Yea, when you get enough co-deposited organics to make a surface finish
pretty, lots of other "strange issues" begin to happen during the soldering
process.

Dave

On Fri, Mar 6, 2015 at 11:01 AM, Stadem, Richard D. <
[log in to unmask]> wrote:

>  That is what I suspected, that it had to be temperature related. Weird
> stuff.
>
>
>
> *From:* David Hillman [mailto:[log in to unmask]]
> *Sent:* Friday, March 06, 2015 10:30 AM
> *To:* TechNet E-Mail Forum; Stadem, Richard D.
> *Subject:* Re: [TN] bright electroplated tin, versus immersion matte tin
>
>
>
> My guess is that those pins are ground pin so they didn't reach the same
> temperatures as the other pins which are probably signal pins. Lower
> temperature means less propensity to volatilize the co-deposited organics.
>
>
>
> Dave
>
>
>
> On Fri, Mar 6, 2015 at 9:41 AM, Stadem, Richard D. <
> [log in to unmask]> wrote:
>
> Just curious. Why did the two pins in the middle of the picture not
> display that condition also? The answer to that question would point to a
> mitigation strategy.
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
> Sent: Friday, March 06, 2015 9:38 AM
> To: [log in to unmask]
> Subject: Re: [TN] bright electroplated tin, versus immersion matte tin
>
> Hi Dave!
>
> Ahh yes, remember a while back when I was working in Tulsa the time I had
> issues with a AMP Densipac connector that I had posted about that you
> answered for me? You were thinking that it was bright tin. Below are the
> photos and the email thread...
>
> Steve
>
> http://stevezeva.homestead.com/files/AMP_Connectors.jpg
>
> http://stevezeva.homestead.com/files/Connector_Blumpies.jpg
>
> ********************************************************
>
> Steve Gregory <[log in to unmask]
> <
> http://listserv.ipc.org/scripts/wa.exe?LOGON=A3%3Dind0906%26L%3DTECHNET%26E%3Dquoted-printable%26P%3D4384754%26B%3D--%26T%3Dtext%252Fplain%3B%2520charset%3Dus-ascii%26header%3D1
> >>
> Sent by: TechNet <[log in to unmask]
> <
> http://listserv.ipc.org/scripts/wa.exe?LOGON=A3%3Dind0906%26L%3DTECHNET%26E%3Dquoted-printable%26P%3D4384754%26B%3D--%26T%3Dtext%252Fplain%3B%2520charset%3Dus-ascii%26header%3D1
> >>
> 06/23/2009 06:49 AM
> Please respond to TechNet E-Mail Forum <[log in to unmask] <
> http://listserv.ipc.org/scripts/wa.exe?LOGON=A3%3Dind0906%26L%3DTECHNET%26E%3Dquoted-printable%26P%3D4384754%26B%3D--%26T%3Dtext%252Fplain%3B%2520charset%3Dus-ascii%26header%3D1
> >>;
>
> Please respond to Steve Gregory <[log in to unmask] <
> http://listserv.ipc.org/scripts/wa.exe?LOGON=A3%3Dind0906%26L%3DTECHNET%26E%3Dquoted-printable%26P%3D4384754%26B%3D--%26T%3Dtext%252Fplain%3B%2520charset%3Dus-ascii%26header%3D1
> >>
>
>
> Subject [TN] "Blumpie" looking connector leads...
>
> Morning all!
>
> Trying to stay cool here! Broke 100 degrees yesterday and Sunday, and it's
> probably going to break 100 degrees today. Summer has come with a
> vengeance! Ran across something yesterday that I've never seen before. We
> build a board that uses this AMP Densipac SMT connector. We've built a lot
> of these boards before without any issues at all. This latest run we have
> something going on with these particular connectors.
>
> Here's a photo of them on the PCB:
> http://stevezeva.homestead.com/files/AMP_Connectors.jpg You can probably
> see that the leads have this "Blumpie" look to them...both bumpy and lumpy.
> This is fresh out of the reflow oven. Here's a closer look:
> http://stevezeva.homestead.com/files/Connector_Blumpies.jpg
>
> If you notice the two pins either side of the white line look fine. They
> are the anchor pins that are for mechanical strength for the
> connector...they are not I/O pins. The rest of the board looks absolutely
> fine too. Not a bit of problem. It's just the I/O pins. We have noticed
> that connectors with certain date codes don't have this problem. Also,
> before reflow the connectors look okay. Luckily we've only built a few
> boards, and we're stopping until we can get to the bottom of this... Have
> any of you ever seen "blumpie" connectors like these before?
>
> Steve
>
> *********************************************************
>
> From: [log in to unmask]
> <
> http://listserv.ipc.org/scripts/wa.exe?LOGON=A3%3Dind0906%26L%3DTECHNET%26E%3Dquoted-printable%26P%3D4384754%26B%3D--%26T%3Dtext%252Fplain%3B%2520charset%3Dus-ascii%26header%3D1
