SOP (Small Out-Line Package, small outline package) is a very common type of component. It is one of the surface mount packages, with leads extending from both sides of the package in a gull-wing (L-shaped) configuration. The materials used are plastic and ceramic. It originated in the late 1970s. Evolving from the through-hole insertion (PTH) type, with DIP (Dual In-Line Package) as the mainstream product before the 1980s, it advanced to SOP (Small Out-Line Package), SOJ (Small Out-Line J-Lead), and PLCC (Plastic Leaded Chip Carrier) derived from SMT (Surface Mount Technology) in the 1980s.
