Highly accelerated Life Testing HALT in Barco

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Highly accelerated Life Testing

HALT in Barco

2007

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HALT in Barco

Topics

• Situating HALT in Barco • How it started

• Current situation: The HALT Installation itself

• Situating HALT in the Design Process ? • The HALT Procedure

• Practical Tips • Operating Cost • Other HALTs

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Temperature cycling only on Qualified units

Target 1: 500 hours before release of design Target 2: 3500 hours in total

manufacturing release if:

- 500 h

- If all malfunctions have a root cause analysis and a corrective action is implemented.

0 9 4 6 7 8 5 3 2 1 10 11 12 14 13 17 15 16 18 10 0 1 1 5 6 7 8 9 11 1213 1415 16171819 20 2122 23 24 2 3 4 5 70°C 25°C -10°C -20°C 2

It needs to be taken into account that condensation occurs after one hour at 25°C. HIGH ACCELERATED LIFE TEST PROFILE

POWER OFF

POWER ON

-10ºC to 70ºC: 2cycles/day. 70ºC to -10ºC: 3 cycles/day. 21 hours operational/day.

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The installation itself

• In the lab

•

Chamber itself ………

•

Pipes Inside ………...……..…

•

Safety aspect

• Outside the lab

• Pipes External ………

• Thermal isolation by Vacuum

•Liquid Nitrogen Tank …...…

• 5000 L (4500 L useful)

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• For new or derived products

• During the Design and before

final qualification.

• To compare same product of

different competitors

• For finalized products

• To simulate field failures

Business Case Evaluation Preliminary Design Prototype/ Alpha stage Pre-series/ Beta stage Series Phase-out Pre-Study BCR PDR CDR FQR POR CLR SRR EOL 1. Board level assemblies

2. Electronic/ Electromechanical Equipment

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1. Define a HALT team with multiple disciplines (Project Leader, Mech. resp, Elect. resp, Test executer)

Mech. Resp. and Elect. Resp: looking for root causes and implement corrective actions

2. Define the EUT and how to test (closed, open, cabling, …),fixation

3. Get the Operating Temperature and Vibration specifications

(from Marketing/Sales or Customer) ……….. 4. Define the Target Operational Limits for Temperature and

Vibration ……….. 5. Make an FMT(Functional Monitoring Test) and define the

coverage (must cove at least the major functionality) ………….… 6. Check LN2-Volume left before extensive testing.

7. Fix the EUT in the chamber ……….

Vibration Jig: stiff (transferring vibration energy at all frequencies) low thermal inertion (cooling and heating rate) open structure (air flow)

low weight (G level)

minimum number of resonances

8. Connect the accelerometers and the thermocouples ……….

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During HALT

1. Continuously perform the FMT (it is not a humidity test !) 2. Monitor all HALT Parameters as a function of time (Temp, Vibr,

FMT,…)

3. List the deviations, if any

What should be corrected / what not (LCD clearance, Deformation of plastic housings, …)?

• Perform root cause analysis • Implement a corrective action

• Cost of corrective action (time and material) ?

• Delay in product release ?

• Risk of non-implementation ?

• Benefit for other products ?

• Fundamental limit of technology ?

• Perform a verification HALT

Note: Do not “explain issues away” as this does not improve the reliability. It is a repeated “Stress – Fail – Fix” process.

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1. Thermal Step Stress Test LTOL UTOL Start at ambient Temperature 10 °C Decrements Minimum dwell time = 12 minutes FMT 45 °C/min

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2. Rapid Temperature Cycling

3. Vibration Step Testing (VOL)

Minimum 3 thermal cycles UTOL – 5°C LTOL + 5°C Minimum dwell time = 10 minutes Start at 5 gRMS 5 gRMSIncrements Minimum dwell time = 12 minutes FMT

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4. Combined Testing

5

Temperature cycles

UTOL – 5°C

LTOL + 5°C

Target is 5 complete combined test cycles.

FMT

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5. Thermal Step Stress Test (if no Destructive Limits are encountered during previous testing)

LTDL

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After HALT

1. Make report (Report should be finished as Test is finished) • Product identification

• Description of product fixture • Location of response sensors

• Deviations from the standard HALT process

• FMT

• Detail of occurrences of unit degradation

• Root cause analysis + Corrective actions implemented (Resulting in Engineering Changes)

• Summary of reached levels

2. Store all HALT data (so that the test sequence can be reproduced afterwards).

3. Clean up.

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• HALT in Barco is considered as being successful

when:

• target limits are reached,

• when failures occur, the failures are understood, • corrective actions are taken,

• the product limits are clearly defined and pushed as far as possible.

