PCBA reliability testing subjects assemblies to environmental and mechanical stresses to predict lifespan and failure modes. Thermal cycling (-40°C to 125°C, 1,000 cycles) identifies solder joint cracks in automotive IGBTs, where temperature swings cause CTE mismatch between PCB (17ppm/°C) and components (6ppm/°C). Vibration testing (5–2,000Hz, 20G) simulates transportation stresses, critical for industrial controllers. HALT (Highly Accelerated Life Test) combines thermal, vibration, and voltage stress to uncover latent defects in 72 hours vs. 6 months of field testing.

For moisture sensitivity, MSL (Moisture Sensitivity Level) testing exposes PCBAs to 85°C/85%RH for 168 hours, followed by reflow soldering. Components must withstand popcorning (delamination) at 260°C peak temperatures. Electrochemical migration testing applies 5V bias in 85°C/85%RH conditions to detect dendritic growth between traces, a common failure in IoT devices.

Reliability metrics like MTBF (Mean Time Between Failures) are derived from accelerated life tests. For example, a 10-year MTBF is validated by operating 100 samples at 60°C for 10,000 hours. Compliance with standards like IPC-9701 (thermal cycling) and MIL-STD-810G (military-grade durability) ensures robustness. Emerging techniques include X-ray laminography for non-destructive BGA inspection and AI-based failure prediction using sensor data from field-deployed units.