Medical Materials

EMC/EMI/RFI SHIELDING MATERIALS →

Electromagnetic compatibility (EMC) is a concern that engineers must design for in medical electronics since functional abnormalities may have severe consequences. EMC design of medical electronic devices, including shielding for electromagnetic interference (EMI) and radio-frequency interference (RFI), is more complex than design for nonmedical counterparts.

As with many devices, especially today's very small ones, shielding, filtering, and heat dissipation must be considered. The use of EMI / RFI control materials throughout the design minimizes the chance of any malfunction later. Such materials can include gaskets and seals made from absorbent elastomers that bridge uneven seams in electronic packaging. EMI/RFI shielding is essential in devices used in medical applications, and this shielding is provided by Faraday cages that surround components and serve as barriers. These cages are made of flexible materials supplied by many of our world-class suppliers, like 3M and others. Common EMI/RFI materials include:

• Foil tapes
• Metal-filled elastomers
• Wire mesh
• Copper foil tapes
• Conductive fabrics laminated with conductive adhesives
• Absorbing materials and pads

FILMS & PAPERS

EIS' world-renowned suppliers provide specialty films and papers used in medical devices, disposables, diagnostic equipment, transdermal delivery systems, and more. These materials can be die-cut for component use and function as insulation, shielding, gasketing, and adhesive mounts for body-worn devices. For device-assisted drug delivery applications and stick-to-skin medical applications, hydrophilic and hydrophobic films are integrated into the design to provide a seal against liquids while at the same time being capable of moisture vapor permeability.

We will assist all customers in determining the best films and papers for a specific medical application and intended use. Converted adhesive films and insulating papers, for example, are provided to your exact specifications through our engineering design expertise.

LAMINATES

Our custom, complex, multi-layer laminate composites provide solutions for a wide variety of medical applications, from wound care to medical device infrastructure. Layers of facings and substrates can be designed and engineered to meet your exact application requirements. And prototypingand in-house lab testingensure that your end product meets every requirement, from non-adherence and non-linting to needed absorbancy level, air permeability, and barrier needs.

We will recommend the optimum laminating material and lamination services, helping to improve product performance while lowering material costs. Expertise for specific medical applications enables EIS engineers to collaborate on both design and production improvements. We utilize our broad base of suppliers to source various materials, including 3M laminating sheets. Factors such as durability, temperature, and electrical properties are important considerations in determining the best laminate for a given usage.

RELEASE LINERS

Our release liners include easy- or medium-release and one- or two-side releases. They are made from films and papers of various thicknesses and degrees of rigidity. EIS Fabrication Medical uses DAHLAR® 9200 release film for rigid, rigid-flex, and flexible circuit applications.

DAHLAR is a trademark of AIRTECH International Inc., and its features include:

• Maximum temperature of 250ºC
• Thickness .001"/.025 mm 350% elongation
• Easy release from most surfaces

We offer release liners that are compatible with a variety of adhesive systems. Our design and engineering team provides liner materials for optimum release characteristics required by the adhesive backing for slit and custom die-cut medical materials. Non-adhesive parts require low-tack adhesive liners that are compatible with the intended speed and accuracy requirements of the manufacturing process.

For adhesives requiring a release liner, we offer 3M™ 4999 silicone white release liners. 3M™ 4999 is a trademark of 3M Company and is available in:

• 3.2 mil thickness
• 55 lb densified kraft paper liner
• Silicone release coating on one side
• Minimum width is 3.0 inches/maximum of 54 inches
• Standard 360 yard roll

THERMAL MANAGEMENT MATERIALS

As the medical device and equipment industry continues to design for smaller, faster, and more precise instrumentation, thermal management becomes even more critical. Our thermal management experts know how to create custom solutions for thermal management using materials and adhesives from industry-leading suppliers.

EIS converts material to dissipate and transfer heat away from sensitive components to heat sinks or the ambient environment. Preventing excess heat from causing expensive and health-hazardous repercussions is factored into the system design at the start. We often use phase-change materials that change from solids to liquids while absorbing heat and adhesives placed between a heat-generating device and a heat sink.

Additionally, EIS sources the following materials from their leading thermal management material suppliers:

• Pressure-sensitive Tapes that mount components to heat sinks
• Thermal Fabrics (fiberglass reinforced, ceramic-filled polymer) that provide thermal conductivity and electrical isolation
• Thermally Conductive Liquid Adhesives
• Elastomer pads and coated fabrics that provide thermal impedance or thermal conductivity
• Silicone Sponge materials for heat absorption or heat transmission

Our in-house test laboratory allows testing of different materials, with other thermal characteristics, early in the design stage to avoid unnecessary problems, delays, and expenses.