Hi Kathy, I can give you the spec's on the stencil and solderpaste that we use to build a little "Keychain" board when we're exhibiting at trade shows. The keychain board is panelized 5-up and contains; a Tessera TV46 Micro BGA, a 128-pin 15.7-mil pitch TQFP, a pair of mini-melf's, a pair of SOT23's, a pair of 1206's, a half-dozen 0603's, and thirty-six 0402's. We print using a MPM Ultraprint 2000 decked out with metal blades, and Alpha's LR735 at 400 mesh. The stencil we use is 4-mils thick and the apertures for the Micro BGA are 1 to 1 with the pads. The stencil we use is from BeamOn Technology, and something I think is worth mentioning, chemically etched. It's not been trapezoidally etched, laser cut, or electropolished either. What they do is something called "Band-width etching", or "Band-Etch". What this is basically, is the way that they generate the artwork or phototool used to etch the stencil. The way that it works is instead of etching the whole aperture completely from the foil, they just etch a very thin line around the perimeter of each aperture, it's much easier to control that way. You don't get the kind of "hour-glass" cross section that you get with standard chemical etching that requires electropolishing to remove. There was a study done at the University of Mass. in 1996 by a class of engineering students to objectively evaluate the effects that different stencil technologies had on printing solderpaste. One of the conclusions that I found very interesting was that Band-Etched stencils performed just about as good a laser cut stencil at a fraction of the cost...not everybody can afford the $800-1200 price of laser cut stencils... -Steve Gregory- P.S. Just another note, what a lot of people did with the "keychains" that we passed out at Surface Mount International is to walk over to the Nicholet Booth and ask them to x-ray the solder joints...the guys at Nicholet were sick of seeing our keychains (GRIN). We didn't hear anything negative from anybody during the entire show....('course I did the same thing with a few of the first panels after we had set up the line and before we started passing them out...I'm no fool! hehehe) ################################################################ 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 web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################