Panasonic SC-UA7E, Service Manual

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2.2. General description about Lead Free Solder (PbF)
The lead free solder has been used in the mounting process of all electrical components on the printed circuit boards used for this
equipment in considering the globally environmental conservation.
The normal solder is the alloy of tin (Sn) and lead (Pb). On the other hand, the lead free solder is the alloy mainly consists of tin
(Sn), silver (Ag) and Copper (Cu), and the melting point of the lead free solder is higher approx.30 degrees C (86

F) more than that
of the normal solder.
Definition of PCB Lead Free Solder being used
Service caution for repair work using Lead Free Solder (PbF)
• The lead free solder has to be used when repairing the equipment for which the lead free solder is used.
(Definition: The letter of “PbF” is printed on the PCB using the lead free solder.)
• To put lead free solder, it should be well molten and mixed with the original lead free solder.
• Remove the remaining lead free solder on the PCB cleanly for soldering of the new IC.
• Since the melting point of the lead free solder is higher than that of the normal lead solder, it takes the longer time to melt the
lead free solder.
• Use the soldering iron (more than 70W) equipped with the temperature control after setting the temperature at 350±30 degrees
C (662±86

F).
Recommended Lead Free Solder (Service Parts Route.)
• The following 3 types of lead free solder are available through the service parts route.
RFKZ03D01K-----------(0.3mm 100g Reel)
RFKZ06D01K-----------(0.6mm 100g Reel)
RFKZ10D01K-----------(1.0mm 100g Reel)
Note
* Ingredient: tin (Sn), 96.5%, silver (Ag) 3.0%, Copper (Cu) 0.5%, Cobalt (Co) / Germanium (Ge) 0.1 to 0.3%
2.3. Grounding for electrostatic breakdown prevention
• As for parts that use optical pick-up (laser diode), the optical pick-up is destroyed by the static electricity of the working environ-
ment.
Repair in the working environment that is grounded.
2.3.1. Worktable grounding
• Put a conductive material (sheet) or iron sheet on the area where the optical pickup is placed and ground the sheet.
2.3.2. Human body grounding
• Use the anti-static wrist strap to discharge the static electricity form your body Figure 2-1.
Figure 2-1
The letter of “PbF” is printed either foil side or components side on the PCB using the lead free solder.
(See right figure)