In recent days PCB Assembly have been growing more and more complex and integrating into people’s lives more every day, but despite major advances in performance each year there are still only two common ways that electrical components are soldered together to make circuits: Surface Mount Technology (SMT) and Plated Through-Hole (PTH). Both SMT and PTH describe ways that electrical components, such as capacitors, resistors, and microchips are soldered to a Printed Circuit Board, or PCB as they are commonly referred to. This article will try to explain the type of PTH?
Through-hole technology, also spelled “thru-hole” are holes that go completely through the boards. They can be plated (PTH) or non-plated (NPTH)
So what are the difference between PTH and NPTH in PCB Assembly?
PLATED TROUGH HOLES (PTH)
In PCB Assembly, the most obvious feature of this type of hole is that a thin copper layer will be plated walls of the holes, enable conductivity between layers. This way, after the PCB Assembly is finished, the link between the component’s leads and the copper tracks has a lower resistance and better mechanical stability.
Plated Through holes are widely used in today’s PCB Assembly, such as double-sided, or multi-layered PCB Assembly, this way the components can connect to the required layers in the board. The mounting scheme of a PTH can be seen below figure.
NON-PLATED TROUGH HOLES (NPTH)
Likes its name says, there is no copper plated onto the walls of this type of Through Holes, so the barrel of the hole has no electrical properties. Such types of PTH are commonly used in single-layer boards or such boards have copper tracks printed on one side, but their usage will be decreased as the number of layers in PCB Assembly increased.
The main advantages of NPTH are that the manufacturing process for these is simpler and obviously quicker. Nowadays, they are frequently, but not exclusively, used as Tooling/Mounting holes: used to fix the PCB to its operational location. However, they can also be used for component mounting as shown below in Figure.