Columnar Light-Emitting Structure for Easier Flip-Chip Mounting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light-emitting devices with semiconductor lasers face challenges in flip-chip mounting due to significant differences in electrode positions, which hinder efficient light emission and mounting processes.
Innovation Solution
A light-emitting device design featuring a substrate, columnar portions with specific semiconductor layers and electrodes, and a conductive member that reduces positional differences between electrodes, enabling easier flip-chip mounting and enhancing light emission efficiency through a photonic crystal effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If flip-chip mounting is performed with large difference between electrode positions, then light emission can be achieved, but mounting becomes difficult and positioning precision deteriorates
Solution Approach 1:
An insulating layer with first and second electrode contact portions is introduced as an intermediary component between the electrodes and the external circuit. This insulating layer serves as a mediator that allows electrodes at different positions to be electrically connected while maintaining proper spacing for flip-chip mounting, thus resolving the contradiction between ease of mounting and electrode position difference
Solution Approach 2:
The solution transitions from a planar electrode arrangement to a three-dimensional structure by stacking the insulating layer between the first and second electrodes. This vertical stacking in another dimension (z-direction) allows the electrodes to be positioned at different heights while maintaining horizontal spacing suitable for mounting, thereby resolving the position difference issue
2Ease of operation
If electrode positions are kept close for easy mounting, then mounting becomes easier, but light extraction efficiency may be compromised
Solution Approach 1:
The insulating layer is designed with different local properties: the first electrode contact portion has a first dielectric constant optimized for electrical connection with the first electrode, while the second electrode contact portion has a second dielectric constant optimized for light extraction efficiency. This local quality differentiation allows simultaneous optimization for both ease of mounting and light extraction
Solution Approach 2:
The dielectric constant parameter of the insulating layer is varied spatially - the first electrode contact portion has one dielectric constant value while the second electrode contact portion has another. This parameter change allows the structure to optimize both electrical connection (for easy mounting) and optical performance (light extraction) in different locations
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 design facilitates easier flip-chip mounting and increases light emission intensity by reducing electrode position differences and utilizing a conductive member to enhance light extraction efficiency.
Implementation Method 1
a light-emitting layer provided between the first semiconductor layer and the second semiconductor layer
Implementation Method 2
a semiconductor laser to which nanocolumns are applied is expected to be capable of realizing high-output light emission at a narrow radiation angle by an effect of a photonic crystal due to a periodic arrangement of the nanocolumns
Data Source
AI summary
A light-emitting device includes a substrate; a first semiconductor portion having a first conductivity type; a first columnar portion and a second columnar portion each including a second semiconductor portion having a second conductivity type different from the first conductivity type, a third semiconductor portion having the first conductivity type, and a quantum well layer; a first electrode; a second electrode; and a conductive member electrically coupling the second electrode and the first semiconductor portion. Each of the first columnar portion and the second columnar portion protrudes from the first semiconductor portion toward a side of the substrate. The first electrode is electrically coupled to the second semiconductor portion of the first columnar portion. The second electrode is electrically coupled to, via the conductive member and the first semiconductor portion, the third semiconductor portion of the first columnar portion.