Vehicle management systems for emissions, lighting, fluid monitoring, powertrain and fuel systems are increasingly comprised of high-tech electronic systems that often come in highly miniaturized, multi-layer packages. These devices and materials must be able to survive hostile automotive environments that include high temperatures, corrosive fluids and vapors, and prolonged UV exposure.
For nearly 40 years, Parylene has protected automotive components such as circuit boards, sensors, MEMS and gaskets, to name a few components. Parylene coatings are ultra-thin, pinhole-free and completely conformal, and provide excellent moisture, chemical and dielectric barrier protection. Parylene HT® offers increased UV and thermal stability (350°C long-term) for components that must survive harsh automotive environments.
Parylene conformal coatings are well suited to protect critical components within many applications, including emission monitoring systems, power train control systems, tire pressure monitoring systems; fuel system components, and engine/fluid monitoring systems.
The electronics industry is moving toward miniaturization with very high delivery capacity/multi-tasking products. These products are continually demanding more in application capabilities within smaller spaces.
Parylene coatings provide excellent moisture, chemical and dielectric barrier protection to a variety of electronic components. Parylene is applied in a vapor deposition process, ensuring an ultra-thin coating that penetrates into even the smallest profiles and crevices of electronic packages for complete encapsulation. Because there is no liquid phase in the deposition process, there are no subsequent meniscus, pooling or bridging effects as seen in the application of liquid coatings, thus the coating’s excellent dielectric properties are never compromised.
Ultra-thin Parylenes protect components such as circuit boards, sensors, MEMS, multi-layer packages, and LEDs for use in a wide variety of applications, including hydrocarbon drilling, utility meters, audio systems, industrial monitoring systems, agricultural equipment and high voltage electrical connectors.
SCS Parylenes are RoHS compliant and have been shown to mitigate metallic whisker growth.
LEDs (light emitting diodes) are miniaturized solid state technologies that are energy efficient, environmentally friendly and small in size. Today’s LED technology can be found in a wide array of applications from large video displays, outdoor illumination and transportation signage, all the way down to the latest technology in smart cell phone displays. The never ending goal of LED technology is to make all types of displays brighter, longer lasting and more dimensional.
Conformal coatings such as silicones, acrylics, urethanes, and potting compounds were sufficient for older types of electronic assemblies. However, liquid coatings are often uneven and thus, may have voids, which are pathways for moisture to get through to the underlying circuit board and cause performance failure of the LEDs. These failures can be expensive when considering the large number of LED boards used in many digital display and video signage. Additionally, the heaviness of many standard coatings is a drawback as they can induce stresses to delicate components.
Parylene coatings are extremely lightweight, offering excellent barrier properties without adding dimension or significant mass to delicate components. Additionally, Parylene coatings are optically clear and are UV stable.
Ultra-thin and pinhole-free, SCS Parylene conformal coatings are biocompatible and biostable. Parylene coatings provide excellent moisture, chemical and dielectric protection, in addition to dry-film lubricity, to a host of medical devices and components, including stents, pacemakers, needles, catheters, electrosurgical tools, cochlear and ocular implants, and elastomeric components.
Parylene is applied in a vapor deposition process, ensuring an ultra-thin coating that penetrates into even the smallest profiles and crevices of the components being coated. Because there is no liquid phase in the deposition process, there are no subsequent meniscus, pooling or bridging effects as seen in the application of liquid coatings, thus the coating’s excellent properties are never compromised.
SCS maintains Device and Drug Master Files with the U.S. FDA. These files, which include the results of biological studies on SCS Parylenes, are available for reference by all SCS commercial coating service customers.
Parylene is a Mil-Spec approved conformal coating that has been in use for over 40 years in military and aerospace applications. Parylene N, C and Parylene HT are listed on the QPL for MIL-I-46058 and are also recognized as meeting the requirements of IPC-CC-830.
While all Parylene formulations have an extremely small molecular structure, Parylene HT is the smallest of all. Because of this, it can penetrate extremely small areas, providing complete coverage without compromising operational capabilities. It also provides long-term thermal stability up to 350°C (short term up to 450°C).
Military applications have long-benefited from the properties of vacuum-deposited Parylene films. Due to the fact that Parylene is applied in a vacuum deposition process, there is no potential for trapped air pockets within or under the coating. Such air pockets can open when exposed to altitude, creating a pathway for a short circuit.
Parylene has been used to protect various military components such as circuit boards, sensors, multi-layer packages, LEDs, and elastomeric components. These components and more can be used within a variety of applications, including aircraft control systems, radar systems, armament control systems, and engine control and monitoring systems.
Parylene conformal coatings have protected devices and components used in space applications for a number of years, covering virtually everything from wiring and cabling assemblies and camera components to power supplies for various systems and components internal to the vehicle itself.
Parylene coatings provide excellent moisture and dielectric barrier protection for electronic components, such as circuit card assemblies, PCBs for control systems, and components used in various support/controls systems, all which need to withstand the atmospheric, temperature and pressure changes of a launch. In addition to protecting components from moisture condensation that occurs with the rapid altitude shifts, Parylene also restricts outgassing and protects components from the high level of vibrations that occur. Parylene actually strengthens delicate wire bonds and connections by 10x to ensure continued reliability of the connection.
Finally, Parylenes do not exhibit changes in mechanical properties with changes in temperature as other materials do. In oxygen-free atmospheres or in the vacuum of space, the continuous service temperature projections exceed 200 °C for Parylenes N and C. Parylene HT has the ability to resist thermal oxidation up to 350 °C (long-term) in both oxygen and oxygen-free atmospheres.
For more information on Parylene products contact:
Tim Seifert, Electronics Market Specialist, Specialty Coating Systems
(317) 244-1200, ext. 220
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