Low-mass tapes for the ATLAS upgrade

Tape design

The copper/polyimide low-mass bus tapes distribute all signals (data and Timing, Trigger and Control) and the electrical power to the 14 Silicon detector modules on each side of a 1.4m long barrel strip stave. We have been designing a whole series of such tapes for the international strip upgrade collaboration, to allow the comparison of different powering and readout options.
The data transmission from the silicon modules to the End of Stave is at 640 Mbps. The Timing, Trigger and Control (TTC) data is distributed to groups of up to 10 hybrids in a multi-drop configuration. Both of these are non-trivial because of the space and material constraints. We have performed Finite Element Analysis (FEA) calculations to optimize the design and the results were validated by direct measurements by our collaborators.

Tape production

With the support of the Oxford Physics Photo-Fabrication Unit we have manufactured a large number of tapes used for prototyping by the international strip upgrade collaboration.

Tape testing

The large number of traces on a low-mass tape requires an automated tape test process. We have built a two-head robot, which measures conductivity of connected pads, isolation of adjacent traces and High Voltage (HV) isolation from the HV traces. We will help our collaborators in Slovenia and USA construct copies of our tape- testing robot.

Tape testing robot


Tony Weidberg