LED Lumiphor Layer Layout for Uniform Color and Lower Light Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solid-state lighting devices face challenges in achieving high luminous efficacy and uniform color point due to light loss and non-uniformity caused by internal absorption and interaction of light emissions with lumiphoric materials and package elements.
Innovation Solution
The solution involves a solid-state light emitting device with a lumiphoric material layer applied over the outer surface of an LED, excluding lateral edges, and additional layers such as a fill material layer and a scattering material layer, along with a sealing template method for precise application of light-altering materials, ensuring uniform coverage and reduced light loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If lumiphoric material is applied over the entire LED surface including lateral edges, then light conversion coverage is improved, but light loss due to internal absorption increases and manufacturing precision deteriorates
Solution Approach 1:
The patent segments the LED surface into two distinct zones: a top surface region where lumiphoric material is applied for light conversion, and lateral edge regions where lumiphoric material is excluded to prevent light loss. This spatial segmentation allows optimized light management - converting light where needed while avoiding absorption losses at edges where light extraction is already compromised.
Solution Approach 2:
The patent applies different material qualities to different regions of the LED. The top surface receives lumiphoric material with specific optical properties for wavelength conversion, while the lateral edges are deliberately left without lumiphoric material to maintain light extraction efficiency. This local differentiation of material properties optimizes overall device performance by addressing the specific optical needs of each region.
2Loss of energy
If lumiphoric material layer is applied precisely excluding lateral edges, then light loss is reduced, but manufacturing precision and device complexity increase
Solution Approach 1:
The patent introduces a mask layer as an intermediary element during the lumiphoric material application process. This mask layer temporarily covers the lateral edge regions, preventing lumiphoric material from being applied there. The mask acts as a mediator that enables precise spatial control of material deposition without requiring complex direct patterning techniques, thus achieving the desired material distribution with manageable manufacturing precision.
3Manufacturing precision
If fill material layer is added to contact lateral surfaces, then manufacturing precision and light loss reduction are improved, but device complexity increases
Solution Approach 1:
The fill material layer serves multiple functions simultaneously: it provides mechanical support to the LED structure, defines the lateral boundaries for lumiphoric material application, and contributes to light extraction by filling void spaces. This multi-functionality reduces the need for separate dedicated components, thereby managing device complexity while achieving precise material placement and reduced light loss.
Solution Approach 2:
The patent merges the functions of structural support and optical boundary definition into a single fill material layer. Rather than using separate elements for mechanical support and for defining the lumiphoric material application zone, the fill material performs both roles concurrently. This consolidation simplifies the overall device architecture while maintaining the precision needed for optimal light management.
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 configuration enhances luminous efficacy and uniformity of color point over the emissive area while maintaining durability through coefficient of thermal expansion matching between components.
Implementation Method 1
Lumiphoric materials, such as phosphors, may be arranged in light emission paths of LED emitters to convert portions of light to different wavelengths
Implementation Method 2
a scattering material layer contacting lateral boundaries of the light-altering material layer
Data Source
AI summary
Solid state light emitting devices include at least one LED chip with a light-altering material arranged over an entire upper surface thereof, with lateral edges of the LED chip device of lumiphoric material, and at least one of a fill material layer contacting lateral surfaces of the LED chip or a scattering material layer contacting lateral surfaces of a light-altering material when the light-altering material is a lumiphoric material. A method for fabricating a solid state light emitting device comprises applying a fill material layer to contact lateral surfaces of a LED chip, adhering a sealing material template over the fill material, and applying a light-altering material through a window in the template to an upper surface of the LED chip, followed by removal of the template, optionally preceded by impingement of UV emissions to reduce adhesive tack and promote release of the template.