1. High Temperature & Humidity Test primarily assesses PCBA's corrosion resistance and insulation performance in humid environments. Common standards include IPC-A-610 and IEC 60068-2-78, with typical test conditions of 85°C/85%RH for 500-1000 hours. Common failure modes include solder joint oxidation and insulation degradation, which can be mitigated by using conformal coatings and