What is the standard PVD coating for electrical insulation purposes?

Question

I want to insulate some copper parts with a thin coating. I am interested in a physical vapor deposition (PVD) process, but I’m not sure if PVD is suitable for the deposition of an electrically insulating coating. A lot of PVD providers seem to be coating parts for the purpose of wear-and-tear protection not electrical insulation, and from what I have read the coating material often seems to be some kind of metal. The durability sounds really great because my parts will be exposed to high pressure running water, but I need to insulate the parts with a non electrically conductive coating. Is PVD used to deposit electrically insulating coatings? If so what is the specific coating material(s)? 

Answer 1

Asking about PVD to solve an insulation issue seems entirely too specific, or contrived, or at best an X-Y question (better: "what insulation methods can be easily applied to exposed surfaces without contact e.g. as a spray or gas?"), especially if you "aren't sure" if PVD is even suitable, if such a process exists in the first place.

But, since you ask, there does in fact happen to be such a process.

Parylene is an aromatic polymer, that can be evaporated, which links together on contact with a surface. See: What is Parylene Coating? | VSI

Answer 2

It’s used to make better conductors but I read Palladium Tantalum is used for PVD insulation but must be expensive.

So plastic with multiple coaxial layers is used. Copper being malleable makes the electrical insulation fail in some coatings.

Magnet wire is good when permanently installed with care and protection but not cheap.

You are best to use existing Waterproof Cable / Water-Resistant Cable or “submarine category cables ”