Parylene Coating For Magnets

Enhance the resilience and longevity of magnets with our superior Parylene Coating. This cutting-edge, ultra-thin protective layer promises excellent resistance to solvents, chemicals, and moisture, safeguarding against environmental and operational damage. With adequate insulation properties and a clear, conformal finish, it’s optimal for maintaining the magnetic force in delicate applications. Utilize our Parylene Coating solution for electronics, medical devices, and any scenario requiring robust magnet protection without added bulkiness. Trust our Parylene Coating to deliver consistent performance and pristine condition for your magnets.

Parylene Coating For Magnets

We use the Parylene covering to safeguard neodymium magnets, especially tiny magnets for medical uses and various electrical, medical, and commercial goods. Their width typically varies from 100 nanometers to 1 millimeter.

We typically add it using a chemical vapor deposition method. The method first vaporizes the polymer before depositing it in a thin, homogenous coating on the material’s surface.

Parylene is highly adaptable to complex forms and patterns. One of its primary benefits is that it is suitable for various surfaces. It also has excellent electrical shielding properties and is impervious to dampness, toxins, and Ultraviolet radiation.

We commonly use Parylene protection in the production industry to protect electrical devices from rust, dampness, and mechanical damage and to shield and secure wire ties, connectors, and other components. Because of their biocompatibility and capacity to defend against illness, they are also common for medical equipment and prostheses in the medical sector.

Parylene coated magnet

Basics Of Parylene Coating

The Parylene coating process is built on a particle in the coating equipment’s evaporation furnace. The solid substance is biochemically converted into a gaseous state under pressure at 150°C (302°F).

The diffuse substance is then split into volatile molecules via high-temperature pyrolysis at 650-700°C (1,202°F – 1,292°F). The atmospheric monomers are applied and polymerized at ambient temperature at the nanoscale using CVD.

To summarize, Parylene covering is extensively used to improve security performance in aircraft, microelectronics, transistors, sensors, magnetic materials, medical devices, cultural artifacts preservation, and other areas.

Features Of Parylene Coating

The vapor deposition process for Parylene coating has the unique protective features listed below. 

  • Good resistance to salt spray, oxidation, and humidity 
  • No curing heat stress 
  • No negative influence on magnetic properties 
  • Near peer, good adaptability to complex shapes 
  • Can fill micro holes and gaps 
  • No pinholes and “sand holes,” and other coating defects 
  • Ultra-thin and strong insulation coatinga layer of 5micron coating can meet the voltage shock of thousands of volts 
  • Micron-level coating thickness is uniform and controllable 
  • Significantly save space of magnetic surround line 
  • It can increase the strength of magnets, suitable for samarium cobalt and other materials. 

1) Non-Porous Parylene

the covering is composed of thin polymer layers containing active small molecules that “grow” on the surfaces of objects. Because they are formed under vacuum conditions, they can be applied to various shapes, including sharp edges, cracks, and internal surfaces.

2) Totally Pinhole-Free

Heating and melting of xylene cyclo dimers are followed by high-temperature breaking into free gas phase molecules, which are immediately deposited onto the substrate under vacuum and room temperature circumstances to polymerize into a film, creating a very impermeable protective layer.

Because perylene coating contains no solvents, it overcomes the flaws of previous solvent-based coatings, which unavoidably left many small pinholes due to solvent loss during the curing process. This feature ensures that the covering coating has no pinholes.

This property benefits neodymium magnets whose uses require direct interaction with different moistures and liquids. One typical example is a countersunk neodymium magnet used for closing within industrial valves. You don’t have to worry about something leaking inside and damaging the neodymium magnets.

3). Independent Security

Points And Overall Security
Experiment after experiment revealed that each point of the Parylene coating is an independent protection point. When the covering of a specific location is harmed, the neighboring regions of the coating are unaffected. At the same time, the ends of the coating layer are chemically bonded together, providing uniform and enhanced defensive performance.

4) Adequate Ventilation

In addition to these inherent properties, Parylene-based coating has good electrical properties, good power-saving properties (low dielectric loss and high dielectric strength), and excellent mechanical properties (high mechanical strength and low coefficient of friction), making Parylene a suitable insulating layer for small wound components. The high dielectric strength and dry film lubricity of perylene make it ideal for this application.

5). Spiral Viewing Room

The thin and consistent layer of the Parylene covering enables the winding device to keep a reasonably sizeable winding window. The large winding area that results permits it to be used as a covered product with improved performance—coated goods.

Parylene is also used for components that would be “inclusions” in conventional materials and for small ferrite transformers and voltages. Parylene does not suffer from magnetostriction or permeability issues, unlike traditional impregnation methods.

