LISTSERV - TECHNET Archives - LISTSERV.IPC.ORG

TECHNET Archives

November 2008

TechNet@IPC.ORG

	LISTSERV Archives
	TECHNET Home
	TECHNET November 2008

	Log In
	Register

	Subscribe or Unsubscribe

	Search Archives

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 >>]

Subject:	query -- solder crack
From:	prashant chopra <[log in to unmask]>
Reply To:	[log in to unmask]
Date:	Wed, 12 Nov 2008 18:56:22 +0530
Content-Type:	text/plain
Parts/Attachments:	text/plain (33 lines)

Hi,
 
 I am working on a project and have an issue with PWB deflection during the FFT testing.  I need your comments and suggestion on the query.
 
We are having FFT test points on the Bottom side of the board. There are 10 points localized in one area and the combined force of all the 10 pogo pins on the PWB is 3KgF.  This PWB is held in position by 2 hooks (near to the FFT test points) and 2 snaps (these are on the other end) in the plastic base.  We observed that there is deflection in the PWB when the pogo pins engage for the test purpose.
 
The issue is that we are having two to three 0603 components which are just about 70mils from these FFT test points on the bottom side. 
And on the top side we have the  two 0603 component which are sitting just on the top of the FFT test points at the bottom side where the pogo pins are getting engaged. 
 
 My concern is with this localized force and the PWB being deflected within the snaps, there could be a strain on the 0603 parts and they may be susceptible to solder cracking.  And the 0603 parts which are exactly on the top have more risk of this solder crack.
 
We also have 0402 parts, but they are more than 300mils away from these FFT test points.
 
What are your thoughts on this?  Can you let me know urgently as we are on critical path for this?
 
Thanks ,in advance to everyone for their valuable feedback .
 
Rgds
Prashant


      Connect with friends all over the world. Get Yahoo! India Messenger at http://in.messenger.yahoo.com/?wm=n/

---------------------------------------------------
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

LISTSERV.IPC.ORG