Re: BeCu problem
I read in !emc-pstc that Fred Townsend f...@poasana.com wrote (in 3e3af280.5e519...@poasana.com) about 'BeCu problem' on Fri, 31 Jan 2003: John, tubes are like vacuum deposition chambers. I have difficulty believing that a fancy form of carbon would be of any use in molded structures, HV, or HVAC. These conditions are all found in radar tubes. Well, AIUI, it's actually made under high vacuum conditions, and diamond is very stable, of course. But I wasn't thinking of the applications of BeO in high-power tubes, about which I know very little, but in semiconductor packages and heat-transferring insulators. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! 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: davehe...@attbi.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
RE: BeCu problem
On that topic I remember the UK Comedian and retired explosive expert saying - of making hole in dynamite, before fitting the detonators. You're supported to use and expensive copper Prodder. I use a bit of bent fence wire If it goes bang I'll never know. From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of drcuthbert Sent: Friday, January 31, 2003 7:43 PM To: 'Fred Townsend'; John Woodgate Cc: emc-p...@majordomo.ieee.org Subject: RE: BeCu problem I worked on a 1 MW, 160 GHz Gyrotron in 1982 that used a diamond waveguide window. Yes diamond is the up-and-coming power electronics material with 50X the thermal conductivity of copper. It is also starting to be used as a protective thinfilm material. Dave Cuthbert From: Fred Townsend [mailto:f...@poasana.com] Sent: Friday, January 31, 2003 3:03 PM To: John Woodgate Cc: emc-p...@majordomo.ieee.org Subject: Re: BeCu problem John, tubes are like vacuum deposition chambers. I have difficulty believing that a fancy form of carbon would be of any use in molded structures, HV, or HVAC. These conditions are all found in radar tubes. Also, thanks to Greggs comment about fancy screw drivers, I remembered that BeCu screw drivers, wrenches, etc. are used by the military in explosive environments because of their no sparking characteristics. Fred Townsend John Woodgate wrote: I read in !emc-pstc that Fred Townsend f...@poasana.com wrote (in 3e3a35fb.6ecc...@poasana.com) about 'BeCu problem' on Fri, 31 Jan 2003: BeO has seven times better thermal conductivity than AlO (alumina). There is no real substitute for BeO at high power levels. It is still used by the Military in high power radar applications such as tubes. Vapour Phase Deposition of diamond may replace BeO, with improved thermal properties, AIUI, and no toxicity problem. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: davehe...@attbi.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: davehe...@attbi.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: davehe...@attbi.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: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we
RE: BeCu problem
I worked on a 1 MW, 160 GHz Gyrotron in 1982 that used a diamond waveguide window. Yes diamond is the up-and-coming power electronics material with 50X the thermal conductivity of copper. It is also starting to be used as a protective thinfilm material. Dave Cuthbert From: Fred Townsend [mailto:f...@poasana.com] Sent: Friday, January 31, 2003 3:03 PM To: John Woodgate Cc: emc-p...@majordomo.ieee.org Subject: Re: BeCu problem John, tubes are like vacuum deposition chambers. I have difficulty believing that a fancy form of carbon would be of any use in molded structures, HV, or HVAC. These conditions are all found in radar tubes. Also, thanks to Greggs comment about fancy screw drivers, I remembered that BeCu screw drivers, wrenches, etc. are used by the military in explosive environments because of their no sparking characteristics. Fred Townsend John Woodgate wrote: I read in !emc-pstc that Fred Townsend f...@poasana.com wrote (in 3e3a35fb.6ecc...@poasana.com) about 'BeCu problem' on Fri, 31 Jan 2003: BeO has seven times better thermal conductivity than AlO (alumina). There is no real substitute for BeO at high power levels. It is still used by the Military in high power radar applications such as tubes. Vapour Phase Deposition of diamond may replace BeO, with improved thermal properties, AIUI, and no toxicity problem. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: davehe...@attbi.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: davehe...@attbi.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: davehe...@attbi.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
Re: BeCu problem
