Patent ID: 7641737

Claim:
An evaporation source for heating an evaporation material retained in the evaporation source, and emitting a vaporized evaporation material to form an evaporation material layer on a substrate, the evaporation source comprising: a cell retaining the evaporation material therein; a cell cap installed on an upper part of the cell, and having a cell cap aperture for emitting the vaporized evaporation material; an external wall placed outside of the cell with a predetermined distance; heating means disposed between the cell and the external wall, for heating the evaporation material; a cover directly fixed to an upper end of the external wall, the cover having a cover aperture corresponding to the cell cap aperture and disposed in direct contact with an upper surface of the cell cap at its periphery to transfer heat generated from the heating means to the cell cap and the cell cap aperture; a shut-off plate disposed between the cover and the cell cap with its outer circumferential surface attached to an inner circumferential surface of the cover to allow a gap between the shut-off plate and the cover and between shut-off plate and the cell cap; and wherein the cell cap aperture defines an upwardly projecting vapor guide located within the apertures of the cover and the shut-off plate to guide the vapors for projecting upwardly.