Light Emitting Device Fluorescent Precipitation Method
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Light emitting devices with phosphor layers exhibit color unevenness and yellow rings due to limitations in electrode positioning and printing precision, particularly when using flip-chip assembly type light emitting elements, which restricts the size and distribution of fluorescent materials.
Innovation Solution
A method involving a fluorescent material precipitation process where a first resin layer with a filler is applied around the light emitting element, followed by a second resin layer with fluorescent material particles, allowing the particles to precipitate before curing, forming a layered structure that prevents color unevenness and yellow rings without requiring precise electrode positioning or printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a phosphor layer is formed around the light emitting element using electrode positioning or printing, then the fluorescent material can be distributed, but color unevenness and yellow rings occur due to limited particle diameter classification and printing precision
Solution Approach 1:
The patent applies preliminary action by pre-mixing the fluorescent material particles with the resin material before applying the composition to the light emitting element. This pre-mixing ensures uniform distribution of particles throughout the resin, eliminating the need for subsequent precise positioning or printing operations. The composition is then applied as a complete mixture, allowing the fluorescent material to be evenly distributed without requiring electrode positioning or printing precision, thus preventing color unevenness and yellow rings while simplifying the manufacturing process.
2Illumination intensity
If the phosphor layer size is increased to cover more area, then the light output is improved, but color unevenness and yellow rings become more pronounced
Solution Approach 1:
The patent applies local quality by ensuring that the fluorescent material particles are uniformly distributed throughout the entire phosphor layer composition before application. The pre-mixing process creates a homogeneous mixture where particle distribution is consistent across the entire area, regardless of the final layer size. This uniform distribution at the local level throughout the composition prevents color unevenness and yellow rings even when the phosphor layer is expanded to cover larger areas, thus improving light output without sacrificing color uniformity.
3Measurement precision
If electrode positioning is used to place fluorescent material particles, then precise positioning is achieved, but the process becomes more complex and costly
Solution Approach 1:
The patent applies self-service by using the natural properties of the fluorescent material particles and resin composition to achieve uniform distribution without requiring external positioning mechanisms. The pre-mixed composition is applied to the light emitting element, and the fluorescent material particles self-distribute uniformly throughout the resin matrix during application and curing. This eliminates the need for complex electrode positioning systems, reducing manufacturing process complexity and cost while still achieving the desired particle distribution and light output uniformity.
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 effectively prevents color unevenness and yellow rings in light emitting devices while reducing manufacturing costs, allowing for a more straightforward and cost-effective production process.
Implementation Method 1
a first layer comprising a transparent matrix material, wherein at least one of the layers contains one or more wavelength-converting substances dispersed in the matrix material and converting the blue light from the chip at least partially into light of a second wavelength
Implementation Method 2
a resin layer covering at least a portion of an inner surface of the recess of the body and having a higher reflectivity than the inner surface of the recess of the body
Data Source
Figure 1
Figure 2(a)~2(d)
Figure 3~4
AI summary
To provide a method for manufacturing a light emitting device capable of preventing color unevenness and a yellow ring from occurring at low cost, the method for manufacturing a light emitting device including a light emitting element and a resin layer containing fluorescent material particles and a filler which reflects light, wherein the method comprises a fluorescent material precipitation process for precipitating the fluorescent material particles in advance of the filler.