OLED Sealing with Dual Adhesive Layers for Low-Temperature Bonding
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Solution Overview
Problem
Organic light emitting display apparatuses deteriorate due to permeation of external oxygen and water vapors, and existing sealing processes using inorganic sealants require high-temperature bonding and long laser irradiation, which is not suitable for large-area substrates and can damage the devices.
Innovation Solution
The use of a low-temperature bonding process with an organic material-based first adhesive layer surrounding the display area and a second adhesive layer, including solder material, to prevent oxygen and water vapor permeation without the need for laser irradiation, while maintaining device rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frit sealing is used to prevent oxygen and water vapor permeation, then sealing effectiveness is improved, but high-temperature bonding is required which damages the organic light emitting display apparatus
Solution Approach 1:
The patent changes the bonding temperature parameter from high-temperature (frit process) to low-temperature (organic adhesive process) by substituting the sealing material and process, thereby preventing damage to the organic light emitting display apparatus while maintaining sealing effectiveness
Solution Approach 2:
The patent uses organic adhesive materials that can be applied and cured at low temperatures rather than expensive frit materials requiring high-temperature processing, making the process suitable for heat-sensitive OLED structures
2Reliability
If frit sealing process is used, then sealing is achieved, but long laser irradiation duration is required which is not suitable for large-area substrates
Solution Approach 1:
The patent replaces the laser-based frit sealing process with a chemical adhesive bonding process that does not require laser irradiation, thereby eliminating the time constraint for large-area substrate processing and enabling uniform sealing across large areas
Solution Approach 2:
The organic adhesive layer is applied in advance to the substrate before the sealing process, allowing the bonding to occur at low temperature without requiring prolonged laser irradiation during the sealing process itself
3Reliability
If frit sealing is used, then oxygen and water vapor permeation is prevented, but rigidity of manufactured devices decreases
Solution Approach 1:
The patent uses a composite sealing structure combining organic adhesive material with additional support layers or结构设计 to maintain both flexibility for low-temperature bonding and sufficient rigidity for device performance, avoiding the rigidity loss associated with frit sealing
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
This solution effectively prevents oxygen and water vapor permeation, reduces manufacturing time and costs, and avoids damage to the OLEDs, while allowing for high rigidity and efficient production of large-area displays.
Implementation Method 1
When a voltage is applied to the pixel electrode and the opposite electrode, holes injected from the pixel electrode are combined with electrons injected from the opposite electrode in the organic light emitting layer, thereby forming excitons. The formed excitons are transitioned to a ground state, thereby generating energy. The organic light emitting layer emits light in response to the generated energy
Implementation Method 2
a first adhesive layer surrounding the display area, which bond the substrate to the seal, and including an organic material, and a second adhesive layer insulated from the pad area by the insulating layer, disposed outside the first adhesive layer, which bond the substrate to the seal
Data Source
AI summary
An organic light emitting display apparatus is disclosed. The organic light emitting display apparatus includes: a substrate, a seal facing the substrate, bonded to the substrate, a display area disposed on the substrate configured to produce an image, a pad area disposed on the substrate, present on at least one side of the display area, an insulating layer directly extending from the display area, formed on the pad area, a first adhesive layer surrounding the display area, which bonds the substrate to the seal, and comprising an organic material, and a second adhesive layer insulated from the pad area by the insulating layer, disposed outside the first adhesive layer, which bonds the substrate to the seal.