Required Case History for Reliability Engineers

One for the (Reliability) Books

Guest post by Kirk Gray

The GM Ignition switch failure case history should be required reading for all reliability engineers.

It is rare to have insight into any internal company history of serious electronic and electromechanical failures. Failure analysis and the causes of electronics or electromechanical systems failure can be a difficult investigation for any manufacturing company. Disclosure of the history and data is rarely if ever published due to the potential liability and litigation costs as well as loss of reputation for reliability and safety.

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Eliminating early life failures

Finding and eliminating early life failures

MTBF for electronics life entitlement measurements is a meaningless term. It says nothing about the distribution of failures or the cause of failures and is only valid for a constant failure rate, which almost never occurs in the real world. It is a term that should be eliminated along with reliability predictions of electronics systems with no moving parts. Continue reading “Eliminating early life failures”

Electronics Failure Prediction Methodology does not work

Posted 12-11-2012 by Kirk Gray,

Accelerated Reliability Solutions, L.L.C.

“When the number of factors coming into play in a phenomenological complex is too large, scientific method in most cases fails.  One need only think of the weather, in which case the prediction even for a few days ahead is impossible.” ― Albert Einstein

“Prediction is very difficult, especially about the future.” – Niels Bohr* We have always had a quest to reduce future uncertainties and know what is going to happen to us, how long we will live, and what may impact our lives.  Horoscopes, Tarot

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Why success with HALT begins long before doing HALT

HALT is a BIG change

Implementing a new reliability development paradigm in a company which is using traditional, standards-based testing can be a perilous journey.  It is especially true with introducing HALT (Highly Accelerated Life Test) in which strength against stress, and not quantifying electronics lifetimes is the new metric.  Because of this significant change in test orientation, a critical factor for success begins with educating the company’s top Continue reading “Why success with HALT begins long before doing HALT”

Why HALT is a methodology, not equipment

Kirk Gray, Accelerated Reliability Solutions, L.L.C.

It is easy to understand why the term HALT (Highly Accelerated Life Test) is so tightly couple to the equipment called “HALT chambers” systems.  Many do not think they can do HALT processes without a “HALT Chamber”. Many know that Dr. Gregg Hobbs, who coined the term HALT and also HASS (Highly Accelerated Stress Screens), spent much of his life promoting the techniques and was also the founder of two “HALT/HASS” environmental chamber companies. Continue reading “Why HALT is a methodology, not equipment”

Why Parametric Variation Can Lead to Failures and HALT Can Help

Kirk Gray, Accelerated Reliability Solutions, L.L.C.

Many reliability engineers have discovered HALT will quickly find the weaknesses and reliability risks in electronic and electromechanical systems from the capability of thermal cycling and vibration to create rapid mechanical fatigue in electronic assemblies. Assemblies that have latent defects such as cold solder or cracked solder joints, loose connectors or mechanical fasteners, or component package defects can be brought to a detectable, or patent, condition by which we can observe and potentially improve the robustness of an electronics system. Continue reading “Why Parametric Variation Can Lead to Failures and HALT Can Help”

Reliability Paradigm Shift From Time to Stress Metrics

Kirk Gray, Accelerated Reliability Solutions L.L.C.

Traditional electronics reliability engineering began during the period of infancy in solid state electronic hardware. The first comprehensive guide to Failure Prediction Methodology (FPM) premiered in 1956 with the publication of the RCA release TR-1100:  “Reliability Stress Analysis for Electronic Equipment” presented models for computing rates of component failures.  “RADC Reliability Notebook” emerged later in 1959, followed by the publication of a military handbook know as  that addressed reliability prediction known as Military Handbook  for Continue reading “Reliability Paradigm Shift From Time to Stress Metrics”

What will Advance Reliability Engineering?

Kirk Gray, Accelerated Reliability Solutions, L.L.C.

In all aspects of engineering we only make improvements and innovation in technology by building on previous knowledge. Yet in the field of reliability engineering (and in particular electronics assemblies and systems), sharing the knowledge about field failures of electronics hardware and the true root causes is extremely limited. Without the ability to share data and teach what we know about the real causes of “un-reliability” in the field, it is more easily understood why the belief in the ability able to model and predict the future of electronics life and MTBF continue to dominate the field of electronics reliability Continue reading “What will Advance Reliability Engineering?”

For Maximum Test Value, Take it to the Limit!

When we go to an automobile race such as the Indianapolis 500, watching those cars circle the track can get fairly boring. What is secretly unspoken is that everyone observing the race is watching for a race car to find and sometimes exceed a limit, finding a discontinuity. The limit could be how fast he enters a curve before the acceleration forces exceed the tires coefficient of friction, or how close to the racetrack wall, he can be before he contacts it and spins out of control. Using the race analogy, Continue reading “For Maximum Test Value, Take it to the Limit!”

Why The Drain in the Bathtub Curve Matters

Most reliability engineers are familiar with the life cycle bathtub curve, the shape of the hazard rate or risks of failure of a electronic product over time. A typical electronic’s life cycle bathtub curve is shown in figure 1. Continue reading “Why The Drain in the Bathtub Curve Matters”

No Evidence of Correlation: Field failures and Traditional Reliability Engineering

Historically Reliability Engineering of Electronics has been dominated by the belief that 1) The life or percentage of complex hardware failures that occurs over time can be estimated, predicted, or modeled and 2) Reliability of electronic systems can be calculated or estimated through statistical and probabilistic methods to improve hardware reliability.  The amazing thing about this is that during the many decades that reliability Continue reading “No Evidence of Correlation: Field failures and Traditional Reliability Engineering”