Matters needing attention of lead-free reflow soldering temperature

         After utilizing flux pollution due to the influence of high temperature oxidation is particularly obvious, lead-free reflow soldering equipment generally help flux management system, to prevent a great number of high temperature, flux of airflow into the cooling zone and condensation in the sink and inside the furnace body, reduce the pollution of the cooling effect and equipment.

         Lead-free reflow soldering system is contains a lot of flux of the high temperature air flow from the preheating zone, before the flow zone and cooling zone, after cooling filter system in vitro, send the clean gas oven, do another advantage is that when using nitrogen protection　　

Lead-free reflow soldering curve set of considerations

　　1, improve the preheating temperature Lead-free reflow soldering, reflow soldering furnace temperature preheating zone to flow than tin/lead alloy the preheating temperature. Usually high around 30 ℃, at 170 ℃ to 190 ℃ (traditional usually in the preheating temperature of 140 ℃ to 160 ℃) to increase the temperature of the preheating zone goal is to reduce the peak temperature to reduce the temperature difference between the components.

        2, extend preheating time Extend preheat preheat time, preheat fast cause thermal shock on the one hand, is not conducive to reduce the formation of peak reflow temperature unlined upper garment, the difference in temperature between components. Therefore, extend preheat preheat time, smooth by welding components temperature rises to a predetermined preheating temperature.

        3, extend the flow zone trapezoidal temperature curve again Increasing flow region trapezoidal temperature curve. In the high reflow temperature control at the same time, increase again flow zone temperature curve width, prolonged peak of small heat capacity of components, the size of the heat capacity components meet the requirements of reflow