Andrew Russell Morris wrote:
>
> >
> >When using a toaster oven, ensure that the temperature of the oven is less
> >than 80 degs C, before placing the pcb in. Then, turn on the oven, with the
> >temperature of the controller set to, say 209 degs C. When the temp is
> >reached, the controller will switch off the heating element. Open the door
> >and let is cool for a while before removing.
> >
>
> Do you turn the oven off and open the door as soon as 209 degrees is
> reached, or sometime afterward. I know the the controller will switch off
> the heating element at 209 degrees, but it will come back on when the
> temperature drops a little, and keep turning on and off, maintaining
> temperature at the set point until I turn it off.
>
> I don't want to appear stupid. I think you mean as soon as the controller
> switches the heater off for the first time, but I just want to be sure I
> understand what you meant. :-)


To clarify the above, the oven must be below 50 degs C (120 F) before the
heating cycle is started. This is necessary so that the solder paste can
pass through the point needed to drive of solder paste solvents before
the melting point is reached.

The oven should be switch off when the temperature reaches 219 degs C
(426 F) NOT 209 degs C as above, but the fans should continue to run.
Once the set-point is reached the heater must remain off to allow the
cooling cycle to commence.


I hope this is clearer.

Peter.
--
Peter Homann   email: peterh@adacel.com.au       Work : +61 3 9596-2991
Adacel Pty Ltd                                   Fax  : +61 3 9596-2960
250 Bay St, Brighton 3186, VIC, AUSTRALIA      Mobile :     014 025-925
http://www.adacel.com.au     Australian Software Engineering Excellence