Electronics Forum | Wed Dec 13 11:11:20 EST 2000 | CAL
CONFUSED???? The the "BIG-chip-in-the-middle" on my image is IC732. IC304 is the 52pin QFP to the right of the "BIG-chip-in-the-middle".If it worked when the "Thingy" was there and does not work when the "thingy" is not there good indications are you
Electronics Forum | Wed Oct 25 12:24:02 EDT 2000 | Philip
Hi Chris! I hope this will help you! The CBGA uses an array of high melting point solder spheres(Sn10/Pb90) to connect its ceramic chip carrier to an epoxy glass (FR4) PCB using eutectic (Sn63/Pb37) solder joints at both ceramic and card inter
Electronics Forum | Fri Aug 25 05:23:46 EDT 2000 | Wolfgang Busko
Hi Murad, like with many other questions it�s hard to judge without seeing the effect. Assuming that this site you�re talking about is well equiped with knowledge and that they handle their processes normally to everybody�s satisfaction it�s obvious
Electronics Forum | Mon Aug 07 14:02:54 EDT 2000 | Brian W.
If you are satisfied with the apertures, then you need to check placement pressure, plant humidity, and the reflow profile. If the placement pressure is too great, it will separate minute portions of the solder from the pad. When the solder reflo
Electronics Forum | Thu Jul 27 21:57:16 EDT 2000 | Dave F
Hi Doug: Responding to your questions: � If gold over nickel is self limiting ... You didn�t say whether you gold plating was electroless or immersion. Electroless is not is self limiting. It can plate up to 5 thou. Expect immersion plated gold to
Electronics Forum | Wed Jul 12 21:47:41 EDT 2000 | Dave F
Celiav: Mark is probably spot-on on his comments about a board fab problem. It is weird that you have similar problems from two suppliers though. Recommendations are: � Get rid of any bird brain contractor that installs processes that affect your
Electronics Forum | Fri Jul 14 16:35:03 EDT 2000 | Dave F
Celia: Ubet. Sorry about the ranting. (It comes with the territory.) I don�t recall any peer reviewed stuff, but I seem to remember a couple of articles on white tin in "SMT" "Circuits Assembly" Magazine (er suppin� like that), but it was probabl
Electronics Forum | Thu Jul 13 04:01:02 EDT 2000 | JohnW
Dave, Firstly..how the heck are you?..been a while.... Ok so I'm running an Electrovert Electra witha hot gas knife, & I've got large server boards going over the wave. I've seen us loose chip, mainly Tants on the hot gas knife...ain't good especia
Electronics Forum | Wed Jun 14 08:08:56 EDT 2000 | Wolfgang Busko
Hi ji tae, we had a similar problem with QFPs 0,5 pitch processed by one subcontractor. The symptoms we noticed were: - the solderjointshape and wetting looked normal - the surface had a dull gray appearance - by pushing a lead sideways with a tweez
Electronics Forum | Wed Apr 12 20:41:31 EDT 2000 | Dave F
Russ: That�s a pretty stand-up postin� bud. It�s neat that you can root-out that dirt. We couldn�t dig-up that stuff, if they threatened to shoot the dog. You could be correct about using convex for waving. We don�t wave RNET as Philips suggests
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