July 23, 2004
Tower-A Tray Panels
- Production is getting back on track following the problems with
Kapton adhesion to the tungsten. The tungsten foils have been
bead blasted with a 1-micron roughness, and plans are being
finalized to prepare the Kapton surface also.
- Plyform has committed to a schedule for the Tower-A trays and
will work Saturdays through August 6 to complete the work by
that date on all Tower-A trays plus some spares.
- The TRR for the Tower-A bottom tray static test was completed this week.
- 222 MCMs have been produced, and 194 have been received by SLAC
- 109 of them have been reworked with 75-ohm resistors for the clock
bus terminations. The rework is proceding rapidly, and finally
SLAC purchasing authorized a PO change for Teledyne to start putting
the 75-ohm resistors on in production.
- Only 2 flight trays will have MCMs with 100-ohm termination, as a
stock of reworked MCMs is now in Italy.
- Some of the revised pitch adapters finally arrived, and now there will
be a push to qualify them in the process and get more ordered.
Tray Assembly (MCM and ladder integration)
- 2 flight trays have trailblazed the entire process through MCM mounting,
ladder mounting, wire bonding, and encapsulation with excellent results
- G&A did a beautiful job of developing the MCM attachment, wire bonding,
and encapsulation processesover the past few months, and on these trays
the number of bad channels (out of >6000), measured before encapsulation,
could be counted on one hand and was far below the maximum allowed. Only
2 channels were missing the wire-bond connection. The cause was found to
be contamination on the pitch adapter circuit. Those bonds were reworked
and a new, more aggressive cleaning of the pitch adapter will be done
in the future.
- Early next week the encapsulated trays will be functionally tested and
then put through thermal vacuum cycles as final qualification of the
- G&A has agreed to defer vacations until the Tower A trays all are
assembled. We expect that the last tray will be done and ready for
testing around August 8.
- Plyform will have the Tower-A sidewalls completed before the August
- SLAC is preparing the PO for the remaining prepreg needed for the
- Coupons from the first cables were sent to NASA for testing.
- Parlex agreed upon a new delivery schedule for the remaining flight
cables which supports the Tracker schedule.
- The first sets of heat straps are in Italy ready for their incoming
inspection. The tie-down bars need to be modified by cutting them
from 1 piece to 2, to facilitate installation (the drawings have
been so modified).
- The Tower-A hardware will be shipped to Italy next week. There was
a delay with the hex bushing, which was originally made from the
wrong material and had to be redone. The delay had no impact on
Tower A, however.
Cable Corner Brackets
- The design was signed off this week, and procurement has begun. These
are the last pieces of Tracker flight hardware to be designed.
- The M2.5 100-degree head screws were inspected and are good to go.
- The 2mm pins are also inspected and ready.
- The detailed procedure documents and assembly drawings are still in work.
- The CMM-based alignment procedure was successfully developed and tested.
The cones can be readily adjusted to better than the needed precision.
- Assembly of Tower-A is scheduled for the last week of August.
- INFN located a TQCM to be used at least for Tower A testing.
- The environmental tests for Tower A should be done in the time frame of
September 6 through September 17.
- The cable holding plate was completed.
- The lifting fixture was proof loaded and is ready to ship.
- The inner shipping container was assembled and will be proof loaded
- The cactus-arm cable bending tool is in the shop.
- The tooling-ball nests are in the shop.
- 18 vibe fixtures are still in fabrication.
- The outer shipping container has been spec'ed out and a print is
in preparation for review. An environmental recorder with battery
and memory sufficient for the entire trip to SLAC was found and is