Bill,
I can't answer your questions 1 & 2 as well as others on Technet can, but I
did want to offer my view on your customer.
Having been on both sides of that fence (PCB assembly @ in-house OEM,
Contract Assembler, and OEM Assembly Customer), I can appreciate your
problem, but your customer obviously has very little industry experience,
and cannot possibly have data to support his claim that .020" lead
protrusion yields any more strength at all over minimum discernable
protrusion (ie. he is totally in the dark, because he has his head...).
I think that most/all on Technet with pertinent experience will agree that
there will be no strength difference between the prtotrusions allowed in
J-STD-001B and your customers tighter spec.
In answer to 3) The customer will need to be encouraged to show data to
support his claim, and then shown industry data (available from several of
the seminars given on joint reliability, and pertinent articles) which
refutes his now unsupported claim. Then he will need to be given the delta
in cost to perform to his now discredited requirement. All this must be, of
course, done politely!
4) For almost all uses, when interpreted/applied correctly, J-STD-001B is
on the money. For very high reliability users/uses, it can be, at times,
not quite as tough as some people would like. However, in this case, I
feel your customer is dead wrong.
Bill Spalton
Sr. Supplier Engineer
EMC Corporation
Hopkinton, MA 01748
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Original Text
From "Kasprzak, Bill (esd) US" <[log in to unmask]>, on 8/7/97 9:04 AM:
To: <[log in to unmask]>
Technetters:
We have a customer that we are working with concerning J-Std-001. The
customer wants to take exception to many portions of the standard as
written
and instead impose different criteria. For example, Lead protrusion for
leaded components should range from discernible to 1.5mm (.060 ). This is
according to paragraph 6.5.3 of J-Std-001B. Our customer wants to impose a
.020 to .060 range for lead protrusion. The feeling being that the
discernible lead protrusion results in a solder joint with less strength
than one with more lead protrusion.
My questions are:
1) The criteria agreed upon in the J-Std-001, was it decided, discussed and
voted by committee ? Were there any items that passed by a 51-49 vote ?
2) What happened to dissenting views ? What issues were debated ?
3) Anyone out there with experience with a customer who wants to take
exception to certain portions of J-Std-001 ? How was the situation handled
?
4) Anyone have any comments, good or bad, about J-std-001 ?
Thanks to all who can respond.
Bill Kasprzak
Moog Inc.
716-652-2000 ext. 2507
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