OLED Encapsulation via ALD Dielectric and Adhesion Mediator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
OLED structures face limited lifetime due to moisture and oxygen ingress, leading to non-emissive dark spots and poor adhesion between organic and inorganic materials, resulting in device failure and performance degradation.
Innovation Solution
A thin film encapsulation (TFE) structure is developed, incorporating at least one dielectric layer formed by atomic layer deposition (ALD) and two barrier layers, which improves barrier performance while maintaining optical properties and film transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If organic and inorganic materials are used for barrier layers and buffer layers, then moisture resistance and film optical transparency are improved, but surface adhesion at the interface deteriorates
Solution Approach 1:
An intermediate layer is introduced between the organic barrier layer and inorganic buffer layer to serve as a mediator that improves interfacial adhesion. This intermediate layer has properties that are compatible with both materials, preventing peeling and particle generation while maintaining the moisture barrier function of the inorganic layer and optical transparency of the organic layer.
Solution Approach 2:
The encapsulation structure uses a composite material system combining organic barrier layers, inorganic buffer layers, and intermediate adhesion layers. Each material is selected for its specific properties (moisture barrier, optical transparency, adhesion), and their combination creates a synergistic structure that overcomes the limitations of individual materials.
2Manufacturing precision
If buffer layer is used to fill voids or defects in barrier layer, then surface uniformity for deposition is improved, but adhesion between organic and inorganic layers deteriorates
Solution Approach 1:
The intermediate layer serves as a mediator that addresses both surface uniformity and adhesion requirements. It provides a uniform deposition surface for subsequent inorganic layers while simultaneously bonding to both the organic barrier layer below and inorganic buffer layer above, eliminating the adhesion problem caused by using buffer layers alone.
3Ease of manufacture
If poor adhesion at interfaces occurs, then film peeling and particle generation increase, but device reliability deteriorates
Solution Approach 1:
The intermediate adhesion layer prevents film peeling and particle generation by providing strong bonding between organic and inorganic layers. This eliminates the reliability issues associated with poor adhesion while maintaining ease of manufacture through controlled deposition processes.
Solution Approach 2:
The intermediate layer is deposited beforehand to cushion and prevent potential adhesion failures before they occur. This preventive measure ensures that subsequent layers adhere properly, preventing peeling and particle generation that would compromise device reliability.
4Strength
If poor adhesion at interfaces occurs, then film cracking likelihood increases, but moisture or air ingress deteriorates device performance
Solution Approach 1:
The intermediate layer acts as a flexible mediator that accommodates stress between rigid inorganic layers and softer organic layers, preventing film cracking. This maintains film integrity and prevents moisture or air ingress that would deteriorate device performance.
Solution Approach 2:
The intermediate layer changes the mechanical parameters (flexibility, stress distribution) at the interface between organic and inorganic materials. This parameter modification prevents stress concentration and cracking while maintaining the barrier function against moisture and air.
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 TFE structure significantly reduces dark area occurrence and extends the service life of OLED devices by preventing moisture ingress and enhancing adhesion between layers, thus improving the reliability and longevity of OLED displays.
Implementation Method 1
The at least one dielectric layer is deposited by atomic layer deposition (ALD)
Data Source
AI summary
Embodiments described herein generally relate to a method and apparatus for encapsulating an OLED structure, more particularly, to a TFE structure for an OLED structure. The TFE structure includes at least one dielectric layer and at least two barrier layers, and the TFE structure is formed over the OLED structure. The at least one dielectric layer is deposited by atomic layer deposition (ALD). Having the at least one dielectric layer formed by ALD in the TFE structure improves the barrier performance of the TFE structure.