An article short on substantiation and long on speculation, I fear.
Notwithstanding, I believe - and I've proposed this idea before - that
there is a too slavish adherence to standards rather than to common
sense. This is because the standards exist and are used but are not
applicable to many applications which do not require top quality
reliability. Just the unnecessary inspection is costly, let alone the
afterwork. It reminds me of one of my ex-customers making a lab
instrument that is used only in comfortable room conditions. He was
getting a lot of cratering on his wired through-hole SJs after wave
soldering, and he had personnel reworking these joints (which
plop-plopped for several seconds of applying the soldering iron). I
asked why and he told me that the joints were faulty. I rejoined with
something like BS. He gave me a board full of craters but which was
otherwise faulty and I did microsections of half-a dozen "faulty" SJs,
all of which showed perfect intermetallic formation along both wire and
through-hole plating, with the craters and blowholes outside the
intermetallics. This persuaded my client that the "fault" was cosmetic
and he stopped the retouching except on grossly obvious faults. From
that moment, the number of returns was reduced. For pointing out to him
that he was wasting money by a too-solicitous inspection and retouching,
he presented me with a bottle of Neuchâtel Oeil de Perdrix, which was
delicious.
Incidentally, it was this case that inspired me to develop what became
known as the "Plop-plop Meter" to measure the outgassing of PTHs. This
never got beyond prototype stage, but it worked admirably and was able
to distinguish between different causes of outgassing. However, I wasn't
convinced that the market justified putting it into production; it
remained a curiosity.
In short, Standards, used appropriately, can help, as far as possible,
to perfect reliability for a given application. Used inappropriately,
they can drive up costs dramatically and with no justification; this
could drive the manufacture to E. Asia, at the cost of jobs. Maybe the
author was expressing this sentiment, albeit unscientifically and too
clumsily.
Let common sense prevail!
Brian
On 29/04/2011 19:15, Graham Collins wrote:
> Anyone else read this?
> http://www.assemblymag.com/Articles/Blog/BNP_GUID_9-5-2006_A_10000000000
> 001038283
>
> All I can say is "wow". Well, I could go on for hours, but... wow.
> Not quite how I see these specs! Working on military stuff I can attest
> that changing from MIL-STD-2000 to the IPC specs was a significant
> improvement in reality, reliability, and productivity, but that's not
> how he sees it.
>
> regards,
>
> Graham Collins
> Halifax Production Engineering
> L-3 communications Electronic Systems
> (902) 873-2000 ext. 6215
>
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