LED Package Sidewall Optical Spacer Prevents Yellowing
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Solution Overview
Problem
The sidewall of the insulating layer in LED packages yellows when exposed to light, leading to reduced brightness and reliability of the light-emitting device due to light absorption.
Innovation Solution
A metal substrate-based light-emitting device package with an insulating layer having openings for LEDs, where the sidewalls of these openings are covered with an optical spacer made from a photosensitive material like dry film photoresist to prevent yellowing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the insulating layer sidewall is exposed without coating, then the manufacturing process is simple, but the sidewall yellows and absorbs light reducing LED brightness
Solution Approach 1:
The patent introduces an optical spacer as an intermediary substance coating the insulating layer sidewall. This optical spacer acts as a mediator between the insulating layer and the LED light, preventing direct interaction that causes yellowing while maintaining manufacturing feasibility through coating processes
Solution Approach 2:
The patent applies preliminary protective action by coating the insulating layer sidewall with optical spacer material before LED operation begins. This pre-protection prevents the yellowing reaction from occurring in the first place, rather than attempting to correct it after degradation
2Reliability
If the insulating layer sidewall is coated with optical spacer, then light absorption is prevented and brightness is maintained, but the manufacturing process becomes more complex
Solution Approach 1:
The patent modifies the surface properties of the insulating layer by changing its optical parameters through coating. By altering the surface composition to include optical spacer material with different optical characteristics, the sidewall resists yellowing while the added manufacturing step uses standard coating techniques
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 optical spacer effectively mitigates brightness decay and enhances the reliability of the light-emitting device package by preventing sidewall yellowing and maintaining light emission efficiency.
Implementation Method 1
An optical spacer covers a sidewall of the at least one opening of the insulating layer... the optical spacer effectively mitigates brightness decay and enhances the reliability of the light-emitting device package by preventing sidewall yellowing
Data Source
AI summary
A light-emitting device package is disclosed. The light-emitting device package includes a metal substrate. An insulating layer is on the metal substrate, wherein the insulating layer has at least one opening to expose the metal substrate. At least one light-emitting device is disposed in the at least one opening of the insulating layer. A sidewall of the at least one opening of the insulating layer is covered by an optical spacer. The disclosure also provides a method for manufacturing the light-emitting device package.