Textured LED Substrate Trenches for Light Extraction
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Solution Overview
Problem
Conventional methods for directing light from LEDs to achieve uniform light distribution are costly and complex, and do not effectively improve light-extraction efficiency.
Innovation Solution
A textured substrate with trenches is used, where the LED active layer has portions parallel to the sidewalls and bottoms of the trenches, allowing light to be emitted in multiple directions, increasing the light output area and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If patterned package substrates are bonded to LED chips to redirect light, then light direction control is improved, but manufacturing cost and process complexity increase
Solution Approach 1:
The patent combines the light redirection function with the substrate itself by creating textured structures (trenches, grooves, or bumps) directly on the substrate surface. This merges the substrate's structural role with the light direction control function, eliminating the need for separate patterned package substrates and reducing manufacturing complexity.
Solution Approach 2:
The patent introduces surface texture dimensions (vertical trenches, grooves, or bumps) on the substrate to achieve light direction control. By adding this dimensional feature to the substrate surface, light scattering and redirection are achieved without requiring complex planar patterning processes.
2Illumination intensity
If patterned package substrates are used to scatter light for uniform distribution, then light uniformity is improved, but manufacturing cost increases
Solution Approach 1:
The light scattering function is merged into the substrate structure through textured surfaces. The trenches, grooves, or bumps on the substrate surface inherently scatter light to achieve uniform distribution, eliminating the need for expensive patterned package substrates.
Solution Approach 2:
The substrate structure itself provides the light scattering function through its textured surface features. The substrate serves dual purposes: as the structural base and as the light redistribution element, making the system self-sufficient and reducing overall manufacturing cost.
3Ease of manufacture
If conventional flat LED structures are used, then manufacturing is simpler, but light-extraction efficiency is poor
Solution Approach 1:
The patent adds vertical dimensionality to the LED structure by creating trenches, grooves, or bumps on the substrate surface. This dimensional change increases the light extraction path length and surface area, significantly improving light-extraction efficiency while maintaining manufacturing simplicity through direct substrate patterning.
Solution Approach 2:
The textured substrate features (curved sidewalls of trenches, rounded bumps, or grooved profiles) create multiple light reflection angles and paths. These curved surfaces enhance light extraction by preventing direct back-reflection and distributing light more effectively, improving efficiency without complex manufacturing.
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 enhances light uniformity and output while reducing manufacturing complexity and cost by scattering light more effectively, making it suitable for illumination applications without the need for patterned package substrates.
Implementation Method 1
the light being scattered to achieve a more uniform light distribution
Data Source
AI summary
A device includes a textured substrate having a trench extending from a top surface of the textured substrate into the textured substrate, wherein the trench comprises a sidewall and a bottom. A light-emitting device (LED) includes an active layer over the textured substrate. The active layer has a first portion parallel to the sidewall of the trench and a second portion parallel to the bottom of the trench.