GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
GLAST Large Area Telescope
Gamma-ray Large
Area Space
Telescope
Tracker Subsystem
5B: EEE Parts and Electronic
Packaging
Nick Virmani
LAT EEE parts and Electronic Packaging
Manager
nvirmani@swales.com
(202) - 767 - 3455
5B
Nick Virmani
1
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Outline
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5B
EEE Parts Requirements
EEE Part Implementation Plan
EEE Parts Status
Process Flow for ASICs and MCM Fabrication, Screening,
and Qualification
Radiation Testing
Radiation testing Results
Electronic Packaging Program
ASIC and MCM Documentation Status
EEE Parts Issues & Risk Mitigation
Manufacturing and Test Process Flow of TKR Hardware
Nick Virmani
2
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
EEE Parts Requirements
• Requirements Summary
– Parts screening and qualification per GSFC 311-INST-001,
Level 2,
– Additional requirements outlined in the LAT EEE parts
program control plan, LAT-MD-00099-1
– Review and approve EEE Part Lists.
– Derate EEE Parts per PPL-21
• Review and approve derating information before
drawing sign-offs.
– Perform stress analysis
– Parts Control Board (PCB) Approach, a partnership
arrangement with NASA/GSFC parts engineer and code
562.
5B
Nick Virmani
3
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
EEE Parts Implementation Plan
• Part lists are reviewed and approved by the project PCB prior
to flight procurements.
• Special considerations include:
– Radiation evaluation of all active components
– Radiation testing (TID and/or SEE ) when necessary
– Parts stress analysis
– PIND testing on all cavity devices
– Destructive Physical Analysis (DPA), when applicable
– Mandatory in process inspections and verification on
Multi-Chip Modules (MCMs) and other devices as required
– Life Testing if Quality Conformance Inspection (QCI) data
within one year of the lot being procured is not available
– No pure tin, cadmium, and zinc plating is allowed
– Vendor surveillance where required.
5B
Nick Virmani
4
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
EEE Parts Implementation Plan
• Special considerations include cont’d:
– 50V ceramic capacitors require 850C/85RH low voltage
testing
– Mandatory surge current testing on all tantalum
capacitors
– MCM testing and verification requires special evaluation
as outlined in the EEE parts plan
– Age control requirements. Lot Date Code (LDC) older than
5 years requires DPA and room temperature re-screen
– Parts traceability from procurement to assembly of board
and components.
– GIDEP Alerts & NASA Advisories review and disposition
from selection of parts until subsystem integration.
– Parts Identification list (PIL) includes LDC, MFR,
Radiation information on the flight lot
5B
Nick Virmani
5
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
EEE Parts Status
• The TKR subsystem EEE parts lists have been reviewed by
the PCB all parts have been approved except ASIC
screening, MCM screening, flex cable screening and
qualification, and cristek connectors.
• Resettable polyswitch fuse specification LAT-SS-01116-04
was approved by the PCB and will review test data after
completion of the tests.
• All part test data will be reviewed prior to flight assembly by
the PCB where applicable.
• The goal is to approve the remaining parts on the parts lists
prior to the CDR
• Discuss EEE parts availability weekly, to support fabrication
schedule.
• Perform 100% incoming inspection as per defined
procedures.
5B
Nick Virmani
6
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
EEE Parts Status
• Performed stress analysis of most of the approved parts on
the parts lists and they meet derating criteria after stress
application. Will complete the remaining analysis by the CDR.
• Perform screening and qualification tests as required per
approved procedure.
• Hold regular meeting with GSFC Parts Engineer to resolve
any parts-related issues and approve parts though the Parts
Control Board (PCB).
• Attribute data for screening and lot specific qualification/QCI
data shall be reviewed for acceptance of parts for flight.
• Parts Identification List (PIL) and As-built parts lists is
maintained and will be submitted to GSFC.
