COATING METHOD FOR LIQUID CRYSTAL ALIGNMENT FILM OF TFT-LCD
A coating method for liquid crystal alignment film of TFT-LCD including: forming a layer of hydrophobic film on a TFT/CF substrate corresponding to a non-display area, the hydrophobic film separates the TFT/CF substrate into a plurality of rectangular opened areas which are separated from each other, each of the rectangular opened areas corresponds to a display area and its outer frame is formed by the hydrophobic film; and coating of a liquid of a material of an alignment film along a boundary of the rectangular opened area. Accordingly, edge waves caused by spreading of drips of the material of the alignment film can be reduced, so that a precision of printing of the alignment film can be controlled effectively.
The present invention relates to a manufacturing technique of liquid crystal display device and more particularly to a coating technique for liquid crystal alignment film of LCD.
BACKGROUND OF THE INVENTIONPI (polyimide) film is a layer of even alignment film on a surface of TFT (Thin Film Transistor) substrate and CF (Color Filter) substrate, it makes liquid crystal molecules to be arranged according to a certain pre-tilt angle in order to control a passing direction of light, and achieve a display purpose by applying an appropriate driving voltage. Currently, there are mainly two coating methods of coating technique for PI film: PI roller coating and PI inkjet.
Referring to
Referring to
U.S. patent number 20060172091 discloses a forming method of alignment film, by forming a layer of hydrophobic film on parts of a surface of a TFT substrate corresponding to a non-display area, and forming a layer of hydrophilic film on parts corresponding to a display area, so that a boundary of the hydrophilic film is limited by the hydrophobic film, and by employing the inkjet printing method, an alignment film is then formed by dripping of a liquid of the material of the alignment film. Such forming method of employing inkjet printing on the areas corresponding to the hydrophilic film is the same as the conventional technique illustrated in
In order to tackle the abovementioned conventional technical problems, the present invention provides a coating method for liquid crystal alignment film of TFT-LCD, by which edge waves of an alignment film caused by inkjet printing can be reduced, and a precision of printing of the alignment film can be controlled effectively.
A technical solution employed by the present invention to tackle the abovementioned technical problems includes providing a coating method for liquid crystal alignment film of TFT-LCD, including:
-
- forming a layer of hydrophobic film on a TFT/CF substrate corresponding to a non-display area, the hydrophobic film separates the TFT/CF substrate into a plurality of rectangular opened areas which are separated from each other, each of the rectangular opened areas corresponds to a display area and its outer frame is formed by the hydrophobic film; and
- coating of a liquid of a material of an alignment film along a boundary of the rectangular opened area.
The coating method of the present invention further including:
Forming a layer of hydrophilic film on the rectangular opened area, the coating of the liquid of the material of the alignment film is performed along a boundary of the hydrophilic film and the hydrophobic film.
Having a same thickness of the hydrophilic film and the hydrophobic film.
Realizing the coating of the liquid of the material of the alignment film by spraying of continuous lines.
Connecting the continuous lines as a rectangle corresponding to the boundary of the rectangular opened area.
The hydrophobic film is formed by coating a layer of hydrophobic polymer on the TFT/CF substrate corresponding to the non-display area.
The hydrophilic film is formed by coating a layer of hydrophilic polymer on the rectangular opened area of the TFT/CF substrate.
The material of the alignment film is polyimide.
Comparing with the conventional techniques and according to the coating method for liquid crystal alignment film of TFT-LCD of the present invention, by forming a layer of hydrophobic film on the surface of the TFT/CF substrate, and performing the coating on the boundary of the rectangular opened area and the hydrophobic film, the edge waves caused by spreading of the drips of the material of the alignment film can be reduced, so that a precision of printing of the alignment film can be controlled effectively.
The present invention will become more fully understood by reference to the following detailed description thereof when read in conjunction with the attached drawings.
Referring to
In the coating method of the present invention, it further includes: forming a layer of hydrophilic film on the rectangular opened area, the coating of the liquid of the material of the alignment film is performed along the boundary 11 of the hydrophilic film and the hydrophobic film 10. Preferably, having a same thickness of the hydrophilic film and the hydrophobic film 10. Wherein, the hydrophobic film 10 is formed by coating a layer of hydrophobic polymer on the TFT/CF substrate 1 corresponding to the non-display area. The hydrophilic film is formed by coating a layer of hydrophilic polymer on the rectangular opened area of the TFT/CF substrate 1.
In the coating method of the present invention, the coating of the liquid of the material of the alignment film can be realized by spraying of continuous lines. The continuous lines are connected as a rectangle corresponding to the boundary 11 of the rectangular opened area, in other words, a shape of the coating of the liquid of the material of the alignment film is a rectangle, and is not an array composed of dots as shown in
Referring to
Referring to
Comparing with the conventional techniques and according to the coating method for liquid crystal alignment film of TFT-LCD of the present invention, by forming a layer of hydrophobic film on the surface of the TFT/CF substrate, and performing the coating on the boundary of the rectangular opened area and the hydrophobic film, a PI film with excellent straightness of edges can be manufactured.
Note that the specifications relating to the above embodiments should be construed as exemplary rather than as limitative of the present invention, with many variations and modifications being readily attainable by a person of average skill in the art without departing from the spirit or scope thereof as defined by the appended claims and their legal equivalents.
Claims
1. A coating method for a liquid crystal alignment film of a TFT-LCD, including:
- forming a layer of hydrophobic film on a TFT/CF substrate corresponding to a non-display area, the layers of hydrophobic film separating the TFT/CF substrate into a plurality of rectangular opened areas being separated from each other, wherein each of the plurality of rectangular opened areas corresponds to a display area that has an outer frame that is formed by the layer of hydrophobic film; and
- coating of a liquid of a material of an alignment film along a boundary of each area of the plurality of rectangular opened areas, wherein the coating of the liquid of the material of the alignment film is performed by spraying of continuous lines, and the continuous lines are connected as a rectangle corresponding to the boundary of each area of the plurality of rectangular opened areas.
2. The coating method as claimed in claim 1, further comprising:
- forming a layer of hydrophilic film on the rectangular opened area, the coating of the liquid of the material of the alignment film being performed along a boundary of the hydrophilic film and the hydrophobic film.
3. The coating method as claimed in claim 2, wherein having a same thickness of the hydrophilic film and the hydrophobic film.
4. (canceled)
5. (canceled)
6. The coating method as claimed in claim 1, wherein the hydrophobic film is formed by coating a layer of hydrophobic polymer on the TFT/CF substrate corresponding to the non-display area.
7. The coating method as claimed in claim 2, wherein the hydrophilic film is formed by coating a layer of hydrophilic polymer on the plurality of rectangular opened areas of the TFT/CF substrate.
8. The coating method as claimed in claim 1, wherein the material of the alignment film is polyimide.
Type: Application
Filed: Dec 8, 2011
Publication Date: May 16, 2013
Inventors: Mei-Na Zhu (Shenzhen), Jian-Jun Zhao (Shenzhen), Hsiang-Yin Shih (Shenzhen)
Application Number: 13/379,808
International Classification: H01L 33/08 (20100101);