I have far too many experiences with hot bar, it still leaves a bad 
     taste in my mouth at times. Some other potential problems:
        1. hot bar warping (depends on shape of hot bar
        2. hot bar sticking to parts
        3. heating rate can be a problem
        4. hot bar material-ceramic seems to work better than metal
        5. Are you going to use no-clean fluxes? If so, seriously consider  
           nitrogen.
        6. Your thermode temp will be much higher than your part temp.      
           Don't be alarmed.
        7. All of the other ideas/concerns are very valid.


______________________________ Reply Separator _________________________________
Subject: HOT BAR SUMMARY
Author:  [log in to unmask] at internet
Date:    6/21/96 2:56 PM


Thank  you for all your responses on this subject!!
     
I summarized the responses and created a small list of vendors and reference 
material  that might be useful to some of you. I am still looking for more 
information on  this subject and would appreciate your comments and 
suggestions. A group reported a 30,000 PPM defect rate with hot bar 
soldering. I wonder if someone can comment on this!!
     
Crtical Factors to consider for Hot bar Application:
 - Cycle Time
 - Temperature Control
 - Loading Mechanism (alignment)
 - Pressure Control
 - Tip Life
 - Programming
     
Potential Vendor
Teka Interconnection Sys.     (401)-781-5730 
Unitek Miyachi           (818)-303-5676. 
Palomar Products         (619)-931-3622 
Todco General Inc.  (619)-549-9229
Pace Miniwave (???)
     
Literature  Reference
"Development in Hot Bar Reflow", by Larry Robert Circuits Assembly, Aug. 
1991
"Fine Pitch Hot bar Reflow with low temp solder and thick PWB", by Donald C 
Burr, Nepcon West 1992
"Hot Bar Lead Attachment Process Optimization for TAB OLB", by Foo- Ming Fu, 
Larry Dodson, IEPS 1991
     
You may also try the following web sites: 
PCMCIA sponsored PC CardLink
     http://www.pc-card.com
     http://www.pc-card.com:80/
AMP's web
     http://www.amp.com/
SanDisk
     http://www.sandisk.com/sd/educate/abc_gen.htm
     
     
Thanks
     
Michael Yuen
[log in to unmask]