This podcast discusses Key Polymer’s Tough-Seal, a unique potting compound that protects electronics from vibration, moisture, and extreme temperatures. Unlike rigid compounds that crack, Tough-Seal’s flexibility forms a durable seal. It cures underwater, resists temperature swings, and may offer EMI shielding. Potting compounds like Tough-Seal can significantly improve electronics’ reliability, lifespan, and save costs by preventing failures.

John Maher: Hi, I’m John Maher. I’m here today with Melissa Mitchell, Product Manager and Senior Engineer at Key Polymer, a manufacturer of electronic potting compounds, adhesives, coatings, and other chemical compounds. Today we’re discussing the role of potting compounds in protecting your electronics. Welcome, Melissa.

Melissa Mitchell: Hi, John. Great to be here.

What is a Potting Compound?

John: Thanks. Yeah. You, too. So, Melissa, can you explain a little bit about just what a potting compound is, and maybe, provide some examples of some electronic failures that can be caused by environmental factors like moisture and vibration?

Melissa: Sure. So, potting compounds are liquid resins. So, for Key Polymer we have our Tough-Seal and Tough-Seal Ultra potting compounds. They are liquid resins that are used to fill, seal, and protect sensitive electronics. So, the liquid is poured into a housing with electronic components inside. Then as the material cures, it forms a protective barrier that will coat and protect the sensitive electronics to eliminate electronic failures.

Types of Electronics Potting Compounds are Used For

John: Are those electronics always circuit boards, or can they be any type of simple electronic switches and things like that?

Melissa: Yeah. So electronics, as you well know, probably, are everywhere. So, they’re found in never ending applications in our daily lives from lights to smartphones, automotive sensors. As customers, we rely on these items functioning without failure. So, don’t think about how sensitive electronics really are, but there’s a lot of things that can cause electronic failures.

What Causes Failures in Electronics?

John: Yeah. So, what are some of those things that can cause failures in electronics?

Melissa: Yeah. So, vibration and shock. Electronics contain printed circuit boards, components, cables, and they can all be damaged pretty significantly with vibration or impact or shock. So, you drop your cell phone, you definitely can damage some of the components inside. For sure. And, all of these special integral parts, solder joints and things like that, can pull and crack during any vibration or shock. Then, disrupt the electrical circuit. So, definitely a problem. For sure.

Potting Compounds Help to Keep Electronics Together

John: So, in that case, the potting compound is sort of keeping all of the parts together and making sure that nothing breaks off when it impacts something?

Melissa: Yeah. For sure. It kind of encapsulates everything and forms a protective barrier, if you would. So, Tough-Seal’s pretty unique from the standpoint of potting compound that is more elastomeric. So, it definitely absorbs the vibration and shock a little more than something that would be hard, like a hard hat or glass, or whatever.

John: Okay.

Melissa: So, definitely protective. For sure.

John: What are some other things that can cause failures in electronics?

Melissa: Yeah. So, moisture and water. So, moisture and water getting into electrical components. Humidity is a problem in a lot of applications and that water just penetrates right to the circuit itself. The electronic components can be damaged from corrosion that actually is caused from the water. It’ll directly damage the circuitry. Then, you’ll see failures from the electronic circuitry. So, definitely water and moisture, humidity, they’re all major problems with electronics.

John: Okay. What else?

Melissa: Thermal cycling and thermal shock. So, something that would go from hot to cold, back to hot, back to cold. Those changes in temperature, back and forth between hot and cold, can cause damage to electronics because it puts stress on all the solder joints. Any little components that are on the printed circuit board kind of can tug and pull at them and definitely result in some electronic failures. Dust and contaminants can also build up. So, dust can build up on the boards and cause excessive changes in the amount of heat in the board, which can cause damage and system failures to the electronics, as well.

And then, obviously people can physically tamper with electronics. So, a lot of companies would try to incorporate a potting compound in their design to pour over their electronics to protect their intellectual properties so that their competitors can’t see what they’ve done to make their project, or a part, or sensor. Whatever that is that they’re trying to develop, they want to protect that intellectual property so their design cannot be copied.

How Does Potting Compound Protect Electronics?

John: And then again, how does the potting compound itself help to protect the electronics from all of these different problems that you just mentioned?

Melissa: Yeah. So, you pour the potting compound over your components, or dispense the potting compound over your components. What it’s going to do is, it’s going to cure and form a barrier proof seal, almost like if you poured rubber to form a tire, it would definitely form a seal around the components and just seal the parts from being exposed to anything that we really talked about. Just gives a good layer of protection and again, hides the components from proprietary compromise.

Hidden Performance Benefits of Potting Compounds

John: Okay. Beyond just protection, are there any other hidden performance benefits to using potting compounds?

