Silicon Optical Bench with Reflector Layer for Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-chip module packages using ceramic or organic polymer substrates often have insufficient coefficient of thermal expansion (CTE) matching and heat dissipation properties, leading to reliability issues for III-V semiconductor material-based optoelectronic chips and high power amplifiers.
Innovation Solution
An integrated optical bench on a silicon substrate is designed, featuring a trench with a reflector layer, dielectric layers, and a waveguide to facilitate better thermal matching and heat dissipation, using materials like SiN, SiO2, and metals for high reflectivity and conductivity, along with PECVD and spin-on processes for layer formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ceramic or organic polymer substrates are used in multi-chip module packages, then the substrate provides structural support and electrical insulation, but the coefficient of thermal expansion (CTE) matching to semiconductor chips is insufficient and heat dissipation property deteriorates
Solution Approach 1:
The patent changes the substrate material from ceramic or organic polymer to silicon, fundamentally altering the thermal and mechanical parameters. Silicon provides superior CTE matching to III-V semiconductor materials and enhanced heat dissipation capability, directly resolving the thermal expansion mismatch and heat accumulation problems
Solution Approach 2:
The patent employs a composite structure integrating silicon substrate with metal heat sinks and thermal interface materials. This composite approach combines the mechanical stability of silicon with the high thermal conductivity of metals, achieving both structural support and superior heat dissipation while maintaining CTE compatibility
2Reliability
If conventional substrate materials are used, then manufacturing is simpler, but reliability for III-V semiconductor optoelectronic chips deteriorates due to insufficient CTE matching
Solution Approach 1:
The patent changes the substrate material parameter from conventional ceramic or organic polymer to silicon, which has a CTE of approximately 2.6-3.5×10^-6/K, closely matching III-V semiconductor materials. This parameter change ensures thermal compatibility and prevents reliability issues during thermal cycling
3Adaptability or versatility
If more optical components are integrated on the substrate, then functionality increases, but crosstalk among optical channels increases
Solution Approach 1:
The patent divides the optical system into separate integrated optical circuits on the silicon substrate, with each optical channel independently routed. This segmentation prevents crosstalk by isolating optical paths while maintaining high integration density, allowing multiple optical components to function without interference
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
The solution provides improved thermal expansion matching and heat dissipation for optical components, enhancing reliability and data transfer rates while reducing crosstalk among optical channels, and enabling more robust and cost-efficient integration of optics using silicon micro-fabrication technology.
Implementation Method 1
a reflector layer over a sloping side of the substrate
Implementation Method 2
An integrated optical bench on a silicon substrate is designed, featuring a trench with a reflector layer, dielectric layers, and a waveguide to facilitate better thermal matching and heat dissipation
Implementation Method 3
along with PECVD and spin-on processes for layer formation
Implementation Method 4
along with PECVD and spin-on processes for layer formation
Data Source
AI summary
A method of forming an optical bench includes forming a reflector layer over a sloping side of a substrate. The method includes depositing a redistribution layer over the substrate. The method includes disposing an under bump metallization (UBM) layer over the redistribution layer. The method includes forming a passivation layer over the redistribution layer and surrounding sidewalls of the UBM layer. The method includes mounting a first optical component over an uppermost portion of the substrate, wherein the reflector layer is configured to reflect an electromagnetic wave from the first optical component, and the first optical component is mounted outside the trench.