Parylene is the common name of Poly-para-xylylene which prepared by the researcher in University of Manchester in 1947. It first applied to U.S military and aerospace industry after Union Carbide prepared parylene thin film via deposition technology, therefore, parylene coating was widely used in various areas includes parylene coated magnets due to the development of automotive vapor deposition equipment. The most common types of parylene are Parylene N and Parylene C.
Chemical Vapor Deposition Process of Parylene Coating
Chemical vapor deposition process of parylene coated magnet can be divided into three stages:
Stage 1: Solid di-para-xylene will be sublimated to the gas phase under 120 degrees Celsius and vacuum condition.
Stage 2: Di-para-xylene gas further decompose into reactive monomer after pyrolysis reaction under 650 degrees Celsius.
Stage 3: Reactive monomer deposit on the surface of the magnet after entered deposition chamfer and thus polymerized between each other.
Advantages of Parylene Coated Magnet
- Unlike regular surface treatment technology, parylene is well adapts for small sized magnets and micro magnets.
- Parylene coated magnets are free of pin holes due to the vacuum deposition process which reactive monomer filled into the cracks.
- Parylene coating have excellent stability under high temperature.
- Parylene coating also exhibit superior anti-moisture ability.
- Parylene coating is not merely a kind of chemical resistant coating, but also a biocompatibility coating which ensured its applications in medical area.