Difference between single temperature zone reflow soldering and multi temperature zone reflow soldering

Reflow soldering is to realize the mechanical and electrical connection between the pin or solder end of the chip component and the printed board by remelting the solder pre allocated to the solder pad of the printed board. Reflow soldering equipment has two basic structures: one is single temperature zone reflow soldering, and the other is multi temperature zone reflow soldering.

Single temperature zone reflow soldering is to control the temperature change of temperature zone with time according to the reflow soldering temperature curve, and the PCB board is stationary in the furnace. This single temperature zone reflow welding has the advantages of small investment and easy temperature tracking the setting curve. The disadvantage is that the temperature changes periodically, so the production cycle is long and the energy consumption is high. It is generally suitable for single piece or small batch production. For small batch or SMT experiments, single temperature zone reflow welding is sometimes used.

Multi temperature zone reflow soldering divides the soldering furnace into several temperature zones with different temperatures according to the reflow soldering temperature curve, and the PCB board passes through each temperature zone at a uniform speed, so as to realize the processes of preheating, reflow, cooling and so on.

The characteristic of multi temperature zone reflow welding is that each temperature zone is relatively independent constant temperature control, and the control algorithm is relatively simple. Its biggest advantage is high efficiency and suitable for industrial mass continuous production. However, the physical interval of each temperature interval of multi temperature zone reflow welding makes each temperature interval have a certain temperature difference, which will have a certain adverse effect on thermal shock and thermal stress of PCB. Therefore, more temperature zones can be used to reduce this temperature difference.