With the wide promotion and application of SMT in the electronic industry, the large circulation hot air reflow soldering / microcirculation hot air reflow soldering machine, as the main equipment in the high automation SMT production environment, is more and more favored by people, especially for the large circulation hot air reflow soldering / microcirculation hot air reflow soldering machine, which is commonly used welding equipment, its welding quality is generally concerned at home and abroad.

SMT production line

At present, the reflow soldering equipment can be divided into two types: large circulation hot air reflow soldering and microcirculation hot air reflow soldering. The forced convection mode is adopted in these two types of hot air circulation reflow soldering. When the wind wheel rotates at a high speed, it takes away heat from the electric heating pipe and acts on the PCB board, and the cold air is sucked back from the center of the wind wheel, The process of heat exchange between cold air and hot air is accelerated.

Therefore, the temperature uniformity in the flow region can be ensured. When a large number of boards pass through, the heat taken away by the PCB board can be compensated from the electric heating tube in time. Because PID system is used in the temperature control, it will reduce the temperature overshoot as much as possible and greatly improve the temperature stability. In addition, the main difference between the two modes is that the hot air circulation mode is different (as shown in the figure below)

Heating difference between large circulation hot air reflow soldering and microcirculation hot air reflow soldering

The large circulation hot air reflow welding machine is used to heat one side of PCB, which has a great influence on the deformation of PCB, and the temperature compensation time is relatively long;

Large circulation hot air reflow welding machine

Microcirculation hot air reflow soldering is to heat both sides of PCB, PCB heating is more uniform, the temperature of temperature zone tends to be more stable, greatly improving the welding quality.

Micro circulation hot air reflow welding

Therefore, the hot air circulating reflow soldering machine is the preferred soldering equipment in SMT industry at present. In the past 20 years, guangshengde, a reflow welder manufacturer, has produced a series of products around the hot air circulating reflow soldering, such as six temperature zone, eight temperature zone, ten temperature zone, twelve temperature zone, etc. in terms of transmission mode, there are mesh belt type, chain type, and mesh chain combined type, so as to adapt to manual and automatic placement, Docking with the placement machine to realize automatic on-line production.