Application of HALT at design stage becomes more and more common in electronics industry. Many discussions and disputations of the HALT test interpretation are in full swing. With our HALT test experiences in notebook, desktop and server products, we intend to share and discuss the safety factor of exact product operating limits to its operation specifications in temperature and vibration and common failure modes stimulated thereby. A general perspective of the test setup techniques by product types and its influence is also provided. The distinctive roles of HALT on board level and system level from thermal flow field point of view are also shared in this paper.

1. Understanding HALT
Understanding HALT
Application in Desktop,
Notebook, and Server (了解
HALT在桌面电脑 笔记本电
HALT在桌面电脑、笔记本电
脑、和服务器系统中的运用)
Danny LS Huang, Gerald Chang
©2012 ASQ & Presentation Danny & Gerald
Presented live on Mar 18th, 2012
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3. Understanding HALT Application
in Desktop, NB and Server
了解高加速壽命測試在桌上型電腦; 筆記
型電腦與伺服器上的應用
PRESENTER:
Danny LS Huang - Senior Reliability Engineer
Gerald Chang - Reliability Engineer
Jimmy Yang - Chief, Mfg Tech & Reliability Head
Wistron Corporation
Reno, Nevada Jan 23 – 26 2012

4. Overview
1. What is HALT?
1-1 Design Margin Analysis
1-2 Typical HALT Process
1-3 HALT vs. ALT vs. RDT
2. Comparison of HALT to Typical Reliability Tests
2-1 HALT Margin to Product Spec.
2-2 Different Roles to Play for Board and System Level
2-3 Failure Symptom
2-4 Indices for Early Warning
3. Summary
2012 RAMS – Yang 2

5. 1. What is HALT ?
 HALT: Highly Accelerated Life Test 高加速壽命試驗
1. A reliability technique, one of the design tools.
2. Uncover design flaws by using extreme stresses.
3. Root cause analysis and corrective actions.
In 1980s, Dr. Gregg K. Hobbs started using the term HALT to a new design product.
 Sample Size
Typical at least three to six units.
 The result of HALT is not pass or fail, it’s a design tool for an early
research and development.
 Motivation
1. Design issues discovery.
2. Estimate & improve margin designs.
3. Reduce design time & cost.
4. Determine functional operating/destruct limits.
2012 RAMS – Yang 3

6. 1-1 Design Margin Analysis 設計裕度分析
 Basic concept of product spec and design margin analysis
 Product spec. is defined based on the
customer's needs and the supplier's
capabilities.
 A series of detail defined temperature,
humidity, vibration, shock, or other conditions
will also be defined at the same time.
 By using specific mechanism model, different
types and level of stresses was using to
identify the potential failure.
 The analysis of failure symptoms and stresses
will help to qualify design strength and
manufacturing processes.
2012 RAMS – Yang 4

7. 1-2 Typical HALT Process at Wistron Proto build – Prototype build
EVT – Engineering Validation Test
DVT – Design Validation Test
Reliability in Wistron C Flow PP – Pre Production
MP- Mass Production
Planning Proto build EVT DVT PP MP End of Life
Eng. Pilot Production Mass
Design Lab Pilot Run
Run Pilot Run Production
C0 C1 C2 C3 C4 C5 C6
HALT HALT HASS & HASA
 Testing Methodology (Wistron Corporation)
Temperature step stress  Random vibration step stress  Rapid thermal cycling 
Combined environments.
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8. 1-3 HALT vs. ALT vs. RDT
Highly Accelerated Life Test (HALT)
For product ruggedness design margin (Useful life).
Design issues discovery Root cause analysis Reduce time & cost Product ruggedness investigation
Accelerated Life Test (ALT)
Failure mechanisms identification (Infancy, Useful life, Wearout).
Dominant failure finding Determine product reliability Individual assemblies verification
Reliability Demonstration Test (RDT)
Demonstrating the reliability of a product (Useful life).
Validate run-in time More accurate estimate of reliability Demonstrating MTBF goal
Typical Reliability Tests for DT, NB and Server
DVT HALT
Operation Temperature Test Thermal Step Stress Test
Random Vibration Test Vibration Step Stress Test
Thermal Shock Test Rapid Thermal Transition Test
Power On/Off Test Combined Test (Thermal & Vib.)
Thermal Cycling Test, ESD,
Acoustic & Altitude Test
2012 RAMS – Yang 6

