Optical Coupling Structure with Non-Plated Submount Region

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Solution Overview

Problem

Conventional semiconductor laser modules face issues with burr formation during submount cutting, which obstructs light emission and affects the accuracy and stability of semiconductor laser placement, leading to potential heat transmission inefficiencies and interference with optical fibers.

Innovation Solution

An optical coupling structure is developed with a submount featuring a non-plated region and an intermediate layer softer than the submount and semiconductor laser, positioned to set back from the end, allowing efficient optical coupling and heat transfer while preventing interference between the optical fiber and submount.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the plating layer is formed close to the end of the submount to improve heat transmission efficiency, then heat dissipation is improved, but burr formation during cutting obstructs light emission and causes placement inaccuracies

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidplacement accuracy

Core Design Contradiction:

TemperatureVSManufacturing precision

Solution Approach 1:

The plating layer is extracted from the end region of the submount, creating a non-plated region at the cutting part. This removes the source of burr formation from the critical optical path while preserving heat transmission through the plated regions closer to the semiconductor laser mounting area.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Different regions of the submount are assigned different properties: the end region has no plating to prevent burrs, while regions closer to the mounting area have plating for optimal heat transmission. This local differentiation resolves the contradiction between heat dissipation and manufacturing precision.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If the non-plated region is formed to prevent burr formation, then manufacturing precision is improved, but the semiconductor laser must be positioned farther from the end, reducing optical coupling efficiency

Engineering Contradiction:

Improveplacement accuracyVSAvoidoptical coupling efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The problem is resolved by transitioning from a one-dimensional trade-off (distance from end) to a two-dimensional solution: the non-plated region is positioned at the end while plated regions extend toward the mounting area, allowing the semiconductor laser to be mounted on plated regions for heat dissipation while maintaining proximity to the optical fiber for coupling efficiency.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The intermediate region with plating serves as a mediator between the non-plated end region and the semiconductor laser mounting position, enabling both burr prevention and efficient heat transmission while allowing optimal positioning for optical coupling.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If the semiconductor laser is positioned close to the end for optimal optical coupling, then optical coupling efficiency is improved, but the plating layer must extend to the end, causing burr formation

Engineering Contradiction:

Improveoptical coupling efficiencyVSAvoidburr obstruction

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The plating layer is extracted from the end region where the semiconductor laser is positioned for optical coupling, eliminating burr formation in the critical optical path while allowing the laser to maintain its optimal position for coupling efficiency.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The end region where optical coupling occurs has no plating to prevent burrs, while other regions have plating for heat transmission, allowing the semiconductor laser to be positioned optimally for coupling without suffering from burr obstruction.

Inventive Principle:

Principle #3Local quality

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

This structure enables efficient optical coupling between the semiconductor laser and optical fiber, prevents burr formation, ensures accurate placement, and provides effective heat dissipation by using a copper intermediate layer as a buffer and heat conductor.

Implementation Method 1

provides effective heat dissipation by using a copper intermediate layer as a buffer and heat conductor

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS10670819B2Optical coupling structure between optical fiber and semiconductor laser

Publication Date: 2020.06.02 FURUKAWA ELECTRIC CO LTD

AI summary

A non-plated region is formed in a certain range from an end of a submount. The non-plated region is a portion where a plating layer is not provided, and thus a substrate of the submount is exposed. An intermediate layer is formed on the plating layer. Furthermore, a plating layer is formed on the intermediate layer. A semiconductor laser is formed on the plating layer. The position of an end of the semiconductor laser substantially coincides with the position of an end of the plating layer (the intermediate layer). That is, even in a case where there is a deviation between an end face of the intermediate layer and an end face of the semiconductor laser, the amount of this deviation is sufficiently smaller than the amount by which the intermediate layer is set back from an end face of the submount.