This application claims the priority benefit of Taiwan application serial no. 99142396, filed on Dec. 6, 2010. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
1. Field of the Invention
The invention relates to a pixel array substrate and a method of fabricating the same. More particularly, the invention relates to a pixel array substrate applicable to a display device and a method of fabricating the pixel array substrate.
2. Description of Related Art
Recently, thin film transistor liquid crystal display (TFT-LCD) panels have been developed toward high contrast ratio, no gray scale inversion, high brightness, high color saturation, fast response speed, and wide viewing angle. At this current stage, LCD panels featuring the wide viewing angle include twisted nematic (TN) LCD panels equipped with wide viewing films, in-plane switching (IPS) LCD panels, fringe field switching (FFS) LCD panels, and multi-domain vertical alignment (MVA) LCD panels.
For instance, the FFS LCD panels are characterized by wide viewing angle and low color shift. However, in a conventional FFS LCD panel, the electric field between the pixel electrodes and the common electrode is insufficient, such that the display luminance of the convention FFS LCD panel is not high enough, which reduces the display quality of the FFS LCD panel. Accordingly, how to improve both the display luminance and the display quality of the FFS LCD panel is one of the issues to be resolved by researchers.
The invention is directed to a pixel array substrate that can improve the display luminance of a FFS display panel.
The invention is further directed to a display panel that has favorable display aperture ratio and favorable display quality.
The invention is further directed to a method of fabricating a pixel array substrate. By applying this method, the pixel array substrate that improves the transmittance of an FFS display panel can be fabricated.
In an embodiment of the invention, a pixel array substrate includes a substrate, a plurality of scan lines, a plurality of data lines, a plurality of active devices, a passivation layer, a common electrode, a dielectric layer, and a plurality of pixel electrodes. The substrate has a display area and a peripheral area. The peripheral area is substantially connected to the display area. The scan lines and the data lines are configured in the display area of the substrate. The scan lines and the data lines are intersected. The active devices are configured in the display area of the substrate and electrically connected to the scan lines and the data lines. The passivation layer covers the active devices. The common electrode is configured on the passivation layer and located at least in the display area. The dielectric layer covers the common electrode. The pixel electrodes are configured on the dielectric layer, and each of the pixel electrodes is electrically connected to one of the active devices. Each of the pixel electrodes has a plurality of slits, and a portion of the common electrode located under the slits is not shaded by the pixel electrodes.
In an embodiment of the invention, a display panel includes the aforesaid pixel array substrate, an opposite substrate, and a display medium layer. The pixel array substrate is opposite to the opposite substrate, and the display medium layer is configured between the pixel array substrate and the opposite substrate.
In an embodiment of the invention, a method of fabricating a pixel array substrate includes following steps. A substrate on which a plurality of scan lines, a plurality of data lines, a plurality of active devices, and a plurality of common electrode lines are formed is provided. The substrate has a display area and a peripheral area connected thereto. The scan lines and the data lines are intersected. Each of the active devices is electrically connected to a corresponding one of the scan lines and a corresponding one of the data lines. The common electrode lines and the data lines are intersected. A passivation layer is formed, and the passivation layer covers the active devices and the common electrode lines. A plurality of first openings are formed in the passivation layer that is located above the common electrode lines, and the first openings expose the common electrode lines. A common electrode is formed on the passivation layer. The common electrode is located in the display area and fills the first openings, such that the common electrode is electrically connected to the common electrode lines. A dielectric layer is formed on the common electrode. A plurality of second openings are formed in the passivation layer and the dielectric layer that are located above the active devices. The second openings expose the active devices. A plurality of pixel electrodes are formed on the dielectric layer. The pixel electrodes are located in the display area of the substrate, and the second openings corresponding to the pixel electrodes are filled with the corresponding pixel electrodes, such that the pixel electrodes are electrically connected to the corresponding active devices. Here, each of the pixel electrodes has a plurality of slits, and a portion of the common electrode located under the slits is not shaded by the pixel electrodes.
