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LHCb VELO Hybrid. T. Bowcock University of Liverpool. LHCb Vertex Locator. Silicon Module. Components Sensors Substrate Hybrid Cooling Paddle Base Cables Module-0 ‘04. Silicon Modules. 50 modules Approximately 500,000 bonds Operation at –5C Thermal issues over assembly at 21C - PowerPoint PPT Presentation

Text of LHCb VELO Hybrid

  • LHCb VELO HybridT. Bowcock University of Liverpool

  • LHCb Vertex Locator

  • Silicon ModuleComponentsSensorsSubstrateHybridCoolingPaddleBaseCablesModule-0 04

  • Silicon Modules50 modulesApproximately 500,000 bondsOperation at 5CThermal issues over assembly at 21CVacuumMovement several times a dayBut very small magnetic field

  • Silicon ModuleDouble Sided ModuleModification from TDRTwo hybrids on one substrateSymmetry MassDifficult to fabricate and bond

  • SubstrateCF encapsulated TPGThermal conductivityMassBig relative CTE to kapton

  • Module AssemblyAll gluedCombination of film and robot dispensed glueTest of procedures for vacuum operationRemoving air VERY importantHow do we stop glue oozing out through holes (kapton), edges?

  • Prototype2002 prototypeBonded with SCT-VELO chipsSingle Sided(!)K&S 8090 pattern recognitionSensors150-300micronsKapton and Fanouts at CERNGlass Fanouts

  • PrototypeProblemsBad designLineup of Fanouts and sensorAngles of padsTwo types of sensor2 or more sets of fanoutsSensor pads cannot be made the same

  • 2003 PrototypeBeetle 1.2/1.3SubstrateLaminationBounceJigFlatnessDouble SidedKapton fanouts

  • Beetle 1.2 5100 6100m chip is very small Row to row centres are 150 um. Pitchwithin a row is 160um so the effective pitch for the four row bonding is 40um

    4 row bondingPads 120 95mSMALL

  • Pads at angle to Fanout?

    Sensor Pads under design and review

    Straight Line?Circle?

  • Proposed FanoutsThe fanouts have two metal layerspitch at the beetle end is the tightest with 40um tracks and gaps on each layer.the bottom layer protrudes out from under the top layer by about 400um. For four row bonding the two rows of beetle pads nearest the edge of the chip bond to the lower copper layer and the two other rows bond to the top copper layerThe copper is coated with nickel and flash gold.

  • Liverpool Semiconductor CentreK&S 8090H&K 710(2)Wirepull DageClass 100100m2

  • BondingLengths up to 3mmFanout to Sensor: TO BE IMPROVED17micron Al wireHeight Difference ~ 0.5mmSmallest Pitch dominated by BeetleMulti-loop height Wire pull tests Strengths >6g

  • Problems ExpectedFabrication of solid substrate/kapton that does not delaminateFlatness (helps bonding)Quality of bondingJig for Double Sided BondingNon-trivialPattern Recognition and Programming of 8090. Bonding on arc.Problem solved. Memory + ShippingOptimisation of Pad Layout Avoid foot being skewed relative to pads

  • ProblemsWe cannot afford to test at the same level as ATLAS/CMScycling, radiation damage etcProcedures have to be right20 modules = 50% of the production!Need to learn from ATLAS,CMS,+

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