The M.E.s at my company are struggling with replacing a defective plastic BGA. We have an Air Vac BGA machine. The lead M.E. feels that he needs a solder pad deposit in place before putting the replacement BGA on the board for reflow. He feels that he will compensate for irregular solder balls on the part and also possible surface differences on the existing pads which have been wicked clean of solder. The problem is in putting down the paste. He is teaching a technician to use a small medium stiff plastic stencil. The paste is applied with a wide chisel blade x-acto knife looking tool. They are getting uneven solder cakes and icicles between the solder deposits. I ask, is that the best way to put down paste? Is it necessary on a plastic BGA to put down a paste deposit? Will the stringers pull in when heated or will they results in shorts after reflow? Any info appreciated. Thanks, Stu Korringa Quality Engineer Smiths Industries Electronic Systems Grand Rapids, Mi. ********************************************************************** This e-mail and any files transmitted with it are confidential and may be legally privileged or otherwise exempt from disclosure under applicable law. This e-mail and its files are intended solely for the individual or entity to whom they are addressed and their content is the property of Smiths Aerospace. If you are not the intended recipient, please do not read, copy, use or disclose this communication. If you have received this e-mail in error please notify the e-mail administrator at [log in to unmask] and then delete this e-mail, its files and any copies. This footnote also confirms that this e-mail message has been scanned for the presence of known computer viruses. *********************************************************************** --------------------------------------------------------------------------------- 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 e-mail to [log in to unmask]: SET Technet NOMAIL 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------