Hello Gunter! Exactly the IMC discussions we should be having instead of
"thick" IMC! The BGA ruptures and especially the influence of IMC phases on
soldermask defined small components such as the 0201s and 01005s as you
detailed is clearly an area we need to have better characterized/understood
so we can create DFM rules that result in acceptable product integrity. Add
in the complexity factor of lead-free solder versus tin/lead solder and its
clear the industry has lots of work to accomplish.

Dave

On Fri, May 20, 2016 at 2:10 AM, Grossmann, Günter <
[log in to unmask]> wrote:

> Like David I didn't see any failures that where cause because the IMC was
> thick. I saw ruptures in BGA solder joints in the IMC after vibrations but
> these IMCs where not extremely thick. What interests me at the moment is
> the ongoing miniaturisation. If I look at solder joints of 01005s I see
> that the entire gap between the component and the pad is only IMC. This
> means that our knowledge about low cycle fatigue of the solder joints as a
> failure mode will have to be reviewed since the IMC does not creep but the
> entire stress due to the CTE mismatch is transferred into the PCB and the
> component body and we might observe new failure mechanisms such as
> degradation of the Epoxy, forced rupture of the components etc.
>
>
> Best regards
>
> Günter
>
>
> Diese Mitteilung ist ausschliesslich für die als Empfänger aufgeführte
> Person(en) oder Firma bestimmt. Sie kann persönliche und/oder vertrauliche
> Informationen enthalten. Sollten Sie diese Mitteilung irrtümlicherweise
> erhalten haben, bitten wir Sie, uns umgehend per E-Mail zu informieren,
> sämtliche Ausdrucke zu vernichten und die E-Mail-Dateien zu löschen.
> This message is intended for the exclusive use of the individual(s) or
> entity to whom it is addressed. It may contain information that is
> privileged and/or confidential. Should you have received this message
> erroneously, please notify us immediately by e-mail, destroy any printouts
> and delete all electronic files contained in this message.
>
> > -----Ursprüngliche Nachricht-----
> > Von: TechNet [mailto:[log in to unmask]] Im Auftrag von Zilber Gil
> > Gesendet: Donnerstag, 19. Mai 2016 17:44
> > An: [log in to unmask]
> > Betreff: Re: [TN] Intermetallic and high temperature operation
> >
> > Thank you for your advice.
> >
> > Have a great weekend ,
> >
> > Gil
> >
> > From: David Hillman [mailto:[log in to unmask]]
> > Sent: Thursday, May 19, 2016 6:22 PM
> > To: Zilber Gil
> > Cc: TechNet E-Mail Forum
> > Subject: Re: [TN] Intermetallic and high temperature operation
> >
> > Hi Gil - cool! I hadn't seen this data set so I'll be reading it this
> week. A quick
> > glance thru the investigation shows they were documenting the IMC
> > thicknesses for a variety of solders for different conditions which
> could be
> > very useful to have for future comparison assessments. The next step
> would
> > be to investigate how these IMC thicknesses interact with different
> product
> > use environments. Thank you for the data source!
> >
> > Dave
> >
> > On Thu, May 19, 2016 at 9:54 AM, Zilber Gil
> > <[log in to unmask]<mailto:[log in to unmask]>> wrote:
> > Hi David,
> > Thank you for your prompt response.  The paper I found is:
> > app.aws.org/wj/supplement/<http://app.aws.org/wj/supplement/>WJ_197
> > 2_11_s536.pdf
> > 1.
> > So for the moment I can tell my boss that we can use the board at 100
> deg c
> > for years, unless we will find more data that will warn us.
> >
> > Thank you and best regards,
> >
> > Gil
> > From: David Hillman
> > [mailto:[log in to unmask]<mailto:
> david.hillman@rockwellco
> > llins.com>]
> > Sent: Thursday, May 19, 2016 4:12 PM
> > To: TechNet E-Mail Forum; Zilber Gil
> > Subject: Re: [TN] Intermetallic and high temperature operation
> >
> > Hi Gil - you hit on one of my soapbox topics so I have respond! What data
> > source are you citing that shows 6 micrometers of IMC results in solder
> joint
> > failure? And for the IMC, is it the Cu3Sn or the Cu6SN5 phase? The
> industry is
> > constantly "reminded" that thick IMC is brittle and will cause a loss of
> solder
> > joint integrity but where is the data? Everyone is in consensus that IMC
> > phases have been shown to have brittle properties but when I push for
> hard
> > data/investigations/studies, demonstrating failures due to excessive,
> thick
