Minutes of the Tracker Technical Meeting
October 30, 2002
1. Ossie: check on the shipment of COM card and interface board to Pisa.
2. Tom: purchase more 3M transfer adhesive for MCM attachment and ship to Pisa.
3. Tom & BJ: send the updated parts lists and drawings for the functional MCMs to Teledyne.
4. BJ: get the CMM work started on the top-tray assembly tooling.
5. Erik: check on availability of the BF Goodrich vibration facility.
Ossie reported that as of Friday, the status of the Invar measurements was that the measurements were completed and are awaiting review and write up. From what he saw on Friday, it looked like the Invar produces a 13% distortion in the measured magnetic field at a distance comparable to the location of the magnetometer on the spacecraft. This is the distortion as seen by the averaged total field. The distortion in particular components of the field is much larger, but with this type of measurement the most believeable numbers come from the average total field. This is with zero impressed field detected in the Invar. This will only be larger if there is any residual magnetic field caused by manufacturing or handling of the closeouts.
Sandro reported that Plyform assembled only one more tray since last week. They modified the heavy-tray tooling to have two setups for standard trays. He said that next week they will use this tooling to produce 4 standard trays. The tungsten assembly system us ready to be used next week. The Kapton assembly tool still is not yet measured. They plan to start gluing tungsten and Kapton on Nov 11. Nov 25 they will start placing ladders on trays. This will be done at G&A. They will have at that time 6 of the boxes designed at Bari for tray shipping and handling. These will be used to check performance in the thermal chambers.
Top tray machining has not yet started, but Plyform has all the materials and drawings.
Ladder production: G&A started putting together the setup to wire bond mockups. They also started today testing the new encapsulation materials. Next week they will begin ladder production without encapsulation. From 11 Nov. INFN personnel will be at G&A to test ladders without encapsulation. Encapsulated ladders are expected by the end of November.
Mini-MCM: Pisa is working on making bonds from the chips to the pitch adapter. They are working on finding a way to bring in the bias. The problem is that the MCM and ladder are not aligned properly, so that the bias connection of the ladder lines up with the center of a GTFE chip. They also have the software and can run it, but they still need the COM card and interface board. These were shipped 1.5 weeks ago. Tom will have Ossie look into it.
Sandro said that the ladders he is trying to ship to SLAC still are stuck in customs waiting for prolongation of temporary importation papers. He predicted that they would get going next week.
Sandro reported that the Terni clean room is ready for starting SSD testing. Sandro will make a final inspection next week of the clean room and procedures. Then they will start with 300 wafers.
Sandro said that they now have 14 tray panels assembled, including the one with intentional defects. He said that even the one with defects could be used as the top or bottom tray of the mini tower. He projects Nov 15 for completion of all of them. He plans shake testing of these trays before placing ladders. Robert asked how long the ladder placement will take. Sandro said that there is only 1 tool at G&A. Tom said that at SLAC they only waited about 1 hour for cure between ladders. Sandro estimated that they can therefore do about 2 trays per day. They will do 4 tray tops one day and 4 bottoms the next, to avoid flipping over trays with adhesive that has not fully cured. Robert asked if they have enough of the 3M tape for MCM mounting. Tom will purchase some and send it to Pisa. In response to a question from Robert, Sandro said that he prefers to mount the MCMs prior to mounting of ladders. However, mounting the ladders first could allow some fine adjustment of alignment of the pitch adapter traces with the ladder strips when the MCMs are mounted.
Tom said that he expects NASA to accept the Redux 312 adhesive (for bonding face sheets to core) within a few days.
Tom reported that Teledyne has 11 boards in the SMT assembly process. At SLAC they have prepared 14 functional PWBs with the thick edge. He intends to get John to machine them today and will send them to Teledyne on Monday. SLAC also need to get the updated parts list and MCM drawings to Teledyne.
Erik reported that Hytec is finishing up preliminary work on CTE issues and investigation of other (non-invar) options. He is writing a report summarizing all of this and will send it out on Monday.
Tom said that the top tray assembly tool is at SLAC but is not yet measured. BJ will look into doing CMM on it. The insert bonding tool is not done but is expected on Friday.
Tom talked about plans to retest the prototype tower with the reinforced bottom tray, probably in January. A decision will be taken next week on which direction to follow (invar vs reinforced carbon-carbon). Erik will check on availability of the BF Goodrich facility for a January test.
Tom predicted that the functional MCMs will be brought to Pisa on the week of Nov. 18. Tom will carry them over himself. Sandro said to bring them to Pisa, as they will test them first in Pisa. (They will also be tested in California before shipping, of course.)