SMD Soldering Guide

This guide is meant to help in the soldering of SMD components on PCBs. A single board could be composed of two side, with only one being SMD. This guide is not meant to help in the soldering of boards with SMD components on both sides, as for such processes a soldering oven is needed.

Before Soldering

Solder paste prepping

There are multiple guidelines to use when selecting the proper solder paste, but they are not the focus of these guide.

Once a solder paste is selected it is advisable to keep it refrigerated, as per datasheet recommendation. If using a refrigerated paste, reserve 10 minutes to heat it up uniformly to ambient temperature.

When using a tub to store the paste (and not a syringe) it is advisable to mix the paste for a long time, until it feels fluid again. This is necessary to properly mix the flux with the solder, as it may separate if standing still for too long.

Board and stencil prepping

It is advisable to clean both the board and the stencil with isopropil alchool (>90°).