CMOSBiCMOS process capabilities

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Celebrating LHCb Industrial Award Micronova,
November 7, 2008
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LHCb Industrial Award
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VTT Employees (Past and Present ) Who Have
Contributed to LHCb

• Ilkka Suni
• Jorma Salmi
• Sami Vähänen
• Hannele Heikkinen
• Harri Pohjonen
• Satu Savolainen
• Kristiina Rutanen
• Mervi Hämäläinen
• Jaakko Salonen

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LHCb Award Ceremony at CERN Oct. 20, 2008
L to R Andrej Golutvin, Ilkka Suni, Sami
Vähänen, Ken Wyllie, and Werner Witzeling
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Ilkka Suni Addressing Distinguished Audience at
Awards Ceremony at CERN
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LHCb Experiment

• B is for beauty.
• At CERNs Large Hadron Collider, beams of protons
  will be accelerated close to the speed of light
  and smashed together, recreating the conditions
  that existed when the Universe was a hundredth of
  a billionth of a second old.
• Although absent from the Universe today,
  particles known as beauty quarks were common in
  the aftermath of the Big Bang, and will be
  generated by the LHC, along with their antimatter
  counterparts, anti-beauty quarks.
• 'B' and 'anti-b' quarks are unstable and
  short-lived, decaying rapidly into other
  particles. By comparing these decays, it may be
  possible to gain useful clues as to why nature
  prefers matter over antimatter.
• By harnessing the power of the LHC, the LHCb
  experiment will be able to study many more b and
  anti-b quark decays than ever before.

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Silicon Pixel Detectors for LHC
Mont Blanc
LHCb Experiment Site (F) VTT has delivered
830 flip chip bonded pixel detectors for the LHCb
Ring Imaging Cherenkov Detector.
L'Aéroport International de Genève
Lac Léman
ATLAS Site
LHC Large Hadron Collider
ALICE Experiment Site (F) VTT has delivered
over 500 '1x5' flip chip bonded pixel detectors
for the ALICE SPD.
CMS Site
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LHCb Large Hadron Collider beauty
experimentMain accelerator tunnel 27 km
long.100 m underground.
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LHCb Readout Chip

• LHCb readout
• 0.25 mm 6-metal CMOS ASIC (IBM).
• Radiation-hard design.
• Readout Wafers 200 mm x 725 mm.
• Bumps (pixels)/chip 8,192
• (32 colums x 256 rows).
• 13 million transistors
• Power consumption 800 mW _at_ 1.8 V

Rectangular Pixel Pxel Size 50 mm x 400 mm
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Wafer Bumping and Flip Chip Assembly
ALICE SPD 1x5 ladder
Flip Chip
Silicon sensor
LHCb single assemblies
Readout electronics
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Bumped LHCb Readout Sensor Chips
Readout chips
LHCb detector mounted on ceramic carrier for
testing
Sensor chips
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LHCb Readout Bumped Using High-Melting Point
Pb-Sn Solder

• Use of high-melting point (low-tin) solder alloy
  bumps on readout.
• Use of eutectic SnPb solderable pads on Si pixel
  detector.
• Sn 14 - Pb 86 solder composition in bonded
  assembly.

LHCb Solder bump after reflow
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Ultrafine-Pitch Flip Chip Bonding
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Post-bonding Assembly Reflow

• Assembly reflow done for tack-bonded
  assemblies.
• Reflow done in oxide-reducing Ar/formic acid
  ambient to enhance wetting and to enable
  self-alignment.

Assembly reflow
Flip chip tack bonding
Self-alignment in Assembly Reflow
Self-alignment
Alignment
Contact
Wetting
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Imaging Cherenkov Ring with LHCb Assembly
High-temperature HPD assembly (1) ceramic
carrier adhesive 10 min _at_ 400C, (2) HPD vacuum
tube bake-out 3 h _at_ 300C (6-hour up down ramp
times).

• High-quality solder joints characteristics of
  flip chip assembly did not change during HPD tube
  manufacturing (high-vacuum bake-outs).

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Two LHC Experiments
LHCb
ALICE
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Hybridized Pixel Detectors
ALICE ITS 240 5x1 SPD modules (10 million
pixels).
LHCb RICH 830 single assemblies for HPD anodes.
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Ring Imaging Cherenkov HPDs

• Hybrid photon detectors for low noise detection
  of Cherenkov radiation.
• Pixel anodes mounted on a ceramic carrier inside
  a vacuum tube.
• New high lead flip chip process developed for
  tube assembly.
• VTT delivered a total of 830 production
  assemblies.
• More than 500 HPDs assembled into RICH1 and
  RICH2 detectors.

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LHCb RICH HPD
HPD Hybrid Photon Detector
RICH Ring Imaging CHerenkov counter
Readout/Detector Flip Chip Assembly
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LHCb Detector Schematic
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LHCb Pit
RICH1
RICH2
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Pixel HPDs in RICH
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More on LHCb Experiment

• http//lhcb-public.web.cern.ch/lhcb-public/

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Special thanks to Ilkka Suni, Sami Vähänen, Jorma
Salmi, and Ken Wyllie for contributing material
for this presentation.