durability growth through halt hass testinghalt/hass and accelerated testing halt testing design...

HALT/HASS and Accelerated Testing

Durability Growth through


Elite Electronic Engineering


Topics Covered

Review Your Requirements

Overview of Accelerated Stress Testing

HALT

HALT Equipment, Test Methods, Expectations

HASS

Other Accelerated Tests

Summary

Q&A


Test Requirements & Goals

Is Testing Desired by Manufacturer to

Reduce Cost of Development,

Manufacturing, and Warranty Obligations?

Mandated by Manufacturer’s Client?

What are your expectations and goals for

this testing?


New Product Development Testing Screens

Qualitative Testing

Qualification

Testing Qual Retest

Quantitative Testing Manufacturing

Screen

New

Product

HALT, HAST, ESD,

Power Cycle, EMI RTCA DO-160

MIL-810,

SAE J1455

Temp, Vibration, Shock,

Waterproofness,

Altitude, Humidity

HASS Analysis

Phase

Development

Phase


Quantitative Testing

.95 .80

.98

.65

.98

Reliability Block Diagrams

=0.73

Success Run Testing

Test to Failure- Weibull


Which Tests To Run

Input from all departments

Determine failure modes (FMEA)

Consider complete life cycle of product

Suggest stresses that will precipitate failures Maximum Stress vs Time Dependent

Develop test plan

Execute test


Time Dependent Failure Mechanisms

Loss of signal Silicon Diffusion Temperature

Power Failure Dielectric Breakdown Electric Field

Loss of signal Electromigration Temperature & Power Cycling

Intermittent Output Corrosion & Oxidation of

Fractures

Humidity, Voltage, Temperature

Loss of signal Dendrite Growth Humidity, Temperature

Water Intrusion Seal Leaks Pressure

Cracked Solder

Joint

Fatigue Thermal cycling & vibration

Failure Mechanism Accelerating Factors Failure Mode


HALT Testing (Qualitative)

Highly Accelerated Life Testing (HALT)

Temperature and Thermal Shock (60C/min)

Vibration 6 axis simultaneous (6 DOF)

Very high stress levels to achieve time compression & quickly find the weakest links.

Additional stresses likely to precipitate flaws can be used as a part of the HALT/HASS program.

power cycling, voltage /electrical stress


HALT Testing

Design Optimization Provide data to designers for risk assessment

Weak links- opportunity to improve the product before the design is “locked in”.

Build in lifetimes of use in its field environment, “very large margins”.

Proactive technique focusing on the mode and mechanism of failure, not on the specifications or the level of stress.

No pass/fail criteria HALT specification. Some HALT specifications describe a “common method”

Product Comparisons Side-by-side evaluation of various products and product revisions under similar

extreme stress

HASS Endpoints Large margins enables the use of high levels of stress in the HASS screen. Leave

several if not many lifetimes of use remaining in the product.

Enables the use of HASS to quickly detect any slippage that might occur in the manufacturing process.


HALT Testing


HALT Testing

Halt Chamber

Workspace 42”x42”x40”

Heating & Cooling

-100C to +200C

>60C/min depending

on product loading and

temperature range


HALT Testing

Heating

Elements

Nichrome

Coils

FLA 135A

Min Service

175A

460VAC 3ph

Airflow

4,000CFM


HALT Testing

LN2 Cooling

4.5GPM

30 PSIG


HALT Testing

RS Vibration Table Multi-axis repetitive shock

3 linear, 3 rotational Axes

2Hz-10,000Hz

Up to 60GRMS

(depending on loading)

Table Size 30” x 30”

Payload up to 400lbs

(reduced vibration amplitude)

Compressed Air

90PSIG, 48CFM


HALT Testing

RS Impactors


HALT Testing


HALT Testing

HALT PSD

1.E-06

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.0E+00 1.0E+01 1.0E+02 1.0E+03 1.0E+04 1.0E+05

Frequency (Hz)G^

2/H

z


HALT Testing

Ckt board resonant frequencies

Components on PWB

Chip capacitors and die bond wires


Feb 11, 2005 10:23:11

Demand: 6.061 G

Control: 6.06 G

Level 1) 100%

Level Time: 0:05:00

Total Time: 0:05:22

Output: 0 V RMS

End of Test

Ice Corporation (33141)

