Werner,

Most of these boards are 0.062" thick, double sided with 4 ounce copper.
There might be some 0.093" thick boards too.  The material is Isola 410
or equivalent.  The problem pin is on IGBTs which are tied to the metal
backing which in turn is mounted on a heat sink.

I'm going to look into experimenting with the temps and other possible
alloys.

Phil

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier
Sent: Wednesday, October 10, 2007 4:44 PM
To: [log in to unmask]
Subject: Re: [TN] RoHS solder and wetting plus thermal reliefs

Hi Phil,
You did not say how thick your PWBs are, but I surmise they are thick.
Removing the thermal reliefs is likely to cause you soldering
problems-they 
are there for a reason. 
For SAC soldering, you need more Cu for the via barrel walls because of
the 
higher Cu dissolution rate of Cu in SAC. "100% barrel fill is desired
with a 
good fillet top and bottom" implies filling with solder; besides poorer
wetting, 
you really need to have the T's high enough-that is likely to cause some

problems with your PWB resin system.

Werner



**************************************
 See what's new at http://www.aol.com

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