Transcript Section 7.C - Electrical Testing

GLAST LAT Project
March 24, 2003
GLAST Large Area Telescope:
Gamma-ray Large
Area Space
Telescope
Tracker Subsystem
WBS 4.1.4
7C: Electronics Module Testing
Robert Johnson
Santa Cruz Institute for Particle Physics
University of California at Santa Cruz
Tracker Subsystem Manager
[email protected]
7C
Tracker Peer Review, WBS 4.1.4
1
GLAST LAT Project
March 24, 2003
Overview
• Draft test plan: LAT-TD-00249
• 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
7C
Tracker Peer Review, WBS 4.1.4
2
GLAST LAT Project
March 24, 2003
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
Interface Card (with cover removed)
VME with COM Card and ADC
Frequency Counter
PC
MCM
DUT
7C
Adjustable Clock
Tracker Peer Review, WBS 4.1.4
3
GLAST LAT Project
March 24, 2003
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.
7C
Tracker Peer Review, WBS 4.1.4
4
GLAST LAT Project
March 24, 2003
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).
7C
Tracker Peer Review, WBS 4.1.4
5