Global Soul Limited (GS-SMT LTD), founded in 2011 and located in Shenzhen, China, is a global electronics specialist providing innovative solutions for Surface Mount Technology (SMT). One of the pivotal technologies in SMT is the SPI SMT machine, which plays a critical role in ensuring the quality of printed circuit board (PCB) assembly. This article delves into how SPI (Solder Paste Inspection) machines work, their benefits, applications, and the future of PCB assembly with a focus on the role of SPI SMT machine manufacturers.