Dipartimento di Fisica Università di Trieste & Istituto Nazionale di Fisica Nucleare (INFN) - Trieste ALICE Vertex Detector focusing on the µstrip layers ALICE-STRIP Trieste: Marco Bregant, A. Borysov, L. Bosisio, P. Camerini, G. Contin, F. Faleschini, E. Fragiacomo, N. Grion, G.-V. Margagliotti, S. Piano, I. Rachevskaia, R. Rui Marco Bregant Vertex05 - Nikko, November 2005 Muon Spectrometer L3 magnet HMPID TOF TPC TRD PHOS Dipole magnet Dipartimento di Fisica Inner Tracking System Requirements: •Vertex resolution < 100 μm (Charm, Hyperons) •Acceptance down to 100 MeV/c •Improvement of pT from outter tracker •Particle densities up to 80/cm2 •Low mass (γ conversion, multiple scattering) Marco Bregant Vertex05 - Nikko, November 2005 Dipartimento di Fisica Inner Tracking System 2 layers of Silicon Pixel Detectors R=3.9 cm; 7.6 cm dNch/dx2~ 80 particles/cm2 2 layers of Silicon Drift Detectors R=14.9 cm; 23.8 cm dNch/dx2~ 5 particles/cm2 2 layers of Silicon Strip Detectors R=38.5 cm, 43.6 cm dNch/dx2~ 1 particle/cm2 Marco Bregant Vertex05 - Nikko, November 2005 Silicon Pixel Detector Dipartimento di Fisica • 60 staves, 240 modules • 40960 chs. per module • cell size (r,z): 50 x 425 µm2 • spatial resolution (r) 12 µm • spatial resolution (z) 100 µm Marco Bregant Vertex05 - Nikko, November 2005 Silicon Drift Detector Dipartimento di Fisica • 36 ladders, 260 modules • 2 x 256 chs. per module • cell size (r,z): 294 x 150 µm2 • spatial resolution (r) 35 µm • spatial resolution (z) 23 µm Drift Drift sensor active area: 7.02 x 7.53 cm2 Marco Bregant Vertex05 - Nikko, November 2005 Silicon Strip Detector • 72 ladders, 1698 modules • cell size (r,z): 95 x 4000 µm2 Ladder, • spatial resolution (r) 20 µm top • spatial resolution (z) 830 µm SSD module (after folding) Dipartimento di Fisica Ladder, bottom Marco Bregant Vertex05 - Nikko, November 2005 SSD module Dipartimento di Fisica 40 mm 42 mm Hybrid Sensor 72 75 mm mm 6 µcables 6 chips Marco Bregant Vertex05 - Nikko, November 2005 Parts forming a module Sensor • n-type silicon • 300 µm thick • double sided • Stereo angle: 35 mrad p: 7.5 mrad n: 27.5 mrad • integrated AC decoupling Dipartimento di Fisica P 768 strips/side, 96 µm pitch N Marco Bregant Vertex05 - Nikko, November 2005 Parts forming a module HAL25 chip Dipartimento di Fisica CMOS .25 µm process, rad-hard ~11 mm mixed analogue/digital chip 128 input channels ±14 MIPs dynamics 1.4 2.2 µs adjustable shaping time JTAG programmable powered @2.5 V thinned down to ~150 µm ~4 mm Marco Bregant Vertex05 - Nikko, November 2005 Parts forming a module µcable to sensor 2.4 mm 11 mm Dipartimento di Fisica Aluminium traces (14 µm) on polyimide (10 µm) support TAB frames for easy handling Developed & supplied by the Ukrainian group to subhybrid chip Marco Bregant Vertex05 - Nikko, November 2005 Parts forming a module Dipartimento di Fisica SubHybrid Bottom view Made in UA aluminium/polyimide flex cooling blocks tail: fits in a ZIF connector for tests carbon-fibre stiffener SMD resistors SMDcapacitors Top view Marco Bregant Vertex05 - Nikko, November 2005 Module assembling scheme Dipartimento di Fisica Marco Bregant Vertex05 - Nikko, November 2005 Assembling flowchart Dipartimento di Fisica Sensor Chip Tabbed chip µcable Test Hybrid Tabbed chip µcable 6X half module Test Sub-hybrid 6X Chip Test Test Hybrid Sub-hybrid Test module Test to ladders Marco Bregant Vertex05 - Nikko, November 2005 How