Design Guidelines for “w” Connectors
The ZEBRA® W series elastomeric connectors are highly accurate silicone rubber pads with fine metal wires embedded in the thickness direction. The wires are gold-plated, providing low resistance and relatively high current flow with anisotropic conduction properties.
Standard pitch patterns offer dense I/O’s at closely positioned centerlines. To specify the appropriate design layout for your application, the following simple steps are recommended:
1.Determine the pitch
2.Decide if interconnect is static or repeated compressions
3.Specify overall dimensions
1. DETERMINING IF THE APPLICATION IS STATIC OR REQUIRES REPEATED COMPRESSIONS
a.) Static interconnect between mating conductors use the WSL (1.0mm pitch) or WSC (0.35mm pitch) versions. The fine wire conductors protrude slightly from both top and bottom of the silicone rubber to ensure contact with conductors under just very slight pressure (about 10% compression).
b.) Repeated compression interconnects such as testing pads use the WBC (0.35mm pitch) version containing curved conductors with spring properties which allow the connector to recover to original height without compression set after repeated deformations.
2. DETERMINE PITCH REGISTRATION
a.) Pitches available: 1.0mm and 0.35mm for “W” series; and, 1.0mm, 0.8mm and 0.5mm for “P” series
b.) Select the pitch which assures that at least one conductor connects between the contact pads to be mated, and that at least one insulating area is between adjacent contact pads.
c.) If redundant contact is desired, select the pitch that assures at least two conductors connect between the contact pads to be mated and at least one insulating layer is between adjacent contact pads.
3. DETERMINE EXTERIOR DIMENSIONS
a.) Length – allow an additional 0.5mm beyond the edge of the conductor at each end of the row in the length direction. Maximum length is 40.0 mm
b.) Width – allow an additional 0.5mm beyond the edge of the conductors at each end of the row in the width direction. Maximum width is 20.0 mm
c.) Thickness – two thicknesses are available for each style of “W” connector: 0.5 and 1.0mm. Allow 10% compression of original height to achieve reliable contact. Consider using a compression stop spacer (see drawing) to control compressed height. More than 20% compression is not recommended.
REFERENCE – TYPICAL ENVIRONMENTAL TESTING CHARACTERISTICS
|Test||Method||Description||Live Current||No Current||No Current|
|MIL-202D-106c||Test cycle: -20?C’23?C’|
65?C’, 95% RH, 1 Test
cycle/day x 10 days
|–||No change||No change|
|Moisture||MIL-202D-103B||40?C @ 95% R.H.|
Continuous 1500 hours
|No change||No change||No change|
|MIL-202E-107D||Test cycle: -65?C’25?C’|
150?C’25?C, 5 cycles
|–||No change||No change|
|MIL-IEC-68-2-42||SO2 gas, 25PPM, 25?C|
75% RH, 21 days
|–||No change||0.20’0.35 Ω-mm2|
|MIL-202D-108A||120?C, 500 hours||–||No change||No change|