Stepped Semiconductor Laser Module Layout for Breakdown-Safe Miniaturization

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Solution Overview

Problem

Existing semiconductor laser modules face challenges in size reduction while preventing dielectric breakdown, as increasing the distance between electrode pads and step side surfaces to prevent breakdown results in an enlarged module.

Innovation Solution

A semiconductor laser module design with a stepped mount base and protruding upper semiconductor laser devices, which reduces the distance between devices, allowing for a smaller module size and incorporating an inhibition space to prevent dielectric breakdown, achieved through specific positioning structures and insulation calculations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the distance between electrode pads and step side surfaces is increased to prevent dielectric breakdown, then reliability is improved, but the module size increases

Engineering Contradiction:
Improvedielectric breakdown preventionVSAvoidmodule size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent applies dimensional change by forming a protrusion on the upper semiconductor laser device that extends in the vertical direction toward the lower device. This protrusion structure reduces the horizontal distance between electrode pads and step side surfaces, allowing the module to achieve compact size while maintaining adequate insulation distance for dielectric breakdown prevention.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The protrusion structure of the upper semiconductor laser device is positioned within the vertical space above the lower device, effectively utilizing the vertical dimension to reduce horizontal spacing requirements. This nesting approach allows compact arrangement while preserving necessary electrical insulation distances.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Volume of moving object

If the distance between upper and lower semiconductor laser devices is reduced for size reduction, then module size decreases, but dielectric breakdown risk increases

Engineering Contradiction:
Improvemodule sizeVSAvoiddielectric breakdown prevention
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

By introducing a protrusion in the vertical direction, the patent reduces the horizontal footprint of the upper device without compromising the vertical insulation distance. This allows closer horizontal spacing between upper and lower devices while maintaining dielectric breakdown prevention through adequate vertical clearance.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The protrusion is strategically positioned to extend only in regions where horizontal spacing needs reduction, while maintaining adequate vertical distance from the lower device in critical insulation areas. This localized structural modification optimizes space utilization without compromising reliability.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3736924B1Semiconductor laser module and method of manufacturing semiconductor laser module
Publication Date: 2024.01.31 FUJIKURA LTD
  • EP3736924B1 patent drawingFigure 1
  • EP3736924B1 patent drawingFigure 2
  • EP3736924B1 patent drawingFigure 3

AI summary

A semiconductor laser module that can achieve size reduction is provided. A semiconductor laser module 1 has an optical fiber 44 and semiconductor laser devices 30A-30E. Each of the semiconductor laser devices 30A-30E includes a semiconductor chip 31, electrode pads 32 and 33, and a mount 34. The semiconductor laser module 1 also has a mount base 20 having stepped mount surfaces 21A-21E on which the mounts 34 are mounted and an optical system that optically couples laser beams to an incident end face 44A of the optical fiber 44. The semiconductor laser devices 30A-30E include an upper semiconductor laser device 30C and a lower semiconductor laser device 30B disposed adjacent to each other in the Z-direction. A portion of the upper semiconductor laser device 30C protrudes from the mount surface 21C toward the lower semiconductor laser device 30B.