THIN FILM TRANSISTOR SUBSTRATE OF LIQUID CRYSTAL DISPLAY PANEL
A thin film transistor substrate of a liquid crystal display panel and manufacturing method thereof are disclosed. The thin film transistor substrate of the liquid crystal display panel includes a substrate, a storage capacitor electrode, a first insulated layer, a gate electrode, a gate insulated layer, a patterned semiconductor layer, a source electrode, a drain electrode, a second insulated layer, and at least one pixel electrode. A part of the storage capacitor electrode overlaps a part of the pixel electrode to form a storage capacitor and the storage capacitor electrode includes a patterned transparent conducting layer and a patterned opaque conducting layer. Moreover, the patterned transparent conducting layer and the patterned opaque conducting layer are defined by a gray-tone mask, and an area of the patterned transparent conducting layer is larger than an area of the patterned opaque conducting layer to improve the aperture ratio.
1. Field of the Invention
The present invention relates to a thin film transistor substrate of a liquid crystal display panel and a manufacturing method thereof, and more particularly, to a thin film transistor substrate of a liquid crystal display panel and a manufacturing method thereof which is capable of improving the aperture ratio.
2. Description of the Prior Art
Because of the advantages of low radiation, small size, and low power consumption, liquid crystal display panels have been widely applied to various electronic products, such as notebooks, personal digital assistants, flat televisions, and mobile phones. Generally, a liquid crystal display panel includes a thin film transistor substrate, a color filter substrate, and a liquid crystal layer disposed between the thin film transistor substrate and the color filter substrate. Moreover, the thin film transistor substrate has a plurality of pixel areas defined thereon, and a back light module is further disposed on a side of the liquid crystal display panel to provide back light. Accordingly, through controlling the voltage applying to the liquid crystal layer of each pixel area, corresponding gray scale can be obtained for each pixel area to display images. Furthermore, in order to maintain the voltage to the next frame, storage capacitors are usually disposed in each pixel areas of the thin film transistor substrate.
However, the material of the storage capacitor is an opaque metal layer. The opaque metal layer would block light, decrease the aperture ratio of each pixel area, and further reduce the brightness of the liquid crystal display panel. On the other hand, decease of the area of each storage capacitor electrodes may increase the aperture ratio of each pixel area, but this would lead to deterioration of display quality, such as generation of image flicker, because the voltage of the liquid crystal layer cannot be maintained to the next frame.
SUMMARY OF THE INVENTIONIt is therefore one of the objectives of the present invention to provide a thin film transistor substrate of a liquid crystal display panel and a manufacturing method thereof to solve the problems which the conventional art faces.
In accordance with a preferred embodiment of the present invention, a manufacturing method of a thin film transistor substrate of a liquid crystal display panel includes the following steps. First of all, a substrate is provided. Then, a transparent conducting layer and an opaque conducting layer are formed on the substrate, wherein the opaque conducting layer is disposed on the transparent conducting layer. Thereafter, the transparent conducting layer and the opaque conducting layer are patterned by using a gray-tone mask to form at least one storage capacitor electrode. The storage capacitor electrode includes a patterned transparent conducting layer and a patterned opaque conducting layer, and an area of the transparent conducting layer is larger than an area of the patterned opaque conducting layer. Next, a first insulated layer is formed on the storage capacitor electrode. Then, at least one gate electrode is formed on the substrate. Subsequently, at least one gate insulated layer, a patterned semiconductor layer, a source electrode, a drain electrode, and a second insulated layer are formed sequentially on the gate electrode. Moreover, at least one pixel electrode is formed on the first insulated layer and on the second insulated layer. A part of the pixel electrode overlaps a part of the storage capacitor electrode to form a storage capacitor.
In accordance with a preferred embodiment of the present invention, a thin film transistor substrate of a liquid crystal display panel includes a substrate, a storage capacitor electrode, a first insulated layer, a gate electrode, a gate insulated layer, a patterned semiconductor layer, a source electrode, a drain electrode, a second insulated layer, and a pixel electrode. The storage capacitor electrode is disposed on the substrate. The storage capacitor includes a patterned transparent conducting layer and a patterned opaque conducting layer, the patterned opaque conducting layer is disposed on the transparent conducting layer, and an area of the patterned transparent conducting layer is larger than an area of the patterned opaque conducting layer. The first insulated layer is disposed on the storage capacitor electrode. Also, the gate electrode is disposed on the substrate. The gate insulated layer, the patterned semiconductor layer, the source electrode, the drain electrode, and the second insulated layer are disposed sequentially on the gate electrode. The pixel electrode is disposed on the second insulated layer and on the first insulated layer, and a part of the pixel electrode overlaps a part of the storage capacitor electrode to form a storage capacitor.
