Printed circuit boards (PCBs) contain an electronic device’s most critical components. To protect these components from damage, electronics engineers use two main methods: PCB potting and conformal coating.
Both PCB potting and conformal coating use organic polymers to protect PCBs and their associated electronic components. What are the similarities and differences between these methods, and which one is right for your electronics application? To get started, let’s find out how each technique works.
PCB potting is a method used to protect circuit boards (referred to in these contexts as the substrate) by filling a PCB enclosure with a liquid material called a potting compound or encapsulation resin. The potting compound fills the device’s housing and, in most cases, covers the entire circuit board and its components, although in some cases it can be used to pot individual components.
Potting provides excellent abrasion resistance, as well as protection against heat, chemicals, impacts and other environmental hazards. Typical potting compound materials include epoxy, polyurethane and silicone compounds.
Here’s a quick comparison of the most common PCB potting materials:
Conformal coating is another method of protecting PCBs that coats the substrate with a thin layer of polymeric film or another non-conductive material. A conformal coating is typically only 25 to 250 microns, making it a much lighter option than PCB potting that takes up much less space. It provides excellent protection against hazards such as corrosion and particulate matter, and conformal coating waterproofing also helps protect against moisture.
Many different conformal coating materials are available. Typical options come from a relatively similar range of materials as PCB potting, including epoxy and silicone compounds, as well as other options such as acrylic and a sustainable solvent-free polymer called parylene.
Common application methods include various types of aerosol spraying, ranging from a handheld, human-operated spray gun for the most sensitive applications to a fully automated selective coating process when speed is a priority. Dip coating is also a widely used and cost-effective alternative for applications that require minimal masking of components.
Each conformal coating process and material brings its own advantages and challenges to different applications:
Whatever coating you choose, make sure you’re familiar with the IPC conformal coating standards that establish industry best practices for conformal coating.
Now that we’re familiar with the basics of PCB potting and conformal coating, it’s time to ask: Which is the superior PCB protection solution? The answer, as you might suspect, depends on the application for which you’re using these technologies.
Both PCB potting and conformal coating will help protect your substrate from small impacts, corrosion, vibration, moisture and other common hazards. Below, however, are some key areas in which PCB potting and conformal coating differ. Consider these points when choosing which option is best for your application:
Most of Polycase’s enclosure models are designed to accommodate PCBs in some form. We offer both potting boxes and general use enclosures that are created for great performance when mounting and insulating PCBs.
Polycase’s potting boxes are ideal choices for devices that require PCB potting. Our TX Series potting boxes are among our most popular and cost-effective potting box options. They are made from durable black ABS plastic and are available with optional mounting flanges and optional glue-on covers.
If you’re using conformal coating rather than PCB potting, consider our enclosure models with built-in PCB mounting capabilities. We offer models like the Polycase EX Series that are designed to allow a PCB to slide in easily. Many of our enclosure models also include PCB mounting bosses that make it simple to securely mount a PCB inside.
Polycase 2420TX Potting Case
Not sure which kind of potting box your project requires? Need advice on how to mount a PCB in your enclosure? Polycase’s experts can help with all kinds of questions related to electronics enclosures and PCBs. Call us at 1-800-248-1233 or contact us online for more information.