IPC-TM-650 EN 2022 试验方法--.pdf - 第573页
IPC-TM-650 Number Subject Date Revision Page 3 of 3 2.5.6.2 Electric Strength of Printed Wiring Material 8/97 A 7.2 Report the minimum value in percent of requirement if it is below the requirement for average electric s…
IPC-TM-650
Number
Subject Date
Revision
Page 2 of 3
2.5.6.2
Electric
Strength
of
Printed
Wiring
Material
8/97
A
4.7
Large
beaker
or
pan
filled
with
ambient
temperature
dis¬
tilled
water.
4.8
Rack
for
supporting
and
separating
specimens
in
the
50℃
water
bath.
4.9
Lint
free
paper
towels.
5.0
Procedure
5.1
Preconditioning
Unless
otherwise
specified,
the
specimen
shall
be
conditioned
for
48
hours
(+2
hours
-0
hours)
in
distilled
water
maintained
at
50℃
±
2
℃.
Following
this
the
specimen
shall
be
immersed
in
the
ambient
temperature
distilled
water
for
30
minutes
minimum,
4
hours
maximum,
to
achieve
temperature
equilibrium
without
signifi¬
cant
changes
in
moisture
content.
5.2
Test
Conditions
The
test
should
be
performed
at
ambient
temperature,
23℃
土
5
℃.
Relative
humidity
is
not
significant
as
the
tests
are
performed
under
oil.
5.3
Equipment
Set
Up
5.3.1
Set
the
high
voltage
tester
in
accordance
with
the
manufacturer's
instructions
so
that
the
voltage
range
will
be
adequate
for
the
material
being
tested.
5.3.2
Set
up
the
control
for
testing
using
a
500
volt
per
sec¬
ond
rate
of
rise.
5.3.3
Attach
the
leads
(if
not
permanently
wired)
such
that
the
high
lead
is
connected
to
one
electrode
and
the
ground
lead
is
connected
to
the
other
electrode.
5.4
Test
5.4.1
Remove
a
preconditioned
specimen
from
the
ambient
temperature
water
and
wipe
dry
with
a
lint
free
paper
towel.
5.4.2
Determine
and
record
the
thickness
of
the
specimen
at
four
locations
1
inch
from
the
edge
at
the
midpoint
of
each
side.
5.4.3
Insert
the
specimen
into
the
test
fixture
centering
it
to
reduce
chances
of
flashover.
5.4.4
Operate
the
tester
such
that
the
voltage
is
applied
with
a
500
volts
per
second
increase
and
observe
the
point
at
which
the
tester
indicates
a
breakdown.
5.4.5
Record
the
breakdown
voltage
to
the
nearest
.1
KV
for
values
over
1
0
KV
and
to
at
least
the
nearest
5%
for
all
lower
values.
5.4.6
Remove
the
specimen
from
the
oil
medium
and
verify
that
a
breakdown
has
occurred.
If
none
is
apparent
reinsert
the
specimen,
carefully
centering
it,
and
retest
as
in
5.4.4
and
5.4.5.
Note:
If
flashover
occurs,
either
a
larger
specimen
or
new
oil
must
be
used.
4.7
Test
the
remaining
two
specimens
as
in
5.4.1
through
5.4.6.
6.0
Calculations
6.1
Calculate
the
average
thickness
for
each
specimen
from
the
four
individual
values
measured.
6.2
Determine
the
electric
strength
in
volts
per
mil
for
each
specimen
by
dividing
the
breakdown
voltage
expressed
in
kilovolts
by
the
thickness
express
in
inches.
i-o
6.8
KV
-
.005
inch
1000
V
v
x
1
inch
1
000
mils
=
1360
v/mil
6.3
Determine
the
average
electric
strength
by
averaging
the
individual
values
for
each
specimen.
Round
the
average
to
the
nearest
1
0
volts/mil.
6.4
If
any
specimen
falls
below
the
specification
minimum,
calculate
the
percentage
of
the
requirement:
es
•
Lowest
Value
2m
in
=
—
—
——
X
100%
Spec
Value
e.g.
Value
=
670
volts
per
mil
Specification
=
750
volts
per
mil
ESmin
=
染
X
1
00%
=
.893
X
1
00%
=
.89
X
1
00%
=
89%
7.0
Report
7.1
Report
the
average
value
for
electric
strength
in
volts
per
mil
to
the
nearest
10
volts
per
mil.
IPC-TM-650
Number
Subject Date
Revision
Page 3 of 3
2.5.6.2
Electric
Strength
of
Printed
Wiring
Material
8/97
A
7.2
Report
the
minimum
value
in
percent
of
requirement
if
it
is
below
the
requirement
for
average
electric
strength.
7.3
Report
the
actual
thickness
range
of
the
material
tested
including
the
minimum
and
maximum
individual
thickness
measurements.
7.4
Report
any
anomalies
in
the
test
or
any
variations
from
the
prescribed
procedures
or
tolerances.
8.0
Notes
8.1
This
test
method
may
be
modified
to
an
air
medium
to
predict
performance
in
normal
environments
more
accurately,
however,
unless
the
electrode
is
effectively
guarded,
the
breakdown
will
generally
occur
in
air.
8.2
For
testing
the
effect
of
copper
foil
on
clad
laminate
under
0.005
inch
it
is
suggested
that
two
inch
circular
elec¬
trodes
be
left
on
the
4
inch
X
4
inch
specimen
by
etching.
