1. Slide 1PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder CMS Module Testing Issues Perspective from a large scale production project Anthony Affolder (for the UCSB module testing group)

2. Slide 2PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Talk Overview Review current CMS testing procedures Assorted observations from limited testing experience on CMS components Outline UCSB module testing program à Personnel, equipment, and infrastructure

3. Slide 3PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder CMS Testing Overview Review current CMS testing procedures à Ensure understanding of testing prior to arrival at FNAL/UCSB –Reproduction of hybrid tests on arrival à Make sure any systematic failures in production techniques/materials found as early as possible –M800 pre-production first chance to produce large quantities (>20) of single type of modules –Need to be able to track time development of faults Answer open questions before full scale production à Need of burn-in of hybrid/optical systems components à Finalization of production procedure à Finalization of testing procedure –Both fault finding and module qualification

4. Slide 4PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Tests Prior to Arrival at FNAL/UCSB APV Chip Testing (1 minute) à Voltage stressing (6 sec) à Basic Functionality –Pedestal –Calibration Injection (2 MIP) –Pipeline FHIT-Industrial Testing (1 minute) à Connectivity à Basic Functionality –Pedestal –Calibration Injection (2 MIP) –Noise Strasbourg à ????? CERN-Pitch adaptor bonding (20 minutes) à Basic functionality –Pedestal –Noise –Calibration Injection (2 MIP) à Capacitive pulsing pitch adaptor à Thermal cycle to –20 C –Repeat test à Warm to room temperature –Repeat test

5. Slide 5PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Testing Concerns Hybrids tested only ~1-20 minutes à Concern about infant mortality problems Hybrids not completely characterized à Calibration circuit only tested at one injection point à Pipeline pedestal/noise not thoroughly measured Requirements not consistent between sites à Pedestal cuts changes between test stands à On-chip common mode subtraction “feature” makes noise characteristics of open/saturated channels unpredictable We are attending CMS tracking week to address issues à Motivate requirements on fault finding/performance issues à Continuation of bringing CDF/D0 production experience to CMS

6. Slide 6PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Test System Grounding Issues PC, DAQ/ARC, LV supplies, and HV supply share common ground à Leads to less than predictable results Suggest that a common-mode noise standard made à With on-chip common mode subtraction removed (inverter off) à Allows for more uniform testing results

7. Slide 7PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Lower Noise Requirements Sensor-Sensor Open Visible Improving grounding until common mode noise less than ~0.5 ADC in peak mode/ inverter off allows the use of raw noise as a powerful tool for finding opens, including the location Sensor-Sensor Pitch Adaptor-Sensor APV-Pitch Adaptor (???) Seen by Charge Injection TOB Module 83

8. Slide 8PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Upper Noise Requirements High noise only affects signal efficiency (clustering) Use physics (radioactive sources/collision data) to determine cut value à Expect values to be different for different systems SVX

9. Slide 9PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Gain Measurement Multi-point gain measurements have many advantages à More stable à More uniformity between chips –Tighter Cuts à Shows non-linearities à Shows non-uniformities within chip Gain Scan (0.5-3.0 MIP) (2 MIP injected)/2 TOB Module 83 TOB Hybrid

10. Slide 10PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Noise Chip Edge Wings Increase in noise at chip edges à But only in a few pipeline cells à pipeline scan=latency scan Deadtimeless effect!! à Fairly easy to reduce/avoid

11. Slide 11PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder UCSB Short-term Testing Plan Characterize hybrid (+PA) on arrival à Basic functionality, gain scan, and deep test (ARC) Re-characterize module on completion of construction à Basic functionality, gain scan, deep test, and IV curves (ARC) Vienna cold box test fraction of modules (DAQ) à Acts as ~24 hour module burn-in –Identifies mechanical/bond/electrical weaknesses prior to production of large number of modules –Reduces reworking of rod/retrofitting of modules Rod assembly/characterization/burn-in (when parts and test setups available)

12. Slide 12PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Testing personnel at UCSB Professors à Joe Incandela à Claudio Campagnari à David Stuart Post-docs à Anthony Affolder à Patrick Gartung (UC-Riverside) Graduate Students à Steve Levy à Shawn Stromburg à +1-2 starting this summer Electrical Engineering Support à Sam Burke ESE Master Student à Anuroop Gupta (Database/programming) + Assorted Undergraduates and Techs (during full production)

13. Slide 13PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Current UCSB Testing Setup Clamshell(UCSB) à Plastic stand-offs –2 Locating Pins à Kapton Extension Cables(UCSB) –Easy connection/disconnection à Solid mounting of DAQ equipment 1 ARC Controller + 1 ARC FE LV & HV Power Supplies Dry Air Clamshell

14. Slide 14PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Testing Facilities High Bay (Ground floor) à Rod assembly/burn-in à Convenient access to loading dock Clean Room (5 th floor Physics) à Adjacent to production area à Module tests –Fault finding and deep tests à Module burn-in station à Visual inspection table

15. Slide 15PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Safety Protocols LV à OVP,OCP HV à Crowbar Protection Electrostatic Protection à Ground mats on tables and floors à Heel straps à Combo tester at clean room entrance à Touch tester at each station (Artist Rendition)

16. Slide 16PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Testing Conclusions Slight modification of testing program would lead to more uniform and consistent fault finding between different sites/systems à Reduce rework performed on completed rods Location of opens can be identified by combination of noise and internal calibration measurements à Useful for rod burn-in fault finding Increase in noise at chip edges likely deadtimeless effect à We are willing to study more thoroughly We have the manpower and the experience necessary to aid in development of the testing program while performing module quality assurance measurements

