Thank you. Steve -----Original Message----- From: Stadem, Richard D. [mailto:[log in to unmask]] Sent: March-17-11 11:04 AM To: Steven Kelly; TechNet E-Mail Forum Subject: RE: Signal loss Here you go, sir. http://www.taconic-add.com/pdf/technicalarticles--effectsofsurfacefinish.pdf -----Original Message----- From: Steven Kelly [mailto:[log in to unmask]] Sent: Thursday, March 17, 2011 8:46 AM To: Stadem, Richard D.; TechNet E-Mail Forum Subject: RE: Signal loss Thanks Richard, Is there a number or % I can hang my hat on? Regards Steve -----Original Message----- From: Stadem, Richard D. [mailto:[log in to unmask]] Sent: March-17-11 9:44 AM To: TechNet E-Mail Forum; Steven Kelly Subject: RE: Signal loss Yes. Absolutely. At that frequency the signal skin effect is very pronounced, and having a nickel finish can prove to be very lossy. You may wish to investigate immersion silver finish instead. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steven Kelly Sent: Thursday, March 17, 2011 8:30 AM To: [log in to unmask] Subject: [TN] Signal loss Good Day To All, We recently fabricated a surface microstrip flex circuit with 50 ohm +/- 2.5 ohms (results were good). The impedance traces were not covered with solder mask or coverlay but were plated with ENIG. The next part is where I need the help. The circuit runs at 20-26 Ghz. Customer says the return losses from the S-parameters measurements are good but the insertion losses are not (quite frankly I have no idea what this means) . Could the nickel plating be causing this issue? Thanks. Steve Kelly --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/ContentPage.aspx?Pageid=E-mail-Forums for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/ContentPage.aspx?Pageid=E-mail-Forums for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------