to do it? ... in Trieste Dipartimento di Fisica Production of 1700 modules split in three locations: Helsinki: entirely produces on-site Strasbourg: entirely produces on-site Trieste: produces in collaboration with an external manufacturer (840 modules) 840 modules: 1700 hybrids, 10000 tabbed chips, ... ~30000 tests ...a tiny mass production • process optimization (including custom jigs): • on-line quality control: fast & reliable tests for immediate feedback Marco Bregant Vertex05 - Nikko, November 2005 Step 1: chip + µcable Dipartimento di Fisica bonding mask TAB-Frame frame holder bonder chip holder positioning system (4 axis) Marco Bregant Vertex05 - Nikko, November 2005 Step 1: chip + µcable Dipartimento di Fisica ...aligning and automatic TAB bonding Marco Bregant Vertex05 - Nikko, November 2005 Step 2: hybrid assembling Dipartimento di Fisica Jig for hybrid assembling Marco Bregant Vertex05 - Nikko, November 2005 Step 2: hybrid assembling Dipartimento di Fisica - 6 tabbed chips are aligned and glued to the subhybrid - automatic TAB bonding of the 6 tabbed chips to the subhybrid Marco Bregant Vertex05 - Nikko, November 2005 Dipartimento di Fisica Marco Bregant Vertex05 - Nikko, November 2005 Steps 3&4: module assembling Dipartimento di Fisica Bottom side Top side Marco Bregant Vertex05 - Nikko, November 2005 Module made Dipartimento di Fisica Marco Bregant Vertex05 - Nikko, November 2005 Test & validation Dipartimento di Fisica • a test at each step • production in three sites (including industry) √ same electronics √ same automatic test Marco Bregant Vertex05 - Nikko, November 2005 Noise&gain tests Dipartimento di Fisica Depleted Module (p side) noisy region noise: ~2.5 a.u. summary signal ~ 900 a.u. in response to ~10MIPS from chip internal pulser bad channel Marco Bregant Vertex05 - Nikko, November 2005 Search for short-circuited chs. Dipartimento di Fisica ch. n is pulsed ch. n+1 is read summary Marco Bregant Vertex05 - Nikko, November 2005 The test summary Dipartimento di Fisica In the right pane: - all the useful information, i.e. - module serial number - chip serial numbers - a led for each test (green: 0K; yellow: minor problem; red: major failure - the list of: - open channels - short-circuited channels - broken AC channels Test duration: ~ 10 minutes - the final quality (= 100 defective channels) green: OK! ALL is saved in an ASCII report file Marco Bregant Vertex05 - Nikko, November 2005 The assembling of SSD modules Conclusions Dipartimento di Fisica • an assembling system was designed to produce the SSD module of ALICE • production goes smoothly ahead • typical rates (yields) are 100 tabbed chips/day (88%) 10 hybrids/day (97%) 20 modules/week (92%, 85% at the first trial) • a total amount of number of 1000 (out of 1700) modules were so far assembled in the three production sites Marco Bregant Vertex05 - Nikko, November 2005 Dipartimento di Fisica Additional slides Marco Bregant Vertex05 - Nikko, November 2005 Testing on the beam Test beam Hall at CERN Dipartimento di Fisica 5 modules have been tested with a π beam (7 GeV) Marco Bregant Vertex05 - Nikko, November 2005 Test beam results N side S/N ~ 45 Dipartimento di Fisica P side S/N ~ 60 Marco Bregant Vertex05 - Nikko, November 2005 Spatial resolution Dipartimento di Fisica z resolution r resolution design: 20 µm design: 830 µm measured: 20 µm measured: 975 µm Marco Bregant Vertex05 - Nikko, November 2005