TECHNET Archives

June 2010

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:
Genny Gibbard <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Genny Gibbard <[log in to unmask]>
Date:
Tue, 1 Jun 2010 09:23:41 -0600
Content-Type:
text/plain
Parts/Attachments:
text/plain (126 lines)
 Thanks for yours and Vladimir's comments.  
These are SAC balls.
We don't have any SEM available.  These are the best magnification we
can come up with right now.  
We have better microscope images that we can see, but the camera is not
on the best microscope.

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman
Sent: May 28, 2010 12:24 PM
To: [log in to unmask]
Subject: Re: [TN] Crystalline solder balls

Hi Genny - yes, these structures have been reported in the industry
before so you are in luck. If these were tin/lead solderballs, you most
likely are looking at copper/tin intermetallic needles structures and if
these are SAC305 solderballs, you are most likely looking at
silver/nickel intermetallic needles. These structures are an indication
that the original reflow solder profile or the rework profile was
temperature/time excessive. Once the intermetallic phases form, they
have melting points much higher than the surrounding solder so  when you
removed the BGA component, they become more visible as the solder joint
volume is removed. 
A second root cause would be incorrect metallurgical composition issues.

Nice photo - the first one is going into my photo gallery. Do you have
any higher magnification shots?

Dave Hillman
Rockwell Collins
[log in to unmask]




Genny Gibbard <[log in to unmask]> Sent by: TechNet
<[log in to unmask]> 05/28/2010 12:52 PM Please respond to TechNet E-Mail
Forum <[log in to unmask]>; Please respond to Genny Gibbard
<[log in to unmask]>


To
[log in to unmask]
cc

Subject
[TN] Crystalline solder balls






http://ipc-technet.groupsite.com/gallery/13595
May not get many responses on a Friday before a long weekend, but your
ideas on what I am seeing is appreciated. 
Sorry the camera on our microscope is not great.
This is some of what remains on a board after a BGA is removed with a
Summit hot air rework station.

> Genny 

______________________________________________________________________
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 15.0
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
Please visit IPC web site
http://www.ipc.org/contentpage.asp?Pageid=4.3.16 
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 15.0
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
Please visit IPC web site
http://www.ipc.org/contentpage.asp?Pageid=4.3.16 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 15.0
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
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------

ATOM RSS1 RSS2