Hi All!! First, I wanted to thank everyone who responded to my post last week about suggestions for an experiment to conduct to show the importance of cleaning, I owe a few of you some beers! Thanks again! Now I gotta' nuther one...it's to do with µBGA layout. We just got a prototype kit in here that has a 144-pin µBGA with a cavity. I recieved the stencil gerber and looked at the size of the apertures in order to know what I should specify for my stencil. The apertures in the gerber were 15-mils in diameter, which is not out of the ordinary. The µBGA shares the board with a bunch of 50-mil stuff, so I ordered a 6-mil thick stencil and had my stencil vendor do a rounded square for all the µBGA apertures (per a suggestion by Vern Solberg on Tessera's WEB page AND it works!). But when we got the fabs and I got a chance to see them, there's something I noticed that concerns me...only because I've never seen it before on a µBGA footprint. What the designer did, was on pins that share a common signal, instead of laying out a 15-mil diameter circle for one pad and running a 5-mil wide trace to the next 15-mil circle, he laid out a big fat 15-mil wide trace between the two points and defined each pad point with a circular opening in the solder mask...does that sound okie-dokie to ya'll? To me, it seems like shades of building RF boards where parts share the same pads and stuff...and what a pain in the butt that is! There's about half a dozen places like that in the footprint...one or two of those fat trace points have 3 or more pads for the device that will solder to them. I have never seen this used before and I don't know if it's gonna cause me problems assembling it...have any of you ever seen this done before? Does it cause problems? Thanks in Advance! -Steve 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 ################################################################