LED Encapsulation with Beveled Recesses for High Lumen Density
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Solution Overview
Problem
Current LED devices face challenges in achieving high lumen output density while minimizing device size, with existing solutions often resulting in increased package size and inefficient light emission due to internal reflections and manufacturing imperfections.
Innovation Solution
The development of substrate-based LED devices with a light-transmissive encapsulation material and beveled recesses on the top surface, along with electrical vias under the LEDs, enhances light transmission and reduces unwanted reflections, achieving a higher lumen output density of at least 200 lumens per square millimeter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional LED packaging is used, then device structure is simple, but lumen output density is low due to internal reflections and inefficient light emission
Solution Approach 1:
The encapsulation material is segmented into multiple functional regions including a flat top surface for direct light extraction, beveled recesses for specific angle light emission, and side walls for additional light management. This segmentation allows each region to optimize light extraction in its specific zone, collectively achieving high lumen output density while maintaining a compact overall structure.
Solution Approach 2:
Different regions of the encapsulation material are given different geometric properties: the top surface is flat for broadside emission, the beveled recesses have angled surfaces for directed light extraction, and the side walls provide lateral light management. This local differentiation of geometric quality optimizes light emission efficiency across the entire device without requiring complex external optics.
2Area of stationary object
If LED package size is reduced to increase lumen density, then space efficiency improves, but heat dissipation and electrical connection become more difficult
Solution Approach 1:
The electrical via structure is nested within the substrate thickness, with conductive paths extending from the bottom surface through the substrate to the top surface. This nesting approach allows electrical connections to be integrated within the compact package volume without increasing the external footprint, while maintaining reliable electrical connectivity to the LED chip.
Solution Approach 2:
Electrical connections are established not only through the top surface but also through the bottom surface via through-substrate vias. This three-dimensional electrical connection approach allows power and signal routing without consuming additional planar space, enabling compact packaging while maintaining electrical reliability.
3Illumination intensity
If more LEDs are packed into smaller area to increase lumen density, then light output increases, but manufacturing precision and light uniformity become more challenging
Solution Approach 1:
The encapsulation material serves multiple functions simultaneously: it provides mechanical support for multiple LEDs, manages light extraction from different angles through its geometric features, and ensures uniform light distribution across the device surface. This multi-functionality allows high-density LED packaging without compromising manufacturing feasibility or light uniformity.
Solution Approach 2:
The encapsulation material geometry is optimized with specific parameters: beveled recesses at defined angles, controlled depth-to-width ratios, and side wall configurations that promote uniform light extraction. These parameter optimizations ensure that even with multiple LEDs in close proximity, the light output remains uniform and manufacturable with standard precision.
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 results in brighter, more efficient, and cost-effective LED devices with improved light output and uniform emission, while maintaining a smaller package size, thereby increasing lumen density and reducing manufacturing costs.
Implementation Method 1
a light-transmissive encapsulation material disposed over the LEDs
Implementation Method 2
inefficient light emission due to internal reflections
Data Source
AI summary
Light emitting diode (LED) apparatuses and methods having a high lumen output density. An example apparatus can include a substrate with one or more LEDs enclosed by an encapsulant. The encapsulant comprises beveled edges and/or top surface facets. By providing facets in the encapsulant and minimizing the chip-to-area ratio through efficient via placement, a high lumen density is achieved. Facets and bevels can be created by removing material from the encapsulant with a beveled blade.