1. From the ATLAS SCT endcap module production to the commisionning
D. Ferrère, University of Geneva
in behalf of the ATLAS SCT collaboration
Overview:
Introduction of SCT
The endcap modules and the specifications
The module production and logistics
Production results: yield and statistics
The endcap macro-assembly: status and results
The integration and commissioning
October 05, 2005
D. Ferrère, RD05 Florence

2. Atlas Experiment
Good tracking performances that are required for:
Secondary vertices
Impact parameters resolution
Track isolation
Measurement of high momentum particles
Barrel Toroid
Main physics motivation is the search for the Higgs boson, but not only given the large range of physics opportunities!
Barrel Electromagnetic Calorimeter
October 05, 2005
D. Ferrère, RD05 Florence

3. The SCT Semiconductor Tracker
SCT is made of 4088 modules:
~ 61 m2 of silicon
15,392 silicon wafers
~ 6.3 million of readout channels
Layout was done such that
4 space points can be reconstructed
5.6 m
1.04 m
Endacp C: 9 wheels
1.53 m
Endacp A: 9 wheels
4 barrels
October 05, 2005
D. Ferrère, RD05 Florence

4. center of the wheel. Pitch between 70 to 90 m.
Endcap module types
1976 modules mounted on the 2 endcaps:
936 Outer Forward Modules
640 Middle Forward Modules (incl. 80 Short Middle)
400 Inner Forward Modules
Middle short
A module consists of 768 readout strips on each side with a constant angular pitch pointing towards the
center of the wheel. Pitch between 70 to 90 m.
October 05, 2005
D. Ferrère, RD05 Florence

5. Expanded view of an outer module
2 detectors strip-chained and readout at one end by 6 binary chips (ABCD3T) on each side  768 readout strips per side.
Clock, control and signal are transmitted optically.
Detectors are mounted back to back with a 20 mrad stereo angle.
October 05, 2005
D. Ferrère, RD05 Florence

6. Module requirements Electrical specifications:
(Based on a full set of digital/analog chip characterization + bias tests)
Noise occupancy at 1 fC less than 5x10-4 also related to the input noise
Less than 1 % dead channels ( 15/1536 ) – From the response curve test
Detector current less than 20 mA at 350V per detector.
Long Term Test (LTT) operation for hours cold:
thermistor on hottest part of hybrid at ~10 ºC
Chip and detector biases and currents should remain stable
top side
bottom side
October 05, 2005
D. Ferrère, RD05 Florence

7. Module requirements Mechanical specifications:
XY alignment - 13 parameters defined but critical are
Front-to-back detector alignment: midYF within ± 5 m
Individual detector angles: a1 to a4 within ± 130 mrad
Mounting hole and slot alignment: mhx, mhy and msy within ± 20 m
Z detector profile – 50 points are focused on the Si-detectors and per module side. None of them should exceed ± 115 m envelope.
The alignment and the profile must survive 10 thermal cycles between +35 ºC down to –30 ºC
Chip and fanins must be assembled within a defined envelope to avoid clashes with neighbor modules
Ceramic mounting surface should be clear of cracks (very fragile part)
13 XY alignment parameters
50 Z focus points for the module profile
October 05, 2005
D. Ferrère, RD05 Florence

8. Module production and endcap flow diagram
Cracow INP
Freiburg Univ.
CLRC, RAL
Module production and endcap flow diagram
Hybrids
(Cicorel + Freiburg)
Fanin production
(CNM Barcelona)
Spine Production
(Protvino)
Spine QA & rework
(CERN)
Hybrid QA Site
Complete
Si-Detectors
(Hamamatsu & CiS)
Module Production
and QA Cluster
Others: Washers, glue
EndCap C
macro-assembly
Liverpool (UK)
EndCap A
Nikhef (NL)
In progress ...
Freiburg Univ.
Geneva Univ.  CERN
Manchester Univ.  Liverpool,
Glasgow
MPI, Munich  Prague Charles Univ, Prague Czech Tech. Univ.
Melbourne  CERN
Nikhef
Valencia
ID Integration
Tests and cosmic run
CERN SR1
January 2006
March 2006
ID Installation
CERN ATLAS pit
May/June 2006
October 05, 2005
D. Ferrère, RD05 Florence

