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How Parylene Protects Electronics in Harsh and Hostile Environments

Posted by diamondmtblog

Wednesday, July 28, 2021 1:03

@ 1:03 PM

Parylene comes from a series of polymers from paraxylene and is often used as a coating that safeguards electronic devices. Specifically, parylene coating is a conformal coating created directly on surfaces at room temperature using a chemical vapor deposition (CVD) process. For many facilities and industries, parylene shields electronics from contamination, corrosion and complications arising from exposure to harsh and hostile environments.

Parylene Coatings for Electronics in High-Risk Applications

There are six main types of parylene:

1. Parylene N: This material is the most basic form of polythene. With its linear structure and high crystalline content, the chemical compound has high dielectric strength. It penetrates narrow crevices and conforms to surfaces with contoured topography.

2. Parylene C: Parylene C is the most commonly used type. It has the same structure as Parylene N with an added chlorine replacing a hydrogen atom. This slight difference allows for a quick deposit rate. It has low permeability to protect against corrosive gases and moisture.

3. Parylene D: This material begins with hydrogen and carbon, the same building blocks as Parylene C, but has two chlorine groups. It provides a higher temperature range and surface resistivity at the expense of lower dielectric strength.

4. Parylene F: Parylene F is fluorinated, making it resistant to high temperatures and ultraviolet (UV) radiation. For direct sunlight exposure and low electric currents, Parylene F is an optimal coating.

5. Parylene HT: This Parylene variant is the newest commercially available variant and is also capable of heat resistance and long-term UV stability. Parylene HT replaces the alpha hydrogen atom of the N dimer with fluorine, and it’s ideal for high-temperature environments of up to 450 Celsius.

6. Parylene AF-4: Parylene AF-5 has the highest UV stability and oxidative resistance of any Parylene type. However, its yield is limited and usually designated for specialized uses due to the complicated nature of its three-step synthesis manufacturing process.

Qualities of Harsh and Hostile Environments

For electronics, harsh and hostile environments can be anything from medical facilities to military battlefields — any place with rough conditions qualifies and merits extra protection for electronic components. These locations are where products need protection from water, fungus, vehicle fluids and other elements.

Risks for Electronics in Adverse Conditions

As so many objects and systems require electronics, it’s inevitable that many will encounter harsh environments. Common dangers to electronics include exposure to:

• Extreme temperatures and fluctuations.

• Contamination from dirt or dust.

• High humidity and moisture.

• Excess shock or voltage.

• Stress or impact damage.

Benefits of Using Parylene for Electronics in Harsh Environments

With parylene coatings, you can protect your electronic devices from those risks. Parylene for electronics in harsh environments has benefits such as:

• Biocompatibility: The Food and Drug Administration (FDA) has well-documented approval for medical devices containing parylene being placed in the human body. The coating complies with the United States Pharmacopeial (USP) XXII Class VI plastics requirements and biocompatibility rating.

• Conformity: Properly applied parylene coating is pinhole-free with uniform controllable thickness greater than 0.5 micrometers to 1 millimeter on any surface or design.

• Durability: The formation process ensures lightweight, protective performance over time. Parylene has high-quality barrier, physical and electrical properties.

• Stability: All types of parylene have high melting points. This substance can withstand temperatures from minus 200 degrees C to 200 degrees C.

• Permeability: As this material is nonporous and resistant to moisture and gas, it’s difficult for foreign materials to infiltrate the surface.

• Protectablity: Parylene coating penetrates spaces as narrow as 0.01 millimeter for protection on virtually any surface of a part.

• Resistability: Parylene is unaffected by solvents, acids, chemicals and other substances and can pass a 100-hour salt-spray test.

• Versatility: A variety of industries use parylene conformal coatings for circuit boards, medical devices and other equipment.

• Invisibility: The clear, thin layer of a parylene coating is transparent, making it invisible to the human eye.

Industries That Use Parylene: How to Protect Electronics in Hostile Environments

Without sacrificing functionality, parylene protects electronics in harsh environments. Various industries take advantage of parylene conformal coating to expand the applications of their devices, including:

• Automotive: Manufacturers and mechanics use electronic devices and computer chips in vehicles. These critical components need protection from vehicle fuel and fluids like battery acid, antifreeze and oil.

• Defense and aerospace: Military personnel and pilots operate aircraft that need stability for accessible and reliable technology. Their devices must withstand conditions with varying temperature changes, weather patterns and chemical exposures.

• Electronics: Electrical technicians and engineers place printed circuit boards (PCBs) and programmable logic controllers (PLCs) into various devices. These sensors and equipment demand safeguarding against damage from UV rays, dirt and water.

• LEDs: Electricians and electrical contractors use light-emitting diodes (LEDs) for energy-efficient traffic signs, billboards and other lighting options. LEDs need to handle conditions where heat, water and other factors cause harm.

• Medical: Doctors and surgeons insert medical devices into the human body. As the body resists foreign objects, medical devices must survive a hostile environment where sweat, fluids and biological factors could cause damage.

• MEMS: Many industries deal in microelectromechanical systems (MEMS) with small pieces and complex parts for consumer electronics and various applications. These devices and systems need protection from harmful environmental conditions, including temperature extremes, abrasive liquids and stiction.

Contact Diamond-MT for a Quote on Parylene Coatings for Electronics

Diamond-MT offers reputable and reliable services for your parylene coating needs. We also maintain a strict program per NSI ANSI Standard 20.20 for ESD protection, and thanks to our extensive experience, we know how to protect electronics in harsh environments.

Standard orders ship in 10 business days. For orders needed quickly, we offer expedited service where we can return your order in as little as two to five business days. If you’re looking for a company that can provide parylene conformal coating solutions for clients across the globe, contact us today for a quote.