SMD is the abbreviation of Surface Mounted Devices, which means: surface mount devices, including CHIP, SOP, SOJ, PLCC, LCCC,QFP, BGA, CSP, FC, MCM, etc
SMT is the surface mount technology (short for Surface Mount Technology) and is currently the most popular technology and process in the electronics assembly industry. Surface Mount Technology (SMT) is a new generation of electronic assembly technology that compresses traditional electronic components into devices that are only a fraction of a tens of volume, enabling high-density, high-reliability electronics assembly. Miniaturization, low cost, and automation of production. This miniaturized component is called: SMD device (or SMC, chip device). The process of assembling components onto a printed circuit board PCB is referred to as an SMT process. The associated assembly equipment is called an SMT equipment.