EMI Shield and Gaskets

Overview of EMC/RFI Issues

The phenomenon of electromagnetic interference (EMI) is familiar to virtually everyone, even if they do not understand the underlying principles. Most people have witnessed first-hand the effects of interference. To control EMI Government organizations, such as the FCC, CSA, and EEC, mandate that manufacturers may not design, produce, or sell electronic equipment that jams the public broadcast services. In other instances, however, EMI can constitute to more than a minor inconvenience. The military and medical communities, for example, require trouble-free operation of their electronic equipment in adverse electromagnetic environments since malfunctions could jeopardize mission, and potentially cause serious harm. The European Union’s EMC (Electromagnetic Compatibility) directive also mandates that “the apparatus has an adequate level of intrinsic immunity to electromagnetic disturbance to enable it to operate as intended”.

EMC Design of High Speed Systems

The trend in today’s electronic devices is faster, smaller, and digital rather than analogue. Most equipment (95%) of today contains digital circuits. Today’s digital designers must create a circuit board that has the lowest possible EMI, combined with the highest possible operating/processing speeds. Design of the printed circuit board (PCB) is the most critical EMC influencing factor for any system, since virtually all active devices are located on the circuit board. It is the changing electrical current produced by the active devices that result in EMI.

Design Approaches

There are two approaches that can be used to reduce the emission from the circuit board. The first approach is to operate the circuit at the slowest speeds consistent with the functionality of the system, lay out the PCB with the smallest possible loop areas (especially the high speed devices), insert suppression components such as filters, ferrite beads, and bypass capacitors into the circuit to reduce its bandwidth. These techniques will result in a desired decrease in the high frequency and the circuit bandwidth, and a corresponding undesired decrease in both the operating speed and system reliability. The use of slower speeds with reduced bandwidth will help to desensitize the circuit to external magnetic susceptibility fields. The second is to use shielding. Shielding is the only non-invasive suppression technique. Since the shielding is not inserted into the circuit, it does not affect the high frequency operating speed of the system, nor does it affect the operation of the system should changes be made to the design in the future. In addition, shielding does not create timing problems and waveform distortion; it does not decrease system reliability; and it reduces crosstalk. Plus, shielding works for both emission suppression as well as susceptibility problems. Even with the overall advantages of shielding, the most cost-effective approach is to use a combination of circuit suppression/hardening and shielding.

Product Information:

Fabric Over Foam

Soft Shielding with Durable Design

EMI suppression isn’t easy to achieve if a gasket doesn’t fit your application’s requirements. Our fabric-over-foam gaskets are ideal for applications that require low compression force but still need high conductivity and shielding attenuation. If you’re looking to protect computer, telecommunications, or other equipment that requires soft shielding, we provide fabric-over-foam gaskets in a variety of shapes and thickness to meet your needs.

Available in nickel/copper (Ni/Cu) and tin/copper (Sn/Cu), our fabric-over-foam gaskets deliver versatile galvanic compatibility and shielding.

Other benefits include:
  • Low compression forces throughout a compression range from 30 to 75 percent based on the shape of the fabric-over-foam gasket and its materials.
  • Shielding effectiveness of >100 dB across a spectrum of frequencies.
  • Gaskets that are UL 94 V-0 flame-retardant and halogen free (EcoGreen™) making Laird gaskets eco-friendly and exceed RoHS compliancy.
  • High abrasion and shear resistance due to metallized fabrics that incorporate proprietary coatings that do not degrade shielding performance.
  • Urethane, thermoplastic elastomer (TPE) and even silicone core material, which provide low compression and ensure long term reliability of gasket performance in a wide variety of applications.

  • For more information, visit the product page here

    SMD Grounding Contacts

    Laird’s SMD (Surface Mount Device) Grounding Contact is a foam cored contact with a metalized polyimide film outer covering. It is used for circuit grounding of SMT (Surface Mount Technology) devices. These contacts are designed to be solder reflow compatible and are suitable for automatic processing.


    For more information, visit the product page here

    Vent Panels

    Maximum Protection. Reliable Filtration.

