Micro LED Array Substrate Layout for Laser-Safe Circuit Connections
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Micro LED displays face issues with laser damage at circuit connections on the array substrate, leading to cracks and reduced yield due to the current soldering method.
Innovation Solution
The display device incorporates a spacer layer and a conductive layer that extends orthogonally on the spacer layer, shielding through holes in the conductive layer's projection area to reduce laser damage and increase the distance between the conductive layer and through holes, thereby protecting circuit connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the current soldering method using laser heating is applied to transfer micro LEDs to the array substrate, then mass transfer can be realized, but laser damage occurs at the circuit connections between different layers, resulting in cracks of the circuit connection layer and reduced yield
Solution Approach 1:
The patent introduces a spacer layer as an intermediary component between the conductive layer and the through holes in the insulating layers. This spacer layer serves as a protective mediator that absorbs or deflects laser energy, preventing direct laser damage to the circuit connections during the soldering process while still allowing mass transfer of micro LEDs to proceed
Solution Approach 2:
The patent extends the conductive layer in a specific dimensional configuration where it protrudes beyond the boundaries of the through holes when viewed from the top surface. This dimensional extension creates an overlapping area that provides lateral protection to the circuit connections, adding a spatial dimension to the protection mechanism against laser damage
2Reliability
If the conductive layer is extended to shield through holes, then laser damage is reduced, but the device structure becomes more complex
Solution Approach 1:
The extended conductive layer serves multiple functions simultaneously: it provides electrical connectivity for the micro LEDs, acts as a shield against laser damage to the circuit connections, and defines the structural boundaries for the spacer layer placement. This multi-functionality reduces the need for additional separate protective components, thereby limiting the increase in device complexity
Data Source
AI summary
A display device includes light-emitting elements disposed on an array substrate. The array substrate includes a substrate, switch elements disposed on the substrate, an insulating layer, a connecting layer, a conductive layer and a spacer layer. The insulating layer is disposed on the switching elements and has through holes. The connecting layer is disposed on the insulating layer and is electrically connected to the switching elements through the through holes. The conductive layer is disposed on the connecting layer and includes pads electrically connected to the connecting layer. The spacer layer disposed between the connecting layer and the conductive layer. The conductive layer extends on the spacer layer and is orthographically projected on the substrate to form a first orthographic projection area, where the through holes are located in the first orthographic projection.