Surface-mount technology (SMT) is a manufacturing process used to assemble electronic components onto printed circuit boards (PCBs). Instead of inserting components through holes in the board, SMT places them directly on the board's surface using robotic pick-and-place machines. The components are then soldered in place using heat, creating a permanent electrical connection.
This technique emerged in the 1980s and has become the standard for mass-producing modern electronics. It allows manufacturers to pack components much more densely than older through-hole methods, resulting in smaller, lighter devices. Because SMT components are typically smaller than their through-hole equivalents, they also cost less to produce at scale.
Real-world impact: nearly every smartphone, tablet, laptop, and modern TV relies on SMT. A typical mobile phone processor or graphics chip contains billions of transistors that would be impossible to connect using older assembly methods.
When buying consumer electronics, you won't see SMT mentioned in product specs, but you'll notice its effects. Thinner phones, compact wireless earbuds, and portable gaming devices all depend on SMT assembly to fit powerful technology into tight spaces. The quality of SMT work also influences long-term reliability, though defects are rare in products from established manufacturers.