According to the thin film transistor substrate of the liquid crystal display panel and a manufacturing method thereof, the patterned transparent conducting layer and the patterned opaque conducting layer can be accomplished by using a gray-tone mask. In comparison with the method of forming the patterned transparent conducting layer and the opaque conducting layer by using the process with two masks, one mask is saved, and process steps are reduced. Also, the electrical difference caused by the misalignment between the patterned transparent conducting layer and the patterned opaque conducting layer is prevented. Moreover, the capacitance of the storage capacitor and the aperture ratio can be both increased by forming the patterned transparent conducting layer with larger area.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
Certain terms are applied throughout the following description and claim to refer to particular components. As those of ordinary skill will appreciate, manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but in function. In the following discussion and in the claims, the terms “include”, “including”, “comprise”, and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”. Moreover, the phrase “electrically connect” includes any direct or indirect means to electrically connect so that if it describe that a first device is electrically connected to a second device in the article, which means, the first device may be directly connected to the second device and also nay be indirectly connected to the second device through other devices or by other methods. Furthermore, it is noticeable that the figures are only used for description and not drawn to scale.
Please refer
As shown in
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As shown in
Then, at least one pixel electrode 19 is formed on the second insulated layer 18 and on the first insulated layer 13. A part of the pixel electrode 19 overlaps a part of the storage capacitor electrode 11 to form a storage capacitor. In this preferred embodiment, the pixel electrode 19 is made of a transparent conducting layer, such as indium tin oxide or zinc oxide, but not limited thereto. It is appreciated that the second insulated layer 18 has at least one contact hole 181, and the pixel electrode 19 is electrically connected to the drain electrode 172 via the contact hole 181. Moreover,
According to the manufacturing method of forming the thin film transistor substrate of the liquid crystal display panel of the first preferred embodiment, the patterned transparent conducting layer 113 and the patterned opaque conducting layer 114 can be accomplished by using the gray-tone mask 20. In comparison with the method of forming the patterned transparent conducting layer 113 and the opaque conducting layer 114 by using the process with two masks, one mask is saved, and process steps are reduced. Also, the electrical difference caused by the misalignment between the patterned transparent conducting layer 113 and the patterned opaque conducting layer 114 is prevented. The storage capacitor electrode 11 includes the patterned transparent conducting layer 113 and the patterned opaque conducting layer 114, and the area of the patterned transparent conducting layer 113 is larger than the area of the patterned opaque conducting layer 114. Consequently, the capacitance of the storage capacitor formed between the storage capacitor electrode 11 and the pixel electrode 19, and the aperture ratio can be both increased by increasing the area of the patterned transparent conducting layer 113, which is optically transmittable.
The thin film transistor substrate of the liquid crystal display panel of the present invention is not limited to the first preferred embodiment mentioned above, and may have other embodiments. In order to compare the difference between the embodiments more easily and to describe briefly, in the following second preferred embodiment, same components are denoted by same numerals. Please refer to
Next, as shown in
In conclusion, the thin film transistor substrate of the liquid crystal display panel of the present invention accomplishes the storage capacitor electrode formed by the patterned transparent conducting layer and the patterned opaque conducting layer by using a gray-tone mask. In comparison with the method of forming the patterned transparent conducting layer and the opaque conducting layer by using the process with two masks, one mask is saved, and process steps are reduced. Also, since the patterned transparent conducting layer and the patterned opaque conducting layer are patterned by the same mask, the electrical difference caused by the misalignment between the patterned transparent conducting layer and the patterned opaque conducting layer is prevented. The storage capacitor electrode includes the patterned transparent conducting layer and the patterned opaque conducting layer, and the area of the patterned transparent conducting layer is larger than the area of the patterned opaque conducting layer. Consequently, the capacitance of the storage capacitor and the aperture ratio can be both increased by increasing the area of the patterned transparent conducting layer with high optical transmittance.
Those skilled in the art will readily observe that numerous modifications and alterations of the structure and method may be made while retaining the teachings of the invention.
Claims
1. A thin film transistor substrate of a liquid crystal display panel, comprising:
- a substrate;
- at least one storage capacitor electrode, disposed on the substrate, the storage capacitor electrode comprising a patterned transparent conducting layer and a patterned opaque conducting layer, wherein the patterned opaque conducting layer is disposed on the pattern transparent conducting layer, and an area of the patterned transparent conducting layer is larger than an area of the patterned opaque conducting layer;
- a first insulated layer disposed on the storage capacitor electrode;
- at least one gate electrode disposed on the substrate;
- at least one gate insulated layer, a patterned semiconductor layer, a source electrode, a drain electrode, and a second insulated layer disposed sequentially on the gate electrode; and
- at least one pixel electrode, disposed on the second insulated layer and on the first insulated layer, wherein a part of the pixel electrode overlaps a part of the storage capacitor electrode to form a storage capacitor.
2. The thin film transistor substrate of the liquid crystal display panel according to claim 1, wherein the gate electrode is disposed on the first insulated layer, the second insulated layer has at least one contact hole, and the pixel electrode is electrically connected to the drain electrode via the contact hole.
3. The thin film transistor substrate of the liquid crystal display panel according to claim 1, wherein the storage capacitor electrode is disposed on the second insulated layer, the first insulated layer and the second insulated have at least one contact hole, and the pixel electrode is electrically connected to the drain electrode via the contact hole.
Type: Application
Filed: Dec 30, 2010
Publication Date: Feb 2, 2012
Inventor: Sheng-Hsiung Hou (Kaohsiung City)
Application Number: 12/981,517
International Classification: H01L 27/32 (20060101);