SMT Surface Mount Technology

SMT or Surface Mount Technology is an electronic technology used to mount or solder SMD components/SMT devices onto PCB (Printed Circuit Board). This SMT technology is different from other technologies.

The leads of through-hole electronic components are passed through holes in the PCB and then soldered by wave or hand soldering.

But in SMT or surface mount technology, SMD electronic components do not have any leads. They have tiny solderable pins or BGA (Ball Grid Array).

You don't need any previous surface mount experience, as long as you are good at soldering, you can learn to use these parts. There are a few different methods that work well for hobbyists. One can use a desoldering station to solder the board. The method used by the soldering station uses solder paste, which is applied to all pads and contains both solder and paste to hold the part in place. Then put the parts in solder paste and heat the whole part with our pre-prepared desoldering station to solder them.

Another method is to use a regular soldering iron, which is what we'll focus on. There are two slightly different variants of this method, both of which provide excellent results. The first only applies when the PCB (Printed Circuit Board) is done with reflow soldering. (This is where the board already has the PCB manufacturer putting a thin layer of solder on the pads.) In this case you just heat each pin and pad so that the solder on the pad sticks on the leads of the pads. When using this method, you should have a well tinned tip (important for heat transfer), but not have any excess solder. I usually only use it when mounting very fine pitch parts like TQFP devices. If the board doesn't have any extra solder, then you will be able to use conventional soldering.

NOTE: During assembly, make sure the tip of the soldering iron is kept clean. Wipe it with a damp sponge or cloth often and apply a little solder to the tip. This will protect the tip and allow you to solder well. When the solder tends to "ball" or not stick to the tip, the tip needs to be cleaned and re-tinned.