UV LED Package Structure Using Fluororesin to Cut Reflection Loss
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Solution Overview
Problem
Conventional UV LED packaging structures suffer from reduced light output efficiency due to total reflection at the interface between the LED chip and optical element, and issues with bubble formation and adhesion during the filling process using amorphous fluorine-containing resin materials.
Innovation Solution
A light-emitting packaging device featuring a substrate, an LED chip, an optical element, and a covering member made from a fluorine-containing resin that covers the LED chip and optical element, reducing total reflection and enhancing adhesion by filling the space between them, thereby increasing light output efficiency and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If amorphous fluorine-containing resin material is used to fill the space between LED chip and optical element, then light output efficiency is improved, but bubbles are difficult to be released and adhesion is reduced
Solution Approach 1:
The patent changes the physical state of the fluorine-containing resin from liquid to solid by controlling the reflow process. The resin is applied in solid form rather than liquid form, which eliminates bubble formation while maintaining the refractive index matching properties that improve light output efficiency. This parameter change (from liquid to solid application state) resolves the contradiction between improving light efficiency and ensuring reliability.
Solution Approach 2:
The patent uses a solid fluorine-containing resin that replicates the optical benefits of the liquid resin (refractive index matching) without the harmful effects (bubbles, poor adhesion). The solid resin copy maintains the essential optical property (refractive index) while eliminating the manufacturing defects associated with liquid application.
2Illumination intensity
If optical element is spacedly disposed on LED chip, then light transmission is enabled, but total reflection occurs at the interface reducing light output efficiency
Solution Approach 1:
The patent introduces a fluorine-containing resin as an intermediary material between the LED chip and the optical element. This resin layer has a refractive index that matches both the LED chip and the optical element, serving as an optical mediator that eliminates total internal reflection at the interfaces and enables efficient light transmission from the LED chip through the optical element.
3Loss of energy
If filling member is made from liquid amorphous fluorine-containing resin, then total reflection is reduced, but adhesion between optical element and filling member is reduced
Solution Approach 1:
The patent changes the application state of the fluorine-containing resin from liquid to solid. By applying the resin in solid form and using reflow processing, the patent achieves both good adhesion strength and total reflection reduction, eliminating the adhesion problems associated with liquid resin application while maintaining the optical benefits.
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
The solution effectively increases light output efficiency and reliability by minimizing total reflection and ensuring proper adhesion between components, while also preventing bubble formation and deformation during the reflow process.
Implementation Method 1
light emitted from the LED chip first enters into the air space between the LED chip and the optical element, and is then transmitted to outside of the packaging structure through the optical element. That is, the emitted light is transmitted from one medium (e.g., optically denser medium) to another medium (e.g., optically thinner medium), which may cause total reflection, and thus greatly decreases light output efficiency
Implementation Method 2
the amorphous fluorine-containing resin material for filling the space between the LED chip 92 and the optical element 94 is in a liquid form, and might have bubbles that are difficult to be released, which might adversely affect the light output efficiency of the resultant LED packaging structure
Data Source
AI summary
A light-emitting packaging device includes a substrate, a light-emitting diode (LED) chip, an optical element, and a covering member. The LED chip is disposed on the substrate. The optical element is spacedly disposed on the LED chip opposite to the substrate, and has an upper surface and a lower surface that are respectively distal from and proximal to the LED chip. The covering member is made from a fluorine-containing resin, and is configured to cover the LED chip and at least a portion of the upper surface of the optical element.