| am working on the design of a showboard to demonstrate our | assembly capabilities. we are working with double sided assemblies involving BGAs and CSPs. could someone suggest | types of BGAs/ CSPs (type, name, I/O, etc)that would be a challenge to work on, are representative of the latest in the research community (and yet are gettable) | Ash Hi Ash! Just a question and a some suggestions. Are these boards something you want to use to demonstrate to potential customers coming to your facility, or are they something that you want to build at a trade show and then hand out to visitors? If they're to be hand out boards at a show, you don't want to get too crazy pushing the technology limits. What may be certainly doable in a stable environment like a normal production floor, can turn out to backfire on you at a show. You've only got 4 - 5 days to get the line set-up and running good before the exhibitions, and that's not a whole hell of a lot of time, especially when almost all of your machine set-up (spotting the machines, getting power and air, etc.) has to go thru the union guys. My point is, you don't get much time to work and tweek the process after the machines are ready to blaze. Like I said earlier, you don't want to push things too much, but be bold enough so that you'll catch peoples eyes. When I was doing the shows, the last board we built was a little "Keychain Fob"...you've seen em' everywhere. But people liked the looks of the ones we built, it had a Tessera TV46 micro BGA, a 15.7-mil pitch 128-pin TQFP, couple of SOT23's, couple of MELF's, some 1206's, 0805's, 0603's, and a ring of 0402's around the Tessera chip. We did them in panels of 5-up and had them routed, tab'ed, and scored so it would be easy to depanelize while we stood around in our suits (Geeze I hated that! I can't stand wearing a friggen' noose!) People are going to check up on you at the shows. If you build something and hand them out, they're going to take whatever it is that you're building and give it a inspection like it's going into a nuclear missile warhead or something, so you want to be sure that you can do this well. There's nothing worse than setting something like this up and wind-up building crappy stuff, even if it is non functional...you'll have a very hard time living it down. People were taking the keychain fobs that we were passing out over to Nicholets booth and getting them x-rayed until Nicholet got tired of x-raying Zevatech keychain fobs from everybody. As far as where to get the parts, that's all gonna depend on what it is you want to build. Dummy components can be had from different companies that make their living selling them (Topline, Practical Components, Soldering Technology, to name a few...), so you'll pay quite a bit for them. If you can establish some contacts with somebody at any of the manufacturers of the devices, you sometimes can get their process fallouts (mechanically good, just electrically no good) at material cost, or sometimes for nothing, you just got to call around. As far as passive components go, I'd just buy some real zero ohm packages instead of getting them from the dummy component vendors. They charge just as much as real components but you can't count on the solderability being good all the time, I know...from experience. Topline charges $100 a reel for 0402's...(check what real zero ohm resistors cost). You don't even want to know what they charge for Tessera chips, or the 15.7-mil TQFP's... If there's any other suggestions you'd like, or anything you'd like me to expand upon, jes' give a shout!
-Steve Gregory-
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am working on the design of a showboard to demonstrate our...
- Sep 18, 1998
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