Minutes of the Tracker Technical Meeting
May 29, 2002
(Note: the discussions with Sandro occurred on May 30)
1. Update on EM status:
- ladder assembly (dummy & live)
- closeout machining at Plyform
- insert bonding tooling
- insert installation
- tray panel assembly tooling
- tray panel assembly documentation/drawings
- tungsten assembly tooling
- kapton assembly tooling
- mini-MCM testing with ladder
- ASIC production (MOSIS predicts wafers completed August 12)
- dummy MCM assembly
- thermal gaskets
- lifting/handling fixture
- readout cables
2. Tray vibration testing plans
3. Son-of-shake test status
4. Planning a new schedule (Tom's trip to Italy, etc.)
Tom said that the VO-Soft gasket material will be used for the vibration test next week. It is the one material that Tom has that feels sufficiently elastic.
Tom did not have status on Teledyne but will call them about wire bonding results with aluminum wedge bonding. The 1 mm screws for connector mounting are on order. Screws are in hand for attaching to the holder. The molded plastic holders will arrive soon (they arrived the same afternoon). The cups to keep the screw holes open during encapsulation are to arrive Friday at SLAC. Teledyne is waiting on these items before manufacturing the dummy MCMs for the EM. Robert said that he will send the non-functional e-version front-end chips to SLAC to send to Teledyne for the dummy MCMs. They will be a somewhat better test of the wire bonding than the dummy chips.
Tom said that they will start stacking the tower today and plan to go to Ames on Monday.
There was some discussion of vacuum chambers for qualification testing. Dave Nelson borrowed equipment from the SLAC vacuum group to put together a small system. It is now at UCSC for testing of the poly-fuses. It is supposed to be returned in a couple of months, so any plans to use it for other tests will require negotiation with the vacuum group. Ossie is working on a vacuum chamber for SSD ladder testing, etc. Robert requested a plan and schedule for this.
Robert asked whether vacuum testing will be required for MCM qualification. He noted that we still need a written plan for this. Tom suggested looking at Nick’s flow diagram for the MCM from his PDR presentation. Hartmut offered to help get this going.
Luisella said that the insert bonding tooling is complete for mid-trays. She and Sandro will go to Plyform on Friday to make dimensional tests on it and on the tray assembly tool. (Last week’s minutes said that Ricardo would do this last Friday, but that did not occur.)
She said that the remaining carbon-carbon material and GMSI machined closeouts are (finally) in Pisa. The will take them to Plyform on Friday.
The closeout machining status is the same as last week: they will see the first 16 closeout pieces on Friday and check them. These include both MCM-wall and structural walls, with 8 of each.
Tom said that we need an estimate from Plyform’s machine shop on the time estimates for machining the flight material. The reason is that this needs to be matched in the schedule to the Alcomp delivery schedule of the material.
Luisella’s document on subcontract specifications to Plyform are under review by Sandro. She is working on tray assembly procedures. She is waiting for the mid-tray assembly drawing with dimensional tolerancing from BJ, as discussed last week. BJ said that it will be on the web today. Plyform also needs the final drawings of the cut face sheets. BJ will complete this drawing today and put it onto the web.
Luisella is working on the tungsten assembly tool for thick foils. She will afterwards work on the Kapton assembly tool. She will send the tungsten assembly tool drawing to BJ for adaptation to the thin tungsten. For this she needs 2 weeks.
Luisella will send to BJ insert bonding tool drawing for top/bottom trays, for him to complete.
There was some discussion of Sandro’s request to do vibration testing of individual trays only before mounting of detectors and electronics. This will help verify the workmanship on the trays before committing them to bonding of valuable detectors. It also works better logistically (compared with vibration testing completed trays), and it avoids removing trays from their protective boxes to mount them onto a vibration fixture. Everybody generally agreed with this plan. However it did raise the issue of how to verify the bond from tray-panel to SSD. Tom suggested adding to the procedures witness samples that use the same working batch of adhesive during each assembly session. Sandro agreed that this can be done with Kapton-covered coupon and an SSD cutoff. He emphasized that a vibration test would not effectively test this bond-joint anyway.
Erik went back to the tray-panel testing. He felt that the vibration test would not effectively verify the workmanship of the panels, particularly the bond of the facesheets to core. He asked whether Plyform would do any QA test after panel assembly, for example a coin tap. Luisella said that she will discuss this with Plyform on Friday. Sandro said that Ricardo is studying various possibilities. Robert noted that this must be include in procedures that Luisella is starting on. Luisella said that they have in mind 2 shake tests for EM panels: once before adding tungsten and Kapton and once after. Robert expressed concern that this may cause too much delay in the schedule.
Tom plans to go to Italy to discuss and finalize the new Tracker schedule with Sandro and Ronaldo. He will arrive on June 11. Sandro will arrange lodging for him June 11 and 12.
Tom will send his draft schedule to Luisella et al. in pdf format, including the 6-month increase.
Robert asked Luisella and Sandro to talk to Plyform on Friday to make a realistic estimate of when the tray-panel fabrication will occur. (Please take into account summer vacation issues.)
Pisa will glue a ladder onto the UCSC fixture tomorrow in Pisa and ship it on Friday or Monday. UCSC has a working mini-MCM ready to connect to the ladder for noise testing.
The ASIC run is in progress, with MOSIS showing an estimated time delivery of August 22 for unpacked ICs.
The readout-cable procurement is presently in the hands of SLAC purchasing.
Sandro needs information on future SSD delivery in order to plan the ladder assembly and G&A/MIPOT. Tom said that he will get this from Ohsugi (maybe Hartmut can help with this).