Display Electrode Layout to Prevent Peripheral Peeling Defects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The yield of display devices is decreased due to peeling defects of the upper electrode occurring during the manufacturing process, as the mask directly contacts the lower pattern in the peripheral area, causing disconnection and defects.
Innovation Solution
A display device design where the upper electrode contacts only the first lower pattern in the first area and overlaps the second lower pattern in the second area, with the pixel defining layer entirely covering the second lower pattern, preventing direct contact and potential peeling defects during the formation of the upper electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the mask directly contacts the lower pattern in the peripheral area during upper electrode formation, then the upper electrode can be formed, but peeling defects occur and yield decreases
Solution Approach 1:
The patent introduces a pixel defining layer as an intermediary between the upper electrode and the lower pattern in the peripheral area. This intermediate layer prevents direct contact between the mask and the lower pattern during upper electrode formation, eliminating the peeling defect while still allowing the upper electrode to be properly formed through the opening in the pixel defining layer.
2Reliability
If the upper electrode contacts the lower pattern in the peripheral area, then electrical connection is achieved, but peeling defects occur during manufacturing
Solution Approach 1:
The patent segments the functional areas by creating a pixel defining layer with a specific opening configuration. The opening is positioned to allow upper electrode contact with the lower pattern only in the display area, while the peripheral area remains covered by the pixel defining layer. This segmentation enables electrical connection where needed while preventing manufacturing defects where not needed.
Solution Approach 2:
The pixel defining layer is designed with spatially varying properties: it has an opening in the display area to permit electrical connection between the upper electrode and lower pattern, while remaining intact in the peripheral area to prevent mask contact and peeling defects. This local differentiation of the pixel defining layer's structure optimizes both electrical connection and manufacturing reliability in different regions.
3Productivity
If the mask contacts the lower pattern during upper electrode formation, then the process can proceed, but disconnection and defects occur
Solution Approach 1:
The pixel defining layer serves as a protective intermediary that allows the upper electrode formation process to proceed continuously without mask contact issues. By placing this intermediate layer, the process maintains productivity while eliminating the peeling and disconnection defects that would otherwise occur.
Data Source
AI summary
A display device comprises a first lower pattern disposed in a first area and disposed in a same layer as an emission lower electrode, a second lower pattern disposed in a second area adjacent to the first area and disposed in a same layer as the first lower pattern, and an upper electrode disposed on the second lower pattern, contacting the first lower pattern in the first area, and overlapping the second lower pattern in the second area not to contact the second lower pattern.