John, tubes are like vacuum deposition chambers. I have difficulty believing that a fancy form of carbon would be of any use in molded structures, HV, or HVAC. These conditions are all found in radar tubes. Also, thanks to Greggs comment about fancy screw drivers, I remembered that BeCu screw drivers, wrenches, etc. are used by the military in explosive environments because of their no sparking characteristics. Fred Townsend John Woodgate wrote: I read in !emc-pstc that Fred Townsend f...@poasana.com wrote (in 3e3a35fb.6ecc...@poasana.com) about 'BeCu problem' on Fri, 31 Jan 2003: BeO has seven times better thermal conductivity than AlO (alumina). There is no real substitute for BeO at high power levels. It is still used by the Military in high power radar applications such as tubes. Vapour Phase Deposition of diamond may replace BeO, with improved thermal properties, AIUI, and no toxicity problem. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: davehe...@attbi.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: davehe...@attbi.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
Re: BeCu problem
I read in !emc-pstc that don_borow...@selinc.com wrote (in ofc54f7ba7.cab7254d-on88256cbf.0051d...@selinc.com) about 'BeCu problem' on Fri, 31 Jan 2003: I have seen stainless steel used as battery contacts. The contacts developed an oxide on them that made it difficult to get power from the battery. Seems to me that some plating could solve that problem however. OTOH, I have never found any problem with *magnetic* stainless steel. But nickel plate does cause film interface problems, particularly for 1.5 V or 3 V supplies. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! 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: davehe...@attbi.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
RE: BeCu problem
Good point John - then we can justify the $5,000 screwdriver. Gregg From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Woodgate Sent: Friday, January 31, 2003 10:35 AM To: emc-p...@majordomo.ieee.org Subject: Re: BeCu problem I read in !emc-pstc that Fred Townsend f...@poasana.com wrote (in 3e3a35fb.6ecc...@poasana.com) about 'BeCu problem' on Fri, 31 Jan 2003: BeO has seven times better thermal conductivity than AlO (alumina). There is no real substitute for BeO at high power levels. It is still used by the Military in high power radar applications such as tubes. Vapour Phase Deposition of diamond may replace BeO, with improved thermal properties, AIUI, and no toxicity problem. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! 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: davehe...@attbi.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: davehe...@attbi.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
Re: BeCu problem
Hi Jan, In addition to health aspects, BeCu is incompatible with most enclosure materials and coatings (to prevent rust and corrosion) used in equipment. After a couple of weeks a BeCu finger in contact with a chassis will leave a black smudge, the corrosion byproducts resulting from the battery that is formed. BeCu gaskets must be coated with an appropriate plating and not used bare. That little chart of available platinge on the back page of the gasket catalog is the most important part of the document! Doug Jan Vercammen wrote: Hello EMC/PSTC-list, I have a question concerning Berylium Copper (BeCu). Even though this is not a direct EMC oriented question, it is or could be, indirectly, a serious problem in the EMC shielding of our products. I have been asked if BeCu can still be used in Europe and the USA (and the rest-of-the world) as the material for shielding gaskets and fingers. ...deleted for brevity -- ___ _ Doug Smith \ / ) P.O. Box 1457 = Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o |Email: d...@dsmith.org \ _ /]\ _ / Website: http://www.dsmith.org 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: davehe...@attbi.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
Re: BeCu problem
I read in !emc-pstc that Fred Townsend f...@poasana.com wrote (in 3e3a35fb.6ecc...@poasana.com) about 'BeCu problem' on Fri, 31 Jan 2003: BeO has seven times better thermal conductivity than AlO (alumina). There is no real substitute for BeO at high power levels. It is still used by the Military in high power radar applications such as tubes. Vapour Phase Deposition of diamond may replace BeO, with improved thermal properties, AIUI, and no toxicity problem. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! 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: davehe...@attbi.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
RE: BeCu problem
