Analysis and adjustment of temperature curve
First, it must be verified that the total time from the ambient temperature to the peak temperature of the reflux is compatible with the desired residence time of the heating curve. If it is too long, increase the conveyor speed proportionally; if it is too short, the opposite is true. Next, compare and adjust the shape of the graph curve with the desired graph curve to facilitate the selection of the best curve. The left-to-right (process sequence) deviation should be considered when comparing adjustments. For example, if there is a difference between the preheating and reflow zones, first adjust the difference in the preheating zone correctly. Generally, it is best to adjust one parameter at a time and run this curve setting before making further adjustments. This is because a change in a given zone will also affect the results of subsequent zones. We also recommend that novices make relatively small adjustments. Once you gain experience on a particular furnace, you will have a better “feel” to make more drastic adjustments.
The phenomenon shown is that the preheating is too much (upper curve) or insufficient (lower curve). The adjustment measure is to reduce or increase the temperature of the preheating zone. The phenomenon shown is that the active (holding) temperature is too high (upper curve) or too low (lower curve). The adjustment measure is to reduce or increase the temperature of the active zone.
The phenomenon shown in the figure is that the reflux is too much (upper curve) or insufficient (lower curve). The adjustment measures are to reduce or increase the temperature of the reflux zone. The phenomenon is that the cooling is insufficient (the upper curve) or too fast (the lower curve). The adjustment measure is to increase or decrease the speed of the cooling fan. The final graph should match the desired graph as much as possible, and the parameters of the reflow soldering furnace should be recorded or stored for later use. Although this process is slow and laborious at first, through long-term practice, you can eventually gain proficiency and speed, and get high-quality, high-efficiency PCB assembly production results.