TFT substrate and liquid crystal display device having the same comprising patterns disposed at different heights
View Patent ↗An LCD device includes a first substrate having a first base substrate, patterns disposed at different heights with respect to the first base substrate, and an insulation layer formed on the first base substrate and the patterns. The insulation layer has raised portions corresponding to the patterns. A side of the raised portions forms an inclination angle of no more than about 45° when a height of the raised portions is more than about 3000 angstroms, the side of the raised portions forms an inclination angle of no more than about 50° when a height of the raised portions is in a range of about 2000 angstroms to about 3000 angstroms, and the side of the raised portions forms an inclination angle of no more than about 90° when a height of the raised portions is more than about 2000 angstroms. Therefore, light leakage may be minimized.
1. A thin film transistor (TFT) substrate, comprising:
a substrate;
a plurality of gate lines formed on the substrate, the gate lines extending in a first direction;
a plurality of data lines formed on the substrate, the data lines extending in a second direction that is substantially perpendicular to the first direction;
a plurality of pixel electrodes, each of the pixel electrodes being electrically connected to a TFT that is electrically connected to a selected gate line and a selected data line;
a protection layer formed on the substrate such that the protection layer covers the gate lines and data lines; and
a pattern disposed in a pixel region of the substrate to induce a stepped portion of the protection layer, a longitudinal direction of the pattern forming an angle of about 30 degrees to about 60 degrees with respect to one of the first and second directions;
wherein if a thickness of the pattern is thicker than about 3000 angstroms, then a side of the protection layer on the pattern forms an inclination angle of no more than about 45 degrees, if a thickness of the pattern is in a range of about 2000 angstroms to about 3000 angstroms, then the side of the protection layer on the pattern forms an inclination angle of no more than about 50 degrees, and if a thickness of the pattern is less than about 2000 angstroms, then the side of the protection layer on the pattern forms an inclination angle of no more than about 90 degrees.
2. The TFT substrate of claim 1 , wherein the pixel electrode comprises at least one opening portion disposed over the pattern.
3. The TFT substrate of claim 2 , wherein a width of the pattern is substantially smaller than a width of the opening portion of the pixel electrode.
4. The TFT substrate of claim 1 , wherein the data line comprises a bent portion, so that the pixel region has a chevron-shape.
5. The TFT substrate of claim 1 , wherein the protection layer comprises silicon nitride.
6. The TFT substrate of claim 1 , wherein the pattern comprises at least one layer including aluminum or aluminum alloy.
7. The TFT substrate of claim 1 , wherein the pattern comprises molybdenum, molybdenum alloy or chromium.
8. The TFT substrate of claim 1 , wherein the pattern and the data lines are formed from a single layer.
9. The TFT substrate of claim 1 , wherein a first voltage is applied to the pattern and the pixel electrode.
10. The TFT substrate of claim 1 , further comprising a floating pixel electrode that is electrically isolated from the pixel electrode.
11. The TFT substrate of claim 1 , further comprising an alignment layer on the protection layer, wherein if the thickness of the pattern is thicker than about 3000 angstroms, then a side of the alignment layer on the pattern forms an inclination angle of no more than about 45 degrees, if the thickness of the pattern is in the range of about 2000 angstroms to about 3000 angstroms, then the side of the alignment layer on the pattern forms an inclination angle of no more than about 50 degrees, and if the thickness of the pattern is less than about 2000 angstroms, then the side of the alignment layer on the pattern forms an inclination angle of no more than about 90 degrees.
