Hey Steven,
Achieving the proper profile like you described does require you to engineer proper conveyor speeds and zone temps. Most conveyorized ovens have the inside of the ovens divided into zones. Each zone has a top and bottom heater that can also be independently controlled as well. The first step is to determine what size over you'll need. The bigger the board, the longer the oven, which also mean more zones. A profiling gizmo is a must as well, to verify what your oven is doing.
I always try to set-up my ovens so that the temps for different product are similar or the same, and vary my conveyor speed to achieve the proper profile (which is dictated from the solder paste manufacturer). It eliminated any downtime that it would take an oven to heat up or cool down between various products.
reply »