De-Icing Control Unit (9510 Rev T)

Y Axis sn: C350-00057-SAC

20 2000100 1000

-31x 10

-21x 10

-11x 10

Demand

Control

Frequency (Hz)

Acc

eler

atio

n (G

²/H

z)

Acceleration Profile

RS vs. ED


RS vs. ED

ED (Electrodynamic Vibration) Controllable Vibration Spectra

5Hz-2000Hz

Single Axis

2” Displacement

RS Random Only

6 Axis

30Hz-10,000Hz

10x -15x higher peak accel vs. ED


STEP 1: Pre-HALT Planning

Discuss product with multi-functional team

Develop test plan

Bench test to confirm operation before starting HALT

Steps Involved with HALT


HALT Process

STEP 2: Preparing for the HALT

Setup

Design appropriate vibration fixture

Tune chamber proportional & integral parameters

Configure air flow for maximum product temperature

change rate

Apply thermocouples and accelerometers to device

under test

Setup functional test equipment


HALT Process

STEP 3: Thermal Step Stressing Cold

Begin at ambient

Step down in 5°C or 10°C increments

Use caution as fundamental limit is approached

Approximate dwell time of 10 minutes at each temperature

Allow sufficient time to run functional tests

Find and fix failures

Verify operation of thermal safeties

Disable safeties to determine actual operating & destruct limits

Continue until fundamental limit of technology is reached

Practice continuous failure monitoring


HALT Process

STEP 4: Thermal Step Stressing Hot

Begin at ambient

Step up in 5°C or 10°C increments

Use caution as fundamental limit is approached

Approximate dwell time of 10 minutes at each temperature

Allow sufficient time to run functional tests

Find and fix failures

Verify operation of thermal safeties

Disable safeties to determine actual operating & destruct limits

Continue until fundamental limit of technology is reached

Practice continuous failure monitoring


Limits Encountered in HALT

Stress

Lower

Operating

Limit

Margin

Operating

Product

Specs

Lower

Destruct

Limit

Destruct Margin

Upper

Operating

Limit

Margin

Operating

Upper

Destruct

Limit

Destruct Margin

Data from Gregg Hobbs of Hobbs Engineering


HALT Process

STEP 5: Rapid Thermal Cycling

Transition temperature at maximum product temperature change

rates

Select temperatures 5°C inside upper and lower operational limits

Reduce change rate by 10°C/min if product cannot withstand

maximum rate

Continue thermal cycling until operating limit (°C/min) is found

Continue cycling for a minimum of 10 minutes

Apply functional testing and continuous failure monitoring

Depending on the product or application, this step is sometimes

omitted


HALT Process

STEP 6: Vibration Step Stress

Understand how product responds to vibration input

Vibration is stepped-up in increments, normally 3-5

Grms on the product

Dwell time of 10 minutes at each level is typically

sufficient

Start dwell once product reaches vibration set point

Continue until operational or destruct limit is found

Apply additional product stresses during process


HALT Process

STEP 7: Combined Environments

Develop thermal profile

Use established thermal operating limits, dwell times and change

rates

Incorporate functional tests and continuous failure monitoring

Begin with constant vibration level of approximately 3-5 Grms

Step up in 3-5 Grms increments upon completion of each thermal cycle

Use tickle vibration when higher Grms levels are reached

Add 3-5 Grms tickle to determine if failures were precipitated at high G level but only detectable at lower G level


Suggested HALT Process Per GMW 8287


The Product Determines the Stress

Power Cycling

Output Loading

Voltage/Electrical Stresses

Humidity (HAST)

