Hi Jack - no, we do not paste our vias or test points. We have not had any 
issues with creep corrosion or any corrosion mechanisms with the 
application of ImAg on both commercial and military products. As George 
detailed, we have carefully selected our flux materials, we clean our 
assemblies after solder processing, and we do use conformal coating. With 
all those caveats, we do have a couple of No Clean applications that are 
very successfully using ImAg too. No surface finish is perfect and there 
are some product use environments which are not appropriate for ImAg but 
it is a good surface finish for many uses.

Dave



Jack Olson <[log in to unmask]> 
Sent by: TechNet <[log in to unmask]>
07/11/2011 09:18 AM
Please respond to
TechNet E-Mail Forum <[log in to unmask]>; Please respond to
Jack Olson <[log in to unmask]>


To
<[log in to unmask]>
cc

Subject
Re: [TN] Leaded or non






I would have said that too, until I started seeing pictures of the 
creeping crud growth on ImAg vias in older assemblies.
(which we use for test points, so they are exposed) How do you get around 
that? Do you paste screen your vias? or conformal coat by default after 
ICT?

Jack

On Thu, 7 Jul 2011 14:26:16 -0500, David D. Hillman 
<[log in to unmask]> wrote:

>Hi Steve - my vote would be the ImAg and lead-free assembly choice. All
>three of your options should work with each having both pluses and
>minuses. My preference is to solder to copper rather than nickel if given
>a choice.
>
>Dave Hillman
>Rockwell Collins
>[log in to unmask]
>
>
>
>Steven Kelly <[log in to unmask]>
>Sent by: TechNet <[log in to unmask]>
>07/07/2011 12:56 PM
>Please respond to
>TechNet E-Mail Forum <[log in to unmask]>; Please respond to
>Steven Kelly <[log in to unmask]>
>
>
>To
><[log in to unmask]>
>cc
>
>Subject
>[TN] Leaded or non
>
>
>
>
>
>
>Hi All,
>I have an 18 layer rigid flex (buried and blind)  that we are preparing 
to
>put the surface finish on and then assemble.
>Lots of BGA's etc.
>The BGA's are lead free.
>Options:
>
>1)      ENIG and lead free assembly
>
>2)      Immersion silver and lead free assembly
>
>3)      HASL and leaded assembly
>Hi end military product.
>
>Thoughts or comments would be appreciated.
>Thanks. Steve Kelly
>
>---------------------------------------------------
>Technet Mail List provided as a service by IPC using LISTSERV 16.0
>To unsubscribe, send a message to [log in to unmask] with following text in
>the BODY (NOT the subject field): SIGNOFF Technet
>To temporarily halt or (re-start) delivery of Technet send e-mail to
>[log in to unmask]: SET Technet NOMAIL or (MAIL)
>To receive ONE mailing per day of all the posts: send e-mail to
>[log in to unmask]: SET Technet Digest
>Search the archives of previous posts at: 
http://listserv.ipc.org/archives
>For additional information, or contact Keach Sasamori at [log in to unmask] 
or
>847-615-7100 ext.2815
>-----------------------------------------------------
>
>
>
>______________________________________________________________________
>This email has been scanned by the MessageLabs Email Security System.
>For more information please contact helpdesk at x2960 or [log in to unmask]
>______________________________________________________________________
>
>---------------------------------------------------
>Technet Mail List provided as a service by IPC using LISTSERV 16.0
>To unsubscribe, send a message to [log in to unmask] with following text in
>the BODY (NOT the subject field): SIGNOFF Technet
>To temporarily halt or (re-start) delivery of Technet send e-mail to 
[log in to unmask]: SET Technet NOMAIL or (MAIL)
>To receive ONE mailing per day of all the posts: send e-mail to 
[log in to unmask]: SET Technet Digest
>Search the archives of previous posts at: 
http://listserv.ipc.org/archives
>For additional information, or contact Keach Sasamori at [log in to unmask] 
or 847-615-7100 ext.2815
>-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 16.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to 
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to 
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
For additional information, or contact Keach Sasamori at [log in to unmask] or 
847-615-7100 ext.2815
-----------------------------------------------------



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

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 16.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------