| | | Hi Guys, | | | | | | I am going to be graced with the good luck of processing microBGA's in the near future. A bit of a step forward from printing 20-mil pitch and wave soldering 0805's, wouldn't you say? | | | | | | So, any of you folks who have already experienced this pleasure, could you please be so kind as to fill me in on the tips, tricks, pitfalls, etc, before I embark on my new adventure? | | | | | | Thanks a bunch, | | | | | | Chrys | | | | | Chrys, | | | | We ran our first 1mm uBGA's about 6 months ago. The operators didn't even notice them. We run 1:1 apertures on DEK 265's with FPA and high resolution cameras. Our Fuji's have "lizzard tongues" for full arrays. | | | | In rework, we run micro-stencils with the same apertures. The only trouble is we've seen no rework. There are other factors involved as our BTU profiles and solder paste selection - going to no-clean next month. | | | | There's more as .8 mm stuff but little change expected but higher resolution cameras on our PNP. | | | | Best wishes, | | | | Earl | | | Earl, | | I will also startup the production implementation of BGA's and uBGA's by the end of this year. | I am a bit concerned about the cleaning issue with BGA's. For the moment we are still using RMA paste and we need to clean our boards (military specs). I have noticed that you will go to no-clean next month. Has this anything to do with problems of cleaning boards populated with BGA's and uBGA's? | | PhilB | PhilB,
Yes and no. I mean it first is a function of economics. Then, it is a function of having to clean under the little critters (couldn't use my normal term here but it would rhyme with truckers).
I realize your concern and I wonder how you will be impacted going to no-clean. Can you really do that and meet MIL-SPEC requirements. I just can't remember all I forgot about this stuff.
Also, we're having interesting times gluing 0603's. Our latest X-Sections reveal some interesting stuff. With an acceptable toe fillet, we're OK. However, we see glue clearly under the heel fillet and sharing space with entrapped flux. When it's no-clean, no problems?, but the glue combined with the acceptable toe fillet makes for a very strong attachment. We're studying the conductivity issues more than those concerning attachment reliability over time.
I'll keep you all posted.
Earl
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