We recently had a small lot of pwa's (qty 3),where a large quantity of the SMT chips on the backside of the boards (approximately 60 on each board) came off during the wave solder process. It appears that the glue failed during some stress, (not a poor bond line), when viewing the "failed" locations,(within the same glue dot) some of the glue stayed on the board and some came off with the part. (Also the glue dot size was adequate) The boards are mixed technology boards where all the thru-hole components are assembled to the top side of the board, then the SMT components (chip capacitors, mainly 1210's) are glued to the back side of the board using Loctite 348 and the glue is cured in an inline oven. We ran 3 other lots (similar designs) the same morning, using the same glue, and the same process, with no part loss. (also this board has been run in the past without these failures) The only visible difference between these boards and the other 3 lots is they appear more warped. I'm wondering if when loading the board onto the wave solder fingers (removing the warp that was on the board) could this have caused the glue to crack and weaken to a point where they could have fallen off in the wave. (we did see the parts in the wave after the boards were processed). Has anyone out there had a similar experience or have some theories???? Thanks....... Stan Raytheon Towson, Md ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################