed on the inner surface of the substrate 1 on the liquid crystal side.
iOz6 is flat. The liquid crystal 4 is enclosed by a seal 5 and two substrates 1.

In the liquid crystal display element prepared in this manner, there was no difference in adhesive tarp between the electrode portion and the non-electrode portion, and a very good appearance was obtained.

<Example 2> A negative pattern of an electrode pattern is formed on a glass substrate 7 by photolithography, and the substrate 7 is coated with hydrofluoric acid.
500λ etched. After the photoresist was removed and ITO III was formed, an electrode pattern was formed by photolithography and electrode 2 was processed, and the electrode portion and non-electrode portion were flat.

A liquid crystal display element was created using such a base material.

FIG. 2 shows a cross-sectional view of the liquid crystal display element of this example.

In FIG. 2, an ITO electrode 2 is formed in a groove of a substrate 7, and an alignment film 5 is placed thereon.

The liquid crystal 4 is enclosed by a seal 5 and a substrate 7.

In the liquid crystal display element prepared in this manner, there was no difference in adhesive tarp between the electrode portion and the non-electrode portion, and a very good appearance was obtained.

<Example 3> A 1500 mm thick ITO film was formed on a glass substrate 1, and the ITO was processed into a predetermined pattern of electrodes 2 by photolithography. Thereafter, a polyimide film 8 was applied to a thickness of 1.5 μm, and the surface of the polyimide film 80 was found to be flat.

A liquid crystal display element was created using such a base material.

A cross-sectional view of the liquid crystal display element of this example is shown in FIG.

In FIG. 3, an ITO electrode 2 is formed on a substrate 1, and a polyimide film 8 is further formed. LCD 4 has stickers 5 and 2
It is enclosed in a single substrate 1.

In the liquid crystal display element prepared in this manner, there was no difference in adhesive tarp between the electrode portion and the non-electrode portion, and a very good appearance was obtained.

〔Effect of the invention〕

As described above, the liquid crystal display element according to the present invention has an excellent appearance, and the liquid crystal display device incorporating the liquid crystal display element according to the present invention provides very good display quality.

Furthermore, as shown in Example 1, the resist used for patterning the ITO electrode can be used to form a film by the lift-off method, making it possible to obtain a high-quality liquid crystal display element with almost no increase in process load. Furthermore, as shown in Example 3, a high-quality liquid crystal display element can be obtained without increasing the number of steps.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an embodiment of the present invention. FIG. 2 is a cross-sectional view of Embodiment 2 of the present invention. FIG. 3 is a cross-sectional view of Embodiment 5 of the present invention. FIG. 4 is a diagram showing a cross section of a conventional liquid crystal display element. 1... Substrate 2... Electrode 3... Alignment film 4...
・Liquid crystal layer 5...Seal 6...5iOz7...Substrate 8...Polyimide films a and b indicate the distances in FIG. 4. Applicant: Seiko Epson Corporation Figure 2

Claims (2)

[Claims] (1) A liquid crystal display device characterized in that, on the liquid crystal layer-side surfaces of two substrates that sandwich the liquid crystal layer, the surface of an electrode portion that drives the liquid crystal layer and the surface of a non-electrode portion are flat. . (2) An insulating material is formed on the surfaces of the two substrates sandwiching the liquid crystal layer on the liquid crystal layer side, at least in a portion other than the electrode portions that drive the liquid crystal layer. The liquid crystal display device according to item 1.