Minutes of the Tracker Meeting
January 29, 2004
There was a brief report by Tom on the meetings this week at Plyform.† In general the outcome is positive and Plyform is in good shape for tray production, but we need a report from Darren.† Ben Rodini was there also and found that we need specifications for materials for sidewalls; he will do this work.† Jim will notify Toan at COI that Ben will work with him.
Tom noted that we need a better understanding of the goals of the bakeout procedure.† What is the issue or requirement?† Bubble detection in Kapton?† Contamination?† How is efficacy evaluated?† Tom Venator has this action for the moment.
Jeff reported that the honeycomb has been inspected by LAT QA and will ship very soon to Pisa.
There was a discussion of bias circuit issues. †Sandro is not happy that Parlex added bus lines for plating that now have to be trimmed through when the bias circuit is trimmed during tray fabrication.† He did not want to have to cut through the metal or have the trace come all the way to the edge of the circuit.† Unfortunately, nearly all of the $90,000 order has been fabricated by now, so this has to be looked at carefully.† In any case, Tower A fabrication will proceed with the present circuits.
We learned that the thermal-vacuum meetings got done more than anticipated.† We are back to a March 1 start.† Nicola is posting minutes on the Bari web page (see also the SLAC Tracker web page).†
MCMs: 7 MCMs are shipping out to Pisa tomorrow after reviewing data from CMM.† 5 MCMs shipped to SLAC from Teledyne yesterday and another batch is expected Monday.
Robert reported that the GTRC-7 wafers test good and one will be diced by Tuesday.† We want to get GTRC-7s into the tall preproduction MCMs.
The MCM PRR is scheduled for February 10, at Teledyne.† Luca Latronico will attend the meeting to represent INFN.
Martin reported on issues with the Flex Circuit Cables.† Solid models and draft files are not linked or constrained correctly.† He has 2 designers working on it.† One is remodeling cables to get the relation between bent and flat cables.† Another is checking dimensions against the tower.† The IDD is now the governing document.
Robert reported that the flex circuit cables need another resistor added to each cactus arm to limit current flow into the address lines in case an MCM shorts out.
Martin working on checking Ti designs.† BJ is making the drawing mods.† Martin thinks he sees an error in the structural closeout wall drawing/model.† A thickness is incorrect in the tray model.† COI has not started machining and is on hold.† We will need to rev the drawing for sure.† Martins general plan is to work the design with hand calcs, update the drawings, order Ti at risk, then update models.† On the corner-bracket/closeout joint Martinís tolerance stackup indicates a 2 mil to 20 mil bond line variation worst case (not RSS).† Rodini said that a 5 mils bond line is the minimum needed.† Martin predicted end of next week for Titanium and closeout drawings.
Martin & Mike are planning to travel to Italy to review tooling drawing and assembly procedure.† Before then Martin will send details on the piece parts and tolerancing.† They are planning for the end of the week of Feb 9 in Pisa.† Riccardo will try to finish the tooling drawings by end of next week.†
Jack said that he needs to know the resistor values on the EM tower dummy MCM boards.† Robert will send that information.
Jeff will try to find the Plyform sidewall thermal coupons and get them measured.† Erik will send info on the test lab to Jeff.† Jack will be responsible for specifying the measurements.
Static test fixture: ship from Hytec Monday Feb 9th.† Jeff will coordinate shipping.† First Erik wants to take photos for the procedure document.