dewar wiring

[Tony Abbey]

Posted to CCD-world:
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> Posted to CCD-world:
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> Andre, & CCD-world,
> 
> > We are replacing the constantan wiring in a dewar by the copper 
> > wiring. Wondering whether there is any reason to use something else 
> > than ordinary insulated multi-strand wire ? 
> > 

The CCD packages we have designed in partnership with EEV for use on the
European Photon Imaging Camera on ESA's Xray Multi Mirror satellite use an
aluminium block with an invar plate topped with an insulating aluminised
silicon wafer on which EEV bond the real CCD.
A flexi ribbon is glued directly on the aluminium block, and direct wire
bonds made to the CCD and the underlying aluminium layer (for the back
contact). The flexi consists of 50 microns of Kapton with 4 micron
adhesiveless copper tracks 7 thou wide (except Vss - approx 25 thou), plated
with 1 micron of nickel and 1/2 micron gold. The flexi is terminated with a
31 way miniature Cannon MDM connector soldered with indium solder. The MDM
connector is normally at approx room temperature and the CCD package has been
qualified between -150C and +150C.
We also designed carriers boards for testing of the devices up until
installation in the flight cameras - these include an anti-static captive
clamp which is used to short out all the tracks to ground when not in use.

regards

Tony Abbey                                  E-mail: afa at star.le.ac.uk
CCD Group, Dept. of Physics and Astronomy   Phone: +44 116 252 3490
University of Leicester,  University Road   Fax:   +44 116 252 3311
LEICESTER LE1 7RH,  United Kingdom

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