Panasonic JB-3300 Technical Manual page 42

Precautions New Handling MOS ICs
The LSI used on the control board is called MOS IC, which requires
handling different from that for other ICs because of its structure. Its
internal electrodes break because of voltage (static electricity and
leakage from a soldering iron) from the exterior. Although reliability is
increased by providing protective transistors for internal electrodes,
there are cases where protective transistors are broken when the voltage
1s too large. When servicing, storing and during return shipment, the MOS
IC should be handled with extreme care, with thorough attention paid to
the following points:
(a) There are cases where voltage is due to leakage from the soldering
iron during soldering. Use a high insulation type soldering iron, or
if an ordinary soldering iron is used, ground it to the chassis as
shown in Figure 5-17.
(b) Do not carry out soldering or replacement while the power is on.
(c) Be sure to attach the MOS IC to a black electroconductive sponge
during storage or return shipment. (The MOS IC to be repaired should
be attached to the electroconductive sponge before shipment (Figure
5-28) .)
(d) Do not place the MOS IC on plastics liable to be charged with static
electricity. Do not attach it to styrofoam instead of an
electroconductive sponge.
Be sure to ground . fc
the soldering iron
ae
Sponge
Figure 5-17
LSI IC Replacing Procedures
Use a soldering iron with a fine tip of around 30 W and a solder
sucker. If the soldering iron is not a suction type, suck the
solder by using a plunger or braided wire used to coat the
display unit grounding.
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