Sharp LC-20B2UA, Руководство по обслуживанию

Страница: 5 / 60

5
LC-20B2UA
Precautions for using lead-free solder
1 Employing lead-free solder
"Main PWB" of this model employs lead-free solder. The LF symbol indicates lead-free solder, and is attached
on the PWBs and service manuals. The alphabetical character following LF shows the type of lead-free solder.
Example:
2 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 40ºC, we recommend
you to use a dedicated soldering bit, if you are not familiar with how to obtain lead-free wire solder or soldening
bit, contact our service station or service ranch in your area.
3 Soldering
As the melting point of lead-free solder (Sn-Ag-Cu) is about 220ºC which is higher than the conventional lead
solder by 40ºC, and as it has poor solder wettabillty, 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 excoeded, remove the bit from the PWB as soon as you conurm the steady
soldering condition.
Lead-free solder contains more tin, and the end of the soldering bit may be easily corroded. Make sure to tum 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.
Becareful when replacing parts with polarity indication on the PWB silk.
L F a
Indicates lead-free solder of tin, silver and copper.
Lead-free wire solder for servicing
Part No,
★
Description Code
ZHNDAi123250E J
φ
0.3mm 250g(1roll) BL
ZHNDAi126500E J
φ
0.6mm 500g(1roll) BK
ZHNDAi12801KE J
φ
1.0mm 1kg(1roll) BM