TECHNET Archives

June 2013

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
"Whittaker, Dewey (EHCOE)" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Whittaker, Dewey (EHCOE)
Date:
Tue, 18 Jun 2013 19:05:55 +0000
Content-Type:
multipart/mixed
Parts/Attachments:
text/plain (10 kB) multipart/related (10 kB)
It used to be. I got several articles from it. I have not tried it lately. I attached one of the last things I got.
Dewey

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Steven Creswick
Sent: Tuesday, June 18, 2013 12:00 PM
To: [log in to unmask]
Subject: Re: [TN] APEX Papers on Conformal coat and tin whiskers

Dewey

Is this an e-mail link to a group or something?

Steve C

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Whittaker, Dewey (EHCOE)
Sent: Tuesday, June 18, 2013 12:57 PM
To: [log in to unmask]
Subject: Re: [TN] APEX Papers on Conformal coat and tin whiskers

Also try [log in to unmask]
Dewey

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Landman
Sent: Tuesday, June 18, 2013 9:50 AM
To: [log in to unmask]
Subject: Re: [TN] APEX Papers on Conformal coat and tin whiskers

John Barnes is the person collecting the bibliography (> 20,000 citations) 

*  Bibliography for Tin Whiskers, Zinc Whiskers, Cadmium Whiskers, and
  Other Conductive Metal Whiskers  
    http://www.dbicorporation.com/whiskbib.htm

Bob Landman

On Jun 18, 2013, at 5:52 AM, Steven Creswick <[log in to unmask]>
wrote:

