It is clear you've considerable experience soldering, in general, and BGA's. Someone knows why the balls don't wet to the paste "mound" though they collapse as typical. My question remains considering whether this "mound" wets, or not, to the solder termination pads. If it does not wet their either (in addition to the balls), what is of primary concern - provided your profile is as you say (looks ok for some pastes considering the 185 [56 seconds may be low] window and liquidous [how much time here?]? You know the heat is concentrated at the BGA corners. If the profile is low, your corners may wet while edge balls do not - or may be wetting marginally. Still feel uncomfortable with ball collapse but not wetting to the "mounds." Earl Moon --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------