In a message dated 2/3/99 11:11:35 AM Pacific Standard Time, [log in to unmask] writes: <> Hello Brian! I guess I'd give a shot at your questions seeing how there's no math involved (BOY! Am I ever embarrassed!) But the first thing I'd ask is if their solderpaste deposition is what it needs to be based on the pad sizes that are used for the devices. If I may ask, how fine is this pitch? Is there soldermask dams between the pads? As far as the parts shifting from "power loading", I've not been so lucky to experience that, except for a time or two when I've had to hand load some fairly populated proto's and the paste has dried quite a bit...you can deal with the touch-up on just a few boards when that happens. It would seem to me that as long as the paste isn't dry, and the part is placed accurately, and deep enough into the paste (not just set on top of it) it really shouldn't move even if there's a slight jolt here and there going down the conveyers...I might hedge a little in my answer if the part is ceramic, or if it's a PLCC, but QFP's usually stay where they're put... Going from I/R to convection really should make things easier. It should be the other way around, that is; he was experiencing bridges before with I/R, but go away with convection...at least that's what I remember when we switched ovens at one company I worked at. I've only had a chance to go through that once, every place else I've worked used convection ovens exclusively. I'd almost bet that it has something to do with the solderpaste deposition and/or footprint of the part.. -Steve "I'm no math whiz" Gregory- ################################################################ 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 ################################################################