Philips PM 5390 - Chip Components; Working Method; Replacement of Chip Components

9-2
Suitable
soldering irons
should
have
temperature
control and
different
types
of
nozzles
(pin point
tips)
^
e.g.
Weller Magnastat
WTCP or
WECP,
Ersa TC
70/24 V.
If a
higher
wattage-rating
soldering
iron
is used on
the etched circuit
boards
(especially on
the
RF
-units
),
excessive
heat
can cause
the
etched circuit
wiring to separate from the
board base material.
In
general use
short-time
heating with high tip
temperature at a small
point,
avoid long time heating.
Chip
components
—
Do
not use
unsoldered
chips again
—
For replacement
take
only specified
components
—
Do not
use any
adhesive to
fix components
—
Replaced
chips must
positioned
flat on the
pcb before
soldering
starts
—
Use only
resin-core
solder
tin
with
silver
(60,
36,
4 Ag)
Working
method:
—
Carefully
unsolder both
soldering tags of the
chip component.
Avoid
to
lift printed conductor
on
the
pcb.
—
Remove
all
superfluous material. Use a
sucking iron or
sucking copper lltze
wire.
—
Locate
the
replacement chip
exactly in place
—
An
additional
fixing point made by
solder-tin
could
be
efficient.
—
Solder
each
tag to
the
relevant printed
conductor
on
the pcb
—
After a
short cooling period
resolder
again the
first soldered joint (tension
release
of the chip).
Fig.
14
Replacement
of
chip
components