By Robert Stanton, Director Technology Omnetics Connector Corp.
Tough connectors ensure reliability in harsh environments.
Today’s electronic systems are evolving to ever- portable, present, continuous operation devices that
work in nearly every kind of environment. They’re often
lightweight, miniaturized versions of older electronics
that must work harder, run faster, and be immune to
outside effects like solar and electromagnetic fields.
They must also perform well during high physical
shock, vibration, and temperature extremes. Lead
designs, in this evolution, have included applications in
military instruments, portable soldier electronics, space
technology, unmanned vehicles, robotics, and down-hole
drilling in the petroleum industry. NASA and satellite
ruggedness requirements include unique specifications
from radiation protection to preventing outgassing of
polymers used to construct the device itself. Ruggedized
systems are also being applied in surveillance systems,
factory equipment, and remote surgical systems.
Oftentimes, the most exposed and vulnerable portions
of electronic systems are the extended cables, connectors,
and interconnections used to route signals and power
from one portion of the system to another. Ensuring
product reliability requires a combined focus on material
selection, physical design, and electrical processing
capabilities. To ensure new designs survive and perform to
expectations, a range of specifications and guidelines are
established early in the process of development.
The breadth and depth of new designs requires the
designer to consider specifications and level that his
equipment may need to be designed to meet. Micro-
connector and cable system designs, for example, are
often guided toward high-reliability performance using
MIL-DTL- 83513. Nano-sized interconnect systems
are tested to the specified MIL-DTL-32139. These
specifications define numerous levels of testing that assure
continuous performance through shock and vibration,
temperature cycling, even the number of contact mating
and un-mating cycles they must pass. To achieve these
rugged specifications, the smaller connectors must use
specially designed pin and socket interface methods that
remain intact during their use. Often, specially tempered
Beryllium-Copper (BeCu) spring pins are designed and
plated with layers of nickel, then over-plated with gold
to ensure performance. One noteworthy advantage of
designing micro- and nano-sized electronics is their lower
mass helps circuits withstand higher shock and vibration
during increased velocity.
Additional benefits of designing ruggedized miniature
interconnects is that they lend to expanding their use in
1. Automotive Sensor and Detector Systems
Automotive sensor and detector systems contain highly
portable electronics used to predict and protect collisions
and/or offer design improvements in the auto interior to
protect passengers. Crash test dummies are designed with
multiple electronic capabilities including measuring and
direction of impact, even relax-mode after the impact.
The sensor systems are extremely small, lightweight, and
ruggedized to withstand multiple tests.
2. Ground Troop Electronics
Ground troop electronics will often require reliable devices
like highly flexible cabling and connectors that will be
exposed to water splash, immersion, along with intense
exposure to solar radiation and heat. They must also be
rugged enough to handle travel through rough terrain, along
with being quickly plugged and unplugged through many
cycles. Cable materials like polyurethane jacketing with over-molded connectors that tightly seal and don’t deteriorate,
are mandatory to meet specifications like IP-67/68.
Figure 1: Black Diamond solider computer.