Reflow oven

A reflow oven capable of working in an inert gas mode and in an air mode, comprising:

• a soldering section, the soldering section being configured to treat a circuit board to be soldered, the soldering section being provided with N soldering sub-zones, the soldering section comprising a heating zone and a cooling zone, the heating zone comprising a plurality of the N soldering sub-zones, and the cooling zone comprising one of the N soldering sub-zones;
• an inlet zone and an outlet zone, the inlet zone and the outlet zone being respectively provided at two ends of the soldering section;
• a first inlet zone isolation duct in communication with an upper side or a lower side of the inlet zone;
• a purification section, the purification section comprising M purification sub-zones, wherein each of the N soldering sub-zones in the heating zone is in communication with a different one of the M purification sub-zones;
• a controllable discharge pipeline and K discharge branch pipes, each of the K discharge branch pipes communicating one of the M purification sub-zones with the controllable discharge pipeline, wherein K is less than or equal to M;
• a valve device configured to, at the inlet of the valve device, connect with an outlet of the controllable discharge pipeline to control open/close of the communication between the controllable discharge pipeline and the external environment, wherein a first end of the first inlet zone isolation duct is in communication with a communication port of the inlet zone, and a second end of the first inlet zone isolation duct is in communication with the one soldering sub-zone of the cooling zone;
• and
• a gas accelerating device configured to supply a gas flow from the one soldering sub-zone of the cooling zone to the inlet zone from the second end of the first inlet zone isolation duct to the first end the first inlet zone isolation duct through the first inlet zone isolation duct.