Keywords:  pcb, solder, leadless, smt, smd
Board assemblies using leaded and leadless electronic components.
A technique for populating hybrids, multichip modules, and circuit boards, in which packaged components are mounted directly onto the surface of the substrate. A layer of solder paste is screen printed onto the pads and the components are attached by pushing their leads into the paste. When all of the components have been attached, the solder paste is melted using either reflow soldering or vapor-phase soldering.
A state-of-the-art construction method for electronic printed circuit boards (PCBs). The electronic components are attached to the top and or bottom surfaces of the PCB. The leads of the components are soldered to pads and do not pass through the PCB as with the older 'through-hole' method. Used to increase the packing density of electronic components and therefore increase the reliability and performance while reducing the overall system size.