Parylene: Making a Difference Across Many Markets

Parylene conformal coatings are used in many different industries. With their hardness, chemical inertness and ability to perfectly coat any surface, they have expanded well beyond their original military and aerospace applications. Whether it’s a protective coating for an LED or a protective shell around a coronary artery stent, the compound is found in places where you might not expect to find it.

Medical Applications

Within the healthcare industry, Parylene enhances device functionality, longevity and compatibility with the human body. Medical device manufacturers rely on Payrlene’s unique properties, whether it is to coat needles for easier skin penetration or shield delicate defibrillators from the body’s saline and chemical environment. For instance, stents utilize the compound not only to safeguard their intricate wire latticework but also to regulate drug release from their surface.

Transparent and flexible, Parylene complies with the requirements of a USP Class VI plastic and can be applied as a film in layers as thin as 0.1 mil to provide a pinhole-free conformal coating, even on complex surfaces common in medical applications.

One important attribute of Parylene for medical coatings is its superior dry-film lubricity, with static and dynamic coefficients of friction approaching those of Teflon™ (in the range of 0.25 to 0.33 per ASTM D 1894). Typical applications in this regard include a variety of elastomers and seals as well as the coating of mandrel wires used in the manufacture of balloon catheters.  Additional applications include small diameter lead wires used inside flexible catheters which must be electrically insulated, chemically protected, and capable of moving easily against the catheter surfaces in extremely tight quarters. Prosthetic components such as attachment sleeves and even bone pins also benefit from the lubrication properties of Parylene to prevent skin irritation and metal corrosion. In addition, Parylene’s hydrophobic and lubricious nature can minimize residual fluid buildup on both the inner and outer surfaces of needles and other medical components, thus enhancing performance and aiding cleanup.

Electronics and PCBs

Parylene’s initial use was to coat electronic components and printed circuit boards. Its distinctive blend of protective properties renders it exceptionally suitable for this purpose.

• Parylene’s dielectric properties allow it to serve as an insulator for the traces on the board. This allows manufacturers to make smaller PCBs without having to worry about crosstalk and interference.
• The unique vapor deposition method allows it to penetrate extremely small spaces — like between the pins and underneath soldered-on integrated circuit (IC) chips.
• Masking ensures precise deposition of the compound without obstructing areas essential for conductivity.

Automotive

Automotive components endure a variety of challenges. They face intense heat within the engine and exhaust, endure freezing temperatures in northern regions and are constantly bombarded by dirt, often blowing past sensitive parts on the highway. While Parylene can protect the electronics in vehicles, another of its strengths is in protecting the micro-electromechanical systems (MEMs) that are used in many sensors. When dealing with components measured in micrometers or nanometers, Parylene’s skill in safeguarding delicate technologies through ultra-thin coatings, often measured in angstroms, proves to be a perfect fit.

Aerospace and Defense

First used extensively in aerospace and defense applications, Parylene remains an extremely popular choice in these industries. Unlike some other coatings, the compound is extremely tough, making it able to protect components so that they can meet stringent specifications like MIL-STD-810. Here are some of its benefits:

• Hydrophobic — It repels humidity and water. It can even withstand 100 hours of salt-spray.
• Thermal endurance — Parylene HT^®, the high temperature variant, can withstand continuous exposure to 350°C.
• Chemical resistance — Parylene resists acids, bases and solvents.
• Lightweight — When applied in ultra-thin coatings, it is highly effective, adding virtually no weight or bulk to the item it is used on.

LEDs

Light-emitting diodes (LEDs) have very unique properties. They produce constant, pure light while consuming very little power and generating little heat. Unfortunately, they are also sensitive electronic components that are not well suited for the harsh outdoor world. Between the abrasion damage that blowing dust can cause to a traffic light or the UV-induced yellowing of an outdoor display screen, LEDs should need protection. Parylene serves not only as a surface protector for LEDs but also offers light-filtering capabilities that effectively combat the LED’s gradual yellowing and fading.

No matter your industry, Parylene conformal coatings can enhance your product quality. Contact us to discover how this technology can elevate your operations.