5B
Nick Virmani
7
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Process Flow for ASICs and MCM
Fabrication, Screening, and Qualification
WAFERS
RECEIVE
FROM MOSIS
USING
AGILENT
PROCESS
Wafer Probe
100% Sort
dies
INSPECTION
WAFER
LAPPING
MOUNT
PROCEDURE
WAFER
SAW
PROCEDURE
Wafer Probe
Procedure
100%
INSPECTION
DPA & Scanning
Electron
Microscope
(SEM)
Inspection
OPTICAL
QC GATE
CONTROL
MONITORS
FOR
RADIATION
SAMPLE
RADIATION
TESTING
PACK DIE
IN WAFFLE PACK OR GEL
PACK FOR SHIPPING TO
TELEDYNE WITH DATA
PACKAGE & TRACEABILITY
2ND OPTICAL
INSPECTION
Receive/Inspect ASIC die
in waffle or gel packs,
PWBs and parts, record
data at Teledyne
5B
Clean/Bake
PWBs as per
NASA-STD8739.3
Nick Virmani
BOND PITCH
ADAPTER FLEX
CIRCUIT
VERIFY
ADHESION AND
INSPECTION
8
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Process Flow for ASICs and MCM
Fabrication, Screening, and Qualification
5B
Nick Virmani
9
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Process Flow for ASICs and MCM
Fabrication, Screening, and Qualification
Clean Die Bonding
Surfaces of PWB
Plasma and Local
cleaning (IPA)
Die Attach Material
Cure per
Manufacturer’s
Suggestions
Apply Die Attach
Material to PWB
(MCM)
Plasma Clean PWB
and Die Bonding
Surfaces for Wedge
Wire Bonding
COB Die Placement
on the PWB
Wirebond of ASIC
die and MCM PWB
Rework, if required
Install connectors by
hand-soldering
Die Attach Monitor
In Process Wirebond
Pull Testing on
samples and Monitor
100% Optical Inspection
Functional Testing
and verification of
MCM as per test
program *
Rework or replace
dies if required
Encapsulate ASIC
die and bond areas
* Test all register and memory locations, all I/O functions, including LVDS bias levels, all interchip communication, power consumption, all amplifiers by charge injection and test the trigger
output, and for excessive noise or instabilities.
5B
Nick Virmani
10
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Process Flow for ASICs and MCM
Fabrication, Screening, and Qualification
100%
Inspection
Full Functional
Testing using
configured software
test & EGSE
Clean
Conformal Coat
100% Inspect
Full Functional
Testing using
configured software
test & EGSE
Functional
Testing
5B
Pack each MCM
individually in the
ESD container with
pigtail hanging
outside of the
container for testing
100%
Visual
Inspection
MCM ready
functional test &
environmental test
100% Dynamic
burn-in at 85
degrees C with
continuous
monitoring for 168
hours
Nick Virmani
100% thermal
cycling –30 to +85
degrees C,
unpowered
Review results data
package
11
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Process Flow for ASICs and MCM
Fabrication, Screening, and Qualification
100% Visual
Inspection
MCM ready for next
step and sample
selection for
qualification
100% Visual
inspection
5B
Present data to the
Parts Control Board
(PCB) Screening &
Qualification
Select 38 MCMs
from screened lot
Obtain approval
from PCB
Store MCM in
nitrogen purge
storage
Radiograph 2
samples and DPA on
1 sample
100% powered
thermal cycling –30
to +85 degrees C,
100 cycles
100%
Visual
Inspection
Thermal Vac testing
for 10 samples, 12
cycles
100% Dynamic
burn-in testing for
240 hours
Nick Virmani
12
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Process Flow for ASICs and MCM
Fabrication, Screening, and Qualification
Vibration Testing
10 samples
Review of Data
5B
100%
Visual
Inspection
Functional
Testing
Radiograph
CSAM & DPA
PCB Approval
Nick Virmani
13
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Radiation Testing
• All EEE parts are being reviewed by PCB and screened for
radiation susceptibility against the radiation specification
defined in GLAST IRD-433-SPEC-001.
• Requirements:
– Total dose requirement, including standard factor of 2
safety margin is 4.5 Krad (Si) for 5 years behind 100 mils
Aluminum.
– Our goal is to test all parts up to 10 Krads (Si).
– SEE Damage – no SEE shall cause permanent damage to
the subsystem.
5B
Nick Virmani
14
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Radiation Testing
• SEE Rate and Effects Analysis:
– SEE rates and effects shall take place based on threshold
LET (LETth) as follows:
Device Threshold
Environment to be Assessed
LETth < 15 MeV*cm2/mg
Cosmic Ray, Trapped Protons, Solar
Heavy Ion and Proton
LETth =15-37 MeV*cm2/mg
LETth > 37 MeV*cm2/mg
Cosmic Ray, Solar Heavy Ion
No analysis required
SEE immune is defined as a device have an LETth > 37
MeV*cm2/mg
– Our goal is to test each part to this specification.
5B
Nick Virmani
15
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Radiation Testing Results
• Radiation testing was performed on engineering parts
produced using similar processes and materials.
• An earlier version of ASICs tested and met requirements.
• No outstanding issues
5B
Nick Virmani
16
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Electronic Packaging Program
• Electronic Packaging, Manufacturing, Test, and Process
Control program
– Manufacturing, Assembly, and Quality Control of electronic
system will be in compliance to the NASA technical
standards: NASA-STD-8739.1, NASA-STD-8739.2, NASASTD-8739.3, NASA-STD-8739.4, NASA-STD-8739.7, and IPC6012 & 6013.
• Rigid MCM PWBs shall meet the requirements of LAT
Procurement Specification, LAT-DS-01127-01 based on MilPRF-55110, Revision F, and GSFC S-312-P-003 with a minimum
internal annular ring of 0.002”.
• Flex circuit and cables shall meet requirement of LAT-PS01132 and IPC 6013 class 3. Coupons shall be submitted to
GSFC for evaluation.