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• have knowledge of the equipment

• LN

2

Storage

• LN

2

Pressure stabilization

(how it works)

• Max cooling performance versus max efficiency

• Air pressure & Flow rate

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• Renting of the LN

2

tank

• LN

2

Consumption

• Electricity / Compressed air

• Operator

(Almost Full Time)

LN2 Consumption 0 1000 2000 3000 4000 5000 6000 29/Dec/ 2004 17/Feb/2 005 8/Apr/20 05 28/May/2 005 17/Jul/2 005 5/Sep/2 005 25/Oct/2 005 14/Dec/ 2005 2/Feb/20 06 24/Mar/2 006 13/May/2 006 time [-] L N 2 C o n s u m ti o n / d a y R e fi ll V o lu me [ L] 0 500 1000 1500 2000 2500 3000

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AVIONICS

1. Unit 1: UnderfillSimulation of BGA failure in the field. Broken connections underneath QUASAR chip 2. Unit 2:

3. Unit 3:

• 3 Ethernet failures have occurred during the test: • Abnormal flickering image on the display

• The unit reboots automatically when this failure occurs.

• Combo card is resetting at random (this reset is typically triggered by the main processor board)

• Front of the EUT appears to reboot at random.

•The bottom plate of keyboard tablet has become loose during the Vibration Operation Limit (VOL) test

•Coil L6 (part of 3V3 switching regulator) has become loose from

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DEFENCE

• Unit 1:

• Unit 2:

• Light leak on top of the unit that has become worse during the Short Term HALT. • Bad contact in the LCD connector (J5) on the PDB-Board of the Unit.

• Electrolytic capacitor C388 on the VPB-Board of the VCM-1102 that has shortened. • Isolation of the VECTORLINK cable on the PM-side does become loose.

• one or more backlight lamps are not functioning anymore. • Bad contacts electrolytic capacitors

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MEDICAL

• Unit 1: Backlight (test of cracks in Light Guide)

• Unit 2: (with witnessing)

• A vertical tab is broken after about 3 minutes • light-leaks are visible at the bottom of the display • 5 electrolytic capacitors have broken off • Optical link does not function anymore • USB link does not function anymore

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• Rapid Voltage variation

(determination of the Voltage margin)

• Power (On/Off) cycling

(5000 cycles and perform FMT after each 500 cycles)

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•

During manufacturing, based on a “finished design”

•

Replaces the current Temp. Screening (Burn-in)

•

The limits discovered during HALT are used as the basis for setting the HASS parameters

•

Detect weaknesses that are possibly introduced during manufacturing (done on a finished product).

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Shorter screening time (5 hours instead of 24 or 48 hours)

•

Based on same equipment (with or without vibration).

•

Check differences between chambers (T° and Vibration capabilities). Business Case Evaluation Preliminary Design Prototype/ Alpha stage Pre-series/ Beta stage Series Phase-out Pre-Study BCR PDR CDR FQR POR CLR SRR EOL

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UTOL+20°C UTOL-10°C Ambient temperature LTOL+10°C LTOL Time [min.] Temperature [°C] 0.8 * VOL 0 Vibration [Grms] Time [min.] VOL 5 12 12 1215 30 5 30 51515 0 60 120 180 15 30 5 30 530 Power to EUT On Off Time [min.]

Power interruption of 2 min. 72 Start of Screening End of Screening +45°C/min. -45°C/min. 72 115 Precipitation

Phase Detection Phase

Steepness depends on UTOL and LTOL UTOL 121212 72

Closed EUT

Open EUT

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LN

2 Exhaust

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Model Typhoon 3.0 Vibration 6 degree of freedom (3 translations and 3 rotations). 10 Hz – 5 kHz 50 GRMSmin. (no load)

Thermal

-100 °C à +200 °C Max. 70 °C/min.

Useful Volume

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VCM 1102 PM 1131 Front LCD Back of the PM: electronics boards

are not covered

Pipe that blows underneath the panel module

2 pipes for the EUT

Both parts are not completely closed

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To increase thermal transition rate

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• No standard known, only guidelines, product dependent

For Barco Defined Products, the specification is the basis.

•

Target UTOL = Spec + 48°C

•

Target LTOL = Spec – 48°C

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•

Low margins indicate poor performance (short life), • High margins indicate good performance (longer life).

Typical Medical Products,

• Target UOL = +45 °C + 48 °C = + 95 °C • Target LOL = 0 °C – 48 °C = - 48 °C • Target VOL = 20 g + 12 g => 35 g

Typical Avionics Products,

• Target UOL = +55 °C + 48 °C = + 103 °C • Target LOL = -25 °C – 48 °C = - 73 °C • Target VOL = 20 g + 12 g => 35 g

Typical Defence Products,

• Target UOL = +63 °C + 48 °C = + 111 °C • Target LOL = -42 °C – 48 °C = - 90 °C • Target VOL = 20 g + 12 g => 35

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Measured level differs a lot from setpoint

Measured Level almost equal to