12. A thin film transistor (TFT) substrate, comprising:
a substrate;
a plurality of gate lines formed on the substrate, the gate lines extending in a first direction;
a plurality of data lines formed on the substrate, the data lines extending in a second direction that is substantially perpendicular to the first direction;
a plurality of pixel electrodes, each of the pixel electrodes being electrically connected to a TFT that is electrically connected to a selected gate line and a selected data line;
an alignment layer formed on the substrate such that the alignment layer covers the gate lines and data lines; and
a pattern disposed in a pixel region of the substrate to induce a stepped portion of the alignment layer, a longitudinal direction of the pattern forming an angle of about 30 degrees to about 60 degrees with respect to one of the first and second directions;
wherein if a thickness of the pattern is thicker than about 3000 angstroms, then a side of the alignment layer on the pattern forms an inclination angle of no more than about 45 degrees, if a thickness of the pattern is in a range of about 2000 angstroms to about 3000 angstroms, then the side of the alignment layer on the pattern forms an inclination angle of no more than about 50 degrees, and if a thickness of the pattern is less than about 2000 angstroms, then the side of the alignment layer on the pattern forms an inclination angle of no more than about 90 degrees.
13. A liquid crystal display (LCD) device comprising:
an upper substrate;
a polarization plate having a transmission axis;
a lower substrate facing the upper substrate and disposed on the polarization plate, the lower substrate comprising:
a plurality of gate lines extending in a first direction;
a plurality of data lines extending in a second direction that is substantially perpendicular to the first direction;
a plurality of pixel electrodes, each of the pixel electrodes being electrically connected to a TFT that is electrically connected to a selected gate line and a selected data line;
a protection layer formed on the substrate such that the protection layer covers the gate lines and the data lines; and
a pattern disposed in a pixel region of the substrate to induce a stepped portion of the protection layer, a longitudinal direction of the pattern forming an angle of about 30 degrees to about 60 degrees with respect to the polarization axis;
wherein if a thickness of the pattern is thicker than about 3000 angstroms, a side of the protection layer on the pattern forms an inclination angle of no more than about 45 degrees, if a thickness of the pattern is in a range of about 2000 angstroms to about 3000 angstroms, then the side of the protection layer on the pattern forms an inclination angle of no more than about 50 degrees, and if a thickness of the pattern is less than about 2000 angstroms, then the side of the protection layer on the pattern forming an inclination angle of no more than about 90 degrees; and
a liquid crystal layer disposed between the upper and lower substrates.
14. The LCD device of claim 13 , further comprising an alignment layer on the protection layer, wherein if the thickness of the pattern is thicker than about 3000 angstroms, then a side of the alignment layer on the pattern forms an inclination angle of no more than about 45 degrees, if the thickness of the pattern is in the range of about 2000 angstroms to about 3000 angstroms, then the side of the alignment layer on the pattern forms an inclination angle of no more than about 50 degrees, and if the thickness of the pattern is less than about 2000 angstroms, then the side of the alignment layer on the pattern forms an inclination angle of no more than about 90 degrees.
15. A liquid crystal display (LCD) device comprising:
an upper substrate;
a polarization plate having a transmission axis;
a lower substrate facing the upper substrate and disposed on the polarization plate, the lower substrate comprising:
a plurality of gate lines extending in a first direction;
a plurality of data lines extending in a second direction that is substantially perpendicular to the first direction;
a plurality of pixel electrodes, each of the pixel electrodes being electrically connected to a TFT that is electrically connected to a selected gate line and a selected data line;
an alignment layer formed on the substrate such that the alignment layer covers the gate lines and the data lines; and
a pattern disposed in a pixel region of the substrate to induce a stepped portion of the alignment layer, a longitudinal direction of the pattern forming an angle of about 30 degrees to about 60 degrees with respect to the polarization axis;
wherein if a thickness of the pattern is thicker than about 3000 angstroms, a side of the alignment layer on the pattern forms an inclination angle of no more than about 45 degrees, if a thickness of the pattern is in a range of about 2000 angstroms to about 3000 angstroms, then the side of the alignment layer on the pattern forms an inclination angle of no more than about 50 degrees, and if a thickness of the pattern is less than about 2000 angstroms, then the side of the alignment layer on the pattern forming an inclination angle of no more than about 90 degrees; and
a liquid crystal layer disposed between the upper and lower substrates.