In an embodiment of the invention, a method of fabricating a pixel array substrate includes following steps. A substrate having a display area and a peripheral area is provided. The peripheral area is substantially connected to the display area on which a plurality of scan lines, a plurality of data lines, and a plurality of active devices are formed. The scan lines and the data lines are intersected. Each of the active devices is electrically connected to a corresponding one of the scan lines and a corresponding one of the data lines. The peripheral area of the substrate has a peripheral circuit formed thereon. A passivation layer is formed, and the passivation layer covers the active devices and the peripheral circuit. A third opening is formed in the passivation layer that is located above the peripheral circuit, and the third opening exposes the peripheral circuit. A common electrode is formed on the passivation layer, and the common electrode is located in both the peripheral area and the display area. The third opening is filled with a portion of the common electrode located in the peripheral area, such that the common electrode is electrically connected to the peripheral circuit. A dielectric layer is formed on the common electrode. A plurality of fourth openings are formed in the passivation layer and the dielectric layer that are located above the active devices, and the fourth openings expose the active devices. A plurality of pixel electrodes are formed on the dielectric layer. The fourth openings corresponding to the pixel electrodes are filled with the corresponding pixel electrodes, such that the pixel electrodes are electrically connected to the active devices corresponding thereto. Each of the pixel electrodes has a plurality of slits, and a portion of the common electrode located under the slits is not shaded by the pixel electrodes.
Based on the above, one dielectric layer is sandwiched by the pixel electrodes and the common electrode in a direction perpendicular to the surface of the substrate in the pixel array substrate described in an embodiment of the invention. By contrast, a plurality of insulating layers are sandwiched by the pixel electrodes and the common electrode in the conventional pixel array substrate. Namely, in the pixel array substrate described in an embodiment of the invention, the distance between the pixel electrodes and the common electrode is short, such that the electric field between the pixel electrodes and the common electrode is significant. As such, the display medium in the display panel that has the pixel array substrate can be effectively driven by the display panel, and thereby the transmittance of the display panel can be effectively improved.
In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanying figures are described in detail below.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
With reference to
A plurality of scan lines SL and a plurality of common electrode lines CL are formed on the display area R1 of the substrate 102. According to this embodiment, an extension direction of the common electrode lines CL is substantially parallel to an extension direction of the scan lines SL. In consideration of conductivity, the scan lines SL and the common electrode lines CL are normally made of metal materials. However, the invention is not limited thereto. In other embodiments of the invention, the scan lines SL and the common electrode lines CL can also be made of other conductive materials. For instance, the scan lines SL and the common electrode lines CL can be made of an alloy, metal nitride, metal oxide, metal oxynitride, or a stacked layer containing metal materials and other conductive materials.
An insulating layer GI is formed on the substrate 102, and the insulating layer GI covers the scan lines SL and the common electrode lines CL. The insulating layer GI can be made of an inorganic insulating material (e.g., silicon oxide, silicon nitride, silicon oxynitride, or a stacked layer containing at least two of the aforesaid materials), an organic insulating material, or a combination thereof.
Parts of the scan lines SL serve as gates G, and channel layers CH are formed on the gates G. Data lines DL and drains D are simultaneously formed on the channel layers CH and the insulating layer GI. Here, the data lines DL and the scan lines SL are intersected. Namely, an extension direction of the data lines DL and the extension direction of the scan lines SL are not parallel. Preferably, the extension direction of the data lines DL is perpendicular to the extension direction of the scan lines SL. Additionally, in this embodiment, parts of the data lines DL that are overlapped with the channel layers CH serve as the sources S, and the active devices T are then formed. Namely, the active devices T are electrically connected to the scan lines SL and the data lines DL. The active devices T described above are bottom-gate TFTs, for instance, which should not be construed as a limitation to the invention. In other embodiments, the active devices T can also be top-gate TFTs, multi-gate TFTs, and so on. During fabrication of the scan lines SL, the gates G can be parts of the scan lines SL or formed by an extending portion of the scan lines SL, which should not be construed as a limitation to the invention.
The data lines DL intersect the scan lines SL and the common electrode lines CL. In other words, the extension direction of the data lines DL is not parallel to the extension direction of the scan lines SL and the extension direction of the common electrode lines CL. In an embodiment of the invention, the extension direction of the data lines DL is perpendicular to the extension direction of the scan lines SL and the extension direction of the common electrode lines CL, for instance. A material of the data lines DL is similar to that of the scan lines SL and that of the common electrode lines CL, and thus no further descriptions are provided herein.
With reference to
As indicated in
With reference to
With reference to
Particularly, the common electrode 106 is electrically insulated from the pixel electrodes PE by the dielectric layer 108. An electric field is generated between the pixel electrodes PE and the common electrode 106 because of the slits g that expose the common electrode 106.
