Slant-Sided Reflective Layer for High-Efficiency Semiconductor Light Emitting Device
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Solution Overview
Problem
Conventional semiconductor light-emitting devices face challenges in achieving high light-emitting efficiency from a small light-emitting surface, particularly when used in applications like vehicle headlights, due to issues with light reflection and absorption by the reflecting member, which reduces the total light flux emitted.
Innovation Solution
The semiconductor light-emitting device incorporates a base board with conductor patterns, semiconductor light-emitting chips connected via solder bumps, a wavelength converting layer with phosphors, a transparent material layer, and a reflective material layer with a side slant surface that extends from the semiconductor light-emitting chip to the wavelength converting layer, optimizing light reflection and emission from a small surface area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional reflecting member with a perpendicular side surface is used, then the device structure is simple, but light emitted from the side surface of the semiconductor light-emitting chip is reflected back and absorbed by the chip, reducing light-emitting efficiency
Solution Approach 1:
The reflecting member's side surface is designed with a slant angle (5-75 degrees) rather than being perpendicular to the base board. This asymmetric configuration prevents light reflected from the side surface from returning to the semiconductor light-emitting chip, thereby eliminating light absorption losses and improving light-emitting efficiency without significantly complicating the device structure
Solution Approach 2:
The invention changes the geometric parameter of the reflecting member's side surface from a perpendicular angle (90 degrees) to a slant angle range (5-75 degrees). This parameter modification optimizes the light reflection path, ensuring that reflected light does not re-enter the semiconductor chip, thus resolving the contradiction between maintaining structural simplicity and improving light-emitting efficiency
2Area of stationary object
If the light-emitting surface is reduced for use in vehicle headlights, then the optical structure can be smaller, but conventional devices cannot achieve high light-emitting efficiency from such a small surface
Solution Approach 1:
The slant-sided reflecting member creates an asymmetric light reflection path that directs light effectively toward the frontward direction. This allows the device to maintain a small light-emitting surface area while preventing light loss through absorption, thereby achieving high light-emitting efficiency from a compact surface suitable for vehicle headlight applications
Solution Approach 2:
The reflecting member is positioned locally around the semiconductor light-emitting chip with its slant side surface specifically oriented to reflect light from the chip's side surface. This localized optimization of light reflection in the critical region enables high efficiency from a small overall light-emitting surface area
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 light-emitting efficiency by preventing light absorption and ensuring efficient light reflection, resulting in a semiconductor light-emitting device that emits wavelength-converted light with high efficiency from a small light-emitting surface, suitable for applications like vehicle headlights.
Implementation Method 1
a wavelength converting layer 14 having a top surface, a bottom surface and a side surface located over the top surface of the semiconductor light-emitting chip 11, and the top surface and bottom surface thereof being slightly larger than the top surface of the semiconductor light-emitting chip 11
Implementation Method 2
a reflective material layer 15 made of a material having a high reflectivity, disposed between the frame 16 and side surfaces of the wavelength converting layer 14 and the transparent material layer 13 and disposed between the bottom surface of the semiconductor light-emitting chip 11 and the mounting surface of the base board 10
Data Source
AI summary
A semiconductor light-emitting device and a method for manufacturing the same can include a wavelength converting layer located over at least one semiconductor light-emitting chip in order to emit various colored lights including white light. The semiconductor light-emitting device can include a base board, a frame located on the base board, the chip mounted on the base board, a transparent material layer located between the wavelength converting layer and a side surface of the chip so as to extend toward the wavelength converting layer, and a reflective material layer disposed at least between the frame and both side surfaces of the wavelength converting layer and the transparent material layer. The semiconductor light-emitting device can be configured to improve light-emitting efficiency of the chip by using the reflective material layer as a reflector, and therefore can emit a wavelength-converted light having a high light-emitting efficiency from a small light-emitting surface.