Continuing Education (CE) - 24 PDH Credits
Optimizing Electronics Vibration - HALT, HASS, ALT and ESS (Understanding Electronics Vibration)
Whether testing is HALT, HASS, ALT, ESS, Qualification or other type, understanding the product and also understanding how the test affects the product are both key to efficient testing. One step in the HALT process simply states "understand the root cause of failure". This is a fundamental part of all vibration testing but it is often avoided or inadequately covered due to its complexity. This course covers a giant leap in use of technology to visualize vibration damage and understand failure.
(Some previous attendee testimonials).
(Link to Schedule)
A three-day interactive workshop aimed at shortening the
time required for electronics design, vibration testing and (when
weaknesses are found) corrective action. This course applies to
vibration of electronics at system, box or circuit card level.
Methods can also be used in the design and testing of electronic
components to meet vibration standards or desired capabilities.
Discussion of simple methods and animations assist participants
understand the complex responses of their electronics to laboratory
and to field vibration. "Vibration test efficiency" is a new term,
used here to illustrate recent improvements over the past slow
"learning curve" for vibration knowledge. Since vibration life of
most electronics is dependent on response at circuit card level,
methods concentrate on the fatigue damage from PCB modal response.
The purpose of this course is to simplify the complex field of
vibration of electronics and make results understandable.
Tests can determine
fragility limits of test samples. But few tests supply any further
information (beyond pass/fail). Why? Because test measurements can't
fully describe failures. Most tests miss most of the valuable
information that is (with this course) readily available.
In the 70's and 80's,
relatively simple mathematical methods were developed to predict PCB
vibration life capabilities. Why? Because few companies could afford
that era's high-speed computer systems and the technical expertise
needed to analyze vibration. Those early methods, still used by
many, provide guidelines that sometimes work, but they never provide
product understanding. And all too often, such guidelines outright
fail, at great expense - the expense of design and production of an
But since then, the cost of high-speed computer
power has dropped at a rate of about 50% per year. The compounded
cost savings of the mid 80's high-speed computer is over 99.99%. One
of the best-kept secrets of certain large companies is their ability
to produce reliable electronic products at low cost. How? They are
able to fully understand vibration of their electronics through
detailed analysis. Such companies rarely share their reliability
secrets with competitors. But now, with this course, every company
can afford high speed analysis support of its testing.
Let's define test
efficiency as dollar value of information gained divided by dollars
of test cost. If you run a test program without analysis, your
numerator is near zero. Adding modern technology analysis can
immeasurably increase your "information gained" numerator.
Every test performed without detailed posttest
analysis throws information away and wastes money. Rather than throw
it away, capture that information and use it to save many design and
The "design life"
of any system is defined by its weakest part based on the part's
local exposure. Since vibration damage of circuit cards is dominated
by cyclic stresses (caused by modal vibration), analysis should
concentrate on accurately quantifying the stresses experienced by
every component. Design life is limited by accumulated fatigue
damage. Taking advantage of the speed of today's PCs, companies
without prior experience can use this course to understand and avoid
- Initial design product development.
For any vibration requirement, circuit card life is defined by the
failure distributions of a limited number of components. Adding
PoF analysis (defined later, under Background)
to the process helps to identify the weak areas of the design.
Thus PoF analysis is a strong tool for understanding the pros /
cons of proposed design improvements. With virtual qualification,
we analyze various design changes to evaluate the improvements in
previously critical components. We also evaluate the effects on
other regions of the design.
New design and development rules are needed to produce highly reliable products with the weaker and less compliant solder types. Understanding the product at solder joint level helps reach desired reliability goals.
- Damage analysis of test response. When
a component fails in a test, it provides data that represents part
of that component's defined life distribution. By applying PoF
analysis to circuit cards and by incorporating actual test
response, we better understand damage at failure.
- Step stress damage (test response).
Step stress testing is the most efficient method to determine
vibration life capability. Step stress testing becomes more
efficient when it is coupled with PoF analysis and previous
experience. Starting stress levels can be set more efficiently.
Each failure analyzed using PoF adds to future test
- Damage evaluations - multiple vibration
requirements. Every cycle of vibration response contributes
some tiny level of damage to the circuit card. When a design has
multiple vibration requirements, each requirement uses a life
fraction. Some requirements may be insignificant. PoF analysis
allows life fraction evaluation for each requirement. Test costs
can be reduced by eliminating insignificant test portions.
