OLED Encapsulation Metal Layer for Moisture Blocking
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Solution Overview
Problem
Organic light emitting diode (OLED) devices are prone to degradation due to moisture and oxygen exposure, which affects their lifespan, as the reactive metal cathode materials can react with these elements, leading to chemical reactions that invalidate the device, and existing thin film encapsulation methods have inadequate blocking abilities.
Innovation Solution
A chemical plating method is used to form a metal layer, specifically a two- or three-layer structure of nickel and silver, on top of an inorganic or organic encapsulation layer to enhance the blocking of moisture and oxygen, thereby improving the encapsulation effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a thin film encapsulation layer composed of inorganic thin film and organic thin film is used, then the device structure is simple and manufacturing is easy, but the blocking ability against moisture and oxygen permeation is insufficient
Solution Approach 1:
The patent applies composite materials by combining inorganic thin film layers (such as aluminum oxide, silicon oxide, or silicon nitride) with organic thin film layers (such as polyethylene terephthalate or polyimide) to create a multi-layer encapsulation structure. This composite approach leverages the advantages of both material types: inorganic layers provide excellent barrier properties against moisture and oxygen permeation, while organic layers provide flexibility and ease of manufacturing. The synergistic combination resolves the contradiction by achieving both high blocking ability and manufacturing simplicity.
2Device complexity
If the cathode is exposed to moisture and oxygen, then the device structure is simple without additional encapsulation layers, but chemical reactions occur between the reactive metal cathode materials and moisture/oxygen leading to device invalidation
Solution Approach 1:
The patent creates an inert environment by forming encapsulation layers that effectively isolate the cathode from moisture and oxygen in the atmosphere. The inorganic thin film layers (aluminum oxide, silicon oxide, silicon nitride) and organic thin film layers work together to establish a protective barrier that maintains an inert atmosphere around the reactive metal cathode materials, preventing chemical reactions and extending device lifespan while adding minimal structural complexity.
3Reliability
If a substrate encapsulation type with adhesive film is used, then the encapsulation effect is achieved by forming a closed space, but the adhesive film curing process adds manufacturing complexity and potential reliability issues
Solution Approach 1:
The patent extracts and eliminates the adhesive film component from the encapsulation structure. Instead of using substrate encapsulation with adhesive films that require curing processes, the invention employs a thin film encapsulation approach where inorganic and organic thin film layers are directly deposited to form the encapsulation barrier. This extraction of the adhesive film simplifies the manufacturing process by removing the curing step and associated complexity while maintaining reliable encapsulation effects through the deposited thin film layers.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method significantly enhances the blocking ability of moisture and oxygen, extending the lifespan of OLED devices by preventing chemical reactions at the cathode and improving the encapsulation efficiency, with the metal layer effectively covering the upper and side surfaces of the first encapsulation layer.
Implementation Method 1
The second encapsulation layer is formed through a chemical plating method. The chemical plating comprises at least one selected from the group consisting of chemical silver-plating, chemical copper-plating, chemical nickel-plating and chemical gold-plating.
Data Source
AI summary
An encapsulation method and encapsulation structure of an organic light emitting diode (OLED) are provided. The method includes: preparing an OLED substrate, the OLED substrate comprises a base substrate and at least one OLED device formed on the base substrate; forming a first encapsulation layer at a side of the OLED substrate formed with the OLED device to cover the OLED device; and forming a second encapsulation layer on the first encapsulation layer, the second encapsulation layer is a metal layer.