TECHNET Archives

September 2001

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:
Bill Raymond <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Thu, 6 Sep 2001 09:20:35 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (29 lines)
Jim, thanks I'll start looking into this today!  However, it appears from
testing we are doing that the warp occurs during ramp up - we have heated
some of these chips in an oven to 125 deg C, allowing them to stabilize,
and we measure warp upwards of 6 to 8 mil ... at this point, the solder
balls of the BGA are not even touching the solder paste.

Bill...

At 06:48 AM 09/06/2001 -0600, you wrote:
>Bill,
>If you have not already, look at the cooling rate on your reflow oven.  I
>solved a similar similar warpage problem by reducing the solder cooling rate
>to 1 deg C/second.  I had to modify the blowers in the cool down section to
>achieve that rate.  I found my oven was designed to blast the top of the BGA
>with cold air while the solder was still liquidus.  It provided for high
>speed production, but was warping some of the BGA's.
>
>Jim Kittel

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------

ATOM RSS1 RSS2