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Subject:
From:
Richard Haynes <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Tue, 8 Jan 1980 17:33:20 -0500
Content-Type:
text/plain
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text/plain (284 lines)
Hi all,
I presented a paper at the EOS/ESD99 on this issue. I have enclosed an
abstract.
Thanks
Richard Haynes

========================
   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: Paul Klasek <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Wednesday, January 12, 2000 8:27 PM
Subject: Re: [TN] ESD/Latchup and Corrosion?


>Electrolosis (yep, NOT to be confused with Electrolysis [sweetheart's
>domain]);
>even the dumb spell checker (apart from search engines and hair [what
hair?]
>saloons budding proprietors) goes for it.
>
>Soo (you asked for it) :
>
>The Electrolosis has been know to Prague's alchemists since middle ages .
>In more recent times it hit cement educated architects on critical
Aluminium
>to SSteel mounts (high tensile fun);
>few decades ago, with some spectacular structural failures on few classy
>projects .
>
>This scaled down is much less spectacular ; however still known that bad
>contact alloy (good coin silver ok)selection on OAK switches i used to
>compose (couple decades ago) for local navy (subs) could cause serious
>distress in deep end .
>
>The brief you listed does display jumbled knowledge of the subject ;
>the mix of Electrostatic and Electrolosis terms is incoherent :
>Electrostatic damage is acknowledly understood as a flash with however
>delayed effects;
>Electrolosis is very much in chemical side of metallurgy from true (live =
>powered) view of subject .
>Some may argue it's same , not to me (sorry), the currents are else than
>static .
>
>Otherwise the observation is very much valid and lucent's deep interest in
>switching reliability is obvious .
>The comments interest is practical or academic ?
>(If you have specifically touchy (literally) subject ; let us know, Net is
>indeed good fish tank)
>
>Both are lengthy and not enough papers is published as this is usually one
>of the hash proprietary items,
>as the research mostly rises from pressing needs ; with little benefits
from
>public view,
>on tech site often even overzealous "need to know" base (alloys).
>(pathetic to the point even latrine DWG's in sensitive places are
classified
>!)
>
>Personally (holding BL veterans in deep esteem) 'm surprised it breaks as
>news in 99.
>Would blame wheel reinventions due to ever rolling takeovers and
>restructures .
>Archives are great source of high tech evolution .
>
>http://www.amug.org ; nice site
>have a fun Dave                                 pk
>
>ps
>
>What's cool in Arizona ? (know only cacti family, few still in old Sydney
>suburbs from 60's psychedelic trends)
>
>
>-----Original Message-----
>From: David Douthit [mailto:[log in to unmask]]
>Sent: Thursday, 13 January 2000 10:28
>To: [log in to unmask]
>Subject: [TN] ESD/Latchup and Corrosion?
>
>
>Technetters,
>
>I am interested in any comments about the following abstract of a report
>presented
>Oct. '99 at the Electrochemical Society meeting in Honolulu by Bell
>Labs.
>
>D. A. Douthit
>
>--------------------
>
>Corrosion Induced Electrostatic Damage Potential
>
>John P. Franey
>Lucent Technologies Bell Labs
>
>Room 1B301
>600 Mountain Ave.
>Murray Hill, NJ 07974
>
>Historically, the corrosion of electronic materials has been concerned
>with
>the aspects of solderability, loss of low resistance surfaces, and
>galvanic
>corrosion of plated /layered metal structures. This paper describes a
>degradation of electronic functionality that takes place prior to the
>traditional corrosion initialization levels. Electrostatic damage (ESD)
>occurs when a static charge, which is generated on a material raises
>it's
>potential high enough to breach the insulation resistance of a nearby
>grounded conductor. These conductors can be for example, connected to an
>
>input line on a sensitive integrated circuit, or a more robust print or
>feed
>through on a circuit board. The potentials can range from 20 to 30,000
>volts.
>
>The component damage occurs when the discharge of this charged material
>creates a current flow (in amperes of electrons) through a conductor
>interface to ground. The energy of this discharge can cause complete or
>partial evaporation of a conductor. When the complete evaporation of a
>pathway occurs a failure is noted in initial testing. If the evaporation
>
>of an electron path is partial the component may pass testing and be
>incorporated in apparatus. Failure may occur prematurely at a future
>date.
>
>The measure of energy dissipated in a path is calculated by the formula
>I 2
>R (where I is electron current flow density in Amperes and R is
>resistance
>of the pathway in Ohms) the predominant factor in total energy (heat)
>dissipated by the pathway is the current density. A corrosion product on
>a
>conductors surface elevates the Electro Static damage potential in two
>distinct modes.
>
>Increasing the surface resistance of a metal increases the surface
>insulation capacity. Corrosion products interrupt the low resistance
>skin of
>the metallic conductor. The surface resistance of a metal approaches or
>is
>equal to the bulk resistance of that material. As corrosion products
>form on
>the surface of this metal the surface resistance increases. Typically
>the
>measurement to indicate a corrosion process has initiated are in the
>range
>of micro ohms. Some advanced techniques indicate pico ohms. However,
>prior
>to the increase in surface resistance an increase in insulation capacity
>
>takes place. Taking copper as an example. Copper oxide and copper
>sulfide
>have dielectric constant s many times that of air. As a charged object
>increases
>it's potential an arc will occur through a grounded part of the
>sensitive
>circuit. As the corrosion product increases so does the insulation
>capacity
>of the metal surface, and the arc over potential. If a discharge occurs
>at a
>lower potential less damage is done. A corroded surface arcs at a higher
>
>potential, the potential for damage increases with corrosion product.
>
>Another aspect of Ohms law shows that w=E/I where E is the arc
>potential.
>Given that watts dissipated is the square of I as E increases with R the
>
>damage increases by the square of I. This formula indicates that if the
>corrosion growth is linear the damage will follow an exponential curve.
>
>The second mode of failure is from a discontinuous surface skin.
>Electrostatic damage radiates a signature wave in the range of 1 to 2
>gigahertz. These microwaves of energy travel on the surface of
>conductors due to the skin effect of AC waves. Corrosion products
>disrupt these waves from
>traveling to ground . When this occurs the disruption site will
>retransmit
>the energy on a different plain and will cause spurious noise emissions.
>
>These emissions cause functional failures of digital electronic systems.
>
>Lock ups are common and difficult to find because of the transient
>nature
>of the discharge phenomena.
>
>Corrosion products can amplify the ESD noise problem by changing the
>impedance of a properly ESD protected circuit. In many cases
>electrostatic
>damage will change the impedance (Q) of a circuit. This detuning may
>force
>an ESD generated wave to take a different path to ground than originally
>
>engineered. This aberration in performance can be directly attributed to
>
>corrosion.
>
>In summary: As electronic components use less material, become more
>sensitive to voltage and current variations, and increase their
>operational
>speed, corrosion can take on a myriad of new consequences. These new
>phenomena can be caused by fractions of what have in the noise type
>measurements in the past.
>
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