5B
Nick Virmani
17
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Electronic Packaging Program
• PWB Coupon will be analyzed by GSFC prior to flight
assembly.
• Particular attention will be paid to the quality of workmanship,
soldering, welding, wiring, marking of parts and assemblies,
plating and painting.
• Verification of flight hardware will be performed by NASA
certified and qualified personnel other than the original
operator.
• An item inspection will be performed on each component to
verify:
– Configuration is as specified on each component
drawing/specification.
– Workmanship standards have been met.
– Test results are acceptable
5B
Nick Virmani
18
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
ASIC and MCM Documentation Status
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5B
Wafer Procurement from MOSIS / Agilent
– LAT-PS-1279: Overview
– LAT-PS-1201: Front-end readout chip (GTFE) approved by PCB
– LAT-PS-1222: Readout controller chip (GTRC) approved by PCB
– LAT-PS-1250: wafer probing, review in process
– LAT-PS-01321: wafer lapping, dicing, and inspection, review in
process.
– LAT-TD-1325: Radiation testing, to be reviewed.
Several other documents such as MCM assembly, SMT assembly,
part procurements are in draft format and shall be released by CDR.
Final board prototypes were recently produced and are being
tested:
– PWB: loaded with parts and new ASICs for functional testing
– Pitch Adapter: Teledyne is bonding 3 of them to MCMs to check
that the new design works
– Bias: sent to Italy for review
Nick Virmani
19
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
EEE Parts Issues & Risk Mitigation
• MCM board qualification and handling.
– To mitigate this risk, processes, procedures, qualification
plan, and vendor verification plan is in process and will
ensure they are implemented successfully.
• Pitch adapter flex gluing and alignment accuracy when
bonding to PWB.
– To mitigate this risk, processes will be verified and controls
will be implemented at Teledyne.
• Flight ASICs testing
– To mitigate this risk, all processes and procedures are
being approved. Test software is being improved, which
will be used for verification.
• MCM Assembly and Verification
– To mitigate this risk, manufacturing readiness reviews will
be performed and mandatory inspection points will be
selected.
5B
Nick Virmani
20
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
EEE Parts Issues & Risk Mitigation
• Flex Cable to LAT-PS-01132, defines procurement and
qualification requirements.
– To mitigate this risk EM flex cable will be manufactured to
this specification and will be qualified.
– A visit to the vendor (Parlex) is planned for early April,
together with GSFC representatives.
• Flex Cable Assembly.
– To mitigate risk a detailed procedure being written & EM
flex will be assembled and will be tested prior to flight
production.
• Radiation Testing & Plans
– To mitigate risk GSFC is involved in approving plans but
radiation plans yet not approved.
5B
Nick Virmani
21
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Connectors
• Nano-connectors: Omnetics was recently approved and the
parts are now on order, including the connector savers.
On MCM
On cable
Larger 080
screws
• Micro-D connectors: Kristek connectors are not yet approved,
but we don’t expect any difficult issues.
5B
Nick Virmani
22
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
SMT Parts
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5B
HV capacitors: Novacap
– Procurement spec: LAT-PS-01194
– On order for the Tracker and Calorimeter
Polyswitches: Raychem (Tycho)
– Procurement spec: LAT-SS-01116
– A sample lot was already procured and all testing performed, so
no surprised are expected in the flight lot
– Recently finalized and approved, and the parts are on order
– Long process of testing at UCSC and discussions with the vendor
• 100% of parts: screening after thermal cycle
• 10% of parts: more extensive tests after soldering
• Smaller sample for qualification testing at UCSC
Ceramic & tantalum capacitors: approved with no issues
Resistors: approved with no issues
Thermistor: approved with no issues
Nick Virmani
23
GLAST LAT Project
TKR Peer Design Review, Mar 24-25, 2003
Manufacturing and Test Process Flow
for Tracker Hardware
Pre-Production
-Initial Quality Planning
-Design Reviews
-Critical Components
-Documentation Reviews
-Lessons Learned
-Quality Criteria
-Design Requirements
-Workmanship Standard
-Training and Certification
Procurement
Fabrication
-Pre-award surveys
-Supplier Evaluation
-Purchase Document Review
-Source inspection where
applicable
-Critical Components
-Nonconforming Material
Control
-Manufacturing Reviews
-Work instructions and
procedures
-Calibration
-Process Readiness
-Nonconforming Material
Control
-Inspection
-Material Review Board
-Audits
Integration & Test
-Work instructions,
procedures, and travellers
-Audits
-Configuration verification
-Inspection
Storage &
Shipping
-Test Readiness Review
-Nonconforming material control
- Previous Operation Audits
-Component Data/Subsystem
packages
-Test Procedures
-Test Monitoring
-Data Review
-Closeout of open NCMRs.
5B
Assembly
-Storage and Shipping
Requirements
-Inspection and storage
shipping controls
-Data Package Reviews
-Audits
Nick Virmani
24