#throughhole

Selective soldering involves attaching specific components to printed circuit boards (PCBs) and molded modules, a method particularly useful for items susceptible to heat damage from standard reflow ovens or wave soldering found in conventional surface-mount technology (SMT) or through-hole assembly techniques. Typically, this method is applied after an initial SMT oven reflow phase. The components targeted for selective soldering are often nestled among others already soldered via a surface-mount reflow method. This demands high precision in the selective soldering process to prevent damage to the surrounding elements.

Through Hole technology is a technique for building electronic circuits in which the pin-through-hole (PTH) components are embedded through gaps penetrated into printed circuit boards (PCBs). The closures, or leads, are then appended to pads on the opposite side with molten metal solder using wave soldering or reflow soldering equipment. This process is also called through hole assembly.

Through Hole technology supplanted early electronics assembly techniques, for example, point-to-point development. From the second era of PCs in the 1950s until the point when the surface-mount technology ended up prevalent in the late 1980s, each part on a typical PCB was a through hole component