Filling electronics components with potting resin is a practical and proven way to protect them. Selecting the most appropriate potting resin for electronics is an essential step to ensure products perform as expected.
However, the selection process varies according to several factors. Here are some helpful steps to consider to reach the most informed, confident decision.
Determine the ideal resin characteristics
Epoxy, polyurethane and silicone are some of the leading potting resins used in the electronics sector. Epoxies have good physical strength, along with chemical and electrical resistance properties. They’re also ideal when people need potting resin to tolerate environmental stresses.
Suppliers usually sell polyurethane as two-part products that remain stable in the presence of ultraviolet rays, offer good electrical insulation and adhere well to most substrates. Some polyurethane potting resins also withstand temperature extremes, making them good choices for sensor encapsulation. People can also buy one-part polyurethane resins. However, they should remember those options won’t provide adequate moisture resistance, even after curing.
A report from Research Dive positioned silicone as a market leader when used as a potting resin for electronics. The March 2022 coverage forecast that the sector will show a 4.5% compound annual growth rate through 2028. While detailing the various advantages of such potting compounds, the report mentioned how silicone tolerates an extensive temperature range from about 50-400 degrees Fahrenheit. Silicone also protects parts against corrosion and is easy to remove, unlike other compounds.
Thinking about the most desirable properties of a potting compound will help people make the best choices about which ones to use for products containing sensitive electronics.
Consider the biggest risks to potted components
Choosing potting resin for electronics also requires people to think about the most significant threat to the electronics over their useful life. The best potting resin for the electronics inside an outdoor light or sign will differ from the most appropriate choice for a product that will never or rarely get exposed to the elements.
However, some threats pose problems to all electronics. Electromagnetic interference (EMI) is a good example. People use materials ranging from stainless steel to fabric with embedded metal to protect components from EMI. Electronics designers also typically account for their products' electrostatic discharge. That release of static electricity can come from humans during the routine use of electronics.
However, researchers recently modified compounds to make electrostatic discharges dissipate. They confirmed an electrical magnitude volume resistance reduction equal to 12 orders of magnitude. The team worked with silicone and polyurethane potting compounds and modified them with carbon nanotubes. The researchers also confirmed their technique retained the compounds’ elasticity, making them suitable for conformable electronics.
Performing a risk assessment for each component that needs potting resin will help determine the best options. Additionally, environmental tests are sometimes the best way to uncover weaknesses before electronics reach the market. These examinations could include exposing the parts to atmospheric humidity, vibrations and specific chemicals.
Learn about emerging options
As people research potting resin for electronics, they’ll soon see manufacturers continually launch new offerings to cater to current and potential customers. Intertronics launched epoxy-resin potting kits with the product in cartridges for easy application.
Ben Swanson, company sales manager, explained, “We recognize that every customer and every application is different. Not only do different applications require different materials and equipment, but the way a material is packaged can make an impact on the process and change its suitability for an application.”
Potting resins are also available that cater to people trying to make more environmentally friendly purchasing decisions. Buying sustainable products helps protect the planet’s future. However, there are numerous ways to do so. For example, many companies have bio-potting resins with plant-based ingredients. One recently introduced product has 31.67% bio content and protects electronics against issues such as mold and moisture.
An alternative that arrived on the market a short while ago is a plant-based resin with 63.33% biomaterials. The range highlighted in these two examples shows how people should shop around if they’re seriously considering potting resins in this category.
When purchasing potting resin for electronics, people may also need options that do not make drinking water unsafe. A two-part polyurethane potting resin underwent rigorous testing. The results confirmed it was a safe choice for electronics used in water treatment and similar applications. More specifically, the potting resin did not introduce contaminants, change the water’s smell or taste, or harm cellular and aquatic organisms.
Know that potting resins for electronics require different curing conditions
Letting potting resin cure in the appropriate environment is arguably as important as selecting the compound. The temperature where curing happens affects the speed and development of that process. However, factors unrelated to the resin itself — such as the depth and surface area of the application — can also influence overall curing times. Thus, the manufacturer data about cure timeframes is often a helpful guide, but designers should always consider the specific factors associated with the nature of the application.
If time is a significant concern or electronics professionals must cure a large group of components simultaneously, ultraviolet curing systems are excellent solutions. They can make curing finish in seconds. However, this approach requires specialized equipment, so it’s probably not the best solution for manufacturers who deal in lower volumes or are not ready to make significant investments to improve their curing process. Alternatively, people can mix additives into epoxy resins to speed up the curing process.
People must also be aware that some potting resins give off heat as they cure. That’s another consideration to be mindful of, particularly if working with heat-sensitive components. Silicones usually have the lowest heat levels of resins discussed here, making them well worth a look when high temperatures could cause issues.
Selecting potting resin for electronics requires following a careful process
This article breaks down some of the primary factors designers must consider when choosing potting resin for electronics applications. However, success requires evaluating any specifics associated with particular parts and the conditions they’ll likely encounter during use.
Additionally, electronics manufacturers may get feedback from customers about abnormal product functionality stemming from the likely failure of potting resins. Keeping the details of what happened is a practical way to avoid similar future pitfalls.
Emily Newton is a technical writer and Editor-in-Chief of Revolutionized. She researches and writes about how technology is changing the industrial sector.