Organic electroluminescent display device having a planarizing layer and manufacturing method thereof
The present invention provides an organic EL display device having a planarizing layer, which is prevented from being distorted. The above organic EL display device has a planarizing layer, which retains 5% or less the oligomer used to form this layer.
1. An organic EL display device comprising:
light-emitting elements each having a laminate comprising a lower electrode, an organic layer comprising at least a light-emitting layer, and an upper electrode;
switching elements for controlling light emission and non-light emission of the light-emitting elements; and
a planarizing layer, which is disposed over the switching elements and under the lower electrodes,
wherein the planarizing layer comprises a polymer formed by polymerizing at least one oligomer such that the planarizing layer retains not more than 5% by weight of the at least one oligomer in a non-polymerized form.
2. The organic EL display device according to claim 1 , wherein a surface hardness of the planarizing layer is from 0.3 to 0.6 GPa.
3. The organic EL display device according to claim 1 , wherein a contact angle of the planarizing layer to water is 80° or less.
4. The organic EL display device according to claim 1 , wherein the planarizing layer comprises 150 ppm or less of a metal.
5. The organic EL display device according to claim 1 , wherein the planarizing layer comprises an acrylic resin.
6. A method for manufacturing an organic EL display device, comprising the steps of:
forming a planarizing layer over switching elements disposed on a substrate; and
forming lower electrodes of light-emitting elements each having a laminate comprising a lower electrode, an organic layer comprising at least a light-emitting layer, and an upper electrode,
wherein the step of forming a planarizing layer comprises disposing at least one oligomer having a molecular weight of 500 to 5,000 and polymerizing the at least one oligomer such that the planarizing layer retains not more than 5% of the at least one oligomer in a non-polymerized form.
7. The method for manufacturing an organic EL display device according to claim 6 , wherein the polymerization is performed by heat and/or light.
8. The method for manufacturing an organic EL display device according to claim 6 , wherein a temperature during the polymerization is increased at a rate of 2 to 20° C./minute.