Hi Howard - welcome back!  One thing to consider is that smaller ovens 
(aka any oven with less than 7 zones per my definition) will have thermal 
limits in relationship to the printed wiring assemblies. You may have some 
assemblies that due to either the component density or pwb construction 
that demand more thermal energy than a small oven is capable of 
delivering.  Per your description, it sounds like you may have found that 
limit on some designs. As a standard rule of thumb, we always look at 
ovens with a minimum of 9 heating zones due to the thermal demands of the 
assemblies we process.

Dave Hillman
Rockwell Collins
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[TN] IR Reflow Oven capability






Hello all,

Wow, after an 8 year hiatus from the electronics industry, and the 
Technet, I am surprised to see so many familiar names still active on the 
Technet.  I see this as a testament to your wisdom and staying power, 
something I didn't have!

In my new job, in a very small shop of R&D quantity, I see that we have a 
very small IR reflow oven that is seldom used (most of our boards are 
entirely hand soldered or contracted out).  The oven is a ~15 year old 
bench top oven with a heating tunnel that is 3 feet long - 4 heat zones. 
The reports I hear are of  "hit-or-miss" quality output, which might not 
necessarily be the oven and could be the process. Our boards can be 
complex, multi-layer and with some large QFPs, big ground planes, etc.  My 
question is: does anyone have direct experience to share regarding these 
small bench top IR reflow ovens, and did/do you have a positive 
experience?  For the record, the oven is a DIMA SMT Systems SMRO-0252.  We 
use 63/37 solder, RMA flux.  We do profile the boards, but since the 
datapaq has not been calibrated in 10+ years, I look at these profiles 
with some suspicion.  Your feedback will help my decision process to keep 
the oven and work on the process, or work on getting a new oven.  As 
always, I appreciate your insight!

Howard Watson



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