SMT Reflow Soldering Process

After the board is mounted with all the components, the next critical step is the soldering of those components. Reflow soldering is the most widely used method for attaching Surface Mount Technology (SMT) components to printed circuit boards (PCBs). It ensures strong, reliable solder joints by heating the solder paste to a controlled temperature, allowing it to melt and bond components securely.

Pre-Heating

The PCB enters the reflow oven, where it is gradually heated to activate the flux and remove moisture. There pre-heat parameters are defined as per solder paste supplier recommendations and varies for various type of solder paste used in the electronics manufacturing Industry.

Reflow

• The temperature is raised above the solder’s melting point and this is the phase where the solder joints are made.
• In this phase of the reflow process, the solder liquefies, forming strong electrical and mechanical connections.

Cooling Zone

The PCB is gradually cooled to solidify the solder joints. Controlled cooling prevents sold solder joints or cracking of the solder paste.

Learn More!

Reflow soldering is a critical process in SMT assembly, ensuring high-quality, durable connections for modern electronics. By optimising temperature profiles, using quality materials, and maintaining precise control, manufacturers can achieve efficient and defect-free soldering.

We’ve put together a detailed process guide in a downloadable PDF to help you understand the reflow process in details and manufacture high reliable electronics assemblies. Feel free to download this, share with your teams and execute an effective and efficient cycle count at the end of the year.