Anyone can purchase the report and get ALL the data.(Not part of the data.
Not just graphs. But table after table after table and cross section after
cross section after . . . well, you get the idea.) Then they can plot,
graph, analyze to their hearts content and draw their own conclusions.
It is true that the SPVC is an IPC organization composed of solder
manufacturers. But the study encompassed independent consultants who advised
on how to test, independent contractors who volunteered their time to do
analysis, EMS companies who provided their own test vehicles and assembly
lines, government facilities who did the testing and corporations who
provided metalagraphic analysis for the report.
The intent was NOT to do an academic study of how SAC fails. The intent was
(as has been pointed out already) to compare leading alloys and determine if
there REALLY is a difference in either alloy behavior (wetting etc),
assembly performance, metallographic structure and performance under thermal
cycling and thermal shock per accepted JEDEC and IPC test conditions.
I, with the other SPVS participants, stand by the report. In all categories
there simnply is no observable difference in behavior between the alloys
within the limits of the test procedures. Those who doubt are free to take
the data and try and get different conclusions.
If the conclusions of the report are valid then, for general assembly, (not
some niche design that for a reason known only to the designers needs a
specific material) why not choose an alloy that uses less silver and is thus
not only less expensive but requires less mining to support it and performs
identical to the higher silver alloys?
-----Original Message-----
From: David Suraski [mailto:[log in to unmask]]
Sent: Tuesday, August 02, 2005 12:00 PM
To: [log in to unmask]
Subject: Re: [LF] 96.5% Tin / 3.5% Silver vs. SAC305
Dave,
If you don't have full knowledge of this report, why would you call it
biased? Have you read the report? Have you noticed all of the
manufacturability and reliability studies performed by third parties?
Over $1 million and several months were spent on this study.
Why would solder manufacturers be biased against higher-silver alloys
when the costs of these are passed on to end users? The study
objectively tested various tin-silver-copper alloys and found minimal
differences between them. What it comes down to is, why spend more on
silver when it's not needed? If the study found that a higher silver
alloy showed significantly better results, that alloy would have been
recommended.
So... what is your justification for calling it "biased"?
Regards,
David Suraski
AIM
-----Original Message-----
From: Leadfree [mailto:[log in to unmask]] On Behalf Of MA/NY DDave
Sent: Monday, August 01, 2005 10:20 PM
To: [log in to unmask]
Subject: Re: [LF] 96.5% Tin / 3.5% Silver vs. SAC305
Hi Rich, IPC LF Listservers,
I would keep reading beyond this one report.
I would also recommend your own testing for your own conditions and end
uses including reliability. Hopefully you have seen that results on this
LF project have varied depending on researcher/reporter.
It seems to me, without full knowledge, that this is a biased report
based upon the solder producers wanting to standarize with a predominant
solder in the Far East. Less silver is also cheaper.
One question I have been thinking about asking is:
Do we see or know the data on whom on SPVC disagrees or has
precautionary guidance against this recommendation.
Yours in Engineering, Dave
YiEngr, MA/NY DDave
------------------------------------------------------------------------
-------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/(start) delivery of Leadree for vacation breaks send:
SET Leadfree NOMAIL/(MAIL) 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 847-615-7100
ext.2815
------------------------------------------------------------------------
-------
----------------------------------------------------------------------------
---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/(start) delivery of Leadree for vacation breaks send:
SET Leadfree NOMAIL/(MAIL)
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
847-615-7100 ext.2815
----------------------------------------------------------------------------
---
-------------------------------------------------------------------------------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/(start) delivery of Leadree for vacation breaks send: SET Leadfree NOMAIL/(MAIL)
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 847-615-7100 ext.2815
-------------------------------------------------------------------------------
|
