Solder-Free Laser Stripe Submount with Trench

Solution Overview

Problem

Existing semiconductor laser bonding methods with solder can introduce mechanical and thermal stresses, impairing optical coupling and dimensional tolerances due to direct contact with the laser active stripe, which affects the performance of optical circuits.

Innovation Solution

A submount design with raised surfaces and a trench between electrical contacts prevents solder or conductive epoxy from contacting the laser active stripe, reducing mechanical and thermal stresses by arranging the laser active stripe in a facing relationship with the submount, thus avoiding direct contact and potential electrical shorts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the semiconductor laser is bonded with the laser active stripe facing away from the submount, then mechanical and thermal stresses are avoided, but dimensional tolerances increase and optical coupling is impaired

Engineering Contradiction:

Improvemechanical and thermal stress avoidanceVSAvoiddimensional tolerances

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The submount surface is segmented into a bonding surface and a facing surface separated by a trench. The trench divides the space between electrical contacts, allowing the laser active stripe to face the submount while preventing solder from reaching the stripe. This segmentation resolves the contradiction by creating distinct functional zones.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The trench acts as an intermediary barrier between the solder/bonding material and the laser active stripe. It mediates the interaction by allowing the stripe to be in a facing relationship with the submount for optimal optical coupling while simultaneously preventing direct contact that would cause mechanical and thermal stresses.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If the laser active stripe is placed in a facing relationship with the submount, then optical coupling is improved, but mechanical and thermal stresses increase due to direct contact with solder

Engineering Contradiction:

Improveoptical couplingVSAvoidmechanical and thermal stresses

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The submount surface is segmented into a bonding surface and a facing surface separated by a trench. The trench divides the space between electrical contacts, allowing the laser active stripe to face the submount while preventing solder from reaching the stripe. This segmentation resolves the contradiction by creating distinct functional zones.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The trench acts as an intermediary barrier between the solder/bonding material and the laser active stripe. It mediates the interaction by allowing the stripe to be in a facing relationship with the submount for optimal optical coupling while simultaneously preventing direct contact that would cause mechanical and thermal stresses.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If solder directly contacts the laser active stripe, then bonding is simplified, but electrical shorts and mechanical damage occur

Engineering Contradiction:

Improvebonding processVSAvoidelectrical short prevention

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The submount surface is segmented into a bonding surface and a facing surface separated by a trench. The trench divides the space between electrical contacts, allowing the laser active stripe to face the submount while preventing solder from reaching the stripe. This segmentation resolves the contradiction by creating distinct functional zones.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The trench acts as an intermediary barrier between the solder/bonding material and the laser active stripe. It mediates the interaction by allowing the stripe to be in a facing relationship with the submount for optimal optical coupling while simultaneously preventing direct contact that would cause mechanical and thermal stresses.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP3583667B1Bonded laser with solder-free laser active stripe in facing relationship with submount

Publication Date: 2023.07.12 CISCO TECHNOLOGY INC

Figure 1A~1B
Figure 1C~1D
Figure 2A

AI summary

A laser light source, a submount for a semiconductor laser, and a method of providing a laser light source are provided. The laser light source includes a submount with first and second electrical contacts thereon and a trench therebetween. A semiconductor laser is bonded to the submount by bonding third and fourth electrical contacts of the laser to the first and second electrical contacts, respectively. The third and fourth electrical contacts of the laser are arranged on opposite side of a laser active stripe, which is arranged over the trench of the submount.