Hello to everyone, IPC 7711, #5.7.1 and #5.7.2 is about using wire solder, or solder paste to prefill lands for BGA/CSP Installation. I was just wondering if its standard practice to use a soldering iron/solder wire to melt little blobs of solder onto the PCB before placing a BGA for rework...maybe I'm not understanding the concept of pre-fillnig lands. And I was also wondering if this "prefill" procedure is used only when placing NEW BGA chips, or if it would apply if you take a chip off, and try and place that same one back one without fully reballing it. And I was also wondering if there are any comments about installing BGA chips during rework, whether its better to use stencils of some sort to put paste between the chip and the board, or if just flux will do. And if stencils are the way to go, if you would recommend a stencil that puts paste onto the chip, or if the paste goes on the board. Personally from what I understand, replacing a BGA works just fine if you use tacky flux and then put the BGA in the rework station. Not sure why there is even a market for BGA rework stencils. Thanks to all those that reply... =) Toby --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------