RFI Shielding Solutions for Plastic Enclosures

For electrical and RF engineers, RFI is the radio-frequency portion of EMI — roughly 30 MHz and up, where cellular, Wi-Fi, radar, and high-speed digital clocks live. Deep Coat shields it by depositing a continuous conductive film on the inside of a molded or thermoformed housing, so the part itself contains the RF energy.

How Vacuum-Metallized RFI Shielding Works

Metal is vapor-deposited inside a vacuum chamber, forming a conductive film that follows the part’s three-dimensional geometry across every surface exposed to the evaporant. The layer reflects, absorbs, and dissipates RF energy, attenuating the noise and giving the shielding effectiveness you specify.

• Continuous coverage — the film conforms to ribs, curves, and recesses, minimizing the gaps that leak RF noise.
• Defined grounding — custom masking keeps metal off the areas your design needs bare for continuity to chassis or the PCB ground plane, while preventing deposition on surfaces that would create a short.
• Selective shielding — shield only what needs it; keep connectors, windows, and antenna zones clear.

Metals We Deposit

Copper offers the highest conductivity for broadband RF (aside from silver, which is often cost-prohibitive); aluminum balances conductivity and cost at volume and provides an environmental barrier for the copper; nickel adds low-frequency shielding and an environmental barrier; nichrome adds the same benefits as nickel plus corrosion resistance and durability; and stainless steel offers similar benefits to nichrome. The patented Quad-Fire process can layer up to four metals in one draw — combining a high-conductivity shield with a durable, groundable surface in a single part.

• Metals: copper, aluminum, nickel, tin, nichrome, stainless steel
• Process: Quad-Fire (up to 4 layers) · Dual-Fire (up to 2) · 8 metallizing chambers
• Standards: engineered to support MIL-STD-461 / IEEE 299 targets (validated by your accredited lab)
• Best fit: telecom, defense communications, medical, and industrial RF electronics

One Vendor for the Whole Shielded Part

Because Deep Coat Industries thermoforms, masks, metallizes, and finishes in-house, the same partner that controls the housing geometry also engineers and applies its shield — keeping RFI performance repeatable from prototype to production, under an ISO 9001:2015 quality system.

Frequently Asked Questions

What is the difference between EMI and RFI shielding?

RFI is the radio-frequency portion of the broader EMI spectrum, typically from about 30 MHz upward. RFI shielding is EMI shielding tuned for those higher RF bands, where seams, apertures, and grounding are especially critical.

Can you shield a plastic enclosure without a metal box?

Yes. Vacuum metallizing the interior of a plastic or composite housing deposits a continuous conductive layer that turns the part itself into a Faraday cage — no separate metal enclosure required.

Which metal is best for RFI shielding?

Copper offers the highest conductivity for broadband RF (aside from silver, which is often cost-prohibitive); aluminum balances performance and cost at volume and provides an environmental barrier for the copper; nickel adds low-frequency shielding; nichrome adds corrosion resistance and durability; and stainless steel offers similar benefits. Quad-Fire can layer metals so one part gets both high conductivity and a durable, groundable surface.

Does the coating need to be grounded?

For effective RFI shielding, the conductive layer should contact the chassis or the PCB ground plane. Custom masking keeps metal off the areas your design needs bare for that connection.