LED Package Bead Cover for Zener Diode Light Loss

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Solution Overview

Problem

Light-emitting diode (LED) packages experience reduced luminous efficiency and uneven light output due to light absorption by Zener diodes used for electrostatic discharge protection.

Innovation Solution

A light-emitting diode package design where a bead member, comprising beads dispersed in a translucent resin, covers the Zener diode to scatter light upward and sideward, minimizing absorption and enhancing light emission efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a Zener diode is used for electrostatic discharge protection, then the LED chip is protected against damage, but light absorption occurs leading to reduced luminous efficiency and uneven light output

Engineering Contradiction:
Improveelectrostatic discharge protectionVSAvoidluminous efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

A bead member is introduced as an intermediary component between the light-emitting diode chip and the Zener diode. This bead member covers the Zener diode and induces diffuse reflection of light that would otherwise be absorbed by the Zener diode, thereby protecting the LED chip while minimizing light absorption and maintaining luminous efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The bead member is selectively positioned to cover only the Zener diode component, creating a localized solution. The bead member includes beads that provide diffuse reflection specifically in the region where light absorption was problematic, without affecting other parts of the package structure

Inventive Principle:
Principle #3Local quality

2Reliability

If a Zener diode is mounted on the lead frame, then electrostatic discharge protection is provided, but uneven light distribution occurs due to light absorption by the Zener diode

Engineering Contradiction:
Improveelectrostatic discharge protectionVSAvoidlight output uniformity
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The bead member acts as a mediator that modifies the optical interaction between the LED chip and Zener diode. By covering the Zener diode with the bead member, light is diffusely reflected rather than absorbed, eliminating the dark spot effect and achieving uniform light distribution across the package

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The bead member alters the optical properties in the region of the Zener diode by introducing diffuse reflection. This changes the light distribution pattern from one with absorption-induced darkness to uniform diffuse reflection, improving overall light output uniformity

Inventive Principle:
Principle #32Color changes

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 improves light emission efficiency and uniformity by diffusely reflecting light from the LED chip, reducing the visibility of the Zener diode and eliminating uneven light distribution.

Implementation Method 1

the bead member includes beads inducing diffuse reflection of light emitted from the light-emitting diode chip and incident on the electrostatic discharge protection member

Methodology Applied
Scientific EffectDiffuse reflection: Reflection

Data Source

PatentEP4376107A1Light emitting diode package and manufacturing method of the same, and light emitting device
Publication Date: 2024.05.29 LG DISPLAY CO LTD
  • EP4376107A1 patent drawingFigure 1
  • EP4376107A1 patent drawingFigure 2
  • EP4376107A1 patent drawingFigure 3~4

AI summary

Embodiments relate to a light-emitting diode package (100) and a manufacturing method thereof and a light emitting device. The light-emitting diode package (100) includes a lead frame (110) comprising a substrate and leads formed on the substrate, a light-emitting diode chip (120) mounted on the lead frame (110) and electrically connected to the lead frame (110), an electrostatic discharge protection member (140) mounted on the lead frame (110) and electrically connected to the lead frame (110), a molding member (130) comprising a wall surrounding components of the light-emitting diode package (100), the wall attached to the outer periphery of the lead frame (110), and the wall defining a cavity together with the lead frame (110), and a bead member (150) covering a surface of the electrostatic discharge protection member (140), wherein the bead member (150) comprises beads (151) inducing diffuse reflection of light emitted from the light-emitting diode chip (120) and incident on the electrostatic discharge protection member (140).