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PCB Plating-An Important Part


PCB plating is an important part of manufacturing printed circuit boards. All copper traces that are found on the PCB should be plated. Otherwise, the copper may oxidize and cause deterioration. Finally, the PCB can be unusable without plating.


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1.PCB Plating Trace

2.Hot Air Solder Leveling (HASL)

3.Immersion Tin

4.Organic Solderability Preservative (OSP)

5.Electroless Nickel Immersion Gold (ENIG)


There are several methods and materials that are used in PCB plating:


1.PCB Trace Plating

The external traces that are found on the PCB have to be protected because copper that is unprotected ends up being oxidized which makes them deteriorate and the end of it all this circuit board will be unusable. One is able to identify a corroded copper from its color which is going to be green. Copper plating which is also commonly referred to as copper finish, surface finish, and the copper coating has two major importance which is; protecting the copper circuitry that is exposed and for providing a surface that is solderable when assembling the components on the PCB. There are different options for plating where each has its disadvantages and advantages.


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2.Hot Air Solder Leveling (HASL)

It is known as a tried and true method of copper plating. It is done by dipping the board in the solder that is molten then you level it using the hot air knife. HASL is considered to be the least expensive method of PCB finishing for the surface. It is available widely and it is very economical. One of the advantages of using HASL is that one can easily rework on the copper finish hence giving a long shelf life for the copper finish and also it serves as an option that is ideal for the through hole or the SMT components that are larger on the PCB.


3.Immersion Tin

This is a coating method that uses the process of a chemical to deposit a layer of flat metal directly on copper traces. Other than giving a surface that is flat for soldering, tin immersion doesn’t need the usage of lead hence this process is able to yield a PCB surface that is RoHS-compliant.


4.Organic Solderability Preservative (OSP)

This process helps in protecting the surface of the copper from oxidation. This is applied by the absorption of chemical on the surface of copper. This is an eco-friendly and cheap process.


5.Electroless Nickel Immersion Gold (ENIG)

This is a PCB plating method where a thin gold coating is layered over a coating of Nickel which is thin. This nickel will be the barrier to copper and this is actually the surface where components are soldered and the gold, in this case, is used to protect nickel when it is stored. This might be quite an expensive process.



PCB plating is essential in order to ensure that the copper is protected from oxidation. There are different PCB plating methods. You just need to choose according to your requirements.


Hi, I am Hommer, the founder of WellPCB. So far we have more than 4,000 customers worldwide. Any questions you can feel free to contact me. Thanks in advance.