In-plane switching mode liquid crystal display device and method of fabrication thereof
View Patent ↗An in-plane switching mode liquid crystal display device includes, among other features, a gate line, a common line, a data line, a thin film transistor connected to the gate line and the data line, a drain electrode, a first insulating layer to cover the entire surface of a first substrate except a pixel region and portions of the drain electrode and the common line; a first pixel line layer connected to the drain electrode and on a side of the first insulating layer, a first common line layer connected to the common line and on a side of the first insulating layer, a second insulating layer in a region that is not covered by the first insulating layer, a second pixel line layer on the second insulating layer and connected to the first pixel line layer, and a second common line layer on the second insulating layer and connected on the first common line layer.
1. An in-plane switching mode liquid crystal display device, comprising:
a gate line on an inner surface of a first substrate;
a common line substantially parallel to and spaced apart from the gate line;
a data line crossing the gate line to define a pixel region;
a thin film transistor connected to the gate line and the data line, the thin film transistor including a gate electrode connected to the gate line, a source electrode connected to the data line, and a drain electrode spaced apart from the source electrode;
a first insulating layer to cover an entire surface of the first substrate except the pixel region and portions of the drain electrode and the common line;
a first pixel line layer connected to the drain electrode and on a side of the first insulating layer, the first pixel line layer overlapping a portion of an upper surface of the first insulating layer;
a first common line layer connected to the common line and on a side of the first insulating layer, the first common line layer overlapping a portion of an upper surface of the first insulating layer;
a second insulating layer in a region that is not covered by the first insulating layer, the second insulating layer in the region including the pixel region;
a second pixel line layer connected to the first pixel line layer, the second pixel line layer on the second insulating layer, the first and second pixel line layers forming a pixel line;
a plurality of pixel electrodes extending from the second pixel line layer in the pixel region, wherein the plurality of pixel electrodes is substantially parallel to the data line;
a second common line layer connected on the first common line layer, the second common line layer on the second insulating layer, the first and second common line layers forming an auxiliary common line;
a plurality of common electrodes extending from the second common line layer in the pixel region, wherein the plurality of common electrodes is substantially parallel to the pixel electrodes;
a second substrate facing and spaced apart from the first substrate; and
a liquid crystal layer between the first and second substrates.
2. The device according to claim 1 , wherein the first and second insulating layers include an insulating material having a high resistance value.
3. The device according to claim 2 , wherein the first insulating layer includes an insulating material having a relative dielectric constant within a maximum value of about 11.0.
4. The device according to claim 3 , wherein the first insulating layer is selected from one of silicon nitride (SiNx), benzocyclobutene (BCB), and photo acryl.
5. The device according to claim 2 , wherein the second insulating layer is selected from a insulating material having a resistance value within a minimum value of about 1×10 11 Ω·cm.
6. The device according to claim 5 , wherein the insulating material is benzocyclobutene (BCB).
7. The device according to claim 2 , wherein at least one common electrode in an outermost portion of the common electrodes is closer to the data line than at least one pixel electrode in an outermost portion of the pixel electrodes for each pixel region, wherein the at least one common electrode overlaps a portion of the data line.
8. The device according to claim 1 , wherein surfaces between the first and second insulating layers have a same texture.
9. The device according to claim 1 , wherein the first insulating layer includes an insulating material having light protection.
10. The device according to claim 9 , wherein the second insulating layer is a color filter layer.
11. The device according to claim 10 , wherein the color filter layer includes red, green and blue color filters, wherein the red, green and blue color filters are in each pixel region.
12. The device according to claim 1 , wherein the common electrodes and the pixel electrodes include the same material.
13. The device according to claim 1 , wherein the gate line and the common line include the same material.
14. The device according to claim 13 , further comprising a gate insulating layer on an entire surface of the first substrate including the gate line and the common line, wherein the gate insulating layer directly contacts the gate line and the common line.
15. The device according to claim 14 , wherein the gate insulating layer includes a common line contact hole exposing a portion of the common line, wherein the first common line layer is connected to the common line via the common line contact hole.
16. The device according to claim 14 , further comprising an active layer and an ohmic contact layer on the gate insulating layer over the gate electrode, the active layer and the ohmic contact layer forming a semiconductive layer, and the thin film transistor includes the semiconductive layer.
17. The device according to claim 1 , wherein the first pixel line layer and the first common line layer are selected from a conductive material having a resistance value within a maximum value of about 1×10 6 Ω·cm.
18. The device according to claim 17 , wherein the conductive material is selected from one of a single material including copper (Cu), chromium (Cr), molybdenum (Mo), titanium (Ti), tantalum (Ta), tungsten (W), and indium tin oxide (ITO), and one of an alloy material including AlTa, AlSi, AlTi, AlNd, CuCr, CuMg, MoW, and MoTa.
19. The device according to claim 1 , wherein each of the first pixel line layer and the first common line layer are isolated.
20. The device according to claim 1 , wherein the second pixel line layer, the pixel electrodes, the second common line layer, and the common electrodes include transparent conductive materials.
21. The device according to claim 1 , wherein the first pixel line layer is electrically connected to the drain electrode by side contact.
