TECHNET Archives

June 2011

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:
"Forrester, Michael (H USA)" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Forrester, Michael (H USA)
Date:
Thu, 16 Jun 2011 10:24:19 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (55 lines)
I have a question about solder balls/splashes on PCBAs.  in IPC-A-610E
section 5.2.7.1 it mentions that solder balls and "fines" that are NOT
encapsulated in flux is a defect.
Section 5.2.7.3 mentions that the inspection for said solder anomalies
shall be done with NO magnification.  We have an SMT assembly that is
manufactured with water soluble flux and has two SMT parts hand soldered
to the board with No-Clean.  In reviewing the rework under
magnification, we discovered solder slivers entrapped in the No-Clean
flux that did not violate the minimal electrical clearance.  So far so
good.  I have several assemblies where there are unmelted solder balls
from the paste and solder slivers (4-5 mils) spread all over the PCB NOT
entrapped in any flux.  I can not see them without magnification, so
does that mean that they pass the IPC-A-610E specification?  In thinking
about this, in theory, once the board is put into service all of the
solder anomalies, not entrapped in flux, could shake loose, converge and
create a short?  So hence my confusion between section 5.2.7.1 and
5.2.7.3.  Any thoughts would be appreciated.  Thank you.
 
Best Regards,
 
Michael Forrester
Sr. Product Engineer
CSMTPE
 
Siemens Healthcare Diagnostics
101 Silvermine Rd.
Brookfield, CT  06804
PH: (203) 740-6452
 

-------------------------------------------------------------------------------
This message and any included attachments are from Siemens Healthcare Diagnostics
and are intended only for the addressee(s). 
The information contained herein may include trade secrets or privileged or 
otherwise confidential information. Unauthorized review, forwarding, printing, 
copying, distributing, or using such information is strictly prohibited and may 
be unlawful. If you received this message in error, or have reason to believe 
you are not authorized to receive it, please promptly delete this message and 
notify the sender by e-mail with a copy to [log in to unmask]

______________________________________________________________________
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
-----------------------------------------------------

ATOM RSS1 RSS2