JPH02223923A - Display panel - Google Patents

Abstract

PURPOSE:To obtain the constitution of a picture element adapted to a large area display by using a consecutive pattern such as a line or a curve. CONSTITUTION:A thin film semiconductor layer 2 which is the active layer of a TFT element combined with a part of a wiring 5 on a signal side is formed on a glass substrate and it is formed in an island shape by performing etching after applying resist. Then, a gate insulating film is formed all over the surface of a substrate. Furthermore, after forming a thin film for wiring on a scanning side, etching work is performed in line shape and doping is performed by ion implantation, etc., so as to form a source, gate and drain electrode and make the resistance of the wiring 1 on the scanning side lower. Furthermore, the insulating film is formed for passivation if necessary and a contact part 4 in a line shape is formed by etching, etc., and the wiring 5 on the signal side and a display electrode 3 are formed by using a transparent electrode. The consecutive pattern in the line shape is used much in order to easily form the resist when the pattern is formed in a printing method and the constitution of the picture element appropriate for the printing method is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a flat display using liquid crystal, etc., and particularly to the structure of a large active matrix type liquid crystal display using switching elements such as thin film L-transistors. The present invention relates to a structure suitable for increasing the area or increasing the definition.

[Conventional technology]

Switch elements such as thin film transistors and diode elements are formed on a transparent substrate such as glass and laminated with a substance having electro-optic properties such as liquid crystal. The so-called active matrix display is a method suitable for high definition and large area, such as IEE and Floseeding 5.
9 (1971) p. 1566 (Proeeedin
gs of IEEE, 59.

In recent years, thin film transistors using amorphous silicon (a-S
i T F T ; amorphous 5ili
con Th1n Fi]mTransistor) and a transistor using polycrystalline silicon (p-S
i T F T ; 2o1yerystalline
Active research and development is being conducted using Si TFTs. This method has diagonal dimensions ranging from about 1 inch to 10 to 1 inch.
Various sizes have been developed, from small to large, up to about 4 inches, and displays with even larger specifications are about to be developed. However, this manufacturing process involves photo-etching, and the biggest challenge is manufacturing fine patterns with high precision.

[Problem to be solved by the invention]

In such a conventional photoetching process, the minimum processing line width is determined by taking into account the accuracy of the photomask, the accuracy of the mask aligner, the accuracy of the pattern due to light interference or diffraction, or the expansion and contraction of the substrate, and the pattern is formed accordingly. It uses the process of creating. However, as the substrate size increases, the required specifications for these precisions become stricter, and it becomes necessary to design the pattern with a margin. However, the conventional photoetching process has limitations in productivity and cost, and new methods of forming resist patterns using printing methods are being tried.

The pattern forming method using the printing method is less accurate than the photoetching method for small areas, but it has the advantage of higher throughput as the area becomes larger, and is an effective method when relatively high processing precision is not required for large areas. be. However, in order to increase the aperture ratio of the pixel portion (the ratio of the effective display electrode to the area of the pixel), which has a large effect on the display characteristics of the display, it is desirable to reduce the minimum processed line width. When considering the direction of processing, it is necessary to significantly change the concept of the design method using the conventional photoetching method.

An object of the present invention is to provide a pixel structure suitable for printing methods.

[Means to solve the problem]

The above object is achieved by using a structure in the printing method that greatly reduces processing precision in the structure of the original and in the step of transferring resist from the original onto the processed substrate.

[Effect]

In printing methods, it is difficult to form dot-like patterns or minute island-like patterns, and continuous patterns such as straight lines and curves are easier to process. By using this continuous pattern, a pixel configuration suitable for increasing the area can be obtained.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure shows the configuration of one pixel.

A TFT element is placed at the intersection of the signal side wiring (drain pass line) 5 and the scanning side wiring (gate pass line) 1.

It consists of a pixel electrode 3 made of a transparent electrode material connected to the source electrode of the TFT element. As for this formation method, first, a thin film semiconductor layer 2 serving as the active layer of the TFT element and part of the signal side wiring is formed on a glass substrate, and a resist is applied and then etched to form an island shape. Next, a gate insulating film is formed over the entire surface of the substrate. Furthermore, after forming a thin film for scanning side wiring, it is etched into a linear shape as shown in Figure 1, and doped by ion implantation etc. to form a source.

At the same time as forming the gate and drain electrodes, the resistance of the scanning side wiring is reduced. Further, if necessary, an insulating film is formed for passivation, linear contact portions 4 are formed by etching, etc., and signal side wiring 59 and display electrode 3 are formed using transparent electrodes.

At this time, the signal side wiring 5 and the display electrode 3 may be formed separately using different materials.

The above configuration is characterized in that when forming a pattern by a printing method, linear continuous patterns are frequently used so that resist formation is easy.

Figures 2(a) to 2(d) show patterns suitable for the printing method. Figure 2(a) is a pattern formed linearly in the printing direction, and has a particular tolerance for misalignment in the printing direction. You can make it bigger. In FIGS. 2(b) to 2(d), the pattern is always present on the substrate at any position in the direction perpendicular to the printing direction. By doing so, the spacing between the original plate and the substrate is kept constant during pattern printing due to the unevenness caused by the presence of the pattern on the original plate, making it possible to form a pattern with high precision.

FIG. 3 shows the concept of a printing method using an embodiment of the present invention.
In this method, a resist 8 is formed on a roll-shaped original 7 on a glass substrate 6, and a pattern is formed while making one rotation.

In order to form the pattern shown in FIG. 1 using this method, it is sufficient to rotate the insertion direction of the substrate by 90 degrees to match the direction of the pattern.

In Fig. 3, the original is in the form of a roller, but even if the original is flat, the present invention can be achieved by determining the printing direction by considering the direction with good accuracy when placing the original on the substrate. It goes without saying that the embodiments can be applied.

〔Effect of the invention〕

According to the present invention, since a resist pattern can be formed with high precision by a printing method, it is possible to easily process a display or the like using a large-area substrate.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a pixel portion according to an embodiment of the present invention, and FIG.
The figure is a pattern diagram of a resistor 1 suitable for the present invention, and FIG. 3 is a conceptual diagram of a printing method. 1...Scanning side wiring, 3...Display electrode, 5...Signal side wiring. S--One signal, one rule, countermeasure

Claims (1)

[Claims] 1. A display panel in which wiring, contact holes, and electrodes are formed as a continuous pattern spanning at least two or more pixels in an active matrix liquid crystal display formed by laminating TFTs and liquid crystals on a glass substrate.