Patent ID: 7837528

Claim:
A method of manufacturing an organic electroluminescent (EL) device, the method comprising: forming first electrodes on a substrate; disposing an evaporation mask to form an organic film over the substrate, the evaporation mask drawn taut by application of tension and having at least one mask unit, the mask unit comprising a plurality of main apertures and a plurality of first dummy apertures formed adjacent to outermost ones of the main apertures in a direction in which tension is applied to the evaporation mask; forming the organic film comprising an effective luminescent area to cover at least the first electrodes by evaporating an organic material containing an organic luminescent material through the main apertures, and forming a first dummy pattern area outside the effective luminescent area through the first dummy apertures; forming second electrodes on the organic film so that the effective luminescent area is formed at an area where the first and second electrodes overlap; and sealing the resulting structure, wherein at least two organic EL devices are manufactured in a single process, and the evaporation mask comprises at least two mask units, through each of which the organic film of a single organic EL device can be deposited, and a plurality of second dummy apertures outside and adjacent to outermost ones of the mask units in the direction in which tension is applied to the evaporation mask.