Pressure

Altitude

Corrosion

Other Stresses


HALT Process

STEP 8: Lessons Learned

Determine root cause of all failures that occurred

Meet with design engineers to discuss HALT results

Management cost justification & risk assessment

Determine and implement corrective action

Perform Verification HALT

Insure problems are fixed and new problems were not introduced

Periodically evaluate product as it is subjected to engineering changes


HALT Testing

Other considerations Quantity of Samples

Product Improvement

Preparation for HASS/HASA

Comparison Testing

Fixturing

Stimulation vs. Simulation

Product and Fixture Weight

Test Uniformity

Lower

Operating

Limit

Margin

Operating


HALT Testing

Cross Table Uniformity

69.364.0

45.2

60.065.5

136.3

130.0

93.3

128.4

136.1

17.9

12.9

10.8

14.7

16.3

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

1 2 3 4 5

Table Location

25 &

55 G

rms I

np

ut

Scale

0.0

5.0

10.0

15.0

20.0

25.0

5

Grm

s I

np

ut

Scale

25 Grms Input55 Grms Input5 Grms Input


HALT Testing

Response Level

Test Location Control Level Grms- X Grms-Y Grms-Z Mean

1 5 21.2 19.2 13.4 17.9

1 25 79.8 73.0 55.0 69.3

1 MAX (55) 158.1 138.3 112.6 136.3

2 5 14.2 14.6 9.8 12.9

2 25 73.3 68.4 50.3 64.0

2 MAX (55) 150.1 134.2 105.6 130.0

3 5 10.5 13.8 8.1 10.8

3 25 42.6 55.6 37.3 45.2

3 MAX (55) 85.5 113.6 80.7 93.3

4 5 16.6 17.4 10.1 14.7

4 25 68.1 67.5 44.5 60.0

4 MAX (55) 145.3 140.3 99.7 128.4

5 5 19.1 18.4 11.3 16.3

5 25 77.1 69.5 50.0 65.5

5 MAX (55) 157.4 140.5 110.5 136.1

1 5 20.5 17.9 12.1 16.8

1 25 75.1 72.3 51.9 66.4

1 MAX (55) 158.1 140.7 112.8 137.2


HALT Testing


HALT Testing

Failure Analysis Services


HALT Testing

“SEM photographs showing and overall view (top, ~40x) and a typical

closer view (bottom, ~800x) showing some surface debris but no

damage to the integrated circuit from sample D4.”

Failure Analysis Services


HALT Testing


Component Selection

Did vendor perform HALT AND HASS?

Use to verify products operating limits.

Use to select most robust product.

Vendor Selection

If subcontracting, vendor needs to meet your

standards (Halt and Hass equipment, should

be the same.)

Other Uses of HALT


HASS- Highly Accelerated Stress Screening

HASS is used as a production quality screen

quickly identify any weaknesses that might enter the

product due to changes or malfunctions in the

manufacturing process.

Each weakness detected, represents an opportunity

to take corrective action prior to shipping large

quantities of flawed product.

The screen is “tuned” so that it detects weak product

while still leaving several, if not many lifetimes of

field use in the shipped product.


HASS Testing

HASS- 100% Production Screening

HASA- 1-10% Production Auditing

Safety of of HASS

Repeat screen a minimum of 20 times

Assuming remove less than 5% life

Failures after less than 10 times, too harsh

Re-HALT- Confirm margins


Other Accelerated Stress Testing

Acceleration Factors

Temperature

Arrhenius Model

Humidity

Arrhenius-Peck Model

Vibration

Miner Criteria

Voltage

Inverse Power Law

Product Life Cycling

CALT Testing

Test to Failure & Apply Weibull Analysis



Calibrated Accelerated Life Testing (CALT)

Suggest primary fatigue mechanism

Simulate loads at three stress levels

90% of foolish load (first test)

80% of first test load

Third stress level

Depends on first two and ultimate life

Test all units to failure

Plot S-N curve, Determine AF’s

Generate Weibull Plot



Accelerated Life Testing

•“Accelerated Testing: Statistical

Models, Test Plans, and Data Analysis”

•By Wayne Nelson

•CALT GMW 8758

•Example

Automatic Lubricating System


CALT Test Example

•Simulate loads

at three stress

levels

•Monitor test

counting cycles

to failure


CALT Test Example Stress Cycles To Failure

36 3121

36 1075

36 629

36 9452

31 11386

31 1104

31 6624

31 1577

25 11044

25 15405

25 19257

25 28723

Pump S-N Curve

y = 3050953219559.39x-5.93

100

1000

10000

100000

10 100Applied Stress (PSI)C

ycle

s t

o F

ailu

re

•Collect Failure Data

•Plot and determine Inverse

Power Relationship

•AF = (Saccel/Snormal)b

Determine AF's

Condition

High Stress

Mid Stress

Confirm Stress

Normal Stress

Accel Factor

180

74

21

Stress Value (PSI)

