Minutes of the Tracker
Meeting
January 29, 2004
Action Items:
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 Martin’s 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.