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Date: | 22 Mar 1996 10:34:10 EST |
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Our company is looking at the use of plastic components on
a variety of hardware, primarily military and commercial
avionics types of products. We have setup a special project
team that has studied the moisture
sensitivity/baking/handling issues that arise when the use
of PEM devices are incorporated on a design. The team has
written in detail, all the steps associated with the
implementation of an "ideal/should be" ( zero percent risk)
process. This process addresses the identification of the
moisture sensitivity level of the parts during the hardware
design phase; identification/tracking labels and special
pacakging notes on purchase orders during procurement;
handling and re-packaging instructions for the Receiving
Inspection and Stockrooms personnel; baking, usage, storage,
tracking and equipment procedures for the Manufacturing
Floor. In short, the "ideal no risk approach".
The implementation of a process with this type of
complexity, dependent upon many inputs from various
functional groups and component suppliers seems very
difficult, if not impossible to control. Additionally, the
cost of implementatiion seems to out weigh the benifits
associated with using cheaper parts in the first place.
Also my limited contacts in the industry indicate that
baking and controlling to this degree is not necessarily
an accepted practice. Some manufactures bake all parts
(PEM's), some bake selectively and some (seems like a
majority) do not bake at all. The only common thread, is
that no one has experienced (or is willing to admit) the
hardware failures associated with entrapped moisture.
So my question is: Are the manufactures who bake, incurring
unnecessary costs and are being overly conservative in their
manufacturing process controls and addressing a non-problem?
Or are those who don't bake, ignoring a real problem that
will eventually catch up with them?
Any opinions, statements of facts or fleeting thoughts on
this topic would be greatly appreciated.
Jim Weiss
Harris Corp.
407-727-6872
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