A GOOD SOLDER CONNECTION
------------------------------------------------------------------------,
SOLDER FLOWS OUTWARD
AND GRADUALLY BLENDS
/
• When you heat the lead and the circuit board foil at the same
I
time, the solder will flow evenly onto the lead and the foil.
I
The solder will make a good electrical connection between
^the lead and the foil.
_
POOR SOLDER CONNECTIONS
ROSIN
"
//
SOLDER ING
✓
IRON
POSITIONED
SOLDER DOES NOT FLOW
ONTO LEAD. A DARK ROSIN
BEAD SURROUNDS AND IN
SULATES THE LEAD FROM
THE CONNECTION.
Z z
£''' INCORRECTLY
When the lead is not heated sufficiently, the solder
will not flow onto the lead as shown above. To cor
rect, reheat the connection and, if necessary, apply a
small amount of additional solder to obtain a good
connection.
SOLDER APPEARS TO FLOW
INWARD AND SET ON TOP
OF THE FOIL.
SOLDERING
IRON
POSITIONED
INCORRECTLY
ROSIN
FOIL
.................... "T
FT.____
i.......... .............
When the foil is not heated sufficiently the solder will
blob on the circuit board as shown above. To correct,
reheat the connection and, if necessary, apply a small
amount of additional solder to obtain a good connec
tion.
SOLDER BRIDGES
A solder bridge between two adjacent foils is shown
in photograph A. Photograph B shows how the con
nection should appear. A solder bridge may occur if
you accidentally touch an adjacent previously sol
dered connection, if you use too much solder, or if
you “drag” the soldering iron across other foils as you
remove it from the connection. A good rule to follow
is: always take a good look at the foil area around each
lead before you solder it. Then, when you solder the
connection, make sure the solder remains in this area
and does not bridge to another foil. This is especially
important when the foils are small and close together.
NOTE: It is alright for solder to bridge two connec
tions on the same foil.
Use only enough solder to make a good connection,
and lift the soldering iron straight up from the circuit
board. If a solder bridge should develop, turn the
circuit board foil-side-down and heat the solder be
tween connections. The excess solder will run onto
the tip of the soldering iron, and this will remove the
solder bridge. NOTE: The foil side of most circuit
boards has a coating on it called “solder resist.” This
is a protective insulation to help prevent solder
bridges.
