Patent NL-1025135-C2 (NL)
Title: Active matrix organic light emitting display, has sub TFT's in controlling TFT array connected to switching TFT, power row and electrodes
Inventor: PARK JAE-YONG
IPC: H05B33/00
Filed: 2003-12-24
Granted: 2005-08-30
Abstract: The display comprises a substrate with a gate row, a data row intersecting with the gate row and a power row intersecting with the gate row and electrically connected to sub-TFT's (Thin Film Transistors) in a switching TFT next to the gate row-data row intersection point. The sub-TFT's are connected in parallel to the switching TFT via a gate base. A first electrode above the controlling TFT array is in contact with the sub-TFT's, an organic electroluminescent layer is provided on top of the first electrode and a second electrode comprising a transparent material is provided on top of the organic layer. Independent claims are also included for the following: Method for producing this first display; Second active matrix organic light emitting display; and Method for producing this second display. The production of the first display comprises the following steps:forming a metal layer on a substrate; (a) creating a pattern in the metal layer to form a gate line, a switching gate electrode in the switching region, a gate base in the pixel region and controlling gate electrodes in the control region; (b)forming a first insulating layer on the substrate in order to cover the gate line, switching gate electrode, gate base and gate electrodes; (c)forming an active switching layer on the first insulating layer above the switching and controlling gate electrodes; (d)forming a second metal layer above the active switching and controlling layers; (e)creating a pattern in the second metal layer to form a switching source electrode, a switching output electrode, controlling source electrodes and controlling output electrodes in order to form a switching TFT and a controlling TFT array, the latter comprising sub-TFT's each having a corresponding controlling gate electrode, controlling! active layer, controlling source electrode and controlling output electrode; (f)forming a second insulating layer above the switching source and output electrodes and above the controlling output electrodes and this layer contains source contact holes for exposing parts of the controlling source electrodes; (g)forming a power row on the second insulating layer which combines with the gate and data lines to define the pixel region and which is electrically connected to the controlling source electrodes via the source contact holes; (h)forming a third insulating layer on the second insulating layer in order to cover the power line and this layer contains output contact holes providing access to the controlling output electrodes; (i)forming a first electrode on the third insulating layer within the pixel region, this electrode being in contact with the controlling output electrodes via the output contact holes; and (j)forming a second electrode comprising a transparent material on the organic electroluminescent layer. The second display comprises a first substrate with a gate row, a data row intersecting with the gate row and a power line intersecting with the gate row and electrically connected to sub-TFT's (Thin Film Transistors) in a switching TFT next to the intersection point for the gate and data rows, the sub-TFT's being connected in parallel to the switching TFT via a gate base. The second display also comprises an organic electroluminescent layer provided on top of a second substrate and a connecting pattern between the two substrates which electrically connects the controlling TFT array to the organic electroluminescent diode. The production of the second display comprises the above steps (a)-(i), followed by a step (j) in which a connecting pattern is formed on the third insulating layer, the pattern being located within the pixel region in contact with the controlling output electrodes via the output contact holes and a step (k) in which an organic electroluminescent diode is formed on a second substrate, the diode being electrically connected to the controlling TFT array via the connecting pattern.