Frit Seal for OLED Substrates Preventing Newton's Rings
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Solution Overview
Problem
Organic light emitting displays face issues with moisture and oxygen infiltration, leading to potential damage and display deterioration, particularly due to non-uniform sealing which can cause Newton's rings when substrates bend, affecting display characteristics.
Innovation Solution
A method involving a frit seal between substrates, where the second electrode directly contacts the second substrate, and the frit is sintered and irradiated to ensure a secure, non-bent interface, preventing moisture and oxygen exposure and eliminating Newton's rings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing structure using metal cap or sealing glass substrate coated with absorbent is used to prevent moisture infiltration, then the organic light emitting diode is protected from moisture, but the sealing may become non-uniform causing Newton's rings and display deterioration
Solution Approach 1:
The patent introduces frit as an intermediary sealing material between the substrate and sealing glass substrate. The frit coating layer acts as a mediator that fills gaps and creates a uniform sealing interface, preventing direct contact between the substrate and sealing glass while still achieving hermetic sealing. This resolves the contradiction by providing both moisture protection and sealing uniformity through the intermediary frit material.
Solution Approach 2:
The patent changes the sealing approach from direct mechanical contact (metal cap or absorbent coating) to a frit-based sealing method where the frit is applied as a coating and then sintered. This parameter change in the sealing mechanism allows for uniform sealing by controlling the frit coating thickness and sintering conditions, thereby preventing Newton's rings while maintaining moisture protection.
2Reliability
If the substrate is sealed using frit coating to achieve perfect sealing, then moisture and oxygen infiltration is prevented, but the fabrication process becomes more complex
Solution Approach 1:
The patent combines multiple functions into the frit coating layer: it serves as both the sealing barrier and the adhesive bonding layer between substrate and sealing glass. By merging these functions into a single material layer, the fabrication process is simplified compared to using separate sealing and bonding layers, while still achieving perfect sealing against moisture and oxygen.
3Manufacturing precision
If the second electrode directly contacts the second substrate without intervening layers, then the substrate interface becomes uniform and Newton's rings are eliminated, but the electrode may be exposed to moisture without protection
Solution Approach 1:
The frit coating layer serves as an intermediary that allows the second electrode to contact the second substrate directly for uniform interface formation, while simultaneously providing the moisture barrier function. The sintered frit creates a hermetic seal around the electrode-substrate interface, protecting the electrode from moisture exposure while maintaining the uniform contact needed to prevent Newton's rings.
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 approach effectively seals the organic light emitting diodes, preventing moisture and oxygen ingress and eliminating Newton's rings, thereby enhancing the display's durability and performance by ensuring a uniform and secure substrate interface.
Implementation Method 1
the frit is sintered and irradiated to ensure a secure, non-bent interface
Implementation Method 2
the frit is sintered and irradiated to ensure a secure, non-bent interface
Data Source
AI summary
Disclosed is an organic light emitting display which avoids an occurrence of Newton's rings in coalesced substrate and sealing substrate. A first substrate includes a pixel region and a non-pixel region. An array of organic light emitting pixels including a first electrode, an organic layer, and a second electrode is formed at the pixel region. A second substrate opposes the first substrate. A frit is disposed between the non-pixel region of the first substrate and the second substrate for interconnecting the first substrate and the second substrate. The second electrode of the array directly contacts a region corresponding to a pixel region of the second substrate.