Hi Inge, Are you sure it is not smearing? Based on the picture, the polishing was done kind of directionally (all scratches are normal to the interface). I saw a similar effect of smearing a few times (the last one I remember was a layer of Cu-Sn intermetallics something like 10 -15 micron thick in a normal joint:-)) and etching the sample didn't help. Just an idea :-) Vladimir -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Wednesday, August 20, 2008 8:00 AM To: [log in to unmask] Subject: Re: [TN] Diffuse topic Mornin' Inge! Got your picture up! Go to: http://stevezeva.homestead.com/files/Nickel_Diffusion.jpg Steve -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Hernefjord Ingemar Sent: Wednesday, August 20, 2008 5:08 AM To: [log in to unmask] Subject: [TN] Diffuse topic Investigation of coax Kovar/glass feed thrues soldered to nickel plated metal bodies gave, that nickel from the feed thrue's barrel nickel plating diffused as much as 38 micrometers (!)into the tin from the tin/lead solder during the vapour phase soldering. Nickel had diffused from both the feedthrue and the package. How is that possible? Thought polish smear gave false picture, but the analyst claims that what you see is true nickel diffusion and nickel/tin IMCs. I'll ask dr Gregory for help with a photo for you all. The sample you will see is exposed more than normal to an etchant to prove that smear is not the case..start from the bottom shows nickel (black), nickel IMCs (greyish) and topmost tin (bright). There is nearly no lead present. Inge --------------------------------------------------- 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.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- 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.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- 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.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------