Potting: Electronics Encapsulation

In some cases, electronic components need protection from environmental factors like humidity, corrosion, contaminants, and structural threats. Potting (encapsulation), is one way of achieving that protection.Encapsulation

 

So what exactly is Potting? How and when is it used? Who does it?

Here’s the big idea

From restaurants to war zones, electronics require special protection from the elements so that they can function reliably. Delicate wires and connections are threatened by not only weather, contamination, and physical abuse, but also other electrical currents nearby. One way to protect those electronics is through Encapsulating the part in a “plastic” that can shield, insulate, and absorb impact.  We like to call it potting.

It’s not always plastic.

We say plastic for simplicity’s sake, but in reality, the world of potting compounds the possibilities are pretty broad.  Materials such as (but not limited to) liquid plastics, polymers, epoxies, urethanes, and rubber are utilized based on factors like price, curing time, application, life expectancy, size, mold, etc.

Mold. Or maybe not.

Potting Mold  |  Ehren-Haus

In many cased, a mold is made and the potting compound is poured into said mold, directly over the electronic components, for curing. There are cases, however, when the compound can be sprayed directly on the part. Again, this depends on the factors listed above.

Curing

Curing is the time it takes for the potting compound to completely harden to its functional state. Curing times are incredibly important.  They vary greatly between materials.  We learned this first hand during one of our first electronics jobs. We decided to run some preliminary tests to get baseline readings before the potting was completely finished curing. Much to our dismay, the part tested below our expectation. We gave it the full amount of time necessary, tested again, and BINGO it tested off the charts.  So what happened? Just like when you’re baking, just because something looks “done” on the outside, doesn’t mean it’s “done” on the inside. Curing times are a delicate science and should be followed as such.

Craftsmanship, experience, expertise and potting

Unlike baking, electronics encapsulation is not simply a “follow the directions” type of process. From the very beginning of the process, understanding materials, molds, mold releasing agents, etc. requires a depth of knowledge and expertise that only comes with experience. Applying budgetary, application, time, and safety requirements to develop the best solution is not a simple task.

So who does potting and encapsulation?

We do. When we initially decided to add electrical engineering and manufacturing to our services, we were not planning to delve into the fickle world of potting. We saw the challenge it presented and assumed that we would be better off forming a relationship with an experienced supplier. Unfortunately, we weren’t able to find anyone that could offer us full service potting expertise.  Either they weren’t familiar with the quality standards we required, weren’t willing to work with the breadth of compounds we needed, or couldn’t get lead times to a reasonable point for us. With customers in need, we made the decision to bring on new, experienced staff, testing equipment, assembly facilities, etc. so that we could provide this for them completely in-house. It was a logistical and financial risk that has since paid off for us and our clients.

Don’t assume that every electronics manufacturer is a potting expert. Do some research and don’t be afraid to ask.  In my experience, most are up front and honest when a project is beyond their scope…but you may have to ask very specifically.

If I’ve sparked your interest and you want to chat with our engineers about potting, give me a call.  They love that kind of thing.

 

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