Minutes and Actions of Site Qualification Task Force

Transcription

1 Minutes and Actions of Site Qualification Task Force Phone Conference - 7 th of April 2004 Present: G. Darbo, M. Garcia-Sciveres, P. Gerlach, D. Giugni. F. Huegging, L. Rossi, E. Vigeolas. Status and Updates from Loading Sites. Genova. Flex trimming tool has been upgraded by the use of German blades. The trimming has been improved and the test on last 5 flexes gives values of µm, to compare with µm obtained by old blades. The vacuum holder of the robot has been modified by adding aspiration on the 2 middle metal legs. This reduces the bow of the loaded module to 20 µm (measure made by a graduated microscope reticle). Other 5 modules (10 in total) loaded on the FE-I2 stave. Stave cold box completed. Next week are planned qualification test of the loaded stave. Lack of R/O electronics: PP0, TPLL/TPCC, ST regulator board, will require sharing with other setups and partial stave powering and R/O. CPPM. No new modules added on stave. The flex trimming tool has been upgraded, but not tested on modules yet. It is under study a shipping box for stave. Measures of module displacement as function of pull force on pigtail have been made. Lateral (y) module displacement is elastic up to 500 g and of 0.1 µm/g. Results are reported in the document: Module position stability measurements. Wuppertal. The new clean room is ready and the loading robot is in reassembly phase. Next week also the stave test setup will be moved in and put to function. The FE-I1 stave will be moved to Bonn to repair damaged wire bonds on two FE chips (modules were not potted). LBL. The 3 rd sector is in phase of loading with 3 FE-I2 modules. A new scheme of sector cooling has been made using two cooling circuits and a heat exchanger. The sector is cooled with C 6 F 14. No test of efficiency of the system and temperature drop made yet. Glue deposition procedure. Eric has prepared the document SE4445 mixing and deposition which describes the procedure to prepare and use the glue for attaching the modules to stave/sector. The main issues of the procedure and the difference from site to site are: Mixing 1:1 (±3%) ratio by weight of the grey/white compounds. Genova uses the same mixing ratio. LBL used 36/40 by weight chosen by a test of least tackiness after curing. They now standardize on 1/1. To apply the glue the procedure specifies syringes (ref LL-B), needles (ref /0.35 mm length/internal diameter) and pistons (ref PE-B) from EFD ( LBL is now using the same, Genova will order them. Pressure and flux. Pressure must be regulated to obtain 18 drops/minute. CPPM obtains it with 1 bar pressure, Genova with 1.8 bar. The difference is mainly due to the use of different kind of piston (CPPM needs bar to move the piston in empty syringe, while Genova needs 1.0 bar).

2 Quality control of the glue is made by applying 5 drops on a glass slide. The procedure specifies that the size of squeezed spot between two slides is 10 mm. After discussion we propose to leave the spot un-squeezed (diameter = 3.5 mm). Shear test is made on a sample for each glue preparation. Stave and sector cooling, cleaning and thermal qualification. Long discussion on how to cool the stave and sector for qualification test. The use of perfluorohexane (C 6 F 14 ) cannot be made in unsealed circuit because it is extremely volatile. LBL has made a sealed system and will perform test on it to see if it is good enough for qualification test. In case of stave the requirements are bigger due to the number of modules. The perfluorohexane doesn t need particular cleaning procedure of the aluminum pipe. It has been decided to investigate the use of aqueous glycol liquid or other coolants. The liquid to be used must not cause corrosion of the pipe. It is also necessary to find a cleaning procedure for the pipe afterwards. Danilo has been asked to investigate for solution with experts at CERN. Other groups in contact with chemical departments have to propose a solution. Because all the bare staves have been tested by cooling them with glycol (probably) a cleaning procedure is needed anyway. The cooling setup needed to qualify the modules must be capable of: Reach 30ºC without powering modules. Reach 10ºC with at least a module powered. Reach (0 10ºC) with all modules powered. Thermal qualification seems quite difficult with the use of IR camera. In particular seems difficult to find missing glue under FE chips or effect of bowing on module temperature. More tests will be done on stave and sectors in all sites to verify the sensibility of the method. Procedure log sheet and qualification results template. Giovanni presented a proposal of procedure log sheet (what in the module world is called traveler) to be used to annotate the operations of module loading on stave. A draft of the presented log sheet is in the appendix. This log sheet includes the flex trimming, the glue deposition and the module placement (in the site qualification master document ATL- IP-QA-0023 there were proposed separate log sheets). The TF members had a general agreement, but they will look at it in detail and make comments. The log sheet will be used for the preproduction. For qualification test we want to use a template where the tests will be made and the results will be presented in a coherent way amongst the different sites. For the electrical qualification Fabian will make a proposal at the next System Test TF phone conference (22/04) and we will have a first discussion there. Genova and CPPM will propose a template for geometrical qualification of staves and LBL of sectors. Those templates must exist in the draft form and filled with results from FE-I1/I2 assemblies before starting preproduction (end of April) and in their final version to qualify preproduction (June PW). Next phone conference. Next phone conference will be held on the 29 th of April. The goal of that phone conference will be prequalification of sites. For being able of qualifying a site the SQTF must receive a report with qualification results of the FE-I1/I2 assemblies. Those results should be prepared in conformity to the qualification templates.

