Comparing Conformal Coating vs. Potting/Encapsulation

In today’s dynamic electronics landscape, manufacturers face a dual challenge. They must meet the demands for smaller, more powerful devices while ensuring the ruggedization and durability of components in challenging conditions. This is particularly true for printed circuit board assemblies (PCBAs) used in industrial, machining and control applications. These critical components often encounter harsh environments, including chemical exposure, dust, electromagnetic interference and physical shocks.

At RiverSide Integrated Solutions (RIS), we understand the paramount importance of ruggedization in PCBAs. Our multi-system approach allows us to tailor the degree of ruggedization to each product’s unique needs, providing a precise level of protection where it matters most.

In this article, we’ll explore the various degrees of ruggedization, from conformal coating to potting and more, that can transform standard PCBAs into resilient mechanisms ready to thrive in the toughest conditions.

Additionally, we’ll delve into advanced techniques, such as 3D printing and low-pressure molding. By the end, you’ll understand why RIS stands as a pioneer in automating PCB assembly while prioritizing ruggedness.

Among our capabilities are:

• Special Application Equipment (Robotic dispensing systems)
• Conformal coating (Silicone, Urethane)
• Potting (Epoxy, Polyurethane, and Silicone)
• Low-pressure molding technology
• 3D Printing

Most PCBAs can benefit from some degree of ruggedization. Imagine the intended application and all the steps the board will go through. From shipment to unboxing, assembly and connection, the opportunities are endless!

Considering all of that, it may make sense to opt for at least basic protection against moisture intrusion. A spray-on silicone conformal coating on both sides of the board usually provides this. The result is a very thin waterproof layer that fills in the gaps between the board and components. Doing this dramatically reduces the probability of moisture intrusion and corrosion.

Conformal coating is one of the most straightforward protections to apply while affording a much-improved protection against the elements.

RIS offers both silicone and urethane encapsulation for PCBs that we manufacture. We use a weight monitoring system to ensure the correct dispensation of the encapsulant. This ensures efficiency and accuracy.

The most common adhesives used for encapsulation are silicone or acrylic. These materials can be heat-cured or even UV-cured and are stable and inert.

Suppose we take the step up from an encapsulant to potting. In that case, this usually implies a large area up to and including the whole board. Potting generally aims to seal the electronics against extremes of exposure completely.

In an agricultural application, for example, the equipment could be used in the hot sun all day. It is also more likely to be exposed to dust and chemicals. At the end of the day, it may undergo a high-pressure washdown.

This would be a typical use case for a potted board. Marine use also commonly requires potted PCBAs due to continuous exposure to wet environments.

Potting compounds are often two-part epoxies that may undergo a heat cure.

So far, we’ve introduced conformal coating, encapsulation and potting. All of these are done with various silicones or epoxies to add degrees of ruggedness to electronic boards.

Some PCBAs have hybrid connections (both solder and wire bond). Protecting the wire bonds in those cases is important since they can be very fragile. The most common approach to ruggedization is to use silicone as an encapsulant. This stabilizes the bonds and reduces any stresses between the chip and the bonding posts.

A unique capability we offer at RIS is using a hot-melt extruded filament under robotic control. This is a lot like a 3D printer. We utilize this precision technique to add vibration and shock resistance to specific areas of the board.

One final element worth mentioning, though it is related to ruggedness in a more peripheral way, is 3D-printed tooling. Often, board space is at a premium. The solution is to place components as close together as possible but without interference.

Only a few contract manufacturers have committed to automate PCB assembly for delivery as RiverSide has.

RIS has thoughtfully added automation, inspection and manufacturing controls to our processes, where they will have the greatest impact. This benefits the quality of the product and improves yields. We also have the experience to advise your design team when some ruggedizing will benefit your designs.