This paper provides a detailed analysis of the essential stages of SMT (Surface Mount Technology) and THT (Through-Hole Technology), which are fundamental to the manufacturing of printed circuit boards (PCBs). SMT involves highly precise processes, such as solder paste application on the PCB, automated placement of miniature components, and reflow soldering, ensuring a high level of automation and efficiency. In contrast, THT employs techniques such as manual or mechanical insertion of pin-through-hole components and wave soldering, providing superior mechanical strength for critical applications. The paper outlines each step of these technologies, highlighting their advantages, challenges, and their role in assembling modern electronic devices. By combining these methods, manufacturers address increasingly complex technological demands, emphasizing the importance of accuracy and innovation in the electronics industry. The final products must comply with a series of rigorous tests, such as functional testing, automated optical inspection, or X-ray inspection, to ensure quality, proper operation and safety.