Jorge, The first thing I would do is take problem devices and turn them upside down (i.e., "dead-bug" position) and measure the plating thickness and composition using XRF (i.e., X-Ray Fluorescence. QFP soldering problems with high tin content plating usually is an indication that the leads weren't plated correctly. If the plating on the leads isn't above 200 microinches you'll probably have soldering problems. Regards, George George M. Wenger (908)-546-4531 [log in to unmask] Celiant Corporation 40 Technology Drive Warren, New Jersey 07059 -----Original Message----- From: Jorge Rodriguez [mailto:[log in to unmask]] Sent: Wednesday, December 05, 2001 12:14 PM To: [log in to unmask] Subject: [TN] QFP Leads with 85 Tin 15 Lead finish I already sent this e-mail on the past, got one answer, I hope there is somebody out there having the same issue. Fellow Technetters: I am sending this looking for any help, I guess I've done everything as far as the process and I haven't been able to resolve the issue. We've been having soldering problems for a while with QFPs with 85 Sn/15 Pb finish on the leads. The solder doesn't flow properly and an acceptable solder joint is not formed, the leads can be sometimes lifted with no effort. The solder paste was checked after the screen printer operation and it looked alright, the oven profile was also verified and it's always within the solder paste manufacturer's recommendations. This problem seems to be affecting all the different products with this type of component. These part numbers are manufactured by Altera. Has anybody experienced similar problems with QFPs from this manufacturer?, Does anybody have recommendations as far as the reflow oven profile?. I read somewhere that this particular alloy has the liquidus temperature at 205 degrees, is this accurate? Any help would be really appreciated Jorge Rodriguez Sr Process Engineer Varian Electronics Manufacturing 615 South River Drive E-mail: [log in to unmask] ------------------------------------------------------------------------ --------- 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 To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL 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 ------------------------------------------------------------------------ --------- --------------------------------------------------------------------------------- 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 To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL 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 ---------------------------------------------------------------------------------