The technique of electroplating involves plating different metals onto a metal or plastic component. This enhances the part's functioning while also improving its look. Electroplating is frequently used to coat cheaper metals or polymers with more costly or less corrosive metal layers. The part lasts longer because of the strength and corrosion resistance that plating gives it. Depending on the metal used, plating can also provide additional qualities like electrical conductivity and adhesive strength.
Physical vapour deposition (PVD), like electroplating, increases a part's strength and endurance while also giving it a beautiful aspect.
Because it refers to a series of coating manufacturing methods carried out in an artificial vacuum, PVD is unique. Since they don't produce chemical waste, PVD coatings are ecologically beneficial. PVD is a more lighter and minimal maintenance solution for you, in addition to being environmentally beneficial.
Figure 1 shows the working principle of two major PVD deposition techniques namely cathodic arc evaporation (CAE) and magnetron sputtering (MS). The vapor is created by physical mean, by electric arc in CAE, and with energetic particle bombardment in MS.
For a long time, the industrial industry has relied on electroplating techniques.
In today's fast-paced business environment, organisations must swiftly adapt to the ever-changing terrain brought forth by technological breakthroughs.
Several firms continue to utilise electroplating because it is the industry standard.
Physical Vapor Deposition (PVD) methods are better in many instances.
To electroplate something, it must be immersed in a tank of solution containing the desired deposit. The cathode, or negative pole, of the power source is attached to the object being plated.
The material to be deposited is attached to the power source's anode (positive pole). When a voltage is applied by the power source, the negatively charged substrate attracts the positively charged ions of the atoms to be coated. Below is a schematic representation of the principle of electroplating with the example of thick copper films on a seed layer deposited in a silicon or glass wafer. It is possible to deposit thick conductive metal films with a thickness higher than 5 µm.
Electroplating is a form of low-energy coating. Because this is a low-voltage electrochemical process, the ions' energy levels are low when they reach and deposit on the substrate.
Large edge buildups are unavoidable and impossible to avoid throughout this process. The shape of the component might also impact the consistency of the deposit. It's difficult to avoid a substantial accumulation around the edges of channels and crevices when electroplating.
What makes Physical Vapor Deposition (PVD) superior to electroplating?
In recent years, vacuum vapor deposition, or PVD coating, has progressed from a specialty method to a popular one. Due to its scalability, it can now handle large, complex part geometries effectively and affordably.
Some industries have profited from the transition from electroplating to PVD coating. Coatings Layers can be deposited at temperatures as low as room temperature and as high as 500 degrees Celsius, depending on the substrate and intended usage.
The PVD process offers a wider range of deposition materials, stronger adhesion (up to six times greater in some cases), and less toxic chemicals. PVD coatings are preferred over electroplating for a variety of applications due to fewer environmental and chemical disposal costs.
The product is held in place by a fixture while it is PVD coated, and then the entire assembly is moved to the vacuum chamber. The gadget is evacuated to the desired vacuum pressure level. Before the product is suitable for use, it must be preheated and sputtered, however these stages vary according to the substrate and production method.
If the substrate is conductive, a negative bias is applied after the sputter cleaning is finished, and the cathode material is charged negatively. Bipolar HiPIMS or microarcs are the best procedures if the substrate is non-conductive.
Figure 3 shows an example of voltage waveform of a bipolar HiPIMS as well as the current waveform at the target and substrate. It is also shown how the hardness is increased by a factor of 2 when the pulse duration of the positive pulse is increased.
