Document 6578387

Impedance Standard Substrate
(Pitch: 50 – 75 um, Configuration: Ground-Signal-Ground)
P/N: 138-356, S/N:
138-356
CASCADE MICROTECH
899-118
2006
Key to the 138-356 Map
Substrate specifications: Material: Alumina; Thickness: 10 mils (254 um); Dielectric constant: 9.9
Note: Ensure the
bias supply is turned
off during
calibration. Applying
bias to the probe
during calibration
could cause the
resistance of the load
to change.
Thru
Open
Load
Thru delay: 0.5 ps
Length: 135 um
DC accuracy:
+/- 0.3 %
Impedance: 50 Ohm
(Nominal)
Note: Thru and
Verification line
lengths are signal
conductor edge-toedge dimension.
Short
Precision
50 Ohm Load
Note: For optimum
calibration accuracy
only the Red marked load
standards should be
used.
Verification Lines
ID
ps
um
K1
0.5
135
K2
0.5
135
K3
0.5
135
K4
0.5
135
K5
1.1
215
K6
1.4
250
K7
1.9
315
K8
2.3
365
K9
2.7
420
K10
3.2
485
K11
3.8
570
K12
4.5
655
ID
L1
L2
L3
L4
L5
L6
ps
1
3
7
14
27
40
um
200
450
900
1800
3500
5250
65 um
Alignment Marks
Note: ISS must be
mounted on absorber
material (such as ISS
Holder PN 116-344)
during calibration.
All of the above specifications are based on an overtravel (downward movement of probe after initial touchdown on the substrate) of 2550 µm for Infinity style probes. This amount of overtravel can be set before calibration on the Impedance Standard Substrate (ISS) using
the alignment marks (allows precise setting of probe separation and overtravel). Figure 1 shows that initial contact with the edge of the
probe tips should be made at reference plane X. The desired overtravel and thus skate (forward movement of probe tips after initial
contact with substrate) is then achieved by adjusting the Z height on the positioner to move the edge of the probe tips to reference plane
Y. This can also be seen from the photographic images shown in Figure 2.
Initial contact
Figure 1: Alignment
marks
Final contact
Figure 2: Images showing correct alignment and placement of probe tips
of Infinity style probes.
Calibration Coefficients –Depending on the probe style, configuration and pitch, different levels of performance can be expected when
using this ISS. Please refer to the probe specifications for performance limits.
Infinity
Pitch
50
75
WG-GSG
C-open
L-short
Coaxial-GSG
L-term
Please refer to values shipped with your
probe
C-open
L-short
L-term
5.9
16.5
7.8
6.7
17.0
7.7
Note1: Units for C-Open = fF, L-Short = pH, L-Term = pH
Document PN: 138-369 rev A
Please see the Cascade Microtech web site for further information on this and other ISS: http://www.cmicro.com.
Cascade Microtech, Inc., 2430 NW 206th Ave, Beaverton OR 97006, USA
Tel: (503) 601-1122; Japan: +81 3 5478 6100; Europe: + 44 1295-812828; Singapore: +65 6873 7482
E-mail: [email protected]; Japan: [email protected]; Europe: [email protected]; Singapore: [email protected]