Micro LED Display Panel Edge Pad Layout With Peripheral Dummy Pattern
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Solution Overview
Problem
The manufacturing process of micro LED display panels faces challenges in achieving high yield due to incomplete definition of pad patterns near the substrate edge, resulting from photoresist loss during patterning, which affects the bonding of micro LED dies and reduces production yield.
Innovation Solution
Incorporating a dummy pattern in the peripheral area between the edge pads and the substrate edge helps to prevent photoresist loss and ensures correct definition of edge pads, thereby improving the production yield of micro LED display panels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of metal conductive layers and planarization layers is increased to improve pixel resolution, then the optical performance is improved, but the height of pads increases and photoresist loss during patterning occurs, reducing manufacturing yield
Solution Approach 1:
The patent applies preliminary action by extending the planarization layers beyond the substrate edge before the patterning process. This pre-positioning of the planarization layers ensures that when photoresist is applied and patterned for edge pads, the photoresist has adequate support structure and cannot be lost or displaced during the patterning process, thereby preventing definition failures of edge pads
Solution Approach 2:
The patent uses the planarization layers as an intermediary structure between the substrate edge and the edge pads. By extending this intermediary layer beyond the substrate edge, it provides a stable platform that prevents photoresist loss during patterning, thus mediating the conflict between achieving high pixel resolution (requiring multiple layers) and maintaining manufacturing yield (requiring complete pad definition)
2Manufacturing precision
If photoresist patterns are used for patterning pads near the substrate edge, then the pad patterns can be defined, but photoresist loss occurs during the patterning process, resulting in incomplete definition of edge pads
Solution Approach 1:
The planarization layers are extended beyond the substrate edge in advance, creating a preliminary structural foundation. This ensures that when photoresist is applied for edge pad patterning, it has adequate support and cannot be lost during the patterning process, thereby preventing incomplete definition of edge pads
Solution Approach 2:
The extended planarization layers serve as a cushioning structure that prevents photoresist loss. By providing this protective structure beforehand, the patent ensures that photoresist patterns near the substrate edge remain stable during patterning, preventing the harmful effect of photoresist material loss
Data Source
AI summary
A display panel has a plurality of pixel areas and a peripheral area surrounding the pixel areas, and includes a substrate, at least two planarization layers, a plurality of pads, a first dummy pattern, and a plurality of light-emitting devices. The substrate has a first substrate edge extending in a first direction. The at least two planarization layers are disposed on the substrate. The pads are disposed on the at least two planarization layers, and are located in the pixel areas. The pads include at least one first edge pad closest to the first substrate edge. The first dummy pattern is disposed on the at least two planarization layers, and extends in the peripheral area between the at least one first edge pad and the first substrate edge. The light-emitting devices are electrically connected to the pads.