Conformal Coatings

Due to the wide array of applications utilizing Centon’s NAND Flash and DDR memory, and the often hostile environments that these products are subjected to, Centon Electronics offers its application specific solutions with conformal coatings in order to insure the longevity of the product in any environment.


Conformal coatings are a thin non-conductive dielectric film that can be brushed on, sprayed on, or applied by dipping the PCBA. This protects the components on the board as well as solder joints, and other exposed areas. This also helps strengthen the board against thermal and/or mechanical stress.

There are different types of Conformal Coatings, so what are the differences?


Conformal coatings are typically classified by type and physical properties:


Urethane resin - This coating has excellent chemical, humidity, and mechanical wear resistance, but it suffers from longer cure times with a risk of peeling. It’s also somewhat difficult to remove in the event rework or repair is needed.


Parylene - This coating has the best resistance to extreme temperatures and solvents, along with a high dielectric strength. The coating forms at room temperature and doesn’t require any time for curing, but it‘s difficult to remove. It also requires chemical vapor deposition equipment, and it’s not rated very highly for outdoor exposures of long duration.

Acrylic resin - This coating is easily applied and removed and is easy to work with. It has a low resistance to chemicals, solvents, and abrasion, and is not the best for high temperatures and really harsh environmental conditions.


Epoxy resin - This coating has strong abrasion, moisture, chemical, and humidity resistance and provides excellent protection in harsh environments. It is however difficult to remove, and it can shrink during curing.


Silicone resin - This conformal coating performs really well in extreme temperatures, and has excellent humidity & corrosion resistance, and good chemical resistance. It also adheres well to the majority of PCBA materials and components. However, it’s the most difficult coating to remove requiring chemical solvents or aggressive abrasion.


Benefits of Conformal Coating


Conformal coatings have several strong selling points, which is why it's used so often in critical applications.

These benefits include:


Extended service life: Conformal coating prolongs the life of the product during its operation. Since devices last longer, they will be more reliable and save costs associated with repairs and warranties.


Nonconductive properties: Conformal coatings help increase the dielectric strength between conductors, enabling the design of the PCBA to achieve higher layout density.

Lightweight: Conformal coatings are very thin, adding virtually no discernable bulk to the product. It's an ideal alternative to heavy-weight protections like mechanical seals and complete enclosures.


Protection: Conformal coatings protect integrated circuits and passive components from abrasion and other corrosive agents.


Security: Conformal coatings create a tamper resistant surface and prevent electronic intrusion.


So in summary, conformal coating is a protective, nonconductive, dielectric layer that is applied onto the printed circuit board (PCB) assembly to protect the electronics from damage due to contamination, salt spray, moisture, fungus, dust and corrosion caused by harsh or extreme environments.


Applications


Conformal coating electronics solutions is typically focused on mission critical military, aerospace, automotive, marine, transportation, medical equipment and industrial uses. They are also being used for common consumer electronics products more and more, as costs continue to come down due to process automation and economies of scale take effect.


Standards


Because there are focused Standards and Specifications with regards to conformal coatings as set forth by the IPC (The Global Association for Electronics Manufacturing) and other organizations, it makes sense to list those for clarity and informational purposes.


IPC-CC-830C: Qualification and Performance of Electrical Insulating Compound for Printed Wiring Assemblies


This is the main standard for conformal coating. It was created to provide an alternative to the older MIL-I-46058C standard when it was deactivated. 830C is used to qualify different conformal coating products, and contains sections on materials, shelf life, curing, chemical, viscosity, and appearance requirements. It also contains standards on fungus, moisture, and flammability resistance as well as dielectric withstanding voltage and other electrical specifications. This standard is an active specification and is updated with new information as needed. The latest “C” release was published in January of 2019.


IPC-A-610G: Acceptability of Electronic Assemblies


This standard covers the acceptability of electronic assemblies and has a section on the requirements for conformal coating coverage and thickness.


IPC J-STD-001F: Requirements for Soldered Electrical and Electronic Assemblies


This standard covers the requirements for soldered electrical and electronic assemblies, and has a section dealing with materials and application of conformal coating.

There are also some other standards that include specifications and requirements from the military and Underwriters Laboratories for conformal coating:


MIL-I-46058C: This is the original military grade standard for conformal coating. 46058 was deactivated in 1998 for new designs, and IPC-CC-830 was created to replace it. Since the two specifications are similar, conformal coatings that have been qualified to MIL-I-46058 are considered to have met the requirements of IPC-CC-830.


UL94: This is an Underwriters Laboratory standard that certifies the ability of a conformal coating to self-extinguish a flame on a circuit board substrate (FR-4).

UL746E: This is another UL standard that covers the test procedures for the physical, electrical, flammability, thermal, and other properties of the materials, including conformal coating, used in printed circuit boards.


Centon Electronics offers this value added service for your NAND Flash and DDR memory solutions, and we will work with you directly to determine the best coating option based upon a few factors, such as the intended application, environmental exposure and implementation. For example, devices used outside need moisture and vapor protection, coatings on medical devices need to be biocompatible and electronic power applications require anti-corrosive coatings.


Contact us so that we can provide you a solution that specifically meets your needs.


Contact us

Leave your message and we'll get back to you shortly.

Thanks for getting in touch! 


We appreciate you contacting us. One of our colleagues will get back in touch with you soon!


Have a great day!

Thanks for getting in touch! 


We appreciate you contacting us. One of our colleagues will get back in touch with you soon!


Have a great day!