> > IMC phase, the real root cause has always turned out to be an out of
> control
> > or excessive, abusive soldering process - typically a soldering process
> most
> > folks would  say "ohh, I wouldn't do that with my soldering process".
> For a
> > dwell temperature of 100C, I will grow approximately 5 micrometers of
> IMC (
> > combine Cu3Sn and Cu6Sn5 phases) in 1660 hours using the standard IMC
> > equations for tin over copper (my calculations don't match the details
> you
> > listed). There are multiple examples of electronic products in many
> different
> > product use environments that easily exceed that time and operate at that
> > temperature yet we don't see reports of product integrity data. Unless
> you
> > have some nontypical variable for your product in its use environment
> > (basically, a variation of Doug saying "it depends" but with less gray
> area), I
> > don't believe you have a solder joint integrity concern. Don't get me
> wrong, I
> > think its great that folks are looking at how much IMC phase is
> > produced/found on their solder joints but I think we overstate the topic
> on
> > most occasions.
> >
> > Dave Hillman
> > Rockwell Collins
> > [log in to unmask]<mailto:
> [log in to unmask]
> > m>
> >
> > On Thu, May 19, 2016 at 7:34 AM, Zilber Gil
> > <[log in to unmask]<mailto:[log in to unmask]>> wrote:
> > Hello Technet`s,
> >
> > As we know above 6 micrometers of intermetallic (CuSn) could cause
> failure
> > due to brittle structure of the intermetallic. I found in some
> experiment that
> > at 100 deg C after 32 days the intermetallic (CuSn from Sn-40Pb) grow in
> > about 6 micron. Is it true? What should I do if the board should see 100
> deg C
> > for long time and what about >=90 dig?
> >
> > Thanks,
> >
> > Dr. Gil Zilber
> > Technologiest
> > Elta Systems Ltd.
> >
> > The information contained in this communication is proprietary to Israel
> > Aerospace Industries Ltd. and/or third parties, may contain confidential
> or
> > privileged information, and is intended only for the use of the intended
> > addressee thereof. If you are not the intended addressee, please be aware
> > that any use, disclosure, distribution and/or copying of this
> communication is
> > strictly prohibited. If you receive this communication in error, please
> notify
> > the sender immediately and delete it from your computer.
> >
> >
> > __________________________________________________________
> > ____________
> > This email has been scanned by the Symantec Email Security.cloud service.
> > For more information please contact helpdesk at x2960 or
> > [log in to unmask]<mailto:[log in to unmask]>
> > __________________________________________________________
> > ____________
> >
> >
> >
> > This Email and the attachments were emulated by Check Point
> > ThreatEmulation Service.
> > The information contained in this communication is proprietary to Israel
> > Aerospace Industries Ltd. and/or third parties, may contain confidential
> or
> > privileged information, and is intended only for the use of the intended
> > addressee thereof. If you are not the intended addressee, please be aware
> > that any use, disclosure, distribution and/or copying of this
> communication is
> > strictly prohibited. If you receive this communication in error, please
> notify
> > the sender immediately and delete it from your computer.
> >
> >
> >
> >
> > This Email and the attachments were emulated by Check Point
> > ThreatEmulation Service.
> > The information contained in this communication is proprietary to Israel
> > Aerospace Industries Ltd. and/or third parties, may contain confidential
> or
> > privileged information, and is intended only for the use of the intended
> > addressee thereof. If you are not the intended addressee, please be aware
> > that any use, disclosure, distribution and/or copying of this
> communication is
> > strictly prohibited. If you receive this communication in error, please
> notify
> > the sender immediately and delete it from your computer.
> >
> >
> > __________________________________________________________
> > ____________
> > This email has been scanned by the Symantec Email Security.cloud service.
> > For more information please contact helpdesk at x2960 or
> [log in to unmask]
> > __________________________________________________________
> > ____________
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________