| Hi Ron, | Your question really opens up a "Pandora's box", but when you say you're not able to print perfectly, what is it exactly that you mean? Is the print lacking volume? Is it mis-registered? Are you bridging? Also, what printers have you used? Do they have vision? Or is the board being located with tooling pins? Let us know some more specific details about the problems you're experiencing, and the types of printers you have used, and I think I can be more helpful with some suggestions that may point you to a fix. In my experience, it is pretty rare nowdays to have a board so out of spec from the cad data that you've been provided to generate the stencil, that you can't get a decent print...that's provided the stencil has been made correctly within certain guidelines that are necessary to get good paste release from the apertures. I'm at NEPCON now, participating in the TAC line. We're building a double-sided PCMCIA board that has a 15.7mil 256-pin TQFP, 20-mil TSOP's, 256-ball BGA, Micro BGA's, a Flip-chip, 0402's, 0603's, 0805's, SOT-23's, and some 50mil SOIC's. The board is turning out pretty good (considering we only had 3-days to set the line up and run product for the show!) This is a flip-line too, and it's been quite a challenge to get all our machines to talk to each other and "tweek" things in so we don't look like idiots....(GRIN). This board is only only .020" thick, and is pretty flexible, so that in itself can introduce some variables as far as having a nice stable surface that is repeatable to print on, but we're doing it. One of my specialties is printing, so if you can provide a few more details about your situation, I'm sure I can help you... | -Steve Gregory- Steve, How's the show? I hope to make it next year. I have tried only HTI-9,and HTI-3's. These are the only screen printers we have The HTI-9 has vision that aids in setting up but,does not read fiducial marks automatically.I have not tried any other vendors equipment. I do build other boards from a different customer that are similar in complexity and size and don't have any trouble with them. I build double sided 20mil pitch boards on a regular basis with minimal defects.Today,I built a new board with 15mil pitch.I used a laser cut stencil that worked great. The first board out of the machine was perfect not one short.I was very happy with the outcome of the stencil,for we always used chem etched and chem traps on the aps. I wipe under after every print.It's just these two particular boards. Thanks for replying and have some fun while your there! Ron
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