> Inge,
> 
> Sorry, but was not me.  I can imagine there being a great deal of 
> non-published work out there, however.
> 
> Smooth skies!
> 
> Steve C
> 
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Inge Hernefjord
> Sent: Tuesday, June 18, 2013 1:27 AM
> To: [log in to unmask]
> Subject: Re: [TN] APEX Papers on Conformal coat and tin whiskers
> 
> FYI
> 
> Someone (Trikeman?) told me that about 10,000 papers exist about whiskers.
> Of course most of them are echoes.
> 
> Inge
> 
> 
> On 12 June 2013 07:26, greg <[log in to unmask]> wrote:
> 
>> There have been several papers published at APEX on the topic. But 
>> whether they address the specific issues raised today I leave to 
>> wiser heads than mine.
>> 
>> APEX 2007:
>> 
>> Effect of Conformal Coating on Tin Whisker Growth, Vijay Kumar and 
>> Linda Woody, Lockheed Martin
>> 
>> Parylene as a Suppressant for Tin Whiskers Growth on Printed Circuit 
>> Boards, Rakesh Kumar Specialty Coating Systems
>> 
>> Whisker Penetration into Conformal Coating, Stephen McKeown, Joseph 
>> Kane, Dr. Stephan Meschter BAE Systems, Johnson City, NY
>> 
>> 
>> APEX 2008:
>> 
>> Effects of Tin Mitigation Processes on Whisker Growth and Solder 
>> Joint Reliability for Chip and Small-Outline Package Components, Tom 
>> Lesniewski and Tom Higley, Northrop Grumman Network Communications, 
>> San Diego, CA 92128
>> 
>> APEX 2010:
>> 
>> Conformal Coatings for Tin Whisker Risk Management, William Fox and 
>> Linda Woody Lockheed Martin Missiles and Fire Control, Ocala, Florida
>> 
>> 
>> And Chris Hunt did publish also but the APEX papers of his do not 
>> talk about conformal coating. (He may have published somewhere else 
>> on whiskers/coatings. Dave who published on tin coated braided wire 
>> may want to weigh in after he returns.)
>> 
>> Having done the file search on the above whiskers/coatings APEX 
>> papers and read their summaries the answer to "Does it help?" seems 
>> (to me) to be somewhere between "yes/no/maybe/it depends." (i.e. it's 
>> "above my pay
>> grade.")
>> 
>> Greg Munie
>> IPC Director of Design Programs
>> 
>> 
>>> -------Original Message-------
>>> From: Mike Fenner <[log in to unmask]>
>>> To: [log in to unmask]
>>> Subject: Re: [TN] minimum thickness of Type UR Conformal coat and 
>>> tin
>> whiskers
>>> Sent: 12 Jun '13 09:07
>>> 
>>> Richard, slightly tongue in cheek I ask: How does soldering with
>> tin/lead
>>> prevent tin finish on PCB whiskering?
>>> 
>>> Phil I recall Chris Hunt of NPL in UK did some work on this. You can 
>>> probably download a copy of paper from their WWW.
>>> 
>>> Best Wishes
>>> 
>>> 
>>> 
>>> Mike
>>> 
>>> 
>>> 
>>> -----Original Message-----
>>> From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D.
>>> Sent: Wednesday, June 12, 2013 2:22 PM
>>> To: [log in to unmask]
>>> Subject: Re: [TN] minimum thickness of Type UR Conformal coat and 
>>> tin  whiskers
>>> 
>>> Not only can the whiskers grow through the conformal coating, they 
>>> can
>> grow
>>> under it like weeds in a stream. NASA has some good pictures of this 
>>> on  their website.
>>> The best tin whisker mitigation scheme is called tin/lead solder.
>>> 
>>> -----Original Message-----
>>> From: TechNet [mailto:[log in to unmask]] On Behalf Of Douglas Pauls
>>> Sent: Wednesday, June 12, 2013 8:10 AM
>>> To: [log in to unmask]
>>> Subject: Re: [TN] minimum thickness of Type UR Conformal coat and 
>>> tin  whiskers
>>> 
>>> Phil,
>>> While this is an answer I "should" know, I don't.  Dave Hillman
>> regularly
>>> attends and presents at the CALCE yearly conference on whiskers and 
>>> so
>> he
>>> keeps up on all of that.  At present, my esteemed colleague is 
>>> bumping
>> his
>>> head on rocks, kayaking upside down, on some white water in North
>> Carolina.
>>> He should be back in the office on Monday and will no doubt answer
> then.
>>> 
>>> From our discussions, the general rule is still "no conformal 
>>> coating  prevents whiskers".  A thicker coating may cause the 
>>> whisker to expend
>> more
>>> energy punching through and yet more energy to punch through an 
>>> adjacent  coating on a lead (usually resulting in buckling), but I 
>>> have yet to
>> hear
>>> about some magic thickness of any kind of coating that completely
>> mitigates
>>> whiskers.  But I could be wrong.
>>> 
>>> Dave?
>>> 
>>> Doug Pauls
>>> 
>>> 
>>> 
>>> From:   Phil Bavaro <[log in to unmask]>
>>> To:     <[log in to unmask]>
>>> Date:   06/11/2013 02:26 PM
>>> Subject:        [TN] minimum thickness of Type UR Conformal coat and
> tin
>>> whiskers
>>> Sent by:        TechNet <[log in to unmask]>
>>> 
>>> 
>>> 
>>> Doug et al,
>>> 
>>> Is there a disagreement in the industry as to what minimum thickness 
>>> of  urethane is required in order to mitigate tin whisker
> concerns?
>>> 
>>> I am hearing that the .003+/-.002" does not provide enough of a minimum
>>> thickness and that the number is as high as .004".   I can understand
>>> wanting the minimum being raised to .002" but higher than that would
>> seem to
>>> make the process much more difficult to control.
>>> 
>>> I have a potential customer asking if we measure the thickness on 
>>> the  individual component leads which is another can of worms it 
>>> seems.  We  always used flat samples to document our thicknesses.
>>> 
>>> I did not get to attend this years APEX so I might have missed the
>> latest
>>> data.
>>> ________________________________
>>> This message and any attachments are solely for the use of the 
>>> addressee  and may contain L-3 proprietary information that may also 
>>> be defined as
>> USG
>>> export controlled technical data. If you are not the intended
>> recipient, any
>>> disclosure, use or distribution of its content is prohibited. 
>>> Please
>> notify
>>> the sender by reply e-mail and immediately delete this message and 
>>> any  attachments.
>>> 
>>> 
>>> ____________________________________________________________________
>>> __  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]
>>> 
>>> ____________________________________________________________________
>>> __
>>> 
>>> 
>>> 
>>> 
>>> ____________________________________________________________________
>>> __  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] 
> ______________________________________________________________________
> 
> 
> ______________________________________________________________________
> 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] ______________________________________________________________________


______________________________________________________________________
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] 
______________________________________________________________________

ATOM RSS1 RSS2