Small Outline IC (also known as “SO”) was the natural progression from DIP in effort to reduce cost. Similarly to DIP, SO packages have leads arranged in two opposing rows but in much smaller features and spaces than DIP. SO packages usually come in lead counts of 8, 14, 16, 20, 24, and 28.

Advances in semiconductor fabrication making IC chips smaller and smaller requires features of lead frames shrinking proportionally.

Due to its miniaturizing nature, precision in lines and spaces of the lead frames is more stringent than those of DIP. Despite SO smaller features, in today’s lead frame manufacturing standard, making SO lead frames doesn’t have many technical challenges but rather economical ones. Most SO devices are of low cost components; cost effectiveness is the most important consideration. Producing SO lead frames in massive quantity with high efficiency and with minimum yield loss is the key to cost effectiveness. SO is among the highest quantities produced among all the IC packages.