Dewey, You make it sound like I died and this is my eulogy. Past my prime? You been talking to my wife? As to the rest, I think you been sniffing the cactus flowers again............. Doug Pauls "Whittaker, Dewey (AZ75)" <Dewey.Whittaker@ To HONEYWELL.COM> [log in to unmask] Sent by: TechNet cc <[log in to unmask]> Subject Re: [TN] Question about ENIG and 05/16/2006 03:05 other surface finishing PM Please respond to TechNet E-Mail Forum <[log in to unmask]> ; Please respond to "Whittaker, Dewey (AZ75)" <Dewey.Whittaker@ HONEYWELL.COM> Either tis' true that the memory is the first to go Or Doug Paul's fame has "Stoop"ed to a new low Some may think he has past his prime But we say not in our life time To defend his position he'll go toe to toe Cause his answers will always win, place or show With all his expressions he could be a good mime although what he lacks in rhythm, he makes up in rhyme In honor of Doug Pauls; Owner of the answer " It depends". Wannebe Poet-laureate of tech-net Friend And truly great supporter of our Industry Dewey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Roger Stoops Sent: Tuesday, May 16, 2006 7:34 AM To: [log in to unmask] Subject: Re: [TN] Question about ENIG and other surface finishing I just received a question from someone inside my organization asking about why not use ENIG instead of Iag because of storage issues... Doing a quick Internet search took me to a paper at http://www.mse.uiuc.edu/Faculty/Shang/Preprints/1997-2006/JMR00-pilin.pd f#search='tin%20nickel%20intermetallic%20strength' discussing "a comparative fatigue study of solder/electroless-nickel and solder/copper interfaces." It's dated from 2000 and does not include any study using Pb-free solders. Final thought is that Sn-Ni SJs do not behave well under high stress environments after aging. Found a few others, Daan's website was also very helpful, but time does not permit further discussion. We have used ENIG, Iag, HASL, Pb-free HAL, and it seems our choices (as far as I have anything to say about it) will likely be Iag and Pb-free HAL, due to our operating environment and quality requirements. So, should one use ENIG instead of other SFs? In the now immortal words of (can't remember who, sorry), "It Depends"... Roger -----Original Message----- From: Stadem, Richard D. [mailto:[log in to unmask]] Sent: Monday, May 15, 2006 4:50 PM Subject: Re: Question about ENIG and other surface finishing Good points, George. Trouble is, in order for the temperature under a large BGA to reach 220C for any duration, the rest of the component leads on the assembly will be close to what? 235C? Not a good process for some components. The problem with the logic that the ENIG will work better at higher reflow temperatures seen with Pb-free processes is this: The plating issues that cause the nickel oxide formation during the immersion gold step (related to the phosphorus content, amongst other variables) are exacerbated by subsequent temperature excursions. If the plating is properly done, then yes, perhaps the IMF formed to nickel will be more easily accomplished. However, if NOT done properly, the higher temperatures will make the Black Pad and other nickel plating process-related problems much, much worse. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of George Milad Sent: Monday, May 15, 2006 2:15 PM To: [log in to unmask] Subject: Re: [TN] Question about ENIG and other surface finishing I believe one of the key issues in assembling ENIG parts is that the inter-metallic formed is a Ni/Sn. Ni/Sn inter-metallic requires higher peak assembly temperature and a longer dwell at peak temperature. The right re-flow temperature profile is a must. The recommendation of ENIG assembly is 220 C for 20 seconds. Some of the failures with ENIG may be attributed to colder assembly temperatures. The transition to Pb-Free should favor ENIG as the assembly temperature for Pb-Free is going to be higher and the Ni/Sn inter-metallic will always be formed successfully. Best regards George Milad [log in to unmask] National Accounts Manager for Technology Uyemura International Corporation Technical Center 240 Town LIne Rd Southington CT 06489 (516) 901 3874 (mobile) (860) 793-4011 (office) (860) 793-4020 (fax) --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 1.8e 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 1.8e 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 1.8e 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 1.8e 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 -----------------------------------------------------