LED Conductive Area Formation via Polymer Mask Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional display manufacturing processes for micro and mini light-emitting diode displays are complex and costly, with multiple steps required to produce a single display, necessitating a reduction in process steps to enhance efficiency and reduce costs.
Innovation Solution
A method for forming a conductive area at the top surface of a light-emitting diode involves preparing a substrate with a conductive pad, bonding the light-emitting diode, forming a polymer layer to cover the substrate and diode, and etching the polymer layer to expose the second type semiconductor layer without using a mask layer, thereby omitting the need for a mask layer forming process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a traditional multi-step manufacturing process is used for micro and mini light-emitting diode displays, then the manufacturing precision and reliability are maintained, but the device complexity and manufacturing cost increase, and productivity decreases
Solution Approach 1:
The patent combines multiple manufacturing steps into a single integrated process. Specifically, the method merges the bonding process and the exposure process into one operation by forming the polymer layer during bonding, which then serves as both the bonding medium and the exposure mask, eliminating the need for separate mask layer formation and reducing the total number of process steps
Solution Approach 2:
The polymer layer performs multiple functions simultaneously: it acts as a bonding agent to attach the light-emitting diode to the substrate, serves as a protective covering during processing, and functions as an exposure mask to define the conductive area pattern. This multi-functionality reduces the number of separate components and process steps required
2Ease of manufacture
If a mask layer is formed and processed separately, then the manufacturing precision is maintained, but the device complexity and manufacturing cost increase
Solution Approach 1:
The method merges mask formation with the bonding process by forming the polymer layer in situ during bonding. This integration ensures that the mask pattern is automatically aligned with the bonding area, maintaining precision while simplifying the manufacturing process by eliminating separate mask formation steps
Solution Approach 2:
The polymer layer forms self-aligned patterns through the bonding process itself. The bonding conditions and geometry automatically define the mask pattern boundaries, eliminating the need for separate photolithography alignment steps and reducing manufacturing complexity while maintaining precision
3Manufacturing precision
If the polymer layer is etched to expose the second type semiconductor layer, then the conductive area is formed correctly, but the first type semiconductor layer and active layer must remain protected
Solution Approach 1:
The polymer layer is designed with non-uniform thickness: thicker regions over the first type semiconductor layer and active layer provide protection during etching, while thinner regions over the second type semiconductor layer allow exposure. This local variation in thickness creates different etching rates and protection levels in different areas, achieving precise selective exposure without complex masking
Solution Approach 2:
The method uses polymer layer thickness as a control parameter to determine etching behavior. By varying the thickness of the polymer layer in different regions, the etching process selectively exposes the second type semiconductor layer while protecting the first type semiconductor layer and active layer, achieving precise pattern definition through parameter control rather than complex masking
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 method reduces manufacturing costs and enhances efficiency by eliminating the need for a mask layer, allowing direct exposure of the second type semiconductor layer while maintaining electrical isolation and improving light-emitting efficiency.
Implementation Method 1
etching the polymer layer till the second type semiconductor layer to expose the top surface of the light-emitting diode from the polymer layer, in which the first type semiconductor layer and the active layer are free from exposing by the polymer layer
Data Source
AI summary
A method of forming a conductive area at a top surface of a light-emitting diode includes: preparing a substrate having a top surface with a conductive pad thereon; bonding a light-emitting diode having first and second type semiconductor layers and an active layer to the conductive pad; forming a polymer layer on the substrate such that a difference between a distance from a first surface of the polymer layer to the top surface of the substrate and a distance from a second surface of the polymer layer to a top surface of the light-emitting diode is greater than a distance from an interface between a second type semiconductor layer and an active layer to the top surface of the substrate; and etching the polymer layer till the second type semiconductor layer to expose the top surface of the light-emitting diode from the polymer layer.