Micro LED Electrode Structure for Pad-Safe Element Replacement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In existing micro light-emitting elements, removing a damaged element often damages the corresponding pad on the circuit board, leading to poor bonding when a new element is installed, and this requires additional space for spare pads, affecting circuit layout.
Innovation Solution
The micro light-emitting element design includes an epitaxial structure with an insulating layer and electrode structure extending through an opening, sandwiched by a sacrificial layer, allowing the element to be removed without damaging the pad by breaking at the electrode pillar rather than the pad, eliminating the need for spare pads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If a micro light-emitting element is removed from the circuit board, then the damaged element can be replaced, but the corresponding pad on the circuit board suffers great damage
Solution Approach 1:
The electrode structure is segmented into two parts: an electrode pad portion and an electrode pillar portion. The electrode pad is designed to be separable from the circuit board pad through the sacrificial layer, allowing the light-emitting element to be removed while leaving the circuit board pad intact for future rework
Solution Approach 2:
A sacrificial layer is introduced as an intermediary between the insulating layer and the electrode pad. This sacrificial layer enables controlled separation during removal processes, allowing the electrode pad to detach from the circuit board pad without damaging the circuit board pad, thus preserving bonding quality for future replacements
2Reliability
If spare pads are reserved on the circuit board for replacement, then bonding reliability is ensured, but circuit layout space is reduced
Solution Approach 1:
The electrode pad is designed to serve itself by being detachable from the circuit board pad through the sacrificial layer mechanism. When removal is needed, the electrode pad can be cleanly separated and a new light-emitting element can be bonded to the same circuit board pad, eliminating the need for dedicated spare pads and maximizing circuit board space utilization
Data Source
AI summary
A micro light-emitting element including an epitaxial structure, an insulating layer, an electrode structure and a sacrificial layer is provided. The epitaxial structure includes a top surface and a side surface. The insulating layer is disposed on the top surface and the side surface of the epitaxial structure, and the insulating layer includes an opening. The electrode structure is disposed on the top surface of the epitaxial structure and extends through the opening of the insulating layer to be electrically connected to the epitaxial structure. The sacrificial layer is sandwiched between a surface of the insulating layer and the corresponding electrode structure. A micro light-emitting element display device is further provided.