Jan - Both Be and BeO pose health risks. While I can't point to anything to support the claim, BeCu will probably become a part of the product take back/recycling. I did text searches of the WEEE and the RoHS Directives and found no mention of Be in any form. Be and its compounds are looked at under the various voluntary ecological programs. Many of my eco links are dead, but you can refer to http://www.osha.gov/SLTC/beryllium/ for the US position. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com From: Jan Vercammen Sent: Thursday, January 30, 2003 11:04 PM Hello EMC/PSTC-list, I have a question concerning Berylium Copper (BeCu). Even though this is not a direct EMC oriented question, it is or could be, indirectly, a serious problem in the EMC shielding of our products. I have been asked if BeCu can still be used in Europe and the USA (and the rest-of-the world) as the material for shielding gaskets and fingers. The main issue here is that Berylium (probably in combination) is classified as an carcinogen and it is also know to cause lung diseases (e.g. CDB or chronic Berylium disease). Note that this is only the case if small particles are inhaled into the lungs. However, I have also received conflicting information that it is BeO (Berylium Oxide) which is or could be the cultprit. BeO is used as an electronic packaging material. Therefore I assume that the BeCu gaskets and fingers are not an health hazard when used as a shielding part in our products, but are (or could be) hazardeous during manufacturing and recycling. I have been told on several occasions that BeCu is not allowed any more, but one can not provide me with standards or legal texts to substantiate the above statements. I have also been told that we need to change the BeCu shielding parts asap to stainless steel parts. However, personally I do not feel convinced and was hoping that EMC experts on the EMC/PSTC-list could help me out with the following questions: -1- is it correct that BeCu fingers/gaskets are considered a hazardeous substance and that they will be abolished from electronic equipment? -2- if question 1 is correct, what is then the exact argument for not using BeCu?? -3- are there (world wide) legal standards/regulations published that state that BeCu (as a finished product) cannot be used anymore and by which date??? -4- what is your experience with the conversion of BeCu to stailess steel gaskets/fingers for non-dynamical shielding applications (cost, problems, ...)??? Kind regards, Jan Vercammen Agfa-Gevaert NV Mortsel, Belgium 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: davehe...@attbi.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
Re: BeCu problem
I have seen stainless steel used as battery contacts. The contacts developed an oxide on them that made it difficult to get power from the battery. Seems to me that some plating could solve that problem however. There are no good substitues for BeO in all applications. AlN is better than alumina, but not as good as BeO. If the application needs a simple flat insulator to conduct heat, and is small, diamond is a wonderful material - better heat conductivity than copper! Don Borowski Schweitzer Engineering Labs Pullman, WA Fred Townsend f...@poasana.com@majordomo.ieee.org on 01/31/2003 12:38:19 AM Please respond to Fred Townsend f...@poasana.com Sent by:owner-emc-p...@majordomo.ieee.org To:Jan Vercammen jan.vercamm...@agfa.com cc:emc-p...@majordomo.ieee.org Subject:Re: BeCu problem I can't help you with the regulations but I can clarify the usage of Beryllium a bit. When Beryllium is added to copper it makes it very hard. It is used in gaskets to make them springy. Stainless steel is a poor substitute because it lacks both the electrical and thermal conductivity. So far as I know there is no handling hazard unless you saw or grind it. Beryllium oxide BeO has similar restrictions on grinding. I don't know if it can be sawed. It would probably take a diamond blade in a liquid bath to have a chance at sawing. BeO has seven times better thermal conductivity than AlO (alumina). There is no real substitute for BeO at high power levels. It is still used by the Military in high power radar applications such as tubes. Fred Townsend Jan Vercammen wrote: Hello EMC/PSTC-list, I have a question concerning Berylium Copper (BeCu). Even though this is not a direct EMC oriented question, it is or could be, indirectly, a serious problem in the EMC shielding of our products. I have been asked if BeCu can still be used in Europe and the USA (and the rest-of-the world) as the material for shielding gaskets and fingers. The main issue here is that Berylium (probably in combination) is classified