Hi Lee! The primary issue are need to address is "how much wetting is required". As other TechNetees have described, you are not melting the solder ball so you will end up with various levels of wetting. Your BGA left solderball is acceptable and the BGA right solderball may also be just fine despite its visual appearance. IMHO the BGA left solderball is acceptable as it has good wetting for a non melting solder alloy situation (it just doesn't have the anticipated wetting height). My recommendation is to sacrifice a couple of BGAs, do some cross sectioning and setup a go/no go wetting scale for inspection use. You could also play with your stencil apertures to potentially increase wetting characteristics. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] Lee Whiteman <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 05/17/2010 08:52 AM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to [log in to unmask] To [log in to unmask] cc Subject [TN] MORE 90 / 10 SOLDER BALL QUESTIONS I just posted a photograph of a 90 Pb / 10 Sn BGA solder joint on the IPC Photo Gallery, that was soldered with eutectic SnPb solder and an eutectic SnPb solder thermal profile. The BGA on the left hand side is "acceptable", but the BGA on the right hand side shows a clear line of demarcation. My initial thoughts was to check the thermal profile, to see if it got to a high enough temperature. Any thoughts and comments? Thanks. Lee Whiteman, PMP Senior Member Engineering Staff L-3 Communications East Telephone: (856) 338-3508 FAX: (856) 338-2906 E-Mail: [log in to unmask] ______________________________________________________________________ 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.asp?Pageid=4.3.16 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.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------