The cooling zone lowers the temperature at a controlled rate between 1 to 4☌ to evenly form solid solder interconnections between components and the board, with ideal grain size and structural strength.Ī common type of reflow oven is the infrared convection oven.The reflow zone heats the assembly to a temperature higher than the solder’s melting point for 30 to 60 seconds to ensure reflow for every soldered lead.This allows fluxes to activate and for the temperature to stabilize throughout all components. The soak zone holds the temperature at a steady level for up to two minutes between 150 to 170☌.The rate of heating in this zone is critical to avoid thermal shock to the components. The preheat zone involves heating the entire assembly at a controlled rate between 1 – 4☌ to temperatures from 100 to 150☌.The four main zones of the thermal profile are preheat, soak/preflow/dryout, reflow, and cooling. The board can then undergo cleaning, testing, packaging, or further assembly into a completed product.Ī typical reflow soldering process follows a temperature profile that characterizes the optimum rate of heating and cooling that the solder paste and components should experience.

The board is then sent through a reflow oven to heat the paste and then cool it, forming a permanent bond between the components and the PCB. A pick and place machine or other placement equipment then positions electronic components onto the PCB, aligning component leads with the solder paste pads. The process begins by laying a stencil with holes cut out for individual pads over a PCB and applying solder paste to the PCB with a screen printer. A typical reflow solder process is carried out as follows. Reflow soldering involves melting a paste of solder and flux to form a permanent bond between electronic components and printed circuit boards. Modern convection reflow ovens feature high thermal transfer efficiency, allowing for shorter profiles and more consistent, even heating compared to earlier models. The invention of the reflow oven solved the problem of excessive time consumption involved in manually soldering electronic components to printed circuit boards. The option to construct homemade reflow ovens reduces costs however, it also limits both functionality and durability. Commercial reflow ovens range in cost from thousands to tens of thousands of dollars. The electronics manufacturing industry maintains SMT as an industry standard due to the advantage it offers of simpler construction of electronic devices. Reflow ovens are electronic heating devices used to mount electronic components to printed circuit boards (PCB) using surface mount technology (SMT).

Vapor phase reflow