Sharp LC-19SH7E/RU, Service Manual, Page: 3 / 267

LC-19SH7E/RU, LC-26SH7E/RU, LC-32SH7E/RU, LC-42SH7E/RU
3
Precautions for using lead-free solder
Using lead-free wire solder
• When fixing the PWB soldered with the lead-free solder, apply lead-free wire solder. Repairing with conventional lead wire solder may cause
damage or accident due to cracks.
As the melting point of lead-free solder (Sn-Ag-Cu) is higher than the lead wire solder by 40 °C, we recommend you to use a dedicated soldering
bit, if you are not familiar with how to obtain lead-free wire solder or soldering bit, contact our service station or service branch in your area.
Soldering
• As the melting point of lead-free solder (Sn-Ag-Cu) is about 220 °C which is higher than the conventional lead solder by 40 °C, and as it has
poor solder wettability, you may be apt to keep the soldering bit in contact with the PWB for extended period of time. However, Since the land
may be peeled off or the maximum heat-resistance temperature of parts may be exceeded, remove the bit from the PWB as soon as you
confirm the steady soldering condition.
Lead-free solder contains more tin, and the end of the soldering bit may be easily corroded. Make sure to turn on and off the power of the bit as
required.
If a different type of solder stays on the tip of the soldering bit, it is alloyed with lead-free solder. Clean the bit after every use of it.
When the tip of the soldering bit is blackened during use, file it with steel wool or fine sandpaper.
• Be careful when replacing parts with polarity indication on the PWB silk.