9. Module assembly resources
- 7 assembly sites in total involving 12 institutes or Universities
Up to 6 technicians/site (~3 FTE) for the module assembly
Up to ~8 physicists and PhD per site (~2 FTE) for the module QA
Component selection and reception tests ~2h
Alignment and assembly of detectors ~2h + 24h glue curing
Detector current check and visual inspection ~40min
Assembly with hybrids and fanins ~1h h glue curing
Wire bonding ~3h
Detector current check and visual inspection ~15min
Metrology survey ~30min
Thermal cycling ~18h
Electrical characterization ~2h30
Long Term Test electrical characterization ~24h
Inspection and packing for storage ~20min
From start to the end a module fabrication takes
~9 working days/module!
In practice a module is issued after 3 to 4 weeks!
October 05, 2005
D. Ferrère, RD05 Florence

10. Module assembly procedure
Assembly with spine
Module assembly procedure
Detector alignment
Assembly with hybrid and fanins
Wire bonding
October 05, 2005
D. Ferrère, RD05 Florence

11. Production Started in June 03 and completed in May-June 05
Endcap module production
Production Started in June 03 and completed in May-June 05
Front side of an outer module
Max production rate:
~55 modules/week
Total : 2377
Outer : 1106
Middle : 775
Inner : 496
Number of modules were made with a 20% contingency to allow up to 15% lost at the production sites and 5% at the macro-assembly sites.
Outer : 94.7%
MidL : 94.4%
MidS : 88.3%
Inner : 87.4%
Average yield : 93.1%
October 05, 2005
D. Ferrère, RD05 Florence

12. Module is out of detector current specs!
Few illustrations of problems found – Part of the learning curve
Teflon surface
Detector scratches due to trapped debris into the teflon surface of the transfer plate.
Module is out of detector current specs!
Si surface
Detector broken due to debris that was sticking on the backplane. This happened when sucking down on the miniature alignment stage.
Module is broken!
The spacer mounted on the spine was glued with an angle and clash during the assembly was unavoidable but impossible to anticipate.
Module was aborted!
October 05, 2005
D. Ferrère, RD05 Florence

13. Electrical QA results Good Out of specs Good Out of specs
October 05, 2005
D. Ferrère, RD05 Florence

14. Mechanical QA results Some stats on essential XY alignment parameters
Pass
Good
Good
midyF specification inside ± 5 microns
mhy specification inside ± 20 microns
Good
Stereo angle specification 20 ± 0.13 mrad. Defined between front and back detector axis.
October 05, 2005
D. Ferrère, RD05 Florence

15. Mechanical QA results ZminF Front and rear detector profile Pass Good
October 05, 2005
D. Ferrère, RD05 Florence

16. 52 outer and 40 inner modules
Endcap macro-assembly
Liverpool: Endcap C & Nikhef: Endcap A
40 middle modules
Rear side
52 outer and 40 inner modules
Front side
Disk 5A in Module to Disk stand at NIKHEF
October 05, 2005
D. Ferrère, RD05 Florence

17. Average Input noise on the complete endcap C
Endcap C disk testing results (Liverpool)
Average Input noise on the complete endcap C
Outers : 1576e-
Middles : 1529e-
Inners : 1070e-
Short Middles : 907e-
Endcap A has similar results so far...
October 05, 2005
D. Ferrère, RD05 Florence

18. Endcap C disk Thermal study (Liverpool)
Tcoolant= -22 ºC, Tambient= -8 ºC
Average±RMS:
Hybrid main point: ± 0.8 ºC
Detector-end temp: ± 0.6 ºC
(T. Jones)
October 05, 2005
D. Ferrère, RD05 Florence

19. Delivery to CERN in January 06 Delivery to CERN in March 06
EC-C cylinder with discs 6 to 9 at Liverpool
Endcap status
Endcap C (Liverpool):
Module to disc completed and tested
Discs 9 to 5 in cylinder
FSI to mount on discs 1 to 4
Service to cylinder started: cooling, LMT, fibers, DCS
Delivery to CERN in January 06
EC-A Disk 8A inserted into cylinder at Nikhef
Endcap A (Nikhef):
Module to disc completed from 9 to 5
Disks 9 to 7 in cylinder
Disk 5 under test
Modules to be mounted on disc 4
Services to discs on disc 1 & 3 to do
Services to cylinder started: cooling, LMT, fibers, DCS
Delivery to CERN in March 06
October 05, 2005
D. Ferrère, RD05 Florence

