Brief Introduction of Reflow Oven Equipment
The reflow soldering oven equipment is the key equipment in the SMT assembly process. The solder joint quality of PCBA soldering depends entirely on the performance of the reflow soldering oven equipment and the setting of the temperature curve.
The reflow soldering equipment has improved requirements for temperature control accuracy, temperature zone temperature uniformity, and transmission speed due to the production process. The three-temperature zone has developed five-zone, six-zone, seven-zone, eight-zone, ten-zone and other welding systems.
Key process parameters of reflow soldering process
1. Welding temperature curve: According to factors such as the external dimensions of the PCB, the number and thickness of the multilayer board, the volume and density of the soldered components, and the area and thickness of the copper layer on the PCB, test the actual welding temperature at the solder joint Set the temperature curve.
2. Control the preheating time, reflow time, and cooling time: according to the length of the heater, control the trajectory of the recirculation curve by controlling the speed of the conveyor belt 4, the cooling zone roll-off gradient is controlled by the cooling time and the cooling zone air volume .
3. As far as possible, the reflow temperature curve overlaps with the reference temperature curve provided by the solder paste supplier.
4. When dealing with SMT reflow soldering on both sides, generally one side of the small-quality component is soldered first, if there are large-quality devices on both sides 7, or when the large-quality device side must be mounted on the process first, the second side should be reflow soldered. The large mass 8 and mass devices that have been soldered at the bottom are protected to prevent the large mass devices from falling off due to secondary reflow.
5. When conducting through-hole reflow soldering, attention should be paid to the displacement of components caused by equipment and transmission system jitter.