Semiconductor Light Emitting Element with Localized Convex Regions

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Solution Overview

Problem

Conventional semiconductor light emitting devices with concaves/convexes on the light extraction surface face issues of electrode peeling-off and poor light distribution, particularly when attempting to increase light output and extraction efficiency, as uniform concave/convex structures can lead to electrode detachment and inadequate light directionality.

Innovation Solution

A semiconductor light emitting device configuration featuring a first area with high, deep concaves/convexes and a second area with low, shallow concaves/convexes on the light extraction surface, where the second area is adjacent to the electrode, reduces electrode peeling-off and improves light distribution by tapering the top ends and arranging the second area to surround the electrode, thereby enhancing light extraction efficiency and output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If uniform concaves/convexes are formed on the light extraction surface to increase light extraction efficiency, then light output is improved, but electrode peeling-off occurs

Engineering Contradiction:
Improvelight extraction efficiencyVSAvoidelectrode adhesion
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by creating two distinct regions with different concave/convex characteristics: a first region with deeper concaves/convexes for high light extraction efficiency, and a second region with shallower concaves/convexes adjacent to the electrode for reliable electrode adhesion. This spatial differentiation of structural properties resolves the contradiction between light output and electrode stability.

Inventive Principle:
Principle #3Local quality

2Productivity

If deep concaves/convexes are formed to maximize light output, then light extraction efficiency is improved, but light distribution becomes poor

Engineering Contradiction:
Improvelight outputVSAvoidlight distribution
Core Design Contradiction:
ProductivityVSIllumination intensity

Solution Approach 1:

The patent differentiates the light extraction surface into two regions: the first region with deep concaves/convexes maximizes light output, while the second region with shallow concaves/convexes adjacent to the electrode provides better light distribution. The complementary roles of these regions resolve the contradiction between light output and light distribution quality.

Inventive Principle:
Principle #3Local quality

3Productivity

If concaves/convexes are formed to improve light extraction, then light emission efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvelight emission efficiencyVSAvoidstructure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the light extraction surface into two functional regions with different concave/convex depths, allowing each region to optimize for its specific purpose while maintaining overall manufacturing feasibility through a unified formation process.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2234182B1Semiconductor light emitting element and method for manufacturing the same
Publication Date: 2016.11.09 NICHIA CORP
  • EP2234182B1 patent drawingFigure 1
  • EP2234182B1 patent drawingFigure 2
  • EP2234182B1 patent drawingFigure 3~4

AI summary

A semiconductor light emitting device having high reliability and excellent light distribution characteristics is provided. Specifically, a semiconductor light emitting device 1 is provided with an n-electrode 50, which is arranged on a light extraction surface on the side opposite to the surface whereupon a semiconductor stack 40 is mounted on a substrate 10. A plurality of convexes are arranged on a first convex region 80 and a second convex region 90 on the light extraction surface. The second convex region 90 adjoins to the interface between the n-electrode 50 and the semiconductor stack 40, between the first convex region 80 and the n-electrode 50. The base end of the first convex arranged in the first convex region 80 is positioned closer to a light emitting layer 42 than the interface between the n-electrode 50 and the semiconductor stack 40, and the base end of the second convex arranged in the second convex region 90 is positioned closer to the interface between the n-electrode 50 and the semiconductor stack 40 than the base end of the first convex.