GLAST. Prototype Tracker Tower Construction Status

Transcription

1 Prototype Tracker Tower Construction Status June 22, 1999 R.P. Johnson Santa Cruz Institute for Particle Physics University of California at Santa Cruz 1

2 Prototype Tracker Tower Configuration 17 Trays, 16 x-y planes, with a total of cm detector ladders. 32 readout sections, all fully instrumented (51,200 channels). Tray Number ladders Pb Thickness Number 4-in Number 6-in each side detectors detectors 17 T: 0 B: 3 3.5% T: 3 B: 3 3.5% T: 3 B: 4 3.5% 35 8 T: 4 B: 5 3.5% 27 4,5,6,7 T: 5 B: 5 25% 120 2,3 T: 5 B: T: 5 B: Total: 17 Total: 126 Total: 135% Total: 260 Total: 222 My corrections to Hartmut s earlier proposal, which had only 16 trays and too many detectors. Proposed test beam trajectories. 2

3 Tracker Mechanical Status Tray components to be assembled at SLAC: 3 16 middle closeouts in hand. Bottom closeout in fab. 3-mil carbon face sheets in hand. 1-mil Al hexcell cores in hand. 4 2-mil Super cores still need to be ordered if we are to have the thick Pb trays. 10-mil C face sheets for thick-lead trays in hand but need trimming. Tray assembly: some delay new gluing fixture is being made, as prototype tray was out of square. First tray due by end of June. Final tray should be assembled by mid July. Other Assembly fixtures: Ladder gluing fixtures, in hand. Ladder work holders, in hand. Back-side ladder prober, in hand. Ladder wire bonding support, in hand. Ladder potting fixture and mask, in hand. Hybrid work holders, in hand. Hybrid burn-in fixtures in hand. Chip gluing guides, in hand. Tray wire-bonding work holders, in progress. Fixtures for attaching hybrids to trays and wire bonding, in progress. Alignment fixture for mounting detector ladders, in progress. Connector mating clamp and special screw drivers, in progress.

4 Tracker Silicon-Strip Detector Status Detectors from 4-inch wafers 300 manufactured. 260 are available for the prototype tower. 52 ladders have been completed with these detectors, including gluing, wire bonding, testing, and potting. Detectors from 6-inch wafers 230 manufactured, 5 rejected and 5 still in Japan for studies. 73 ladders can be constructed, and 18 are completed, with 15 in progress. Detector QC Broken capacitors and shorts detected by probing at Hamamatsu. Global I-V done at Hamamatsu. Visual inspection and global I-V at UCSC/SLAC. Visual inspection, optical survey, and I-V after edge bonding. Global I-V and capacitance measurement on every strip after wire bonding (detects broken capacitors, failed bonds, shorts, opens). Repairs are made at this point, before potting wire bonds. Global I-V after potting and before mounting onto tray. 4

5 Tracker Readout Electronics Status Front-end Readout Chips 5 20 wafers manufactured. 6 wafers tested and then diced good chips (800 needed). Readout Controller Chips 100 chips manufactured. 75 tested (64 good chips needed). Hybrid PC board 40 manufactured (32 needed). 35 loaded with passive components and connectors. 2 loaded with chips and tested. Remainder are at Promex being loaded with chips. Backing plates, in hand. Kapton Detector Bias Circuit 37 manufactured (32 needed). 1 bonded to a prototype tray and hybrid for wire bonding tests. Kapton Cables 2 each of 4 types needed. 10 pieces of one type are in hand. 1 loaded with connectors for testing. DAQ Interface 2nd iteration tracker VME card is being designed by Stanford/HEPL. Shielded twist-pair cable with Glenair Micro-D connectors needs to be manufactured. Interface board from the kapton cables to the twist-pairs is being laid out. It includes LVDS repeaters and noise filtering.

6 Tracker Shielding & Grounding Scheme Analog & digital grounds are separate on the readout chip. Analog ground connects to the chip substrate; digital ground does not. Analog & digital grounds are separate on the hybrids and kapton cables (optionally, a resistor or jumper can be placed between the grounds on the hybrid). Hybrids contain a lot of power filtering and decoupling to ground. The kapton bias circuit includes an analog ground plane between the detector bias and the tray structure. Kapton cables plug into interface cards at the base of the tower. Here analog and digital grounds are tied together and tied to the shield (walls) of the tracker. The interface card amplifies all signals going from the tracker to the VME crates, using LVDS receivers & drivers. Shielded twisted-pair cables connect the interface cards to the VME crates. The shield ties to the ground on the interface card. Ferrite cores on the interface card attenuate common-mode noise coming up from the VME crates. The shields on the twisted-pair cables connect to the VME chassis. Ideally, the shield on the tracker tower should be isolated from the mechanical stage. The tracker digital ground is not tied directly to the VME digital ground. Each have separate ties to the chassis. 6

