Page 99 - Electronic Mechanic - TP - Volume - 2

ELECTRONICS MECHANIC - CITS

A Soldering Iron

• A soldering iron is used to heat the connections to be soldered.
• For electronic circuits, you should use a 25- to 40-watt (W) soldering iron.
• Higher wattage soldering irons are not necessarily hotter; they are just able to heat larger components.
• A 40-W soldering iron makes joints faster than a 25-W soldering iron does.

Soldering Process

1 Solder needs a clean surface on which to adhere
• Buff the copper foil of a PC board with steel wool before soldering.
• Remove any oil, paint, wax, etc. with a solvent, steel wool, or fine sandpaper.
2 To solder, heat the connection with the tip of the soldering iron for a few seconds, then apply the solder.

• Heat the connection, not the solder.
• Hold the soldering iron like a pen, near the base of the handle.
• Both parts that are being soldered have to be hot to form a good connection.
3 Keep the soldering tip on the connection as the solder is applied.
• Solder will flow into and around well-heated connections.
• Use just enough solder to form a strong connection.4. Remove the tip from the connection as soon as the
solder has flowed where you want it to be. Remove the solder, then the iron.
5 Don’t move the connection while the solder is cooling.
6 Don’t overheat the connection, as this might damage the electrical component you are soldering.

• Transistors and some other components can be damaged by heat when soldering. A crocodile clip can be
used as a heat sink to protect these components.

82
CITS : E & H - Electronics Mechanic - Exercise 141