LED Package Recess and Reflective Wall for Lateral Light Control
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Solution Overview
Problem
Flip chip type LEDs emit light from both the upper surface and side surfaces, requiring techniques to control lateral light emission effectively to meet demands for high luminance efficiency and color quality within specific color tolerance levels, such as the MacAdam ellipse level 3 step, which existing methods fail to achieve efficiently.
Innovation Solution
A light emitting device package is designed with a base having a recess to house the LED, surrounded by a reflective wall that extends between the LED and the base, along with a wavelength conversion layer that covers the LED's upper surface and extends laterally, using a metal plate with an insulating layer and white molding compounds to control side light emission and prevent leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a flip chip type LED is used to achieve high luminance efficiency and simple structure, then heat dissipation characteristics and manufacturing simplicity are improved, but lateral light emission occurs causing color quality degradation and requiring complex control techniques
Solution Approach 1:
The patent extracts and addresses the lateral light emission problem by introducing a specific recess structure with depth between 80% to 120% of the LED height. This recess confines the LED and controls the path of laterally emitted light, separating the lateral emission control function from the overall package structure without changing the flip chip LED itself.
Solution Approach 2:
The patent applies local quality by creating a recess with specific depth characteristics (80%-120% of LED height) at the location where the LED is mounted. This localized structural modification controls the lateral light emission precisely where it occurs, while maintaining the simplicity of the flip chip structure elsewhere.
2Manufacturing precision
If techniques are added to control lateral phosphor layer to achieve MacAdam ellipse level 3 color quality, then color quality is improved, but device complexity increases
Solution Approach 1:
The patent changes the geometric parameter of the recess depth to a specific range (80%-120% of LED height) to optimize lateral light control. This parameter optimization achieves effective lateral emission control and MacAdam ellipse level 3 color quality without requiring additional complex components or control mechanisms.
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 configuration enhances luminance efficiency by controlling side light emission, maintaining color quality within specified tolerance levels by reflecting lateral light and minimizing color dispersion, thus improving the overall performance of illumination products.
Implementation Method 1
a reflective wall filling a space between the light emitting device and the recess so as to surround lateral surfaces of the light emitting device
Implementation Method 2
a wavelength conversion layer disposed on the light emitting device
Data Source
AI summary
A light emitting device package includes a base including at least one recess, at least one light emitting device disposed within the recess, and a reflective wall filling a space between the light emitting device and the recess so as to surround lateral surfaces of the light emitting device. The recess is formed to have a depth ranging from 80% to 120% of a height of the light emitting device.