Winding apertures are critical for tiny moveable and rotor assemblies, and coating bonded nickel-iron laminated components with urethane or PTFE materials is typically challenging. Because of the complicated form and coating material that will remain in the tiny winding opening and the coating with very little surface tension that will stay on the pointed exterior edges will cause significant friction when winding. Whereas regular and constant Parylene maintains these tiny window openings while ensuring adequate covering thickness on the outer edges to provide wind protection.

6). Excellent Tiny Magnet Plating

Insulating between the coil and the metal component with tape is conventional; however, using video is challenging when the part is very tiny. Covering with Parylene can help remove faulty components while improving their electrical characteristics. An example is the small cylindrical core used in some hearing aids as a “Pick-Up” coil.

7). Increased Power and Resilience to Erosion

New advancements in magnetic materials have created sintered and cemented NdFeB components that can be produced in tiny forms and have exceptional benefits when using the Parylene covering method. Small NdFeB magnetic devices are brittle, and adding a Parylene coating improves their strength. The NdFeB substance is also susceptible to rust from atmospheric moisture, and Parylene’s meager water vapor transfer rate offers excellent moisture and corrosion protection.

Different Types Of Parylene

Technically speaking, Parylene coating includes types such as Type N, Type C, Type D, Type F, and Type AF4. They differ in terms of their chemical structure and properties. 

1) N Perylene
It is an excellent dielectric substance with minimal dielectric loss, high shielding strength, and a dielectric constant that does not change with frequency.

It is a Parylene layer with significant penetration, excellent self-lubrication, and a coefficient of friction of 0.25. It satisfies the ISO-10993 biological test requirements and the UDP Class VI polymers physical test requirements.

2) Paraylene C.
This is the series’ second widely accessible variant. It has excellent electrical and physical characteristics and low susceptibility to dampness and other toxic vapors. It has the potential to provide a genuinely pinhole-free coating of security.

It is a covering substance for crucial circuit boards that satisfies US military specification MIL-46058C. It also passes the ISO-10993 biological test for UDP Class VI polymers.

3rd) Parylene C
This variety is comparable to Parylene C, but it can resist fire. It retains outstanding electrical, physical, and dynamic characteristics at more excellent temps.

4). F. Parylene
This variety has a solid dielectric strength, a low dielectric constant, excellent temperature stability, and Ultraviolet resistance. The film itself is continuous, thick, and clear of pinholes. It is a perfect protective coating for a wide range of complex-shaped electrical equipment.

5) Parylene AF4 is the number
This form of Parylene covering has a high dielectric constant, excellent stability, and resilience to water, dampness, and saline precipitation.

It is resistant to short-term temperatures of up to 450°C (842°F) and long-term temperatures of up to 350°C (662°F), as well as intense Ultraviolet rays.

It is better suited as a shielding substance for high-frequency radio equipment. Furthermore, it meets the ISO-10993 biological test criteria for UDP Class VI polymers.

Applications Of Parylene In Medical Products

The Parylene covering is bio-soluble as well as chemically and electrically safe. The FDA has approved it as a biological substance that can be inserted into the body for long-term use.

Some medicinal gadgets contain electrical components that must be meticulously safeguarded. These electrical components are minuscule and lack the sufficient weight to submerge, spray, or paint. Some little devices are also harmed by air spaces, irregular thickness, and other factors, so we cannot use conventional protective covering.

Parylene coating is increasingly replacing TiNi (nickel-titanium) covering as the option for biomedical devices in foreign clinical uses due to its good anti-oxidant, low impediment, low friction coefficient, and biocompatibility.

Bone nails, probes, needles, temporary surgical instruments, catheters, brakes, cochlear implants, cardiac pacemakers, brain electrodes, implantable sensors, radiofrequency therapies, blood analysis sensors, high-frequency scalpels, and other micro-electronic medical devices are typical examples.

Compliances Of Parylene Coating

Parylene coating is widely used in medical device products due to the following properties. 

  • Complies with ISO-10993 biological testing requirements 
  • Complies with FDA G95-1 
  • Complies with (ROHS) 2002/95/EC 


Below are some examples of medical products that use Parylene coatings, briefly introducing their advantages. 

  • Cardiac assist devices – Such as pacemakers and precision electronics in electroshock generators, sealed with Parylene against corrosion by biological fluids and protects the metal housing. 
  • Pressure sensors – Blood pressure sensors, where depositing a small amount of Parylene, provide adequate insulation and do not significantly alter the operation of these devices. 
  • Alternative devices – Such as resilient man-made devices, protected with Parylene, eliminating problems associated with microscopic transport and protecting against corrosion by biological fluids. 
  • Ultrasonic transducers – Microsensors used to observe the lining of blood vessels are protected from corrosion and breakdown with Parylene coating. 
  • Bone growth stimulator – With Parylene, this device can be isolated from biological fluids. Human cells can quickly grow with the Parylene surface to form a thin tissue of the same structure. 
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