Heathkit IO-4205 - Page 14

Page 12
A GOOD SOLDER CONNECTION
~-------------------,
S OLDER FLOWS OUTWARD
AND GRADUALLY BLEND S
WITH
THE FOIL AND
THE LE AD .
,')
/
,' /
// , (_;; OLDER IN G
',, IRON
,~;~ P OS ITIO N ED
CO RR EC TL Y
I
I
I
I
I
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
1 The solder will make a good electrical connection between I
Lt~ ~~~ ~ !!!i~ ___________ -~
POOR SOLDER CONNECTIONS
~----------------------------~-----,
I SOL DE R DOES NO T FL OW / / I
ONT O LEA D. A DAR K RO S IN , ,') ,' SOLDERING
I BEAD SURROUN DS AND I N- // ,' SO LD ER APPEARS TO FLOW //,. - ........_ IR ON
I
SUL ATE S THE L EA D FRO M ROS IN ,<; , I N WA RD AND S ET ON TOP / , ', PO SIT IONED
T
HE CONNECT I ON . //,'S OLDERING OF TH E FO IL . //,' IN CO RRE C TL Y
'
'' "" IRON '
I FO IL //• PO S ITIO N ED
I ,,, , I NC ORRE C TL Y
I When the lead is not heated sufficiently, the solder
I will not flow onto the lead as shown above. To cor-
When the foil is not heated sufficiently the solder will
blob on the circuit board as shown above. To correct,
1 rect, reheat the c onnection and , if necessary, apply a reheat the connection and , if necessary, apply a small 1
1 small amount of additional solder to obtain a good amount of additional solder to obtain a good connec- I
Lc~~c~r:_ _____________ _!~;.... ______________ .J .~
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:
alwa ys take a good look at the foil area around each
lead before you solder it. Then , when you solder the
connection , make sure the sold er 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." Th is
is a protective
insulation to help prevent solder
bridges.
B
A
SOLDER
BRIDGE