Thin Semiconductor Light Emitter Electrode Layout for Stress Reliability

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Solution Overview

Problem

Semiconductor light emitting devices face reliability issues due to stress concentration between electrodes, leading to damage and deterioration, and struggle with achieving both thinness and optimal luminous flux.

Innovation Solution

A semiconductor light emitting element with a flat plate-shaped translucent element substrate, a laminated light emitting semiconductor layer, and electrodes separated by an insulating film, where the element substrate is thinned to 100 μm or less to improve mechanical strength and light output while maintaining reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the element substrate is thinned to achieve space saving, then the thickness is reduced, but stress concentration occurs between electrodes causing reliability deterioration

Engineering Contradiction:

Improvethickness of element substrateVSAvoidreliability of semiconductor light emitting element

Core Design Contradiction:

Length of moving objectVSReliability

Solution Approach 1:

The patent addresses the stress concentration problem by redistributing electrodes in multiple dimensions: element electrodes are arranged in a matrix pattern (rows and columns) rather than simple linear arrangement, and connection electrodes are distributed across multiple positions on the mounting substrate. This multi-dimensional electrode layout reduces stress concentration points while maintaining electrical connectivity in thinned substrates

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent segments the electrode system into multiple independent elements: multiple element electrodes (first and second conductive type) are divided into separate groups, and connection electrodes are segmented into multiple positions. This segmentation prevents stress concentration between any single pair of electrodes and distributes mechanical loads across multiple connection points, improving reliability in thinned substrates

Inventive Principle:

Principle #1Segmentation

2Length of moving object

If the element substrate is thinned to achieve space saving, then the thickness is reduced, but mechanical strength deteriorates

Engineering Contradiction:

Improvethickness of element substrateVSAvoidmechanical strength of element substrate

Core Design Contradiction:

Length of moving objectVSStrength

Solution Approach 1:

The patent employs composite material structures: the element substrate is combined with multiple electrode layers (n-type, p-type, insulating films), and the mounting substrate integrates base material with wiring layers and connection electrodes. This composite structure distributes mechanical stresses across different material layers, maintaining overall strength even when the element substrate is thinned to 100 μm or less

Inventive Principle:

Principle #40Composite materials

3Illumination intensity

If the element substrate is thinned to improve light output, then the thickness is reduced, but stress concentration causes damage to semiconductor layer

Engineering Contradiction:

Improveluminous fluxVSAvoidstress concentration

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces insulating films as intermediary layers between the n-type and p-type semiconductor layers and between electrodes. These intermediary insulating layers electrically isolate conductive elements while mechanically distributing stresses, preventing direct stress concentration on the semiconductor light emitting layer even when the substrate is thinned to enhance light output

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20250015233A1Semiconductor light emitting element and light emitting device

Publication Date: 2025.01.09 STANLEY ELECTRIC CO LTD

AI summary

A semiconductor light emitting element (10) includes flat plate-shaped translucent element substrate (11) with two main surfaces (11A, 11B) facing each other, light emitting semiconductor layer (12) formed on one main surface (11A) of element substrate (11) and in which n-type semiconductor layer (13), light emitting layer (14), and p-type semiconductor layer (15) are laminated, n-electrode (16) connected to n-type semiconductor layer (13) through at least one hole portion (12A) leading to n-type semiconductor layer (13) and provided on p-type semiconductor layer (15) being electrically separated from p-type semiconductor layer (15) by insulating film (18), first element electrode (19) electrically connected to n-electrode (16) and provided to extend in first direction, and second element electrode (20) electrically connected to p-type semiconductor layer (15) and provided to extend in first direction while being spaced apart from first element electrode (19), where thickness of element substrate (11) is 100 μm or less.