Semiconductor Light Emitting Device Transparent Layer Color Uniformity

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Solution Overview

Problem

Semiconductor light emitting devices with chip-size package structures face limitations in light output power and emission color consistency, particularly in achieving uniform light distribution and reducing color breakup.

Innovation Solution

The semiconductor light emitting device incorporates a semiconductor layer with a light emitting layer, a fluorescent substance layer, and a transparent layer made of transparent resin, where the fluorescent substance layer is positioned on top of the semiconductor layer and the transparent layer is interposed between the semiconductor and fluorescent substance layers, along with a metal film that reflects light to enhance light output and reduce color unevenness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a chip-size package structure is used, then device miniaturization is achieved, but light output power and emission color consistency deteriorate

Engineering Contradiction:
Improvedevice sizeVSAvoidlight output power
Core Design Contradiction:
Volume of moving objectVSIllumination intensity

Solution Approach 1:

The device is segmented into distinct functional layers: semiconductor layer, transparent layer, and fluorescent substance layer. This segmentation allows each layer to perform its specific function optimally while maintaining a compact overall structure, resolving the contradiction between miniaturization and light output power.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a conventional planar structure to a vertical stacked structure with multiple layers arranged in the thickness direction. This dimensional reorganization increases light extraction efficiency and output power without increasing the planar footprint, thus maintaining device miniaturization.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If a chip-size package structure is used, then device miniaturization is achieved, but emission color consistency deteriorates

Engineering Contradiction:
Improvedevice sizeVSAvoidemission color consistency
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The transparent layer acts as an intermediary between the semiconductor layer and fluorescent substance layer. It controls light transmission and interaction, ensuring uniform excitation of the fluorescent material and consistent emission color across the device area while maintaining compact dimensions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Each layer is designed with specific local properties: the transparent layer has optimized refractive index and thickness for uniform light distribution, and the fluorescent substance layer has controlled composition and thickness. These localized quality optimizations ensure consistent emission color throughout the device.

Inventive Principle:
Principle #3Local quality

3Illumination intensity

If transparent layer and fluorescent substance layer are added, then light output power and color consistency improve, but device complexity increases

Engineering Contradiction:
Improvelight output powerVSAvoidstructure complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

Multiple functional layers (semiconductor layer, transparent layer, fluorescent substance layer) are merged into a single integrated stacked structure. This consolidation achieves enhanced light output and color consistency while maintaining a compact form factor, balancing performance improvement with structural simplicity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The transparent layer serves multiple functions simultaneously: it acts as an optical waveguide, a structural support, and a interface for light extraction. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 improves light output power by minimizing light absorption and enhances emission color consistency by suppressing color breakup and color unevenness, resulting in a more efficient and uniform light emission.

Implementation Method 1

the transparent layer transmitting the light emitted from the light emitting layer

Methodology Applied
Scientific EffectLight transmission: Refraction

Implementation Method 2

includes a fluorescent substance radiating light different in a wavelength from light emitted from the light emitting layer

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 3

a metal film that reflects light to enhance light output and reduce color unevenness

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP2919283B1Semiconductor light emitting device
Publication Date: 2020.09.09 SAMSUNG ELECTRONICS CO LTD
  • EP2919283B1 patent drawingFigure 1
  • EP2919283B1 patent drawingFigure 2A~2B
  • EP2919283B1 patent drawingFigure 3A~3B

AI summary

A semiconductor light emitting device (1-9;10;11) includes a semiconductor layer (15), a p-side interconnect portion (41), an n-side interconnect portion (43), a fluorescent substance layer (30) and a transparent layer (70,170,270;370). The semiconductor layer (15) has a first major surface (15a), a second major surface (15b), and a first side surface, the semiconductor layer (15) including a light emitting layer (13). The p-side and n-side interconnect portions (41,43) are electrically connected to the semiconductor layer (15). The fluorescent substance layer (30) is provided on the first major surface side. The transparent layer (70,170,270;370) is provided between the semiconductor layer (15) and the fluorescent substance layer (30), and has a second side surface. The semiconductor light emitting device (1-9;10;11) further includes an insulating film (18) covering the first side surface and the second side surface, and a reflecting member covering the first side surface and the second side surface via the insulating film (18).