as an carcinogen and it is also know to cause lung diseases (e.g. CDB or chronic Berylium disease). Note that this is only the case if small particles are inhaled into the lungs. However, I have also received conflicting information that it is BeO (Berylium Oxide) which is or could be the cultprit. BeO is used as an electronic packaging material. Therefore I assume that the BeCu gaskets and fingers are not an health hazard when used as a shielding part in our products, but are (or could be) hazardeous during manufacturing and recycling. I have been told on several occasions that BeCu is not allowed any more, but one can not provide me with standards or legal texts to substantiate the above statements. I have also been told that we need to change the BeCu shielding parts asap to stainless steel parts. However, personally I do not feel convinced and was hoping that EMC experts on the EMC/PSTC-list could help me out with the following questions: -1- is it correct that BeCu fingers/gaskets are considered a hazardeous substance and that they will be abolished from electronic equipment? -2- if question 1 is correct, what is then the exact argument for not using BeCu?? -3- are there (world wide) legal standards/regulations published that state that BeCu (as a finished product) cannot be used anymore and by which date??? -4- what is your experience with the conversion of BeCu to stailess steel gaskets/fingers for non-dynamical shielding applications (cost, problems, ...)??? Kind regards, Jan Vercammen Agfa-Gevaert NV Mortsel, Belgium 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: davehe...@attbi.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
Re: BeCu problem
I can't help you with the regulations but I can clarify the usage of Beryllium a bit. When Beryllium is added to copper it makes it very hard. It is used in gaskets to make them springy. Stainless steel is a poor substitute because it lacks both the electrical and thermal conductivity. So far as I know there is no handling hazard unless you saw or grind it. Beryllium oxide BeO has similar restrictions on grinding. I don't know if it can be sawed. It would probably take a diamond blade in a liquid bath to have a chance at sawing. BeO has seven times better thermal conductivity than AlO (alumina). There is no real substitute for BeO at high power levels. It is still used by the Military in high power radar applications such as tubes. Fred Townsend Jan Vercammen wrote: Hello EMC/PSTC-list, I have a question concerning Berylium Copper (BeCu). Even though this is not a direct EMC oriented question, it is or could be, indirectly, a serious problem in the EMC shielding of our products. I have been asked if BeCu can still be used in Europe and the USA (and the rest-of-the world) as the material for shielding gaskets and fingers. The main issue here is that Berylium (probably in combination) is classified as an carcinogen and it is also know to cause lung diseases (e.g. CDB or chronic Berylium disease). Note that this is only the case if small particles are inhaled into the lungs. However, I have also received conflicting information that it is BeO (Berylium Oxide) which is or could be the cultprit. BeO is used as an electronic packaging material. Therefore I assume that the BeCu gaskets and fingers are not an health hazard when used as a shielding part in our products, but are (or could be) hazardeous during manufacturing and recycling. I have been told on several occasions that BeCu is not allowed any more, but one can not provide me with standards or legal texts to substantiate the above statements. I have also been told that we need to change the BeCu shielding parts asap to stainless steel parts. However, personally I do not feel convinced and was hoping that EMC experts on the EMC/PSTC-list could help me out with the following questions: -1- is it correct that BeCu fingers/gaskets are considered a hazardeous substance and that they will be abolished from electronic equipment? -2- if question 1 is correct, what is then the exact argument for not using BeCu?? -3- are there (world wide) legal standards/regulations published that state that BeCu (as a finished product) cannot be used anymore and by which date??? -4- what is your experience with the conversion of BeCu to stailess steel gaskets/fingers for non-dynamical shielding applications (cost, problems, ...)??? Kind regards, Jan Vercammen Agfa-Gevaert NV Mortsel, Belgium --- 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: davehe...@attbi.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: davehe...@attbi.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
