Hermetic Sealing Technology


Read about news, technical breakthroughs and design best practices related to hermetically sealed wire feedthroughs and hermetic connectors.

New Cryogenic Feedthrough Improves Ease-of-Use

Epoxy-based hermetic feedthroughs have worked well in cryogenic systems for years. But the design modifications needed to operate in these extremely cold temperatures increased the size of the feedthrough and limited your mounting options. We recently eliminated these issues with an entirely new approach to cryogenic feedthrough design.

Intended for use in space simulation, laboratory and liquefied natural gas systems (LNG), our new cryogenic feedthroughs do away with a bulky compression system found on previous designs. Our new design also supports all the common feedthrough mounting styles—including threaded, welded, bolted or vacuum conflat.

In our new white paper, we’ll take a closer look at this cryogenic feedthrough technology and some design strategies such as:

Cryogenic Feedthrough
  • Overcoming coefficient of thermal expansion issues.
  • Finite element analysis (FEA) simulations to optimize the design of the epoxy-metal interface.
  • True hermetic performance in challenging conditions.
  • Easy implementation in a variety of cryogenic systems.

 

Download The White Paper

 

Hermetic Feedthroughs Safeguard Mission-Critical Electronics

Many mission-critical electronic devices have to be hermetically sealed to protect them against the ever-present threat of moisture damage.

Sealed electronics cavities are common in many military and defense applications, including missile guidance systems. In the civilian world, sealed electronics play an important role in laser systems, commercial avionics units, high voltage power networks, underwater pumps and automotive lithium battery packs.

Sealed Electronics Cavity

In our latest white paper, we’ll examine the ways moisture can make its way into a sealed electronics cavity. You’ll also learn how the right type of hermetic feedthrough can keep moisture out of an electronics cavity while allowing power and signal conductors to enter.

 

Get The White Paper Now

 

New Energy-Efficient System Eliminates Downtime

Douglas Electrical Plant

 

To reduce the risk that electrical outages will cause production delays that affect our customers, we recently invested more than $500,000 in a new combined heat and power (CHP) generator for our 30,000 square foot manufacturing facility. This system works in conjunction with our existing roof-mounted solar panels, which were installed in 2012.

The CHP system efficiently generates power on-site, while also recovering wasted heat energy for use in both heating and cooling the building. It delivers about 75 kilowatts of energy, while the solar panels kick in as much as 50 kilowatts of off-grid power.

The new system has three key benefits:

Reduces downtime risk. In the past, our facility experienced between 7 and 10 days of downtime each year because of unreliable power delivery. Following an extended period of downtime after Hurricane Sandy, we decided it was time to implement a system that would protect our customers from any electricity-related production delays. Having such a system in place is crucial since we maintain just-in-time manufacturing and delivery schedules for most of our orders.

Improves energy efficiency.   Thanks to our state-of-the-art onsite power generation system, we’ve now reached an 80 percent efficiency on our use of natural gas.  That’s a huge improvement over traditional heating and cooling systems, which typically combine offsite power generation with onsite boilers. According to the U.S. Environmental Protection Agency,  these traditional systems are 45% efficient at best.  The efficiency we’ve achieved with CHP and solar allows us to operate at net zero energy usage during certain periods of the peak solar months.  

Helps the environment. The new CHP and solar system also helps us play our part in protecting the environment, which is important to us and our customers. The system substantially reduces our carbon footprint and supports our ISO 14001:2015 environmental management initiatives.

Back-potting Standard Connectors

Can you use standard off-the-shelf electrical connectors in hermetically sealed feedthroughs? Thanks to an epoxy backpotting process that we’ve pioneered, the answer is yes.

Our proprietary backpotting process works with nearly any standard non-hermetic connector—including MIL-spec, D-Sub, circular, coaxial and more. Once back-potted, these connectors can offer hermetic performance at pressures up to 15,000 psi or vacuum to 1x10–10 Torr.

The technology used to seal third-party connectors borrows from our proven line of Potcon® hermetic feedthroughs, which also support a wide variety of connector types. But there are many good engineering reasons to stick with off-the-shelf connectors that do not offer hermetic performance. These reasons include:

  • Freedom of choice. Starting with a non-hermetic connector may allow you to use plastic or plated steel connectors if they meet the application requirements, saving cost and potentially weight. Standard connectors also give you many insert configurations to choose from, so you can pick exactly the right one for the job.

  • Function integration. Non-hermetic connectors can allow you to incorporate signal conditioning elements such as fuses or filters. You may also be able to integrate some of the wire harnessing elements.

  • Reduced lead times. Non-hermetic connectors usually ship from stock, eliminating lead time delays that can occur with some custom hermetic connectors.

Take all these engineering benefits into account, and you will often find that an off-the-shelf connector can save money, even after you’ve factored in our backpotting process.

Backpotted Assemblies

From cost and design standpoints, backpotting often makes the most sense when the off-the-shelf connector is part of a more complex feedthrough that has functional requirements beyond sealing.

In one recent job, for example, we combined a standard 32-pin round connector with a PCB that processes signals for a battery management system. We make feedthroughs like this every day using our CircuitSeal™ technology, but this particular design did require some extra attention because it operates in an inert gas environment. Because the dielectric constant of the inert gas environment is about three times lower than air, the potential for electrical arcing rises dramatically.

So we created a design that uses different layers of epoxy potting to address sealing and electrical isolation requirements. One layer hermetically seals the 32-pin connector. And the other layer provides electrical isolation between adjacent pins as well as between the pins and surface mounted components.

Delivering both the electrical and hermetic performance required careful formulation of the epoxy—which had to strike a delicate balance between electrical, mechanical and flow properties. And the complexity of this electrically-isolating feedthrough design involved the development of a new manufacturing process. But the results paid off. This feedthrough assembly meets the hermetic performance requirements of 1x10-8 cm3 He/sec while readily withstanding voltages as high as 2700 Vdc.

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