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Mouser Electronics White Paper • Corrosion resistance: Many of the environments in which connectors are deployed can damage the connectors themselves. They must be designed to endure these conditions while maintaining performance. Reliability While ruggedness relates to performance conditions, reliability for an A&D design provides a measure of how a connector is expected to perform over time. Manufacturers and standards organizations can quantify a connector's ability to resist wear, oxidation, and fatigue. This ability allows the connector to maintain low electrical resistance and stable signal integrity even after years of service. One of the key metrics of any connector is the mating cycle. A single mating cycle represents one complete operation, comprising the act of mating and then unmating the connector. Most manufacturers test their connectors and publish the expected number of mating cycles that they can withstand. Standards such as MIL-STD-1344 and AS9100 provide the essential details for creating reliability metrics, including corrosion exposure and life cycle testing. Identifying Standards Deciphering standards is complicated, and the A&D arena includes a wide range of potential applications that often must comply with military specifications (MIL-SPEC) standards and US National Aeronautics and Space Administration (NASA) standards. Table 1 presents typical environmental hazards, possible applications, and relevant standards. Contacts Are the Key At the heart of every connector is the contact, which is the physical interface that must deliver low-resistance electrical conductivity, even when subjected to stress. More than any other component, the contact and how it interfaces with its mating counterpart determine a connector's performance and longevity. Achieving connector ruggedness and reliability is largely dependent on the geometry, materials, and plating of contacts. Contact Geometry, Material Selection, and Plating Contacts work in pairs. The geometry of an electrical contact refers to its shape and how it mates with its counterpart. This interface is critical for both electrical continuity and mechanical stability (Figure 2). Table 1: Environmental hazards, typical aerospace and defense applications, and the relevant MIL-SPEC and NASA standards used to qualify connector performance. Environmental Hazard Applications Standards Vibration resistance Defense vehicles, aircraft, and helicopters MIL-STD-202, MIL-STD-810 Shock resistance Projectile launches, artillery, and emergency landings MIL-STD-202, MIL-STD-810, MIL- STD-883, NASA-STD-7003 Temperature extremes Ground-based platforms, satellites, and space systems MIL-STD-202, MIL-STD-810, NASA- STD-5019, ECSS-S-ST-10-03C Sealing and ingress protection Tactical vehicles, front-line equipment, and soldier systems (i.e., wearable technology) MIL-DTL-53513 Corrosion resistance Marine and desert environments, resistance to automotive fluids MIL-STD-202 Figure 2: Proper contact force maintains pressure and stability. (Source: Molex)

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