IMHO = In My Humble Opinion
Regards
Mike
-----Original Message-----
From: Leadfree [mailto:[log in to unmask]] On Behalf Of Thomi
Sent: Tuesday, February 10, 2004 8:15 PM
To: [log in to unmask]
Subject: Re: [LF] Antw: technical question: annealing time and
temperature
as we are into english terms:
Werner, and Brian, what does "IMHO" stand for? Something like "It's My
Hottest Opinion"?
Guenter, I am looking forward to repeating Frank Wulff's experiments
where he was looking again on microsections of ATC SJs (Werner I got
that
abbreviation...) after one year and found these GBS steps to a first
impression in correlation with the number of cycles these testboards had
seen (we never published that, however). From his polarised light
microscopy images we always got the impression that the as solidified
microstructure was as you mentioned the lead phase interspersed in a tin
matrix. The tin matrix grain size then did not show markable coarsening,
but of course the lead particles did. The lead phase particle (or
lamellae, from the eutectic
solidification) coarsening was well described by the late Tom Courtney,
who showed this to me during my time at UVa in Charlottesville. The
changes in the solder joint microstructure depend on the second phase
particles, which are in part interspersed within the grain volume, but
also to a very important part along the grain boundaries, where they can
do good - in terms of strengthening, but in solder joints they mostly do
bad - in terms of low eutectic melting - bad effects like grain boundary
embrittlement, and hot cracking before the anticipated melting point,
very well shown by the decrease in "desoldering temperature", explained
by Wolfgang Scheel in Berlin. So I think we should go on to characterise
LF SJs by PLM to show the grain size, and find out if the interdendritic
space is the place where premature failure occurs during ATC, depending
on impurities concentrating on GBs due to the "Zone Refining" process
upon solidification, and use methods like FIB (Focused Ion Beam) to
characterise what happens near the GBs which is too small to check by
standard metallographic techniques (cutting grinding and polishing).
... just some ideas...
Regards
Thomas (looking forward to your remarks, Double Diamond from Mary's
Land)
Thomas Ahrens, Boostedt
----- Original Message -----
From: <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, February 10, 2004 8:02 PM
Subject: Re: [LF] Antw: technical question: annealing time and
temperature
> Hello Guenter,
> I think one English equivalent to your 'swimming against the current"
> is: "going against the grain"
>
> which, by coincidence, would fit in with your discussion on grain
boundaries
> and coarsenning.
> I'll let the native English speakers correct me if I got this wrong.
>
> Jean-Paul
>
> In a message dated 2/10/2004 4:45:25 AM Eastern Standard Time,
> [log in to unmask] writes: I know I am swimming against the
> current (maybe that's wrong in English but at least Werner will
> understand)
>
> _____________________________________
> Jean-Paul Clech
> EPSI Inc.
> Home page URL: http://jpclech.com
> P.O. Box 1522
> Montclair, NJ 07042
> USA
> tel: 973-746-3796
> fax: 973-655-0815
>
> ----------------------------------------------------------------------
> ----
-----Leadfee Mail List provided as a service by IPC using LISTSERV 1.8d
> To unsubscribe, send a message to [log in to unmask] with following text
> in the BODY (NOT the subject field): SIGNOFF Leadfree To temporarily
> stop delivery of Leadree for vacation breaks send: SET
Leadfree NOMAIL
> Search previous postings 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 847-509-9700 ext.5315
> ----------------------------------------------------------------------
> ----
-----
------------------------------------------------------------------------
-------Leadfee Mail List provided as a service by IPC using LISTSERV
1.8d To unsubscribe, send a message to [log in to unmask] with following
text in the BODY (NOT the subject field): SIGNOFF Leadfree To
temporarily stop delivery of Leadree for vacation breaks send: SET
Leadfree NOMAIL Search previous postings 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 847-509-9700
ext.5315
------------------------------------------------------------------------
-------
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
This email, its content and any files transmitted with it are intended solely for the addressee(s) and may be legally privileged and/or confidential. If you are not the intended recipient please delete and contact the sender by return and delete the material from any computer. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited.
Messages sent via this medium may be subject to delays, non-delivery and unauthorized alteration. This email has been prepared using information believed by the author to be reliable and accurate, but Indium Corporation makes no warranty as to accuracy or completeness. In particular, Indium Corporation does not accept responsibility for changes made to this email after it was sent. Any opinions or recommendations expressed herein are solely those of the author. They may be subject to change without notice.
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
-------------------------------------------------------------------------------Leadfee Mail List provided as a service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Leadfree
To temporarily stop delivery of Leadree for vacation breaks send: SET Leadfree NOMAIL
Search previous postings 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 847-509-9700 ext.5315
-------------------------------------------------------------------------------
|
