I.Tsurin Liverpool University 08/04/2014Page 1 ATLAS Upgrade Week 2014, Freiburg, April 7-11 I.Tsurin, P.Allport, G.Casse, R.Bates, C. Buttar, Val O'Shea, S.Burdin, D.Forshaw, M.Milovanovic Development of hybrid for EndCap Quad Pixel Module Contents: Hybrid design features First test results Summary and open questions Acknowledgment: Tony Affolder, Ashley Greenall, M.Wormald, Bonn University colleagues

quad 1 quad 2 quad 3 quad 4 quad 5 Power Data DCS (omitted in 1 st prototype) I.Tsurin Liverpool University 08/04/2014Page 2 ATLAS Upgrade Week 2014, Freiburg, April 7-11 Please refer to Stephan Eisenhardt's presentation on 07/04/2014 for global overview of the EndCap readout

I.Tsurin Liverpool University 08/04/2014Page 3 ATLAS Upgrade Week 2014, Freiburg, April 7-11 Single 1/2 oz copper clad printed circuit board (second PCB version has got a double copper clad for solid ground) 100  m FR4 base material Minimum track and gap width 0.15mm (standard and safe) Quad Module hybrid prototype

I.Tsurin Liverpool University 08/04/2014Page 4 ATLAS Upgrade Week 2014, Freiburg, April 7-11 Key Design Features Single sided PCB: twice less copper, hybrid glued directly on sensor's backplane (under HV) saving material further. Fail-safe circuit for AC coupled clock and command signals Bypass capacitors at both ends of supply rails for Low DropOut voltage regulators External shunt current setting resistors Extension tab with 40 way AXT connector pin-compartible with existing hybrid designs

I.Tsurin Liverpool University 08/04/2014Page 5 ATLAS Upgrade Week 2014, Freiburg, April 7-11 Fail-safe circuit for AC coupled input signals 0V measures between '+' and '-' LVDS inputs of the ROC, thus external fail-safe circuit is necessary for them. Implemented scheme provides 25 mV differential voltage with 600 mV common mode voltage for 1.8V unregulated supply common to all four ROCs.

I.Tsurin Liverpool University 08/04/2014Page 6 ATLAS Upgrade Week 2014, Freiburg, April 7-11 Shielding scheme Bus tape may have a shield to protect ROCs' supply and sensor's bias voltages from high frequency signals. This shield is tied to ground on a hybrid through a capacitor or zero Ohm jumper. If unused, the shield track could beef the ground connection. Aluminised backplane (under HV) of the quad sensor is AC coupled to ground on a hybrid to shield ROCs from high frequency signals

I.Tsurin Liverpool University 08/04/2014Page 7 ATLAS Upgrade Week 2014, Freiburg, April 7-11 Aignment marks / bond-off pads for assembly Layout features Pads for the pick-up tools Edge wire bond pads for connectorless mounting Unrouted signals are wire bonded on the PCB Beefy paths for LDO bypass capacitors

I.Tsurin Liverpool University 08/04/2014Page 8 ATLAS Upgrade Week 2014, Freiburg, April 7-11 Quad Pixel Module assembly PCBs are glued onto 0.3 mm thin carbon fibre plate with non-conductive bottom surface - to rigidise PCBs - to shield ROCs from high frequency signals (replica of Quad Sensor) Populated PCBs are glued on top of four ASICs with Epolite FH 5313A adhesive 0.5 kg "Yellow" FE-I4Bs

I.Tsurin Liverpool University 08/04/2014Page 9 ATLAS Upgrade Week 2014, Freiburg, April 7-11 RJ45 connector for clock, command and data 8-way Molex connector for sensor bias and ASICs' supply voltages Carbon fibre plate for Quad module mechanical handling and cooling Quad pixel module with AXT receptacle plugged into AXT header on the test PCB Hybrid Test Card Jumpers to select the ROC

I.Tsurin Liverpool University 08/04/2014Page 10 ATLAS Upgrade Week 2014, Freiburg, April 7-11 First test results LDO power scheme with bandgap reference voltages (shunt regulators disabled) Tuning results are sensitive to substrate connection Threshold spread Noise distribution Tuning for 8 ToT (20 ke) and 3000e threshold using USBPix All ROCs are configured, one is being readout at a time

I.Tsurin Liverpool University 08/04/2014Page 11 ATLAS Upgrade Week 2014, Freiburg, April 7-11 Threshold and noise scans

I.Tsurin Liverpool University 08/04/2014Page 12 ATLAS Upgrade Week 2014, Freiburg, April 7-11 Summary Promptly avalaible 30-way AXT connectors were assembled providing 5 pins for power supply. The quad module draws 1.7A current, thus 40-way AXT connectors have to be used to beef the number of pins for input power and ground. (Panasonic's absolute maximum rating 300mA / pin) Real estate of the PCB with major components groupped in two columns and free central area simplifies design of handling tools for the quad hybrid (vacuums pickup and press molds for glueing) AXT connector needs different pinout for high voltage application (Panasonic's absolute maximum rating is 60V)

I.Tsurin Liverpool University 08/04/2014Page 13 ATLAS Upgrade Week 2014, Freiburg, April 7-11 Open questions 1. Integration of hybrid into readout system: through a connector or wire bonding 2. Further development: Accommodating Module Protection Chip and Data Multiplexer Chip Data Multiplexer Chip could be placed as a mezzanine board in the central area where all signals meet together Placing Module Protection Chip on the hybrid requires discussion