C. Haber 6-Mar-08

Integrated StaveElectrical/Mechanics/Cooling

UpdateMarch 6, 2008

C. Haber 6-Mar-082

6 x 3 cm, 6 chips wide

10 x 10 cm, 10 chips wide

1 meter, 3 cm strip, 30 segments/side192 Watts (ABCD chip), ~2.4 % Xo + support structure

1 meter, 2.5 cm strip, 40 segments/side200-250 Watts (@0.25 W/chip) ~1.9 – 2.2 % Xo + support

Stave-07

Stave-06

60 cm, 9 cm strip, 6 segments/side

Stave-08

Prototypes and Designs

Build and test

Study

C. Haber 6-Mar-083

Introduction

• With regard to the Single Sided approach, the arguments about simplicity, material, and cost, have been presented already.

• This effort is tightly coupled to the alternative powering efforts, in particular serial, but we would hope to include aspects of DC-DC as well, in the future.

• We are concerned that in a large, for example, serial system, grounding, shielding, and modularity issues may be critical

• Our goal, therefore, is to build and test a realistic scale system early-on, and include enough options and flexibility to be useful.

• With regards to the above, and also to assembly and production issues, we want to confront as much of the full problem as possible, now.

C. Haber 6-Mar-084

Aspects

• Status overview

• Components

• Fixtures

• Electrical testing

• Additional critical tests

• Alternatives

C. Haber 6-Mar-085

Issues From Valencia

• Progress on testing and fabrication of Stave-07

• Irradiation of hybrids glued directly on silicon surface

• Thermal performance of bridged hybrid

• Planning for Spring 2008 module review

C. Haber 6-Mar-086

Status Overview

• Central goal is assembly and test of Stave-2007. Confront assembly, test, and measurement issues relevant to future

• Have built ~30 hybrids , and operated 5 in a serial chain with good performance

• Have built and are studying 4 modules with hybrid on the silicon and 1 “reference” module with hybrid off the silicon

• Effort on gluing and alignment procedures implicit in module building

• Bus cable has been fabricated– Extra clock lines have been added to allow options for clock

distribution included 1 clock for 30 module or 1 clock for 10 modules

• All components required to build Stave-2007 are in-hand.• Bridged hybrid has been further simulated and clarified• Irradiation plans underway

C. Haber 6-Mar-087

Components

• 3 cm p-in-n sensors based upon ATLAS-98

• Fanouts – from SCT

• 6 ABCD chip, serial powered ceramic hybrid– Approx 30 built and tested with good yield

• Stave mechanical core– Ready and waiting

• Assembly fixtures– In use

• Interface pc boards

• Bus cable fabrication complete, delivered

• DAQ system (NI-PXI card + LV software)

• Power supplies

C. Haber 6-Mar-088

6 ABCD BeO Ceramic Hybrid

• ~30 fabricated and tested

• Yield is (surprisingly) good!

• Represents a density maxima

• Includes HV-GND options within serial scheme

• Analog performance is right-on-target

• Ceramic flatness is engineered by printing but not perfect.

Groundlayer

Powerlayer

Analog power

Digital power

Analog current

LVDS section Serial power section

C. Haber 6-Mar-089

Hybrid HV-GND options

HV in

HV Gnd

AV-MOD

AG-MODAC gnd

C. Haber 6-Mar-0810

Fixtures for Assembly AND Test

C. Haber 6-Mar-0811

Module Assembly and Test Fixture

volve asingle fixture for assembly, bonding, inspection, and test.

C. Haber 6-Mar-0812

Bus Cable Signal Layout

Serial current linkSerial currentreturn

HV distribution

Clock &Commandlines

DataReadout1/hybrid

Port Card

C. Haber 6-Mar-0813

Bus Cable: Shielding

l foil, 50 um thick, canbe grounded to each hybrid

C. Haber 6-Mar-0814

DAQ

C. Haber 6-Mar-0815

HV Supply for 30 step serial system

• GENH 150-5

• 0-150 V

• 0-5 A

• Constant current or constant voltage mode

• 30 step ABCD system will require ~120 V and 0.75 A.

