Wafer-Level Micro-Lens Array Coupling for Photonics Die Alignment
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Solution Overview
Problem
Existing semiconductor packaging technologies face challenges in achieving highly accurate alignments between silicon optical waveguides and external optical waveguides, requiring stringent alignment accuracy and robust interfaces to withstand operational stresses without degrading optical performance.
Innovation Solution
The integration of a micro-lens array optically coupled with a photonics die at the wafer level, which reduces alignment accuracy requirements by collimating light beams to a larger diameter, facilitating lower-cost, high-volume manufacturing processes and improving package yield through less stringent process control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional direct coupling methods are used between optical fibers and photonics die, then alignment accuracy of ~1-2 um is required, but manufacturing cost and complexity increase significantly
Solution Approach 1:
A micro-lens array is introduced as an intermediary component between the optical fibers and the photonics die. The lens array collimates the light from the fibers, creating a larger effective beam diameter that reduces the alignment precision requirement from ~1-2 um to ~10 um, thereby simplifying the packaging process while maintaining optical performance
Solution Approach 2:
The invention changes the optical parameter of the light beam by using the micro-lens array to collimate the divergent light from the fibers. This transforms the beam into a parallel or near-parallel configuration with a larger effective diameter, which directly reduces the required alignment precision and enables lower-cost manufacturing
2Reliability
If stringent alignment accuracy is maintained to ensure optical performance, then manufacturing yield decreases due to higher process control requirements
Solution Approach 1:
The micro-lens array acts as a mediator that decouples the optical performance requirement from the alignment precision requirement. By collimating the light, it ensures that even with relaxed alignment tolerances (~10 um instead of ~1-2 um), the optical performance remains acceptable, thereby increasing manufacturing yield
Solution Approach 2:
The lens array changes the beam parameters (increasing effective diameter and reducing divergence), which allows the system to maintain optical performance with significantly relaxed alignment tolerances. This parameter transformation enables higher manufacturing yield by reducing the impact of normal process variations
3Manufacturing precision
If advanced alignment techniques are used to achieve high precision, then manufacturing cost increases due to expensive tooling and slower processes
Solution Approach 1:
The micro-lens array is a simple, inexpensive intermediary component that enables the use of standard, low-cost manufacturing processes. By providing optical collimation, it eliminates the need for expensive specialized tooling and complex alignment equipment, thereby reducing manufacturing cost while maintaining acceptable precision
Solution Approach 2:
The lens array changes the optical parameters to allow the use of conventional manufacturing processes with standard tolerances. This parameter transformation makes the process more manufacturable using existing tooling and procedures, significantly reducing equipment costs and manufacturing complexity
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 approach enhances manufacturing efficiency and yield by relaxing alignment accuracy from ~1-2 um to ~10 um, allowing for less expensive tooling and faster processes while maintaining optical performance.
Implementation Method 1
The integration of a micro-lens array optically coupled with a photonics die at the wafer level, which reduces alignment accuracy requirements by collimating light beams to a larger diameter
Data Source
AI summary
Embodiments described herein may be related to apparatuses, processes, and techniques for coupling a micro-lens array to a photonics die. In embodiments, this coupling may be performed as an attach at a wafer level. In embodiments, wafer level optical testing of the photonics die with the attached micro-lens array may be tested electrically and optically before the photonics die is assembled into a package, in various configurations. Other embodiments may be described and/or claimed.