20. Integration and commissioning at CERN SR1
The 2 ECs will arrive at CERN in January 06 and March 06
Reception tests: visual inspection, leak test and electrical tests
Final SCT assembly
Integration with TRT
Combined tests SCT/TRT - 9 SCT discs will be tested together on 1 sector
Installation into the pit foreseen in May and June 06
Cantilever stand with 1 endcap
TRT trolley in aligned position
for the integration
October 05, 2005
D. Ferrère, RD05 Florence

21. Conclusions SCT is one of the largest Si-Tracker (~61 m2).
A lot of expertise is essential from physicists, engineers and technicians in various fields such as: physics, mechanics, electronics, computing, thermodynamics,...
Even with the strict requirements, a module yield as high as 93.1% was achieved modules have been built and 1976 will be used in SCT.
The EC module production was a great success and experience in all the assembly sites: 7 sites involving 12 universities and institutes.
Modules are completely mounted on discs for EC-C and half for EC-A and module performances are as expected!
The macro-assembly, service assembly, integration and commissioning are on the way or about to start at Liverpool, Nikhef and at CERN.
The installation into the pit is close: May 06 and June06.
October 05, 2005
D. Ferrère, RD05 Florence

22. Extra slides
October 05, 2005
D. Ferrère, RD05 Florence

23. Running conditions and features
23 overlapping interactions every bunch crossing (at the full Luminosity)
A bunch-bunch crossing every 25ns (40MHz)
Maximum equivalent 1 MeV neutron fluence after 10 years is ~ n/cm2
Operating temperature on silicon detectors is -7oC to contain the reverse annealing and the leakage current
BUT the maintenance will likely require yearly warm-up of 2 days at 20oC and 2 weeks at 17oC
Operation in a 2 Tesla solenoid field
Material < 0.4 X0 at the outer SCT envelope
SCT coverage up to =2.5
More than 99% hit efficiency is required
October 05, 2005
D. Ferrère, RD05 Florence

24. Module components Hybrid:
- 6 copper-kapton layers laminated onto a carbon-carbon substrate
- Equipped with 12 ABCT3T readout chips and opto-chips for clock/control and readout
Detectors:
5 detector types made in 4 inch wafers by 2 manufacturer (Hamamatsu and CiS)
770 strips (1st and last not readout) of 20 micron width with an average pitch of ~80 mm
Fanins:
Aluminum strips on glass used for electrical connection and thermal isolation between hybrid and detectors. Different sets for the 3 module types.
4 items per module: 2 left and 2 rights
Spine:
Made of TPG (Thermal Pyrolytic Graphite) for the excellent thermal conductivity and AlN ceramic pieces for the mechanical stiffness. All in one single item during the module assembly.
Location pads:
very precise hole and slot made on an Aluminium washer and glue onto FR4 piece. The slot washer is glued on the spine and the hole is overlapping the hybrid and the spine.
October 05, 2005
D. Ferrère, RD05 Florence

25. SCT production Database
Oracle DB (kernel 9i)
SCT production Database
Why?
Traceability of the items, shipped items, assemblies and tests that had been made
Most of the relevant test data and parameters were stored in structured way otherwise stored in raw data
Useful GUI has been made either for upload or report thanks to:
Java applications for massive data upload
Web interfaces (SQL form) for individual data access or report
Java or other applications coupled with root display for statistics and reports
Encourages auto-discipline. Data transparent to all the collaboration and DB entries were one of the requirements to be qualified for the module production.
October 05, 2005
D. Ferrère, RD05 Florence

26. Electrical QA results Long Term Test (LTT)
After some stats decreased from 24h to 18h duration
Very rare problems found with the modules (0.05%)!
In principles problems are detected earlier during hybrid LTT.
October 05, 2005
D. Ferrère, RD05 Florence

27. Endcap macro-assembly
October 05, 2005
D. Ferrère, RD05 Florence