Adjacent LED Wire Chips With Segmented Growth for Uniform Emission
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Solution Overview
Problem
Existing epitaxial processes for producing GaN-based LED wires suffer from nonuniformities and defects due to edge effects and discontinuities in wire growth, leading to issues like parasitic growth and nonuniform light emission across the wafer.
Innovation Solution
A process involving the growth of LED wires over a substrate with selective removal of wires in certain regions to define individual chips, using a transparent conductive layer to connect adjacent chips, thereby avoiding nonuniformities and defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If epitaxial processes are used to produce GaN-based LED wires, then light emission is achieved, but nonuniformities and defects appear due to edge effects and discontinuities in wire growth
Solution Approach 1:
The patent divides the continuous wire growth process into discrete segments by using a mask with individual growth zones. Each zone is isolated from others, allowing uniform growth conditions in each segment while avoiding edge effects at boundaries. This segmentation enables parallel growth of multiple wires without mutual interference.
Solution Approach 2:
The invention applies local quality by creating distinct growth conditions in different regions of the substrate. The mask defines specific zones where wires grow with optimal conditions, while other regions remain free from edge effects. This localized approach ensures high uniformity in wire growth within each defined zone.
2Productivity
If continuous wire growth is performed over large areas, then productivity increases, but parasitic growth and defects increase due to edge effects
Solution Approach 1:
The substrate surface is segmented into multiple isolated growth zones using a mask pattern. This allows large-area wire growth while preventing parasitic growth between zones, as each zone is independently defined and separated by mask material that suppresses unwanted nucleation.
Solution Approach 2:
The mask acts as an intermediary element that enables large-area growth while blocking parasitic growth. It mediates between the desire for high productivity (large growth area) and the need to eliminate harmful effects (parasitic growth), by providing physical isolation between growth zones.
3Area of moving object
If wires are grown in dense arrays, then emitting area increases, but current density in the active zone increases leading to overheating
Solution Approach 1:
The dense wire array is segmented into individually addressable units through the mask-defined growth zones. This allows the total emitting area to be large while maintaining low current density in each active zone, as current can be distributed across multiple independent wire groups rather than concentrated in a single continuous structure.
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 approach ensures uniform wire growth and reduces parasitic growth, achieving high uniformity and efficiency in light emission across the wafer, allowing for better control and logistics in chip production.
Implementation Method 1
producing, on a substrate, a plurality of individual zones for growing wires
Implementation Method 2
depositing a transparent conductive layer on each array of wires so as to electrically connect the wires
Data Source
AI summary
A process for producing at least two adjacent regions, each comprising an array of light-emitting wires connected together in a given region by a transparent conductive layer, comprises: producing, on a substrate, a plurality of individual zones for growing wires extending over an area greater than the cumulative area of the two chips; growing wires in the individual growth zones; removing wires from at least one zone forming an initial free area to define the arrays of wires, the initial free area comprising individual growth zones level with the removed wires; and depositing a transparent conductive layer on each array of wires to electrically connect the wires of a given array of wires, each conductive layer being separated from the conductive layer of the neighbouring region by a free area. A device obtained using the process of the invention is also provided.