The
ground
electrode
may
be
slightly
larger
to
assure
registration.
8.3
For
materials
which
are
compressible,
a
standard
pres¬
sure
of
25
PSI
is
to
be
used
for
determining
specimen
thick¬
ness.
The Institute for Interconnecting and Packaging Electronic Circuits
2215 Sanders Road • Northbrook, IL 60062
Material in this Test Methods Manual was voluntarily established by Technical Committees of the 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 the IPC.
Page 1 of 3
IPC-TM-650
TEST
METHODS
MANUAL
Number
2.5.6.3
Subject
Dielectric
Breakdown
Voltage
and
Dielectric
Strength
Date
Revision
10/86
Originating
Task
Group
N/A
1
Scope
These
methods
are
designed
for
use
in
determin¬
ing
the
dielectric
strength
of
solid
electrical
insulating
materi¬
als.
2
Applicable
Documents
None
3
Test
Specimens
3.1
Dimensions
The
specimens
shall
be
of
such
a
diam¬
eter
that
flashover
will
not
occur.
This
usually
means
that
the
diameter
should
be
76
mm
or
more.
3.2
Thick
Solid
Materials
The
breakdown
voltage
of
thick
solid
materials
may
be
so
high
that
special
test
specimens
cut
or
molded
in
reduced
thickness
may
be
required.
3.3
At
Various
Thicknesses
When
it
is
desired
to
deter¬
mine
the
dielectric
strength
for
different
thicknesses
of
a
mate¬
rial,
it
is
necessary
to
test
each
different
thickness,
unless
the
variation
due
to
thickness
is
already
known.
3.4
Exceptional
Conditions
The
special
sizes
of
speci¬
mens
required
for
determining
dielectric
strength
under
exceptional
conditions
shall
be
as
specified
in
the
material
specification.
4
Equipment/Apparatus
4.1
Transformer
The
desired
test
voltage
may
be
most
readily
obtained
by
a
step-up
transformer
energized
from
a
variable
low-voltage
source.
The
transformer
and
its
control¬
ling
equipment
shall
be
of
such
size
and
design
that
the
test
specimen
in
circuit,
the
crest
factor
(ratio
of
maximum
to
mean
effective)
of
the
test
voltage
shall
not
differ
by
more
than
土
5%
from
that
of
a
sinusoidal
wave
over
the
upper
half
of
the
range
of
test
voltage.
The
crest
factor
may
be
checked
by
means
of
a
sphere
gap
or
peak-reading
voltmeter
in
conjunc¬
tion
with
a
r.m.s.
voltmeter.
For
test
specimens
of
small
capacitance,
a
testing
transformer
as
small
as
500-volt-
ampere
rating
must
be
used.
Where
the
wave-form
cannot
be
determined
conveniently,
a
transformer
having
a
rating
of
not
less
than
2
kilovolt
amperes
shall
be
used
for
voltages
not
exceeding
50,000
volts.
Tests
shall
be
made
at
commercial
power
frequencies.
When
a
transformer
is
used
at
voltages
lower
than
its
full
rating,
the
current
drawn
from
the
high-
voltage
winding
should
not
exceed
the
full-load
full-voltage
current
rating.
4.2
Circuit
Breaker
The
test
transformer
circuit
shall
be
protected
by
an
automatic
circuit-breaking
device
designed
to
open
instantaneously
on
the
current
produced
by
breakdown
of
the
test
specimen.
Excessive
flow
of
current
at
the
time
of
breakdown
causes
pitting
and
heating
of
the
electrodes
and
thereby
increases
the
work
of
electrode
maintenance
and
time
of
testing.
4.3
Voltage
Control
The
rate
of
voltage
rise
shall
not,
for
short
time
tests,
vary
more
than
±
25%
from
the
specified
rate.
Control
of
voltage
may
be
secured
in
one
of
several
ways:
a.
Variable-ratio
autotransformer
b.
Resistance-potential
divider
c.
Generator-field
regulation
d.
Induction
regulator
Preference
should
be
given
to
equipment
having
an
approxi¬
mately
straight-line
voltage-time
curve
over
the
desired
oper¬
ating
range.
Motor
drive
with
variable
speed
control
should
be
preferred
to
manual
drive
because
of
the
difficulty
in
maintain¬
ing
reasonable
uniform
rate
of
voltage
rise
with
the
latter.
4.4
Voltmeter
The
voltage
shall
be
measured
by
an
approved
method,
which
gives
root-mean-square
values,
preferably
by
means
of
a.
A
voltmeter
connected
to
the
secondary
of
a
separate
potential
transformer
b.
An
electrostatic
voltmeter
in
the
secondary
circuit
c.
A
voltmeter
connected
to
a
well-designed
tertiary
coil
in
the
test
transformer.
A
voltmeter
connected
to
the
primary
side
of
the
testing
transformer
may
be
used
only
if
the
ratio
of
transformer
does
not
change
appreciably
with
load.
4.5
Electrodes
The
electrodes
used
for
thin
solid
materials
(sheets
and
plates)
shall
be
metal
disks
5
mm
in
diameter
and
25
mm
in
length,
with
the
edges
rounded
to
a
radius
of
6.4
mm.
The
electrodes
used
for
thick
solid
materials
shall
be
metal
disks
25
mm
in
diameter
and
25
mm
in
length,
with
edges
rounded
to
a
radius
of
3.2
mm.
The
electrodes
for
tapes
and
sheet
materials
to
be
compared
with
tapes
shall
be