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Date: | Thu, 8 May 2008 12:16:43 EDT |
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Dan,
Being a consultant on a military electronics team, I can say the BGA
performance very much depends on the board layout, component location, method of
locking the board in a card frame, use of board stiffeners, solder used, circuit
board material used (read that Tg 130C or Tg170C epoxy), and a host of other
factors. Vibration analysis is pretty complex and certain consultants have
set up specialties in the subject. Also, I am of the opinion that most
military contractors have developed good design models for vibration environments,
even though they do not publish much on the subject.
One good place to start to understand vibration on board reliability is the
JCAA-JGPP project subjecting over 150 identical boards to a variety of thermal
cycle, vibration, drop shock, and combined environment stresses. The web
site to that report is
_http://acqp2.nasa.gov/projects/LeadFreeSolderTestingForHighReliability_Proj1.
html_
(http://acqp2.nasa.gov/projects/LeadFreeSolderTestingForHighReliability_Proj1.html)
and in particular the vibration section written by Tom Woodrow of Boeing:
_http://acqp2.nasa.gov/LFS%20Reliability/VibEMP%20Rev.%20A%20010906.pdf_
(http://acqp2.nasa.gov/LFS%20Reliability/VibEMP%20Rev.%20A%20010906.pdf)
Please contact me offline if you need the names of some consulting
organizations who can help you in your vibration analyses.
Denny Fritz
SAIC, Inc.
*********************************
In a message dated 5/8/2008 10:06:34 A.M. Eastern Daylight Time,
[log in to unmask] writes:
I have received an inquiry from a customer regarding deflection data. They
want to know if there's any data they can input so they can simulate if their
BGAs will be ejected off their PCBs in a high vibe environment. The PCB is a
14 layer FR-4 .062 thick. Any guidance would be greatly appreciated.
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