What is PVD coating?
Physical vapor deposition (PVD) is a type of vacuum deposition and is a general
term used to describe any of a variety of methods to deposit thin substrates by
the condensation of a vaporized form of the material onto various surfaces
(e.g., onto semiconductor wafers). The coating method involves physical
processes such as high temperature vacuum evaporation or plasma sputter
bombardment rather than involving a chemical reaction at the surface to be
coated as in chemical vapor deposition.
How does the PVD process work?
The high-purity, solid coating material (metals such as titanium, chromium and
aluminium) is either evaporated by heat or by bombardment with ions
(sputtering). At the same time, a reactive gas (e.g. nitrogen or a gas
containing carbon) is introduced; it forms a compound with the metal vapour and
is deposited on the tools or components as a thin, highly adherent coating. In
order to obtain a uniform coating thickness, the parts are rotated at uniform
speed about several axes.
The properties of the coating (such as hardness, structure, chemical and
temperature resistance, adhesion) can be accurately controlled.