Sqeeeak, sqeeak, yiell, yiell, whimp, whimp, I give up, you are right, Hans. MIL people won't like acidous residues under the BGA. I have seen what can happen: the solder bump's lead be lead away as ions into the soup and then Merlin makes the soup to nice cabbage crystals, as I mentioned earlier. You know Apple's symbol, will look something like that on one side of the bumps. The only solution I will recommend hereafter is Lipton's tea with a little milk added for cleaning under BGAs. The guy with the 20 different white residues will be disappointed: we will never have the time to dig so deep into the white residues, just find fastest way to avoid them. Visited a Motorola course once, was about BGA soldering. They underlined one issue time after time: paste application (many methods) is the key to it all, if properly done, residues will be a minor problem. Queer enough the most lead-drained BGAs were from Mota, but I don't thing there is a connection, they just happened be in front of the Pb-badger. If you We will probably get further assistance from a MIL qualified lab next door. If there is a final BGA residue story to tell, we will let you readers know. -----Original Message----- From: Hans.Hinners Sent: den 25 augusti 1999 17:08 To: Ingemar.Hernefjord Cc: Hans.Hinners Subject: RE: [TN] BGA solder residues > Ingemar, > > Will the MIL people scream? > Arrrrgggggghhhhh. An unofficial scream from a MIL person. Hans ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################