Report from Module Bonding Working Group Meeting

1. Report fromModule BondingWorking Group Meeting Salvatore Costa Università di Catania and INFN – Sezione di Catania

2. Outline • Global info on production bonding of the Modules • Global review of Module bonding quality indicators • Selected highlights from Center reports • Decision on Module Grading initiative

3. Globalinfo on production bondingreview of Module bonding quality

4. Production Summary

5. Module Pull Tests Performed Results in DB from 13 Centers out of 14 # Modules pull tested after 01Dec2003 (at last Mtg)

6. Center Averages Not angle-corrected yet! 5g BA CT FI PD PI TO FL FL SB SB HA KA ST ST VI ZH . ss ss ss

7. Selected highlights from theBonding WG Meeting of 26 Oct 2004

8. TEC centers • In general production Bonding has slowed down or has now come to a stop • However, for some TEC centers this was their first chance of reporting on bonding of a significant number of Modules: • Aachen tuned machine parameters using some 5 faulty modules, after which was able to bond 10 with very good results [pull forces 9-10 g and mostly heel breaks, pull test data now in DB]. • Karlsruhe received 23 Ring-5 Modules from Brussels Gantry, bonded 17. At the moment they have problems bonding on the PA, resulting into as many as 20 re-bonds per Module. Perhaps they have to still tune parameters. Also complained that modules arrive with very dusty carrier plates and cleaning them is tricky as that tends to wash the dust on Sensors. • Vienna has now bonded ~115 modules and now is looking into buying a new machine (likely Hesse & Knipps). • Zurich has bonded 335 Ring-4 Modules with final 97% acceptance. Bonds are of excellent quality in general as testified by the pull test results. Some specific problems encountered are: • 19 modules delivered in July had the pitch adapter protruding over the sensor. • Out of those, 8 modules with variable distance PA – Sensor. • There were about 20 % floating modules. Preparing new jigs to avoid that the stiffener can touch the jig.

9. TIB centers • In general production Bonding has slowed down or has now come to a stop • Catania still has a few modules to bond. Had failure in electronics board of Hughes  fixed. • Firenze also had a serious failure of Delvotec which required service. • Padova reported some technical problems bonding the TIB Layer1/2 stereo modules because of conflict between some jig areas and a certain ceramic support piece of this type of modules. • Pisa said they noticed the same problem and solved by simply milling out a small piece of the jig. Having run out of modules to bond, the other task of monitoring bonding quality of Sensor batches by executing pull test in the half-moon Sensor Test Structures will be now resumed.

10. Decision on Module Grading initiative

11. Module Grading (GantryBonding) Hybrid position check at Gantry • The Gantry group continues to measure, and record in the usual DB tables, data concerning position of the hybrid, • But they no longer write into the DB a NEGATIVE flag (=FAULTY module) based on values of those data ANDship the modules to Bonding REGARDLESS of those data. • Gantry writes a flag anyway (but a POSITIVE one!) to the DB • New Bonding DB interface version (in the works) checks that variable and displays a warning (in the Pre-Bond Inspection Section) if appropriate

12. Module Grading from Bonding (1) Grading based on # unbonded strips • First flag in BONDSTATUS_VAL vector: • 0 if n_unbonded <1 • 1 if 1% - 2 • -1 if >2% • These are consistent to grades A,B,C of ModTest and the module is faulty with >2% unbonded strips.

13. Module Grading from Bonding (2) In addition to that, we have now adopted a second, independent, Grading scheme based on mechanical quality of the bonds • Idea emerged in June 2004 within TIB bonders community • Presented for first time at July 2004 Tracker week • Mixed reactions, different opinions… • The Bonding WG Technical Advisor supports it and has contributed to determining the criteria for this grading • I will now implement it with the next release of the Bonding DB I/F and start looking after its adoption by Centers

14. Module Grading from Bonding (3) Grading based on mechanical quality of the bonds • Technical implementation: • Add in the BONSTATUS_VAL vector a second flag • Possible second flag values would be again 0,1,-1 corresponding to grades A,B,C. • For example a module with BONDSTATUS_VAL=“:0:1:” would be of grade A for # of unbonded strips, but grade B for mechanical quality of the bonds

15. Module Grading from Bonding (4) Grading based on mechanical quality of the bonds • Criteria to generate this second flag: • # Bias Bonds (Spec: 5, 15 for TIB back) • >2: grade A (flag 0) • 2: grade B (flag 1) • <2: grade C (flag -1) • # “critical” readout bonds [definition list of “critical” by Alan]: • ≤ 2%: grade A (flag 0) • > 2%: grade B (flag 1) • > 20%: grade C (flag -1) • Operator judgment on all other bonds [guidelines to issue this judgment by Alan]: • A, B, C. • These criteria will be or’ed together to generate flag.

16. Module Grading from Bonding (5) Grading based on mechanical quality of the bonds • Method to generate this second flag: • Add to Bonding DB I/F section where operators may enter: • Number of bias bonds in each spot • Number of “critical” readout bonds as defined by Alan • Judgment on non-critical readout bonds as per Alan’s guidelines • Explanation of reason(s) why a module may be non-trustworthy • Of course all these new fields will default to “perfect • module” values • Normally operator will have nothing to type if Module was bonded • with no problems • I/F script will calculate final flag