PTH (Plating Through Hole) metallizes the hole, so the layer connected to it is conductive; there is an electrical connection. In contrast, NPTH (Non Plating Through Hole) is a non-metallized hole, which means that there is no copper on the inside of the hole; electrical isolation.

Difference between pth and npth holes

NPTH is Non PLATING Through Hole, the hole wall has no copper, generally it is a positioning hole and a gong wire hole. It can be sealed with dry film or plugged with rubber particles before electroplating or drilled or tapped twice after electroplating.

In the design of the pcb board, the hole has four functions: electrical conduction, positioning, heat dissipation, and convenient sub-board. The holes are divided into through holes (PTH) and non-conductive holes (NPTH). In general design, only PTH holes have hole rings, and NPTH holes do not have hole rings, but some special cases will also The NPTH hole is designed with an annular ring (the annular ring at this time plays a grounding role).