How is the "tin bead" in a fully automatic soldering machine?
When the automatic soldering machine is in operation, the small point of soldering is “tin beads”. How is the “tin bead” in the automatic soldering machine?
Angular Soldering Machine "tin beads" occur when passing through a reflow oven. Our large industry can divide the reflow process into four stages: “preheating, holding, welding and cooling”. The goal of the "preheating section" is to delay the temperature rise of the printed board and the surface mount component to between 120 and 150 degrees, such as to remove the volatile solvent in the solder paste, and to reduce the thermal shock to the component. Therefore, in this process, the inside of the solder paste will have a gasification scene. If the adhesion between the metal powders in the solder paste is less than the force generated by the gasification, a small amount of "solder powder" will flow from the top of the pad. Sometimes tin powder flies out, and in the "welding" stage, this part of the "solder powder" will also melt, forming a solder bead. From this, it can be concluded that the higher the preheating temperature, the faster the preheating speed, the more the gasification scene of the flux will be increased and then collapse or splash, forming a tin bead. Thus, the fully automatic soldering machine can accommodate moderate preheating temperatures and preheating rates to control the composition of the solder beads.