It should be mentioned that one dielectric layer 108 is sandwiched by the pixel electrodes PE and the common electrode 106 in this embodiment. As such, in a direction perpendicular to the surface of the substrate 102, the distance between the pixel electrodes PE and the common electrode 106 is substantially equal to the thickness of the dielectric layer 108. Consequently, the electric field between the pixel electrodes PE and the common electrode 106 can be significantly increased.
In addition, according to this embodiment, a portion of the data lines DL can be overlapped with a portion of the pixel electrodes PE, so as to increase the aperture ratio of the pixel array substrate 100. To be more specific, the passivation layer 104, the common electrode 106, and the dielectric layer 108 are sandwiched by a portion of the data lines DL and a portion of the pixel electrodes PE, such that the distance between the data lines DL and the pixel electrodes PE is rather large. Thereby, the capacitive coupling effect occurring between the data lines DL and the pixel electrodes PE is not significant, and thus a portion of the data lines DL can be overlapped with a portion of the pixel electrodes PE to increase the aperture ratio of the pixel array substrate 100.
The pixel array substrate 100A of this embodiment is similar to the pixel array substrate 100 of the first embodiment. Therefore, the difference therebetween is described hereinafter, while the similarity therebetween is omitted.
With reference to
An insulating layer GI is formed on the display area R1 and the peripheral area R2 of the substrate 102, and the insulating layer GI covers the scan lines SL and the peripheral circuit L. Channel layers CH are formed on a portion of the scan lines SL, and the portion of the scan lines SL can serve as gates G. Data lines DL are formed on the channel layers CH and the insulating layer GI. Here, a portion of the data lines DL that is overlapped with the channel layers CH serves as sources S. Meanwhile, drains D are formed on the channel layers CH, so as to form active devices T. Namely, the active devices T are electrically connected to the scan lines SL and the data lines DL. The active devices T described above are bottom-gate TFTs, for instance, which should not be construed as a limitation to the invention. In other embodiments, the active devices T can also be top-gate TFTs, multi-gate TFTs, and so on.
In this embodiment, the data lines DL and the scan lines SL are intersected. That is to say, the extension direction of the data lines DL is not parallel to the extension direction of the scan lines SL. According to this embodiment, the extension direction of the data lines DL is perpendicular to the extension direction of the scan lines SL, for instance.
With reference to
As indicated in
With reference to
With reference to
Note that the pixel array substrate 100A of this embodiment does not include the common electrode lines CL configured in the display area R1. Generally, the common electrode lines CL are made of an opaque conductive material, e.g., metal, so as to ensure that the signal transmission quality is favorable. Consequently, the pixel array substrate 100A of this embodiment not only has the advantages of the pixel array substrate 100 described in the first embodiment but also has the increased aperture ratio.
In light of the foregoing, one dielectric layer is sandwiched by the pixel electrodes and the common electrode in a direction perpendicular to the surface of the substrate in the pixel array substrate described in the embodiments of the invention. By contrast, a plurality of insulating layers are sandwiched by the pixel electrodes and the common electrode in the conventional pixel array substrate. Namely, in the pixel array substrate described in the embodiments of the invention, the distance between the pixel electrodes and the common electrode is short, such that the electric field between the pixel electrodes and the common electrode is significant. As such, the display medium in the display panel that has the pixel array substrate described in the embodiments of the invention can be effectively driven by the display panel, and thereby the driving voltage of the display panel can be effectively reduced.
Moreover, in the pixel array substrate described in the embodiments of the invention, the common electrode has a plurality of openings, and each of the openings exposes one of the active devices and one of the scan lines electrically connected to the active device. Thereby, the parasitic capacitance between the common electrode and the scan lines and between the common electrode and the active devices can be effectively reduced, and issues of signal delay and large driving load can be resolved.
On the other hand, a plurality of insulating layers and a common electrode layer are sandwiched by the pixel electrodes and the data lines in the pixel array substrate of the invention, such that the capacitive coupling effect between the data lines and the pixel electrodes is insignificant. As a result, the pixel electrodes and the data lines can be partially overlapped, which leads to an increase in the aperture ratio of the pixel array substrate.
Although the invention has been described with reference to the above embodiments, it will be apparent to one of the ordinary skill in the art that modifications to the described embodiment may be made without departing from the spirit of the invention. Accordingly, the scope of the invention will be defined by the attached claims not by the above detailed descriptions.
Number | Date | Country | Kind |
---|---|---|---|
99142396 | Dec 2010 | TW | national |