GLAST LAT ProjectMarch 24, C Tracker Peer Review, WBS GLAST Large Area Telescope: Tracker Subsystem WBS C: Electronics Module Testing Robert Johnson Santa Cruz Institute for Particle Physics University of California at Santa Cruz Tracker Subsystem Manager Gamma-ray Large Area Space Telescope

GLAST LAT ProjectMarch 24, C Tracker Peer Review, WBS Overview Draft test plan: LAT-TD High yield and good quality of MCMs requires testing at several levels during the production: –Printed Wiring Board: full test against the netlist by flying probe –Parts screening specified in several procurements: Polyswitches (LAT-SS-01116) Nano Connectors (LAT-DS-01807) HV Capacitors (LAT-PS-01194) Standard QML SMT parts –Wafer probing of the GTFE and GTRC ASICs (Presentation 5D) –MCM testing after SMT parts and connector soldering –MCM functional tests after die attach –MCM thermal cycle and burn-in –Final acceptance test

GLAST LAT ProjectMarch 24, C Tracker Peer Review, WBS MCM Testing at Teledyne Test system and software supplied by UCSC/SLAC. Initial power-on test after soldering but before die attach. –Check for shorts in the power bussing. –Check for leakage on the SSD bias-voltage line. Complete electrical test after die attach and wire bonding but before die encapsulation (see also Presentation 6E). –Functional test –Power consumption –Basic amplifier-discriminator performance VME with COM Card and ADC Frequency Counter Adjustable Clock PC MCM DUT Interface Card (with cover removed)

GLAST LAT ProjectMarch 24, C Tracker Peer Review, WBS Test and Burn-In This work will be done in the SLAC clean room in Building 33. The MCMs remain in their closed storage boxes throughout this procedure. A functionality test is done to check that no damage occurred during encapsulation. 9 MCMs are connected to a pair of special flex-circuit cables (1 is shown at right, with a repeater board). 4 such cables pairs are installed in a climatic chamber. 8 long cables attach to the repeater boards and exit the chamber, to connect with a TEM. The 36 MCMs are thermal cycled through the required acceptance cycles. The temperature is raised to 85°C for 336 hours for burn-in. During this time the electronics are continually exercised and tested.

GLAST LAT ProjectMarch 24, C Tracker Peer Review, WBS Further MCM Testing Final Acceptance Test: performed in Italy prior to bonding of the MCM to the edge of a tray panel. Test after wire bonding to the bias circuit but prior to mounting of SSD ladders. –Checks for shorts or leakage in the SSD bias path. –Final check of the tray before committing expensive SSD ladders. Test after completion of tray assembly. –First test with input load on the amplifiers. –Preliminary catalog of dead or noisy channels. Cosmic-ray testing of stacked trays (still in their service boxes). Tower electrical testing (test plan = LAT-TD-00191).