- Damage evaluations - changing response (Q
, Fn). Variations
in assembly procedures for circuit cards can result in differences
in their responses (Q - transmissibility, Fn - natural frequency). Due to the
exponential relationship of life to cyclic stress, response
differences can lead to large variations in life capability. PoF
analysis provides understanding of life effects.
HALT - effective step stress testing - Do's /
ESS - screen effectiveness - unit input
- Component positions
- ESS optimization
- Determining screen effectiveness for
Example applications of PoF vibration
Design of experiments - shaker, fixture, axes
Avoiding blind application of guidelines,
rules, buzz words / phrases
PoF analysis, test comparison
PoF analysis methods throughout the
electronics development process
9am to 5pm
is $2,495. For
registration and payment received one month prior to course, deduct
$100. For three or more
participants from an organization and payment received one
month prior to course, deduct $200 each. Course fee payment is nonrefundable.
Telephone: (763) 559-5166
Individuals - Designers,
developers, producers and vibration test personnel, etc. involved
with electronics printed wiring boards (PWB) subject to vibration.
Participants gain understanding of their products - what fails and
why, also how to repair or redesign to prevent service life
Organizations - Here are a few
- Test labs that desire to supplement their
testing services with understanding of failures.
- Companies seeking to revise their development methods in view of RoHS.
- Test equipment manufacturers that want to
demonstrate the advantages of their equipment.
- Companies using pre-production HALT (highly
accelerated life testing) or post-production ESS (environmental
stress screening) or post-production HASS (highly accelerated
stress screening). All of these employ broad-spectrum random
- Companies having reliability problems -
unexpected service life failures
- Companies that experience field failures that
can't be duplicated in test
- Companies that need virtual evaluation of
design improvements or HALT, ESS and HASS testing or repair
electronic systems, vibration is part of the qualification test
requirements. "Qual" test vibration is intended to accelerate the
vibration damage anticipated during a life of service use. Military,
naval and aerospace companies often must design systems for use in
severe life environments. Today they may be required to use
Commercial-Off-The-Shelf (COTS) boards and components. These may
need "ruggedizing" to withstand a lifetime of military (severe)
As said earlier, random vibration is widely
used. Operating products are exposed to various environmental
conditions (including particularly random vibration) in order to
precipitate (make visible) heretofore latent defects associated with
faulty production parts and poor workmanship flaws. Pre-production
HALT (highly advanced life testing) and post-production HASS (highly
accelerated stress screening) also use random vibration. In all
these situations, the "efficiency" of design, development, testing
and/or screening processes can be increased. This requires full
understanding of how a product responds to vibration. Gaining this
knowledge was once a difficult task. Many specifications and
recommended procedures required a structural expert for proper use
and application. That is no longer true.
A major goal of this course is to prepare design
and test engineers to properly apply tests and screens and thereby
gain needed understanding of their test failures. A secondary goal:
to avoid damaging good products. Excessive damage in fragile areas
can be avoided and yet critical regions can be adequately exposed.
Physics Of Failure (PoF) Analysis
analysis is an evaluation of the product at each point of failure,
considering all contributions to each failure. The course presents
PoF vibration tools which ease the interdependent processes of
design, development and production of reliable electronic hardware.
Both commercial and military companies are incorporating PoF for
developing more reliable products - while reducing costs. Preventing
component level damage under vibration is key to developing products
that meet design requirements. PoF analysis is also key to
optimizing ESS "efficiency".
The PoF analysis taught in this course
translates test measurement data into fatigue damage exposure
indices at point of failure level. All too often, attempts are made
to define hardware capability in response measurement terms, such as
RMS Gs. Statements of survived applied vibration intensity (too
often stated in overly-simple terms such as 6g RMS) are relatively
useless. However, an analysis tool such as PoF adds useful
information to the process. The PoF methods taught here are
efficient AND easy to understand.
The course uses CirVibe, a PoF tool for
analyzing circuit card exposure to vibration, to demonstrate all of
the analysis methods presented. Neither CirVibe nor the course
requires expertise in finite element analysis. Participants receive
understanding that makes their design, development, test and
production of reliable electronics into efficient processes. In its
simplest form. CirVibe models, created in minutes, can provide
valuable information on vibration damage distribution across the any
circuit card under single or multiple environments. A postprocessor
calculates fatigue damage distributions based on component position
on the card. Methods can accommodate steady state and cyclic thermal
contributions to fatigue failure.
©2002 CirVibe Inc. All rights reserved.
CirVibe Inc., Plymouth, MN (763) 559-5166