Method for producing electroluminescent element and vapour-deposition shade

Abstract

An evaporation mask is placed between an evaporation source and a plastic substrate. An evaporation substance from the evaporation source is allowed to selectively pass through one or more openings formed on the evaporation mask corresponding to the pattern of an evaporation layer of an EL element, to form the evaporation layer on the plastic substrate. As the material for the evaporation mask, a material whose thermal expansion coefficient is similar to (for example, within a range of +-30% of) the thermal expansion coefficient of the plastic substrate, for example, a plastic material such as a polyimide, is employed. It is preferable to employ a material having a thermal endurance which is, for example, at least approximately 50 DEG C. higher than the thermal endurance of the plastic substrate. By employing such a material for the evaporation mask, it is possible to ensure that the plastic substrate and the evaporation mask will exhibit the same degree of thermal deformation during evaporation, thereby enabling improvement in the precision of evaporation patterning.

Description

technical field [0001] The present invention relates to a manufacturing method of EL (Electroluminescene) elements formed on a plastic substrate. Background technique [0002] An EL display panel using an organic EL element or the like as a light-emitting element for each pixel is generally known, and a self-luminous flat panel is expected and widely used. [0003] It is generally known that the structure of an organic EL element is to laminate a light-emitting layer between an anode composed of a transparent electrode such as ITO on a glass substrate and a cathode composed of a metal electrode such as aluminum (Al) or magnesium alloy. organic layer. [0004] In the manufacture of such an organic EL element, a vapor deposition method is used to form organic layers and metal electrodes. During vapor deposition, a vapor deposition mask having openings corresponding to predetermined patterns required for each layer is used. For example, due to the poor water resistance of the...

AI Technical Summary

Problems solved by technology

In an organic EL element, since the area sandwiched between the anode and the cathode of the organic layer emits light, when the formation position of the organic layer and the electrode is shifted, the light-emitting area and light-emitting intensity will be unevenly distributed in each pixel

Therefore, in the manufacture of EL display panels, although it is necessary to reliably pattern the laminated layers, in practice, there is a problem that sufficient patterning precision cannot be obtained for the vapor-deposited layer deposited using a nickel mask.

[0008] The present inventor etc. have confirmed that its cause is due to the thermal expansion rate (130*10 -7 / K) is very different from the plastic substrate, so the precision of patterning is reduced

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