Failure Analysis of Electrical and Electronic Products and Components

Failure Analysis of Electrical and
Electronic Products and Components
Cobham Technical Services
Reliability and Failure Analysis
Maintaining reliability
Reliability in electronic systems is important,
whether you are a designer, manufacturer,
distributor or user of equipment. Cobham
Technical Services has many decades of
experience in identifying the causes of
reliability problems from product down to
component level. Cobham Technical Services
provides impartial, expert and fast diagnosis
of problems from design through to use and
failure in the field, working with you to find
a solution.
Where reliability problems arise
There are many situations where having further
information can solve reliability problems and
significantly save time and money. Here are
some typical cases which Cobham Technical
Services regularly investigates:
Thermal and/or mechanical stress
Can cause many types of failure including
internal fractures. The SEM image shows
Ball Grid Array (BGA) connections which have
fractured from thermal fatigue.
Fire
Even when fire has burned away the region
that caused it, identifying the probable cause
is often still possible; sometimes from analysing
a similar non-failed product. It is not always at the
most obvious cause. The image shows a burned
out cable connection.
� Production stoppages threatening costly
delays and losses
� Field returns, where it is essential to
know whether the fault is due to design,
assembly or use
� Conflicting insurance or legal claims
� Assessing new production techniques
� Checking whether components are
counterfeit or below acceptable quality
� Analysing a supply chain to locate the
source of a fault
� Assessing the quality of manufacture
� Determining whether a series of faults
is due to a batch of components or
a change in a process
� Assessing if there should be a product recall.
Failure analysis services
Cobham Technical Services advises across
the electronics manufacturing industry from
aerospace, automotive and rail through to
domestic, IT infrastructure and medical.
Analysis of thousands of cases over more
than 30 years at Cobham Technical Services
has generated an invaluable accumulation
of experience. This capability will help you
understand the root cause of any reliability
problem and help avoid costly repetitions.
Cobham Technical Services offers a range
of services:
� Failure analysis: a practical approach to
failure from whole equipment down to all
active and passive electronic components,
providing you with an analysis of faults,
How products fail
Continuing improvements in the reliability of electronics have led to the expectation that they will never fail. The result is a greater pressure
to correct problems, when they do occur, and to prevent repetition. There are numerous potential reasons why even the best systems or
components can fail, for example:
Poor soldering
Examination of solder joints and wetting will
indicate the quality of the soldering process,
for example on lead-free joints. The image
shows poor wetting of a component lead,
with perhaps insufficient time at temperature.
Electrical overstress
Can cause melting, breakdown, oxidation
and other effects. The image shows a power
transistor with a voltage breakdown.
Contamination and migration
Contamination can be introduced during
manufacture or use. Migration can occur under
electrical stress and is exacerbated by heat and
moisture. The SEM image shows migration of
a metal across an insulating surface.
Mechanical abrasion
Defective surface finish can:
Cause or result from abrasion and wear,
Cause mechanical malfunction or electrical failure,
Cause adhesion of coatings to fail.
Surface analysis can quantify roughness, waviness,
curl and other parameters.