Physical Vapor Deposition
Physical vapor deposition (PVD) is a technique that is used to coat surfaces with thin layers of metal, polymer, or ceramic particles. The Vacuum Coating Technology (VCT) Group defines PVD as “a process where the material is evaporated in a vacuum and is then transferred to the surfaces of the substrate.”1 This technique is used in a variety of industries, from the production of semiconductor devices to the finishing of consumer products.
Physical vapor deposition works by passing high energy particles, typically atoms or clusters of atoms, through a vacuum. Once in this environment, the particles are highly energetic and vibrate rapidly. This motion causes chemical bonds to be broken as the particles collide with the substrate surface, resulting in the release of vaporized material that sticks to the substrate. The amount of vaporized material is proportional to the amount of energy passed through the process and the vaporized material’s vapor pressure. The thickness of the coating on the substrate is controlled by the energy and the duration of the process.
The PVD process can be used to form a variety of materials on surfaces. For example, PVD has been used to create wear-resistant coatings on mechanical parts and protective layers on the surfaces of medical implants. It can also be used to deposit thin films of gold, silver, and other metals. In addition, coatings such as chromium oxide and titanium nitride have been applied to produce a radiation-absorptive device for nuclear applications.
The primary advantages of PVD over other coating processes such as electroplating are environmental- related. It does not use any hazardous materials, and its emissions are much lower than other processes. PVD coatings also provide a higher degree of hardness, wear-resistance, and lubricity. However, some of the drawbacks of PVD include long processing times and high costs.
In conclusion, physical vapor deposition is an advanced technique used to coat surfaces with thin layers of metal, polymer, or ceramic materials. It is used in a variety of industries and has several advantages over other coating processes. It also has some disadvantages such as long processing times and high costs. PVD is an important technology with applications that range from the production of semiconductor devices to the finishing of consumer products.