• Supply is in-hand, preparing to test using hybrid test board daisy chain and then bus cable

C. Haber 6-Mar-0816

Electrical testing

• Hybrid performance– verified

• Serial powering with increasing drops– 5 OK, new supply allows full 30 drop test

• Data transmission in a multi-drop system– 5 test board system OK, now confront full bus cable, Santa Cruz

• Module performance– In progress, see slides

• Grounding and shielding on a stave– upcoming

• Effect of glue

• Radiation effects

C. Haber 6-Mar-0817

Module Performance

• Reference module (hybrid off silicon) shows excellent performance, low leakage, low noise, and correct gain

• Assembly of 4 “hybrid-on” modules has been a learning curve and not without incident

• One module shows good leakage and analog performance while the others have larger currents.

• Adopting additional safeguards and procedures in order to control performance.

• Note – for Stave-06 multiple good “glued-on” modules were built and characterized

Input noise @ 2fc

ref

Glued on

C. Haber 6-Mar-0818

continued

Ref Glued on

C. Haber 6-Mar-0819

Additional Critical Tests

• Glue studies– Once we get the module assembly process under-control, plan a

systematic glue testing program

– Temperature cycling

– Load with thermal filler (BN)

– …

– Needs to be repeated on n-in-p sensors as well.

• Irradiations– See slides

• Bridged hybrid– See slides

C. Haber 6-Mar-0820

Irradiation plans

• Irradiations are in planning phase both at BNL and LBNL• BNL is looking at BNL, Boston, and Los Alamos sites• LBNL would use on-site 55 MeV protons• Hope to have first runs in the next few months• A key set of questions here are what would constitute a

meaningful measurement?– Conditions– Particle type– Specifics of detector design

• One point of view holds this to be purely a surface issue which could be addressed with a gamma source…opinions?

• Ultimate skepticism?• Note: CDF and D0 have run with glued hybrids for >5 years

C. Haber 6-Mar-0821

Alternatives

• The bridged hybrid has always been the ATLAS preference

• FEA indicates reasonable performance for this alternative

• However the ultimate material reduction would come from reducing the hybrid substrate even more– A kapton flex or other thin film hybrid with essentially no substrate,

glued directly on the silicon, would minimize material

– We are not wed to the ceramic technology – it was convenient and low risk for us.

– We would be happy to see others pick this challenge up and move it forward!

– Since the 6 chip serial hybrid is known to work electrically, we are importing the layout into a fine-pitch printed board design which could be adopted for flex or other etched approaches. We can make this available to the community.

C. Haber 6-Mar-0822

FEA Models of Bridged Hybrid - I• Since the Valencia meeting we have completed FEA analysis of basic

thermal performance with bridged hybrid• Multiple models to achieve reliability and understanding• ¼ simple model, similar to ANSYS model by others, air treated as “solid”

under bridge• ½ model with air box to allow for 3D air effects (not just under bridge), no

air flow

Air gap

¼ model

Air box for 1/2

½ model

C. Haber 6-Mar-0823

FEA Models of Bridged Hybrid -II

Multi-hybrid model

• Multi-hybrid model, with air flow included(so far 0.01 m/sec)

• For simplicity, all studies so far done with tube wall temperature fixed at -28C, 0.25 W/IC and no detector heating.

• Goal is to compare first with glued hybrid under same conditions

• More details are here and here

C. Haber 6-Mar-0824

Short Summary• Good agreement among models

• Modest effect of gas flow

• Reduced K means lower than nominal K in structure. No optimization of structure yet

• For comparison, nominal design (hybrids glued on silicon) for comparable assumptions yields max sensor temperature of about -22.5C

Model IC Peak

Temp(C)

Bridge

Gradient(C)

Sensor

T Max(C)

¼ model -5.8 6.6 -20

½ model -6.3 6.8 -20.2

With air flow

-15C gas

-5.9 7.6 -18.7

¼ model

Reduced K

3.4 5 -16.7

C. Haber 6-Mar-0825

Conclusions

• Focused attempt to address the plans and issues discussed in Valencia

• All components for Stave-2007 are in-hand

• Approach is friendly to alternatives – bridges etc

• We welcome the participation, input, or suggestions of the community

• Look forward to preparing for the June review