Page 38 - Chip Scale Review_November-December_2023-digital

effect of needles during the measuring process. The
measurement results show a high impedance due to
the measurement setup itself. The microprobe setup
used a dual-pin probe (ground-signal), however,
only the nearest ground was contacted by the probe
ground pins, therefore, the return current flow is
only through the probe ground pins. This situation
causes a higher inductance compared to both
the direct measurement data and the stimulation
data. High inductance causes signal bandwidth
degradation, so the measurement results suffer a
degradation in quality. Therefore, a direct probing
measurement set up is not recommended.

Summary
The Merlion 6 hybrid probe solution has been
demonstrated to have the capability to meet all the
performance requirements of a high-end probe card
for HPC test applications. This probe technology—
in use since 2022—has met the high-speed test
requirements during wafer sort at AMD.
The probe solution also provides low and stable
CRES with high strength and conductivity. From
the simulation and TDR measurement correlation
data, we were able to show good agreement in
predicting the probe head impedance prof ile.
Additionally, the de-embedded S-parameters
measurement shows good IL) and RL correlation
with the simulation results.
This paper summarized the various aspects of
probe characterization for a high-speed performance
probe solution, and coupled with the high-power
PH (HiP) architecture, we were able to show a
minimal probe burnout while maximizing MTBF
in production.
As HPC workloads drive demand, the future will
Figure 14: Test fixture DIFF TDR simulation vs. measurement. have more stringent test requirements in terms of
higher speed and higher current-carrying capacity.
The design methodology from this paper will
form the baseline to meet the ever-increasing test
requirements that will catapult the industry to a
new way of designing for advanced applications.

Acknowledgements
The authors express their gratitude to Raffaele
Vallauri and Ivan Giudiceandrea from Technoprobe,
as well as to John Yi and Ng Hui Ying from AMD, for
their valuable contributions to this paper.

References
1. P recedence Resea rch: Hig h Per for ma nce
Computing Market (By Deployment: Cloud, On-
Premise; By Application: High Performance
Tech nical Computi ng, High Per for mance
B u s i ne s s C o m p u t i n g ; B y C o m p o ne n t s :
Solutions, Services; By Server Price Band; By
Figure 15: RF microprobe measurement results compared with simulation results.

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