3 ms·

He probably means SMT - surface mount technology.

• dsr_ 8y ago
  SMT is the technology; individual devices are SMDs, or "surface-mounts" or "surface-mounted". Beyond terminology, SMD are much harder for an individual hobbyist to desolder, replace and resolder than through-mount, but they are easier for pick-and-place machines to deal with. If you're prototyping a simple device, you can start with a breadboard -- no soldering. Then you can get a circuit board printed to your spec and use the same components, for low-volume work. If you need high-precision placement, you will probably need to transition to surface-mount.
  • jonhendry18 8y ago
    "Beyond terminology, SMD are much harder for an individual hobbyist to desolder, replace and resolder than through-mount, but they are easier for pick-and-place machines to deal with." And SMD are smaller, allowing smaller circuit boards and smaller devices.