Bill:

Flex is a custom designed and custom produced product so it will always cost
more than a catalog item. You pay for the high engineering content which is
always needed  when something new is in the works. Compared with PCB's, flex
is far more compex because the substrate is less stable dimensionally which
means you need much more elegant tooling and tool concepts. All this hits at
the startup which means small orders can be really costly.  Ever order a
scustom automobile?  duPont charges well over $150 per pound for  typical
flex dielectric compared with maybe $15 or so for PWB materials. ----begin
to see the picture?

When you buy a piece of flex you are buying both an interconnections device
and a  piece of assembly tooling. Not at all fair to compare wire cost with
flex cost---remember that wire is cheap, but takes a great deal of ghand
labor to convert into an interconnection. Flex sharply reduces the assembly
labrto---wire sharply increases it.

Rigid flex is the most complex and difficult flex product to built. It
contains mixed dielectrics and requires a greatdeal of in-process tooling.
Compared with PCB's, rigid-flex takes at least 3X the manufacturing steps.
When you factor in ridiculous MIL spec  testing (which is primarily based on
the concept of a guaranteed loss of 20% of production)  you begin to sense
why rigid-flex is costly. But rigid-flex makes all sorts of high density,
high-rel packages possible; without rigid flex we would not have  any of our
high-tech  weapons systems, smart bombs, etc. If it's a matter of bringing
the pilot back alive after a successful mission, would you carp about a few
dollars?

Can't understand your application----I don't see how you could replace a
rigid-flex board with a piece of ribbon cable and a connector. I think you
are in need of a good applications engineer.


Tom Stearns
3 Brander Court
Nashua NH 03063
603 889 2522

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