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What Good Soldering Looks Like
A good solder connection should be bright, shiny,
smooth, and uniformly flowed over all surfaces.
Soldering a PC board
1. Solder all components from the copper foil side
only. Push the soldering iron tip against both the
lead and the circuit board foil.
2. Apply a small amount of solder to the iron tip.
This allows the heat to leave the iron and onto
the foil.
Immediately apply solder to the
opposite side of the connection, away from the
iron.
Allow the heated component and the
circuit foil to melt the solder.
3. Allow the solder to flow around the connection.
Then, remove the solder and the iron and let the
connection cool. The solder should have flowed
smoothly and not lump around the wire lead.
4. Here is what a good solder connection looks like.
Types of Poor Soldering Connections
1. Insufficient heat - the solder will not flow onto
the lead as shown.
2. Insufficient solder - let the solder flow over the
connection until it is covered. Use just enough
solder to cover the connection.
3. Excessive solder - could make connections
that you did not intend to between adjacent foil
areas or terminals.
4. Solder bridges - occur when solder runs
between circuit paths and creates a short circuit.
This is usually caused by using too much solder.
To correct this, simply drag your soldering iron
across the solder bridge as shown.
A poorly soldered joint can greatly affect small current flow in circuits and can cause equipment failure. You can
damage a PC board or a component with too much heat or cause a cold solder joint with insufficient heat.
Sloppy soldering can cause bridges between two adjacent foils preventing the circuit from functioning.
Solder
Soldering Iron
Foil
Solder
Soldering Iron
Foil
Component Lead
Soldering Iron
Circuit Board
Foil
Rosin
Soldering iron positioned
incorrectly.
Solder
Gap
Component Lead
Solder
Soldering Iron
Drag
Foil
