October 05, 2005 D. Ferrère, RD05 Florence 1
From the ATLAS SCT endcap module production to the
commisionningD. Ferrère, University of Geneva
in behalf of the ATLAS SCT collaboration
Overview:Overview: Introduction of SCT Introduction of SCT The endcap modules and the specificationsThe endcap modules and the specifications The module production and logisticsThe module production and logistics Production results: yield and statisticsProduction results: yield and statistics The endcap macro-assembly: status and resultsThe endcap macro-assembly: status and results The integration and commissioning The integration and commissioning
October 05, 2005 D. Ferrère, RD05 Florence 2
Atlas ExperimentAtlas Experiment
Barrel Electromagnetic CalorimeterBarrel Electromagnetic Calorimeter
Barrel ToroidBarrel Toroid
Good tracking performances that are required for:
Secondary vertices
Impact parameters resolution
Track isolation
Measurement of high momentum particles
Main physics motivation is the search for the Higgs boson, but not only given the large range of
physics opportunities!
October 05, 2005 D. Ferrère, RD05 Florence 3
The SCT Semiconductor TrackerThe SCT Semiconductor Tracker
4 barrels
5.6 m
1.04 m
1.53 m
SCT is made of 4088 modules:
• ~ 61 m2 of silicon
• 15,392 silicon wafers
• ~ 6.3 million of readout channels
Endacp A: 9 wheels
Endacp C: 9 wheels
Layout was done such that 4 space points can be reconstructed
October 05, 2005 D. Ferrère, RD05 Florence 4
Endcap module typesEndcap module types
1976 modules mounted on the 2 endcaps:1976 modules mounted on the 2 endcaps:
936 Outer Forward Modules936 Outer Forward Modules
640 Middle Forward Modules (incl. 80 Short Middle)640 Middle Forward Modules (incl. 80 Short Middle)
400 Inner Forward Modules400 Inner Forward Modules
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.
Middle short Middle short
October 05, 2005 D. Ferrère, RD05 Florence 5
Expanded view of an outer moduleExpanded 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 requirementsModule requirementsElectrical 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 A at 350V per detector.• Long Term Test (LTT) operation for 18-24 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 requirementsModule requirementsMechanical 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.
• Chip and fanins must be assembled within a defined envelope to avoid clashes with neighbor modules
• The alignment and the profile must survive 10 thermal cycles between +35 ºC down to –30 ºC
• 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 Module production and endcap flow diagram
Module Productionand QA Cluster
Com
plete
Fanin production(CNM Barcelona)
Spine Production(Protvino)
Hybrids(Cicorel + Freiburg)
Others: Washers, glue
EndCap C macro-assembly Liverpool (UK)
EndCap A macro-assembly
Nikhef (NL)
In progress ...
Hybrid QA Site
Spine QA & rework(CERN)
ID InstallationCERN ATLAS pit
May/June 2006
ID IntegrationTests and cosmic run
CERN SR1
January 2006 March 2006
Si-Detectors(Hamamatsu & CiS)
• Cracow INP• Freiburg Univ.• CLRC, RAL
• Freiburg Univ.• Geneva Univ. CERN• Manchester Univ. Liverpool,
Glasgow• MPI, Munich Prague Charles Univ, Prague Czech Tech. Univ.• Melbourne CERN• Nikhef• Valencia
October 05, 2005 D. Ferrère, RD05 Florence 9
Module assembly resourcesModule 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 ~1h30 + 24h glue curing- Wire bonding ~3h- Detector current check and visual inspection ~15min- Metrology survey ~30min- Thermal cycling ~18h- Metrology survey ~30min- 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 Module assembly procedure
Detector alignment
Assembly with spine
Assembly with hybrid and fanins
Wire bonding
October 05, 2005 D. Ferrère, RD05 Florence 11
Endcap module production Endcap module production Production Started in June 03 and completed in May-June 05
Total : 2377Outer : 1106Middle : 775Inner : 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.
