Multi-Layer Connection Pad Cladding for OLED Bonding Reliability
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Solution Overview
Problem
The bonding process in organic light-emitting display devices often results in defects, reducing the reliability of the display device due to issues like exposure of conductive layers and subsequent galvanic reduction of metal ions, which can lead to contamination and shorts.
Innovation Solution
A display device structure with a connection pad having a multi-layered conductive configuration, where a cladding layer covers the intermediate conductive layers to prevent exposure and includes an organic material susceptible to heat and moisture, which is removed before bonding to enhance reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional bonding process is used to attach the driving chip to the substrate, then the display device can be assembled, but bonding defects occur that reduce reliability
Solution Approach 1:
The patent applies preliminary action by forming a protective cladding layer on the intermediate conductive layer before the bonding process. This cladding layer prevents metal ion exposure and galvanic reduction during bonding, eliminating the need for complex post-bonding defect repair processes and improving bonding reliability without significantly increasing manufacturing complexity
Solution Approach 2:
The patent introduces a cladding layer as an intermediary between the intermediate conductive layer and the external environment during bonding. This cladding layer acts as a protective mediator that prevents harmful galvanic reduction reactions while allowing the bonding process to proceed, thus improving reliability without adding significant process complexity
2Productivity
If the intermediate conductive layer is exposed during bonding, then the bonding process can proceed, but galvanic reduction of metal ions occurs causing contamination and shorts
Solution Approach 1:
The patent converts the potentially harmful exposure of the intermediate conductive layer into a beneficial protected state by applying a cladding layer. This cladding layer transforms the vulnerable exposed surface into a protected interface that prevents galvanic reduction while maintaining bonding efficiency, thus eliminating metal ion contamination without reducing productivity
Solution Approach 2:
The cladding layer serves as an intermediary protective barrier between the intermediate conductive layer and the bonding environment. It prevents direct contact between metal ions and external elements that would cause galvanic reduction, thereby eliminating contamination while allowing the bonding process to proceed efficiently
3Reliability
If a multi-layered connection pad structure is implemented to prevent exposure, then reliability improves, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the connection pad into distinct functional layers: a lower conductive layer, an intermediate conductive layer, and a protective cladding layer. This segmentation allows each layer to perform its specific function while maintaining overall reliability without excessive complexity, as the cladding layer is a simple protective addition rather than a complex multi-component structure
Solution Approach 2:
The patent applies local quality by providing the cladding layer specifically on the intermediate conductive layer where protection is most needed during bonding. This localized protection approach improves reliability at the critical bonding interface without adding complexity to the entire connection pad structure, as the protective layer is applied only where necessary rather than uniformly across all components
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 solution effectively prevents bonding failures and improves the reliability of the display device by minimizing exposure of conductive layers and reducing the formation of metal ions, thus enhancing the stability and performance of the organic light-emitting display.
Implementation Method 1
exposure of conductive layers and subsequent galvanic reduction of metal ions
Data Source
AI summary
A display device includes a light-emitting element disposed in a display area. A connection pad is disposed in a bonding area of a non-display area. The connection pad includes a lower conductive layer, an intermediate conductive layer disposed on the lower conductive layer and an upper conductive layer disposed on the intermediate conductive layer. A lower surface of the upper conductive layer directly contacts an upper surface of the intermediate conductive layer without an intermediate member disposed therebetween.