Dave, the following was my best reply. I have seen SS metal
cruciform support structures and I suppose that would be difficult but
the right way to go.

 Others suggested Cu-Invar-Cu foils and/or double the layer stack.

Mike
At 04:14 PM 5/19/99 -0400, KELLY M  SCHRIVER wrote:
**** Start of Attached Message(s) ****
Mike -

Is your design such that it might permit use of an aluminum support ring,
possibly with a cruciform structure to absorb the center loads?  A bonded on
fiberglass structure might also work.

I've not had a lot of success getting laminate and foil to absorb loads of
this nature over the long haul.  Too often, we've ended up with either an
overly complicated or overly expensive board as a result.

Good luck - Kelly




At 12:41 PM 5/20/99 -0700, Dave Hoover wrote:
**** Start of Attached Message(s) ****
Did you get an answer to this?

Dave Hoover

==================================================================

  I currently fab 6" round probe cards using 12 ly cynate ester
and 1 oz copper. I need to minimize my deflection to withstand 25 lb
force exerted from 800+ pins.
  What laminate material and copper wt would be recommended to reinforce
my .125" thick PC cards?  Must be mid-range cost.



,

Mike Guenther    [log in to unmask]
Stafford, Texas

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Mike Guenther    [log in to unmask]
Stafford, Texas

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