2
THE CORRECT WAY TO SOLDER
Always use the soldering iron to heat
the joint, not the solder. A small
amount of fresh solder on the tip will
help conduct heat to the joint faster.
The solder should be heated by the
joint so it will flow into and around the
connection resulting in a stronger joint.
THE AMOUNT OF SOLDER AND QUALITY CONTROL
a) Minimum amount of solder.
b) Optimum amount of solder. The solder should cover the pad and wire.
There should be some wicking action of the solder up onto the wire.
The surface of the solder should be smooth and shiny.
c) Excessive solder, hides the connection from being checked. There is
also the possibility that solder could bridge between traces and cause
a short circuit.
DIFFERENT TYPES OF BAD SOLDER JOINTS
a) Bad soldering of terminal wire. The wire was not heated enough and the
solder did not wet the top. This wire could pull away from the joint.
b) Bad soldering of PCB trace. The trace was not heated enough to let the
solder wet and flow over the surface of the trace. The solder can pull
away from the trace if strained. This can also occur if the trace was not
cleaned or not enough flux was used.
c) Bad soldering of terminal wire and PCB trace. This is a cold solder
joint where the soldering iron was not held on the joint long enough to
heat the joint sufficiently and where some movement of the joint could
have occurred before the solder cooled. It will appear to have a rough
textured surface. This can be corrected by reheating the joint until the
solder flows and adding a small amount of flux.
SELECTION OF WELLER
®
ST SERIES TIPS
Weller
®
tips are solid copper, plated with iron, nickel, and chromium. The chromium is eliminated from the working area and
the tips are pre-tinned with tin/lead solder. The nickel and chromium protect the shank from corrosion and solder creep. The
Weller
®
WLC100 uses the ST series tips.
CARE OF WELLER
®
SOLDERING TIPS
1. Keep tip tinned; wipe only before using.
2. Use rosin or activated rosin fluxes. Acid type fluxes will greatly reduce tip life.
3. Remove tip and clean with suitable cleaner for flux used. The frequency of cleaning will depend on the type of work
and usage. Tips in constant use should be removed and cleaned at least once a week.
4. Dont try to clean tip with abrasive materials and never file tip; to do so will greatly reduce tip life. Tip wettability is
affected by contact with organics such as plastic rosins, silicone grease, and other chemicals. If the tip becomes
unwettable it may be cleaned with a Weller® Polishing Bar Part Number WPB1. Do not overdo this or the iron
plating will be removed and the tip will be ruined. Re-tin tip immediately to prevent oxidation.
5. Dont remove excess solder from heated tip before storing. The excess solder will prevent oxidation of the wettable
surface when the tip is reheated.
