I wouldn't. That is the last thing I would recommend. But it depends on the use environment. QFNs already have major issues with solder joint cracking due to CTE mismatch. It is more likely you will have SJ reliability issues with ENIG than with HASL or IAg. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of James Mahoney Sent: Tuesday, August 19, 2008 12:37 PM To: [log in to unmask] Subject: Re: [TN] Maximum HASL thickness for SMT of QFN Yes but I would recommend immersion gold when possible Thank you, Jim Mahoney Quick Turn Flex Circuits, LLC Applications Project Manager P# 603-821-6571 F# 603-821-5723 M# 603-305-6250 ** This email and all attachments have been scanned prior to being sent** Confidentiality Notice: This page and any accompanying documents contain information that is confidential, privileged or exempt from disclosure and is intended for the exclusive use of the addressee. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution or use of the contents of this information in any manner is strictly prohibited. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of James Verrette Sent: Tuesday, August 19, 2008 1:22 PM To: [log in to unmask] Subject: [TN] Maximum HASL thickness for SMT of QFN What is the maximum SnPb HASL thickness/uniformity that can be tolerated in the SMT assembly of a .5mm pitch QFN package? Is there anyone else out there putting .5mm pitch parts on HASL finished boards that is willing to share their experiences? Jim Verrette Senior Electrical Engineer --------------------------------------------------- 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 -----------------------------------------------------