Thermal Processing
Industrial heating equipment uses fans or blowers to circulate heated air or nitrogen across a printed circuit assembly to achieve a specific temperature profile. A forced convection oven provides more uniform heating than infrared systems by minimizing the effects of component color or emissivity. This equipment consists of multiple independently controlled zones for preheating, soaking, reflow and cooling.
Airflow Management
Precise control of gas velocity and volume allows for the rapid transfer of heat to high mass components. In a forced convection oven, the air jets are designed to break the stagnant boundary layer on the board surface. High efficiency blowers ensure that the temperature setpoint is maintained even when a heavy load enters a zone.
Nitrogen atmospheres are often used within these systems to prevent oxidation of the solder and the copper pads.
Throughput Capacity
Conveyor speed and zone length determine the volume of boards that the system can process in a single shift. A modern forced convection oven utilizes sophisticated sensors to monitor the environment and adjust the heater outputs in real time. Maintaining a stable profile is vital for the repeatability of the soldering process across different batches of boards.
The length of the cooling zone ensures the solder solidifies before the board exits the machine.
