Fully Laminated EMI Shielded Windows
Fully laminated windows in glass or plastic can be produced either as individual windows or, for smaller sizes, in sheet form and machined into segments. All fully laminated EMI shielded windows are available with or without a step and with or without a silver painted busbar. Surface treatments for scratch resistance or anti-reflectance are available and tinted inter-layers for anti-reflectance or contrast enhancement can be supplied on request.
Standard terminations for individually produced emi shielded windows are flying mesh, foil or silver painted busbar or conductive gasket. Sheet-cut windows, including stepped types, are only available with silver busbar and optional emi gaskets. Care should be taken with stepped windows, particularly glass ones, as the pressure exerted by the gasket under compression can easily overstress even a fully laminated window. We suggested that stepped windows should be plastic or a composite where the glass pane is not under pressure when mounted.
Most gaskets in our range can be used with shielded windows and the actual type selected will depend on the degree of shielding and environmental protection required. Please contact us for technical advice.
Edge Bonded EMI Shielded Windows
Edge bonded windows use the same substrates and mesh as the fully laminated versions, but are only laminated around their edges, outside the 'viewing area', and are lower cost. They are not as suitable for stepped construction but if the windows are relatively small or when the viewing area remains smaller than the smallest of the two pieces (i.e. bezel mounted where the edge remains covered albeit stepped) it is not a major problem. Edge bonded emi shielded windows can be curved by utilising 'matched pairs' of window blanks but do not feature the use of tinted inter-layers. Standard edge bonded windows are a cost-effective solution for most commercial applications.
Cast Plastic EMI Shielded Windows
Cast shielded windows are formed by encapsulating the mesh gauze within a thermosetting plastic or resin substrate. The process has advantages inherent to the manufacturing technique, such as surface finishes, tints, minimum thickness and physical strength. The process necessitates a silver busbar termination although a stepped construction is possible during the machining of the cast blank. Cast windows cost more than edge laminated ones but are more robust for specialist applications.
Glass, including clear, diffused and hardened.
Polycarbonate including clear, hard-faced, anti-reflective, tinted, polarised and filtered.
Polycarbonate can also be conductively coated with ITO (Indium Tin Oxide) but this is a restricted option as a minor scratch on ITO can dramatically reduce its shielding effectiveness.
Woven copper (which can be anti-reflective treated) or stainless steel mesh. Typically 100 OPI.
Other wire types including knitted meshes, finishes and OPI configurations are available to order - minimum order quantities apply.
Shielding effectiveness in dB, typical values tested in accordance with MIL-STD-285 with test samples of woven copper mesh 300 x 300 mm.
It is important to note that a smaller test sample would return a far higher attenuation and all manufacturers data should be compared on this basis to avoid misinterpretation.
|Frequency||Field||100 OPI||50 OPI|
|Glass thickness||± 0.5 mm|
|Overall dimensions||± 1.0 mm to 300mm,
± 1.5 mm to 600 mm
|Plastics thickness||± 0.5 mm per piece|
|Overall dimensions||± 0.5 mm to 300 mm,
± 1.0 mm to 600 mm
Generally by description and customers drawings indicating dimensions, finishes, fixings, gasket type and method.
Please contact us to discuss your individual requirements.
Please contact us to discuss your gasket or frame requirements.