Hi All! Got a situation here that I think is secondary reflow... Have a board here that has some J-leaded DRAM that in functional test, they can get the board to pass test by putting some pressure on top of some of the 40-pin J-leaded DRAM's that are causing them to fail... Out of SMT things look fine, but I have observed some boards that have failed, show an unusual solder joint appearance after wave. The board is "swiss-cheesed" with vias, and none of them are tented. Every pad has a via, they alternate, some have .050" traces to the pad, some have .020" traces to the pad. Where we're seeing problems is where there is a bank of them (like a grid of 2 by 8 of them layed-out side by side). I'm thinking secondary reflow because of the open vias...or could be CTE mis-match between the part and the board. It's a .062" FR4 board, with fairly large 40-pin SOJ's, could be experiencing some hellacious mismatch, no? The gull-wing parts we don't see the problem, even though the via placement is the same standard as with the J-leaded parts...J-leads aren't as compliant? Gonna hook-up the mole tomorrow, attaching it to one of the J-leaded parts to learn what it is seeing...will tell me a lot... Just wondering if anybody else has run into this before... -Steve Gregory- --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------