Evaporation source for evaporating an organic
View Patent ↗The present invention relates to an evaporation source for evaporating an organic electroluminescent layer. In particular, the present invention relates to the evaporation source preventing an aperture, through which a vaporized evaporation material is emitted, from being clogged by restricting heat transfer to outward. The evaporation source according to the present invention includes a cell retaining an evaporation material therein; a cell cap installed on the upper part of the cell and having a cell cap aperture for emitting a vaporized evaporation material; an external wall placed in the outside of the cell to support a heating means set up at the outside of the cell; a cover placed above the cell cap, fixed to the upper end of the external wall, and having a cover aperture corresponding to the cell cap aperture; and a shut-off plate placed between the cover and the cell cap and having a shut-off plate aperture corresponding to the cell cap aperture and the cover aperture in the center of the shut-off plate.
1. 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.
2. The evaporation source of claim 1 , a size of the cover aperture is substantially the same as a size of the cell cap aperture.
3. The evaporation source of claim 2 , wherein a thickness of the cover is decreased in a direction of the cover aperture.
4. The evaporation source of claim 1 , further comprising a shut-off layer formed on an upper surface of the cover, and having a shut-off layer aperture corresponding to the cover aperture.
5. The evaporation source of claim 4 , wherein a size of the shut-off layer aperture is larger than a size of the cover aperture.
6. The evaporation source of claim 4 , wherein a size of the shut-off layer aperture is substantially the same as a size of the cover aperture.
7. The evaporation source of claim 6 , wherein a thickness of the shut-off layer is decreased in a direction of the shut-off layer aperture.
8. The evaporation source of claim 6 , wherein the shut-off layer is made of low conductivity material.
9. The evaporation source of claim 4 , wherein the shut-off layer is made of ceramic material or metal material, wherein the ceramic material comprises Al 2 O 3 , TiO 2 , SiC or ZrO 2 , and the metal material comprises Mn or Ti.