Patent ID: 6626721
Filing Date: 2003-09-30
Classification: H01L

Abstract:
A method of making a passive matrix pixelated organic electroluminescent (EL) device having a thin cathode, comprising the steps ofa) providing a substrate having a plurality of spaced anodes formed thereon and a plurality of spaced cathode connectors extending inwardly from an edge of the substrate for providing an electrical connection so that a drive voltage can be applied between a selected anode and a selected thin cathode to cause light emission from a pixel of the device formed by the selected anode and the selected cathode; b) forming a plurality of spaced electrically insulative base layers over the anodes and the substrate which extend in a direction perpendicular to the anodes and over a portion of each of the spaced cathode connectors and forming an opening or a cut-out in the base layers to extend to the cathode connectors in the portion; c) forming a conductive cathode bus metal layer over a portion of each of the base layers, the bus metal layer extending at least into the opening or cut-out to provide an electrical contact to each of the spaced cathode connectors; d) forming an electrically insulative organic cathode separation shadowing structure over each of the base layers and forming at least one organic cathode bus shadowing structure over a portion of the cathode bus metal layer; e) providing a mask defining a deposition zone over the substrate for depositing an organic EL medium layer and a conductive cathode over the organic EL medium layer; f) first depositing the organic EL medium layer by vapor deposition of organic EL materials directed towards the substrate into the deposition zone and using a direction of vapor deposition of the organic EL materials with respect to the shadowing structures formed in step d) to cause formation of the organic EL medium layer to terminate at positions spaced from a base of each of the shadowing structures; and g) second depositing a conductive thin cathode by a vapor deposition of conductive cathode materials directed towards the organic EL medium layer into the deposition zone and using a direction of vapor deposition of the conductive materials with respect to the shadowing structures formed in step d) to cause formation of a plurality of spaced thin cathodes, each of such spaced cathodes being in electrical contact with a corresponding cathode bus metal layer in the positions where the organic EL medium layer is spaced from the base of the at least one cathode bus shadowing structure.