This PVD coating process physically deposits particles extracted from a target surface by ejecting the particles towards the substrate. Sputtering sources are "magnetrons" that utilize strong electric and magnetic fields to trap electrons close to the magnetron (target). Mechanical pumps remove air and contaminants while lowering the chamber pressure to a negative atmosphere. The electrons follow helical paths around the magnetic field line and are deposited as the substrate (part) moves by the target.
As an end result, this process provides a smoother, more uniform film deposit and tighter grain structure. Parts with "complex" geometry or precision tolerances are better served using this process. Application examples include optical films, semiconductors, architectural glass, and medical instruments. Like all PVD applications, sputtered films offer distinct advantages over traditional electroplating.
While there are many materials that are applied using this system, the most common "targets" used include: Titanium (Ti); Zirconium (Zr); Chromium (Cr); Gold (Au); Silver (Ag); Tungsten (W); Copper (Cu) and Hastelloy.