Stephen,
You didn't mention if the boards were more than 2 layers or if you
already have all the boards made. Yes, we've had similar problems. If
you haven't built all the boards yet, by all means call the vendor and fix
the hole. If they are 1-2 layer boards you'll probably get out the drill. If
they're multilayer and all built, you're sorta screwed. (Liquid Nitrogen
should shrink the lead even more, so I'd keep the mittens) If multilayer,
you may still have the possibility that those 2 particular hole have nothing
but non-functional internal pads, so you could still redrill. Otherwise, I
know of nothing better than biting the bullet and scrapping the boards.
Hopefully, somebody will come up with a better idea that I haven't heard
of in 20 years. I suppose, since they're just prototypes, you could just
bend the lead and tack it down like a SM component, depending on
vibration. Otherwise, get your knife out and shave the lead like
sharpining a pencil. (That's an old utinsil we used to use to draw on
velum with. Do you know how to spell hand drawn?)
Good luck,
Larry Campbell
>>> "Stephen R. Gregory" <[log in to unmask]> 08/24/98 09:57pm
>>>
Hi ya'll!
I'm pretty sure that one or two of you "ol' crusty" types (I mean that in a
GOOD way), have run across this problem I have a time or two. I have
this
board I'm building in a quasi "prototype/pre-production" run that has a
PTH
rectifier diode installed vertically...some of you have may have guessed
what
my problem is already from my subject, the hole's too small.
Lead diameter is right around .050" +/- a mil or two, guess what the hole
size
is? .050", +/- a mil or two...that's just peachy ain't it? It goes two times
per board, and we gotta' build a hundred of these, maybe two hundred.
So tell me, what have all you "old salts" done to make a square peg to fit
in
a round hole? I've had some REALLY GOOD suggestions from some
"experts" here,
one was to get a dremel and drill the hole out (sounds good to
me!...snicker),
another was to get a can of "Freeze-it" and spray the diode leads with it,
then hurry up and stuff it in the hole before it warms up and
expands...that
sounded pretty keen too, except it's hard to hold the diodes when you're
wearing mittens to keep from getting your digits frostbitten.
So I told my "helpers" that I really appreciated their suggestions, but that I
would like to give the technet a chance to offer some guidance to me,
and that
no-way were the suggestions from the TechNet going to be as good as
theirs,
but I wanted to see what popped up...and I would come to them if I
needed
anymore "help"...in other words, don't call me, I'll call you.
I'm sure glad this is email, it would be kinda' hard to carry on this
conversation with my tongue in my cheek like this...
So, what's the verdict? Am I hosed? I looked around on the NET trying to
find
the same spec'd diode with smaller lead diameters, but no joy. The only
two
companies I found were Motorola and General Instruments, and they
both listed
the same thing that I have now.
Is there any trick that any of you have done to make something like this
work?
I'm afraid if I don't figure something out, I'll be in mittens spraying diodes
with freeze-it on the production floor...ya' gotta save me!
-Steve "soon to be numb-fingers" Gregory-
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