Hi Phil,
Depending on design, the commercially available soldering bars remain 
sufficiently flat up to about 2 inches in length [for more details, see my papers 
Engelmaier, W., “Transverse Joulean Heated Soldering Tool for Mass Terminations,”
 Proc. NEPCON/West, Anaheim, CA, February 1979, pp. 228-235.; and Engelmaier, 
W., “Transverse Joulean Heated Double-Sided Reflow Soldering Machine for Mass 
Terminations,” Proc. NEPCON/West, Anaheim, CA, February 1981, pp. 333-339]. 
Actually more of a concern may be temperature uniformity, which becomes even 
more of a concern with lead-free solders.
One other concern is the amout of solder present—too much and you get shorts, 
too litlle, well...One solution is a soldering bar with a bottom surface that 
is not flat, but rounded, thus giving you solder joints that get thicker away 
from the bar center and thus being able to successfully accommodate a larger 
variation in solder volume.

Werner

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