Hello,
I support Steve's theory, too. It is just like a volcano erruption -
throwing lava all over the place. Hand soldering did not have such issue
other than some blow holes.
Regards,
Wee Mei.
Crepeau, Phil wrote:
>another factor might be the difference in the aries adapter lead cross section area compared with the 'former' dip lead cross section area. a 'significant' difference here would be worth looking into.
>
>having said all this, though, i suspect your idea is closer to the root cause. i just love to brain storm.
>
>phil
>
>-----Original Message-----
>From: Steve Gregory [mailto:[log in to unmask]]
>Sent: Tuesday, June 22, 2004 1:37 PM
>To: [log in to unmask]
>Subject: [TN] Very Strange Solderballs...
>
>
>Hi All!
>
>Well, I'm just about at my wits end after fighting with something for the
>past two days that for the life of me, I can't figure out.
>
>Starting at the beginning, we've been building a mixed technology assembly
>for well over two years now, that practically builds itself...it's that easy.
>Has been running smoothly, and the boards don't have so much as a pimple on them
>when we're done.
>
>Recently, a 16-pin DIP IC has been very hard to get, so there was a change
>made to use a 16-pin SOIC on an Aries SMT-to-PTH adapter...you can get the SMT
>version of this part all over the place, and it's cheaper than the PTH version
>even when buying the adapter along with the IC!
>
>Didn't think there was going to be a shred of trouble with that change, but
>boy was I wrong! And this problem has me completely baffled...
>
>If you go and look at:
>
>http://www.stevezeva.homestead.com/files/AdapterSolderballs.jpg
>
>as well as:
>
>http://www.stevezeva.homestead.com/files/AdapterSolderballs2.jpg
>
>You'll see the solderballs that this whole story is about. They ONLY occur at
>the locations where the Aries adapters are being used. Another weird thing is
>that these solderballs won't wash away...even after multiple cleanings in
>either an Electrovert H-500 inline cleaner, or a Aqueous Technologies SMT800
>batch cleaner that uses Kyzen Aquanox 4512P chemistry...the only way to remove
>these little buggers is mechanically by brushing them away. By the way, I'm using
>Kesters 2331 water soluble flux in my Electrovert Electra, so it's even more
>puzzling why the solderballs won't wash away. The flux is applied with an
>OPTIFLUX-1 ultrasonic spray fluxer.
>
>I want to try and figure out why I'm getting them in the first place. I've
>been dinking with the wave profile for the last two days, changing everything
>from one extreme to another. The solderballs either get worse, or stay the same.
>I thought that maybe I wasn't drying out the flux well enough, but when I
>either increased pre-heat, or slowed down my belt speed in an effort to do that,
>the solderballs got worse.
>
>Has ANYBODY ever experienced something like this before? I'm about to pull my
>hair out!!
>
>I have a theory about this that I think I'm going try an experiment to see if
>I can prove how these solderballs may be occuring. If you look at this
>picture:
>
>http://www.stevezeva.homestead.com/files/Adapter.jpg
>
>You can see that the leads on this adapter are machined pins. My theory is
>that at the top of the pins, you see a sholder that might be effectively
>"sealing" off the barrels slightly. That shoulder sits flush on the anullar ring. So
>when the board passes across the wave, the barrel fills from the bottom up,
>which is compressing the trapped air inside the barrel to a point at which the
>barrel "burps" or "spits-up" (the Dads out there, all know about spitting up)
>the solderballs.
>
>I'm going to test my theory by putting some dissolvable spacers beneath the
>adapter so that the shoulder won't be sitting flush on the pad, and see if I
>still get the solderballs.
>
>I sure would like to hear that somebody has seen this before, and found a way
>to deal with it...
>
>Thanks everyone!
>
>-Steve Gregory-
>
>
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