surface mount - Computer Definition
A circuit board packaging technique in which the leads (pins) on the chips and components are soldered on top of the board. Boards can be made faster because surface mount technology (SMT) eliminates drilling holes for thru-hole devices, in which the pins go through the board and are soldered underneath. Surface mount also allows the real estate under the device to be used for other layers by the board designer. In addition, the boards can be smaller because the chips are smaller; for example, SMT packages such as BGA have no leads extending out from the sides (see BGA). Contrast with socket mount and thru-hole.