EMI Shielding & Thermal Interface Materials

CHOMERICS is a global supplier of EMI shielding, thermal interface materials, plastics and optical products. As a distribution partner of Chomerics we have access to a worldwide network of applications engineering support & manufacturing facilities.


EMI Shielding

Parker Chomerics EMI shielding products family includes an extensive selection of EMI gaskets; shielded windows; shielded air ventilation panels; cable shielding products; grounding solutions; shielding laminates; tapes; conductive coatings, adhesives, sealants, grease and inks; conductive, injection molded plastics material; board level shielding coatings; and microwave absorber products

The EMI gasket offerings includes: conductive elastomers, wire mesh, oriented wires in elastomer, woven wire mesh, expanded metal foil, compressed mesh, fingerstock, conductive fabric over foam, and combination EMI/environmental gaskets.

Conductive elastomer EMI gaskets include molded, extruded, co-molded or co-extruded with nonconductive elastomer, form-in-place, overmolded, reinforced, connector gaskets, or waveguide gaskets.

Shielded windows can be either glass or plastic, with wire mesh or ITO coatings, and can have anti-glare, anti-reflection, hardness, and other design features.

Cable shielding products include: conductive heat shrinkable tubing and connector boots; wire mesh; connector gaskets; I/O panel gaskets; ferrites; cable grommets; and foil and conductive fabric tapes

Thermal Interface Materials

Heat generated by a semiconductor must be removed to the ambient environment to maintain the junction temperature of the component within safe operating limits. Often this heat removal process involves conduction from a package surface to a heat spreader that can more efficiently transfer the heat to the ambient environment. The spreader has to be carefully joined to the package to minimize the thermal resistance of this newly formed thermal joint.

Attaching a heat spreader to a semiconductor package surface requires that two commercial grade surfaces be brought into intimate contact. These surfaces are usually characterized by a microscopic surface roughness superimposed on a macroscopic non-planarity that can give the surfaces a concave, convex or twisted shape. When two such surfaces are joined, contact occurs only at the high points. The low points form air-filled voids. Typical contact area can consist of more than 90 percent air voids, which represents a significant resistance to heat flow.

Thermally conductive materials are used to eliminate these interstitial air gaps from the interface by conforming to the rough and uneven mating surfaces. Because the TIM has a greater thermal conductivity than the air it replaces, the resistance across the joint decreases, and the component junction temperature will be reduced. A variety of material types have been developed in response to the changing needs of the electronic packaging market.