PCB assembly involves mounting electronic components securely on a printed circuit board (PCB). It utilizes two main technologies: Surface-Mount Technology (SMT), where components are placed directly on the PCB surface, and Through-Hole Technology (THT), involving components inserted through holes and soldered. Quality control steps such as visual inspection, electrical testing, AOI, and X-ray inspection ensure high-quality assembly. The BOM list specifies materials needed for PCB assembly, critical for accurate production and meeting specifications.