Ken: You might try to make the plastic housing/box itself out of a conductive composite. We have some polymer composites which can be injection molded, and which shield to high levels. This would get around having to redesign the circuit and also some of the problems you cite with coatings (peeling, etc). Any interest in this?
Vijay Wani The Dow Chemical Company Office (989) 636-0473 Fax (989)638-9289 vw...@dow.com From: Joseph Randolph [mailto:j...@randolph-telecom.com] Sent: Thursday, October 16, 2003 11:37 PM To: 'Ken Javor'; emc-p...@majordomo.ieee.org Subject: RE: metallic coatings Hi Ken: Conductive coatings are tricky, and I generally try to avoid them. It can be difficult to get good electrical connections at the separations where different parts of the box meet, unless the mating surfaces have been specifically designed for the purpose. Even so, the contact quality can deteriorate over time with some materials. Worse yet, some coatings have a tendency to peel as they age. I would think these limitations would be even more of an issue for military environmental conditions. I don't know the background of your request, but if this is being contemplated as a band-aid for an EMC problem, you may want to pursue other fixes such as circuit board revisions. If you really do need some shielding but want to avoid the coatings, you might consider a stamped steel insert made out of thin sheet metal that conforms to the inside contours of the plastic box. There are also some shielding constructions where a conductive film is bonded to a non-conductive substrate that can be die stamped and then folded to fit around the circuit board inside the plastic housing. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 (USA) j...@randolph-telecom.com http://www.randolph-telecom.com > -----Original Message----- > From: owner-emc-p...@majordomo.ieee.org > [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of Ken Javor > Sent: Thursday, October 16, 2003 10:03 PM > To: emc-p...@majordomo.ieee.org > Subject: metallic coatings > > > > Does anyone have any suggestions for a metallic coating that > can be deposited on the interior of a plastic box that would > need to meet military environmental conditions? Suggestions > for other metallization techniques are also welcome. > > Thank you. > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: emc_p...@symbol.com > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > Archive is being moved, we will announce when it is back > on-line. All emc-pstc postings are archived and searchable on > the web at: > http://www.ieeecommunities.org/emc-pstc > > This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
