Semiconductor Package Receptacle Cavity for Optical Coupling
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Solution Overview
Problem
The size mismatch between silicon photonic waveguides and optical fibers leads to optical signal attenuation due to coupling inefficiencies, hindering production throughput and increasing costs in optical communication products.
Innovation Solution
A wafer-level semiconductor package structure with a receptacle and recess forming a cavity, where the receptacle has a wider width than the recess, allowing for improved optical signal coupling through collimation and beam direction alteration, enabling passive alignment and increased production efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If direct coupling between waveguide and optical fiber is used, then device complexity is reduced, but optical signal coupling efficiency deteriorates due to size mismatch
Solution Approach 1:
A receptacle structure is introduced as an intermediary component between the waveguide and optical fiber. The receptacle includes a cavity with a first width that is smaller than the waveguide width, creating a confined space that improves mode field matching. This intermediary structure mediates the size mismatch between the small waveguide (220nm×450nm) and large optical fiber (9 micron diameter), thereby improving coupling efficiency without significantly increasing overall device complexity
Solution Approach 2:
The cavity width parameter is specifically designed to be smaller than the waveguide width (first width < waveguide width). This parameter change creates a gradual transition zone that transforms the optical mode from the waveguide to a size more compatible with the optical fiber, improving coupling efficiency through controlled parameter transformation rather than direct coupling
2Reliability
If active alignment method is used to improve coupling efficiency, then optical signal coupling efficiency is improved, but production time increases
Solution Approach 1:
The receptacle is pre-formed with a specifically designed cavity structure during the semiconductor manufacturing process, before the actual coupling operation. This preliminary action establishes the geometric parameters (cavity width smaller than waveguide width) that enable passive alignment, eliminating the need for time-consuming active alignment procedures during production while maintaining high coupling efficiency
3Ease of manufacture
If conventional packaging method is used, then manufacturing process is simple, but production throughput is low
Solution Approach 1:
The receptacle formation process is merged with the existing semiconductor manufacturing process flow. The cavity structure is created using standard semiconductor fabrication techniques (etching, deposition) that are already part of the waveguide manufacturing process. This merging allows wafer-level processing where multiple devices can be manufactured simultaneously, dramatically increasing production throughput while maintaining ease of manufacture through existing process infrastructure
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
Enhances optical signal coupling efficiency, reduces production time and costs by allowing for wafer-level integration and passive alignment, thereby improving the throughput of photonic ICs.
Implementation Method 1
the cavity configured to confine and direct optical beams
Implementation Method 2
the cavity configured to confine and direct optical beams
Data Source
AI summary
A semiconductor module includes a photonic integrated circuit and a receptacle. The photonic integrated circuit includes a substrate, a waveguide disposed on the substrate, and a recess in the substrate and having a first width. The receptacle is bonded to a top surface of the substrate and aligning with the recess. The receptacle and the recess jointly form a cavity, and the receptacle has a second width greater than the first width. A method for manufacturing the semiconductor module is also disclosed.