LED Package with Integrated Silicon Photodiode for Optical Feedback
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Solution Overview
Problem
Conventional LED packages with photo diodes suffer from low optical connection efficiency and reliability due to separate packaging and interference from external noise, which affects the stability of light output and peak wavelength.
Innovation Solution
Replacing the submount substrate with a silicon substrate and forming a photo diode on it, along with a partially reflective film, to enhance optical connection efficiency and integrate the photo diode and LED chip for improved feedback control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If photo diodes are arranged on separate lead frames adjacent to LEDs, then geometric adjacency is improved for side light absorption, but optical connection efficiency deteriorates due to physical separation
Solution Approach 1:
The patent merges the LED and photo diode onto a single lead frame, eliminating the physical separation between separate packages. The LED and photo diode are positioned adjacent to each other on the same lead frame, enabling direct optical coupling while maintaining geometric adjacency for effective side light absorption and monitoring.
2Ease of manufacture
If separate LED and photo diode packages are used, then manufacturing simplicity is improved, but reliability deteriorates due to noise interference from external environments
Solution Approach 1:
The patent combines both the LED and photo diode into a single integrated package on one lead frame. This merging approach maintains manufacturing simplicity while simultaneously improving detection reliability by shielding the photo diode from external noise interference through the common package structure.
3Reliability
If photo diode is integrated with LED on same substrate, then optical connection efficiency is improved, but device complexity increases
Solution Approach 1:
The patent integrates the photo diode with the LED on the same lead frame substrate, achieving high optical connection efficiency through direct adjacency. The integration is accomplished using standard lead frame materials and conventional positioning techniques, thereby minimizing the increase in device complexity while maximizing optical coupling.
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 optical connection efficiency and reliability by ensuring better light transmission and reducing noise interference, maintaining stable light output and peak wavelength.
Implementation Method 1
a photo diode formed in an upper part of the silicon substrate
Implementation Method 2
the light-receiving area of the photo diode may comprise a partially reflective film having a low light transmittance in accordance with desired light quantity
Data Source
AI summary
The present invention relates to an LED package including photo diode. The LED package includes a silicon substrate, and a photo diode is formed in an upper part thereof. Also, an insulation layer is formed on the silicon substrate excluding at least a light-receiving area of the photodiode. In the LED package, an LED terminal is formed on the insulation layer to be connected to the photo diode. First and second LED connecting pads are formed on the insulation layer, and arranged on both sides of the photo diode. In addition, an LED chip is mounted on the silicon substrate, and connected to the first and second LED connecting pads.