Thursday, February 4, 2016

Week 3: Notes on Soldering

What is Solder?
  • Solder is a a alloy that is a substance composed of two or more metals that typically comes as a long, thin wire in spools or tubes. It can also be use as a verb as it means to join two pieces of metal in what is called a solder point.
alt text
  • It is highly bendable to the point of a liquid string and easily breaks by a simple pull of the hand
  • Composed of mostly lead (Pb), tin, (Sn), and a few other trace metals
  • Lead is harmful to humans in large amounts, but it's chosen as the go-to metal for creating solder joints the best
  • Lead-free solder has become the norm in electronics manufacturing
  • Composed of mostly tin and other trace metals such as silver and copper, and is very similar to it's counterpart
  • RoHS (Restriction of Hazardous Substances Directive)is the symbol used for it
  • Overall, it;s one person's own decision what to use and take the rick with the reward
  • Lead-free solder isn't without fault as since it's mostly composed of tin, it has a higher melting point and thus requires a higher heat, and sometimes needs a little help
  • Flux Core: A chemical agent that aids in the flow of lead-free solder; it helps to achieve the same effect as does regular leaded solder, but can sometimes be more expensive than leaded solder
  • These two types aren't the only types as there are other metals to chose aside from lead or tin 
  • Solder comes in varying sizes, but the best for small electronics (Especially for this class) is the thinner version where it;s easier to maneuver it around the components of a small circuit board
Soldering Irons

  • A Soldering Iron is a Hand Tool that heats up so that it may be used as a conductor when melting solder onto a circuit board or to create a solder joint
alt text
  • For this class, we'll be using a simple 30-40 Watt iron
  • Tips: the part of the iron that heats up and allows solder to flow around the two components being joined. We'll be using a small, pointed tips for better precision on our boards, but they come in other variations according to ones needs


  • Wand: This part of the iron that holds the tip, is the insulator for the heating coils and wires, and has a rubber grip that prevents the tip from transferring heat to the outside of the wand, and protects your hand from the heat of the metal tip

  • Base: This is a conductor box you can use to adjust the amount of heat conducted into the tip to match the varying alloys you can experiment with but for this class we just used a regular electrical socket because the heat is already set within the soldering irons required for the class, But, this is something you can look in to if you have a soldering iron that can vary in heat
  • Stand (Cradle): This is a stand used to house the soldering iron when not in use while it's plugged in. Leaving an iron on without placing it in a metal stand can cause a fire, or burn your hand when you're not paying attention to it as it rolls along the table, or could possibly touch it;s own electrical chord and melt the wiring. ALWAYS USE THE METAL STAND!!!

alt text
  • Brass Sponge: As the soldering iron heats up, and corrodes and oxidizes, turning your tip black and begin to reject solder. This 'sponge' scrapes off the gunk that builds at the tip of your iron, which causes the oxidization. The more traditional method is to use a wet sponge, but it'll wear out the tip due to the change of heat causing your tip to expand and contract. This can cause a hole o from in your tip; Once there is a hole in the tip, it is no good for soldering. The brass sponge works much better than a regular sponge, but if you don't have this item, a regular sponge is better than nothing.

brass sponge

  • Solder Wick: This is the equivalent of an eraser for solder. By eating up this thin strip of copper, you can attract solder on a circuit board to remove it, and it's used to help in fixing any problems that may occur like placing a compennt wrong, or if a bridge has formed betwen components which could cause a short curcuit which is bad

alt text
  • Flush Cutters: Cutters that allow you to trim legs of components you've soldered onto a board, and to make it look cleaner
  • Safety Glasses: Unless you need glasses to see, I would suggest safety glasses just in case a bit of solder flies up from removing a tip to quickly and flicking upwards; let's protect our money makers shall we?
How to Solder Tips:

  • When you solder, be careful not to overheat your PCB (Circuit Base) boards and cause your boards to burn out, or cause a fire
  • As depicted above, you want your solder to create a Volcano or Hershey's Kiss shape when creating a soldering joint
  • Also, it should be shiny and glossy when connected to create a good connection whitin the circuit
  • A tip to do is clean off your tip with your brass sponge and add a bit of solder onto the tip
  • Connect to your board and component for a second to heat up the metal, connect your solder, and let the heat wrap your solder around the joint, then quickly lift off your board
  • Since you'll be using both hands, use a 'third arm' or type of pliers that lock so you can keep your two components in place
  • Pay attention to your diagram when connection your board, and know which side you should slide your component through and which side to add solder


For more tips on How to Solder, and a more visual understanding of soldering, check out the links Below:

Spark Fun Video on Soldering Basics


    No comments:

    Post a Comment