36

31

25

15 N/A


CALT Test Example

Stress Level Test Stress Accel Factor Rank

High (IG) 3121 180 9

High (IG) 1075 180 4

High (IG) 629 180 2

High (PP) 9452 180 12

Medium (PP) 11386 74 11

Medium (IG) 1104 74 1

Medium (PP) 6624 74 8

Medium (IG) 1577 74 3

Confirm (PP) 11044 21 5

Confirm (PP) 15405 21 6

Confirm (PP) 19257 21 7

Confirm (PP) 28723 21 10

Cycles at Normal

Stress

560979

193224

113059

1698933

398246

594009

843189

81757

490540

116785

228397

318585

Median Rank

5.61

13.60

21.67

29.76

37.85

45.95

54.05

62.12

70.24

78.33

86.40

94.39

81757

228397

594009

843189

1698933

Sorted Least to Most (Resort these numbers for each

change to spreadsheet)

318585

398246

490540

560979

113059

116785

193224

Sort and apply median ranks

Generate Weibull Plot


CALT Test Example

Weibull Plot

•Obtain distribution parameters

•Reliability metrics

•B1, B10

•Reliability vs life

•Reliability Block Diagrams

ReliaSoft Weibull++ 7 - www.ReliaSoft.com

Probability - Weibull

Time, (t)

Unre

liabi

lity,

F(t)

10000.000 1.000E+7100000.000 1000000.0001.000

5.000

10.000

50.000

90.000

99.000Probability-Weibull

Data 1Weibull-2PRRX SRM MED FMF=12/S=0

Data PointsProbability Line

Steve LayaElite Electronic Engineering6/12/20084:58:49 PM


HAST Testing

Accelerated Humidity Testing

•HAST (Highly Accelerated

Stress Testing)

•JESD22-A110 B

•Compress 1000 Hour 85/85

Humidity to 96 Hours

•High Temperatures may

stimulate uncorrelated failures

•Arrhenius-Peck Accelerated

Model for Temperature

Humidity


HAST Testing

“…Photographs showing environmental damage to the solder

joints of A8.”


Instrumentation & Data Acquisition

Yokagawa DL708 Scope

Ten Systems In-House

4, 8, and 16 Channel

LeCroy Digital Storage Scopes

1.5GHz Bandwidth, 8GS/s, 16M data points

Seven Systems In-House

400MHz, 500Mhz scopes

Agilent 34970A Data Acquisition System 120 Single Ended or 60 Differential Input

AC/DC, Volts, Amps, Frequency, Ohms


Advanced Material Center

Materials Testing and Failure Analysis

Physical Testing

Thermal Testing

Chemical Testing

Light & Appearance

Exposure Testing

Product Comparisons

Location: Ottawa, Illinois

www.amc-testlabs.com



Physical Testing

Tensile

Tear

Dart

Flextural

Friction

Surface Tension

Specific Gravity

Density

COF



Thermal Analysis

Differential Scanning Calorimeter

(DSC)

Melt range

Purity

Thermal Mechanical Analyzer (TMA)

Expansion/Contraction

Thermal Gravimetric Analyzer (TGA)

Thermal degradation

Ash


Materials Engineering Incorporated

Complete Metallurgical Laboratory Failure Analysis

Analysis of Processing Problems

Contamination Identification

Engineering Support/Consulting

Laboratory Testing

Specialized Testing

Litigation Support and Expert Testimony

Location: Virgil, Illinois

www.materials-engr.com


Materials Engineering Incorporated

Complete Metallurgical Laboratory

Scanning Electron Microscope (SEM) with EDS

OES Chemical Composition

Metallography and Microscopy

Microhardness and Hardness

Electrical Conductivity

Density/Specific Gravity

Surface Roughness (Ra)

Pressure and Torque Testing

Specialized Product and Component Testing

ISO 17025 Accredited by A2LA


Other Tests to Failure


Durability Growth to HALT HASS

Any Questions?

Thank You!

durability growth through halt hass testinghalt/hass and accelerated testing halt testing design...

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