PIC-SIP Integration via Cavity Substrate Alignment

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Solution Overview

Problem

The integration of photonic integrated circuits (PICs) and silicon photonics (SIPs) on a common substrate faces challenges in achieving precise alignment and thermal isolation due to manufacturing tolerances and thermal conductivity issues, hindering effective optical power transfer and wavelength control.

Innovation Solution

A common substrate with a cavity is used to mount PIC and SIP components, enabling hermetically sealed optical coupling and thermal isolation, allowing for precise alignment and mechanical decoupling of optical devices, thereby facilitating efficient optical communication and wavelength management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If PIC and SIP components are integrated on a common substrate, then device functionality and optical power transfer are improved, but manufacturing precision and alignment difficulty worsen due to tolerance accumulation

Engineering Contradiction:
Improvedevice functionalityVSAvoidalignment precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent introduces alignment marks and mechanical fixtures as intermediary elements that mediate between the PIC and SIP components during assembly. These intermediaries provide reference points and physical constraints that enable precise alignment despite manufacturing tolerances in the individual components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs preliminary alignment actions through pre-formed alignment marks and mechanical features on the substrate before final component assembly. This preliminary positioning establishes reference frameworks that guide subsequent assembly steps, ensuring precise final alignment.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If PIC and SIP components are placed in close proximity on the substrate, then device integration is improved, but thermal isolation deteriorates due to thermal conductivity

Engineering Contradiction:
Improvedevice integrationVSAvoidthermal isolation
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent segments the thermal management function by introducing thermal isolation structures that physically divide the thermal pathways between PIC and SIP components. This segmentation allows close spatial proximity for optical coupling while maintaining thermal independence through interrupted heat conduction paths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces thermal isolation structures as intermediary elements between the PIC and SIP components. These intermediaries act as thermal barriers that prevent direct heat transfer while allowing the components to remain in close proximity for optical functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If optical devices are mechanically coupled for stability, then structural strength is improved, but alignment precision worsens due to mechanical stress and deformation

Engineering Contradiction:
Improvestructural stabilityVSAvoidalignment precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent extracts the alignment function from the mechanical coupling structure itself by introducing separate alignment marks and reference features. This separation allows the mechanical coupling to provide structural strength while the dedicated alignment features maintain alignment precision independent of mechanical stress.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent establishes alignment through pre-formed marks and features before applying mechanical coupling. This preliminary alignment action locks in the precise positioning before structural elements are fully assembled, preventing subsequent stress-induced misalignment.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3035096B1Photonic integrated circuit (PIC) and silicon photonics (SIP) circuitry device
Publication Date: 2022.07.06 INFINERA CORP
  • EP3035096B1 patent drawingFigure 1
  • EP3035096B1 patent drawingFigure 2
  • EP3035096B1 patent drawingFigure 3

AI summary

A device may include a first substrate. The device may include an optical source. The optical source may generate light when a voltage or current is applied to the optical source. The optical source may be being provided on a first region of the first substrate. The device may include a second substrate. A second region of the second substrate may form a cavity with the first region of the first substrate. The optical source may extend into the cavity. The device may include an optical interconnect. The optical interconnect may be provided on or in the second substrate and outside the cavity. The optical interconnect may be configured to receive the light from the optical source.