Substrate, display device and substrate preparation method

Abstract

The invention discloses a COA (color filter on array) substrate which comprises a TFT (thin film transistor), a color layer and a pixel electrode. A via penetrating through the color layer is arranged above a drain of the TFT, a conductive packing layer is arranged in the via, and the pixel electrode is connected with the drain of the TFT through the conductive packing layer. By the aid of the conductive packing layer formed in the via of the COA substrate, the problem of line breakage of the conductive layer caused by excessive depth of the via or unsmooth inner surface of the via is effectively solved, and yield is increased. The invention further provides a display device and a COA substrate preparation method.

Description

technical field [0001] The invention relates to the technical field of liquid crystal display, in particular to a substrate, a display device and a preparation method of the substrate. Background technique [0002] COA (Color Filter on Array) technology is a technology that prepares color layers on array substrates. The basic structure of COA substrates is as follows: figure 1 As shown, a thin film transistor TFT, a color layer 4 and a pixel electrode 5 are sequentially formed on a base substrate 1. There is a protective layer 3 between the drain 2 and the color layer 4 of the TFT, and a penetrating color layer 4 is arranged above the drain 2. The via hole is connected between the pixel electrode 5 and the drain electrode 2 . Because there is no alignment problem between the color filter substrate and the array substrate in the display panel of the COA structure, it can reduce the difficulty of the box alignment process in the display panel manufacturing process and avoid t...

AI Technical Summary

Problems solved by technology

[0003] When the implementation of COA technology adopts the fabrication sequence of sequentially forming the drain electrode 2-protective layer 3-color layer 4-pixel electrode 5 on the substrate 1, it is necessary to form a pass through the color layer 4 and the protective layer 5 above the drain electrode 2. hole, such as figure 1 The structure shown in the middle dotted line; the specific formation method is as follows figure 2 Shown: as figure 2 As shown in a to c in the middle, firstly, the first opening A is left when preparing the colored layer 4, and the protective layer 3 exposed at the position of the first opening A is dry-etched using the colored layer 4 as a mask to form a via hole, This kind of production can reduce a patterning process (generally including glue coating-exposure-development-etching-stripping and other processes); however, the protective layer 3 will produce over-etching in the dry etching process, that is, the protective layer 3 is in the color layer 4. After the part of the exposed part of the lower edge of the first opening A is etched, a part will be etched laterally, so that the edge size of the second opening B formed by the protective layer 3 is larger than that of the lower edge of the first opening A of the color layer 4. size, such as figure 2 As shown in middle d, therefore the surface of the entire via hole formed is uneven, which will lead to poor disconnection when forming the pixel electrode 5, such as figure 2 as shown in e

At the same time, since the via hole runs through the color layer 4 and the protective layer 3 (the sum of the thicknesses of the color layer 4 and the protective layer 3 is about a few microns), the depth of the via hole is relatively deep, and it is easy to cause disconnection when forming the pixel electrode 5 bad

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