Textron Cessna 182S - Page 139

CESSNA
AIRCRAFT
COMPANY
MODEL 182/T182
WIRING DIAGRAM MANUAL
(3) Component
leads on opposite
side of printed circuit
board may be clinched
or extend straight
through approximately
0.03 of an inch. Refer
to Figure 203.
(4)
Horizontally mounted ceramic components
shall touch the board at least at one point.
Maximum
clearance
of ceramic components
is 0.015
inch. Glass components
shall not rattle
against the
board during vibration
and shall not touch the board. Maximum
clearance of 0.03 inch between
glass components and board
shall be observed. Refer
to Figure 202.
(5) For
clearance requirements
on circuit boards
with plated-thru-holes
refer to Figure
204.
(6) Protect adjacent
areas with thermal
shunts. Refer
to Figure 206 for typical
thermal shunts.
(7)
Solder with
low melting
point
solder.
(8)
Solder joints shall
be free of cracks,
fractures and projections.
Porosity, voids,
and foreign
materials in the solder
joint shall not exceed 25% of the total
area between the lead and the
wall of the
plated-thru-hole. Solder
wetting of the component
lead and
of the hole wall to the
pad
must be evident.
K. Soldering of sleeved or insulated
terminals shall be accomplished in the
following manner.
(1) Insulation
tubing shall
be installed over wires,
leads and harnesses
prior to their attachment
to
terminals of
relays, connectors, and similar items which
are not protected by insulating grommets
or potting.
(2)
Insulation tubing shall
be pushed back
far enough from the
terminal so as not to
interfere with
the
securing and soldering
operations.
(3) Insulation
tubing shall be slipped
back, after the
solder has solidified
and cooled and the joint
is
cleaned, over the
wires and terminals and, where
applicable, heat shrunk.
(4) After installation,
the tubing shall extend
above the stripped
portion of the attached
conductor;
a distance
equal
to or greater
than the
tubing diameter.
L. Soldering of solder cup terminals shall
be accomplished in the following manner.
Refer to Figure 207
for examples
of acceptable and
unacceptable solder joints.
(1) The solder
cup shall contain a sufficient amount of
precut solder to completely fill the cup when
solder is
melted and the tinned wire inserted
into the bottom of the cup.
(2) Sufficient
heat shall be applied
after the cup is filled
with solder to assure
that the flux has boiled
up
and out of the bottom
of the cup. It
is desired that continuous
soldering iron
contact be
maintained throughout
the soldering
operation.
(3)
The tinned wire
or lead shall not
be bent or formed
for solder cup
termination.
(4) All
conductors terminating
in a solder
cup shall
bottom in the
cup.
(5) Insulating
clearance shall
be maintained, clearance
shall be referenced
from the point of
entry
into the cup.
(6) The
solder shall follow
the contour of the cup
entry slot and shall
not spill over or adhere
to the
sides of the cup. Connection
may be made
with either a resistance
or conduction
type soldering
iron. When a conducting type soldering
iron is used, the slight tinned effect occurring
at the point
where the tip
contacts the base of
the cup is normal
and is acceptable provided
there are no
peaks, globules,
or excessive buildup
of solder.
(7) Excess solder
in the form of buildup
or overflow on a
hollow terminal must
not be in excess as
to
cause
a short circuit between
pins of other
conductors and excess
solder cannot
interfere with
the mechanical function of the terminals.
4. Component
Removal (Solder
Removal Technique)
WARNING: XYLENE
IS TOXIC. DO NOT BREATHE
VAPORS. USE IN WELL
VENTILATED
AREA FREE FROM
SPARKS, FLAME OR HOT SURFACES.
WEAR SPLASH GOGGLES,
SOLVENT RESISTANT
GLOVES AND
OTHER PROTECTIVE
GEAR. IN CASE OF EYE
CONTACT, FLUSH
WITH WATER
AND SEEK MEDICAL ATTENTION.
IN CASE OF SKIN
CONTACT, WASH
WITH SOAP AND
WATER.
A. Printed circuit
board assemblies are coated with an approved
silicone resin coating. Before removing
a component,
carefully soften this coating with xylene
or equivalent solvent. Remove resin from
component and solder joint with a cleaning pad.
20-10-03 Page 205
© Cessna Aircraft
Company
Mar 1/2004