Micro-Switch

Author: Postek Engineering Team | Reading time: 10 minutes Introduction Hermetically sealed micro switches are essential in aerospace, cryogenic, and high-reliability industrial systems — but they’re historically large. The trade-off was straightforward: hermetic sealing required thick metal walls, large glass-to-metal seals, and generous internal clearance for thermal expansion, all of which drove up envelope size. Designers working in space-constrained applications — compact actuators, dense flight systems bays, small orbital-platform mechanisms — were forced to choose between sealing and size. ...

Author: Postek Engineering Team | Reading time: 10 minutes Introduction “Sealed” is one of the most misused terms in component specification. Engineers frequently specify “IP67 rated” switches assuming they are protected against all environmental threats — only to discover that at 50,000 feet, their “sealed” switch has failed because the internal atmosphere equalized with near-vacuum external conditions. This article clarifies the fundamental differences between environmental sealing (IP ratings) and true hermetic sealing, and provides clear decision criteria for when each is appropriate. ...

Why Hermetic Sealing Matters In aerospace, mission-critical, and industrial applications, a switch is not just a switch — it is a potential point of failure. When a limit switch controls a orbital solar array deployment, a flight-critical arming sequence, or a cryogenic valve, the cost of failure is measured in mission loss, not warranty returns. Standard micro switches rely on plastic housings and elastomeric seals. Under thermal cycling, vacuum, radiation, or corrosive atmospheres, these organic materials degrade. The seal fails. Contaminants enter. The switch becomes unreliable — often without visible warning. ...

The UAV Switching Challenge Unmanned aerial systems present a unique combination of constraints for switching components: Extreme vibration from multi-rotor propulsion (10~2000 Hz spectrum) Weight sensitivity — every gram matters on smaller platforms All-weather operation — moisture, dust, and temperature extremes Regulatory requirements — flight termination systems must meet specific reliability standards No maintenance opportunity — switches must perform for the entire mission duration without inspection Standard commercial micro switches were designed for appliances and automotive interiors. They are not qualified for the vibration spectrum, altitude envelope, and reliability demands of UAV flight-critical circuits. ...