Conformal coating and potting that stay put on rugged defense electronics
Industry: Defense electronics: radar, communication, navigation, and control systems
Technology: Vacuum plasma (VacuTEC), atmospheric plasma (PlasmaTEC-X)
On rugged electronics, a conformal coating or potting compound that lifts from the board is often found only after thermal cycling or humidity exposure, when the unit is already built. The cause is usually the surface underneath. Vacuum plasma cleans and activates the complete assembly, including the areas under components, so the protection bonds where it is supposed to.
The challenge
Electronics in defense systems must work in humidity, salt fog, dust, vibration, and wide temperature swings. Conformal coatings and potting compounds are the first line of protection, but they only protect as long as they adhere.
A populated circuit board is one of the most mixed surfaces in manufacturing. Solder mask, component bodies in different plastics, metal leads, connectors, and labels all sit side by side. On top come flux residues, release agents from component molding and contamination from handling.
The result is a coating that dewets during application, or one that looks fine at inspection but delaminates later. Where the coating lifts, moisture collects, and corrosion or electrical leakage can follow. In potted modules, a compound that pulls away from the housing wall leaves a path straight to the electronics.
Why conventional preparation falls short
- Washing processes remove some residues but add drying steps, chemistry control, and the risk of trapping liquid under low-standoff components.
- Manual wiping cannot reach under components and is impossible to repeat exactly.
- Adhesion promoters add materials that must be qualified, stored and applied consistently.
- Problems appear late. Adhesion issues typically show up in environmental testing or in the field, not at the coating station.
The solution
In a vacuum plasma chamber, the process gas reaches every exposed surface of the assembly, including gaps and the areas beneath components. The plasma removes thin organic contamination and activates the surface, so the coating or potting compound wets evenly and bonds chemically.
The process is dry and runs at low temperature, so there is no liquid to trap and no drying step. Each batch is treated with the same stored recipe, which makes the result repeatable and easy to document.
For potted modules, the inside of the housing can be treated as well. Larger housings or continuous flows can use atmospheric plasma inline, right before the potting station.
How it fits into production
- Trials on real assemblies. Customer boards and housings are treated in Tantec’s laboratory, and the process parameters are tuned to the materials and components involved.
- Recipe definition. Gas, power, and treatment time are locked into a recipe for each product family.
- Batch or inline integration. A VacuTEC chamber with fixtures for the customer’s boards sits before the coating line, or an atmospheric PlasmaTEC-X unit is placed inline for housings.
- Verification. Surface energy is checked during setup and as routine control, alongside the customer’s own adhesion and environmental testing.
Why Tantec
- Vacuum plasma designed and built in-house, with chamber sizes from laboratory scale to production and custom fixtures for the customer’s parts.
- Atmospheric plasma for housings and inline steps, so the full assembly process can be covered by one supplier.
- Laboratory testing on the customer’s own assemblies before any investment.
- A dry, recipe-controlled process that removes chemical handling and supports documentation.
- Decades of surface treatment experience across electronics, medical devices, and defense.
Is this your challenge?
If your coatings dewet, your potting pulls away from the housing or your units fail environmental testing on adhesion, send us a few assemblies. We will treat them in our laboratory and help you find the root cause at the surface.