Subject: | |
From: | |
Reply To: | |
Date: | Tue, 11 Nov 2008 08:47:29 -0800 |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
My contribution is not an exact answer on your question, but may be of
interest for some people. There are many ways to minimize the amount of
flux and control the atmosphere in which the soldering take parts. One way
that we have introduced recently is to use 'vacuum' VP. Sounds strange, and
it is. This machine pumps out the air in the soldering chamber during the
top temperature stage. So, the solder will wet better into voids and
surface, while at the same time the oxygen level is decreased. It's not a
real vacuum of course, but enough lowered air pressure to have a clear
positive impact on the solder joint quality and also result in less flux
residues. If you are interested, you can read about it below.
http://www.ibl-loettechnik.de/downloads/Aktuelles/Todays%20Vapor%20Phase%20Soldering%20SMTAI%20Orlando%20-%20080820.pdf
Inge
----- Original Message -----
From: "Eric CHRISTISON" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, November 10, 2008 1:47 AM
Subject: [TN] Effect of Soldering in a Ni atmosphere on BGA reliabilty
>A customer has experienced solder joint failures in a lead free BGA device
>which are unexpected for us.
>
> The test the solder joints failed was a shock test in the plane of the PWB
> and the joints failed at the interface between the SJ and our BGA device
> substrate.
>
> We've done similar tests without failure but when we did our trials we
> soldered the devices onto the boards in a hot air oven. Our customer used
> a nitrogen oven. Could this affect SJ strength in any way?
>
> Just wondering whether this is worth investigating.
>
> Regards,
>
>
> --
> Eric Christison Msc
> Mechanical Engineer
> Consumer & Micro group
> Imaging Division
>
> STMicroelectronics (R&D) Ltd
> 33 Pinkhill
> Edinburgh EH12 7BF
> United Kingdom
>
> Tel: +44 (0)131 336 6165
> Fax: + 44 (0)131 336 6001
>
> ---------------------------------------------------
> 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
> -----------------------------------------------------
>
---------------------------------------------------
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
-----------------------------------------------------
|
|
|