Composite film packaging method of top-emitting OLED

Abstract

The invention provides a composite film packaging method for a top-emitting OLED. The method comprises the following steps: carrying out vacuum evaporation of a pre-packaging layer on the surface of acathode of a top-emitting OLED to obtain a pre-packaging device, wherein the pre-packaging layer comprises metal oxide layers and metal layers which are alternately stacked and arranged; and depositing a thin film packaging layer on the surface of the pre-packaging layer of the pre-packaging device to obtain a composite thin film packaging device, wherein the thin film packaging layer comprises at least one of a silicon oxide thin film and a silicon nitride thin film. According to the invention, the metal oxide layers and the metal layers which are alternately stacked and arranged through vacuum evaporation are used as the pre-packaging layer, so that air can be isolated and water vapor is prevented from permeating into the device to influence the performance; by depositing a silicon oxide film and / or a silicon nitride film as a film packaging layer, the permeability of oxygen and water vapor is relieved; and experiment results show that the water vapor transmission rate of the composite film is 3.85*10<-5> g / m<2>.day under the condition of 60 DEG C / 90% RH.

Description

technical field [0001] The invention belongs to the technical field of organic electroluminescence, and in particular relates to a composite film encapsulation method of a top-emitting OLED. Background technique [0002] An organic electroluminescent display device is a device that uses an electric current to drive an organic semiconductor thin film to emit light, referred to as OLED. According to the direction of light emission, OLED can be divided into two structures: bottom light emission (bottom emission) and top light emission (top emission). The transparent anode of the bottom-emitting OLED device is located on the transparent substrate. On the transparent anode is a multi-layer organic film layer. On the organic film layer is a total reflection metal or alloy cathode. Light can only be emitted from the substrate through the anode. However, in an active matrix organic electroluminescent display, a pixel driving circuit must be fabricated under the device. If a bottom-...

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Problems solved by technology

What's more serious is that the organic material itself will have an irreversible chemical reaction with water vapor and oxygen, destroying the structure of organic molecules and polymers, reducing its luminous efficiency and affecting the life of the device

[0004] In the existing packaging technology, the rigid cover plate used is usually glass or metal. If a metal cover plate is used for packaging, there is a possibility of short circuit caused by the contact between the cover plate and the device electrode, which will affect the yield of the device. At the same time, in The desiccant inside the cover will absorb part of the light emitted by the device, affecting the light extraction rate and reducing the efficiency of the device; there are also several layers of transparent organic thin films deposited on the cathode of the device as a buffer layer or several layers of MgF 2 , ZnS or MgF 2 / ZnS film is used as a pre-encapsulation layer, and then chemical vapor deposition is used to prepare silicon oxide and silicon nitride encapsulation films to form a buffer layer or a composite thin-film encapsulation structure (such as patent CN102569678A) in which a buffer layer or a pre-encapsulation layer and an encapsulation layer film are combined, although its encapsulation To a certain extent, the technology can alleviate the impact of the penetration of oxygen and water vapor in the air during the transfer of the cathode of the top-emitting OLED device from the vacuum evaporation equipment to the PECVD equipment. The ability of its packaging technology to alleviate the penetration of oxygen and water vapor in the air can no longer meet the requirements

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