Pintakytkentätekniikka

Pintakytkentätekniikka, often translated as surface-mount technology (SMT), is a method in which the electrical components are mounted directly onto the surface of a printed circuit board (PCB). This contrasts with through-hole technology (THT), where component leads are inserted into holes drilled through the board and soldered on the opposite side. SMT components are typically smaller and have no or very short leads, instead utilizing metal pads or balls that are soldered to the board.

The development of SMT began in the 1960s but gained widespread commercial adoption in the late 1980s and early 1990s. Key advantages of SMT include miniaturization of electronic devices, increased component density on the PCB, and improved performance due to shorter signal paths. It also facilitates automated manufacturing processes, leading to higher production speeds and lower costs. Common SMT components include resistors, capacitors, transistors, and integrated circuits, available in various package types such as SOICs, QFPs, BGAs, and chip-scale packages.

The SMT assembly process typically involves applying solder paste to the PCB pads using a stencil, placing components onto the paste using pick-and-place machines, and then reflowing the solder in an oven to create permanent electrical and mechanical connections. Wave soldering is generally not used for SMT due to the risk of components detaching. While SMT dominates modern electronics manufacturing, THT is still used for certain applications, such as components requiring higher mechanical strength or those with specific thermal management needs.