22. The device according to claim 1 , further comprising a black matrix on an inner surface of the second substrate, the black matrix including an open portion in the pixel region.
23. The device according to claim 22 , further comprising a color filter layer in the open portion of the black matrix over the second substrate, the color filter layer including red, green and blue color filters, wherein the red, green and blue color filters are in each pixel region.
24. The device according to claim 23 , further comprising an overcoat layer on an entire surface of the color filter layer and the black matrix.
25. A method of fabricating an in-plane switching mode liquid crystal display device, comprising:
forming a gate line and a gate electrode connected to the gate line on a first substrate;
forming a common line substantially parallel to and spaced apart from the gate line;
forming a gate insulating layer on an entire surface of the first substrate including the gate line, the gate electrode, and the common line;
forming a data line crossing the gate line to define a pixel region, a source electrode connected to the data line, and drain electrode spaced apart from the source electrode;
forming a first insulating layer to cover the entire surface of the first substrate except the pixel region and portions of the drain electrode and the common line;
forming a first pixel line layer connected to the drain electrode and on a side of the first insulating layer, the first pixel line layer overlapping a portion of an upper surface of the first insulating layer;
forming a first common line layer connected to the common line and on a side of the first insulating layer, the first common line layer overlapping a portion of an upper surface of the first insulating layer;
forming a second insulating layer in a region that is not covered by the first insulating layer, the second insulating layer in the region including the pixel region;
forming a second pixel line layer connected to the first pixel line layer, the second pixel line layer on the second insulating layer, the first and second pixel line layers forming a pixel line;
forming a plurality of pixel electrodes extending from the second pixel line layer and substantially parallel to the data line, the plurality of pixel electrodes being in the pixel region;
forming a second common line layer connected on the first common line layer, the second common line layer on the second insulating layer, the first and second common line layers forming an auxiliary common line;
forming a plurality of common electrodes extending from the second common line layer in the pixel region, wherein the plurality of common electrodes are substantially parallel to the pixel electrodes;
forming a second substrate facing and spaced apart from the first substrate;
attaching the first substrate and a second substrate; and
forming a liquid crystal layer between the first and second substrates.
26. The method according to claim 25 , wherein the first and second insulating layers include a insulating material having a high resistance value.
27. The method according to claim 26 , wherein the first insulating layer includes an insulating material having a relative dielectric constant within a maximum value of about 11.0.
28. The method according to claim 26 , wherein the second insulating layer is selected from a insulating material having a resistance value within a minimum value of about 1×10 11 Ω·cm.
29. The device according to claim 28 , wherein the insulating material is benzocyclobutene (BCB).
30. The method according to claim 25 , wherein the first insulating layer includes an insulating material having light protection.
31. The method according to claim 30 , wherein the second insulating layer is a color filter layer.
32. The method according to claim 31 , wherein the color filter layer includes red, green and blue color filters, wherein each of the red, green and blue color filters are in each pixel region.
33. The method according to claim 25 , wherein forming the common electrodes and forming the pixel electrodes are the same process and includes the same material.
34. The method according to claim 25 , wherein forming the gate line and forming the common line are the same process and includes the same material.
35. The method according to claim 25 , wherein the gate insulating layer includes a common line contact hole exposing a portion of the common line wherein the first common line layer is connected to the common line via the common line contact hole.
36. The method according to claim 25 , further comprising forming an active layer and an ohmic contact layer on the gate insulating layer over the gate electrode, the active layer and the ohmic contact layer forming a semiconductive layer, and the gate electrode, the semiconductive layer, the source electrode and the drain electrode form a thin film transistor.
37. The method according to claim 25 , wherein the first pixel line layer and the first common line layer are selected from a conductive material having a resistance value within a maximum value of about 1×10 6 Ω·cm.
38. The method according to claim 37 , wherein the conductive material is selected from one of a single material including copper (Cu), chromium (Cr), molybdenum (Mo), titanium (Ti), tantalum (Ta), tungsten (W), and indium tin oxide (ITO), and one of an alloy material including AlTa, AlSi, AlTi, AlNd, CuCr, CuMg, MoW, and MoTa.
39. The method according to claim 25 , wherein each of the first pixel line layer and the first common line layer are isolated.
40. The method according to claim 25 , wherein the second pixel line layer, the pixel electrodes, the second common line layer, and the common electrodes include transparent conductive materials.
41. The method according to claim 25 , wherein at least one common electrode in an outermost portion of the common electrodes is closer to the data line than at least one pixel electrode in an outermost portion of the pixel electrodes for each pixel region, wherein the at least one common electrode overlaps the data line.
42. The method according to claim 25 , wherein the first pixel line layer is electrically connected to the drain electrode by side contact type.
43. The device according to claim 25 , further comprising forming a black matrix on the second substrate, the black matrix including an open portion in the pixel region.
44. The method according to claim 43 , further comprising forming a color filter layer in the open portion of the black matrix over the second substrate, the color filter layer including red, green and blue color filters, wherein the red, green and blue color filters are in each pixel region.
45. The method according to claim 44 , further comprising forming an overcoat layer on an entire surface of the color filter layer and the black matrix.