Figure A: Sample Materials

Soldering is the process of liquidating lead solder in order to create a mechanical and conductive fixture between the board and an electrical component. This allows for the component to be secured to what it needs to be connected to and be able to conduct electricity.

Materials:

Soldering Iron
Sponge
Goggles
Face Mask with Filter
Heat Resistant Gloves
Lead Solder
Component (Resistor for Example)
Solder Board or Circuit Board or Prototype Board or PCB
Wire Strippers
Solder Braid (Optional)

WARNING:

The soldering iron can be temperatures over 600F (or 315 C). This means the soldering iron, electrical component, and circuit board can burn you while soldering. Lead solder when melted also releases toxic fumes.

Safety Tips:

Wear goggles, heat resistant gloves, and a face mask at all times
Don’t touch the tip of the soldering iron, the electrical component, nor the solder board while soldering

Step 1: Setup

Figure B: Soldering Iron Setup

Place the soldering iron on the the same side as your dominant hand
Plug in the soldering iron
- WARNING: Do not touch the iron tip anymore
Dampen the sponge so that it is moist to the touch
Take the roll of solder and cut off a 6 inch strip with the wire strippers
Place the strip of solder, electrical component (resistor), and circuit board in front of you

Step 2: Preparing the Component

Figure C: Bending the Component

Pick up the component and hold it where you want it to go on the circuit board
Bend the legs of the component at 90 degrees in the same direction
- The location of the bend is where the holes overlap the metal leads of the component
Place the legs of the component in the holes on the board and splay out the legs as shown in Figure C
Turn over the circuit board
- The resistor should be facing towards the table/ground and the legs are facing up into the air

Step 3: Soldering the Component

Figure D: Example of Soldering

WARNING: Soldering with lead solder produces toxic fumes that are harmful to the lungs. Make sure to wear face mask at all times.

Place the soldering iron in your dominant hand and the lead solder in your non dominant hand
Test if the soldering iron is hot enough by lightly wetting the tip of the iron with some of the lead solder
- If the solder instantly melts, you are ready to continue
- Otherwise, clean the iron on the damp sponge and wait
- Various soldering irons require different times to warm up so be patient
Warm the component and conductive part of the circuit board with the tip of the soldering iron
- This is done by gently resting the tip of the iron on the metal for 2 or 3 seconds
- WARNING: Warming components too much can result in component failure
Place the lead solder on the tip of the iron, component leg, and conductive part of the circuit board
Allow for about an inch of the lead solder to flow onto the metal parts of the component and circuit board
Wait 90 seconds for the component to cool
- WARNING: The component, lead solder, and circuit board may still be hot
Repeat 4-6 to the other leg of the component

Step 4: Patience and Practice

Figure E: Good vs Bad Solder

Soldering is a skill that requires lots of practice, so many of your first solders will come out looking like the "Bad Joint" in Figure E. "Good Joints" are formed when the perfect amount of solder is added for the perfect amount of time. Solder can be viewed as an art form; it is easy to teach the basics, but impossible to inspire greatness.

Soldering can be applied to not only components like resistors, but also capacitors, inductors, integrated circuits, and transistors. With patience and practice, you can develop your soldering skills to allow you to make clean, permanent circuits.