> >
> [mailto:[log in to unmask]
> Sent: Tuesday, June 23, 2009 7:22 AM
> To: TechNet E-Mail Forum; Steve Gregory Cc: [log in to unmask] <
> http://listserv.ipc.org/scripts/wa.exe?LOGON=A3%3Dind0906%26L%3DTECHNET%26E%3Dquoted-printable%26P%3D4384754%26B%3D--%26T%3Dtext%252Fplain%3B%2520charset%3Dus-ascii%26header%3D1
> >
>
> Subject: Re: [TN] "Blumpie" looking connector leads...
>
> Hi Steve - ah, the beauty of being a materials engineer is that the
> industry doesn't seem to learn from past material mistakes so I really
> don't need to learn anything new! I recommend you check with your connector
> vendor to confirm that the connector surface plating is bright acid tin.
> The photos appear to show a bright acid tin surface finish that has
> blistered during the solder reflow process due to excessive co-deposited
> organic material. Bright acid tin finishes (plated correctly) look very
> nice but have terrible solderability characteristics and are a known tin
> whisker generation source. It appears that you may have had a surface
> plating change from what you normally had been procuring. Good luck.
>
> Dave Hillman
> Rockwell Collins
>
>
>
> On Thu, Mar 5, 2015 at 9:01 PM, David Hillman <
> [log in to unmask]> wrote:
>
> > Hi Guy - ok, here is the short list and yes, I have a HUGE dislike for
> > brite acid tin:
> >
> > Brite acid tin (electroplated)
> > 1) grows tin whiskers like a chia pet due to the co-deposited organics
> > in the plating. The same co-deposited organics "boil" during a
> > soldering process causing lots of voids and generally poor solder
> > joints. Very short shelf life - three months is not uncommon. Doug and
> > I have some great pictures of the bubbling in one of our tutorials
> >
> > Matte tin (electroplated)
> > 1) one of the most common component finishes on components today.
> > Lacks thermal excursion robustness but will pass JSTD-002/003
> > solderability testing from good plating processes. Can also tin
> > whisker, less prone than brite acid tin, but also not zero tin
> > whiskers. Good for corrosion issues in some product use environments.
> > Fewer soldering ability issues with stronger fluxes
> >
> > Immersion tin
> > 1) Has poor thermal excursion robustness but will pass JSTD-003
> > solderability testing. Much less propensity to tin whisker when
> > plating formulation includes specific inhibitors. Good for corrosion
> > issues in some product use environments. Very flat and good for SMT
> > assembly. Because it is deposited by a galvanic reaction, typical much
> > thinner than electroplated tin systems. This plating system is covered
> > by the IPC-4554 specification.
> >
> > Take a look in the IPC AJ 820 or the IPC -7095 standards as they both
> > have good sections on surface finishes including some tin plating
> comparisons.
> > And remember, the initiation of tin whiskers is a characteristic of
> > tin itself so all pure tin finishes, regardless of their deposition
> > process, can have tin whisker issues. Hope this helps.
> >
> > Dave Hillman
> > Rockwell Collins
> > [log in to unmask]
> >
> > On Thu, Mar 5, 2015 at 7:51 PM, Guy Ramsey <[log in to unmask]> wrote:
> >
> > > Can anyone give me a nutshell difference between immersion tin for a
> > solder
> > > finish and electroplated tin?
> > > Advantages, disadvantages as a surface finish more than the chemical
> > > and plating process differences.
> > > Thanks,
> > > Guy
> > >
> > >
> > >
> > >
> > >
> > > ____________________________________________________________________
> > > __ 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 and any attachments are only for use by the intended
> recipient(s) and may contain legally privileged, confidential, proprietary
> or otherwise private information. Any unauthorized use, reproduction,
> dissemination, distribution or other disclosure of the contents of this
> e-mail or its attachments is strictly prohibited. If you have received this
> email in error, please notify the sender immediately and delete the
> original.
>
>
> ______________________________________________________________________
> 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] 
______________________________________________________________________