Designing With CircuitSeal—Part One

If you design electrical equipment or devices, you increasingly have to tackle three related engineering problems. Not only do you have to improve the performance of your electrical systems, but you also have to reduce their size and cost.  One technology that can help with all three problems is CircuitSeal™.



Using our proven epoxy formulations, CircuitSeal creates direct hermetic seals around flex, rigid, and hybrid circuit boards as well as flat flex cables (FFC).  The technology also allows you to incorporate passive electrical components into the sealed circuit assembly—such as filters, fuses and resistors.  And CircuitSeal complements our other epoxy-based hermetic sealing methods. For instance, you can combine CircuitSeal with back-potted connectors.  Or you can design hybrid hermetic seals that directly seal around both circuit boards and wires or other conductors.

Whenever you need your electrical systems to function reliably in pressurized, vacuum, moisture-prone or other kinds of harsh environments, CircuitSeal can play a role.  Typical applications include:  

  • Semiconductor manufacturing equipment
  • Instrumentation and control systems
  • Automotive control and sensing systems
  • Magnetic bearings systems, including compressors, turbo expanders, flywheels and turbines
  • Environmental and vacuum chambers, including thermovac, vacuum heat treat and HAST systems
  • Military weapon and transport systems
  • Sealed-off laser systems

Compared to traditional feedthroughs and connectorized wire harnesses, which are still more widespread, CircuitSeal offers some significant advantages:

  • Improved Performance.  With signal conductors running directly to the circuit board, CircuitSeal helps maintain signal integrity while eliminating any losses or electrical noise (EMI) related to connectors.  Directly sealing the circuit board also does away with potential failure points at the electrical connection.
  • Compact Size.  CircuitSeal doesn’t just remove the need for bulky connectors; it also saves space by facilitating high conductor densities and the integration of electrical components into one sealed assembly.   Depending on the application requirements, CircuitSeal assemblies are typically 30 to 70% smaller than a comparable connector-based solution.
  • Enhanced protection from outgassing.  A variety of sensors, switches, diodes and capacitors are increasingly being potted in epoxy as part of the CircuitSeal process.  Potting and hermetically sealing these passive components effectively blocks contamination due to outgassing, which benefits semiconductor and vacuum applications.
  • Cost Reduction.  By integrating some components and eliminating others, CircuitSeal can reduce cost substantially. The amount of the savings varies but generally increases with conductor count and production volumes.  For example, we've produced CircuitSeal assemblies with high conductor counts that cost 80% less than an equivalent connectorized wire harness.

In an upcoming series of blog posts, we’ll take a deeper dive into CircuitSeal’s technical capabilities and offer up some design tips that you can easily apply to your electrical assemblies.  Sign up below, and we’ll send you the new posts as they become available.

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Douglas Electrical
Address:    5 Middlebury Blvd.
Randolph, NJ 07869
Tel:    973.627.8230
Fax:   866.206.6916
General inquiries:
T 973.627-8230
Technical information:
T 973.627-8230

Engineered Hermetic Seals and Connectors for Wire and Cable

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