PTH and NPTH are terms used in printed circuit board (PCB) design, and they stand for “Plated Through-Hole” and “Non-Plated Through-Hole,” respectively.
A Plated Through-Hole (PTH) is a hole that has been drilled through the PCB and has had a thin layer of conductive material, such as copper, plated onto its walls to create a connection between the different layers of the board. This type of hole is used to create vias or to mount through-hole components on the board.
On the other hand, a Non-Plated Through-Hole (NPTH) is a hole that is drilled through the PCB but does not have any conductive plating on its walls. This type of hole is used to provide clearance for mechanical fasteners or to allow the insertion of non-electrical components, such as standoffs or mounting holes.
It’s important to note that PTH and NPTH holes have different specifications and requirements for their drilling and manufacturing processes. PCB designers need to carefully consider the placement and size of both types of holes to ensure that they meet the design specifications and manufacturing capabilities of the PCB fabrication process being used.