9. 2. Comparison of HALT to Typical Reliability Tests
高加速壽命試驗和一般可靠性試驗比較
2-1 HALT Margin to Product Spec.
 Comparison of thermal margin
NB DT Server Test time
Product Spec 5~40 C 0~45 C 0~50 C
DVT -5~45 C -10~50 C -10~55 C >7 Days
HALT -60~100 C -60~100 C -60~120 C 2~4 Days
 Random Vibration Comparison
NB DT Server
DVT 2~250Hz 5~500Hz 5~500Hz
HALT 10~10K Hz; 50Grms (6 DOF)
 Combined Stress
NB DT Server
DVT x x x
HALT -60~100 C +10~10K Hz; step stress to 50Grms
(Combined Stress) (6 DOF)
2012 RAMS – Yang 7

10. Qualmark Typhoon 4.0
QualMark Typhoon 4.0
Temp range: -100~200C
Vibration range: >50Grms
Random: 10~10kHz
Temp ramp rate: 60C/min maximum
Test table: 122 x 122 cm
2012 RAMS – Yang 8

11. 2-2 Different Roles to Play for Board and System Level
 System Level
 Verify the rated characteristics of materials .
 Evaluate the designed thermal and mechanical structure (inner flow field and
damping).
 Board Level
 Validate the material selection and fabricating process.
Ducting pipes Fixture
The set-up of ducting pipe could
follow the design of flow field.
The UOL was improved from 40C to 70C by Focus on the shape of UUT and using
removing the initial failure symptom. different fixture to set up.
2012 RAMS – Yang 9

12. 2-3 Failure Symptom 失效現象 1/5
 System shutdown
Reaching the self-protect gating temperature point on either system itself or
semiconductor devices.
Automatic shutdown Unable boot System crashed Auto-reboot
 System frozen
Unstable performance of devices or wrong component specification, especially
component quality level, selected.
No display Hung up Blue/White Screen Device failure
Picture Demo
2012 RAMS – Yang 10

13. Note Book 2/5
Top symptoms are Unable boot, Auto-shutdown and Hung up respectively in
different stresses level.
2012 RAMS – Yang 11

14. Desktop 3/5
Top three symptoms are also Unable boot, Auto-shutdown and Hung up
respectively in various stresses.
2012 RAMS – Yang 12

15. Server 4/5
Top symptoms are Unable boot, Auto-shutdown and Hung up respectively in
different stresses.
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16.  Photos of typical failure symptoms of NB 5/5
Blue screen White screen LCD paneal no display USB device failure
 Photos of typical failure symptoms of DT  Photos of typical failure symptoms of Server
Screen abnormal Parts damaged System stuck in DOS Screen abnormal
2012 RAMS – Yang 14

17. 2-4 Indices for Early
 Mode of design margin
The current product design margin and different limits as LOL, UOL and VOL are
listed as below table.
Mode of design margin
 Minimum design margin
Products failing to meet this index can be inferred to have high risk in reliability or
poor performance.
Minimum design margin
2012 RAMS – Yang 15

18. 3. Summary
 By sharing our own database, the average performance of NB, DT and
server products were showed and understood.
 HALT helps designers to find out design margin and confirm the
weaknesses for improvement.
 With the indices, we are able to compare the design margin of new products
to its product families.
 Through learning and sharing test results, we provide empirical experience
on various products with HALT technique!
2012 RAMS – Yang 16

19. Questions
Thank you for your attention.
2012 RAMS – Yang 17