FujiFilm FINEPIX A400, Service Manual

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FinePix A400 Service Manual
„ „ „ „ „ Setting temperature during lead-free soldering
• Lead-free solder melting temperature
The melting point of eutectic (Sn-Pb) solder is 183°C, while the melting point of lead-free solder (Sn-Ag-Cu) is 30°C higher
at 220°C.
• Soldering iron tip temperature
The temperature setting for the soldering iron used should be such that the tip of the soldering iron is at the correct
bonding temperature for the connection. This temperature is normally set at around 100°C higher than the melting point of
the solder.
However, the actual temperature should take into account the shape and size of the soldering iron tip, the heat tolerance
of the connection and the workability of that temperature.
• Correct bonding temperature
The correct bonding temperature refers not to the temperature of the heat source, but to the bonding temperature that will
give the best bond strength.
„ „
„ „ „ Precautions when soldering with lead-free solder
• Soldering iron maintenance
Because of the high soldering iron temperature in lead-free soldering, there is rapid carbonization of the flux adhering to
the tip of the soldering iron.
(1) Always cover the tip of the soldering iron with solder when it is not being used.
(2) If the tip is black from carbonization, wipe it gently with a paper towel soaked in alcohol until the solder will wet.
• Uniform heating of the board and components
To ensure that the lead-free solder wets the entire surface of the pattern and the lands despite its poor wetting
characteristics, you must move the tip of the soldering iron over a wide area to raise the temperature of the entire
connection.
„ „
„ „ „ Soldering iron
A soldering iron with a temperature control is best.