RF Gasket and Absorber Dispensing

Custom EMI FIP Shielding and Dispensed Absorber
10MHz to 100 GHz : 100dB+ shielding

Introducing our premium custom RF and microwave enclosures, designed to deliver superior electromagnetic isolation and unmatched RF performance.

Meticulously machined and plated with high-loss tangent nickel, our enclosures provide exceptional suppression of electromagnetic interference (EMI) and resonance.

The internal surfaces are precision-roughened to optimize isolation, while the external surfaces remain sleek and professional. Enhanced with our industry-leading isolation gasket and advanced microwave absorber, each enclosure offers best-in-class, repeatable shielding effectiveness.

Whether you need high-volume production or a single prototype, our scalable solutions are crafted to meet the rigorous standards of RF-sensitive applications over the frequency range 10MHz to 100GHz.

case study

Detailed Description

Our RF and microwave enclosures are fully customizable, with precision machining and plating processes that leverage a high-loss tangent nickel alloy for superior performance. The enclosures feature roughened internal surfaces engineered to maximise RF isolation by reducing internal coupling, while the outer surfaces are polished smooth for a clean, professional appearance.

For optimal performance, we offer an optional integration of either our high-performance isolation gasket or/and advanced microwave absorber, each developed to deliver unparalleled RF shielding and reliability. Our isolation gasket is a form-in-place, silicone elastomer containing silver and nickel-plated graphite particles. When precisely CNC-applied, it provides intricate, highly effective gasket sections that achieve up to 120 dB isolation and ensure reliable, repeatable results across a wide range of applications. Unlike conventional shielding, our gaskets enable easy assembly, reusability, and stable performance in both high- and low-volume runs.

Our advanced microwave absorber is chemically bonded to the roughened metal surfaces, ensuring full cavity resonance suppression without the need for adhesives, which can compromise performance. Unlike traditional absorbers that require labour-intensive waterjet cutting and adhesive application, our absorber is designed for ultra-wideband performance and can be dispensed automatically with precise thickness control down to 0.1 mm. This ensures close proximity to circuits and components, allowing for maximized EMI suppression and consistent shielding integrity, regardless of production scale. We chemically bond to the roughened metal for maximum performance (10dB improvement on adhesive or epoxy methods).

Telecommunications Equipment
Automotive Electronics
Medical Equipment
Military and Aerospace Equipment
Quantum Computing
Consumer Electronics
Industrial Automation and Robotics
Test and Measurement Equipment
Space and Defence (outgassing tested)

Obtain Repeatable RF Results
Cavity Resonance Suppression
Effective 10 MHz to 100 GHz
Wideband operation
Pack RF circuits tightly
Highly accurate absorber and gasket placement (50um)
Very narrow walls (0.8mm)
Customizable absorber thickness per cavity basis
Temperature Stable
Low Cost and Quick Turnaround

Performance

Our RF and microwave enclosures are engineered to deliver unmatched performance in high-frequency applications. By utilizing ultra-high loss nickel plating on roughened internal surfaces, we achieve exceptional isolation and minimize internal coupling, ensuring signal integrity across all channels.

The combination of our Form-in-Place isolation gaskets and advanced microwave absorber materials provides industry-leading EMI suppression, with isolation levels reaching 80 to 120 dB.

Our absorber technology is designed for ultra-wideband performance and is chemically bonded for seamless coverage, eliminating gaps and maximizing cavity resonance suppression. This high-performance shielding solution ensures repeatable, reliable RF performance, even in demanding environments, making it ideal for applications that require precision and robust electromagnetic isolation.

We are able to effectively screen connectors by printing shielding gasket on walls and curved surfaces.

A test fixture was made consisting of a coupled line in a small cavity (20mm). A measurement was made with and without absorber. It can be seen that cavity resonance suppression is achieved within small cavities showing the effectiveness of the material.

Design Rules

When designing enclosures for our custom RF shielding and microwave isolation solutions, it’s essential to follow specific design rules to ensure optimal performance.

