It doesn't even have to be the fault of the receiving entity, whether
that be a new location or new owners. I worked in the semiconductor
industry for over 30 years and saw several examples of "lost recipes"
simply because the original process was never properly investigated,
characterized, and documented in the first place. Processes that had
produced excellent product for years might suddenly shift because some
influence that had never been understood at all changed.
We actually had one product that shifted dramatically for the worse
because a piece of equipment was upgraded to a cleaner version, and it
took a lot of engineering work to understand the favorable impact that
the carrier lifetime killing effect from the older, dirtier equipment
had on the product.
I think most people would be appalled to learn how poorly many
manufacturing processes are characterized in many industries, but it's
probably understandable given the extreme difficulty of defining all
possible influences in the first place, and then rigorously testing (or
even modeling) all possible interactions of them.
73,
Dave AB7E
On 7/9/2016 7:41 AM, jimlux wrote:
On 7/9/16 1:21 AM, Ian White wrote:
Several good points there, about the variability of ferrite cores.
Ferrites are, quite literally, "bakery products". Just like bread and
cakes, the properties of ferrites depend on the correct ingredients
measured out in precise quantities, on the precise manner in which those
ingredients are mixed, and also - most critically - on the
temperature/time profile of the baking and cooling.
Just like baking, the manufacture of ferrite materials is a complex
blend of science and know-how. Once a specific product has been
developed, consistency can only be achieved by repeating exactly the
same processes for every batch.
It is very easy to see how QC problems could appear from outsourcing
those critical processes to an offshore company that lacks the original
manufacturer's in-house know-how, with a language barrier that prevents
that information being accurately transferred.
It doesn't even have to be offshore. Not all ovens are the same either
in temperature profile or internal distribution, and there's a lot of
other aspects.
There's more than one instance of a company "losing the recipe" even
in the same plant, but also when moving manufacturing operations.
When Microsemi bought Symmetricom, they moved the Chip Scale Atomic
Clock (CSAC) manufacturing (entirely within US and carrying over some
of the same people), and lost the recipe somewhere, adversely
affecting the operating temperature range.
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