Display Pad Encapsulation Layout Without Mask Etching Damage
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Solution Overview
Problem
The existing manufacturing processes for display devices require the use of mask structures to deposit encapsulation layers without overlapping pad electrodes, leading to increased process costs and potential damage to the pad electrodes and protective insulating layers during etching, which can result in contact failures and reduced reliability.
Innovation Solution
A method involving the formation of a conductive layer with specific etching rates for dry and wet etching processes, allowing for the deposition of inorganic encapsulation layers over the entire display and pad areas without masks, and selectively removing overlapping parts using dry and wet etching processes to prevent damage to the pad electrodes and protective insulating layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mask structure is used to deposit the encapsulation layer avoiding the pad electrode, then the encapsulation layer does not overlap the pad electrode, but the process cost increases
Solution Approach 1:
A conductive layer is formed in advance in the pad area before depositing the encapsulation layer. This preliminary conductive layer serves as a protective barrier during encapsulation deposition, eliminating the need for mask structures while preventing encapsulation layer overlap with the pad electrode.
Solution Approach 2:
The conductive layer acts as an intermediary protective layer between the pad electrode and the encapsulation layer. It prevents direct contact and overlap between these two layers, serving the same protective function as a mask structure would, but without the complexity and cost of mask fabrication and alignment.
2Reliability
If a mask structure is used to deposit the encapsulation layer, then the encapsulation layer does not overlap the pad electrode, but the pad electrode may be damaged
Solution Approach 1:
The conductive layer is formed in advance in the pad area before encapsulation deposition. This preliminary structure protects the pad electrode from potential damage during the encapsulation process by serving as a physical barrier and stress distribution layer.
Solution Approach 2:
The conductive layer serves as a protective intermediary between the pad electrode and the encapsulation layer deposition process. It absorbs or distributes mechanical stresses and prevents direct contact that could cause damage to the pad electrode, eliminating the need for mask structures that pose damage risks.
3Reliability
If the conductive layer is disposed between the encapsulation layer and pad electrode, then the pad electrode is protected from damage, but the device structure becomes more complex
Solution Approach 1:
The conductive layer performs multiple functions simultaneously: it serves as an electrical connection layer, a protective barrier during encapsulation deposition, and a stress distribution layer. By combining multiple functions into a single layer, the overall device complexity is minimized while achieving pad electrode protection.
Solution Approach 2:
The protective function is merged with the existing conductive layer that is already part of the device structure. Instead of adding a separate protective layer or using a mask structure, the conductive layer is positioned and configured to serve both electrical and protective roles, reducing overall structural complexity.
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 reduces the number of mask structures needed, lowers manufacturing costs, and enhances the reliability of the display device by preventing damage to the pad electrodes and protective insulating layers, ensuring reliable electrical connections.
Implementation Method 1
removing a part of the inorganic encapsulation layer overlapping at least a part of the pad electrode through a first etching process, and removing a part of the conductive layer overlapping at least a part of the pad electrode through a second etching process
Implementation Method 2
forming an inorganic encapsulation layer on the protective insulating layer
Data Source
AI summary
A display device according to an embodiment of the present invention may include a substrate including a display area and a pad area located on one side of the display area, a pad electrode disposed in the pad area on the substrate, a protective insulating layer disposed on the substrate and the pad electrode to expose at least a part of a top surface of the pad electrode, an inorganic encapsulation layer disposed on the protective insulating layer, and a conductive layer disposed in the pad area between an end of the inorganic encapsulation layer adjacent to the pad electrode and the protective insulating layer.