Stave 4004(Genova) z-problem

1
Stave4004(Genova) Z-shift problem
Initial Z tuning was not symmetrical
POS_1(m6c)?400?m POS_13(m6a)?500?m for
module-step distance (however within tolerance
280-500?m for this distance) Mean positions
should be shifted by 50?m
The remaining Z shift can be explain by
temperature effect and impossibility to control Z
position of module on deposition table.
2
Temperature dependence
Mauros results(before Pixel week)
Dummy module was glued on stave at 270C and then
another dummy module was deposited by robot at
the same place at other temperatures.
This shift had an opposite direction!
After Pixel week Experiments with screws it
was possible to obtain the shift from 0 to 70 ?m
per 30C by tightening/relaxing different screws
(unfortunately not in the right direction)
Shift of module on stave position due to change
of temperature is big and cant be
controlled/predicted. The only way is a
temperature stabilization.
3
Deposition table
Flex covers a module-pin contact place
FE was glued on table so now its possible to
control a module position on the table.
4
Actions

1. Temperature of the setup will be controlled and
   monitored with digital thermometer (2 sensors in
   different places). No way for robust temperature
   stabilization (too big room) so deposition moment
   will be changed if needed.
2. Z position of module on deposition table will be
   controlled with microscope (glued FE marks).
3. Initial Z tuning on stave will be done by
   symmetrization of 4 step-module distances
   (m6a,m6c,m1a,m1c positions)