17. Slide 17PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Backup Slides EVERYTHING AFTER THIS IS BACKUP SLIDES

18. Slide 18PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Possible Rod Burn-in Issues LED systems may be necessary for discovery of “high current” pinholes and location of opens à In current rod burn-in plan, no LED systems available à Would necessitate new techniques to locate “high current” pinholes and opens –New sensor qualification tests, backplane pulsing, lower common mode noise, etc. Burn-in at module stage provides important information on this issue à LED tests still available à Until rod components arrive this is not an issue

19. Slide 19PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Example of DAQ/ARC Differences

20. Slide 20PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder On-chip common mode subtraction Inverters share common point à Current flows between channels Regular channel noise:   2  raw 2 -  cm 2 Opens/saturated channel noise:   2  raw 2 +  cm 2 Depending on  cm, open channel have higher/lower noise

21. Slide 21PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Deadtimeless Scan (ISL) Issue two triggers with varying time separation à Pattern of commands should include complete set of commands, measurements, resets, etc. à Measure pedestal and noise at each unit of trigger separation With ISL, every command, chip change of state, and data readout caused pedestal shifts à Would guess similar effect causing wing –May also be related to PC controller Removed with DPS at CDF (Time Between Triggers)

22. Slide 22PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Calibration Injection Test Enhance pulse shape information with gain measurement à Measure pulse heights at 6-13 calibration injection setting between 0-3 MIPs using internal calibration and fit à Require gain between G low and G high –Gain uniformity specification???  Require  2 <  2 cut (  2 based on noise measurement and knowledge of calibration circuit) –Finds non-linear charge response and gain non-uniformities within chip Relatively simple to include in ARC software Only moderately increases testing time Calibration is fairly sensitive to environment/grounding

23. Slide 23PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Test System Grounding Issues (1) Module Testing Final PS System PC LV -5V ARC Controller HV +HV Sensor Hybrid ARC FE 2.5V 1.25V GROUND LOOPS!!! LV HV +HV Sensor Hybrid HVGND GND +1.25V +2.5V DOH AOH Command And Data Cable Optical Cables Patch Panel/ Interconnect Bus

24. Slide 24PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder CDF Module Burn-in Experience Significant number of pinholes created during burn-in (even after 5 hours running) à L1- 0.166% of strips à L3- 0.052% of strips à L4- 0.033% of strips à ISL-0.0071% of strips 7 additional pinholes created during data-taken à L7 burnt-in at depletion voltage –All others burnt-in with over-voltage Early module burn-in in CMS will indicate pinhole creation rate and effect on rod rework rate

25. Slide 25PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Noise Measurements Lower noise requirements optimized to detect faults in production à Very loose low noise requirement at hybrid level –Noise only changes from ~0.6  ~0.4 for completely dead pre-amplifier –20% requirement will fail good channels Hybrid at UCSB tests better with shaper current set to zero à Tighter low noise requirements at module/rod level –Can identify open types/location Sensor-Sensor:~1.2 ADC PA-Sensor: ~0.7 ADC Chip-PA:~0.5 ADC Upper Noise requirement set by effect on signal efficiency à Noise sets channel’s thresholds in clustering à Effect is module type dependent –Larger signal and wide pitch minimizes effect on noise on TOB à Determine by source/cosmic testing

26. Slide 26PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Pedestal Tests (Current) Wafer Probing à Average Pedestal: 67.1 –50 <P < 90 ADC Cut FHIT (Industrial Tester) à Average Pedestal:~90 –±20% Cut:~72<P<108 ARC à Average Pedestal:~110 –±20% Cut:~88<P<132 DAQ à Average Pedestal:~170 –±20% Cut:~146<P<194 Pedestal Requirement vary by as much as 70% Try to develop common test based on detector performance Different requirements for different sub-detectors

27. Slide 27PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Hybrid Gain Measurement(1) Hybrid Tests on steel plate  Large pickup effects cause large  2 when 0 MIP point included   2 fairly good when excluding zero –Noise of calibration circuit not yet included 0-3 MIPs0.5-3 MIPs

28. Slide 28PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Bias Ring Voltage Voltage conversion assumes old resistor values in bias return circuit (22K ,100  With new resistor values (2.2K , 681  need ~120  A for regular pinholes need >300 mA for “high current” pinholes New Leakage Current (  A) Necessary With New Resistor Values LED Pinhole Tests  May cause damage to sensors!!! (Torsten Franke)

29. Slide 29PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Gain Measurements (2) Zero point offset Low gain High gain

30. Slide 30PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder R(22 kO) LED pinhole test characteristics will change with bias return line modification  Resistance on hybrid (22k ,100  )  (2.2k ,683  ) LED Pinhole Test

31. Slide 31PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Test model(1) Add hybrid qualification prior to pitch adaptor bonding à Thorough understanding of hybrids by adding more pipeline and gain measurements Make requirements/calculation algorithms consistent through testing process à Wafer Probing  FHIT  Strasburg  Pitch Adaptor Bonding  Module Construction  Rod Construction/burn-in –Allows for the reproduction of bad channel lists –Eases tracking of fault creation Motivate requirements for fault finding and on silicon tracker performance à Noise Occupancy à Signal Efficiency à Signal Resolution

32. Slide 32PMG Jan. 24 2002CMS Module Testing Issues-Anthony Affolder Test model(2) Improve system’s noise in order to use as powerful tool à Identification of location of opens Modify deep tests à Suggest different bad channel cuts specific to component type tested à Remove all percentage requirements (relative to average) à Replace with fixed requirements Use cooling box as module burn-in until shown unnecessary à Reduces reworking during rod assembly à Adds important information about necessity of LED tests for the finding of some pinholes and opens locations à Demonstrates if hybrid burn-in necessary