We have spent a lot of time developing models to predict the temperature
profiles within an assembly during reflow. If we know the properties of
the constituents (esp SHC of the PCB laminate and larger components) we
can very accurately predict the temperatures and thus time above reflow,
ramp rates etc. This lets you do profiling expts. within the computer or
look at e.g. the effect of moving components, changing properties etc.

There is some more background to this on our web pages:

http://info.lboro.ac.uk/departments/en/RESEARCH/MP/ig-index.html

and you can look at some pretty pictures at my "other home page" at
the NIST Centre for Theoretical and Computational Materials Science:

http://www.ctcms.nist.gov/~whalley/

(you can see lots of other interesting stuff on the NIST solder joint
modelling pages at  http://jeeves.nist.gov/ )

David Whalley
Loughborough University


>We are investigating the feasibility of a software tool to predict 
>the reflow soldering profile. As input we want amount and type of 
>components, print parameters (thickness, layers, area etc.). As output:
>conveyor speed, the different temperatures and convection % for our
>hot air reflow machine.
>
>Does anybody know tools that can accomplish this? If not, are you 
>interested in the results or do you just want that bright and shiny 
>solder joints (target condition class 3)?