Active matrix organic light emitting display (OLED) and method of fabrication
View Patent ↗An organic light emitting display includes a substrate having a pixel driving circuit region and an opening region. A thin film transistor having source/drain electrodes is positioned on the pixel driving circuit region of the substrate. A passivation insulating layer is positioned on the source/drain electrodes to have a via hole for exposing one of the source/drain electrodes. A pixel electrode is positioned on a bottom surface of the via hole and in contact with the exposed source/drain electrode, and extends onto the passivation insulating layer. A first photosensitive organic insulating layer is positioned within the via hole in which the pixel electrode is formed to fill the via hole and to expose a portion of the pixel electrode around the via hole. An organic emission layer is positioned on the exposed pixel electrode.
1. A display, comprising:
a substrate including a pixel driving circuit region and an opening region;
a thin film transistor positioned on top of the pixel driving circuit region and having source/drain electrodes;
an insulating layer positioned on top of the source/drain electrodes having a via hole exposing one of the source/drain electrodes and having a groove above and extending below an uppermost top surface of another of the source/drain electrodes;
a pixel electrode contacting the exposed source/drain electrode within the via hole and extending directly onto a top of the insulating layer to physically contact the insulating layer and to completely encircle the via hole, the insulating layer being between the source/drain electrodes and the pixel electrode;
a first photosensitive layer pattern positioned within the via hole in which the pixel electrode is arranged and exposing a portion of the pixel electrode extending onto a top of the insulating layer and physically contacting the insulating layer and adjacent to the via hole,
a top surface of the first photosensitive layer being no higher than the portion of the pixel electrode extending directly onto a top of the insulating layer;
a second photosensitive layer pattern filling said groove in said insulating layer; and
an organic emission layer positioned on top of the exposed pixel electrode and on an edge of the pixel electrode encircling the via hole to directly contact the edge of the pixel electrode encircling the via hole,
wherein an upper surface of the via hole, an upper surface of said groove and an upper surface of said second photosensitive layer pattern are all in a same plane.
2. The display as claimed in claim 1 , wherein the first photosensitive layer pattern comprises one of an acrylic-based polymer and an imide-based polymer.
3. The display as claimed in claim 1 , wherein the insulating layer comprises an inorganic layer.
4. The display as claimed in claim 3 , wherein the inorganic layer comprises a silicon nitride layer.
5. The display as claimed in claim 1 , wherein the first photosensitive layer pattern exposes the portion of the pixel electrode around the via hole.
6. The display as claimed in claim 1 , wherein the second photosensitive layer pattern comprises one of an acrylic-based polymer and an imide-based polymer.
7. The display as claimed in claim 1 , wherein the pixel electrode comprises one of Indium Tin Oxide (ITO) and Indium Zinc Oxide (IZO).
8. The display as claimed in claim 1 , wherein the pixel electrode includes a tapered edge.
9. The display as claimed in claim 8 , wherein the tapered edge of the pixel electrode includes a taper angle less than or equal to 20 degrees with respect to a plane parallel to the substrate.