Max production rate:Max production rate:~55 modules/week~55 modules/week
Outer : 94.7%MidL : 94.4%MidS : 88.3%Inner : 87.4%
Average yield : 93.1%
Front side of an outer module
October 05, 2005 D. Ferrère, RD05 Florence 12
Few illustrations of problems found – Part of the learning curve Few illustrations of problems found – Part of the learning curve
Si surface
Teflon surfaceDetector scratches due to
trapped debris into the teflon surface of the transfer
plate.Module is out of detector
current specs!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 resultsElectrical QA results
Out of specs
Good
Good
Out of specs
October 05, 2005 D. Ferrère, RD05 Florence 14
Mechanical QA results Mechanical QA results
Good
Pass
midyF specification inside ± 5 microns mhy specification inside ± 20 microns
Good
Some stats on essential XY alignment parameters
Stereo angle specification 20 ± 0.13 mrad. Defined between front and back detector axis.
Good
October 05, 2005 D. Ferrère, RD05 Florence 15
Mechanical QA results Mechanical QA results
Front and rear detector profile
GoodPass
ZminF
Good
October 05, 2005 D. Ferrère, RD05 Florence 16
Endcap macro-assemblyEndcap macro-assembly
Disk 5A in Module to Disk stand at NIKHEFDisk 5A in Module to Disk stand at NIKHEF
Liverpool: Endcap C & Nikhef: Endcap A
52 outer and 40 inner modulesFront side
40 middle modulesRear side
October 05, 2005 D. Ferrère, RD05 Florence 17
Endcap C disk testing results (Liverpool) Endcap C disk testing results (Liverpool)
Outers : 1576e-
Middles: 1529e-
Inners : 1070e-
Short Middles : 907e-
Average Input noise on the complete
endcap C
Endcap A has similar results so far...Endcap A has similar results so far...
October 05, 2005 D. Ferrère, RD05 Florence 18
Endcap C disk Thermal study (Liverpool)Endcap C disk Thermal study (Liverpool)
Tcoolant= -22 ºC, Tambient= -8 ºC
Average±RMS:Hybrid main point: - 20.8 ± 0.8 ºCDetector-end temp: -18.5 ± 0.6 ºC
Main Point Temperature
-4.0
-2.0
0.0
2.0
4.01
2 3 45
67
89
10
11
12
13
14
15
16
17
18
1920
2122
23242526
27282930
3132
3334
35
36
37
38
39
40
41
42
43
44
4546
4748
4950 51 52
(T. Jones)
October 05, 2005 D. Ferrère, RD05 Florence 19
Endcap statusEndcap 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
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
EC-C cylinder with discs 6 to 9 at LiverpoolEC-C cylinder with discs 6 to 9 at Liverpool
EC-A Disk 8A inserted into cylinder at NikhefEC-A Disk 8A inserted into cylinder at Nikhef
October 05, 2005 D. Ferrère, RD05 Florence 20
Integration and commissioning at CERN SR1Integration and commissioning at CERN SR1
1. The 2 ECs will arrive at CERN in January 06 and March 062. Reception tests: visual inspection, leak test and electrical
tests3. Final SCT assembly4. Integration with TRT5. Combined tests SCT/TRT - 9 SCT discs will be tested together
on 1 sector 6. Installation into the pit foreseen in May and June 06
Cantilever stand with 1 endcapCantilever stand with 1 endcap TRT trolley in aligned positionTRT trolley in aligned positionfor the integrationfor the integration
October 05, 2005 D. Ferrère, RD05 Florence 21
ConclusionsConclusions
• 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 . 2377 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
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 ~ 2.1014 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
Running conditions and featuresRunning conditions and features
October 05, 2005 D. Ferrère, RD05 Florence 24
Module componentsModule componentsHybrid: - 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 m
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 rightsSpine:- 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)
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
0.00001
0.0001
0.001
0.01
0.1
1
10
100
1000
10000
0 2 4 6 8 10 12 14 16 18 20Time (h)
Mo
nit
ore
d v
alu
esTemp (degC)
Icc (mA)
Idd (mA)
Idet (microA)
Noise Occupancy
Electrical QA results 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-assemblyEndcap macro-assembly
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