7 Tracker Shielding and Grounding Scheme Analog & digital GND separate on chips. Only analog GND connects to substrate. Analog & digital grounds are separate on the hybrids and kapton cables. Hybrids include power filtering/decoupling. Analog and digital grounds are connected on the interface cards and there are tied to the tracker shield. Shielded twist-pair cable. Shield ties to GND on interface card and to the VME chassis. 7 VME Tracker Power Tracker TRAY Tracker power comes into front of VME crates. Digital GND separate from VME GND. Analog GND plane in kapton bias circuit shields 100V bias from tray structure. Tower shield ideally should be electrically isolated from the x-y table. Kapton cables have closely coupled power/ground planes for low impedance power transmission. Interface card amplifies signals from tracker to VME, using LVDS chips. Additional power-supply decoupling. Ferrite cores attenuate noise coming from VME crates.

8 Prototype Tracker Schedule Highlights June 30: Complete mounting of chips and wire bonding hybrids. July 8: Complete hybrid gluing fixtures and begin mounting hybrids. July 16: Complete tray wirebonding work holder. July 30: Complete ladder production. August 11: Complete 3 remaining types of kapton cables. August 13: Complete tray mechanical fabrication and detector alignment fixture. Begin mounting detector ladders onto trays. August 25: Finish mounting and wire bonding hybrids to trays. 8 August 31: Complete fabrication of walls, spacers, cable terminations. September 1: Finish mounting detectors ladders. Finish DAQ interface. September 10: Complete stacking of trays and begin tower testing. Survey. Noise scans. Threshold calibration. Bad-channel masking. Cosmic-ray data. Conclusion: the schedule has slipped for mechanical components, but we still have a couple of weeks of contingency.

9 ID Task Name 1 Front-end Readout Chips 5 Readout Controller Chips 7 Fab HDI base plate & cover 8 Fab HDI burn-in base & cover 9 Hybrid PC Board 10 Production 11 Acquire parts 12 Loading passive components 13 Mount IC chips and wire bond 14 Testing and burn-in 15 Kapton Bias Circuit 19 Flex cables and Data Transmission 20 Design & prototype 21 Fabricate first type 22 Design other 3 types 23 Fabrication of other 3 types 24 Tray Assembly 25 Detector Ladder Assembly (4 inch) 26 Detector Ladder Assembly (6-in c 33 Order Closeouts 34 Tray fabrication 35 Fabricate backing plates 36 Fabricate hybrid gluing fixtures 37 Fabricate tray holding fixtures 38 Fab detector alignment fixture 39 Mount electronics and test 40 Glue hybrid to kapton 41 Wire bond hybrid & chips to k a 42 Encapsulate wire bonds & hyb 43 Bend down hybrid & install scr 44 Mount Detectors 45 IV curve of ladders 46 Bond detectors to the tray 47 Wire bond to kapton 48 Electronic test of completed tr a 49 Survey completed trays 50 DAQ Interface 51 Tracker Tower Assembly 52 Fabricate walls, spacers, kevlar ca b 53 Stack Trays and Mount Cables 54 Test and mount walls Project: Date: 6/20/99 June July August September 5/30 6/6 6/13 6/20 6/27 7/4 7/11 7/18 7/25 8/1 8/8 8/15 8/22 8/29 9/5 9/12 9/19 ill[0.05] Industry,Sergei[0.02] eff[0.25],john[0.25],eduardo[0.25],yuko[0.25],gary[0.25] Task Progress Industry Milestone Gwelen[0.5],Bill[0.5],Industry BJ[0.1],SLAC Summary Rolled Up Task Sergei[0.75] Rolled Up Milestone Page 1 Wilko[0.2] BJ[0.1],SLAC Industry,Sergei[0.02] John[0.75] Gwelen[0.1],Alec[0.1] Rolled Up Progress Gwelen[0.15],Bill[0.15] Jeff[0.1] Wilko[0.1] Masa[0.15],Yuko[0.15] Gwelen[0.15],Alec[0.15] Gwelen[0.15],Bill[0.15] Wilko[0.15],Masa[0.15] Gary[0.2] BJ,SLAC John,Eduardo,G 9 Prototype Tracker Construction Schedule