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1693 RLC Digibridge
3.2.7 7000-05 Tweezers
The 7000-05 tweezers combine the two functions:
• They handle chip components, up to 0.5 in.
(12 mm) thick.
• Serve as a test fixture for measuring these com-
ponents, if their terminals are on opposite faces.
The 7000-05 Chip Component Tweezers can handle
small unleaded "chips" or SMDs (surface mounted
devices), passive sensors, and components for test-
ing on the Digibridge. A four-terminal Kelvin con-
nection extends to the tip of the tweezers where the
measurement becomes two-terminal, therefore series
impedance of the connecting cables and internal
tweezer connections do not affect the measurement.
The small amounts of residual-tip resistance and
inductance can be automatically corrected by using
the Digibridge shorting function with the tips pressed
together. Guard shields between the tweezer blades
minimize capacitance between them. A correction for
this small capacitance can be made using Digibridge
open circuit test with the tips held at a spacing equal
to that of the component's contact spacing.
Figure 3-13: 7000-05 Chip Component
Tweezers
22
For this accessory an additional accuracy (for param-
eters listed) must be added to the standard instrument
accuracy as defined by AutoAcc.
C: ± 1.5 pF
R: ± 10 mΩ
Q: for R > 100 Ω, ±(9 * Freq * R * 10
Q; for R ≤ 100 Ω, ±((R/Freq) * 10
Measurement accuracy is very sensitive to connection
geometry. The same connection geometry must be
used for open/short compensation as for connection
to the device under test.
Connection to Digibridge:
Connect to
Cable Marking
Digibridge
PH (potential, high)
HS
IH (current, high)
HD/HF
PL (potential, low)
LS
IL (current, low)
LD/LF
The PH (HS) and IH (HD/HF) cables connect to the
fixed arm of the tweezers (+) and the PL (LS) and
IL (LD/LF) cables connect to the movable arm of
the tweezers (-). To ensure valid measurements it is
especially important to observe the correct polarity
when DC bias is to be used.
If dc bias is used (see paragraph 3.7), note that the
fixed arm of the tweezers is positive and the movable
arm is negative.
L: ± 100 nH
ppm)
-12
ppm)
-6
Connection to DUT
to positive (+) terminal
of DUT
to negative (-) terminal
of DUT
Operation
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