LED Package Structure with Curved Reflective Interface
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Solution Overview
Problem
Conventional LED package structures face challenges with large radiant angles, which are not suitable for applications like spotlights and backlights, and require a substrate, leading to integration issues and reduced light extraction efficiency.
Innovation Solution
A light emitting diode package structure with a first reflecting material layer, a flip chip, a first transparent material layer, and a wavelength conversion material layer, where the interface between the reflecting and transparent layers is inclined or arc-shaped for improved upward light reflection, and a fabrication method involving a fluorescent film and photo-etched metal sheet to create a bowl-shaped structure without a substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional LED package structure with a substrate and bonding wire is used, then the structure is stable and easy to manufacture, but the radiant angle becomes large which is not suitable for spotlight and backlight applications
Solution Approach 1:
The patent extracts and eliminates the substrate and bonding wire from the conventional LED package structure. The LED chip is directly mounted on the reflective cup structure, removing unnecessary components that contribute to large radiant angles and structural complexity while maintaining stability and manufacturability
Solution Approach 2:
The patent employs a reflective cup structure with specific curved surfaces (inclined planes, arc planes, or irregular shapes) to control light reflection. This curvature design enables precise control of the radiant angle for spotlight and backlight applications while simplifying the overall package structure
2Adaptability or versatility
If a glue wall structure is used to control light emission, then the radiant angle can be controlled, but the vertical glue wall is not good for upward light emitting and affects light extraction efficiency
Solution Approach 1:
The patent replaces the vertical glue wall with a reflective cup structure featuring inclined planes, arc planes, or irregular curved surfaces. These curved surfaces are optimized to reflect light upward and outward, improving both light emission direction control and light extraction efficiency by eliminating the blocking effect of vertical walls
Solution Approach 2:
The patent converts the potential harm of light being trapped or blocked by vertical structures into a benefit by using reflective surfaces that actively direct light upward. The reflective cup structure transforms what would be wasted or scattered light into useful upward-emitting light, improving overall light extraction efficiency
3Strength
If a large-size ceramic substrate is used to support the LED package, then the structure is stable, but integration becomes difficult and fabrication cost increases
Solution Approach 1:
The patent extracts and eliminates the large-size ceramic substrate from the package structure. The LED chip is directly mounted on a compact reflective cup structure, which provides sufficient mechanical support and thermal management without requiring a large substrate, thereby enabling easier integration and reducing fabrication costs
Solution Approach 2:
The patent merges the functions of the substrate, reflective surface, and structural support into a single integrated reflective cup structure. This consolidation eliminates the need for separate substrate components, simplifying the manufacturing process and improving integration while maintaining structural stability
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 achieves a flexible package structure with reduced thermal resistance, high lighting effect, and controlled light emitting angle, suitable for display systems and spotlights, while eliminating the need for a substrate, thus reducing fabrication costs and enhancing light extraction efficiency.
Implementation Method 1
a second reflecting material layer surrounding the first transparent material layer, the interface between the first transparent material layer and the reflecting material layer is an inclined plane, or an arc plane or an irregular shape, which is good for upward light reflection of the flip chip
Implementation Method 2
a wavelength conversion material layer covered over the above structure
Implementation Method 3
Light Emitting Diode (LED) is a semiconductor light-emitting device fabricated by adopting P-N junction electro-luminescence principle
Data Source
AI summary
A light emitting diode package structure allows for an improved light-emitting efficiency by including a first reflecting material layer with through holes; a flip chip on the first reflecting material layer, with the electrodes inlaid in the through holes of the first reflecting material layer; a first transparent material layer surrounding the side surface of the flip chip except the electrodes; and a second reflecting material layer surrounding the first transparent material layer. An interface between the first transparent material layer and the reflecting material layer is an inclined plane, an arc plane, or an irregular shape, to thereby facilitate upward light reflection of the flip chip. A wavelength conversion material layer is over the first reflecting material layer, the flip chip, and the second reflecting material layer.