Through-hole technology , also spelled `` thru-hole '' , refers to the mounting scheme used for electronic components that involves the use of leads on the components that are inserted into holes drilled in printed circuit boards ( PCB ) and soldered to pads on the opposite side either by manual assembly ( hand placement ) or by the use of automated insertion mount machines .
Through-hole technology is a way to mount electronic components to printed circuit boards ( PCB ) . It involves the use of leads on the components that are inserted into holes drilled in the PCBs and soldered to pads on the opposite side either by manual assembly ( handiwork ) or by the use of automated insertion mount machines .