Howie Thanks. Yuriy and i have been discussing this. Issue came up in a correlation study. Results are striking in some applications. Everything i've read discusses loss only, but group delay distortion in the transition regions is quite stunning. Sent via DROID on Verizon Wireless -----Original message----- From: Howard Johnson <howie03@xxxxxxxxxx> To: si-list@xxxxxxxxxxxxx Sent: Fri, Aug 27, 2010 17:14:30 GMT+00:00 Subject: [SI-LIST] Electroless Ni-Au Plating impact on microstrip losses Dear Scott, Clyde Coombs' "Printed Circuit Handbook", 5th ed., section 32.4 incorporates a good summary of the "Electroless Nickel / Immersion Gold" (ENIG) process, plus several other related processes. He quotes the typical layer thicknesses, but does not mention high-frequency losses. His book, regarding ordinary pure Nickel plating, was the source of data I used in the following overview article. The article is not a technical study, but does describe the nature of the lossy effect: "Nickel-Plated Traces", (2002) http://www.sigcon.com/Pubs/news/5_6.htm The immersion Gold platings added on top of Nickel are (according to Clyde) so thin (much less than a skin depth at multi-gHz) than they have no bearing on the losses -- it's as if you had an ordinary Nickel-plated trace as in my 2002 article. Yuri Shlepnev has done a lot of work with boundary-layer field simulations and may have more information on this topic. Best regards, Dr. Howard Johnson, Signal Consulting Inc., tel +1 509-997-0505, howie03@xxxxxxxxxx www.sigcon.com -- High-Speed Digital Design seminars, publications and films -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Scott McMorrow Sent: Thursday, August 26, 2010 3:40 PM To: silist Subject: [SI-LIST] Electroless Ni-Au Plating impact on microstrip losses Sorry about that. This is the question I sent out. Is anyone aware of any published research on Ni-Au plating over Microstrip and the impact on losses other than: "Ni-Au Surface Finish Effects on RF Performance", D. Staiculescu, J. Laskar, J. Mendelsohn, E. Sweetman, D. Rudy and I. Artaki , IEEE MTT-S Digest, 1999, pp 1909-1912. -- Scott McMorrow Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 (401) 284-1827 Business (401) 284-1840 Fax http://www.teraspeed.com TeraspeedR is the registered service mark of Teraspeed Consulting Group LLC ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu