IPC-TM-650 EN 2022 试验方法--.pdf - 第673页

GR-78-CORE Figure 1 Interdig itated Comb Pattern Figure 2 With Solder M ask Material in this T est M ethods Manual was voluntarily establis hed by T echni cal Committees of IPC. Thi s mat erial is a dvisory only and its …

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Note:
Note:
IPC-TM-650
Page 2 of 2
Number
2.6.3.4
Subject
Moisture
and
Insulation
Resistance
-
Conformal
Coating
Date
07/03
Revision
A
5.3.3
One
uncoated
specimen
subjected
to
the
same
pro¬
cessing
(except
coating)
as
the
coated
specimens
shall
be
supplied
with
each
lot
of
samples
as
a
test
control.
5.4
Electrical
Connections
5.4.1
Solder
a
single
strand
PTFE
insulated
wire,
using
the
flux
specified
in
4.9,
to
each
pad
of
the
D
comb
pattern.
These
wires
will
be
used
to
connect
each
pad
of
the
desig¬
nated
comb
pattern
to
polarization
and
insulation
resistance
testing.
When
soldering
the
wires
onto
the
pads
care
should
be
taken
to
ensure
that
the
flux
does
not
splatter
onto
the
combs.
A
simple
off-contact
shield
fixture
should
be
used
to
protect
the
test
patterns
from
the
flux
spitting
during
solder¬
ing.
An
alternate
method
is
to
use
gold
plated
alligator
clips.
5.5
Soldering
Flux
Removal
The
flux
shall
not
be
removed.
If
the
flux
has
contaminated
the
comb
pattern
on
the
control,
the
sample
shall
be
discarded
and
a
new
one
used.
It
cannot
be
cleaned
because
it
will
not
represent
the
cleaning
process
that
was
used
prior
to
conformal
coating
application.
5.6
Specimen
Handling
For
the
remainder
of
the
test,
the
surface
of
the
test
specimens
either
uncoated
or
coated
with
conformal
coating
should
not
be
handled
or
exposed
to
any
other
contaminating
influence.
5.7
Procedure
5.7.1
Condition
the
specimens
at
50
±
2
℃
[122
土
3.6°F]
with
no
added
humidity,
for
a
period
of
24
hours.
5.7.2
Testing
5.7.2.1
Allow
the
specimens
to
cool.
Measure
and
record
the
initial
insulation
resistance
measurements
at
ambient
labo¬
ratory
conditions.
Apply
100
VDC
on
the
specimen's
test
points
with
the
resistance
meter
and
take
the
reading
after
one
minute.
On
the
D
comb
pattern,
test
points
1
,
3
and
5
are
connected
to
the
positive
terminal
and
test
points
2
and
4
are
connected
to
the
negative
terminal
of
the
resistance
meter.
5.7.2.2
Place
specimens
in
a
chamber,
in
the
vertical
posi¬
tion
and
under
a
condensation
drip
shield.
Each
chamber
load
shall
contain
at
least
one
uncoated
board
that
is
representa¬
tive
of
the
cleaning
process
used
prior
to
conformal
coating
application
for
each
lot
tested.
5.7.2.3
Close
chambers
door
and
apply
a
50
VDC
polariz¬
ing
bias
to
all
test
patterns.
Electrical
connections
to
speci¬
mens
shall
be
made
so
that
electrical
polarization
voltage
and
the
test
voltage
of
the
same
polarity
are
connected
to
the
same
terminal.
5.7.2.4
Expose
test
specimens
to
20
cycles
of
temperature
and
humidity.
Polarizing
voltage
shall
be
maintained
through¬
out
the
entire
20-cycle
period.
Humidity
shall
be
maintained
at
85%
minimum
through
the
cycles
except
that
when
going
to
low
temperature
in
Step
c
below,
the
humidity
may
drop
to
80%
minimum.
One
cycle
is
as
follows:
a.
Start
test
at
25℃
[77°F]
and
raise
the
temperature
to
65℃
[149°F]
over
a
time
span
of
1
.75
±
0.75
hours.
b.
Maintain
temperature
at
65℃
[149°F]
for
3,
+0.5,
-0
hours
c.
Lower
the
temperature
from
65℃
[1
49°F]
to
25℃
[77°F]
over
1.75
土
0.5
hours
There
shall
be
no
delay
between
cycles.
5.7.3
Measurement/Evaluation
5.7.3.1
Disconnect
50
VDC
polarizing
voltage
source
before
taking
the
insulation
resistance
measurements.
Insulation
resistance
shall
be
read
as
specified
in
5.7.2.
1
.
S.7.3.2
Measure
and
record
the
resistance
at
the
first,
fourth,
seventh
and
tenth
cycle,
between
the
2nd
and
3rd
hour
of
the
high
phase
of
each
cycle.
These
measurements
are
to
be
conducted
without
opening
the
chamber.
5.7.3.3
Upon
completion
of
the
20
cycles,
the
test
comb
patterns
shall
be
maintained
at
25°
±
2
℃
[77°
±
3.6°F]
rela¬
tive
humidity
of
50
土
5%
for
24
hours.
5.7.3.4
After
the
24-hour
stabilization,
the
insulation
resis¬
tance
shall
be
measurements
as
previously
stated
in
section
5.7.2.
1.
5.7.3.5
The
comb
patterns
will
be
examined
for
appearance
and
dielectric
withstanding
voltage
in
accordance
with
IPC-
CC-830.
GR-78-CORE
Figure 1 Interdigitated Comb Pattern
Figure 2 With Solder Mask
Material in this Test Methods Manual was voluntarily established by Technical Committees of IPC. This material is advisory only
and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this
material. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement.
Equipment referenced is for the convenience of the user and does not imply endorsement by IPC.
Page 1 of 4
r
ASSOCIATION
CONNECTING
/
ELECTRONICS
INDUSTRIES
®
221
5
Sanders
Road
Northbrook,
IL
60062-6135
IPC-TM-650
TEST
METHODS
MANUAL
1
Scope
This
test
method
is
used
to
characterize
the
cleanliness
of
printed
wiring
board
fabrication
processes
by
determining
the
degradation
of
electrical
insulation
resistance
under
conditions
of
high
temperature
and
humidity.
This
test
method
examines
the
cleanliness
of
a
test
substrate
prior
to
solder
mask
application,
after
solder
mask
application,
and
after
any
final
metalization
and/or
surface
finish
operation
(e.g.,
HASL
or
OSP),
and
may
be
used
to
demonstrate
the
cleanliness
of
internal
layers
of
a
mulitilayer
board
prior
to
lamination.
2
Applicable
Documents
Telcordia
Technologies
(Formerly
Bellcore)
2.1
Master
Drawings
Telcordia
Technologies
Test
Pattern
(GR-78-CORE,
Figures
14.1
and
14.2)
IPC-B-50
Standard
Test
Board
(Figure
3)
3
Test
Specimens
The
test
specimen
for
this
test
method
is
the
interdigitated
comb
pattern
shown
in
Figures
1
and
2.
This
test
pattern
can
be
produced
in
a
number
of
formats,
but
exists
as
one
of
the
stock
patterns
of
the
IPC-B-50
standard
test
board
(see
Figure
3).
This
comb
pattern
has
0.65
mm
[0.025
in]
lines
and
1.27
mm
[0.050
in]
spacings.
This
test
pattern
is
also
commonly
referred
to
as
the
Bellcore
pattern.
When
used
for
qualification
purposes,
the
base
laminate
will
be
FR-4
epoxy-glass
with
1
7
pm
[0.5
oz
equivalent]
unprotected
copper
metalization.
4
Apparatus
4・1
Clean
test
chamber
capable
of
producing
and
recording
an
environment
of
35℃
±
2
℃
[95°F
±
3.6°F]
and
87.5%
±
2.5%
relative
humidity,
and
that
allows
the
insulation
resis¬
tance
of
the
patterns
to
be
measured
under
these
conditions.
The
chamber
must
be
capable
of
holding
these
conditions
under
load
(i.e.,
with
samples
in
place).
Number
2.6.3.5
Subject
Bare
Board
Cleanliness
by
Surface
Insulation
Resistance
Date
Revision
01/04
Originating
Task
Group
Bare
Board
Cleanliness
Assessment
Task
Group
(5-32c)
NOTE:
NOTE:
Figure 3 IPC-B-50
IPC-TM-650
Page 2 of 4
Number
2.6.3.5
Subject
Bare
Board
Cleanliness
by
Surface
Insulation
Resistance
Date
01/04
Revision
4.2
A
resistance
meter
capable
of
reading
high
resistance
(1012ohms)
with
a
test
voltage
of
100
±
2
volts
DC
or
an
ammeter
capable
of
reading
10-10
amperes
in
combination
with
1
00
volts
DC
power
supply.
Standard
resistors
should
be
used
for
routine
calibration.
5
Test
5.1
Sample
Sizes
•
Eight
test
patterns
are
produced
for
test
with
no
applied
solder
mask
(Figure
1).
•
Eight
test
patterns
are
produced
for
test
with
solder
mask
applied,
imaged,
and
cleaned
(Figure
2).
•
Eight
test
patterns
are
produced
for
test
with
solder
mask
applied
and
the
final
finish
in
place
(e.g.,
HASL).
5.2
Specimen
Identification
Use
a
noncontaminating
method
for
identifying
the
test
specimen
(e.g.,
vibrating
scribe).
During
this
process,
handle
the
specimens
by
the
edges
only
or
using
noncontaminating
gloves.
5.3
Wire
Attach
Cover
the
test
patterns
with
noncontami¬
nating
barrier,
such
as
aluminum
foil
or
plastic
film,
to
prevent
flux
spattering
during
the
wire
attach
process.
Use
water
white
rosin
to
solder
PTFE-insulated
wires
to
the
connection
points
of
the
specimens.
Do
not
attempt
to
remove
the
flux
residues.
Alternatively,
connections
may
be
made
by
mechanical
pressure
connections
(e.g.,
alligator
clips).
Because
of
the
very
high
resistance
levels
typically
used
as
pass-fail
criteria
for
this
method,
a
connector-based
or
other
fixtured
setup
is
not
recommended,
due
to
leakage
currents,
unless
these
systems
can
be
shown
to
have
no
sig¬
nal
degradation
compared
to
hardwiring.
5.4
Placing
in
Chamber
Place
the
specimens
in
the
envi¬
ronmental
chamber
in
a
vertical
position
such
that
the
airflow
is
parallel
to
the
direction
of
the
board
in
the
chamber.
Allow
at
least
2.5
cm
[0.98
in]
between
each
test
sample.
Dress
all
wiring
away
from
the
test
patterns.
Route
the
wires
to
the
outside
of
the
chamber.
Set
the
chamber
temperature
to
35℃
[95°F]
and
85%
minimum
relative
humidity,
with
a
ramp
time
of
not
less
than
one
hour.
There
is
no
electrical
potential
applied
to
any
test
pattern
during
the
first
24
hours
of
test
exposure.
5.5
Resistance
Measurements
After
24
hours
of
test
exposure
with
no
applied
electrical
potential,
measure
the
insulation
resistance
of
each
pattern
using
an
applied
voltage
of
1
00
±
2
volts
DC
and
an
electrification
time
of
60
seconds.
It
is
recommended
that
the
temperature
and
humidity
levels
be
verified
to
be
within
the
recommended
limits
prior
to
beginning
the
resistance
measurements.
Each
comb
pattern
represents
four
test
measurements.
Mea¬
surements
are
made
between
(see
Figure
1):
•
Pad
1
to
Pad
2
•
Pad
3
to
Pad
2
•
Pad
3
to
Pad
4
•
Pad
5
to
Pad
4
Pads
2
and
4
are
at
one
potential
and
Pads
1
,
3,
and
5
are
at
the
opposite
potential
(see
Note
6.3).
All
measurements
are
to
be
taken
with
the
specimens
at
the
test
conditions
and
inside
the
chamber
(in-situ).
Determine
the
means
of
the
dataset
as
outlined
in
5.6.
If,
after
24
hours,
the
results
conform
to
the
specification,
record
the
values
and
terminate
the
test.
If,
after
24
hours,
the
results
do
not
conform
to
the
specifica¬
tion,
then
the
test
may
be
extended
to
96
hours
of
exposure
to
the
test
conditions
with
no
applied
electrical
potential.