C. Haber 6-Mar-08 Integrated Stave Electrical/Mechanics/Cooling Update March 6, 2008

C. Haber 6-Mar x 3 cm, 6 chips wide 10 x 10 cm, 10 chips wide 1 meter, 3 cm strip, 30 segments/side 192 Watts (ABCD chip), ~2.4 % Xo + support structure 1 meter, 2.5 cm strip, 40 segments/side Watts W/chip) ~1.9 – 2.2 % Xo + support Stave-07 Stave cm, 9 cm strip, 6 segments/side Stave-08 Prototypes and Designs Build and test Study

C. Haber 6-Mar-08 3 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-08 4 Aspects Status overview Components Fixtures Electrical testing Additional critical tests Alternatives

C. Haber 6-Mar-08 5 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-08 6 Status Overview Central goal is assembly and test of Stave 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-08 7 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 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. Ground layer Power layer Analog power Digital power Analog current LVDS section Serial power section

C. Haber 6-Mar-08 9 Hybrid HV-GND options HV in HV Gnd AV-MOD AG-MOD AC gnd

C. Haber 6-Mar Fixtures for Assembly AND Test

C. Haber 6-Mar Module Assembly and Test Fixture  volve a  single fixture for assembly, bonding, inspection, and test.

C. Haber 6-Mar Bus Cable Signal Layout Serial current link Serial current return HV distribution Clock & Command lines Data Readout 1/hybrid Port Card

C. Haber 6-Mar Bus Cable: Shielding  l foil, 50 um thick, can be grounded to each hybrid

C. Haber 6-Mar DAQ

C. Haber 6-Mar HV Supply for 30 step serial system GENH 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 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 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 2fc ref Glued on

C. Haber 6-Mar continued Ref Glued on

C. Haber 6-Mar 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 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 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 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 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 herehere

C. Haber 6-Mar 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 ModelIC Peak Temp(C) Bridge Gradient(C) Sensor T Max(C) ¼ model ½ model With air flow -15C gas ¼ model Reduced K

C. Haber 6-Mar 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