What has Kirkendall to do with CAF? My knowledge is bit rusty, but from my
analysis of Al to Au heavy wire bonds (long since), I learned that the
'electron wind' caused a asymetric atomic move, which caused vacancies and
spots of material deficiency (always spell this word wrong) which
transchanged homogenic IMC regions into a
sponge-like structure. While CAF is more like an ordinary 'battery' effect.
Someone may well develop this. To search for my old reports makes me
faint...become
a little lazy on old days.
/Inge
If I happen to stumble on any of my findings, I'll send a picture or two for
the wax cabinet of Mr Gregory. Weird things, those kitchenballs..erh..
----- Original Message -----
From: "John Goulet" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, January 23, 2010 5:53 PM
Subject: Re: [TN] TI MSP Early Life Failure?
This is a new subject for me. Here is the abstract I found.
Anyone who has purchased the full report would know what the voltage to
distance ratio would be for this to be a problem. Also the report may need
to be updated to include the result from copper that is pre-stressed as was
discovered in the Pb-free reliability reports, versus the standard copper.
See The Kirkendall effect of the Al-Cu couple with an electric field
by W Liu - 1998 - Related articles - All 4 versions
Kirkendall [1] demonstrated that an imbalance of intrinsic fluxes, the
Kirkendall effect , leads to .... Kirkendall effect is produced as the
copper diffuses ...
www.springerlink.com/index/W50W177225N47X51.pdf - Similar CAF
Characteristics of FR-4 Printed Circuit Board(PCB) for Automotive
Electronics
Document Number: 2009-01-1369
Date Published: April 2009
Author(s):
Jung Gi Han - Hyundai-Kia R&D Center
Won Sik Hong - Korea Electronics Technology Institute
Nochang Park - Korea Electronics Technology Institute
Abstract:
Recently, application of automotive electronics is rapidly on the increase
and consumption of PCB(printed circuit board), which is applied to compose
of electrical circuit, is also rising rapidly in automotive. During the term
of guarantee in automotive, reliability of car electronics must to be
verified and especially research of CAF(conductive anodic filament)
characteristics to have an influence on insulation degradation of PCB is
demanded. CAF is different with electrochemical metallic ion migration. CAF
is generated at the anodic Cu(copper) interlayer and grow in the direction
of cathode Cu interlayer, finally lead to short failure between multiplayer
of automotive electronics. Thus, in this research, CAF characteristics is
quantitatively evaluated and compared with raw materials of FR-4 PCB,
respectively. From these results, failure mechanism and a preventive measure
is showed. Consequently, this research is expected to contribute to improve
the reliability of automotive electronics.
John Goulet
MFG/Process Engineer
----- Original Message -----
From: "Randall L Bock" <[log in to unmask]>
To: [log in to unmask]
Sent: Tuesday, January 19, 2010 11:18:28 AM GMT -05:00 US/Canada Eastern
Subject: Re: [TN] TI MSP Early Life Failure?
Do not have an answer to your question, but Warner was getting worried.
TechNet is alive..
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Chris Mahanna
Sent: Tuesday, January 19, 2010 11:13 AM
To: [log in to unmask]
Subject: [TN] TI MSP Early Life Failure?
Hello Technet,
We are working on a failure analysis of a battery operated remote sensing
device. Failure is linked to 500ohm short power/ground. The assembly
experiences at least (2) 255C reflow thermal excursions. Failure manifests
at ~6 months.
Slicing/dicing isolation yielded: breakdown between two vias (17 mil
spacing) and/or MSP input impedance. Beyond that, original evidence is lost.
We are working the CAF theory, however reproduction of the problem is
proving difficult, possibly due to the low number of opportunities on the
actual board.
For those of you who know that I'm pushing for placement of (the new) CAF
coupons on panels, yes this is our most recent example of the problem.
I would like to get feedback on the possibility that it was the
microcontroller instead...
TI MSP430F1612
Level-3-260C-168 HR
Thanks!
Chris Mahanna
Robisan Laboratory Inc.
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------
|
