PCSEL Bump-Bonded Light Source for Narrow Beam Divergence

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing light source apparatuses face challenges in narrowing beam divergence, reducing size, and minimizing inductance.

Innovation Solution

A light source apparatus is designed with a photonic crystal-surface emitting laser (PCSEL) that includes stacked layers, electrodes, and a laser driver connected through bumps for electrical connections, and a semiconductor substrate with a low-resistance layer, allowing direct bonding to a laser driver.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wire bonding is used to electrically couple PCSEL to laser driver, then electrical connection is achieved, but inductance increases and connection size increases

Engineering Contradiction:
Improveelectrical connectionVSAvoidconnection length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent extracts the long wire bonding connection and replaces it with direct bump bonding, removing the unnecessary intermediate connection structure. This extraction principle eliminates the inductive effect caused by long wires while maintaining electrical connectivity, directly resolving the contradiction between reliable electrical connection and minimized connection length/inductance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces bump structures as intermediary elements between the PCSEL and laser driver. These bumps serve as compact electrical connectors that replace the wire bonding method, providing reliable electrical connection with significantly reduced inductance and connection length compared to traditional wire bonding approaches.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If conventional light source apparatus structure is used, then manufacturing is straightforward, but beam divergence is large and device size is large

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidbeam divergence
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The patent merges the PCSEL active layer, photonic crystal layer, and electrode structures into a single integrated stacked configuration. This merging of functional layers enables direct control of beam divergence through the photonic crystal structure while maintaining manufacturing simplicity through a unified device architecture that can be fabricated using standard semiconductor processes.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the structural parameters of the light-emitting element by introducing a stacked layer configuration with specific photonic crystal structures. This parameter change enables control over beam divergence characteristics while maintaining ease of manufacture through compatibility with existing semiconductor fabrication techniques.

Inventive Principle:
Principle #35Parameter changes

3Shape

If PCSEL with stacked layers is used, then beam divergence is reduced, but device complexity increases

Engineering Contradiction:
Improvebeam divergenceVSAvoidstructure complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The patent segments the light-emitting element into distinct functional layers (active layer, photonic crystal layer, electrodes) stacked in a structured configuration. This segmentation allows each layer to perform its specific function optimally while the overall stacked structure manages complexity through modular organization, making the device both effective at reducing beam divergence and manufacturable using standard processes.

Inventive Principle:
Principle #1Segmentation

4Length of moving object

If direct bonding of PCSEL to laser driver is implemented, then inductance is reduced and size is reduced, but manufacturing precision requirements increase

Engineering Contradiction:
Improveconnection lengthVSAvoidbonding precision
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical wire bonding system with a direct bump bonding system that relies on controlled material deposition and thermal compression rather than mechanical wire manipulation. This substitution reduces the precision requirements for alignment and connection while achieving the goals of reduced inductance and compact size, as bump bonding is more tolerant to misalignment than wire bonding.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 solution achieves a reduction in beam divergence, size, and inductance, enabling high-speed operation and miniaturization.

Implementation Method 1

an active layer that emits laser light when an electric current passes therethrough

Methodology Applied
Scientific EffectStimulated emission: Laser

Implementation Method 2

a photonic crystal structure that brings an advantage in which it is possible to emit light having narrow beam divergence

Methodology Applied
Scientific EffectPhotonic crystal effect: Photonic Crystal

Implementation Method 3

electrically coupled to the photonic crystal-surface emitting laser through a bump

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4661223A1Light source device
Publication Date: 2025.12.10 SONY SEMICON SOLUTIONS CORP
  • EP4661223A1 patent drawingFigure 1
  • EP4661223A1 patent drawingFigure 2
  • EP4661223A1 patent drawingFigure 3

AI summary

A light source apparatus according to the present technology includes a photonic crystal-surface emitting laser and a laser driver. The photonic crystal-surface emitting layer includes at least one light-emitting element in which a plurality of layers is stacked. The plurality of layers includes an active layer and a photonic crystal layer. The laser driver is electrically coupled to the photonic crystal-surface emitting laser through a bump. With the light source apparatus according to the present technology, it is possible to provide a light source apparatus that makes it possible to narrow beam divergence of output light, and also to achieve a reduced size and a reduced inductance.