- About 1300 ladders with good IV curves are complete (about 9 towers)
- 248 more are ready for electrical testing
- 260 are in fabrication
Bias Circuits: 571 out of 850 delivered by Parlex.
- Plyform is continuing with fabrication of tray panels.† About 90 bare tray panels have been fabricated to date (over 25% of the total).† 21 finished trays have been delivered (not counting the test articles), and 20 passed the thermal-vacuum test (one failed with complete debonding of the primer from two thin tungsten tiles).
- GSFC is processing tungsten tiles through etching and priming.
- G&A finalized the new MCM bonding procedures (revised to ensure connector clearance) and completed two flight trays.
- One tray with MCMs bonded (but no SSDs yet) has a problem with no bias from the MCM to the two center ladder attachment points on the bias circuit.† The cause is not yet known, but a new procedure is being introduced at SLAC to probe test delivery of bias voltage to all bias wire-bonding pads on the pitch adapter before shipping to Italy (the normal automated test sequences donít verify this until detectors are attached).
The Tower-A sidewalls are complete and in
- A second set of sidewalls is nearing completion.
All of the flight-build prepreg is made, and we are
working on getting it to
- Work is in progress at SLAC to clean conformal coating off of connectors on MCMs to be delivered end of next week for Tower B.
- Work is still in progress to get Teledyne back on line with the MCM production.
- Visual inspection and manual probing of pitch adapters is continuing while work proceeds in implementing the more automated electrical test into the production.† About 14% of MCMs are being lost to cracked traces, which is too many.† Parlex is late in delivering all the new-design pitch adapters that we need to test, hopefully avoiding trace cracking.
- DDI presented (likely) cause and corrective action for the short circuits observed in several MCMs from one lot of prepreg material.
Flex Circuit Cables
- Work proceeds on getting prototype cables from two new vendors, one of the two cases being long cables spliced from pairs of shorter cables.
- Serious workmanship and QA problems have now been found with Parlex cable assembly (gluing and soldering connectors, etc) and a stop work has been put on the assembly operation.† This is a serious problem for Tower-A: we do not have a set of flight-worthy cables.
- The work shutdown at SLAC halted work on a number of GSE items needed for tower assembly and shipping.† That work has been moved off-site now, and it appears that we will have everything just in time.