Melissa: Yeah. So, there are hidden performance benefits. For sure. Especially with Tough-Seal and Tough-Seal Ultra. Tough-Seal’s very unique because it is an elastomeric potting compound that is a hybrid epoxy. So, it ranges from different hardnesses from pencil eraser hard to car tire hardness. Most potting compounds that are epoxy and urethane based are usually harder, almost like hardhat hard. A lot of these hard potting compounds crack over time. Once you have a crack in a potting compound, then that’s where the moisture, the dirt, any contaminants, can get in. It’s not as protected from vibration and shock, and just also just leads to failures.

Tough-Seal Does Not Exotherm

Tough-Seal itself is pretty unique from the standpoint that it is non-cracking, like we talked about it. It doesn’t exotherm when it cures. So a lot of potting compounds, because they’re a two-part material, you mix them, they react, they go through an exothermic reaction. They give off a lot of heat.

So, when you have an excess amount of heat, it can cause larger amounts of heat to kind of flood the board. And, as the potting compound cools. You know? Once it’s cured, it will start to cool. That will cause stresses on the board, can tug on some components. So, heat with curing potting compounds can compromise the board itself.

Tough-Seal Does Not Shrink

Tough-Seal, also, doesn’t shrink. So, it’s pretty important from a shrinking standpoint because again, if a potting compound shrinks as it’s cooling, the shrinking can cause components to be tugged, solder joints to be broken. That would also result in failures in the electronic circuitry.

Tough-Seal can Dissipate Heat

Tough-Seal has some higher thermally conductive properties, so that can dissipate heat. If a board is going to generate heat, sometimes they’ll have to add a heat sink to something. Might not be as necessary if you have a thermally conductive potting compound.

EMI shielding… We don’t have any specific testing that we’ve done with our products. We are always very eager to provide samples to our customers. We have a lot of customers that if we don’t have the answer regarding some specific property or test that they’re looking for results for, we’ll provide samples so that customers can do their own testing.

Are Plotting Compounds Important for Dealing with Environmental Threats?

John: Okay. We’re in the midst of kind of global warming. We’re seeing more and more of these sort of extreme weather events that are happening. Are there any environmental threats like these weather events that make potting compounds even more critical now?

Melissa: Yeah. Definitely, the temperature changes where you could have something used in an extremely hot temperature, and then something that might see an extremely cold temperature. Those thermal cycling, or thermal shock, as they’re often referred to, they can certainly wreak havoc on circuitry, any potting electronics and sensors. So from that standpoint, the stability from some of these potting compounds that offer UV protection, thermal protection, they are all very important in ensuring that the electronics are protected, especially under those most aggressive conditions. For sure. Tough-Seal and Tough-Seal Ultra are known for that boost in properties. For sure.

Can Electronic Components Sealed with Tough-Seal be Submerged in Water?

John: Is it possible for Tough-Seal to completely seal an electronic component from water so that it could actually be submerged in water? Or, is it just more of a matter of if it gets rained on it would be okay?

Melissa: No. Great question, John. For sure. Because we do have some major underwater applications. We have underwater marine lighting. So, completely sealed so that things can be completely immersed in water. Underwater robotics are pretty common for Tough-Seal to be used in. The immersion in underwater is where we really do shine.

Something that’s pretty unique about Tough-Seal is it will actually cure underwater. So, if you were to pot or put some Tough-Seal in an application that’s immersed in water to begin with, you were to inject the material into the electronic area, you certainly would see the Tough-Seal cure underwater, which is pretty unique. For sure. It’s part of the beauty of Tough-Seal. For sure.

How Potting Compounds Affect Reliability

John: Can we quantify the value of using potting compounds for a company, in terms of increased reliability or lifespan or cost savings?

Melissa: Yeah. That’s a good question. For sure, John. To be honest, using potting compounds is actually valuable beyond estimation. For sure. To truly quantify the value, it’s difficult because it always varies from customer to customer. So, there’s always a different perspective from different customer view. But, potting compounds absolutely increase the reliability. So, that’s been confirmed through hours and hours of reliability testing, upward to 2,000 hour reliability tests that are run to just ensure that the product is going to perform as it’s supposed to. That increases the lifespan. Obviously, you ensure that things are going to last in the applications long-term.

If you suffer from a recall, that’s a pretty big hit for a company to have to withstand, definite failures in the field. So, that’s very, very critical. Those cost savings of not having to replace field failures is very critical. If you prepare using a potting compound, you don’t see those issues further down the road. You can save yourself, like I said, quite a bit of cost savings. You can’t really put a number on it.

Using Plotting Compounds to Protect Intellectual Property

John: Right. And then, in terms of the intellectual property, too, that’s inestimable, what you could potentially lose to a competitor if they’re able to copy your product, or something like that.

Melissa: Yeah. Absolutely. Tough-Seal, in its final form, it’s a thermostat, so that material is not removable. It’s completely in its place, an integral part of the whole part. So, definitely protecting the intellectual properties is important. For sure. Potting compound is a great way to do that.

Get More Information About Key Polymer

John: All right. Well, that’s really great information, Melissa. Thanks again for speaking with me today.

Melissa: Yeah. It was really great to be here. Thanks again, John.

John: And, for more information you can visit the Key Polymer website at, or call (978) 683-9411.