Gasket Guidelines
To prevent interference between sensitive circuits, it’s recommended to partition areas within the enclosure and encircle each with a grounded ring. This ground ring should be via-stamped to inhibit internal propagation modes, with a minimum width of 0.25 mm on each side beyond the Form-In-Place (FIP) dispensing bead. Use compression stops to limit gasket compression, preventing over-squashing. Compression stops should be positioned near screw fixing holes, which should be distributed evenly across the PCB. Gasket beads can range from 0.8 mm to 3 mm in diameter, with the compression stops set to achieve approximately 30% compression. For RF traces on the top layer that need to exit the cavity, we can add “mouse holes” in the gasket to avoid shorting. Additionally, the exposed ground ring should be free of solder resist to ensure complete grounding.

Absorber Guidelines
For optimal absorber performance, design cavities to allow unobstructed coverage, maintaining a minimum clearance of 0.2 mm from circuits. All interfaces should be smooth and free from irregularities to support efficient gasket application and prevent gaps. We can tailor the absorber thickness as required, typically advising it to be dispensed approximately 0.3 mm from the tallest component within each cavity. The thicker the absorber layer the lower in frequency it works, so generally we advise go for the thickest layer that the design facilitates. Just a small amount in contact with the cavity lid is generally enough to supress most problems.

Following these guidelines will help users maximize the effectiveness of our gaskets and absorbers, resulting in consistent, high-quality shielding for RF and microwave applications.

Custom Designed and Machined housings. We supply CNC as well as the gasket and absorber.
Compact and lightweight
Portable and rugged
Long Lifetime
Low Outgassing – suitable for Space Flight.
Temperature range -55C to +200C

Printing around connectors for maximum shielding

Technical Specifications

Material Properties – FIP Gasket

We can offer a range of materials for the FIP gasket. Our most common is a Nickel coated graphite with a trace of silver.
However, the full range is shown:

EECL-SA001 Silver plated aluminium filled silicone (good galvanic compatibility with aluminium alloy components).
EECL-SA001(Black) Silver plated aluminium filled silicone (good galvanic compatibility with aluminium alloy components.
EECL-SA002 Silver plated aluminium filled silicone (higher performance silicone RTV base than SA-001).
EECL-SC001 Silver plated copper filled silicone (high temperature resistant version).
EECL-SC002 Silver plated copper filled silicone (low force deflection version suitable for thin wall mouldings).
EECL-SN001 Silver plated nickel filled silicone (good long-term stability / high temperature performance).
EECL-SN002 Silver plated nickel filled silicone (higher performance silicone RTV base than SN-001).
EECL-NC001 Nickel coated graphite filled silicone (good electrical performance – particularly on surfaces with high contact resistance e.g. stainless steel, die cast zinc). This is our standard and recommended process. The properties are below, get in touch for the properties of the other materials.

Cured Properties
Density	2.5gcm-3
Hardness	50 Shore A
Volume Resistivity	<0.1Ω.cm
Adhesion	>50 Ncm-2
Attenuation – 100MHz to 10GHz (MIL-STD 285)	85 – 110dB (typically)
Compression Recommended (allowable range)	25% (10 – 50%)
Gasket Resistance	<0.5Ω.cm
Elongation	100%
Compression Set – 70 hours at 23°c	<20%
Service Temperature Range	-55°c to 150°c
Force Deflection – 0.7mm high gasket section	2.8Ncm-1 @ 10%
	7.4Ncm-1 @ 25%
	26.4Ncm-1 @ 50%

EECL Gasket and Absorber Technology

CASE STUDY

To address critical isolation and resonance issues in a high-performance beam former, our EECL gasket and absorber technologies were applied with exceptional results. The beam former contained 32 high-gain amplifiers on a single card, each delivering 40 dB of channel gain. However, significant channel-to-channel leakage and cavity resonance issues rendered the card nearly unusable. Temperature fluctuations further caused unbalanced attenuator performance and inconsistent gain settings.

By incorporating the EECL gasket and precision-engineered RAM absorber into the enclosure, channel isolation improved dramatically, achieving stable, repeatable performance with consistent gain and flatness across all channels. The innovative shielding approach eliminated unwanted coupling, while our automated, high-precision manufacturing process enabled rapid production of hundreds of consistent, high-quality cases.

The final card, equipped with our custom gasket and absorber, now demonstrates outstanding performance and isolation, as shown in the image below.

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