3 Action list Tasks to be completed before loading FE-I3 modules, i.e. preproduction 1) Finalize flex trimming setups (for stave). Routine test that <300µm cut is safely made. Action on All stave sites. Status: done 2) Implement weighing procedure on modules to be loaded. 10 mg precision. Put on procedure log sheet. Action on All. Status: already implemented in Genova and LBL. 3) A detailed description with quantities and times of the procedure to prepare and use the glue. Action on Eric. Status: prepared, some modifications requested. 4) Measure location of deposited modules as a function of pigtail / type 0 cable bending / plugging-unplugging. Action on Eric. Status: done 5) Perform bow measurements on FE-I2.1 loaded modules and compare with flex module bow. Determine cut for maximum acceptable flex module bow for loading. Action on All. Status: to be done by all sites. 6) Implement and test cleaning procedure for cooling pipes after having used C6F14 liquid coolant. Action on Maurice. Status: done for C6F ) Cleaning procedure for bare staves and for a possible different coolant liquid to be used in place of C 6 F 14. Action on Danilo. Status: new action. 7) Measure deposition yield of production quality FE-I2.1 modules (modules with travelers are production quality). Must define an initial set of cuts for deposition yield, based on initial experience (delta-bumps, delta leakage, delta x,y,z, delta-t, etc.). Check that real fittings are not damaged/degraded by connections to liquid coolant system. Action on All. Status: to be done. 8) Test with IR of missing glue under a FE chip. To check the sensitivity of the thermal imaging method a FE chip at the time will be put in condition of low power and IR image will be taken. To reduce the heating hot spot of the MCC the clock can be switched off. In this case the MCC power is reduced by 60%, but also the digital power in the FE chip is reduced significantly. Action on Genova/Wuppertal/LBL. Status: to be done.

4 9) Prepare (update) module deposition log sheet (traveler) with the main operations for review by collaboration. Action on SQTF. Status: draft made, waiting for comments. Task to be completed before full qualification of preproduction: 10) Prepare electronic logbook or qualification template format to be used for qualification test. Status: electrical test from Fabian, geometrical qualification for stave Giovanni and Eric, geometrical qualification for sector Maurice. Status: to be done 11) Prepare & test storage box for loaded stave/sector. Action on All. Status: to be done. Eric has some prototype on the way. 12) Survey and raw DB. Action on All. Status: to be done 13) Commission test setup allowing 1-module-at-a time testing on stave or sector with C6F14 cooling. Action on All. Status: to be done

5 Appendix ATLAS Pixel Module Loading on Stave Procedure Logsheet Stave S/N: Site (circle): GE / CPPM / WU Responsible: Start Date (dd/mm/yy): End Date (dd/mm/yy): Module # xx Receiving test Date: Operator: Flex cut Date: Operator: Distance cut/sensor (µm) FE#0/F side: FE#7/8 side: Weight (g): Glue deposition / module place Date: Operator: Glue opening date: Time mix/deposition: Weight grey/white (g): Drops/minute: Pressure: Needle: S/N Shear test Quality of glue deposition (comment) Distance needle to stave (µm) Distance / force plot (comment) Bow (µm) Gap sensor/step (µm) Quick test Date: Operator: Yield evaluation Status pass/accept/reject: Reworking (pass/accept/reject): Comment: