JPS5971081A - Liquid crystal display and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] The present invention relates to a reflective liquid crystal display device and a method for manufacturing the same, and more particularly to a liquid crystal display device with a reflective portion improved to have a white surface and a method for manufacturing the same. Regarding.

[Technical background of the invention and its problems] The contrast of a liquid crystal display device, for example, a reflective display device using a guest-host type, largely depends on the reflective surface, which is a white surface. A white surface is desirable. As a method for realizing this surface, there is a method using a mask for forming a white surface disclosed in Japanese Patent Application Laid-Open No. 57-66473 (2). There was a drawback that absorption of light occurred due to reflection.As a means to improve this drawback, the applicant has already filed Japanese Patent Application No. 7923/1983. After patterning with photoresist, wet etching is performed to form an uneven shape on the organic insulating layer, and after the uneven surface is smoothed by heat treatment, a highly reflective metal layer is deposited on top of it to form a reflective surface. According to this method, the uneven surface of the metal layer can be formed smoothly, resulting in fewer multiple reflections and a bright, high-contrast reflective surface, but when wet etching is used in the mass production process. When etching is carried out over a wide area, there is a difference in the depth of etching between the periphery and the center, which may result in an uneven pattern shape.Furthermore, the taper angle of the unevenness changes due to subtle differences in the adhesion of the photoresist. That is, in the formation of a white surface of the reflective part, further improvements in uniformity and reproducibility have been desired.

[Purpose of the invention]

The present invention improves on the above points, and aims to provide a liquid crystal display device that has a white reflective area with extremely high uniformity and reproducibility, and a method for manufacturing the same.

[Summary of the invention]

The present invention provides a liquid crystal display device having a reflective portion in which a metal layer having a high reflectance is formed on the organic insulating layer, and a method for manufacturing the same.

゛[Embodiments of the invention] The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of a liquid crystal display device according to the present invention.

On the substrate (lυ, a convex portion having a taper of 5 degrees to 80 degrees with respect to the substrate plane to create unevenness, for example, the center ua2
1 is formed, and this core material a'! An organic insulating layer Ql of polyimide resin is formed to cover J, and a highly reflective metal layer (141) is further formed on the organic insulating layer to form a uniform white surface over a wide range.

Next, FIG. 2 shows an embodiment of the manufacturing method of the present invention.

This will be explained with reference to FIG. Figure 2 (a) (b) (
C) (d) is a sectional view of the device shown in the order of steps. First, a large number of core materials (121) are formed on the substrate αD using any of the etching method, plating method, lift-off method, etc. If the method for forming the core material 03 is, for example, the etching method, then the lamination method, such as CVD, sputtering, etc. , evaporation, spinner coating, etc.) As shown in FIG. 20
form. This layer Q1) is masked c! Selective etching is performed using 4. Here, the etching pattern is preferably arranged in a high density as shown in Figure 3, for example, the pitch is l.
It is preferably circular with a diameter of ~50μ and a thickness of o, t-toμ.

The part to be etched is circle 01) or the part other than the circle 32
Either of these is fine. In this case, anisotropic etching, for example dry etching RIE (eacLive Io
n Etching) for one month, it is possible to form a highly accurate pattern. Also suitable gas,
By appropriately selecting conditions such as gas pressure, core material a3
A moderate taper can be formed. like this(
After forming the core material a as shown in FIG. 2(b), the mask CJ3 is removed and an organic insulating material having a predetermined concentration and viscosity, such as a polyimide resin layer a3, is formed as shown in FIG. 2(C).
Form as shown.

For this forming method, it is preferable to use means such as rotation or vibration.
Spinner coating is performed at 000 rpm to 500 rpm to form α wrinkles on the organic insulating layer. In this case, by changing the rotation speed and the viscosity of the organic insulator, the organic insulator layer a
3. The shape of the unevenness can be changed. Next, as shown in FIG. 2(d), a single layer of a metal with high reflectance, such as Ae, Ag, or an alloy containing these, is placed directly on the organic insulating layer, or a metal with high reflectance is placed on the surface. is deposited in multiple layers to form a metal layer αa. That is, according to the structure and manufacturing method as described above, a polyimide resin layer having smooth unevenness is obtained.
3 can be uniformly formed over a wide range.

Therefore, by depositing the metal layer Oa on the polyimide resin layer a3, which is an organic insulator, we can eliminate multiple reflections due to the occurrence of hiccups and improve the uniformity of the reflective part, which has a smooth and extremely bright white surface. <I can do it.

Next, an example of a liquid crystal display device using the reflective section of the above embodiment will be explained with reference to FIG. First, the reflection part is used only as a reflection plate, and a liquid crystal (41) is sandwiched between two glass substrates (44) on which a plurality of band-shaped transparent electrodes (42) and a counter electrode (43) are formed. A reflective plate (45) is disposed at a predetermined portion of the optical path passing through the liquid crystal layer (41) to constitute a reflective liquid crystal display device. Reflector plate in this case (45
) has the structure shown in FIG. 1, and the reflecting portion αa is formed on the entire surface of one side of the reflecting plate.

Furthermore, FIG.
? This is an embodiment in which the four poles (51) are constructed from the reflectors shown in FIG. 2.

That is, a matrix is formed by a transparent electrode (43) formed on a glass substrate (44) sandwiching a liquid crystal layer (41) and an electrode (51) which also serves as a reflective surface formed on a substrate (45). There is.

The reflecting portion of the above embodiment is formed on the substrate (45), and Iz
However, when the reflective metal layer also serves as a display electrode as in this case, the metal layer is separated into stripes or islands.

Next, FIG. 6 shows a case in which a C semiconductor substrate is used as the substrate 0υ in FIG.
This is an example applied to the IJ system, in which a switch/capacitor array consisting of an S capacitor (63) is integrated, and a cross-sectional view of one pixel is shown.

On the substrate (61) (1), the reflective part shown in Fig. 2 is formed, and on the organic insulating layer (64), the reflective part metal layer (65)
In this case as well, the reflective metal layer (65) also serves as the display electrode (65), and is interconnected to the capacitor through the through hole (69) and separated into islands. Display electrodes formed in this way (
65) and a glass substrate (67) on which transparent electrodes (66) are formed, a liquid crystal layer (41) is sandwiched between the glass substrate (67) and a matrix type liquid crystal display device. In this case, the substrate may be an SOS substrate, a substrate on which TPT is formed on glass, etc. in addition to the above. In order to eliminate unevenness on the board, Figure 7 (
A smoothing layer (71) is provided as shown in a), and a two-core material α2 is formed on the smoothing layer (71), or unevenness is created by using the smoothing layer as a core material as shown in FIG. 7(b). The present invention can also be applied to a substrate having. Furthermore, although an example has been described in which an island-shaped core material is formed on the substrate, a structure in which the substrate surface has a large number of island-shaped convex portions may also be used. Furthermore, in the above embodiments, a large number of convex portions are described as being arranged in a regular manner; however, a brighter white reflective surface can be obtained if the convex portions are irregularly arranged and irregular in size.

〔Effect of the invention〕

As explained above, 12 According to this invention, a wide space between substrates,
There will be a slight decrease in the number of lots between lots.
It is possible to obtain a liquid crystal display device having a bright white surface with smooth irregularities and excellent uniformity and reproducibility, and a method for manufacturing the same.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a diagram for explaining an embodiment of the apparatus of the present invention, and FIGS. A sectional view of FIG.
1 to 6 show the reflection plate according to the present invention in a liquid crystal display device;
A cross-sectional view of the tank to explain an example of its application, Fig. 7(a) (
b) is a cross-sectional view σ] for explaining another embodiment of the device of the present invention. 11.61.72... Substrate 13.64... Organic insulating layer 22...
...... Etching mask 14.51.65... Reflective metal layer 12...
・・・・・・・・・・・・ 6-phase to create unevenness 44.67 ・・・・・・・・・ Glass substrate 42.43
．． 66...Transparent conductive film 41...
・・・・・・Liquid crystal layer 45・・・・・・・・・・・・Substrate 61 with white surface formed・・・・・・・・・・・・・・・・・・
Semiconductor substrate 62・・・・・・・・・・・・MO8I
”ET63・・・・・・・・・・・・MOS capacitor (7317) Agent Patent attorney Ken Chika
Yu (1 other person) Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (7)

[Claims] (1) In a reflective liquid crystal display device, a substrate provided with a large number of concave or convex portions, and a substrate provided on this substrate,
an organic insulating layer whose surface has a smooth uneven shape corresponding to the shape of the concave or convex portion; and a metal layer provided on the organic insulating layer and having a smooth uneven shape. A liquid crystal display device characterized by: (2) The liquid crystal display device according to claim 1, wherein the organic insulating layer is made of polyimide resin. (3) The liquid crystal display device according to claim 1, wherein the convex portion is formed irregularly and has a taper of 5 degrees to 80 degrees with respect to the plane of the substrate. (4) The liquid crystal display device according to claim 1, wherein the substrate is composed of a substrate having unevenness and a smoothing layer formed on the substrate-F having unevenness. (5) The liquid crystal display device according to claim 1, wherein the metal layer also serves as a display electrode. (6) When manufacturing the reflective surface of a liquid crystal display device, there is a step of forming a substrate having a large number of concave or convex portions, and a step on which the surface of the substrate has smooth concavities and convexities corresponding to the shape of the concave or convex portions. 1. A method for manufacturing a liquid crystal display device, comprising: forming an organic insulating layer having a shape; and forming a metal layer on the organic insulating layer. (7) The method for manufacturing a liquid crystal display device according to claim 6, wherein the organic insulating layer is formed by spinner coating.