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Pixel Detector Status. Vaclav Vrba Institute of Physics , AS CR, Prague. Layout of the talk. Mechanics and services System tests Rad-hard electronics Module production Sensors Schedule. Mechanics and services. The Pixel Support Tube (PST) has passed PRR on Feb03
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Pixel Detector Status Vaclav Vrba Institute of Physics, AS CR, Prague Vaclav Vrba, Institute of Physics, AS CR
Layout of the talk • Mechanics and services • System tests • Rad-hard electronics • Module production • Sensors • Schedule Vaclav Vrba, Institute of Physics, AS CR
Mechanics and services • The Pixel Support Tube (PST) has passed PRR on Feb03 • it is in production • it should be delivered on schedule (Jan05) to be installed with the barrel ID PP1 PP0 A 7m long object PST (half length shown) Forward C Barrel Forward A PST Flanges Vaclav Vrba, Institute of Physics, AS CR PP1 End Plug
The global pixel support has been delivered; • The local supports (staves and sectors) have accumulated some delay, sectors because of change in pressure specs (cooling) and staves because of several minor problems at start-up. Not on critical path. • Even if the number of staves produced to date is small (9), the yield is very high (9/9) and the production of parts is now going on well. Vaclav Vrba, Institute of Physics, AS CR
Services topology and names (not to scale) PP3 Located on the service platform. Only a preliminary layout exist. Power and HV cables Type III - Twisted Pair Cables (~ 140 meters) Voltage regulation box PP2 Muon Chambers Cooling, Signal & Optical Readout Power and HV cables Type II - Twisted Pair Cables (~ 9 meters) Tile Cal PP2 Lar Cal PP2 for cooling Cryostat inner bore (PPF1) Z = 0 PP1 Beam Line PP0 Pixel Vaclav Vrba, Institute of Physics, AS CR
Service Panels FDR in June ‘03 PP0 Patch Panel Beam Pipe Support Structure Pixel Detector Not Shown Beam Pipe Beam Pipe Support Structure Service Panels Vaclav Vrba, Institute of Physics, AS CR PP1 Patch Panel(pipes and cables not shown!)
PP1B • More work than foreseen around services, • FDR has been passed recently and • PRR will be by within 2003. • Cables and fibers (PP1outward) must be installed in Fall 04, so procurements have to begin (very) soon. • PP0 & PP1 (US deliverables) are very crowded and PP1 (the interface to be open first when we install/deinstall) should also afford issues related to moisture, activation high-P coolant and gas and electrical seals. • Optofiber bundles (PP0PP1 and PP1US15) have been designed and are about to go for tender (F,G and Cz) • Type 2 cables (Italy deliverable) have been mostly defined, still missing some connector compatibility check-up at PP1 (mock-up ongoing), then ready for tender • Type 3 cables (F, G, I, and US) mostly defined, Work in progress… toward IP PP1A Vaclav Vrba, Institute of Physics, AS CR
System tests • System tests show that operation of modules is not affected by LV multiplicity (1 LV source going to N (16) rad-hard voltage regulators, then from 1 regulator to 1 module). This measurement has been done with realistic services (i.e. cable lengths and x-sections ). • threshold (~3ke-) and noise (~180e-) are the same for LV multiplicity 1 and mult. 6 • right histograms indicate difference between the two cases (Dthr=17e-, Dnoise=6e-) Vaclav Vrba, Institute of Physics, AS CR
Voltage regulators boards have been designed, built and tested using the rad-hard chip . • this will be placed in the PP2 box (close to m-chambers) some 12 m (of cable) away from the detector itself. • few boards for system tests built • all regulators needed for the final system (5500) will be purchased this year. Vaclav Vrba, Institute of Physics, AS CR
System tests (with regulators and final cables) have been done both on: • realistic set-up (i.e. 6 modules on a sector support) in lab • under irradiation (7 modules on C-C support irradiated to >30 Mrad) at PS. Vaclav Vrba, Institute of Physics, AS CR
Rad-hard electronics • FE&MCC FDR passed (810 Oct 02) • Submissions received back in mid May (FEI2) and on June,6 (MCCI2) • many improvements correcting limitations, but… • one fault in each design does not allow to use them in the planned “advanced production”, this will squeeze our schedule (see later). • FEI : the improvements • 7-bit (was 5-bit) threshold on each channel, works fine and very linear • native threshold dispersions ~650e- (was ~1000e-) and 25e- after tuning • autotune circuitry (new feature) allows to tune to ~50e- in 30”/module (instead than 2h/module if an external PC is used). • bias compensation circuitry eliminates FEI1 non-uniformities • hit-bus scaler to find “hot” pixels (and later kill them) works fine • yield above 90% (on 1 wafer), encouraging as we changed IBM foundry from FEI1 to FEI2. Vaclav Vrba, Institute of Physics, AS CR
