Hello,

How big is the connector being replaces?

Can you do a preheat on the board before you put on the solder pot?

The issue may not be a max dwell time, but a variety of factors.  We have
removed and replaced CPU sockets (50mm X 50mm fountain head), which can take
about 15 seconds, give or take and the boards work fine.

The board damage which may occur is not so much the maximum dwell time, but
the high temperature deltas that part of the board goes through with the
solder pot as well as it being localized heat.

Preheat the board if you can.  It will minimize any warpage to the board as
well as any via damage.

David



>From: "Fineline Circuits, Inc" <[log in to unmask]>
>Reply-To: TechNet E-Mail Forum <[log in to unmask]>,              "Fineline
>Circuits, Inc" <[log in to unmask]>
>To: [log in to unmask]
>Subject: [TN] Dwell Time
>Date: Thu, 6 Oct 2005 14:12:55 -0400
>
>TechNetters,
>I have to provide a length of time we can hold a board (FR4) over a solder
>fountain (to remove a Pin Grid Array) before the board gets damaged.
>I need to know what that dwell time is.
>Thanks,
>Sona Sitapara
>Fineline Circuits Inc.
>
>---------------------------------------------------
>Technet Mail List provided as a service by IPC using LISTSERV 1.8e
>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
>-----------------------------------------------------

_________________________________________________________________
Latinos en EE.UU: noticias y artículos de interés para ti
http://latino.msn.com/noticias/latinoseneeuu

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
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
-----------------------------------------------------