Transcript AUW_2014_tsurin

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
I.Tsurin
Liverpool University
08/04/2014
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ATLAS Upgrade Week 2014, Freiburg, April 7-11
quad 3
Data
Power
quad 4
quad 2
DCS
(omitted in
1st prototype)
quad 5
quad 1
Please refer to Stephan Eisenhardt's
presentation on 07/04/2014 for global
overview of the EndCap readout
I.Tsurin
Liverpool University
08/04/2014
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ATLAS Upgrade Week 2014, Freiburg, April 7-11
Quad Module hybrid prototype
Single 1/2 oz copper clad
printed circuit board
(second PCB version has
got a double copper clad
for solid ground)
100 mm FR4 base material
Minimum track and
gap width 0.15mm
(standard and safe)
I.Tsurin
Liverpool University
08/04/2014
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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 AXT540124 connector
pin-compartible with existing hybrid designs
I.Tsurin
Liverpool University
08/04/2014
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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
08/04/2014
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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
08/04/2014
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ATLAS Upgrade Week 2014, Freiburg, April 7-11
Layout features
Edge wire bond pads for
connectorless mounting
Unrouted signals are wire
bonded on the PCB
Pads for the pick-up tools
Beefy paths for LDO bypass
capacitors
Aignment marks / bond-off
pads for assembly
I.Tsurin
Liverpool University
08/04/2014
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ATLAS Upgrade Week 2014, Freiburg, April 7-11
Quad Pixel Module assembly
"Yellow" FE-I4Bs
0.5 kg
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
Populated PCBs are
glued on top of four
ASICs with Epolite
FH 5313A adhesive
(replica of Quad Sensor)
I.Tsurin
Liverpool University
08/04/2014
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ATLAS Upgrade Week 2014, Freiburg, April 7-11
Hybrid Test Card
RJ45 connector for clock,
command and data
Jumpers to select the ROC
8-way Molex connector for
sensor bias and ASICs'
supply voltages
Quad pixel module with
AXT530224 receptacle
plugged into AXT630124
header on the test PCB
Carbon fibre plate for
Quad module mechanical
handling and cooling
I.Tsurin
Liverpool University
08/04/2014
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ATLAS Upgrade Week 2014, Freiburg, April 7-11
First test results
LDO power scheme with bandgap reference voltages
(shunt regulators disabled)
All ROCs are configured, one is being readout at a time
Tuning for 8 ToT (20 ke) and 3000e threshold using USBPix
Threshold spread
Noise distribution
Tuning results are sensitive to substrate connection
I.Tsurin
Liverpool University
08/04/2014
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ATLAS Upgrade Week 2014, Freiburg, April 7-11
Threshold and noise scans
I.Tsurin
Liverpool University
08/04/2014
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ATLAS Upgrade Week 2014, Freiburg, April 7-11
Summary
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)
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)
AXT connector needs different pinout for high voltage
application (Panasonic's absolute maximum rating is 60V)
I.Tsurin
Liverpool University
08/04/2014
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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
I.Tsurin
Liverpool University
08/04/2014
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