FEI: the problem • chip operates up to ~1.7V, then the register loading stops to operate correctly and there are errors in writing some configurations. • this has been traced back to verify conditions in the command and global shift registers • those registers have been triplicated (+ majority vote) to reduce the SEU rate in order to safely operate the b_layer. • in doing so, the size of the registers became much larger. Voltage at which configuration of FEI2 starts failing FEI1 FEI2 Vaclav Vrba, Institute of Physics, AS CR
FEI2: the problem (cont.) • The clock distribution was not optimized for the SEU tolerant layout. • problems could be traced to some section of the shift registers and those appear to have clock lines sensibly longer than data lines, thus supporting the race hypothesis (a late arriving clock on one section of the SR does not strobe the correct bit, but the one just following) • FEI2: the fix • Quick fix: route manually the ck against the data (casuality will avoid race conditions) this change has been done on 6 back-up wafers (back Aug.15)=FEI2.1 • Final fix: use proper simulation tools for the clock tree optimization, this may be necessary (submit Oct.2, wafers back at Nov. 26)= FEI3 (start design NOW) How the clock moves through one SEU tolerant shift register. One place where the error happens is indicated with yellow arrows Vaclav Vrba, Institute of Physics, AS CR
Module production • Bump-bonding and flip-chip • 2 syncronized tenders with same specs went out (Uni Bonn and INFN Genoa). • INFN tender is over with the choice of AMS (1500 modules), UniBonn will be over soon and likely to end-up with IZM (600 modules). Two bump sources are critical to meet the schedule, they also are a safety measure against one firm loosing interest. • In the meantime modules produced with FEI1 (~40 per firm) allows to detect the most common yield losses and find corrective actions. PDB is precious for this trace back. Vaclav Vrba, Institute of Physics, AS CR
Production rate still low, but firms (and us) not yet in production mode. • Bare modules produced by firms, flex module produced in labs (dressing and testing bare modules) Vaclav Vrba, Institute of Physics, AS CR
some reworking may be necessary to keep the yield up (even if we operate on KGDs) as yield_module = (yield_chip)16 • techniques for reworking in hand both for In and SnPb bumps and results ok (even if further parameter tuning for In is necessary to go below 30 defects/reworked chip) Tool per reworking In bump (AMS) Venturi Vacum Pump Z-Axis IZM reworked Modulo Bonn-5 Pickup tool with load cell Hot plate with Peltier cell X-Y stage Reworked chips Peltier Power supply Motion control Milano Vaclav Vrba, Institute of Physics, AS CR
Flex • 1st 1000 flex delivered by Dyconnex. Quality is good, bow is small enough not to cause problems. • Starting-up loading now, first sample of 50 indicate chemical cleaning problems and solder on bond pads in some cases. These must be solved before going into mass production, but believed to be easy. Vaclav Vrba, Institute of Physics, AS CR
Sensor production and testing Prague deliveries Udine Dortmund Vaclav Vrba, Institute of Physics, AS CR
Sensors • Sensors • CiS production of 600 good tiles (all tested) done, next 400 delivery to resume next month after factory moved to a new site and restarted. • Tesla recently qualified for the mass production of pixel sensors for ATLAS. Production will start in January 04; end of production in summer 05. • We got a positive answer from both vendors for our request to extend the option for buying more sensors up to Feb 05. Vaclav Vrba, Institute of Physics, AS CR
Schedule • Advanced production was supposed to happen from summer to Dec03 • this would have allowed a smooth start-up of all the (firm+lab) activities related to module construction • would have also allowed to build a couple of disks at least, thus reducing the pressure on the forthcoming “real” production • due to the delay of electronics we may now only hope to begin a smaller advanced production with the 6 wafers of FEI2.1 this may at most give 1 disk plus the necessary modules to keep going with the qualification of the stave production labs. • all that translates into: • delivery of the pixel system delayed by 2 months • more compact production schedule with sharper start-up curve (and therefore more risk) • in the following are shown some details of the electronics and module schedule. Vaclav Vrba, Institute of Physics, AS CR
Electronics schedule Can this be anticipated? Vaclav Vrba, Institute of Physics, AS CR
Module schedule 8w from wafers to dies Xmas! Assumes 4w from wafer delivery 2m delay Vaclav Vrba, Institute of Physics, AS CR
Conclusions • Achieved technical progress is excellent, it has been demonstrated that pixels can really meet all LHC requirements, • Problems in electronics are not very serious and can certainly be corrected in the timescale indicated. • The sensor production is well in schedule – a half of the production is ready, end of the production in summer 2004. • Due to the present development with FE chips only in Spring04 we will be in position to safely extrapolate to the “ready to install” day. Vaclav Vrba, Institute of Physics, AS CR