What you’ll learn:
- The importance of liquid protection against disinfectants.
- The flaws of traditional coating types such as conformal coatings.
- The future of liquid protection via nano-coating technology.
The ongoing COVID-19 pandemic means we’re increasingly becoming a more health-conscious society. As a result, we’re cleaning our personal devices more frequently than before, including phones, TV remotes, and game console controllers. In fact, one recent study revealed a staggering 92% of participants’ phones were contaminated with different types of bacteria.
Additional studies have shown that coronaviruses can persist on surfaces like metal, glass, or plastic for up to nine days. What’s more, 26% of U.S. consumers now clean their mobile phones daily, with a further 22% doing so at least once a week.
However, repeat cleaning of devices with alcohol- and acid-based disinfectants can damage devices unless the appropriate liquid protection is applied. In a P2i study, 83% of electronic product designers said that any device without liquid protection would fail within a year. So, what are the available liquid protection options, and which are best for electronic devices?
The Importance of Liquid Protection Against Disinfectants
Alcohol- and acid-based products are the two main types of typical domestic disinfectant, making them the most likely to be used on household electronic devices. It’s important to understand how the composition of these disinfectants can lead to damage within devices that don’t benefit from liquid protection.
In alcohol-based disinfectants, ethanol or isopropyl alcohol (IPA) typically make up 70% to 90% of the product along with a quantity of water to slow their evaporation. Both alcohols are strong wetting agents with high polarity; thus, they have an increased ability to bond to other molecules, such as water. Water contains minerals and salts that create high water conductivity within the disinfectant. This, combined with the alcohol properties, can lead to damage in unprotected electronic products.
Common acid-based disinfectants found in households typically contain one of two types of acid: hydrogen peroxide (H2O2) or hypochlorous acid (HCIO). H2O2 and HCIO are both oxidizers, meaning contact with components within electronic devices will lead to corrosion and dendrite formation.
Acid-based disinfectants also typically contain much larger proportions of water than alcohol-based products to stabilize and dilate the corrosive properties of the product’s composition. Adding water to the disinfectant won’t completely cancel out the corrosive properties of the acid, though, it will only slow it down.
In all disinfectant types, residual water can penetrate device openings and short-circuit internal components. However, there are a number of device protection options to prevent damage from disinfectants.
The Flaws of Traditional Coating Types
One traditional method of liquid protection is conformal coatings on internal components of devices. Conformal coating options include acrylic resin, silicon resin, polyurethane resin, and epoxy coating. While beneficial in protecting devices from adverse environmental conditions, composition and effectiveness can vary due to these coatings being applied in liquid states of differing thickness and quality.
The excessive masking requirements of conformal coatings also makes them inappropriate for protecting electronic circuits with complex geometry. Moreover, they’re prone to delamination and can require constant repair.
Mechanical seals are another traditional method of liquid protection. Options include platinum cure silicone, neoprene rubber, silicone rubber, and EPDM rubber. While widely used in electronics, some rubbers emit a sulfurous vapor that can damage electronic circuits. They also trap heat where microprocessors and operating components require cooling. On top of that, they can move position over time, which reduces their effectiveness. Separating mechanical seals from their main parts can prove to be problematic when recycling devices, too.
The Future of Liquid Coating
Liquid protection via nano-coating technology is a science-driven innovation. This technology can range from a splash-resistant application to protection against devices becoming fully submerged in water.
Unique to only certain nano-coating applications, specifically those associated with pulsed plasma technology, is their ability to prevent liquids from wetting the surface or penetrating an enclosure via capillary action, ensuring they’re truly liquid repellent. Stripboards protected with this type of nano-coating technology also show a significant improvement in electrical resistance compared to uncoated stripboards in personal devices.
While conformal coatings and mechanical seals can be potentially unreliable over time, nano coatings are not only beneficial to the end user, but also for stakeholders across the value chain. By allowing the life of a device to be extended, nano coatings help reduce e-waste and meet increased consumer demand for sustainable products.