Abstract: The continuous advancement of technology has drawn increasing academic attention to research on advanced packaging technologies. Researchers are committed to developing innovative substrate fabrication processes to meet evolving market demands and technical challenges, with the primary goal of enhancing packaging performance, reliability, and cost-effectiveness to better support electronic product development and applications. This paper primarily discusses process improvements and fine-line fabrication, introducing the characteristics and processes of dry film technology while focusing on China’s emerging modified semi-additive process (MSAP) for substrate production, which represents a widely adopted technology in current substrate manufacturing.