Isoflux is the world leader in inverted cylindrical magnetron (ICM) sputtering. But why would you want a cylindrical magnetron? Excellent question!
Ultimately it depends on your application, but there are a lot of reasons to consider an ICM:
You are coating a complex geometry.
Sputtering is a line of sight process, so planar targets are good at coating flat objects. Sputtering from the inside of a cylinder sputters material from all sides at once, so coating complex geometries uniformly is much easier. Whether the device is a coronary stent, a machine tool, or even just a wire or cylinder - coating from all sides at once enables a high degree of uniformity without complex motion and masking.
You require a high degree of uniformity, for flat or complex parts.
If your geometry is complex, it's easy to see why an ICM