Minutes of the Tracker Technical Meeting
February 7, 2001
Present: Pisa, SLAC, Hytec, UCSC
Hartmut reported that work needs to be done on the QA section of the SSD specifications. He would like Sandro to review a Word document on detector handling. This will be separate document from the specifications but will be attached to it. The intention is for it to get to the point of test and storage at INFN.
Erik presented a modified drawing of the closeout, with a deeper cutout for the bend of the readout cable arms and a support for the main part of the cable. After some discussion, it was decided that the support area should be 1.5 mm deep, to give ½ mm clearance to the cable. Robert asked about the mass increase in the new design, and Erik said that he would look into it. Robert and Gwelen also noted that pocket cut into the non-electronics closeout side under the cable should be made a bit wider to give us some place to hide a splice in the cable (it is already plenty deep). Erik said that that sounds doable and that he will modify the drawing accordingly.
Tom reported on the engineering meeting at SLAC, for which he will send out minutes.
Hartmut reported that an order has been placed for 600 detectors from HPK, with delivery in April, May, and June.
Gwelen reported on readout cable design. He has found only a single vendor who can do the whole cable in one piece (and that vendor requires rather large vias). He is looking into splicing. It appears that targeting the industry standard 24-inch panel will require two spices in each of half of the cables and one splice in the others. Gwelen will visit 3M in San Jose next week to learn about their process for a thermal-compression splice using z-conductive adhesive.
Sandro reported that he has some visits planned to vendors next week to check on the status of mockup tray production. He will also visit a German firm to learn about their carbon-carbon material. He needs new drawings of the closeout from Hytec, and Erik said that he will provide what they have done so far. He said that they have now a simple panel to use for planarity and thickness tests. They should have mockups in the beginning of March with Kapton and tungsten mounted. They also will have ladders in March using the blank aluminized Si wafers. They have ordered reject detectors in the final design from HPK. In response to Robert’s query, he said that they have not yet started on designing a workholder fixture for trays but are still concentrating on ladders.
Ossie reported on some thermal tests at SLAC. They bonded Si to Al using dot patterns of Nusil 1142-1 and no primer. They used patterns with 23 dots and with 39 dots and used spacers to control the thickness of 150 microns. The adhesive appeared to stick well with no primer. Preliminary results in the thermal chamber indicate negligible transfer of stress into the silicon.
In response to Robert’s query, Tom said that he has not got back to work yet on bias-circuit development.
Erik reported that Hytec has received carbon-carbon material. The next shipment should come at the end of February. The vendor machined the material to take out the warping that occurred during processing. They expect to correct the problem during the next production run. Hytec completed the drawings for the panel assembly tooling and set it out for quotes from 4 shops. The face sheets from PCI are delayed but should be shipped a week from Friday.
BJ reported that he completed mechanical drawings of the 8 readout cables (without splices).
Gwelen reported on progress with right-angle-interconnect prototyping. They tested the encapsulation and found it easy to control to the needed low profile (self leveling).
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