PixelAtsushi Taketani

RIKENRIKEN Brookhaven Research Center

1. Overview of Pixel subsystem

2. Test beam

3. Each Components

4. Schedule

5. Summary

2

Full ladder

~4mm

Pixel bus

Pixel sensor modules

Pixel stave (with cooling)

Pixel detector = inner 2 layers of VTX1st layer: 10 full pixel ladders = 20 half ladders = 40 sensor modules2nd layer: 20 full pixel ladders = 40 half ladders = 80 sensor modules

Pixel DetectorPixel Detector

SPRIO

57mm (32 x 4 pixel)13mm256 pixel

Sensor module 50m x 425m

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Specification• Collision Rate ~ 10MHz -> Timing Resolution < 100nsec• Trigger Rate Max 20KHz• Occupancy < 1% for pixel detector • Pixel size 50 * 425m2 • Tracking Resolution 50micron for displacement • High precision at mechanical construction ~ 25 micron for internal• Material Budget ~ 1% of radiation length

• Technology: Pixel detector developed for ALICE experiment at LHC.

• Budget: – RIKEN : Ladders and Front End Module– DOE: Mechanical and infrastructure– Ecole Polytechnique :SPIRO board

44

PIXEL (Sensor and Readout)

Pixel size( x z ） 　 50 µm x 425 µmSensor Thickness 200mr = 1.28cm, z = 1.36 cm (Active area)256 x 32 = 8192 channel / sensor4 chip / sensor4 sensor / stave

Readout by ALICE_LHCB1 chip

• Amp + Discriminator / channel

•Bump bonded to each pixel

•Running 10MHz clock ( RHIC 106nsec )

•Digital buffer for each channel > 4sec depth

•Trigger capability > FAST OR logic for each crossing

•4 event buffer after L1 trigger

55

PIXEL (Sensor and Readout)

Readout by ALICE_LHCB1 chip

• Amp + Discriminator / channel

•Bump bonded to each pixel

•Running 10MHz clock ( RHIC 106nsec )

•Digital buffer for each channel > 4sec depth

•Trigger capability > FAST OR logic for each crossing

•4 event buffer after L1 trigger

66

Pixel detector ladder• Sensor module consists of 4 ALICE Pixel readout chips

Bump-bonded to silicon sensor

Sensor

Thermo plate + coolingALICE LHCB1 chip

SensorSensor Module

77

Pixel detector ladder• Sensor module consists of 4 ALICE Pixel readout chips

Bump-bonded to silicon sensor

Sensor

Thermo plate + cooling

• One readout unit, half stave, made from two sensor modules

ALICE LHCB1 chip

SensorSensor Module

88

Pixel detector ladder• Sensor module consists of 4 ALICE Pixel readout chips

Bump-bonded to silicon sensor

Sensor

• Half stave is mounted on the support structure

Thermo plate + cooling

• One readout unit, half stave, made from two sensor modules

ALICE LHCB1 chip

SensorSensor Module

99

Pixel detector ladder• Sensor module consists of 4 ALICE Pixel readout chips

Bump-bonded to silicon sensor

Sensor

• Half stave is mounted on the support structure

Thermo plate + cooling

• Pixel BUS to bring data out and send control signal into the readout chip is mounted on the half stave

Half stavePixel BUS

Data

• One readout unit, half stave, made from two sensor modules

ALICE LHCB1 chip

SensorSensor Module

1010

Pixel detector ladder• Sensor module consists of 4 ALICE Pixel readout chips

Bump-bonded to silicon sensor

Sensor

• Half stave is mounted on the support structure

Thermo plate + cooling

• Pixel BUS to bring data out and send control signal into the readout chip is mounted on the half stave

• Each detector module is built of two half staves,read out on the barrel ends

Half stavePixel BUS

Data

• One readout unit, half stave, made from two sensor modules

Full stave

22cm

1.4cm

ALICE LHCB1 chip

SensorSensor Module

1111

Bus structure

Power 50 m Al

GND 50 m Al

• 6 layers structure• GND, Power and 4 signal lines

Signal 2; (Vertical line)line connected withpixel chip with wire bonding

Signal 4; (for manufacture reason)

Signal-4 3 m Cu

Signal-3 3 m Cu

Signal-2 3 m Cu

Signal 1; (for Surface Mount Device)Signal-1 to Signal-4are connected with through hole

Signal lines; 60 m pitchMaterial Budget; Total ~ 0.26 %

Final configuration

Signal-1 3 m Cu

Signal 3; (Horizontal line) send signal to Pilot Module connected with vertical line with through hole

Thermo-plateSensor module

Wire bonding

Al Power Al GND

Through hole

Signal layer

Total 188 lines

25cm long

1.4cm wide

1212

Pixel Readout Overview

Half stave

11cm

60cm

Bus (25cm ) + Extender (<35cm)

13

Major components StatusComponent Status #delivered (needed)

Sensor Module Ordering new module and rework

69 good one (128)

Bus Under Production 5 sets of R/L (64)

Extender FPC production doneUnder SMD parts population

80 (80)

SPIRO board Under Production Summer 2009(66)

FEM Under production Ready by end of Aug.(33)

Stave Under production 5 are tested and delivered(32)

Ladder Assembly

Production started 1st :manual assemble2nd : using assembly fixture(32)

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Test beam at 120GeV Proton

Stripixel Pixel

Proton

FERMILAB Meson Test area

120 GeV Proton

5-30mm beam spot

4.5 sec spil per 1 min.

