How do I handle ESD protection during assembly and test of sensitive RF components?

How do I handle ESD protection during assembly and test of sensitive RF components? ESD (Electrostatic Discharge) is one of the most common causes of latent and catastrophic failure in RF devices, particularly GaAs and GaN MMICs, which have thin gate oxides and small gate geometries that are highly vulnerable: (1) ESD sensitivity of RF devices: GaAs pHEMT: HBM (Human Body Model) rating = 200-500V (very sensitive). GaN HEMT: HBM = 500-2000V (moderate). LDMOS: HBM = 1000-4000V (more robust). SiGe BiCMOS: HBM = 500-2000V. CMOS RF: HBM = 250-1000V (gate oxide is most vulnerable). For reference, a person can generate 3,000-25,000V by walking across a carpet. Even 100V HBM can damage a GaAs device. (2) ESD-safe workstation requirements: grounded work surface (ESD-dissipative mat, surface resistance = 10^6 to 10^9 ohms). Wrist strap (resistance = 1 MΩ, connected to facility ground). Grounded soldering iron tip (verified daily). Ionizer (overhead ionizing blower to neutralize charge on insulators). Humidity control (maintain 40-60% RH; below 30% greatly increases static generation). ESD-safe packaging (pink poly bags for general handling, metallic shielding bags for transport). (3) Assembly procedures: always touch a grounded surface before handling bare die or packaged devices. Use vacuum wands with conductive tips for die handling (never metal tweezers). Solder RF connectors before installing sensitive devices. Power supplies must be set to the correct voltage before connecting to the DUT. Never connect or disconnect RF cables while bias is applied. (4) Test procedures: connect ground first, signal last. Disconnect signal first, ground last. Use DC blocks on VNA ports when testing active devices. Verify the test fixture is ESD-grounded before inserting the DUT. For rack-mounted test systems: ensure all instruments share a common ground.