The size of the PASA should not exceed 2 mm by 3.5 mm.
The PASA should not be packaged, rather the bare die should be mounted
on a Hybrid substrate. Each die should carry 16 channels with a pitch
corresponding to the detector anode pitch (250 
m).
The size of the PASA is one of the components that
determine the superlayer overlap area. This overlap has to be optimized to
the smallest possible area. PASA and SCA will be mounted on Hybrid, so both
dies do not have to be packaged. The size of the Hybrid is adjusted to the
size of the detector. The size of the die has to allow bond pads between
adjacent PASA.