Aerospace Defense Semiconductor is military-grade semiconductor components for aircraft, missiles, defense systems meeting strict specifications for reliability, radiation resistance, temperature operation — highest-reliability requirements. Aerospace Standards DO-254 (hardware design assurance), MIL-STD standards (reliability). Altitude Environment temperature ranges from −55 to +125°C. Pressure varies. Radiation higher altitude: increased cosmic ray exposure. Vibration aircraft/launch vehicle vibration severe. Shakers test to specifications. Mechanical Shock ejection, crash landing, deployment shock. Electromagnetic military EMI environment hostile. Shielding, filtering required. Screening Tests 100% parts screened (burn-in, electrical testing). Sample destructive testing. Procurement military procurement through qualified vendors. Traceability documented. Parts Selection commercial-off-the-shelf (COTS) increasingly used with screening. Cost vs. custom design. Obsolescence parts become obsolete (manufacturer discontinues). Mitigation: procurement strategies, alternative part qualification. Space Applications satellites, space probes. Higher reliability (cannot service). Lower failure rates acceptable if redundancy provided. Hermetic Packaging ceramic or metallic packages. Enhanced protection vs. plastic. Potting conformal coatings, potting compound protect from humidity. Burn-In accelerated aging identifies early failures. Typically 160°C, 48-500 hours. Long-Term Storage military parts stored many years. Moisture barrier packaging (desiccant). Aging long-term drift in parameters. Tested and documented. Process Technology mature nodes preferred (90 nm−180 nm). Newer advanced nodes qualification underway. Qualification lengthy: characterization, testing, approval months to years. Design Review formal design reviews (preliminary, critical). Documentation comprehensive. Redundancy critical functions often triple-redundant. Voting logic. Hardened Logic gate hardening against radiation. Guard rings, enclosed structures. Testability built-in self-test (BIST) enables in-flight diagnostics. Traceability serial numbers, batch records maintained. Aerospace semiconductors enable critical defense systems with highest reliability.