Notes from Teledyne meeting
November 4, 2002
latest MCM PWBs still did not get countersinks in the backside for the
the flight production we need to decide on just one set of holes for the
thermal boards do not need all SMT parts mounted. Only mount those shown on the drawings
for the thermal boards. About 13
boards have already been loaded with all parts, which is okay.
thermal boards do not all need to be wire bonded or even have ICs
mounted. Teledyne only needs to
mount and wire bond enough ICs on the thermal boards, or other dummy
boards, in order to be adequately prepared for production of the
will verify that enough parts remain for the 13 functional boards.
thermal MCM drawings were modified to include the polyswitches instead of
zero ohm resistors. Teledyne
needs DXF files for these new drawings.
needs to know the specifications on the gold body of the functional MCM
will formally notify SLAC of Teledyne’s intention to change the
encapsulation material. The new
material is Hysol FP4450 for fill and FP4451 for dam. Tom will update the materials list.
observed some cracking of the green solder mask on the Young Electronics
boards in the region right around the mounting holes. The cracking only was evident after SMT
mounting. He will investigate this
problem. Possibly it can be avoided
by using the plastic cups on the mounting screws at this stage, to act as
needs more black MCM shipping and handling boxes. Tom will ship at least 30 from SLAC
PWB for the functional MCMs has an error causing inversion of two
differential signals from the controller chips. Teledyne agreed that they can correct this by crossing the
wire bonds. SLAC needs to correct
this on the boards to be made for the flight production.
needs to make wire bonding diagrams for both chips and send them to
Teledyne. The GTRC wire bonding
diagram needs to show the crossed wire bonds.
needs a layout picture of each of the 3 ASICs (GTRC3, GTFE-F2, and GTFE-G)
to use for orienting the chips during die attach.
will Fed-Ex 4 of the new PWBs (without radius) on Tuesday, so that
Teledyne will receive them on Wednesday.
They will be used for programming the pick-and-place and solder
also needs a few more PWBs with radius, in case that the yield is not 100%
for the flex attach.
measured the resistance from power to ground on one of the MCMs assembled
at Teledyne. The results are
to GND = 48 ohms.
to GND = 131 ohms.
to GND = no connection
to GND = no connection
will build half of the functional boards with the G-version GTFE and the
other half with the F-version GTFE.