Beginners guide to soldering

SMD components are extremely small that they can't be gripped with hands. Tiny SMD components are soldered or unsoldered with an hot gun or IRDA rework station, but bigger ones are soldered with a soldering iron. In this tutorials we shall learn how to solder or unsolder SMD components both with rework stations and soldering iron.

Instruments for soldering SMDs

SMDs are soldered with either Soldering iron or rework stations, rework stations are of two types; standard filament type (hot gun) and infrared rework station (IRDA). So we'ii learn how to use the three types in this tutorial.

How to solder with a Soldering iron.

You might not be able to purchase other instruments for soldering, but using a Soldering iron is cheap to get started.  A soldering iron contains an heating element, it generates much heat when plugged to mains sockets(AC). Soldering irons are of two types, Temperature controlled and the direct type, the temperature controlled type has a controllable temperature, it consists of a rotatary knob for viaring it to a desired temperature, some have a password switch.  The direct type temperatures can't be changed, it is directly connected to the mains.  It is important to know the types of Soldering irons tips and their functions to avoid damage to electronic components. There are two types of tips applied in different conditions.

Conical tip.

Usually in a conical shape. It is use for soldering extremely tiny components. It has the ability to deliver heat to a component while soldering  without affecting it surroundings.

Chisel tip

It usually in form of a chisel, it has a broad tip, it is use for soldering big components.

Conventional sponge.

It is use for cleaning soldering iron tips from oxidation which can reduce soldering experience, using a soldering device without cleaning will leave it black or rusted after soldering. Most technicians and engineers use wet sponge for cleaning but this reduces its lifespan due to contractions and expansion, to avoid this it is advised to use a brass sponge.

Soldering stand.

When soldering, our soldering device do get hot to about 200F, this can cause fire or burns to both the user and materials around it. It is advisable to place it in a soldering stand when not in used. Most soldering irons bought on Amazon and inline stores have soldering stands with them.

PCB holder.

It is use for griping boards while soldering. Some consists of a microscope for viewing SMDs while soldering.

Solder lead.

It is a fusable alloy of copper and tin which melts when heated. It is use for soldering joints and connections. They're of different sizes, thick ones are use for soldering big components while thin ones are use on SMDs. Please avoid using Lead that contains lead because it is poisonous to your health when in use.

Nose mask and spectacles.

When soldering it is important to consisder your health. During Soldering, solder leads produces smokes, when inhaled it poses a serious risk to your respiratory system and your eyes. It is necessary to get a nose mask and spectacles. You can use a carbon filter mask if you can purchase one, it consists of a fan for drawing air over animal charcoal for filtration.

Proper soldering steps.

 1. Apply tinner or clean  the tip of the soldering iron to disolve oxide of iron for better soldering.

2. Apply rosin flux to the soldering pad.

3.Add solder lead to the pad.

4.Mount the SMD on the solder lead with a tweezer.

5.Grip the tweezer in place and apply fused solder to the SMD terminals and wait for it to set. 

How to unsolder SMDs with soldering iron. 

1. Add rosin to the terminals. 

2. Heat the ends with soldering iron 

3.grip the SMD firmly and lift gently when the lead melts completely.

If you successful did it congratulations!! practice more and more to become a professional.

How to solder with Hot gun.

Another way to solder SMDs is by using an hot gun. It is more convenient and efficient than using a soldering iron.  Hot guns have changeable mouth ends for controlling the way hot air flows out, avoid using big ones for soldering SMDs because it can damage other components around it. Hot guns uses elements that generates heat when plugged to AC mains. It consists of a fan for blowing heat from the filament. It also have a knob for controlling the filament temperature and the air flow. It can be use for just blowing away dust on PCBs because it temperature can be reduced. When soldering always heat with care, don't apply to much heat to components that contains plastic to avoid melting, you are advised to check the the temperature rating of the material on google or on it spread sheet data if you gat one for the one you are soldering to avoid spoiling it.

Steps in soldering SMDs with an hot gun.

1.circuit pad to avoid dust. 

2. Apply rosin flux to the terminal pads for better soldering. 

3.Melt solder lead on the pads with a soldering iron. 

4.Place the SMD on the pads and grip firmly with a tweezer to avoid blowing away by the hot air when heating. 

5.Apply hot air to the pads until the leads becomes shinny. 

6.Allow to set completely before removing the tweezer. 

How to unsolder SMDs with hot gun.

1. Apply rosin flux to the pads of the SMD
2. Apply heat to the pads with a hot gun. 
3. Grab the SMD with a tweezer and heat its terminals gently until the lead melts completely.

Lift the SMD gently to avoid pulling off the PCB shits. Now if you have done it successfully, practice as much as you can to become a professional on less useful electronics boards.