    Air particles can infiltrate even the best EMI applications. But with the right components, we can help you keep your designs protected and dust-free. Laird’s Electro-Air EMI/Dust Filtration, MaxAir and Electrovent panels provide effective shielding while capturing airborne contaminants, so you can enjoy quality protection with minimal interference.

    If you’re looking for a proven air filtration and EMI shielding solution, we’ve got you covered. Our vent panels consist of layered, woven and crimped wire mesh combined with filtering media to help capture nature’s elements without disrupting ventilation and airflow to your applications. Each panel features EMI gaskets designed to prevent signal migration to sensitive electronic equipment.

    Our Vent Panels Provide:
  • Protection for universal applications—they can be used for small enclosures, large housings, high traffic areas and room-size facilities
  • An extensive service life that’s built to outlast the equipment it protects
  • A variety of design specifications—module construction is available in assorted standard sizes from 3 to 18 sq. in (19,35 to 111,13 sq. cm)
  • Easy installation through pre-drilled holes or captive fasteners that allow for quick mounting and removal
  • Design assistance—Laird’s engineering department will provide technical assistance and testing data to help you solve the toughest application challenges

  • For more information, visit the product page here

    Board Level Shielding

    Dynamic Shielding. Unwavering Protection.

    Managing electromagnetic interference requires protection that effectively considers space, weight and application constraints. Whether you need a one-piece, two-piece or a multi-compartmental shield, our board level shields provide isolation of board level components.

    Fashioned from Laird-manufactured parts, our versatile shielding solutions provide a strong foundation for your EMI applications without compromising the quality of base materials or design. Each board level shield offers a secure cover design that’s ideal for applications subject to shock and vibration such as mobile military vehicles, commercial aircraft and wireless electronics. Available in custom shapes and mounting options, our shields will help you minimize crosstalk and interference while maintaining optimal system speed and performance.

    Our shielding solutions also provide:
  • One-piece and two-piece designs featuring six sides of protection.
  • Multi-compartmental shields available to shield multiple components on a board
  • Proprietary process for 100% automatic optical inspection for measuring co-planarity.
  • Reliable protection from shock and vibration using secure locking features between the frame and cover.
  • Corner feature options include: folded, rigid corner, or full drawn to meet flatness and shielding effectiveness requirements.
  • Mounting features: SMT castellations (standard), thru-hole lock pins, or tabs.
  • A built-in feature in the frame for easy removal of the pick and place bridge for post reflow inspection.
  • Tape and reel packaging available for automated placement onto the PCB.
  • Two-piece designs can be supplied pre-assembled or unassembled.
  • Drawn board level shields available to address high-frequency leakage.
  • High-quality base materials such as CRS 1008/1010, Nickel Silver, Aluminum and Stainless Steel.

  • For more information, visit the product page here

    Finger Stock

    Laird offers an extensive selection of enclosure sheilding gaskets. Engineered metal Fingerstock solutions from Laird dates from 1938. Laird specializes in designing miniatureparts of thin strip metal in quantities ranging from thousands of pieces to millions of pieces. With over 3,400 standard parts, Laird has an off-the-shelf solution that meets your application’s requirements. Contact strips are used for grounding and shielding in high-frequency equipment and for forming large diameter contact rings.A wide variety of beryllium copper contact strips provides engineers anddesigners with flexibility in solving grounding and shielding problems. Various lengths, widths, thicknesses, contours and hole locations are possible for many of the standard catalog items.

    Engineered metal Fingerstock solutions from Laird dates from 1938. Laird specializes in designing miniature parts of thin strip metal in quantities ranging from thousands of pieces to millions of pieces. With over 3,400 standard parts, Laird probably already has an off-the-shelf solution that meets your application’s requirements.

    When custom designs are needed, Laird engineering staff helps construct efficiencies in performance, cost and manufacturability from the very beginning stages of the application.

    Laird specialized capabilities:

  • Assembly
  • Heat staking (both hand and automatic)
  • Heat treating
  • In-house die and fixture manufacturing
  • Multislide equipment
  • Photoetching
  • Plating
  • Progressive die stamping
  • Prototype fabrication
  • Resistance welding
  • Riveting
  • Secondary fabrication
  • Wire EDM

  • Laird’s standard precision electronic contacts ground, carry current and signals, and interconnect boards and devices. A wide variety of plating options allow for the maximum electrical current carrying performance. An array of designs in a standard format are ready for production. Installed costs are lower with our tape and reel.


