Wafer-Level LED Package With Concave Lens
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LED packages with dome lenses are impractical for full wafer level packaging due to their large size and high manufacturing costs, as they require a significant amount of transparent silicone material and have a large footprint, which is inefficient and costly.
Innovation Solution
A light emitting diode (LED) package design featuring a carrier substrate with a predefined surface area, an LED device bonded to it, and an encapsulant lens with a footprint matching the substrate's area, where the lens's top surface is inclined inwardly at an angle of 10° to 140°, forming a concave cone shape to enhance light extraction efficiency without the need for a large dome.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a large dome lens is used to enhance light extraction efficiency, then light extraction efficiency is improved, but the footprint area and volume of transparent silicone material increase significantly
Solution Approach 1:
The patent applies curvature to the encapsulant lens surface, using a concave spherical cap geometry instead of a flat surface. This curved surface configuration optimizes light extraction efficiency by controlling light propagation paths while maintaining a compact footprint, resolving the contradiction between light extraction performance and package size.
2Loss of energy
If a large dome lens is used to enhance light extraction efficiency, then light extraction efficiency is improved, but the volume of transparent silicone material increases significantly
Solution Approach 1:
The patent applies curvature to the encapsulant lens surface, using a concave spherical cap geometry instead of a flat surface. This curved surface configuration optimizes light extraction efficiency by controlling light propagation paths while maintaining a compact footprint, resolving the contradiction between light extraction performance and package size.
3Loss of energy
If a large dome lens is used to enhance light extraction efficiency, then light extraction efficiency is improved, but manufacturing cost increases
Solution Approach 1:
The patent changes the geometric parameters of the encapsulant lens, specifically using a concave spherical cap with controlled depth and radius ratios. This parameter optimization achieves high light extraction efficiency while reducing the overall lens volume and material requirements, thereby lowering manufacturing costs.
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 design achieves comparable light extraction efficiency to traditional dome-lensed packages while reducing the volume of silicone material required, making it more cost-effective and suitable for wafer level packaging.
Implementation Method 1
The encapsulant lens has a top surface inclined inwardly toward the top surface of the LED device
Implementation Method 2
the photons that are emitted downward from the LED to carrier substrate 104 are reflected back upwards by the metal bonding layer 103
Implementation Method 3
Phosphor-containing layer 214 modifies the wavelength of the light emitted by LED device 212 to 'whiten' the light emitted by LED package 200
Implementation Method 4
improved heat dissipation due to the use of a carrier substrate with high thermal conductivity
Data Source
AI summary
An LED package and method for LED packaging is disclosed. In one embodiment, an LED package includes a carrier substrate having a predefined surface area, an LED device bonded to the carrier substrate, the LED device having a footprint area of at least fifty percent of the predefined surface area of the carrier substrate, and an encapsulant lens having a top surface inclined inwardly at an angle in the range of about 10° to about 140°. In one embodiment, the top surface of the encapsulant lens layer has a concave cone shape. In one embodiment, a wafer level packaging process includes forming an encapsulant lens layer portion having a top surface inclined inwardly at an angle in the range of about 10° to about 140° on each of a plurality of LED devices bonded to a carrier substrate wafer.