Jean-Paul is absolutely correct—if you have a bad design, i.e. inadequate DfR, the solder joints will fail regardless of alloy.
If you want to see a picture of the Danish issue, go to Engelmaier, W., “How to Estimate Solder Joint Reliability, Part 2,” Global SMT & Packaging, Vol. 7, No. 10, October 2007, pp. 64-66 at www.gsmtp.com.
Single-sided PCB solder joints are in my book Class -1 [minus 1]—Gm needed to recall over 4 million SUVs/trucks because of this issue,
Werner
-----Original Message-----
From: Jean-Paul Clech <[log in to unmask]>
To: [log in to unmask]
Sent: Tue, Jan 19, 2010 2:57 pm
Subject: Re: [LF] Fodder for Discussion?
Search for GPU failures and you will find that SnPb solder joints have
failed recently aswell, in areas where SnPb products are still sold (including
North America).
A few years ago (~5-7 years ago), a Danish consumer organization had a
technical report on the internet, showing laptop SnPb solder joint
creep/fatigue failures after < 2-3 years of use. In my practice, over the last
15
years, the most frequent type of failures has been SnPb creep failures in
single-sided through-hole joints. I am sure that Werner can add to the list.
Unfortunately, the parties involved are reluctant to publish.
In many of these cases, SnPb or lead-free, the main issue is a lack of
design-for-reliability (e.g. detrimental effect of stiff leads, large
temperature swings in use, poor choice of materials etc...). These issues will
stay, regardless of solder compositions. No doubt that the problem has been
compounded by the introduction of new (often uncharacterized) alloys.
Best,
Jean-Paul
In a message dated 1/19/2010 2:01:30 P.M. Eastern Standard Time,
[log in to unmask] writes:
You think the Xbox issue is the only one; laptop failures are a real issue
as well.
Quote of the month (not necessarily monthly):
"Quality means doing it right when no one is looking", Henry Ford.
_______________________________________________
Jean-Paul Clech
EPSI Inc. -- There is no short cut to reliability.
P.O. Box 1522, Montclair, NJ 07042, USA
tel. & fax:+1 (973)746-3796
_http://www.jpclech.com_ (http://www.jpclech.com/)
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