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Subject:
From:
Richard Haynes <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Tue, 8 Jan 1980 17:20:17 -0500
Content-Type:
text/plain
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Hi,
I presented a paper at the EOS/ESD99 National Tech Meeting in Fla and a
tutorial97. Enclosed is the title and abstract. If you need more feel free
to contact me offline or if you think there is sufficient interest I will
provide the sections of interest to our group.
Thanks
Richard

   Development of Accelerated Aging Test for ESD/EMI Protective Materials
and Electrical Discontinuity at Seams
   and Interconnections

    Richard Haynes
   Richard Haynes Consultants
    609-497-4584
         [log in to unmask]

Abstract
Many studies of new protective ESD/EMI materials, such as antistats, and
conductive members of a seam or interconnection, such as metals that make up
corrodible seams and interconnections, should be regarded as incomplete.
Little or no attention has been paid to changes in essential material
properties exposed to various environments because the test takes too much
time. A procedure for development of accelerated tests is described. There
are a number of variables that can be used to reduce the time usually
required for accelerated aging tests. These variables include but not
limited to: temperature, percent relative humidity, mechanical and
electrical properties. Examples from the literature are cited to show how
temperature can be used to develop acceleration factors to reduce the time
for aging in outgassing and resistivity aging. Corrosion reactions can
degrade the ESD/EMI protected product by promoting electromagnetic emissions
and also producing electrical discontinuity at seams(EDS) and
interconnections(EDI). These EDS can result in secondary ESD events. EDI's
can result in malfunctioning of circuits. Under these conditions temperature
can be used to produce large acceleration factors thus reducing the time to
simulate the lifetime aging process of the electronic product.



================================================================
-----Original Message-----
From: David Douthit <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Thursday, January 13, 2000 1:02 AM
Subject: Re: [TN] ESD/Latchup and Corrosion?


>Paul,
>
>Thank you for the reply. I am a little confused when you wrote about
>dissimual metals corrosion. I believe the concern here is atmospheric
>degradation due to contaminates
>( gases, liquid acids, and ionic submicron particles ) plus oxidation
>will build a non-
>conductive layer on the surface. I don't believe electrolosis is even a
>minor factor in this process. ( But what do I know!)
>
>It is fairly common for flght crews on commerial airlines to "reset"
>circuit breakers when systems "freeze". Most of the hardware is forced
>air cooled internally using dry (<5% RH) unfiltered ( very dusty) air.
>
>There have also been cases where multiple systems have "lockup" creating
>some very
>interesting times for the pilots. ( The cause for many of these
>multi-systems failures
>have never been found using standard and special tests)
>
>I have personally been involved in several of these investigations and
>it was very frustrating. This failure mode is the first one I have found
>which provides a reasonable
>explanation of what happened. The problem is what does one do about it.
>
>You are quite right about no one wanting to talk about CMOS Latchup.
>Sort of an industry secret I guess. I tried asking several vendors about
>Latchup voltage levels
>for their products and was politely ignored. ( Go away and don't bother
>me)
>Oh well!
>
>D. A. Douthit
>
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