    For information on Enclosure Shielding Gaskets & Contact Strips, visit the product page here Or for information on Metal Connector Shields, visit this product page here

    Wire Mesh and Knitted Gaskets

    Knitted Wire or Conductive Thread gaskets and tape for shielding and grounding of electronic and electric applications.

    All Mesh EMI Gasketing has been designed to offer the highest possible levels of attenuation. Knit construction enhances long lasting resiliency, making it an ideal material for highly sensitive components in permanent or semi-permanent enclosures where environmental sealing is not a concern.

    FEATURES:

  • Highest attenuation characteristics
  • Available in beryllium copper, Monel®, tin plated copper clad steel, aluminium and stainless steel
  • Versatile mounting
  • Consistent point-to-point contact for high shielding effectiveness over life of gasket

  • For more information, visit the product page here

    Conductive Foam Gaskets


    Laird’s Ecofoam™ offers an innovative approach to traditional shielding and grounding by providing X, Y and Z-axis conductivity, enhancing the shielding effectiveness required to meet the increasing microprocessor speeds of today’s computer, telecommunications and other electronic equipment. The product is offered with a conductive PSA tape on one side.

    Ecofoam™ can be customized to your application by die-cutting, hole-punching, notching, and so on and is especially useful for odd-shaped applications which are difficult to shield with typical profile gaskets. Ecofoam™ is designed for low-cycling applications such as input/output (I/O) shielding and other non-shear standard connectors.

    For more information, visit the product page here

    Form-in-Place Gaskets & Sealer

    Molded for Performance

    Laird manufactures form-in-place gaskets using an automated system for dispensing conductive elastomers. Our resilient, form-in-place gaskets provide reliable protection for compartmentalized cast or plastic enclosures and packaged electronic assembles.

    If you’re looking for EMI components that are compatible with plastic, metal and plated substrates, our form-in-place gaskets can assist. Laird manufactures standard and custom form-in-place gaskets that optimize performance for a variety of electronics including telecom antenna(Radio/RRU/AAU/AAS), automotive(Cluster/infotainment chassis sheilding/Radar/Autonomous driving system), datacom(optical transceiver/ high speed connectors).

    Benefits of Our Form-in-Place Gaskets:
  • A total cost savings in the form of reduced raw materials, labor or assembly line
  • Room temperature cure gasketing materials that eliminate the need for costly heat curing systems
  • Easy-to-program operating system that permits quick tooling and prototype development within 24-48 hours
  • High shielding effectiveness: 85-100 dB up to 10 GHz
  • Excellent adhesion to a wide variety of metal and plastic substrates such as aluminum/casting alloys and stainless steel

  • For more information, visit the product page here

    Metalized (Conductive) Fabric

    Metal Plated Flexible Fabrics and Non-Woven Textiles


    For more information, visit the product page here

    Conductive Elastomers

    Block EMI – In Any Weather, Anytime.

    Sometimes, the standard silicone gasket just won’t do. Differing weather conditions, operating temperatures, levels of chemical exposure, corrosion, and environmental fluctuations call for gaskets that are designed to shield electromagnetic interference in environmental-specific settings. Our electrically conductive elastomers provide environmental sealing, excellent mechanical functionality, and electromagnetic shielding so your enclosures receive the best protection possible with optimal electrical performance.

    Your closure problem usually starts like this: you’ve constructed an effective shielding system using a metal housing and lid. But when you combine the flat surfaces of both units, you notice a slight opening. Suddenly, gas, liquid, or high frequency electromagnetic energy have an easy-access path to your shielding system, which can worsen under high pressure and corrosion. Thankfully, our resilient, conductive elastomers can seal this opening by conforming to surface irregularities in your shield’s enclosure.

    We offer versatile forms of elastomers such as:
  • Diverse filler particles within our line of ElectroSeal gaskets
  • Wire in solid and sponge elastomers, impregnated wire mesh, and expanded metals within our line of ElectroMet gaskets

  • For more information, visit the product page here