Influence of equipment characteristics of reflux furnace on temperature curve

Reflow soldering temperature curve is realized in reflow soldering equipment, so reflow soldering temperature curve will be affected by the characteristics of reflow soldering. Different reflow soldering furnaces have different number and length of heating zone, different air flow and different furnace temperature capacity, which will affect the reflow soldering temperature curve.

1、 Influence of heating zone number of reflow soldering equipment on temperature curve

For reflow soldering furnaces with many heating zones (8 heating zones), since each furnace zone can set the furnace temperature separately, it is easier to adjust the reflow temperature curve. It can also be done for the reflow temperature curve with complex requirements. However, small reflow soldering equipment (less temperature zone), because it has only four adjustable temperature zones, it is difficult to obtain complex curves, but for SMT welding without special requirements, small reflow soldering equipment can also meet the requirements, and the price is cheap. On the other hand, the advantage of large reflow equipment is that the belt speed of conveyor belt can be at least twice as high as that of small reflow equipment, so that the output of large reflow equipment can be at least twice as high as that of small reflow equipment. This is crucial when mass production lines pursue capacity.

2、 Influence of hot air flow of reflow soldering equipment on temperature curve

At present, most reflow soldering equipment is mainly driven by fan forced hot air circulation, so the fan speed determines the air volume. Under the same belt speed and the same temperature setting, the higher the speed of the fan, the higher the temperature of the reflux curve. When the fan motor fails, if it stops running, even if the furnace temperature display is normal, the reflow soldering temperature curve measurement will be much lower than the normal curve. If the failed motor is in the reflow area, the PCB board is prone to cold soldering. If the failed motor is in the cooling area, the cooling effect of the PCB board will be reduced. Therefore, the motor speed is a programmable reflow soldering equipment, and the fan speed is also one of the parameters that need to be checked frequently.

3、 Influence of furnace temperature capacity of reflow soldering equipment on temperature curve

Reflow soldering sometimes occurs. When welding a small PCB board, the welding result is very good, while when welding a large PCB board, the furnace temperature in some temperature zones will drop slightly. This is because the large plate absorbs more heat and the heat capacity of the furnace is insufficient. Generally, it can be adjusted by increasing the fan speed. However, the capacity of furnace temperature is mainly determined by the design factors such as furnace structure and heater power, so it has been fixed in the design of reflow equipment manufacturers. Users must consider this factor when selecting reflow equipment. The larger the heat capacity, the better. Of course, the more power the furnace consumes.