- Tower A is arriving at SFO this afternoon.
- Plans are in place to unpack it and install it into the cleanroom Saturday.
- Electrical testing and cosmic ray data taking will occupy Sunday and Monday.
- The CMM at SLAC will be used to recheck the alignment next week.
- Then the tower top will get taped with aluminum for EMI shielding, and the EMI/EMC tests will be done.
- The tower is assembled, tested, packed, and on its way to Alenia for environmental testing.
- Vibration testing will commence on Monday. The TRR was held this morning.
- The Tower-1 sidewalls have been laid up and are ready for machining.
- All parts for Tower-1 tray assembly are at G&A and were inspected this week.
- SSD wafers were selected for heavy tray ladders to be assembled without encapsulation. Such ladders will be used on all heavy trays and bottom trays from Tower 1 onward to avoid the issues with encapsulation delamination and wire bond breaking on the ladders.
- A lot of work was done this week to understand the issue with pitch-adapter trace cracking.
- The board radii were measured in detail and ruled out as being the issue.
- A fixture was built to study bending of pitch adapters over a 1-mm radius with controlled tension. We found that with less than 5 lbs tension there is no cracking at all when the pitch adapter is bent around the radius. 9 lbs is required to cause traces to crack open and become non-conductive.
- The Teledyne fixture design was studied and understood to apply an uncontrolled and potentially high tension to the pitch adapter.
- Richard Gobin is at Teledyne today working with them to try to adjust the fixture such that it works at least as well as it used to.
- An engineer is working to turn the G&A pitch-adapter bonding fixture into something that could be used in production, with the hope of restarting production next week.
- Parts were prepared to make a test of pitch-adapter bonding using the G&A prototype tool with pitch-adapters from the existing stock.
- Getting MCM production back on track is schedule critical, as the existing stock of MCMs can only equip about 5.5 flight towers.
- The low yield to date requires us to order more MCM parts, including more front-end ASIC wafers. Those requisitions are in progress.
- 8 “cables” made especially (and economically) for stacked
tray testing are almost ready to ship from SLAC to
- 8 more reject Parlex cables (which work fine, anyway) will also be sent for stacked tray testing.
- The Parlex process has been shown to be greatly improved by inclusion of the water-blast cleaning of the drill holes.
- SLAC conducted another thermal cycle test on 4 Parlex cables with *bad* coupons. All survived with complete functionality 100 cycles that exceed the Tracker qual range.
- Parlex production will give us 2 to 4 of each cable type by the end of this month. In addition, more than 4 of each type are in process.