Page 35 - Chip Scale Review_November-December_2023-digital

T h e f i n al o p t i m i z e d r e s u l t s
we r e a ch ieve d by r e pla ci ng t he
ground probes with probes of larger
dimensions than the signal probe
(inversion probe placement) and
changing the probe orientation inside
the probe head. A large ground probe
enables the same retur n loss and
insertion loss improvement without
decreasing cross-talk performance.
In addition, the rotation of the probe
placement by 45°, as shown in Figure
6, will further improve the cross-
talk performance of the setup so that Figure 5: Probe array with enlarged probes: a) (left) Enlarged placement of non-rotated probes; and b) (right)
it approximates the performance of a Probe placement positions.
Faraday cage.
High-end probe card features.
The new concept of using cross-
section optimization and a Faraday
cage must be integrated with all other
technologies needed by high-end
probe cards to achieve all the features
required by a high-end device. A
collaboration effort with Technoprobe
was established to develop a product
line of hybrid probe solutions called
Merlion. This new probe solution
featured the Technoprobe patented
HiP architecture whereby additional Figure 6: Probe cross-section physical constraints: a) (left) Inversion probe placement of rotated probes; and
b) (right) Probe placement positions.
features are inserted in the probe
head with the aim of distributing the
current more evenly at power (PWR)
and ground (GND) levels (Figure
7). SA2 probe alloy was adopted as
the probe material. SA2 provided
high strength and high conductivity
coupled with low and stable contact
resistance. The extended lifetime
(XLT) probe head design is also
being integrated into the probe head Figure 7: Techoprobe HIP architecture.
desig n to extend the probe head
lifetime (Figure 8). The combination
of HIP and SA2 resulted in a high
cu r rent- ca r r y i ng capacit y probe
solution that was able to support
the coming challenges in probing
applications for HPC with a lower
cost of ownership when using the
XLT solution.
Probe head resonant optimization. Figure 8: Techoprobe XLT architecture.
The cross-section tuning and Faraday
cage concept have been applied to
different probe classes to evaluate
performance (i.e., the probe’s self-
r e s o n a nc e f r e q ue nc y i s l e n g t h
dependent and therefore, probe-class
Figure 9: External loopback channel model.

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