What is the role of holes on printed circuit boards (PCB)? What are PTH / NPTH holes? And what’s the difference between two of them?

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Accepted Answer

If you look closely at the printed circuit boards (PCB). You will see that there are many holes with different size on the boards. Those holes on PCB can be simply divided into two types: PTH (Plating Through Hole) and NPTH (Non Plating Through Hole).
The easiest way to distinguish between PTH (Plating Through Hole) and NPTH (Non Plating Through Hole) in PCB is to see if there are any traces of plating on the borehole wall in the PCB.
NPTH (Non Plating Through Hole) refers to a hole without copper in the borehole wall. It is generally used as the positioning hole and screw hole of PCB. The hole diameter is usually larger than PTH.
PTH (Plating Through Hole), the borehole wall has a layer of copper, the PTH holes on PCB has two purposes:
1. Used as component hole for welding DIP components, the hole diameter must be larger than the pin of the component, so that the component can be inserted in the PTH.
2. Another relatively small PTH (Plating Through Hole), also known as “Via”, can be used to connect and conduct wiring between different layers in PCB.