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EMC
– The
HF Shielding of Enclosures
Electromagnetic
compatibility (EMC) is the ability of an electronic device
to work properly in an electronic environment without
causing inadmissible interference. ( DIN VDE 0870 )
RTP offers plastic enclosures with inner shielding. Thus,
the customer is able to construct and build HF (high frequency)
shielded enclosures conforming to european EMC standards.
The flat plastic is coated with Isolex R-65, a conducting
paint, which is UL listed. The use of these types of surface
coatings is well known because of their high damping coefficient
and their high electromagnetic absorption over a wide
frequency range. Discontinuities of the enclosure (bending
points etc) may be touched up by hand if required. Every
cut-out for switches, cables or air slots influences the
shielding characteristics of the final product. The HF
shield factor is dependent on the emissive power and the
frequency range of the built in electronics. In addition,
the effect of all perforations on the overall HF shielding
cannot always be determined. This is also true for the
influence of built in electronics and for the final working
environment of the enclosure. Therefore no guarantee can
be given by RTP for the shielding quality of the end product.
Optimum HF shielding of an enclosure can only be achieved
by close cooperation between the electronic engineer and
the enclosure manufacturer during the construction phase.
RTP gladly supports its customers with its technical experience
in producing HF shielded enclosures. The final testing
procedure and the EMC approval, however, remain strictly
the responsibility of each customer.
ISOLEX R-65 RFI/EMI SHIELDING COATING
R-65 is used as an RFI/EMI shielding and antistatic coating
for plastic substrates. It will yield a surface resistance
of 0.5 ohms/square or less, at dry film builds of 38-50
microns, as tested according to ASTM D257. R-65 is a mar
and burnish resistant finish that possesses high electromagnetic
absorptive properties over a broad frequency range. |
