Light-emitting Device Phosphor Film Compression Molding
Solution Overview
Problem
The existing methods for manufacturing light-emitting devices with a phosphor layer struggle to form a phosphor layer of desired thickness, leading to difficulties in controlling phosphor distribution and extracting light with a desired wavelength.
Innovation Solution
A method involving a phosphor-containing film placed on a mold with a concave portion, where a resin material is applied and subjected to pressure and heat, forming a transparent sealing resin and a phosphor-containing layer with a concavo-convex surface, allowing for precise control over the phosphor layer thickness and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a phosphor slurry is applied to the surface of the transparent sealing resin, then the phosphor layer can be formed, but it is difficult to control the thickness and distribution of the phosphor layer
Solution Approach 1:
The patent changes the physical state and application method of the phosphor layer from a liquid slurry to a solid film. The phosphor-containing film is placed on the mold surface before compression molding, allowing precise thickness control through film selection while simplifying the manufacturing process through integration into the molding step.
2Ease of manufacture
If a separate release film is used during compression molding, then the molded product can be easily released, but the device complexity and manufacturing steps increase
Solution Approach 1:
The patent merges the phosphor-containing film with the release film function. The phosphor-containing film is placed on the mold surface and serves dual purposes: as the source of the phosphor layer and as the release film during compression molding, eliminating the need for a separate release film.
Solution Approach 2:
The phosphor-containing film performs multiple functions: it serves as the phosphor layer source, acts as a release film during molding, and provides the desired thickness control. This multi-functionality reduces the total number of components and simplifies the manufacturing process.
3Device complexity
If phosphor is uniformly distributed in the transparent sealing resin, then the sealing is simplified, but light path length unevenness and color unevenness occur
Solution Approach 1:
The patent segments the phosphor distribution into two distinct regions: the transparent sealing resin remains phosphor-free for uniform optical properties, while the phosphor is concentrated in a separate layer on the mold surface. This segmentation allows each region to fulfill its specific function without compromising the other.
Solution Approach 2:
The patent applies local quality by placing phosphor only in specific locations (on the mold surface where the phosphor-containing film is positioned) rather than uniformly throughout the entire sealing resin. This localized phosphor distribution enables precise control over where light conversion occurs, ensuring uniform color output.
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 enables the production of light-emitting devices that can extract light with a desired wavelength, reducing manufacturing costs and improving color reproducibility by simultaneously forming the transparent sealing resin and phosphor-containing layer through compression molding.
Implementation Method 1
applying pressure and heat to the resin material and the phosphor-containing film, thereby forming a transparent sealing resin for sealing the light-emitting element and a phosphor-containing layer covering a surface thereof
Implementation Method 2
an electron in phosphor in the phosphor layer is excited by light emitted from the LED chip and produces fluorescence
Data Source
AI summary
A method of manufacturing a light-emitting device includes placing a phosphor-containing film on a mold for compression molding, the mold having a concave portion of a predetermined shape and the film being placed along an inner wall of the concave portion, supplying a resin material on the phosphor-containing film in the concave portion, immersing a light-emitting element mounted on a substrate in the resin material in the concave portion, and applying pressure and heat to the resin material and the phosphor-containing film, thereby forming a transparent sealing resin for sealing the light-emitting element and a phosphor-containing layer covering a surface thereof.