Wedge-Shaped Fiber Array for Simultaneous Si-Photonic Testing
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Solution Overview
Problem
Existing silicon (Si)-photonic device testing methods face low throughput and a high risk of damage due to the large contact area of conventional fiber arrays, which block the touch-down of DC and RF probe tips and cannot perform optical, electrical, and RF tests simultaneously.
Innovation Solution
A wedge-shaped fiber array with a customized bottom base is formed to expose bond pads of Si-Photonic devices, allowing for simultaneous optical, DC, and RF mixed signal tests by polishing the sidewalls and top surface of the fiber array to specific angles matching the grating coupler and probing pad layout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional fiber array with large contact area is used, then the risk of damage during touch-down is reduced, but the DC and RF probe tips cannot touch down and simultaneous testing cannot be performed
Solution Approach 1:
The fiber array is segmented into a wedge-shaped configuration where the contact area is divided into multiple zones with different dimensions. The fiber array tapers from a larger base area to a smaller top area, creating distinct regions that can accommodate different probe types (DC and RF probes) while maintaining structural integrity and distributing contact forces to prevent damage.
2Reliability
If a single fiber is used for testing, then the risk of damage during touch-down is reduced, but the throughput is very low
Solution Approach 1:
The invention merges multiple functions into a single wedge-shaped fiber array structure. It combines optical testing capabilities through the fiber array with electrical (DC) and RF testing capabilities by exposing bond pads on the same substrate. This integration allows simultaneous multi-parameter testing, dramatically increasing throughput while maintaining low damage risk through controlled contact mechanics.
3Reliability
If a conventional fiber array is used, then the contact area is sufficient to prevent damage, but it blocks the touch-down of DC and RF probe tips
Solution Approach 1:
The wedge-shaped fiber array implements local quality by having different contact area characteristics at different locations. The base of the wedge provides a larger contact area for force distribution and protection, while the top portion tapers to a smaller area that allows probe tip access. This spatial variation in contact area properties enables both protection and accessibility simultaneously.
Data Source
AI summary
A method of forming a wedge-shaped fiber array and a bottom base according to a probing pad layout of a Si-Photonic device to enable optical, DC and RF mixed signal tests to be performed at the same time and the resulting device are provided. Embodiments include a bottom base; and a fiber array with sidewalls and a top surface having a first angle and a second angle, respectively, over the bottom base, wherein the fiber array is structured to expose bond pads of a Si-Photonic device during wafer level Si-Photonic testing.