2×1010 proton / spil

Independent DAQ for Pixel and Stripixel.

Using trigger scintillation counters

Stripixel

3 Prototype ROC

Trigger: Beam defining Scinti.

DAQ : SVX4+ ROC+RCC

Pixel

3 Prototype pixel ladder

Trigger: Scinti * FAST_OR (3layer)

DAQ: Prototype Readout + PHENIX DAQ

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Pixel performanceResidual

res = 6.1m res = 57m

Row direction Column direction

Residual [m] Residual [m]

coun

t

coun

t

Intrinsic resolution row : 14m column : 152m

3

1

2)(i

iXFit

Un-convolute

Fit include all 3 layers hit position

Multiple scattering effect

16

Sensor Module Status

• We need 120 sensor module for 30 ladder plus spares.

• 69 Useable Class I sensor Modules.• 51 Class III sensor module will be

reworked until September 2009 and probed for 2 months.

• 55 brand new sensor module will be purchased under paper work going.

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Class I 702chipsClass II 175 chipsClass III 538chips

•We need 271 chips for reworking and new sensor modules.

Readout Chip

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Readout Bus

Sensor

10cm

Bus

Extender

Total < 60cm (70cm)

Line/space are 30 /30 micron

Bus and extender are connected by the fine pitch connectors.

Type

Bus: Left and Right

Extender: 34cm long

30cm long

29cm long

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Bus Production Status

• All process for bus productions has been established.

• 40 Left and 40 Right plus are needed.• 5 set of Bus was fabricated as pre-

production.• Left version is fine for production, Right

version is under confirmation. • 1st Production is starting.

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Extender

• 80 extenders are needed in total.• 5 extender was produced as pre-

production and confirmed with ladder, SPIRO and FEM.

• Production of total 80 extender was done except trivial surface mount connecters implementation.

21

Stave• Finalized the specification on Feb 2009.• 32 staves plus spares are needed.• LBNL delivered to RIKEN 5 staves.• 20 staves are waiting for survey.• Remainders will be delivered end of June 2009.

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Spread glue on stave with mask

take 0.2 hourswill be reduced measuring point

Paint glue using mask and manual paddle.

Glue thickness are well controlled 80 micron +-10micron

Assembly procedure: (1) gluing

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Assembly procedure : (2) aligned sensors on stave

X[mm]

Y[m

m]

+-10　micron

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Assembly procedure: (3) wire bonding

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Assembly procedure: (4) Encapsulation of wire

Wire vibrates in magnetic field due to the intermittent current associated with level 1 trigger and may break

stavesensor

Bonding wire

barrier

Potting glue 1mm

No encap

～ 5.9KHz

Resonance

26

Ladder assembly Status

• Prototyping is completed.• Production is started

– Ladder 1 : Class II sensors and real stave/bus Manual assemble for fall back solution. Finished gluing stave-sensor-bus. Under wire bonding– Ladder 2 : Class II sensors and real stave/bus Sensors are glued on the stave by using

assembly fixtures. Bus will be glued by manually.

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•Multiplex data from ladder and control readout chip

•Reference voltage

•Serial data transmission to FEM by optical link

•Radiation hard for all components.

•Low jitter crystal for high speed link.

•Voltage regulator for ladder.

•Production just started and will be finished before 2009/08.

SPIRO Board by Ecole Polytechnique

Front End Module by Stony Brook University

•Receiving data from SPIRO and transmit to PHENIX DAQ with specified format

•VME base board for slow control/diagnostic.

•Not Radiation hard.

•1st production board is under exhaustive tests.

•All boards are under assembly and will be ready by end of 2009/08.

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ScheduleSensor module

Ladder Assembly

Readout Electronics

•SPIRO board: Production done before 2009/08

•FEM : Under production and tested until 2009/08

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Issue

• Sensor module reworking and additional production.– Long lead time. We already discussed with

VTT/CERN.– May impact schedule.

• Ladder assembly had some technical difficulties and has been resolved.– Manual gluing for bus is established.

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Summary

• Production of pixel ladder has been started.– Technical issues on the ladder assembly was

resolved.– More sensor modules are ordered.

• Readout electronics will be ready by 2009 Fall.