Understanding Antifungal Conformal Coatings

Many electronic components are manufactured with a conformal coating which adds protective properties, or the coating can be purchased separately to apply as needed. Some products may be listed as “antifungal” or “fungal resistant”, and there may be some confusion regarding the actual mechanism which induces these properties. The level of protection may also vary despite having the same label.

Searching for the keyword “conformal” from the Digi-key home page gives any user a general idea of the products that may include this type of protection: [click here https://www.digikey.com/ ] > “conformal”

A truly antifungal coating that doesn’t include additives must be inorganic. The clear line between ‘antifungal’ and ‘resistant to fungus’ is whether or not the coating can be broken down into nutrients (food) for the fungus. In general, inorganic coatings such as silicone will not be targeted by a fungus as an actual source of nutrients, so the most that may occur is growth over, around, or under the coating if conditions allow for it. The coating will remain intact.

Organic coatings will vary in the degree of fungal resistance, but they essentially become targets based on the fact that the molecular structure is recognized as a possible nutrient to fungal organisms, and the digestive mechanisms of fungi are designed to break down organic substances for this purpose. Products that exhibit moisture resistance create a less suitable environment for microbial growth, but many acrylic, polyurethane, and organic epoxies will still fail to fungal attack.

Both organic and inorganic coatings may include additives to help prevent fungal growth. These are substances that physically and/or chemically interfere with microbial reproduction. The product information (datasheets) may list the actual chemical makeup of the coating, or it might be found on the manufacturer’s site. A request can also be sent to the supplier for more information regarding the material composition of the product.

Conformal coating products that can be purchased separately are shown in the following link: [click here https://www.digikey.com/short/z0m889 ]. Product Index > Prototyping, Fabrication Products > Coating, Grease, Repair > “Coating” or “Conformal Coating”

Example: ACL Staticide Inc. Silicone Conformal Coating, Product Code 8695 [click here https://www.digikey.com/short/z0m841 ]. Product Index > Prototyping, Fabrication Products > Coating, Grease, Repair