Imagination at work.
Emad Andarawis, David Shaddock, Liang Yin Presenter: Nancy Stoffel
High Reliability, Harsh Environment Electronics ECTC 2017
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High Reliability Harsh Environment Electronics
Performance challenges at high temp: •Parameter shifts over temperature and time •Integration potential
Reliability challenges at high temp: •Industry driven by O&G: 1-2K hours of life at 210-225C •Long Un-accelerated testing time (Years!)
Reliability and performance go down with temperature, so does our ability to assess them!
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High temp reliability and challenges
Delamination @ temp
Via Barrel cracking Corrosion due to
flame retardant
Thru-hole solder failures (HMP)
Crack
Trace Solder
Surface mount solder failures
On-chip via current density
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Reliability assessment approach and test capabilities
Screening Accelerated life testing
Model parameter extraction
Life Prediction
Failure Analysis
ReliaSoft ALTA 7 - www.ReliaSoft.com
Life vs Stress
TiW\Data 1: Beta=4.4208; B=1.1887E+4; C=2.9776E-5TiWMo\Data 1: Beta=3.8180; B=2.0983E+4; C=1.1984E-11
Stress
Life
790.000550.000 598.000 646.000 694.000 742.0001.000
1000000.000
10.000
100.000
1000.000
10000.000
100000.000
LifeCB@90% 1-Sided TB
TiWMo\Data 1ArrheniusWeibull572F=16 | S=6
Eta LineTop CB EtaBottom CB Eta
573.15Eta PointImposed Pdf
678.15Stress Level PointsEta PointImposed Pdf
713.15Stress Level PointsEta PointImposed Pdf
773.15Stress Level PointsEta PointImposed Pdf
TiW\Data 1ArrheniusWeibull572F=17 | S=3
Eta LineTop CB EtaBottom CB Eta
573.15Eta PointImposed Pdf
678.15Stress Level PointsEta PointImposed Pdf
713.15Stress Level PointsEta Point
HTS to 260 ˚ C
Thermal shock chambers -70 to 350 & 370˚C HTS to 704˚C High Temp Vibration to 300˚C
Validation
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High Temperature Circuit Substrates
Laminates attractive from cost, circuit density and assembly perspective. Suitability for high temperature, high reliability applications unknow. Screen laminates with common circuit board test methods: via thermal cycling, weight loss, peel strength, and surface insulation resistance (SIR). Materials selected from those with high Tg(>250˚C), low CTEz, and modulus.
Cost Feature size
Lifetime above 200C
CTE to Semiconductor
Circuit Density
Second level assembly
Thermal conductivity
Circuit board laminates (FR-4)
Thick film/Al2O3
Thin film/AlN
LTCC
HTCC
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Isothermal Aging at 200˚C Images Polyimide 1 Polyimide 2 Polyimide 3 PTFE
0 hours
4000 hours
5000 hours
6000 hours
Polyimides have little remaining structure after 5000 hours (~5%wt loss). PTFE is still surviving >8000 hours at 200˚C.
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Secondary Creep Test Results
Seco
ndar
y Eq
uiv.
Stra
in R
ate
(1/s
)
Von Mises Stress (MPa)
6
4
Temperature
MTS Test Frame
Solder Model Characterization Controllable Parameters: • Stress level • Strain rate • Load amplitude • Temperature • Multiple strain-range modes
𝑁𝑓 =𝜃∆𝑊
∝
ε p (plastic strain)
σ (s
tres
s)
έ (Strain rate)
T (Temperature)
Elastic-Plastic Tests
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Reliability model development example: Passives Test Setup
Fixture Wired in Furnace
Physics of Failure Models
Simulated Failure Rates
HALT, Step Stress Testing
Reliability DOE
Device Loads
Load Factors
Life Model Prediction
Mean Life Validation
Design Limits
DOE Levels
What are the model coefficients?
How good is the prediction?
−
=
211
2
2
1 11expTTk
EVV
tt a
nFailure Model: Prokopowicz equation
ReliaSoft ALTA 7 - www.ReliaSoft.comProbability - Lognormal
Std=0.3589; B=3.3687E+4; C=6.9597E-16; n=3.9307
Time
Unre
liabil
ity
0.100 100000.0001.000 10.000 100.000 1000.000 10000.0001.000
5.000
10.000
50.000
99.000Probability
Selected Data_2Temperature-NonThermalLognormal573|50F=5 | S=4
Stress Level PointsStress Level Line
573|100F=10 | S=0
Stress Level PointsStress Level Line
573|200F=10 | S=0
Stress Level PointsStress Level Line
598|50F=9 | S=0
Stress Level PointsStress Level Line
598|100F=6 | S=0
Stress Level PointsStress Level Line
598|200F=10 | S=0
Stress Level PointsStress Level Line
573|25Use Level Line
David ShaddockGeneral Electric Global Research6/14/20112:42:30 PM
Reliability versus stress factor
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Summary
• Reliability and performance degrade as temperature increases • Life prediction models don’t adequately cover operation above
conventional (~125C) temperatures • High reliability applications require test time acceleration • A number of existing device and packaging options target short
duration use.
• Reliability assessment and modeling approach was developed • Life prediction and acceleration models at extended
temperature.