Feed-Through Board showing the PCB, the signal
connector and the ground spring
The Feed-Through boards provide
the electrical connection between the signal wires (anodes) inside the
gas box and the Front-End Electronics outside. On the inner side of the board,
the wires are soldered onto pads on the PCB,
while on the outer side an SMD connector
is placed to provide the interface to the Front-End Electronics.
The Feed-Through board also provides the connection to a
common ground reference
via a continuous ground layer following the path of the signal.
The cathode of the straws and the (inner) Aluminum side of the panels
are directly soldered onto the GND layer of the board.
A special contact spring provides then the ground connection to the
As integral parts of the straw-tubes modules,
the mechanical details of
the Feed-Through boards are described in the
sub-assembly drawings. From the mechanical point of view, there are
two types of Feed-Through boards, namely "U" and "L",
depending on which module end they fit into.